No evidence for a role of Ile587Val polymorphism of EIF2B5 gene in multiple sclerosis in Kashmir Valley of India.

PubMed

Zahoor, Insha; Asimi, Ravouf; Haq, Ehtishamul

2015-12-15

Multiple sclerosis (MS) is an inflammatory neurodegenerative disease of the nervous system with a profound genetic element. It is already known that alterations in Eukaryotic Translation Initiation Factor 2B (EIF2B) gene encoding the five subunits of eIF2B complex cause Vanishing White Matter (VWM) disease of the brain and emerging evidences have advocated certain resemblances between MS and VWM in terms of clinical and epidemiological characteristics, thus validating the association study between EIF2B and MS. Moreover, a recent study has implicated EIF2B5 Ile587Val (rs843358) polymorphism as a susceptibility factor for MS. In order to investigate the association of EIF2B5 Ile587Val polymorphism with MS susceptibility in Kashmir region in India, we screened EIF2B5 Exon 13 in 30 MS patients and 65 controls (a total of 95 participants). During the present course of study, we could not find statistically significant difference in the frequency of Ile587Val between MS patients and controls, thus indicating that such alteration does not appear to influence MS development in Kashmiri population. Our results provide evidence against a major role for Ile587Val polymorphism in MS susceptibility. Copyright © 2015 Elsevier B.V. All rights reserved.

CRISPR/Cas9-mediated conversion of human platelet alloantigen allotypes

PubMed Central

Zhang, Nanyan; Zhi, Huiying; Curtis, Brian R.; Rao, Sridhar; Jobaliya, Chintan; Poncz, Mortimer; French, Deborah L.

2016-01-01

Human platelet alloantigens (HPAs) reside on functionally important platelet membrane glycoproteins and are caused by single nucleotide polymorphisms in the genes that encode them. Antibodies that form against HPAs are responsible for several clinically important alloimmune bleeding disorders, including fetal and neonatal alloimmune thrombocytopenia and posttransfusion purpura. The HPA-1a/HPA-1b alloantigen system, also known as the PlA1/PlA2 polymorphism, is the most frequently implicated HPA among whites, and a single Leu33Pro amino acid polymorphism within the integrin β3 subunit is responsible for generating the HPA-1a/HPA-1b alloantigenic epitopes. HPA-1b/b platelets, like those bearing other low-frequency platelet-specific alloantigens, are relatively rare in the population and difficult to obtain for purposes of transfusion therapy and diagnostic testing. We used CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/CRISPR associated protein 9) gene-editing technology to transform Leu33+ megakaryocytelike DAMI cells and induced pluripotent stem cells (iPSCs) to the Pro33 allotype. CD41+ megakaryocyte progenitors derived from these cells expressed the HPA-1b (PlA2) alloantigenic epitope, as reported by diagnostic NciI restriction enzyme digestion, DNA sequencing, and western blot analysis using HPA-1b–specific human maternal alloantisera. Application of CRISPR/Cas9 technology to genetically edit this and other clinically-important HPAs holds great potential for production of designer platelets for diagnostic, investigative, and, ultimately, therapeutic use. PMID:26634302

Mutation of Neuron-Specific Chromatin Remodeling Subunit BAF53b: Rescue of Plasticity and Memory by Manipulating Actin Remodeling

ERIC Educational Resources Information Center

Ciernia, Annie Vogel; Kramár, Enikö A.; Matheos, Dina P.; Havekes, Robbert; Hemstedt, Thekla J.; Magnan, Christophe N.; Sakata, Keith; Tran, Ashley; Azzawi, Soraya; Lopez, Alberto; Dang, Richard; Wang, Weisheng; Trieu, Brian; Tong, Joyce; Barrett, Ruth M.; Post, Rebecca J.; Baldi, Pierre; Abel, Ted; Lynch, Gary; Wood, Marcelo A.

2017-01-01

Recent human exome-sequencing studies have implicated polymorphic Brg1-associated factor (BAF) complexes (mammalian SWI/SNF chromatin remodeling complexes) in several intellectual disabilities and cognitive disorders, including autism. However, it remains unclear how mutations in BAF complexes result in impaired cognitive function. Post-mitotic…

Systematic study of association of four GABAergic genes: glutamic acid decarboxylase 1 gene, glutamic acid decarboxylase 2 gene, GABA(B) receptor 1 gene and GABA(A) receptor subunit beta2 gene, with schizophrenia using a universal DNA microarray.

PubMed

Zhao, Xu; Qin, Shengying; Shi, Yongyong; Zhang, Aiping; Zhang, Jing; Bian, Li; Wan, Chunling; Feng, Guoyin; Gu, Niufan; Zhang, Guangqi; He, Guang; He, Lin

2007-07-01

Several studies have suggested the dysfunction of the GABAergic system as a risk factor in the pathogenesis of schizophrenia. In the present study, case-control association analysis was conducted in four GABAergic genes: two glutamic acid decarboxylase genes (GAD1 and GAD2), a GABA(A) receptor subunit beta2 gene (GABRB2) and a GABA(B) receptor 1 gene (GABBR1). Using a universal DNA microarray procedure we genotyped a total of 20 SNPs on the above four genes in a study involving 292 patients and 286 controls of Chinese descent. Statistically significant differences were observed in the allelic frequencies of the rs187269C/T polymorphism in the GABRB2 gene (P=0.0450, chi(2)=12.40, OR=1.65) and the -292A/C polymorphism in the GAD1 gene (P=0.0450, chi(2)=14.64 OR=1.77). In addition, using an electrophoretic mobility shift assay (EMSA), we discovered differences in the U251 nuclear protein binding to oligonucleotides representing the -292 SNP on the GAD1 gene, which suggests that the -292C allele has reduced transcription factor binding efficiency compared with the 292A allele. Using the multifactor-dimensionality reduction method (MDR), we found that the interactions among the rs187269C/T polymorphism in the GABRB2 gene, the -243A/G polymorphism in the GAD2 gene and the 27379C/T and 661C/T polymorphisms in the GAD1 gene revealed a significant association with schizophrenia (P<0.001). These findings suggest that the GABRB2 and GAD1 genes alone and the combined effects of the polymorphisms in the four GABAergic system genes may confer susceptibility to the development of schizophrenia in the Chinese population.

Alterations of the PPP2R1B gene located at 11q23 in human colorectal cancers

PubMed Central

Takagi, Y; Futamura, M; Yamaguchi, K; Aoki, S; Takahashi, T; Saji, S

2000-01-01

BACKGROUND/AIMS—In 1998 the PPP2R1B gene encoding the A subunit of the serine/threonine protein phosphatase was identified as a putative tumour suppressor gene in lung and colon cancer in the chromosome region 11q22-24. The aim of the present study was to determine the type of alterations in primary rectal cancers as well as colon cancers and the correlation between these alterations and clinicopathological data.
METHODS—Mutation analyses of the PPP2R1B gene sequence encoding the binding sites of the catalytic C subunit (Huntington elongation A subunit TOR (HEAT) repeats 11-15) and partial binding sites of the regulatory B subunit were carried out on cDNA samples from 30 primary colorectal cancer specimens and corresponding normal tissues using a combination of the polymerase chain reaction and subsequent direct DNA sequencing.
RESULTS—Five missense mutations producing amino acid substitutions were detected in the four colon cancer cases (13.3%; four of 30 colorectal cancers): 15glycine (GGT) to alanine (GCT) and 499leucine (TTA) to isoleucine (ATA) in the same case, and 498valine (GTG) to glutamic acid (GAG), 500valine (GTA) to glycine (GGA), and 365serine (TCT) to proline (CCT). Of these five mutations, three (60%) were located in HEAT repeat 13 and four (80%) showed T to other nucleotide substitutions. In addition, a normal polymorphism, 478leucine, was found. No correlation was found between these mutations and clinicopathological data.
CONCLUSION—Our results suggest that the PPP2R1B gene is one of the true targets at 11q23, and its inactivation is involved in the development of all types of colorectal cancers.


Keywords: PPP2R1B gene; colorectal cancer; tumour suppressor gene; protein phosphatase PMID:10896920

Common variants in the G protein beta3 subunit gene and thyroid disorders in a formerly iodine-deficient population.

PubMed

Völzke, Henry; Bornhorst, Alexa; Rimmbach, Christian; Petersenn, Holger; Geissler, Ingrid; Nauck, Matthias; Wallaschofski, Henri; Kroemer, Heyo K; Rosskopf, Dieter

2009-10-01

Heterotrimeric G proteins are key mediators of signals from membrane receptors-including the thyroid-stimulating hormone (TSH) receptor-to cellular effectors. Gain-of-function mutations in the TSH receptor and the Galpha(S) subunit occur frequently in hyperfunctioning thyroid nodules and differentiated thyroid carcinomas, whereby the T allele of a common polymorphism (825C>T, rs5443) in the G protein beta3 subunit gene (GNB3) is associated with increased G protein-mediated signal transduction and a complex phenotype. The aim of this study was to investigate whether this common polymorphism affects key parameters of thyroid function and morphology and influences the pathogenesis of thyroid diseases in the general population. The population-based cross-sectional Study of Health in Pomerania is a general health survey with focus on thyroid diseases in northeast Germany, a formerly iodine-deficient area. Data from 3428 subjects (1800 men and 1628 women) were analyzed for an association of the GNB3 genotype with TSH, free triiodothyronine and thyroxine levels, urine iodine and thiocyanate excretion, and thyroid ultrasound morphology including thyroid volume, presence of goiter, and thyroid nodules. There was no association between GNB3 genotype status and the functional or morphological thyroid parameters investigated, neither in crude analyses nor upon multivariable analyses including known confounders of thyroid disorders. Based on the data from this large population-based survey, we conclude that the GNB3 825C>T polymorphism does not affect key parameters of thyroid function and morphology in the general population of a formerly iodine-deficient area.

GABA-A receptor beta3 and alpha5 subunit gene cluster on chromosome 15q11-q13 and bipolar disorder: a genetic association study.

PubMed

Papadimitriou, G N; Dikeos, D G; Karadima, G; Avramopoulos, D; Daskalopoulou, E G; Stefanis, C N

2001-05-08

There is accumulated evidence that the genes coding for the receptor of gamma aminobutyric acid (GABA), the most important inhibitory neurotransmitter in the CNS, may be involved in the pathogenesis of affective disorders. In a previous study, we have found a genetic association between the GABA-A receptor alpha5 subunit gene locus (GABRA5) on chromosome 15q11-of 13 and bipolar affective disorder. The aim of the present study was to examine the same subjects to see if there exists a genetic association between bipolar affective disorder and the GABA receptor beta3 subunit gene (GABRB3), which is located within 100 kb from GABRA5. The sample consisted of 48 bipolar patients compared to 44 controls (blood donors). All subjects were Greek, unrelated, and personally interviewed. Diagnosis was based on DSM-IV and ICD-10 criteria. The marker used was a dinucleotide (CA) repeat polymorphism with 12 alleles 179 to 201 bp long; genotyping was successful in all patients and 43 controls. The distribution of GABRB3 genotypes among the controls did not deviate significantly from the Hardy-Weinberg equilibrium. No differences in allelic frequencies between bipolar patients and controls were found for GABRB3, while this locus and GABRA5 did not seem to be in significant linkage disequilibrium. In conclusion, the GABRB3 CA-repeat polymorphism we investigated does not present the observed association between bipolar affective illness and GABRA5. This could be due to higher mutation rate in the GABRB3 CA-repeat polymorphism, but it might also signify that GABRA5 is the gene actually associated with the disease. Copyright 2001 Wiley-Liss, Inc.

Genetic diversity and classification of Tibetan yak populations based on the mtDNA COIII gene.

PubMed

Song, Q Q; Chai, Z X; Xin, J W; Zhao, S J; Ji, Q M; Zhang, C F; Ma, Z J; Zhong, J C

2015-03-13

To determine the level of genetic diversity and phylogenetic relationships among Tibetan yak populations, the mitochondrial DNA cytochrome c oxidase subunit 3 (COIII) genes of 378 yak individuals from 16 populations were analyzed in this study. The results showed that the length of cytochrome c oxidase subunit 3 gene sequences was 781 bp, with nucleotide frequencies of 29.2, 29.4, 26.1, and 15.2% for T, C, A, and G, respectively. A total of 26 haplotypes were identified, with 69 polymorphic sites, including 11 parsimony-informative sites and 58 single-nucleotide polymorphism sites. No deletions/insertions were found in sequence comparison, indicating that nucleotide mutation types were transitions and transversions. Haplotype and nucleotide diversities were 0.562 and 0.00138, respectively, indicating a high level of genetic diversity in Tibetan yak populations. Phylogenetic relationship analysis indicated that Tibetan yak populations are divided into 2 groups.

The search for mutations in the gene for the beta subunit of the cGMP phosphodiesterase (PDEB) in patients with autosomal recessive retinitis pigmentosa

DOE Office of Scientific and Technical Information (OSTI.GOV)

Riess, O.; Weber, B.; Hayden, M.R.

1992-10-01

The finding of a mutation in the beta subunit of the cyclic GMP (cGMP) phosphodiesterase gene causing retinal degeneration in mice (the Pdeb gene) prompted a search for disease-causing mutations in the human phosphodiesterase gene (PDEB gene) in patients with retinitis pigmentosa. All 22 exons including 196 bp of the 5[prime] region of the PDEB gene have been assessed for mutations by using single-strand conformational polymorphism analysis in 14 patients from 13 unrelated families with autosomal recessive retinitis pigmentosa (ARRP). No disease-causing mutations were found in this group of affected individuals of seven different ancestries. However, a frequent intronic andmore » two exonic polymorphisms (Leu[sup 489][yields]Gln and Gly[sup 842][yields]Gly) were identified. Segregation analysis using these polymorphic sites excludes linkage of ARRP to the PDEB gene in a family with two affected children. 43 refs., 3 figs., 2 tabs.« less

Activity-dependent control of NMDA receptor subunit composition at hippocampal mossy fibre synapses.

PubMed

Carta, Mario; Srikumar, Bettadapura N; Gorlewicz, Adam; Rebola, Nelson; Mulle, Christophe

2018-02-15

CA3 pyramidal cells display input-specific differences in the subunit composition of synaptic NMDA receptors (NMDARs). Although at low density, GluN2B contributes significantly to NMDAR-mediated EPSCs at mossy fibre synapses. Long-term potentiation (LTP) of NMDARs triggers a modification in the subunit composition of synaptic NMDARs by insertion of GluN2B. GluN2B subunits are essential for the expression of LTP of NMDARs at mossy fibre synapses. Single neurons express NMDA receptors (NMDARs) with distinct subunit composition and biophysical properties that can be segregated in an input-specific manner. The dynamic control of the heterogeneous distribution of synaptic NMDARs is crucial to control input-dependent synaptic integration and plasticity. In hippocampal CA3 pyramidal cells from mice of both sexes, we found that mossy fibre (MF) synapses display a markedly lower proportion of GluN2B-containing NMDARs than associative/commissural synapses. The mechanism involved in such heterogeneous distribution of GluN2B subunits is not known. Here we show that long-term potentiation (LTP) of NMDARs, which is selectively expressed at MF-CA3 pyramidal cell synapses, triggers a modification in the subunit composition of synaptic NMDARs by insertion of GluN2B. This activity-dependent recruitment of GluN2B at mature MF-CA3 pyramidal cell synapses contrasts with the removal of GluN2B subunits at other glutamatergic synapses during development and in response to activity. Furthermore, although expressed at low levels, GluN2B is necessary for the expression of LTP of NMDARs at MF-CA3 pyramidal cell synapses. Altogether, we reveal a previously unknown activity-dependent regulation and function of GluN2B subunits that may contribute to the heterogeneous plasticity induction rules in CA3 pyramidal cells. © 2017 Centre Nationnal de la Recherche Scientifique. The Journal of Physiology © 2017 The Physiological Society.

Specific Roles of NMDA Receptor Subunits in Mental Disorders.

PubMed

Yamamoto, H; Hagino, Y; Kasai, S; Ikeda, K

2015-01-01

N-methyl-D-aspartate (NMDA) receptor plays important roles in learning and memory. NMDA receptors are a tetramer that consists of two glycine-binding subunits GluN1, two glutamate-binding subunits (i.e., GluN2A, GluN2B, GluN2C, and GluN2D), a combination of a GluN2 subunit and glycine-binding GluN3 subunit (i.e., GluN3A or GluN3B), or two GluN3 subunits. Recent studies revealed that the specific expression and distribution of each subunit are deeply involved in neural excitability, plasticity, and synaptic deficits. The present article summarizes reports on the dysfunction of NMDA receptors and responsible subunits in various neurological and psychiatric disorders, including schizophrenia, autoimmune-induced glutamatergic receptor dysfunction, mood disorders, and autism. A key role for the GluN2D subunit in NMDA receptor antagonist-induced psychosis has been recently revealed.

β Subunits Functionally Differentiate Human Kv4.3 Potassium Channel Splice Variants

PubMed Central

Abbott, Geoffrey W.

2017-01-01

The human ventricular cardiomyocyte transient outward K+ current (Ito) mediates the initial phase of myocyte repolarization and its disruption is implicated in Brugada Syndrome and heart failure (HF). Human cardiac Ito is generated primarily by two Kv4.3 splice variants (Kv4.3L and Kv4.3S, diverging only by a C-terminal, S6-proximal, 19-residue stretch unique to Kv4.3L), which are differentially remodeled in HF, but considered functionally alike at baseline. Kv4.3 is regulated in human heart by β subunits including KChIP2b and KCNEs, but their effects were previously assumed to be Kv4.3 isoform-independent. Here, this assumption was tested experimentally using two-electrode voltage-clamp analysis of human subunits co-expressed in Xenopus laevis oocytes. Unexpectedly, Kv4.3L-KChIP2b channels exhibited up to 8-fold lower current augmentation, 40% slower inactivation, and 5 mV-shifted steady-state inactivation compared to Kv4.3S-KChIP2b. A synthetic peptide mimicking the 19-residue stretch diminished these differences, reinforcing the importance of this segment in mediating Kv4.3 regulation by KChIP2b. KCNE subunits induced further functional divergence, including a 7-fold increase in Kv4.3S-KCNE4-KChIP2b current compared to Kv4.3L-KCNE4-KChIP2b. The discovery of β-subunit-dependent functional divergence in human Kv4.3 splice variants suggests a C-terminal signaling hub is crucial to governing β-subunit effects upon Kv4.3, and demonstrates the potential significance of differential Kv4.3 gene-splicing and β subunit expression in myocyte physiology and pathobiology. PMID:28228734

β Subunits Functionally Differentiate Human Kv4.3 Potassium Channel Splice Variants.

PubMed

Abbott, Geoffrey W

2017-01-01

The human ventricular cardiomyocyte transient outward K + current ( I to ) mediates the initial phase of myocyte repolarization and its disruption is implicated in Brugada Syndrome and heart failure (HF). Human cardiac I to is generated primarily by two Kv4.3 splice variants (Kv4.3L and Kv4.3S, diverging only by a C-terminal, S6-proximal, 19-residue stretch unique to Kv4.3L), which are differentially remodeled in HF, but considered functionally alike at baseline. Kv4.3 is regulated in human heart by β subunits including KChIP2b and KCNEs, but their effects were previously assumed to be Kv4.3 isoform-independent. Here, this assumption was tested experimentally using two-electrode voltage-clamp analysis of human subunits co-expressed in Xenopus laevis oocytes. Unexpectedly, Kv4.3L-KChIP2b channels exhibited up to 8-fold lower current augmentation, 40% slower inactivation, and 5 mV-shifted steady-state inactivation compared to Kv4.3S-KChIP2b. A synthetic peptide mimicking the 19-residue stretch diminished these differences, reinforcing the importance of this segment in mediating Kv4.3 regulation by KChIP2b. KCNE subunits induced further functional divergence, including a 7-fold increase in Kv4.3S-KCNE4-KChIP2b current compared to Kv4.3L-KCNE4-KChIP2b. The discovery of β-subunit-dependent functional divergence in human Kv4.3 splice variants suggests a C-terminal signaling hub is crucial to governing β-subunit effects upon Kv4.3, and demonstrates the potential significance of differential Kv4.3 gene-splicing and β subunit expression in myocyte physiology and pathobiology.

Coexpression of the KCNA3B gene product with Kv1.5 leads to a novel A-type potassium channel.

PubMed

Leicher, T; Bähring, R; Isbrandt, D; Pongs, O

1998-12-25

Shaker-related voltage-gated potassium (Kv) channels may be heterooligomers consisting of membrane-integral alpha-subunits associated with auxiliary cytoplasmic beta-subunits. In this study we have cloned the human Kvbeta3.1 subunit and the corresponding KCNA3B gene. Identification of sequence-tagged sites in the gene mapped KCNA3B to band p13.1 of human chromosome 17. Comparison of the KCNA1B, KCNA2B, and KCNA3B gene structures showed that the three Kvbeta genes have very disparate lengths varying from >/=350 kb (KCNA1B) to approximately 7 kb (KCNA3B). Yet, the exon patterns of the three genes, which code for the seven known mammalian Kvbeta subunits, are very similar. The Kvbeta1 and Kvbeta2 splice variants are generated by alternative use of 5'-exons. Mouse Kvbeta4, a potential splice variant of Kvbeta3, is a read-through product where the open reading frame starts within the sequence intervening between Kvbeta3 exons 7 and 8. The human KCNA3B sequence does not contain a mouse Kvbeta4-like open reading frame. Human Kvbeta3 mRNA is specifically expressed in the brain, where it is predominantly detected in the cerebellum. The heterologous coexpression of human Kv1.5 and Kvbeta3.1 subunits in Chinese hamster ovary cells yielded a novel Kv channel mediating very fast inactivating (A-type) outward currents upon depolarization. Thus, the expression of Kvbeta3.1 subunits potentially extends the possibilities to express diverse A-type Kv channels in the human brain.

Epistatic interaction between FCRL3 and NFκB1 genes in Spanish patients with rheumatoid arthritis

PubMed Central

Martínez, A; Sánchez, E; Valdivia, A; Orozco, G; López‐Nevot, M A; Pascual‐Salcedo, D; Balsa, A; Fernández‐Gutiérrez, B; de la Concha, E G; García‐Sánchez, A; Koeleman, B P C; Urcelay, E; Martín, J

2006-01-01

Background A Japanese study has described a strong association between rheumatoid arthritis and several polymorphisms located in the Fc receptor‐like 3 (FCRL3) gene, a member of a family of genes related to Fc receptors located on chromosome 1q21–23. Objectives To evaluate the association between rheumatoid arthritis and FCLR3 polymorphisms in a large cohort of Caucasian patients with rheumatoid arthritis and healthy controls of Spanish origin. Owing to the described functional link between the FCRL3 polymorphisms and the transcription factor nuclear factor κB (NFκB), a functional polymorphism located in the NFκB1 gene was included. Methods 734 patients with rheumatoid arthritis from Madrid and Granada, Spain, were included in the study, along with 736 healthy controls. Polymorphisms in the FCRL3 gene were studied by TaqMan technology. The −94ins/delATTG NFκB1 promoter polymorphism was analysed by fragment analysis after polymerase chain reaction with labelled primers. Genotypes were compared using 3×2 contingency tables and χ2 values. Results No overall differences were found in any of the FCRL3 polymorphisms and in the NFκB1 promoter polymorphism when patients were compared with controls. However, when stratified according to NFκB1 genotypes, a susceptibility effect of FCRL3 polymorphisms was observed in patients who were heterozygotes for NFκB1 (pc = 0.003). Conclusions The FCRL3 polymorphisms associated with rheumatoid arthritis in a Japanese population are not associated per se with rheumatoid arthritis in a Spanish population. A genetic interaction was found between NFκB1 and FCRL3 in Spanish patients with rheumatoid arthritis. These findings may provide a general rationale for divergent genetic association results in different populations. PMID:16476711

Polymorphism in glutamate cysteine ligase catalytic subunit (GCLC) is associated with sulfamethoxazole-induced hypersensitivity in HIV/AIDS patients

PubMed Central

2012-01-01

Background Sulfamethoxazole (SMX) is a commonly used antibiotic for prevention of infectious diseases associated with HIV/AIDS and immune-compromised states. SMX-induced hypersensitivity is an idiosyncratic cutaneous drug reaction with genetic components. Here, we tested association of candidate genes involved in SMX bioactivation and antioxidant defense with SMX-induced hypersensitivity. Results Seventy seven single nucleotide polymorphisms (SNPs) from 14 candidate genes were genotyped and assessed for association with SMX-induced hypersensitivity, in a cohort of 171 HIV/AIDS patients. SNP rs761142 T > G, in glutamate cysteine ligase catalytic subunit (GCLC), was significantly associated with SMX-induced hypersensitivity, with an adjusted p value of 0.045. This result was replicated in a second cohort of 249 patients (p = 0.025). In the combined cohort, heterozygous and homozygous carriers of the minor G allele were at increased risk of developing hypersensitivity (GT vs TT, odds ratio = 2.2, 95% CL 1.4-3.7, p = 0.0014; GG vs TT, odds ratio = 3.3, 95% CL 1.6 – 6.8, p = 0.0010). Each minor allele copy increased risk of developing hypersensitivity 1.9 fold (95% CL 1.4 – 2.6, p = 0.00012). Moreover, in 91 human livers and 84 B-lymphocytes samples, SNP rs761142 homozygous G allele carriers expressed significantly less GCLC mRNA than homozygous TT carriers (p < 0.05). Conclusions rs761142 in GCLC was found to be associated with reduced GCLC mRNA expression and with SMX-induced hypersensitivity in HIV/AIDS patients. Catalyzing a critical step in glutathione biosynthesis, GCLC may play a broad role in idiosyncratic drug reactions. PMID:22824134

XAS Characterization of the Zn Site of Non-structural Protein 3 (NS3) from Hepatitis C Virus

NASA Astrophysics Data System (ADS)

Ascone, I.; Nobili, G.; Benfatto, M.; Congiu-Castellano, A.

2007-02-01

XANES spectra of non structural protein 3 (NS3) have been calculated using 4 Zn coordination models from three crystallographic structures in the Protein Data Base (PDB): 1DY9, subunit B, 1CU1 subunit A and B, and 1JXP subunit B. Results indicate that XANES is an appropriate tool to distinguish among them. Experimental XANES spectra have been simulated refining crystallographic data. The model obtained by XAS is compared with the PDB models.

[Analysis of diversity of Russian and Ukrainian bread wheat (Triticum aestivum L.) cultivars for high-molecular-weight glutenin subunits].

PubMed

Dobrotvorskaia, T V; Martynov, S P

2011-07-01

The allelic diversity of high-moleculat-weght glutenin subunits (H WIGS) in Russian and Ukrainian bread wheat cultivars was analyzed. The diversity of spring wheat cultivars for alleles of the Glu-1 loci is characterized by medium values of the polymorphism index (polymorphism information content, PlC), and in winter wheats it varies from high at the Glu-A1 locus to low at the Glu-D1 locus. The spring and winter cultivars differ significantly in the frequencies of alleles of the glutenin loci. The combination of the Glu-A1b, Glu-B1c, and Glu-D1a alleles prevails among the spring cultivars, and the combination of the Glu-A1a, Glu-B1c, and Glu-D1d alleles prevails among the winter cultivars. The distribution of the Glu-1 alleles significantly depends on the moisture and heat supply in the region of origin of the cultivars. Drought resistance is associated with the Glu-D1a allele in the spring wheat and with the Glu-B1b allele in the winter wheat. The sources of the Glu-1 alleles were identified in the spring and wheat cultivars. The analysis of independence of the distribution of the spring and winter cultivars by the market classes and by the alleles of the HMWGS loci showed a highly significant association of the alleles of three Glu-1 loci with the market classes in foreign cultivars and independence or a weak association in the Russian and Ukrainian cultivars. This seems to be due to the absence of a statistically substantiated system of classification of the domestic cultivars on the basis of their quality.

Mitochondrial ATPase Subunit 6 and Cytochrome B Gene Variations in Obese Turkish Children

PubMed Central

Demir, Durkadın; Türkkahraman, Doğa; Samur, Anıl Aktaş; Lüleci, Güven; Akçurin, Sema; M. Alper, Özgül

2014-01-01

Objective: Due to the importance of energy metabolism in mitochondria, mitochondrial genome variations are evaluated in energy-related diseases such as obesity. To date, several nuclear genes were found to be related to obesity. Our aim in this study was to investigate the presence of polymorphisms in mitochondrial ATPase subunit 6 (mt-ATP6) and cytochrome b (mt-CytB) genes that may be associated with childhood obesity. Methods: The mt-ATP6 and mt-CytB genes were amplified and entirely sequenced in a series of 100 obese and in an equal number of healthy Turkish children aged between 6-14 years. Results: A total of 118 synonymous and nonsynonymous variations were detected in the obese and control groups. Only two previously reported synonymous substitutions (mt.8614T>C and mt.8994G>A) in the mt-ATP6 gene were found to be significantly higher in the obese group compared to the control group (p<0.05). In the mt-ATP6 gene, one novel nonsynonymous substitution (mt.8726C>T) and one novel synonymous substitution (mt.9108A>T) were found. In the mt-CytB gene, one nonsynonymous substitution (mt.14880T>C) and two synonymous substitutions (mt.14891C>T and mt.15091C>T) were novel substitutions. Conclusion: Two synonymous substitutions (mt.8614T>C and mt.8994G>A) in the mt-ATP6 gene may be associated with childhood obesity. Our study provides the first data about mitochondrial genome variations in a Turkish obese population and also the first in obese children. More cases should be screened in obese groups in order to understand the effects of mitochondrial polymorphisms in the development of obesity. PMID:25541891

The 2.3 {angstrom} crystal structure of cholera toxin B subunit pentamer: Choleragenoid

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Rong-Guang; Westbrook, M.L.; Maulik, P.R.

1996-02-01

Cholera toxin, a heterohexameric AB{sub 5} enterotoxin released by Vibrio cholera, induces a profuse secretory diarrhea in susceptible hosts. Choleragenoid, the B subunit pentamer of cholera toxin, directs the enzymatic A subunit to its target by binding to GM{sub 1} gangliosides exposed on the luminal surface of intestinal epithelial cells. We have solved the crystal structure of choleragenoid at 2.3 {Angstrom} resolution by combining single isomorphous replacement with non-crystallographic symmetry averaging. The structure of the B subunits, and their pentameric arrangement, closely resembles that reported for the intact holotoxin (choleragen), the heat-labile enterotoxin from E. coli, and for a choleragenoid-GM{submore » 1} pentasaccharide complex. In the absence of the A subunit the central cavity of the B pentamer is a highly solvated channel. The binding of the A subunit or the receptor pentasaccharide to choleragenoid has only a modest effect on the local stereochemistry and does not perceptibly alter the subunit interface.« less

Association of the GRIN2B rs2284411 polymorphism with methylphenidate response in attention-deficit/hyperactivity disorder.

PubMed

Kim, Johanna I; Kim, Jae-Won; Park, Jong-Eun; Park, Subin; Hong, Soon-Beom; Han, Doug Hyun; Cheong, Jae Hoon; Choi, Jae-Won; Lee, Sumin; Kim, Bung-Nyun

2017-08-01

We investigated the possible association between two NMDA subunit gene polymorphisms (GRIN2B rs2284411 and GRIN2A rs2229193) and treatment response to methylphenidate (MPH) in attention-deficit/hyperactivity disorder (ADHD). A total of 75 ADHD patients aged 6-17 years underwent 6 months of MPH administration. Treatment response was defined by changes in scores of the ADHD-IV Rating Scale (ADHD-RS), clinician-rated Clinical Global Impression-Improvement (CGI-I), and Continuous Performance Test (CPT). The association of the GRIN2B and GRIN2A polymorphisms with treatment response was analyzed using logistic regression analyses. The GRIN2B rs2284411 C/C genotype showed significantly better treatment response as assessed by ADHD-RS inattention ( p=0.009) and CGI-I scores ( p=0.009), and there was a nominally significant association in regard to ADHD-RS hyperactivity-impulsivity ( p=0.028) and total ( p=0.023) scores, after adjusting for age, sex, IQ, baseline Clinical Global Impression-Severity (CGI-S) score, baseline ADHD-RS total score, and final MPH dose. The GRIN2B C/C genotype also showed greater improvement at the CPT response time variability ( p<0.001). The GRIN2A G/G genotype was associated with a greater improvement in commission errors of the CPT compared to the G/A genotype ( p=0.001). The results suggest that the GRIN2B rs2284411 genotype may be an important predictor of MPH response in ADHD.

Radial symmetry in a chimeric glutamate receptor pore

NASA Astrophysics Data System (ADS)

Wilding, Timothy J.; Lopez, Melany N.; Huettner, James E.

2014-02-01

Ionotropic glutamate receptors comprise two conformationally different A/C and B/D subunit pairs. Closed channels exhibit fourfold radial symmetry in the transmembrane domain (TMD) but transition to twofold dimer-of-dimers symmetry for extracellular ligand binding and N-terminal domains. Here, to evaluate symmetry in open pores we analysed interaction between the Q/R editing site near the pore loop apex and the transmembrane M3 helix of kainate receptor subunit GluK2. Chimeric subunits that combined the GluK2 TMD with extracellular segments from NMDA receptors, which are obligate heteromers, yielded channels made up of A/C and B/D subunit pairs with distinct substitutions along M3 and/or Q/R site editing status, in an otherwise identical homotetrameric TMD. Our results indicate that Q/R site interaction with M3 occurs within individual subunits and is essentially the same for both A/C and B/D subunit conformations, suggesting that fourfold pore symmetry persists in the open state.

Genetic divergence for high-molecular weight glutenin subunits (HMW-GS) in indigenous landraces and commercial cultivars of bread wheat of Pakistan.

PubMed

Yasmeen, F; Khurshid, H; Ghafoor, A

2015-05-11

Wheat flour quality is an important consideration in the breeding and development of new cultivars. A strong association between high-molecular weight glutenin subunits (HMW-GS) and bread making quality has resulted in the widespread utilization of HMW-GS in wheat breeding. In this study, we analyzed 242 lines of wheat, including landraces from the provinces of Punjab and Baluchistan, as well as the commercial varieties of Pakistan, to determine allelic variation in the Glu-A1, Glu-B1, and Glu-D1 loci encoding HMW-GS. Higher genetic diversity was observed for HMW-GS in landraces from Baluchistan, followed by landraces collected from Punjab and then commercial varieties. Rare and uncommon subunits were observed in Glu-B1, whereas Glu-A1 was less polymorphic. However, Glu-B1 was the highest contributor to overall diversity (78%), with a total of 31 rare alleles, followed by Glu-D1 (20%) with the high quality 5+10 allele and other variants. Commercial cultivars possessed favorable alleles, potentially from indirect selection for wheat flour quality by the breeders; however, this indirect selection has decreased the pedigree base of commercial cultivars. The allelic combinations, including 2*, 5+10, and 17+18, showing high quality scores were frequent among landraces, indicating their usefulness in future crop improvement and breeding programs.

B56δ-related protein phosphatase 2A dysfunction identified in patients with intellectual disability

PubMed Central

Houge, Gunnar; Haesen, Dorien; Vissers, Lisenka E.L.M.; Mehta, Sarju; Parker, Michael J.; Wright, Michael; Vogt, Julie; McKee, Shane; Tolmie, John L.; Cordeiro, Nuno; Kleefstra, Tjitske; Willemsen, Marjolein H.; Reijnders, Margot R.F.; Berland, Siren; Hayman, Eli; Lahat, Eli; Brilstra, Eva H.; van Gassen, Koen L.I.; Zonneveld-Huijssoon, Evelien; de Bie, Charlotte I.; Hoischen, Alexander; Eichler, Evan E.; Holdhus, Rita; Steen, Vidar M.; Døskeland, Stein Ove; Hurles, Matthew E.; FitzPatrick, David R.; Janssens, Veerle

2015-01-01

Here we report inherited dysregulation of protein phosphatase activity as a cause of intellectual disability (ID). De novo missense mutations in 2 subunits of serine/threonine (Ser/Thr) protein phosphatase 2A (PP2A) were identified in 16 individuals with mild to severe ID, long-lasting hypotonia, epileptic susceptibility, frontal bossing, mild hypertelorism, and downslanting palpebral fissures. PP2A comprises catalytic (C), scaffolding (A), and regulatory (B) subunits that determine subcellular anchoring, substrate specificity, and physiological function. Ten patients had mutations within a highly conserved acidic loop of the PPP2R5D-encoded B56δ regulatory subunit, with the same E198K mutation present in 6 individuals. Five patients had mutations in the PPP2R1A-encoded scaffolding Aα subunit, with the same R182W mutation in 3 individuals. Some Aα cases presented with large ventricles, causing macrocephaly and hydrocephalus suspicion, and all cases exhibited partial or complete corpus callosum agenesis. Functional evaluation revealed that mutant A and B subunits were stable and uncoupled from phosphatase activity. Mutant B56δ was A and C binding–deficient, while mutant Aα subunits bound B56δ well but were unable to bind C or bound a catalytically impaired C, suggesting a dominant-negative effect where mutant subunits hinder dephosphorylation of B56δ-anchored substrates. Moreover, mutant subunit overexpression resulted in hyperphosphorylation of GSK3β, a B56δ-regulated substrate. This effect was in line with clinical observations, supporting a correlation between the ID degree and biochemical disturbance. PMID:26168268

Understanding the mechanisms of ATPase beta family genes for cellular thermotolerance in crossbred bulls

NASA Astrophysics Data System (ADS)

Deb, Rajib; Sajjanar, Basavaraj; Singh, Umesh; Alex, Rani; Raja, T. V.; Alyethodi, Rafeeque R.; Kumar, Sushil; Sengar, Gyanendra; Sharma, Sheetal; Singh, Rani; Prakash, B.

2015-12-01

Na+/K+-ATPase is an integral membrane protein composed of a large catalytic subunit (alpha), a smaller glycoprotein subunit (beta), and gamma subunit. The beta subunit is essential for ion recognition as well as maintenance of the membrane integrity. Present study was aimed to analyze the expression pattern of ATPase beta subunit genes (ATPase B1, ATPase B2, and ATPase B3) among the crossbred bulls under different ambient temperatures (20-44 °C). The present study was also aimed to look into the relationship of HSP70 with the ATPase beta family genes. Our results demonstrated that among beta family genes, transcript abundance of ATPase B1 and ATPase B2 is significantly ( P < 0.05) higher during the thermal stress. Pearson correlation coefficient analysis revealed that the expression of ATPase Β1, ATPase B2, and ATPase B3 is highly correlated ( P < 0.01) with HSP70, representing that the change in the expression pattern of these genes is positive and synergistic. These may provide a foundation for understanding the mechanisms of ATPase beta family genes for cellular thermotolerance in cattle.

The NMDA receptor NR2A subunit regulates proliferation of MKN45 human gastric cancer cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Watanabe, Kanako; Department of Anesthesiology, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya 663-8501; Kanno, Takeshi

2008-03-07

The present study investigated proliferation of MKN28 and MKN45 human gastric cancer cells regulated by the N-methyl-D-aspartate (NMDA) receptor subunit. The NMDA receptor antagonist DL-2-amino-5-phosphonovaleric acid (AP5) inhibited proliferation of MKN45 cells, but not MKN28 cells. Of the NMDA subunits such as NR1, NR2 (2A, 2B, 2C, and 2D), and NR3 (3A and 3B), all the NMDA subunit mRNAs except for the NR2B subunit mRNA were expressed in both MKN28 and MKN45 cells. MKN45 cells were characterized by higher expression of the NR2A subunit mRNA and lower expression of the NR1 subunit mRNA, but MKN28 otherwise by higher expression ofmore » the NR1 subunit mRNA and lower expression of the NR2A subunit mRNA. MKN45 cell proliferation was also inhibited by silencing the NR2A subunit-targeted gene. For MKN45 cells, AP5 or knocking-down the NR2A subunit increased the proportion of cells in the G{sub 1} phase of cell cycling and decreased the proportion in the S/G{sub 2} phase. The results of the present study, thus, suggest that blockage of NMDA receptors including the NR2A subunit suppresses MKN45 cell proliferation due to cell cycle arrest at the G{sub 1} phase; in other words, the NR2A subunit promotes MKN45 cell proliferation by accelerating cell cycling.« less

Monoclonal antibodies to molluskan hemocyanin from Concholepas concholepas demonstrate common and specific epitopes among subunits.

PubMed

Oliva, Harold; Moltedo, Bruno; De Ioannes, Pablo; Faunes, Fernando; De Ioannes, Alfredo E; Becker, María Inés

2002-10-01

We studied the reactivity of mouse monoclonal antibodies (MAbs) against the hemocyanin from the Chilean marine gastropod Concholepas concholepas (CCH). This protein has been successfully used as a carrier to produce antibodies to haptens and peptides. All MAbs (13) belonging to IgG subclass exhibit dissociation constants (K(d)) from 1 x 10(-7) M to 1 x 10(-9) M. MAbs were characterized by enzyme-linked immunosorbant assay (ELISA) using CCH treated with different procedures, including dissociation into CCH-A and CCH-B subunits, Western blot, enzymatic digestion, chemical deglycosylation, and thermal denaturation. MAbs were classified into three categories, according to subunit specificity by ELISA. The epitope distribution shows that CCH subunits display common epitopes (group I, 5 MAbs, 1H5, 2A8, 3A5, 3B3, and 3E3), as well as specific epitopes for CCH-A subunits (group II, 3 MAbs, 1B8, 4D8, and 8E5) and for CCH-B subunits (group III, 5 MAbs, 1A4, 1E4, 2H10, 3B7, and 7B4). The results can be summarized as follows: (1). six antibodies react with thermal denatured CCH, suggesting that they recognize linear epitopes, whereas seven recognize conformational epitopes; (2). oxidation of carbohydrate moieties does not affect the binding of the MAbs; (3). enzymatic digestion of CCH decreases the reactivity of all antibodies irrespective of the protease used (elastase or trypsin); (4). bringing together the above data, in addition to epitopic complementarity analysis, we identified 12 different epitopes on the CCH molecule recognized by these MAbs. The anti-CCH MAbs presented here can be useful tools to understand the subunit organization of the CCH and its complex structure, which can explain its immunogenic and immunostimulating properties in mammals.

Arabidopsis thaliana GYRB3 Does Not Encode a DNA Gyrase Subunit

PubMed Central

Evans-Roberts, Katherine M.; Breuer, Christian; Wall, Melisa K.; Sugimoto-Shirasu, Keiko; Maxwell, Anthony

2010-01-01

Background DNA topoisomerases are enzymes that control the topology of DNA in all cells. DNA gyrase is unique among the topoisomerases in that it is the only enzyme that can actively supercoil DNA using the free energy of ATP hydrolysis. Until recently gyrase was thought to be unique to bacteria, but has now been discovered in plants. The genome of the model plant, Arabidopsis thaliana, is predicted to encode four gyrase subunits: AtGyrA, AtGyrB1, AtGyrB2 and AtGyrB3. Methodology/Principal Findings We found, contrary to previous data, that AtGyrB3 is not essential to the survival of A. thaliana. Bioinformatic analysis suggests AtGyrB3 is considerably shorter than other gyrase B subunits, lacking part of the ATPase domain and other key motifs found in all type II topoisomerases; but it does contain a putative DNA-binding domain. Partially purified AtGyrB3 cannot bind E. coli GyrA or support supercoiling. AtGyrB3 cannot complement an E. coli gyrB temperature-sensitive strain, whereas AtGyrB2 can. Yeast two-hybrid analysis suggests that AtGyrB3 cannot bind to AtGyrA or form a dimer. Conclusions/Significance These data strongly suggest that AtGyrB3 is not a gyrase subunit but has another unknown function. One possibility is that it is a nuclear protein with a role in meiosis in pollen. PMID:20360860

Arabidopsis thaliana GYRB3 does not encode a DNA gyrase subunit.

PubMed

Evans-Roberts, Katherine M; Breuer, Christian; Wall, Melisa K; Sugimoto-Shirasu, Keiko; Maxwell, Anthony

2010-03-26

DNA topoisomerases are enzymes that control the topology of DNA in all cells. DNA gyrase is unique among the topoisomerases in that it is the only enzyme that can actively supercoil DNA using the free energy of ATP hydrolysis. Until recently gyrase was thought to be unique to bacteria, but has now been discovered in plants. The genome of the model plant, Arabidopsis thaliana, is predicted to encode four gyrase subunits: AtGyrA, AtGyrB1, AtGyrB2 and AtGyrB3. We found, contrary to previous data, that AtGyrB3 is not essential to the survival of A. thaliana. Bioinformatic analysis suggests AtGyrB3 is considerably shorter than other gyrase B subunits, lacking part of the ATPase domain and other key motifs found in all type II topoisomerases; but it does contain a putative DNA-binding domain. Partially purified AtGyrB3 cannot bind E. coli GyrA or support supercoiling. AtGyrB3 cannot complement an E. coli gyrB temperature-sensitive strain, whereas AtGyrB2 can. Yeast two-hybrid analysis suggests that AtGyrB3 cannot bind to AtGyrA or form a dimer. These data strongly suggest that AtGyrB3 is not a gyrase subunit but has another unknown function. One possibility is that it is a nuclear protein with a role in meiosis in pollen.

Localization and function of the Kv3.1b subunit in the rat medulla oblongata: focus on the nucleus tractus solitarii

PubMed Central

Dallas, Mark L; Atkinson, Lucy; Milligan, Carol J; Morris, Neil P; Lewis, David I; Deuchars, Susan A; Deuchars, Jim

2005-01-01

The voltage-gated potassium channel subunit Kv3.1 confers fast firing characteristics to neurones. Kv3.1b subunit immunoreactivity (Kv3.1b-IR) was widespread throughout the medulla oblongata, with labelled neurones in the gracile, cuneate and spinal trigeminal nuclei. In the nucleus of the solitary tract (NTS), Kv3.1b-IR neurones were predominantly located close to the tractus solitarius (TS) and could be GABAergic or glutamatergic. Ultrastructurally, Kv3.1b-IR was detected in NTS terminals, some of which were vagal afferents. Whole-cell current-clamp recordings from neurones near the TS revealed electrophysiological characteristics consistent with the presence of Kv3.1b subunits: short duration action potentials (4.2 ± 1.4 ms) and high firing frequencies (68.9 ± 5.3 Hz), both sensitive to application of TEA (0.5 mm) and 4-aminopyridine (4-AP; 30 μm). Intracellular dialysis of an anti-Kv3.1b antibody mimicked and occluded the effects of TEA and 4-AP in NTS and dorsal column nuclei neurones, but not in dorsal vagal nucleus or cerebellar Purkinje cells (which express other Kv3 subunits, but not Kv3.1b). Voltage-clamp recordings from outside-out patches from NTS neurones revealed an outward K+ current with the basic characteristics of that carried by Kv3 channels. In NTS neurones, electrical stimulation of the TS evoked EPSPs and IPSPs, and TEA and 4-AP increased the average amplitude and decreased the paired pulse ratio, consistent with a presynaptic site of action. Synaptic inputs evoked by stimulation of a region lacking Kv3.1b-IR neurones were not affected, correlating the presence of Kv3.1b in the TS with the pharmacological effects. PMID:15528247

Theory of polymorphism in bacterial flagella

NASA Astrophysics Data System (ADS)

Powers, Thomas

2004-03-01

Escherichia coli and Salmonella swim using several flagella, each of which consists of a rotary motor, a universal joint known as the hook, and a helical filament which acts a propeller. The filament is normally left-handed in the absence of external stress, but undergoes mechanical phase transitions to other helical states ("polymorphs") in response to external torque. The filament is made of identical flagellin protein subunits which are organized into eleven protofilaments which wind around the filament. We develop an effective theory in which the flagellin subunits and their connections along the protofilaments are modelled with a double-well potential. A helical spring represents the other connections of the subunits, and introduces a twist-stretch coupling and an element of frustration in our model. We solve for the ground states and the phase diagram for filament shapes.

[Prevalence of dyslipidemia in middle-aged adults with NOS3 gene polymorphism and low cardiorespiratory fitness].

PubMed

Malagrino, Pamella A; Sponton, Carlos H G; Esposti, Rodrigo D; Franco-Penteado, Carla F; Fernandes, Romulo A; Bezerra, Marcos André C; Albuquerque, Dulcinéia M; Rodovalho, Cynara M; Bacci, Maurício; Zanesco, Angelina

2013-02-01

To evaluate the influence of the interaction between endothelial nitric oxide synthase gene (NOS3) polymorphisms at positions -786T>C, Glu298Asp and intron 4b/a, and cardiorespiratory fitness on plasma nitrite/nitrate levels, blood pressure, lipid profile, and prevalence of cardiometabolic disorders. Ninety-two volunteers were genotyped for NOS3 polymorphisms at positions (-786T>C and Glu298Asp) and (intron 4b/a) and divided according to the genotype: non-polymorphic (NP) and polymorphic (P). After that, they were subdivided according to the cardiorespiratory fitness associated with genotype: high (HNP and HP) and low (LNP and LP). The subjects with polymorphism for the interactions at positions Glu298Asp + intron 4b/a, and Glu298Asp+-786T>C showed the highest values in total cholesterol, as well as dyslipidemia. Our findings show that NOS3 gene polymorphisms at positions -786T>C, Glu298Asp, and intron 4b/a exert negative effects on the lipid profile compared with those who do not carry polymorphisms.

Genetic and morphologic differentiation of Bolbophorus confusus and B. levantinus (Digenea: Diplostomatidae), based on rDNA SSU polymorphism and SEM.

PubMed

Dzikowski, R; Levy, M G; Poore, M F; Flowers, J R; Paperna, I

2003-12-29

Metacercariae of Bolbophorus species are serious pathogens of farmed fish. Molecular diagnostic tools, capable of identifying and differentiating these parasites, may assist in the development of rationale control strategies. The rDNA 18S (small sub-unit: SSU) genes of adult B. confusus and B. levantinus obtained from a pelican, Pelecanus onocrotalus, and a night heron, Nycticorax nycticorax, respectively, were amplified, sequenced, and aligned. Based on this alignment, we developed a genetic differentiation assay between B. confusus and B. levantinus. These 2 species were compared genetically with the North American species B. damnificus and Bolbophorus sp. ('Type 2'). The relationship between species is outlined and discussed. In addition to the molecular study, specimens of B. confusus and B. levantinus were compared morphologically, using scanning electron microscopy. Morphologic analysis revealed interspecific differences in details of the holdfast organ and the position of the acetabulum.

The role of polymorphisms in the spliced leader addition domain in determining promoter activity in Brugia malayi.

PubMed

Bailey, Michelle; Chauhan, Chitra; Liu, Canhui; Unnasch, Thomas R

2011-03-01

Previous studies of Brugia malayi promoters have suggested that they are unusual in that they lack the CAAT or TATAA boxes that are often emblematic of eucaryotic core promoter domains. Instead, the region surrounding the spliced leader (SL) addition site appears to function as the core promoter domain in B. malayi. To test the hypothesis that polymorphisms in this SL addition domain are important determinants of promoter activity, a series of domain swap mutants were prepared replacing the SL addition domain of the B. malayi 13kDa large subunit ribosomal protein (BmRPL13) with those of other ribosomal protein (RP) promoters exhibiting a wide range of activities. These constructs were then tested for promoter activity in a homologous transient transfection system. On average, polymorphisms in the SL addition domain were found to be responsible for 80% of the variation in promoter activity exhibited by the RP promoters tested. Essentially all of this effect could be attributable to polymorphisms in the 10nt located directly upstream of the SL addition site. A comparison of the sequence of this domain to the promoter activity exhibited by the domain swap mutants suggested that promoter activity was related to the number of T residues present in the coding strand of the upstream domain. Confirming this, mutation of the upstream domain of the promoter of the BmRPS4 gene to a homogeneous stretch of 10 T residues resulted in a significant increase in promoter activity. Copyright © 2010 Elsevier B.V. All rights reserved.

Smoking cessation pharmacogenetics: analysis of varenicline and bupropion in placebo-controlled clinical trials.

PubMed

King, David P; Paciga, Sara; Pickering, Eve; Benowitz, Neal L; Bierut, Laura J; Conti, David V; Kaprio, Jaakko; Lerman, Caryn; Park, Peter W

2012-02-01

Despite effective therapies for smoking cessation, most smokers find quitting difficult and most successful quitters relapse. Considerable evidence supports a genetic risk for nicotine dependence; however, less is known about the pharmacogenetics of smoking cessation. In the first pharmacogenetic investigation of the efficacy of varenicline and bupropion, we examined whether genes important in the pharmacodynamics and pharmacokinetics of these drugs and nicotine predict medication efficacy and adverse events. Subjects participated in randomized, double-blind, placebo-controlled smoking cessation clinical trials, comparing varenicline, a nicotinic acetylcholine receptor (nAChR) partial agonist, with bupropion, a norepinephrine/dopamine reuptake inhibitor, and placebo. Primary analysis included 1175 smokers of European ancestry, and 785 single nucleotide polymorphisms from 24 genes, representing 254 linkage disequilibrium (LD) bins (genes included nAChR subunits, additional varenicline-specific genes, and genes involved in nicotine or bupropion metabolism). For varenicline, continuous abstinence (weeks 9-12) was associated with multiple nAChR subunit genes (including CHRNB2, CHRNA5, and CHRNA4) (OR=1.76; 95% CI: 1.23-2.52) (p<0.005); for bupropion, abstinence was associated with CYP2B6 (OR=1.78; 95% CI: 1.27-2.50) (p<0.001). Incidence of nausea was associated with several nAChR subunit genes (OR=0.50; 95% CI: 0.36-0.70) (p<0.0001) and time to relapse after quitting was associated with HTR3B (HR=1.97; 95% CI: 1.45-2.68) (p<0.0001). These data provide evidence for multiple genetic loci contributing to smoking cessation and therapeutic response. Different loci are associated with varenicline vs bupropion response, suggesting that additional research may identify clinically useful markers to guide treatment decisions.

Asthma-associated polymorphisms in 17q21 influence cord blood ORMDL3 and GSDMA gene expression and IL-17 secretion.

PubMed

Lluis, Anna; Schedel, Michaela; Liu, Jing; Illi, Sabina; Depner, Martin; von Mutius, Erika; Kabesch, Michael; Schaub, Bianca

2011-06-01

In a genome-wide association study, genetic variants on chromosome 17q21 were strongly associated with childhood asthma and orosomucoid 1-like 3 (ORMDL3) gene expression. Regulation of the 17q21 locus and its immunologic relevance early in life have not been well characterized. We investigated the relation between polymorphisms and mRNA expression of 17q21 locus genes and their influence on T-cell subsets in cord blood. In 200 children of our cord blood study, 17q21 polymorphisms were genotyped by matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Gene expression was assessed for ORMDL3; gasdermin A (GSDMA, alias GSDM1); gasdermin B (GSDMB, alias GSDML); Ikaros family zinc finger 3 (ZNFN1A3), zona pellucida binding protein 2 (ZPBP2); and proteasome (prosome, macropain) 26S subunit, non-ATPase, 3 (PSMD3), in cord blood mononuclear cells (CBMCs) and for ORMDL3 in peripheral blood (real-time RT-PCR). Mononuclear cells were assessed before and after microbial (lipid A/peptidoglycan), phytohemagglutinin, or allergen (Der p 1) stimulation. Regulatory T-associated markers (forkhead box protein 3, glucocorticoid-induced TNF receptor, lymphocyte activation gene 3 mRNA expression) and T(h)2/T(h)1/T(h)17 cytokines were examined. In CBMCs, single genetic risk variants within 17q21 were associated with increased ORMDL3 (Der p 1 stimulation; P ≤ .01) and GSDMA expression (phytohemagglutinin/Der p 1 stimulation; P ≤ .05). Children homozygous for all 4 risk alleles for 17q21 tagging single nucleotide polymorphisms showed increased expression for ORMDL3 (Der p 1; P = .002) and GSDMA (phytohemagglutinin; P = .0009/Der p 1; P = .004). CBMC ORMDL3 expression was lower compared with PBMCs (P ≤ .0003) and increased in both CBMC and PBMC after stimulation (phytohemagglutinin/lipid A/peptidoglycan/Der p 1; P ≤ .006 and phytohemagglutinin/peptidoglycan; P < .05, respectively). No correlation between 17q21 polymorphisms and regulatory T/T(h)2/T(h)1 lineages was detectable. However, 17q21 risk allele carriers showed significantly increased IL-17 secretion (unstimulated, phytohemagglutinin-stimulated). Our results suggest an association of 17q21 polymorphisms with ORMDL3, GSDMA expression, and IL-17 secretion early in life. These observations may imply a functional role of the 17q21 locus affecting T-cell development during immune maturation. Copyright © 2011 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

Prevalence of combinatorial CYP2C9 and VKORC1 genotypes in Puerto Ricans: implications for warfarin management in Hispanics.

PubMed

Duconge, Jorge; Cadilla, Carmen L; Windemuth, Andreas; Kocherla, Mohan; Gorowski, Krystyna; Seip, Richard L; Bogaard, Kali; Renta, Jessica Y; Piovanetti, Paola; D'Agostino, Darrin; Santiago-Borrero, Pedro J; Ruaño, Gualberto

2009-01-01

Polymorphisms in the cytochrome P450 2C9 (CYP2C9) and vitamin K epoxide reductase complex subunit 1 (VKORC1) genes significantly alter the effective warfarin dose. We determined the frequencies of alleles, single carriers, and double carriers of single nucleotide polymorphisms (SNPs) in the CYP2C9 and VKORC1 genes in a Puerto Rican cohort and gauged the impact of these polymorphisms on warfarin dosage using a published algorithm. A total of 92 DNA samples were genotyped using Luminex x-MAP technology. The polymorphism frequencies were 6.52%, 5.43% and 28.8% for CYP2C9 *2, *3 and VKORC1-1639 C>A polymorphisms, respectively. The prevalence of combinatorial genotypes was 16% for carriers of both the CYP2C9 and VKORC1 polymorphisms, 9% for carriers of CYP2C9 polymorphisms, 35% for carriers of the VKORC1 polymorphism, and the remaining 40% were non-carriers for either gene. Based on a published warfarin dosing algorithm, single, double and triple carriers of functionally deficient polymorphisms predict reductions of 1.0-1.6, 2.0-2.9, and 2.9-3.7 mg/day, respectively, in warfarin dose. Overall, 60% of the population carried at least a single polymorphism predicting deficient warfarin metabolism or responsiveness and 13% were double carriers with polymorphisms in both genes studied. Combinatorial genotyping of CYP2C9 and VKORC1 can allow for individualized dosing of warfarin among patients with gene polymorphisms, potentially reducing the risk of stroke or bleeding.

Sequence and functional characterization of hypoxia-inducible factors, HIF1α, HIF2αa, and HIF3α, from the estuarine fish, Fundulus heteroclitus.

PubMed

Townley, Ian K; Karchner, Sibel I; Skripnikova, Elena; Wiese, Thomas E; Hahn, Mark E; Rees, Bernard B

2017-03-01

The hypoxia-inducible factor (HIF) family of transcription factors plays central roles in the development, physiology, pathology, and environmental adaptation of animals. Because many aquatic habitats are characterized by episodes of low dissolved oxygen, fish represent ideal models to study the roles of HIF in the response to aquatic hypoxia. The estuarine fish Fundulus heteroclitus is found in habitats prone to hypoxia. It responds to low oxygen via behavioral, physiological, and molecular changes, and one member of the HIF family, HIF2α, has been previously described. Herein, cDNA sequencing, phylogenetic analyses, and genomic approaches were used to determine other members of the HIFα family from F. heteroclitus and their relationships to HIFα subunits from other vertebrates. In vitro and cellular approaches demonstrated that full-length forms of HIF1α, HIF2α, and HIF3α independently formed complexes with the β-subunit, aryl hydrocarbon receptor nuclear translocator, to bind to hypoxia response elements and activate reporter gene expression. Quantitative PCR showed that HIFα mRNA abundance varied among organs of normoxic fish in an isoform-specific fashion. Analysis of the F. heteroclitus genome revealed a locus encoding a second HIF2α-HIF2αb-a predicted protein lacking oxygen sensing and transactivation domains. Finally, sequence analyses demonstrated polymorphism in the coding sequence of each F. heteroclitus HIFα subunit, suggesting that genetic variation in these transcription factors may play a role in the variation in hypoxia responses among individuals or populations. Copyright © 2017 the American Physiological Society.

Molecular and functional characterization of seven Na+/K+-ATPase β subunit paralogs in Senegalese sole (Solea senegalensis Kaup, 1858).

PubMed

Armesto, Paula; Infante, Carlos; Cousin, Xavier; Ponce, Marian; Manchado, Manuel

2015-04-01

In the present work, seven genes encoding Na(+),K(+)-ATPase (NKA) β-subunits in the teleost Solea senegalensis are described for the first time. Sequence analysis of the predicted polypeptides revealed a high degree of conservation with those of other vertebrate species and maintenance of important motifs involved in structure and function. Phylogenetic analysis clustered the seven genes into four main clades: β1 (atp1b1a and atp1b1b), β2 (atp1b2a and atp1b2b), β3 (atp1b3a and atp1b3b) and β4 (atp1b4). In juveniles, all paralogous transcripts were detected in the nine tissues examined albeit with different expression patterns. The most ubiquitous expressed gene was atp1b1a whereas atp1b1b was mainly detected in osmoregulatory organs (gill, kidney and intestine), and atp1b2a, atp1b2b, atp1b3a, atp1b3b and atp1b4 in brain. An expression analysis in three brain regions and pituitary revealed that β1-type transcripts were more abundant in pituitary than the other β paralogs with slight differences between brain regions. Quantification of mRNA abundance in gills after a salinity challenge showed an activation of atp1b1a and atp1b1b at high salinity water (60 ppt) and atp1b3a and atp1b3b in response to low salinity (5 ppt). Transcriptional analysis during larval development showed specific expression patterns for each paralog. Moreover, no differences in the expression profiles between larvae cultivated at 10 and 35 ppt were observed except for atp1b4 with higher mRNA levels at 10 than 35 ppt at 18 days post hatch. Whole-mount in situ hybridization analysis revealed that atp1b1b was mainly localized in gut, pronephric tubule, gill, otic vesicle, and chordacentrum of newly hatched larvae. All these data suggest distinct roles of NKA β subunits in tissues, during development and osmoregulation with β1 subunits involved in the adaptation to hyperosmotic conditions and β3 subunits to hypoosmotic environments. Copyright © 2014 Elsevier Inc. All rights reserved.

Characterization of a wheat mutant missing low-molecular-weight glutenin subunits encoded by the B-genome

USDA-ARS?s Scientific Manuscript database

DH20, a new wheat mutant missing low-molecular weight glutenin subunits encoded by the Glu-B3 locus, was discovered among double haploid lines obtained from a cross between the Korean wheat cultivars Keumkang and Olgeuru. Absence of the Glu-B3 LMW-GS proteins was determined by one-dimensional gel e...

The CYP3A4 *1B polymorphism and prostate cancer susceptibility in a Portuguese population.

PubMed

Nogal, Ana; Coelho, Ana; Catarino, Raquel; Morais, António; Lobo, Francisco; Medeiros, Rui

2007-09-01

Testosterone exposure has been implicated in prostate carcinogenesis, and genes that alter its metabolism, such as CYP3A4, have been associated with prostate cancer susceptibility. The aim of our study was to assess the relationship between the CYP3A4 *1B polymorphism and its possible role in the development of prostate cancer. DNA samples obtained from the peripheral blood cells of 414 individuals diagnosed with prostate cancer and 337 healthy male donors were used in this case-control study. The CYP3A4*1B polymorphism was analyzed by polymerase chain reaction-restriction fragment length polymorphism methodology. We found no statistically significant differences in the distribution of the CYP3A4*1B genotypes between cases and controls (P = 0.470; odds ratio = 1.191; 95% confidence interval=0.740-1.918), as well as after the stratification of our analysis, according to important clinicopathologic parameters of prostate cancer. Our results suggest that the CYP3A4*1B polymorphism is not associated with prostate cancer risk within the Portuguese population.

Fc gamma receptor IIIb polymorphism and systemic lupus erythematosus: association with disease susceptibility and identification of a novel FCGR3B*01 variant.

PubMed

Santos, V C; Grecco, M; Pereira, K M C; Terzian, C C N; Andrade, L E C; Silva, N P

2016-10-01

The objective of this study was to evaluate the association between Fc gamma receptor IIIb polymorphism and susceptibility to systemic lupus erythematosus and clinical traits of the disease. Genomic DNA was obtained from 303 consecutive systemic lupus erythematosus patients and 300 healthy blood donors from the southeastern region of Brazil. The polymorphic region of the FCGR3B gene was sequenced and the alleles FCGR3B*01, FCGR3B*02 and FCGR3B*03 were analyzed. The FCGR3B*01 allele was more frequent in systemic lupus erythematosus patients (43.1%) while the FCGR3B*02 allele prevailed among controls (63.7%) (P = 0.001). The FCGR3B*03 allele was found equally in both groups. The FCGR3B*01/*01 (20.7%) and FCGR3B*01/*02 (41.1%) genotypes were more frequent among systemic lupus erythematosus patients (P = 0.028 and P = 0.012, respectively) while the FCGR3B*02/*02 genotype was more frequent in controls (45.5%) (P < 0.001). One variant of the FCGR3B*01 allele previously described in Germany was found in only one control. A new variant of the FCGR3B*01 allele with two substitutions (A227G/G277A) was found in one control. Three variants of the FCGR3B*02 allele previously described in African-Americans, Brazilians, Chinese and Japanese were found in ten 10 patients and two controls. In addition, several single nucleotide polymorphisms at non-polymorphic positions were identified in both patients and controls. Susceptibility to systemic lupus erythematosus was associated with the FCGR3B*01 allele, as well as with the FCGR3B*01/*01 and FCGR3B*01/*02 genotypes. No association was found between FCGR3B genotypes and clinical manifestations, disease severity or the presence of autoantibodies. © The Author(s) 2016.

SB-205384 Is a Positive Allosteric Modulator of Recombinant GABAA Receptors Containing Rat α3, α5, or α6 Subunit Subtypes Coexpressed with β3 and γ2 Subunits

PubMed Central

Heidelberg, Laura S.; Warren, James W.

2013-01-01

Many drugs used to treat anxiety are positive modulators of GABAA receptors, which mediate fast inhibitory neurotransmission. The GABAA receptors can be assembled from a combination of at least 16 different subunits. The receptor’s subunit composition determines its pharmacologic and functional properties, and subunit expression varies throughout the brain. A primary goal for new treatments targeting GABAA receptors is the production of subunit-selective modulators acting upon a discrete population of receptors. The anxiolytic 4-amino-7-hydroxy-2-methyl-5,6,7,8,-tetrahydrobenzo[b]thieno[2,3-b]pyridine-3-carboxylic acid, but-2-ynyl ester (SB-205384) is widely considered to be selective for α3-containing GABAA receptors. However, it has been tested only on α1-, α2-, and α3-containing receptors. We examined the activity of SB-205384 at recombinant receptors containing the six different α subunits and found that receptors containing the α3, α5, and α6 subunits were potentiated by SB-205384, with the α6 subunit conferring the greatest responsiveness. Properties associated with chimeric α1/α6 subunits suggested that multiple structural domains influence sensitivity to SB-205384. Point mutations of residues within the extracellular N-terminal domain identified a leucine residue located in loop E of the agonist binding site as an important determinant of high sensitivity to modulation. In the α6 subunit the identity of this residue is species-dependent, with the leucine found in rat subunits but not in human. Our results indicate that SB-205384 is not an α3-selective modulator, and instead acts at several GABAA receptor isoforms. These findings have implications for the side-effect profile of this anxiolytic as well as for its use in neuronal and animal studies as a marker for contribution from α3-containing receptors. PMID:23902941

Polymorphism of the Pv200L Fragment of Merozoite Surface Protein-1 of Plasmodium vivax in Clinical Isolates from the Pacific Coast of Colombia

PubMed Central

Valderrama-Aguirre, Augusto; Zúñiga-Soto, Evelin; Mariño-Ramírez, Leonardo; Moreno, Luz Ángela; Escalante, Ananías A.; Arévalo-Herrera, Myriam; Herrera, Sócrates

2011-01-01

Merozoite surface protein 1 (MSP-1) is a polymorphic malaria protein with functional domains involved in parasite erythrocyte interaction. Plasmodium vivax MSP-1 has a fragment (Pv200L) that has been identified as a potential subunit vaccine because it is highly immunogenic and induces partial protection against infectious parasite challenge in vaccinated monkeys. To determine the extent of genetic polymorphism and its effect on the translated protein, we sequenced the Pv200L coding region from isolates of 26 P. vivax-infected patients in a malaria-endemic area of Colombia. The extent of nucleotide diversity (π) in these isolates (0.061 ± 0.004) was significantly lower (P ≤ 0.001) than that observed in Thai and Brazilian isolates; 0.083 ± 0.006 and 0.090 ± 0.006, respectively. We found two new alleles and several previously unidentified dimorphic substitutions and significant size polymorphism. The presence of highly conserved blocks in this fragment has important implications for the development of Pv200L as a subunit vaccine candidate. PMID:21292880

Association between DNA methyltransferase gene polymorphism and Parkinson's disease.

PubMed

Pezzi, Julio Carlos; de Bem, Cintia Monique Boschmann Ens; da Rocha, Tatiane Jacobsen; Schumacher-Schuh, Artur F; Chaves, Marcia Lorena Fagundes; Rieder, Carlos Roberto; Hutz, Mara H; Fiegenbaum, Marilu; Camozzato, Ana Luiza

2017-02-03

Parkinson's disease (PD) is a common and complex neurodegenerative disorder, the second most prevalent, only behind Alzheimer's disease. Recent studies suggest that environmental factors may contribute for neurodegeneration through induction of epigenetic modifications, such as DNA methylation, that is carried out by enzymes, such as DNMT1 and DNMT3B. This present study targeted to investigate the association among DNMT1 and DNMT3B polymorphisms with PD. Five hundred and twenty-two participants (214 PD patients following UK Brain Bank criteria and 308 healthy individuals) were evaluated. DNA was obtained from whole blood and genotypes were detected by an allelic discrimination assay using TaqMan ® MGB probes on a real-time PCR system. The polymorphisms studied were rs2162560 and rs759920 (DNMT1) and rs2424913, rs998382 and rs2424932 (DNMT3B). Was found association between DNMT3B rs2424913 in T allele carriers with PD. The presence of the T allele was associated with PD (OR=1.80, 95% CI 1.16-2.81, p=0.009). No significant difference was observed for others DNMT3B SNPs. Also, no association between PD and the control group were observed for DNMT1 polymorphisms. This is the first study addressing an association between DNMT3B polymorphism and PD. The polymorphism may play a role in the pathogenesis of PD. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

PREVALENCE OF COMBINATORIAL CYP2C9 AND VKORC1 GENOTYPES IN PUERTO RICANS: IMPLICATIONS FOR WARFARIN MANAGEMENT IN HISPANICS

PubMed Central

Duconge, Jorge; Cadilla, Carmen L.; Windemuth, Andreas; Kocherla, Mohan; Gorowski, Krystyna; Seip, Richard L.; Bogaard, Kali; Renta, Jessica Y.; Piovanetti, Paola; D’Agostino, Darrin; Santiago-Borrero, Pedro J.; Ruaño, Gualberto

2010-01-01

Polymorphisms in the cytochrome P450 2C9 (CYP2C9) and vitamin K epoxide reductase complex subunit 1 (VKORC1) genes significantly alter the effective warfarin dose. We determined the frequencies of alleles, single carriers, and double carriers of single nucleotide polymorphisms (SNPs) in the CYP2C9 and VKORC1 genes in a Puerto Rican cohort and gauged the impact of these polymorphisms on warfarin dosage using a published algorithm. A total of 92 DNA samples were genotyped using Luminex® x-MAP technology. The polymorphism frequencies were 6.52%, 5.43% and 28.8% for CYP2C9 *2, *3 and VKORC1-1639 G>A polymorphisms, respectively. The prevalence of combinatorial genotypes was 16% for carriers of both the CYP2C9 and VKORC1 polymorphisms, 9% for carriers of CYP2C9 polymorphisms, 35% for carriers of the VKORC1 polymorphism, and the remaining 40% were non-carriers for either gene. Based on a published warfarin dosing algorithm, single, double and triple carriers of functionally deficient polymorphisms predict reductions of 1.0–1.6, 2.0–2.9, and 2.9–3.7 mg/day, respectively, in warfarin dose. Overall, 60% of the population carried at least a single polymorphism predicting deficient warfarin metabolism or responsiveness and 13% were double carriers with polymorphisms in both genes studied. Combinatorial genotyping of CYP2C9 and VKORC1 can allow for individualized dosing of warfarin among patients with gene polymorphisms, potentially reducing the risk of stroke or bleeding. PMID:20073138

Quantitative RT-PCR for inhibin/activin subunits: measurements of rat hypothalamic and ovarian inhibin/activin subunit mRNAs during the estrous cycle.

PubMed

Murata, T; Takizawa, T; Funaba, M; Fujimura, H; Murata, E; Takahashi, M; Torii, K

1997-02-01

Inhibins (alpha-beta(A) and alpha-beta(B)) and activins (beta(A)-beta(A), beta(A)-beta(B) and beta(B)-beta(B)) were originally isolated from ovarian follicular fluids as FSH secretion modifiers. Inhibin/activin subunits, alpha, beta(A) and beta(B), are widely distributed in several tissues, including gonads and brain, and inhibins and activins have been reported to be involved in ovarian or hypothalamic functions. In this study, we established and employed a competitive RT-PCR assay system for rat inhibin/activin subunits by capillary electrophoresis to determine rat hypothalamic and ovarian inhibin/activin subunit mRNA levels during the estrous cycle. Linearity of standards for alpha, beta(A), and beta(B) subunit assays were between 0.01-0.3 amol, 0.003-0.09 amol and 0.002-0.02 amol of each fragment DNA as a standard, respectively. Hypothalamic beta(A) subunit mRNA during the estrous morning (1000 h) tended to be increased compared with that of the proestrous evening (1700 h), although they were not significantly different. Ovarian alpha subunit mRNA levels tended to be increased during the proestrous morning (1000 h) and were significantly increased in the proestrous evening (1700 h), compared with diestrus and estrus (P < 0.05). Ovarian beta(A) subunit mRNA was also significantly higher in the proestrous evening, compared with diestrus and estrus (P < 0.05), but in the case of beta(B) subunit mRNA there was no difference among diestrus, proestrus and estrus. We thus established a sensitive competitive RT-PCR system for the measurement of inhibin/activin alpha, beta(A) and beta(B) subunits, and this assay system would be helpful for the study of inhibin/activin action in brain and other tissues where these factors are expressed at low levels.

Genetic expansion of chaperonin-containing TCP-1 (CCT/TRiC) complex subunits yields testis-specific isoforms required for spermatogenesis in planarian flatworms.

PubMed

Counts, Jenna T; Hester, Tasha M; Rouhana, Labib

2017-12-01

Chaperonin-containing Tail-less complex polypeptide 1 (CCT) is a highly conserved, hetero-oligomeric complex that ensures proper folding of actin, tubulin, and regulators of mitosis. Eight subunits (CCT1-8) make up this complex, and every subunit has a homolog expressed in the testes and somatic tissue of the planarian flatworm Schmidtea mediterranea. Gene duplications of four subunits in the genomes of S. mediterranea and other planarian flatworms created paralogs to CCT1, CCT3, CCT4, and CCT8 that are expressed exclusively in the testes. Functional analyses revealed that each CCT subunit expressed in the S. mediterranea soma is essential for homeostatic integrity and survival, whereas sperm elongation defects were observed upon knockdown of each individual testis-specific paralog (Smed-cct1B; Smed-cct3B; Smed-cct4A; and Smed-cct8B), regardless of potential redundancy with paralogs expressed in both testes and soma (Smed-cct1A; Smed-cct3A; Smed-cct4B; and Smed-cct8A). Yet, no detriment was observed in the number of adult somatic stem cells (neoblasts) that maintain differentiated tissue in planarians. Thus, expression of all eight CCT subunits is required to execute the essential functions of the CCT complex. Furthermore, expression of the somatic paralogs in planarian testes is not sufficient to complete spermatogenesis when testis-specific paralogs are knocked down, suggesting that the evolution of chaperonin subunits may drive changes in the development of sperm structure and that correct CCT subunit stoichiometry is crucial for spermiogenesis. © 2017 Wiley Periodicals, Inc.

β Subunits Control the Effects of Human Kv4.3 Potassium Channel Phosphorylation.

PubMed

Abbott, Geoffrey W

2017-01-01

The transient outward K + current, I to , activates early in the cardiac myocyte action potential, to begin repolarization. Human I to is generated primarily by two Kv4.3 potassium channel α subunit splice variants (Kv4.3L and Kv4.3S) that diverge only by a C-terminal, membrane-proximal, 19-residue stretch unique to Kv4.3L. Protein kinase C (PKC) phosphorylation of threonine 504 within the Kv4.3L-specific 19-residues mediates α-adrenergic inhibition of I to in human heart. Kv4.3 is regulated in human heart by various β subunits, including cytosolic KChIP2b and transmembrane KCNEs, yet their impact on the functional effects of human Kv4.3 phosphorylation has not been reported. Here, this gap in knowledge was addressed using human Kv4.3 splice variants, T504 mutants, and human β subunits. Subunits were co-expressed in Xenopus laevis oocytes and analyzed by two-electrode voltage-clamp, using phorbol 12-myristate 13-acetate (PMA) to stimulate PKC. Unexpectedly, KChIP2b removed the inhibitory effect of PKC on Kv4.3L (but not Kv4.3L threonine phosphorylation by PKC per-se ), while co-expression with KCNE2, but not KCNE4, restored PKC-dependent inhibition of Kv4.3L-KChIP2b to quantitatively resemble previously reported effects of α-adrenergic modulation of human ventricular I to . In addition, PKC accelerated recovery from inactivation of Kv4.3L-KChIP2b channels and, interestingly, of both Kv4.3L and Kv4.3S alone. Thus, β subunits regulate the response of human Kv4.3 to PKC phosphorylation and provide a potential mechanism for modifying the response of I to to α-adrenergic regulation in vivo .

β Subunits Control the Effects of Human Kv4.3 Potassium Channel Phosphorylation

PubMed Central

Abbott, Geoffrey W.

2017-01-01

The transient outward K+ current, Ito, activates early in the cardiac myocyte action potential, to begin repolarization. Human Ito is generated primarily by two Kv4.3 potassium channel α subunit splice variants (Kv4.3L and Kv4.3S) that diverge only by a C-terminal, membrane-proximal, 19-residue stretch unique to Kv4.3L. Protein kinase C (PKC) phosphorylation of threonine 504 within the Kv4.3L-specific 19-residues mediates α-adrenergic inhibition of Ito in human heart. Kv4.3 is regulated in human heart by various β subunits, including cytosolic KChIP2b and transmembrane KCNEs, yet their impact on the functional effects of human Kv4.3 phosphorylation has not been reported. Here, this gap in knowledge was addressed using human Kv4.3 splice variants, T504 mutants, and human β subunits. Subunits were co-expressed in Xenopus laevis oocytes and analyzed by two-electrode voltage-clamp, using phorbol 12-myristate 13-acetate (PMA) to stimulate PKC. Unexpectedly, KChIP2b removed the inhibitory effect of PKC on Kv4.3L (but not Kv4.3L threonine phosphorylation by PKC per-se), while co-expression with KCNE2, but not KCNE4, restored PKC-dependent inhibition of Kv4.3L-KChIP2b to quantitatively resemble previously reported effects of α-adrenergic modulation of human ventricular Ito. In addition, PKC accelerated recovery from inactivation of Kv4.3L-KChIP2b channels and, interestingly, of both Kv4.3L and Kv4.3S alone. Thus, β subunits regulate the response of human Kv4.3 to PKC phosphorylation and provide a potential mechanism for modifying the response of Ito to α-adrenergic regulation in vivo. PMID:28919864

Elevated breast cancer risk in irradiated BALB/c mice associates with unique functional polymorphism of the Prkdc (DNA-dependent protein kinase catalytic subunit) gene

NASA Technical Reports Server (NTRS)

Yu, Y.; Okayasu, R.; Weil, M. M.; Silver, A.; McCarthy, M.; Zabriskie, R.; Long, S.; Cox, R.; Ullrich, R. L.

2001-01-01

Female BALB/c mice are unusually radiosensitive and more susceptible than C57BL/6 and other tested inbred mice to ionizing radiation (IR)-induced mammary tumors. This breast cancer susceptibility is correlated with elevated susceptibility for mammary cell transformation and genomic instability following irradiation. In this study, we report the identification of two BALB/c strain-specific polymorphisms in the coding region of Prkdc, the gene encoding the DNA-dependent protein kinase catalytic subunit, which is known to be involved in DNA double-stranded break repair and post-IR signal transduction. First, we identified an A --> G transition at base 11530 resulting in a Met --> Val conversion at codon 3844 (M3844V) in the phosphatidylinositol 3-kinase domain upstream of the scid mutation (Y4046X). Second, we identified a C --> T transition at base 6418 resulting in an Arg --> Cys conversion at codon 2140 (R2140C) downstream of the putative leucine zipper domain. This unique PrkdcBALB variant gene is shown to be associated with decreased DNA-dependent protein kinase catalytic subunit activity and with increased susceptibility to IR-induced genomic instability in primary mammary epithelial cells. The data provide the first evidence that naturally arising allelic variation in a mouse DNA damage response gene may associate with IR response and breast cancer risk.

Genetic diversity of Taenia asiatica from Thailand and other geographical locations as revealed by cytochrome c oxidase subunit 1 sequences.

PubMed

Anantaphruti, Malinee Thairungroj; Thaenkham, Urusa; Watthanakulpanich, Dorn; Phuphisut, Orawan; Maipanich, Wanna; Yoonuan, Tippayarat; Nuamtanong, Supaporn; Pubampen, Somjit; Sanguankiat, Surapol

2013-02-01

Twelve 924 bp cytochrome c oxidase subunit 1 (cox1) mitochondrial DNA sequences from Taenia asiatica isolates from Thailand were aligned and compared with multiple sequence isolates from Thailand and 6 other countries from the GenBank database. The genetic divergence of T. asiatica was also compared with Taenia saginata database sequences from 6 different countries in Asia, including Thailand, and 3 countries from other continents. The results showed that there were minor genetic variations within T. asiatica species, while high intraspecies variation was found in T. saginata. There were only 2 haplotypes and 1 polymorphic site found in T. asiatica, but 8 haplotypes and 9 polymorphic sites in T. saginata. Haplotype diversity was very low, 0.067, in T. asiatica and high, 0.700, in T. saginata. The very low genetic diversity suggested that T. asiatica may be at a risk due to the loss of potential adaptive alleles, resulting in reduced viability and decreased responses to environmental changes, which may endanger the species.

Genetic Diversity of Taenia asiatica from Thailand and Other Geographical Locations as Revealed by Cytochrome c Oxidase Subunit 1 Sequences

PubMed Central

Thaenkham, Urusa; Watthanakulpanich, Dorn; Phuphisut, Orawan; Maipanich, Wanna; Yoonuan, Tippayarat; Nuamtanong, Supaporn; Pubampen, Somjit; Sanguankiat, Surapol

2013-01-01

Twelve 924 bp cytochrome c oxidase subunit 1 (cox1) mitochondrial DNA sequences from Taenia asiatica isolates from Thailand were aligned and compared with multiple sequence isolates from Thailand and 6 other countries from the GenBank database. The genetic divergence of T. asiatica was also compared with Taenia saginata database sequences from 6 different countries in Asia, including Thailand, and 3 countries from other continents. The results showed that there were minor genetic variations within T. asiatica species, while high intraspecies variation was found in T. saginata. There were only 2 haplotypes and 1 polymorphic site found in T. asiatica, but 8 haplotypes and 9 polymorphic sites in T. saginata. Haplotype diversity was very low, 0.067, in T. asiatica and high, 0.700, in T. saginata. The very low genetic diversity suggested that T. asiatica may be at a risk due to the loss of potential adaptive alleles, resulting in reduced viability and decreased responses to environmental changes, which may endanger the species. PMID:23467439

Ephrin-B3 regulates glutamate receptor signaling at hippocampal synapses

PubMed Central

Antion, Marcia D.; Christie, Louisa A.; Bond, Allison M.; Dalva, Matthew B.; Contractor, Anis

2010-01-01

B-ephrin - EphB receptor signaling modulates NMDA receptors by inducing tyrosine phosphorylation of NR2 subunits. Ephrins and EphB RTKs are localized to postsynaptic compartments in the CA1, and therefore potentially interact in a non-canonical cis-configuration. However, it is not known whether cis- configured receptor-ligand signaling is utilized by this class of RTKs, and whether this might influence excitatory synapses. We found that ablation of ephrin-B3 results in an enhancement of the NMDA receptor component of synaptic transmission relative to the AMPA receptor component in CA1 synapses. Synaptic AMPA receptor expression is reduced in ephrin-B3 knockout mice, and there is a marked enhancement of tyrosine phosphorylation of the NR2B receptor subunit. In a reduced system co-expression of ephrin-B3 attenuated EphB2-mediated NR2B tyrosine phosphorylation. Moreover, phosphorylation of EphB2 was elevated in the hippocampus of ephrin-B3 knockout mice, suggesting that regulation of EphB2 activity is lost in these mice. Direct activation of EphB RTKs resulted in phosphorylation of NR2B and a potential signaling partner, the non-receptor tyrosine kinase Pyk2. Our data suggests that ephrin-B3 limits EphB RTK-mediated phosphorylation of the NR2B subunit through an inhibitory cis- interaction which is required for the correct function of glutamatergic CA1 synapses. PMID:20678574

The relationship of polymorphisms in ABCC2 and SLCO1B3 with docetaxel pharmacokinetics and neutropenia: CALGB 60805 (Alliance).

PubMed

Lewis, Lionel D; Miller, Antonius A; Owzar, Kouros; Bies, Robert R; Markova, Svetlana; Jiang, Chen; Kroetz, Deanna L; Egorin, Merrill J; McLeod, Howard L; Ratain, Mark J

2013-01-01

Docetaxel-related neutropenia was associated with polymorphisms in the drug transporters ABCC2 and SLCO1B3 in Japanese cancer patients. We hypothesized that this association is because of reduced docetaxel clearance, associated with polymorphisms in those genes. We studied 64 US cancer patients who received a single cycle of 75 mg/m of docetaxel monotherapy. We found that the ABCC2 polymorphism at rs-12762549 trended to show a relationship with reduced docetaxel clearance (P=0.048), but not with neutropenia. There was no significant association of the SLCO1B3 polymorphisms with docetaxel clearance or neutropenia. We conclude that the relationship between docetaxel-associated neutropenia and polymorphisms in drug transporters identified in Japanese patients was not confirmed in this cohort of US cancer patients. © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins.

Expression of NMDA receptor subunits in human blood lymphocytes: A peripheral biomarker in online computer game addiction.

PubMed

Sadat-Shirazi, Mitra-Sadat; Vousooghi, Nasim; Alizadeh, Bentolhoda; Makki, Seyed Mohammad; Zarei, Seyed Zeinolabedin; Nazari, Shahrzad; Zarrindast, Mohammad Reza

2018-05-23

Background and aims Repeated performance of some behaviors such as playing computer games could result in addiction. The NMDA receptor is critically involved in the development of behavioral and drug addictions. It has been claimed that the expression level of neurotransmitter receptors in the brain may be reflected in peripheral blood lymphocytes (PBLs). Methods Here, using a real-time PCR method, we have investigated the mRNA expression of GluN2A, GluN2D, GluN3A, and GluN3B subunits of the NMDA receptor in PBLs of male online computer game addicts (n = 25) in comparison with normal subjects (n = 26). Results Expression levels of GluN2A, GluN2D, and GluN3B subunits were not statistically different between game addicts and the control group. However, the mRNA expression of the GluN3A subunit was downregulated in PBLs of game addicts. Discussion and conclusions Transcriptional levels of GluN2A and GluN2D subunits in online computer game addicts are similar to our previously reported data of opioid addiction and are not different from the control group. However, unlike our earlier finding of drug addiction, the mRNA expression levels of GluN3A and GluN3B subunits in PBLs of game addicts are reduced and unchanged, respectively, compared with control subjects. It seems that the downregulated state of the GluN3A subunit of NMDA receptor in online computer game addicts is a finding that deserves more studies in the future to see whether it can serve as a peripheral biomarker in addiction studies, where the researcher wants to rule out the confusing effects of abused drugs.

Structural basis of subunit selectivity for competitive NMDA receptor antagonists with preference for GluN2A over GluN2B subunits

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lind, Genevieve E.; Mou, Tung-Chung; Tamborini, Lucia

NMDA-type glutamate receptors are ligand-gated ion channels that contribute to excitatory neurotransmission in the central nervous system (CNS). Most NMDA receptors comprise two glycine-binding GluN1 and two glutamate-binding GluN2 subunits (GluN2A–D). We describe highly potent (S)-5-[(R)-2-amino-2-carboxyethyl]-4,5-dihydro-1H-pyrazole-3-carboxylic acid (ACEPC) competitive GluN2 antagonists, of which ST3 has a binding affinity of 52 nM at GluN1/2A and 782 nM at GluN1/2B receptors. This 15-fold preference of ST3 for GluN1/2A over GluN1/2B is improved compared with NVP-AAM077, a widely used GluN2A-selective antagonist, which we show has 11-fold preference for GluN1/2A over GluN1/2B. Crystal structures of the GluN1/2A agonist binding domain (ABD) heterodimer with boundmore » ACEPC antagonists reveal a binding mode in which the ligands occupy a cavity that extends toward the subunit interface between GluN1 and GluN2A ABDs. Mutational analyses show that the GluN2A preference of ST3 is primarily mediated by four nonconserved residues that are not directly contacting the ligand, but positioned within 12 Å of the glutamate binding site. Two of these residues influence the cavity occupied by ST3 in a manner that results in favorable binding to GluN2A, but occludes binding to GluN2B. Thus, we reveal opportunities for the design of subunit-selective competitive NMDA receptor antagonists by identifying a cavity for ligand binding in which variations exist between GluN2A and GluN2B subunits. This structural insight suggests that subunit selectivity of glutamate-site antagonists can be mediated by mechanisms in addition to direct contributions of contact residues to binding affinity.« less

Structural basis of subunit selectivity for competitive NMDA receptor antagonists with preference for GluN2A over GluN2B subunits

PubMed Central

Lind, Genevieve E.; Mou, Tung-Chung; Tamborini, Lucia; Pomper, Martin G.; De Micheli, Carlo; Conti, Paola; Pinto, Andrea

2017-01-01

NMDA-type glutamate receptors are ligand-gated ion channels that contribute to excitatory neurotransmission in the central nervous system (CNS). Most NMDA receptors comprise two glycine-binding GluN1 and two glutamate-binding GluN2 subunits (GluN2A–D). We describe highly potent (S)-5-[(R)-2-amino-2-carboxyethyl]-4,5-dihydro-1H-pyrazole-3-carboxylic acid (ACEPC) competitive GluN2 antagonists, of which ST3 has a binding affinity of 52 nM at GluN1/2A and 782 nM at GluN1/2B receptors. This 15-fold preference of ST3 for GluN1/2A over GluN1/2B is improved compared with NVP-AAM077, a widely used GluN2A-selective antagonist, which we show has 11-fold preference for GluN1/2A over GluN1/2B. Crystal structures of the GluN1/2A agonist binding domain (ABD) heterodimer with bound ACEPC antagonists reveal a binding mode in which the ligands occupy a cavity that extends toward the subunit interface between GluN1 and GluN2A ABDs. Mutational analyses show that the GluN2A preference of ST3 is primarily mediated by four nonconserved residues that are not directly contacting the ligand, but positioned within 12 Å of the glutamate binding site. Two of these residues influence the cavity occupied by ST3 in a manner that results in favorable binding to GluN2A, but occludes binding to GluN2B. Thus, we reveal opportunities for the design of subunit-selective competitive NMDA receptor antagonists by identifying a cavity for ligand binding in which variations exist between GluN2A and GluN2B subunits. This structural insight suggests that subunit selectivity of glutamate-site antagonists can be mediated by mechanisms in addition to direct contributions of contact residues to binding affinity. PMID:28760974

CRISPR/Cas9-mediated knockout of PiSSK1 reveals essential role of S-locus F-box protein-containing SCF complexes in recognition of non-self S-RNases during cross-compatible pollination in self-incompatible Petunia inflata.

PubMed

Sun, Linhan; Kao, Teh-Hui

2018-06-01

Function of Petunia PiSSK1. Self-incompatibility (SI), an inbreeding-preventing mechanism, is regulated in Petunia inflata by the polymorphic S-locus, which houses multiple pollen-specific S-locus F-box (SLF) genes and a single pistil-specific S-RNase gene. S 2 -haplotype and S 3 -haplotype possess the same 17 polymorphic SLF genes (named SLF1 to SLF17), and each SLF protein produced in pollen is assembled into an SCF (Skp1-Cullin1-F-box) E3 ubiquitin ligase complex. A complete suite of SLF proteins is thought to collectively interact with all non-self S-RNases to mediate their ubiquitination and degradation by the 26S proteasome, allowing cross-compatible pollination. For each SCF SLF complex, the Cullin1 subunit (named PiCUL1-P) and Skp1 subunit (named PiSSK1), like the F-box protein subunits (SLFs), are pollen-specific, raising the possibility that they also evolved specifically to function in SI. Here we used CRISPR/Cas9-meditated genome editing to generate frame-shift indel mutations in PiSSK1 and examined the SI behavior of a T 0 plant (S 2 S 3 ) with biallelic mutations in the pollen genome and two progeny plants (S 2 S 2 ) each homozygous for one of the indel alleles and not carrying the Cas9-containing T-DNA. Their pollen was completely incompatible with pistils of seven otherwise-compatible S-genotypes, but fully compatible with pistils of an S 3 S 3 transgenic plant in which production of S 3 -RNase was completely suppressed by an antisense S 3 -RNase gene, and with pistils of immature flower buds, which produce little S-RNase. These results suggest that PiSSK1 specifically functions in SI and support the hypothesis that SLF-containing SCF complexes are essential for compatible pollination.

Two hydrophobic subunits are essential for the heme b ligation and functional assembly of complex II (succinate-ubiquinone oxidoreductase) from Escherichia coli.

PubMed

Nakamura, K; Yamaki, M; Sarada, M; Nakayama, S; Vibat, C R; Gennis, R B; Nakayashiki, T; Inokuchi, H; Kojima, S; Kita, K

1996-01-05

Complex II (succinate-ubiquinone oxidoreductase) from Escherichia coli is composed of four nonidentical subunits encoded by the sdhCDAB operon. Gene products of sdhC and sdhD are small hydrophobic subunits that anchor the hydrophilic catalytic subunits (flavoprotein and iron-sulfur protein) to the cytoplasmic membrane and are believed to be the components of cytochrome b556 in E. coli complex II. In the present study, to elucidate the role of two hydrophobic subunits in the heme b ligation and functional assembly of complex II, plasmids carrying portions of the sdh gene were constructed and introduced into E. coli MK3, which lacks succinate dehydrogenase and fumarate reductase activities. The expression of polypeptides with molecular masses of about 19 and 17 kDa was observed when sdhC and sdhD were introduced into MK3, respectively, indicating that sdhC encodes the large subunit (cybL) and sdhD the small subunit (cybS) of cytochrome b556. An increase in cytochrome b content was found in the membrane when sdhD was introduced, while the cytochrome b content did not change when sdhC was introduced. However, the cytochrome b expressed by the plasmid carrying sdhD differed from cytochrome b556 in its CO reactivity and red shift of the alpha absorption peak to 557.5 nm at 77 K. Neither hydrophobic subunit was able to bind the catalytic portion to the membrane, and only succinate dehydrogenase activity, not succinate-ubiquinone oxidoreductase activity, was found in the cytoplasmic fractions of the cells. In contrast, significantly higher amounts of cytochrome b556 were expressed in the membrane when sdhC and sdhD genes were both present, and the catalytic portion was found to be localized in the membrane with succinate-ubiquitnone oxidoreductase and succinate oxidase activities. These results strongly suggest that both hydrophobic subunits are required for heme insertion into cytochrome b556 and are essential for the functional assembly of E. coli complex II in the membrane. Accumulation of the catalytic portion in the cytoplasm was found when sdhCDAB was introduced into a heme synthesis mutant, suggesting the importance of heme in the assembly of E. coli complex II.

DNMT3B -579 G>T Promoter Polymorphism and the Risk of Gastric Cancer in the West of Iran.

PubMed

Ahmadi, Kulsom; Soleimani, Azam; Irani, Shiva; Kiani, Aliasghar; Ghanadi, Kourosh; Noormohamadi, Zahra; Sakinejad, Foroozan

2018-06-01

Many studies have suggested that modulation of DNMT3B function caused by single nucleotide polymorphisms of the DNMT3B promoter region may underlie the susceptibility to various cancers such as tumors of the digestive system. The aim of this study was to investigate the effect of -579 G>T polymorphism in the promoter of the DNMT3B gene on risk of gastric cancer in a population from West Iran. We conducted a case-control study in 100 gastric cancer patients and 112 cancer-free controls to assess the correlation between DNMT3B -579 G>T (rs1569686) polymorphism and the risk of gastric cancer. Detection of genotypes of DNMT3B G39179T polymorphism was analyzed by PCR-RFLP. There was no significant difference in the distribution of DNMT3B -579 G>T genotypes between the cases and controls. However, in the stratified analysis by clinicopathological characteristic types, we found that statistically, the risk susceptibility to gastric cancer was significantly associated with tumor grade II and GT/TT genotype of patients, compared to patients having GG genotype, (OR = 5.4737, 95% CI = 1.4746. 20.3184, P = 0.01). Our study suggested that the -579 T allele may increase the relative risk for the progression of clinicopathological characteristic of tumor grade of gastric cancer patients.

A region rich in aspartic acid, arginine, tyrosine, and glycine (DRYG) mediates eukaryotic initiation factor 4B (eIF4B) self-association and interaction with eIF3.

PubMed Central

Méthot, N; Song, M S; Sonenberg, N

1996-01-01

The binding of mRNA to the ribosome is mediated by eukaryotic initiation factors eukaryotic initiation factor 4F (eIF4F), eIF4B, eIF4A, and eIF3, eIF4F binds to the mRNA cap structure and, in combination with eIF4B, is believed to unwind the secondary structure in the 5' untranslated region to facilitate ribosome binding. eIF3 associates with the 40S ribosomal subunit prior to mRNA binding. eIF4B copurifies with eIF3 and eIF4F through several purification steps, suggesting the involvement of a multisubunit complex during translation initiation. To understand the mechanism by which eIF4B promotes 40S ribosome binding to the mRNA, we studied its interactions with partner proteins by using a filter overlay (protein-protein [far Western]) assay and the two-hybrid system. In this report, we show that eIF4B self-associates and also interacts directly with the p170 subunit of eIF3. A region rich in aspartic acid, arginine, tyrosine, and glycine, termed the DRYG domain, is sufficient for self-association of eIF4B, both in vitro and in vivo, and for interaction with the p170 subunit of eIF3. These experiments suggest that eIF4B participates in mRNA-ribosome binding by acting as an intermediary between the mRNA and eIF3, via a direct interaction with the p170 subunit of eIF3. PMID:8816444

Identification of a Kinase in Wheat Germ that Phosphorylates the Large Subunit of Initiation Factor 4F 1

PubMed Central

Humphreys, Jean; Browning, Karen S.; Ravel, Joanne M.

1988-01-01

A kinase has been isolated from wheat (Triticum aestivum) germ that phosphorylates the 220 kilodaltons (kD) subunit of wheat germ initiation factor (eIF) 4F, the 80 kD subunit of eIF-4B (an isozyme form of eIF-4F) and eIF-4G (the functional equivalent to mammalian eIF-4B). The kinase elutes from Sephacryl S-200 slightly in front of ovalbumin. The kinase phosphorylates casein and histone IIA to a small extent, but does not phosphorylate phosvitin. Of the wheat germ initiation factors, elongation factors, and small and large ribosomal subunits, only eIF-4F, eIF-4B, and eIF-4G are phosphorylated to a significant extent. The kinase phosphorylates eIF-4F to the extent of two phosphates per mole of the 220 kD subunit and phosphorylates eIF-4B to the extent of one phosphate per mole of the 80 kD subunit. The 26 kD subunit of eIF-4F and the 28 kD subunit of eIF-4B are not phosphorylated by the kinase. The kinase phosphorylates the 59 kD component of eIF-4G to the extent of 0.25 phosphate per mole of eIF-4G. Phosphorylation of eIF-4F and eIF-4B does not affect their ability to support the binding of mRNA to small ribosomal subunits in vitro. Images Fig. 2 Fig. 3 PMID:16666331

Regulation of protein phosphatase 2A during embryonic diapause process in the silkworm, Bombyx mori.

PubMed

Gu, Shi-Hong; Hsieh, Hsiao-Yen; Lin, Pei-Ling

2017-11-01

Regulation of protein phosphorylation requires coordinated interactions between protein kinases and protein phosphatases. In the present study, we investigated regulation of protein phosphatase 2A (PP2A) during the embryonic diapause process of B. mori. An immunoblotting analysis showed that Bombyx eggs contained a catalytic C subunit, a major regulatory B subunit (B55/PR55 subunit), and a structural A subunit, with the A and B subunits undergoing differential changes between diapause and non-diapause eggs during embryonic process. In non-diapause eggs, eggs whose diapause initiation was prevented by HCl, and eggs in which diapause had been terminated by chilling of diapausing eggs at 5°C for 70days and then were transferred to 25°C, protein levels of the A and B subunits of PP2A gradually increased toward embryonic development. However, protein levels of the A and B subunits in diapause eggs remained at low levels during the first 8days after oviposition. The direct determination of PP2A enzymatic activity showed that the activity remained at low levels in diapause eggs during the first 8days after oviposition. However, in non-diapause eggs, eggs whose diapause initiation was prevented by HCl, and eggs in which diapause had been terminated by chilling, PP2A enzymatic activity sharply increased during the first several days, reached a peak during the middle embryonic development, and then greatly decreased 3 or 4days before hatching. Examination of temporal changes in mRNA expression levels of the catalytic β subunit and regulatory subunit of PP2A showed high levels in eggs whose diapause initiation was prevented by HCl compared to those in diapause eggs. These results demonstrate that the higher PP2A gene expression and PP2A A and B subunit protein levels and increased enzymatic activity are related to embryonic development of B. mori. Copyright © 2017 Elsevier Ltd. All rights reserved.

Two polymorphs of safinamide, a selective and reversible inhibitor of monoamine oxidase B.

PubMed

Ravikumar, Krishnan; Sridhar, Balasubramanian

2010-06-01

Two polymorphs of safinamide {systematic name: (2S)-2-[4-(3-fluorobenzyloxy)benzylamino]propionamide}, C(17)H(19)FN(2)O(2), a potent selective and reversible monoamine oxidase B (MAO-B) inhibitor, are described. Both forms are orthorhombic and regarded as conformational polymorphs due to the differences in the orientation of the 3-fluorobenzyloxy and propanamide groups. Both structures pack with layers in the ac plane. In polymorph (I), the layers have discrete wide and narrow regions which are complementary when located next to adjacent layers. In polymorph (II), the layer has long flanges protruding from each side, which interdigitate when packed with the adjacent layers. N-H...O hydrogen bonds are present in both structures, whereas N-H...F hydrogen bonding is seen in polymorph (I), while N-H...N hydrogen bonding is seen in polymorph (II).

Analysis of APOBEC3A/3B germline deletion polymorphism in breast, cervical and oral cancers from South India and its impact on miRNA regulation.

PubMed

Revathidevi, Sundaramoorthy; Manikandan, Mayakannan; Rao, Arunagiri Kuha Deva Magendhra; Vinothkumar, Vilvanathan; Arunkumar, Ganesan; Rajkumar, Kottayasamy Seenivasagam; Ramani, Rajendran; Rajaraman, Ramamurthy; Ajay, Chandrasekar; Munirajan, Arasambattu Kannan

2016-09-01

Breast cancer and cervical cancer are the leading causes of death in women worldwide as well as in India, whilst oral cancer is the top most common cancer among Asian especially in Indian men in terms of both incidence and mortality rate. Genetic factors determining the predisposition to cancer are being explored to identify the signature genetic variations associated with these cancers. Recently, a germline deletion polymorphism in APOBEC3 gene cluster which completely deletes APOBEC3B coding region has been studied for its association with cancer risk. We screened the germline deletion polymorphism in 409 cancer patients (224 breast cancer, 88 cervical cancer and 97 oral cancer samples), 478 controls and 239 cervical cancer tissue DNAs of South Indian origin. The results suggest that the APOBEC3A/3B deletion polymorphism is not significantly associated with cancer risk in our study population (OR 0.739, 95 % CI, p value 0.91457). Considering the viral restriction property of APOBEC3s, we also screened cervical cancer tissue DNAs for the human papilloma virus infection. We observed a gradual increase in the frequency of HPV16 infection from AA/BB cases (66.86 %) to AA/-- cases (71.43) which signifies the impact of this deletion polymorphism in HPV infection. In addition, we performed in silico analysis to understand the effect of this polymorphism on miRNA regulation of the APOBEC3A/3B fusion transcript. Only 8 APOBEC3B targeting miRNAs were observed to regulate the fusion transcript of which miR-34b-3p and miR-138-5p were found to be frequently downregulated in cancers suggesting miRNA-mediated deregulation of APOBEC3A expression in cancer patients harbouring this particular deletion polymorphism.

The vacuolar ATPase from Entamoeba histolytica: molecular cloning of the gene encoding for the B subunit and subcellular localization of the protein.

PubMed

Meléndez-Hernández, Mayra Gisela; Barrios, María Luisa Labra; Orozco, Esther; Luna-Arias, Juan Pedro

2008-12-23

Entamoeba histolytica is a professional phagocytic cell where the vacuolar ATPase plays a key role. This enzyme is a multisubunit complex that regulates pH in many subcellular compartments, even in those that are not measurably acidic. It participates in a wide variety of cellular processes such as endocytosis, intracellular transport and membrane fusion. The presence of a vacuolar type H+-ATPase in E. histolytica trophozoites has been inferred previously from inhibition assays of its activity, the isolation of the Ehvma1 and Ehvma3 genes, and by proteomic analysis of purified phagosomes. We report the isolation and characterization of the Ehvma2 gene, which encodes for the subunit B of the vacuolar ATPase. This polypeptide is a 55.3 kDa highly conserved protein with 34 to 80% identity to orthologous proteins from other species. Particularly, in silico studies showed that EhV-ATPase subunit B displays 78% identity and 90% similarity to its Dictyostelium ortholog. A 462 bp DNA fragment of the Ehvma2 gene was expressed in bacteria and recombinant polypeptide was used to raise mouse polyclonal antibodies. EhV-ATPase subunit B antibodies detected a 55 kDa band in whole cell extracts and in an enriched fraction of DNA-containing organelles named EhkOs. The V-ATPase subunit B was located by immunofluorescence and confocal microscopy in many vesicles, in phagosomes, plasma membrane and in EhkOs. We also identified the genes encoding for the majority of the V-ATPase subunits in the E. histolytica genome, and proposed a putative model for this proton pump. We have isolated the Ehvma2 gene which encodes for the V-ATPase subunit B from the E. histolytica clone A. This gene has a 154 bp intron and encodes for a highly conserved polypeptide. Specific antibodies localized EhV-ATPase subunit B in many vesicles, phagosomes, plasma membrane and in EhkOs. Most of the orthologous genes encoding for the EhV-ATPase subunits were found in the E. histolytica genome, indicating the conserved nature of V-ATPase in this parasite.

Structure of the protein phosphatase 2A holoenzyme.

PubMed

Xu, Yanhui; Xing, Yongna; Chen, Yu; Chao, Yang; Lin, Zheng; Fan, Eugene; Yu, Jong W; Strack, Stefan; Jeffrey, Philip D; Shi, Yigong

2006-12-15

Protein Phosphatase 2A (PP2A) plays an essential role in many aspects of cellular physiology. The PP2A holoenzyme consists of a heterodimeric core enzyme, which comprises a scaffolding subunit and a catalytic subunit, and a variable regulatory subunit. Here we report the crystal structure of the heterotrimeric PP2A holoenzyme involving the regulatory subunit B'/B56/PR61. Surprisingly, the B'/PR61 subunit has a HEAT-like (huntingtin-elongation-A subunit-TOR-like) repeat structure, similar to that of the scaffolding subunit. The regulatory B'/B56/PR61 subunit simultaneously interacts with the catalytic subunit as well as the conserved ridge of the scaffolding subunit. The carboxyterminus of the catalytic subunit recognizes a surface groove at the interface between the B'/B56/PR61 subunit and the scaffolding subunit. Compared to the scaffolding subunit in the PP2A core enzyme, formation of the holoenzyme forces the scaffolding subunit to undergo pronounced conformational rearrangements. This structure reveals significant ramifications for understanding the function and regulation of PP2A.

AMPA, NMDA and kainate glutamate receptor subunits are expressed in human peripheral blood mononuclear cells (PBMCs) where the expression of GluK4 is altered by pregnancy and GluN2D by depression in pregnant women.

PubMed

Bhandage, Amol K; Jin, Zhe; Hellgren, Charlotte; Korol, Sergiy V; Nowak, Krzysztof; Williamsson, Louise; Sundström-Poromaa, Inger; Birnir, Bryndis

2017-04-15

The amino acid glutamate opens cation permeable ion channels, the iGlu receptors. These ion channels are abundantly expressed in the mammalian brain where glutamate is the main excitatory neurotransmitter. The neurotransmitters and their receptors are being increasingly detected in the cells of immune system. Here we examined the expression of the 18 known subunits of the iGlu receptors families; α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), kainate, N-methyl-d-aspartate (NMDA) and delta in human peripheral blood mononuclear cells (PBMCs). We compared the expression of the subunits between four groups: men, non-pregnant women, healthy pregnant women and depressed pregnant women. Out of 18 subunits of the iGlu receptors, mRNAs for 11 subunits were detected in PBMCs from men and non-pregnant women; AMPA: GluA3, GluA4, kainate: GluK2, GluK4, GluK5, NMDA: GluN1, GluN2C, GluN2D, GluN3A, GluN3B, and delta: GluD1. In the healthy and the depressed pregnant women, in addition, the delta GluD2 subunit was identified. The mRNAs for GluK4, GluK5, GluN2C and GluN2D were expressed at a higher level than other subunits. Gender, pregnancy or depression during pregnancy altered the expression of GluA3, GluK4, GluN2D, GluN3B and GluD1 iGlu subunit mRNAs. The greatest changes recorded were the lower GluA3 and GluK4 mRNA levels in pregnant women and the higher GluN2D mRNA level in healthy but not in depressed pregnant women as compared to non-pregnant individuals. Using subunit specific antibodies, the GluK4, GluK5, GluN1, GluN2C and GluN2D subunit proteins were identified in the PBMCs. The results show expression of specific iGlu receptor subunit in the PBMCs and support the idea of physiology-driven changes of iGlu receptors subtypes in the immune cells. Copyright © 2017 Elsevier B.V. All rights reserved.

Proteomic and Biochemical Comparison of the Cellular Interaction Partners of Human VPS33A and VPS33B.

PubMed

Hunter, Morag R; Hesketh, Geoffrey G; Benedyk, Tomasz H; Gingras, Anne-Claude; Graham, Stephen C

2018-05-17

Multi-subunit tethering complexes control membrane fusion events in eukaryotic cells. Class C core vacuole/endosome tethering (CORVET) and homotypic fusion and vacuole protein sorting (HOPS) are two such complexes, both containing the Sec1/Munc18 protein subunit VPS33A. Metazoans additionally possess VPS33B, which has considerable sequence similarity to VPS33A but does not integrate into CORVET or HOPS complexes and instead stably interacts with VIPAR. It has been recently suggested that VPS33B and VIPAR comprise two subunits of a novel multi-subunit tethering complex (named "CHEVI"), perhaps analogous in configuration to CORVET and HOPS. We utilized the BioID proximity biotinylation assay to compare and contrast the interactomes of VPS33A and VPS33B. Overall, few proteins were identified as associating with both VPS33A and VPS33B, suggesting that these proteins have distinct sub-cellular localizations. Consistent with previous reports, we observed that VPS33A was co-localized with many components of class III phosphatidylinositol 3-kinase (PI3KC3) complexes: PIK3C3, PIK3R4, NRBF2, UVRAG and RUBICON. Although VPS33A clearly co-localized with several subunits of CORVET and HOPS in this assay, no proteins with the canonical CORVET/HOPS domain architecture were found to co-localize with VPS33B. Instead, we identified that VPS33B interacts directly with CCDC22, a member of the CCC complex. CCDC22 does not co-fractionate with VPS33B and VIPAR in gel filtration of human cell lysates, suggesting that CCDC22 interacts transiently with VPS33B/VIPAR rather than forming a stable complex with these proteins in cells. We also observed that the protein complex containing VPS33B and VIPAR is considerably smaller than CORVET/HOPS, suggesting that the CHEVI complex comprises just VPS33B and VIPAR. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Structural Basis of PP2A Inhibition by Small t Antigen

PubMed Central

Cho, Uhn Soo; Morrone, Seamus; Sablina, Anna A; Arroyo, Jason D; Hahn, William C; Xu, Wenqing

2007-01-01

The SV40 small t antigen (ST) is a potent oncoprotein that perturbs the function of protein phosphatase 2A (PP2A). ST directly interacts with the PP2A scaffolding A subunit and alters PP2A activity by displacing regulatory B subunits from the A subunit. We have determined the crystal structure of full-length ST in complex with PP2A A subunit at 3.1 Å resolution. ST consists of an N-terminal J domain and a C-terminal unique domain that contains two zinc-binding motifs. Both the J domain and second zinc-binding motif interact with the intra-HEAT-repeat loops of HEAT repeats 3–7 of the A subunit, which overlaps with the binding site of the PP2A B56 subunit. Intriguingly, the first zinc-binding motif is in a position that may allow it to directly interact with and inhibit the phosphatase activity of the PP2A catalytic C subunit. These observations provide a structural basis for understanding the oncogenic functions of ST. PMID:17608567

CHRNA7 Polymorphisms and Response to Cholinesterase Inhibitors in Alzheimer's Disease

PubMed Central

Weng, Pei-Hsuan; Chen, Jen-Hau; Chen, Ta-Fu; Sun, Yu; Wen, Li-Li; Yip, Ping-Keung; Chu, Yi-Min; Chen, Yen-Ching

2013-01-01

Background CHRNA7 encodes the α7 nicotinic acetylcholine receptor subunit, which is important to Alzheimer's disease (AD) pathogenesis and cholinergic neurotransmission. Previously, CHRNA7 polymorphisms have not been related to cholinesterase inhibitors (ChEI) response. Methods Mild to moderate AD patients received ChEIs were recruited from the neurology clinics of three teaching hospitals from 2007 to 2010 (n = 204). Nine haplotype-tagging single nucleotide polymorphisms of CHRNA7 were genotyped. Cognitive responders were those showing improvement in the Mini-Mental State Examination score ≧2 between baseline and 6 months after ChEI treatment. Results AD women carrying rs8024987 variants [GG+GC vs. CC: adjusted odds ratio (AOR) = 3.62, 95% confidence interval (CI) = 1.47–8.89] and GG haplotype in block1 (AOR = 3.34, 95% CI = 1.38–8.06) had significantly better response to ChEIs (false discovery rate <0.05). These variant carriers using galantamine were 11 times more likely to be responders than female non-carriers using donepezil or rivastigmine. Conclusion For the first time, this study found a significant association between CHRNA7 polymorphisms and better ChEI response. If confirmed by further studies, CHRNA7 polymorphisms may aid in predicting ChEI response and refining treatment choice. PMID:24391883

Low molecular weight glutenin subunit gene Glu-B3h confers superior dough strength and breadmaking quality in wheat (Triticum aestivum L.)

PubMed Central

Wang, Yaping; Zhen, Shoumin; Luo, Nana; Han, Caixia; Lu, Xiaobing; Li, Xiaohui; Xia, Xianchun; He, Zhonghu; Yan, Yueming

2016-01-01

Low molecular weight glutenin subunit is one of the important quality elements in wheat (Triticum aestivum L.). Although considerable allelic variation has been identified, the functional properties of individual alleles at Glu-3 loci are less studied. In this work, we performed the first comprehensive study on the molecular characteristics and functional properties of the Glu-B3h gene using the wheat cultivar CB037B and its Glu-B3 deletion line CB037C. The results showed that the Glu-B3h deletion had no significant effects on plant morphological or yield traits, but resulted in a clear reduction in protein body number and size and main quality parameters, including inferior mixing property, dough strength, loaf volume, and score. Molecular characterization showed that the Glu-B3h gene consists of 1179 bp, and its encoded B-subunit has a longer repetitive domain and an increased number of α-helices, as well as higher expression, which could contribute to superior flour quality. The SNP-based allele-specific PCR markers designed for the Glu-B3h gene were developed and validated with bread wheat holding various alleles at Glu-B3 locus, which could effectively distinguish the Glu-B3h gene from others at the Glu-B3 locus, and have potential applications for wheat quality improvement through marker-assisted selection. PMID:27273251

X-ray structural studies and physicochemical characterization of (E)-6-(3,4-dimethoxyphenyl)-1-ethyl-4-mesitylimino-3-methyl- 3,4-dihydro-2(1H)-pyrimidinone polymorphs.

PubMed

Miyamae, A; Kitamura, S; Tada, T; Koda, S; Yasuda, T

1991-10-01

The polymorphism of (E)-6-(3,4-dimethoxyphenyl)-1-ethyl-4-mesitylimino-3-methyl-3,4-di hydro- 2(1 H)-pyrimidinone (FK664; 1) was characterized by using X-ray powder diffractometry, differential scanning calorimetry (DSC), and IR spectroscopy. Structures of two polymorphs (Forms A and B) were determined by X-ray crystallographic analysis. Form A crystallized in the monoclinic space group P2(1)/c, with a = 13.504(2), b = 6.733(1), c = 24.910(8) A, beta = 96.55(4) degrees, z = 4, and dcal = 1.203 g/cm3, while Form B crystallized in the same space group, with a = 8.067(2), b = 15.128(4), c = 18.657(4) A, beta = 102.34(3) degrees, z = 4, and dcal = 1.216 g/cm3. The conformational features of 1 were very similar between the two polymorphs. Compound 1, in both crystal forms, took an energetically reasonable conformation in three rigid planes, such as 2-pyrimidone, trimethylphenyl, and dimethoxyphenyl rings, but the molecules were packed in different ways between the two polymorphs. In the Form B crystal, a short contact was possible, to form pi-pi interactions between two dimethoxyphenyl groups related with the inversion center in the crystal lattice; this interaction seems to contribute to stabilizing the crystal structure of Form B. Both Forms A and B showed only one endothermic peak due to fusion at 115 and 140 degrees C, respectively, on the DSC thermograms; therefore, it is suggested that there are no transition points between the two polymorphs. The heats of fusion obtained from the DSC thermograms were 33.2(2) kJ/mol for Form A and 36.8(1) kJ/mol for Form B.(ABSTRACT TRUNCATED AT 250 WORDS)

Alpha B- and βA3-crystallins containing d-aspartic acids exist in a monomeric state.

PubMed

Sakaue, Hiroaki; Takata, Takumi; Fujii, Norihiko; Sasaki, Hiroshi; Fujii, Noriko

2015-01-01

Crystallin stability and subunit-subunit interaction are essential for eye lens transparency. There are three types of crystallins in lens, designated as α-, β-, and γ-crystallins. Alpha-crystallin is a hetero-polymer of about 800kDa, consisting of 35-40 subunits of two different αA- and αB-subunits, each of 20kDa. The β/γ-crystallin superfamily comprises oligomeric β-crystallin (2-6 subunits) and monomeric γ-crystallin. Since lens proteins have very long half-lives, they undergo numerous post-translational modifications including racemization, isomerization, deamidation, oxidation, glycation, and truncation, which may decrease crystallin solubility and ultimately cause cataract formation. Racemization and isomerization of aspartyl (Asp) residues have been detected only in polymeric α- and oligomeric β-crystallin, while the situation in monomeric γ-crystallin has not been studied. Here, we investigated the racemization and isomerization of Asp in the γ-crystallin fraction of elderly donors. The results show that Asp residues of γS-, γD- and γC-crystallins were not racemized and isomerized. However, strikingly, we found that a portion of αB-crystallin and βA3-crystallin moved to the lower molecular weight fraction which is the same size of γ-crystallin. In those fractions, Asp-96 of αB-crystallin and Asp-37 of βA3-crystallin were highly inverted, which do not occur in the native lens higher molecular weight fraction. Our results indicate the possibility that the inversion of Asp residues may induce dissociation of αB- and βA3-crystallins from the polymeric and oligomeric states. This is the first report that stereoinversion of amino acids disturbs lens protein assembly in aged human lens. Copyright © 2014 Elsevier B.V. All rights reserved.

Analysis of cholera toxin-ganglioside interactions by flow cytometry.

PubMed

Lauer, Sabine; Goldstein, Byron; Nolan, Rhiannon L; Nolan, John P

2002-02-12

Cholera toxin entry into mammalian cells is mediated by binding of the pentameric B subunit (CTB) to ganglioside GM(1) in the cell membrane. We used flow cytometry to quantitatively measure in real time the interactions of fluorescently labeled pentameric cholera toxin B-subunit (FITC-CTB) with its ganglioside receptor on microsphere-supported phospholipid membranes. A model that describes the multiple steps of this mode of recognition was developed to guide our flow cytometric experiments and extract relevant equilibrium and kinetic rate constants. In contrast to previous studies, our approach takes into account receptor cross-linking, an important feature for multivalent interactions. From equilibrium measurements, we determined an equilibrium binding constant for a single subunit of FITC-CTB binding monovalently to GM(1) presented in bilayers of approximately 8 x 10(7) M(-1) while that for binding to soluble GM(1)-pentasaccharide was found to be approximately 4 x 10(6) M(-1). From kinetic measurements, we determined the rate constant for dissociation of a single site of FITC-CTB from microsphere-supported bilayers to be (3.21 +/- 0.03) x 10(-3) s(-1), and the rate of association of a site on FITC-CTB in solution to a GM(1) in the bilayer to be (2.8 +/- 0.4) x 10(4) M(-1) s(-1). These values yield a lower estimate for the equilibrium binding constant of approximately 1 x 10(7) M(-1). We determined the equilibrium surface cross-linking constant [(1.1 +/- 0.1) x 10(-12) cm(2)] and from this value and the value for the rate constant for dissociation derived a value of approximately 3.5 x 10(-15) cm(2) s(-1) for the forward rate constant for cross-linking. We also compared the interaction of the receptor binding B-subunit with that of the whole toxin (A- and B-subunits). Our results show that the whole toxin binds with approximately 100-fold higher avidity than the pentameric B-subunit alone which is most likely due to the additional interaction of the A(2)-subunit with the membrane surface. Interaction of cholera toxin B-subunit and whole cholera toxin with gangliosides other than GM(1) revealed specific binding only to GD1(b) and asialo-GM(1). These interactions, however, are marked by low avidity and require high receptor concentrations to be observed.

Initial bridges between two ribosomal subunits are formed within 9.4 milliseconds, as studied by time-resolved cryo-EM.

PubMed

Shaikh, Tanvir R; Yassin, Aymen S; Lu, Zonghuan; Barnard, David; Meng, Xing; Lu, Toh-Ming; Wagenknecht, Terence; Agrawal, Rajendra K

2014-07-08

Association of the two ribosomal subunits during the process of translation initiation is a crucial step of protein synthesis. The two subunits (30S and 50S) of the bacterial 70S ribosome are held together by 12 dynamic bridges involving RNA-RNA, RNA-protein, and protein-protein interactions. The process of bridge formation, such as whether all these bridges are formed simultaneously or in a sequential order, is poorly understood. To understand such processes, we have developed and implemented a class of microfluidic devices that mix two components to completion within 0.4 ms and spray the mixture in the form of microdroplets onto an electron microscopy grid, yielding a minimum reaction time of 9.4 ms before cryofixation. Using these devices, we have obtained cryo-EM data corresponding to reaction times of 9.4 and 43 ms and have determined 3D structures of ribosomal subunit association intermediates. Molecular analyses of the cryo-EM maps reveal that eight intersubunit bridges (bridges B1a, B1b, B2a, B2b, B3, B7a, B7b, and B8) form within 9.4 ms, whereas the remaining four bridges (bridges B2c, B4, B5, and B6) take longer than 43 ms to form, suggesting that bridges are formed in a stepwise fashion. Our approach can be used to characterize sequences of various dynamic functional events on complex macromolecular assemblies such as ribosomes.

Effect of Cavβ Subunits on Structural Organization of Cav1.2 Calcium Channels

PubMed Central

Duong, Son Q.; Thomas, Sam; Harry, Jo Beth; Patel, Chirag; Lao, Qi Zong; Soldatov, Nikolai M.

2009-01-01

Background Voltage-gated Cav1.2 calcium channels play a crucial role in Ca2+ signaling. The pore-forming α1C subunit is regulated by accessory Cavβ subunits, cytoplasmic proteins of various size encoded by four different genes (Cavβ1 - β4) and expressed in a tissue-specific manner. Methods and Results Here we investigated the effect of three major Cavβ types, β1b, β2d and β3, on the structure of Cav1.2 in the plasma membrane of live cells. Total internal reflection fluorescence microscopy showed that the tendency of Cav1.2 to form clusters depends on the type of the Cavβ subunit present. The highest density of Cav1.2 clusters in the plasma membrane and the smallest cluster size were observed with neuronal/cardiac β1b present. Cav1.2 channels containing β3, the predominant Cavβ subunit of vascular smooth muscle cells, were organized in a significantly smaller number of larger clusters. The inter- and intramolecular distances between α1C and Cavβ in the plasma membrane of live cells were measured by three-color FRET microscopy. The results confirm that the proximity of Cav1.2 channels in the plasma membrane depends on the Cavβ type. The presence of different Cavβ subunits does not result in significant differences in the intramolecular distance between the termini of α1C, but significantly affects the distance between the termini of neighbor α1C subunits, which varies from 67 Å with β1b to 79 Å with β3. Conclusions Thus, our results show that the structural organization of Cav1.2 channels in the plasma membrane depends on the type of Cavβ subunits present. PMID:19492014

Assembly of the stator in Escherichia coli ATP synthase. Complexation of alpha subunit with other F1 subunits is prerequisite for delta subunit binding to the N-terminal region of alpha

PubMed Central

Senior, Alan E.; Muharemagi, Alma; Wilke-Mounts, Susan

2008-01-01

Alpha subunit of Escherichia coli ATP synthase was expressed with a C-terminal 6-His tag and purified. Pure alpha was monomeric, competent in nucleotide binding, and had normal N-terminal sequence. In F1-subunit dissociation/reassociation experiments it supported full reconstitution of ATPase, and reassociated complexes were able to bind to F1-depleted membranes with restoration of ATP-driven proton pumping. Therefore interaction between the stator delta subunit and the N-terminal residue 1-22 region of alpha occurred normally when pure alpha was complexed with other F1 subunits. On the other hand, three different types of experiment showed that no interaction occurred between pure delta and isolated alpha subunit. Unlike in F1, the N-terminal region of isolated alpha was not susceptible to trypsin cleavage. Therefore, during assembly of ATP synthase, complexation of alpha subunit with other F1 subunits is prerequisite for delta subunit binding to the N-terminal region of alpha. We suggest that the N-terminal 1-22 residues of alpha are sequestered in isolated alpha until released by binding of beta to alpha subunit. This prevents 1/1 delta/alpha complexes from forming, and provides a satisfactory explanation of the stoichiometry of one delta per three alpha seen in the F1 sector of ATP synthase, assuming that steric hindrance prevents binding of more than one delta to the alpha3/beta3 hexagon. The cytoplasmic fragment of the b subunit (bsol) did not bind to isolated alpha. It might also be that complexation of alpha with beta subunits is prerequisite for direct binding of stator b subunit to the F1-sector. PMID:17176112

Association between the NMDA glutamate receptor GRIN2B gene and obsessive–compulsive disorder

PubMed Central

Alonso, Pino; Gratacós, Mónica; Segalàs, Cinto; Escaramís, Georgia; Real, Eva; Bayés, Mónica; Labad, Javier; López-Solà, Clara; Estivill, Xavier; Menchón, José M.

2012-01-01

Background Recent data from neuroimaging, genetic and clinical trials and animal models suggest a role for altered glutamatergic neurotransmission in the pathogenesis of obsessive–compulsive disorder (OCD). The aim of this study was to investigate whether variants in the GRIN2B gene, the gene encoding the NR2 subunit of the N-methyl-d-aspartate (NMDA) glutamate receptor, may contribute to genetic susceptibility to OCD or to different OCD subphenotypes. Methods Between 2003 and 2008, we performed a case–control association study in which we genotyped 10 tag single-nucleotide polymorphisms (SNPs) in the 3′ untranslated region (3′ UTR) of GRIN2B. We performed SNP association and haplotype analysis considering the OCD diagnosis and different OCD subphenotypes: early-onset OCD, comorbid tic disorders and OCD clinical symptom dimensions. Results We enrolled 225 patients with OCD and 279 controls recruited from the OCD Clinic at Bellvitge Hospital (Barcelona, Spain). No significant difference in the distribution of alleles or genotypes was detected between patients with OCD and controls. Nonetheless, on analyzing OCD subphenotypes, the rs1805476 SNP in male patients (95% confidence interval [CI] 1.37–4.22, p = 0.002) and a 4-SNP haplotype in the whole sample (rs1805476, rs1805501, rs1805502 and rs1805477; odds ratio 1.92, 95% CI 1.22–3.01; permutation p = 0.023) were significantly associated with the presence of contamination obsessions and cleaning compulsions. Limitations Study limitations included the risk of population stratification associated with the case–control design, use of psychiatrically unscreened blood donors as the control group, reduced sample size of participants with certain OCD subphenotypes and tested polymorphisms limited to 3′ UTR and exon 13 of GRIN2B. Conclusion Our results converge with recent data suggesting a possible contribution of glutamatergic variants to the genetic vulnerability to OCD or at least to certain OCD manifestations. The dissection of OCD into more homogeneous subphenotypes may constitute a useful tool to disentangle the complex genetic basis of the disorder. PMID:22433450

The 3.2 Angstrom Resolution Structure of the Polymorphic Cowpea Chlorotic Mottle Virus Ribonucleoprotein Particle

NASA Astrophysics Data System (ADS)

Speir, Jeffrey Alan

Structural studies of the polymorphic cowpea chlorotic mottle virus have resulted in high resolution structures for two distinct icosahedral ribonucleoprotein particle conformations dependent upon whether acidic or basic pH conditions prevail. CCMV is stable below pH 6.5, however metal-free particles maintain a 10% increase in hydrodynamic volume at pH >=q 7.5. Identification of this swollen' form of CCMV, which can easily be disrupted with 1M NaCl, led to the first reassembly of an icosahedral virus in vitro from purified viral protein and RNA to form infectious particles, and its assembly has been the subject of biochemical and biophysical investigations for over twenty-five years. Under well defined conditions of pH, ionic strength and divalent metal ion concentration, CCMV capsid protein or capsid protein and RNA will reassemble to form icosahedral particles of various sizes, sheets, tubes, rosettes, and a variety of laminar structures which resemble virion structures from non-related virus families. Analysis of native particles at 3.2A resolution and swollen particles at 28A resolution has suggested that the chemical basis for the formation of polymorphic icosahedral and anisometric structures is: (i) hexamers formed of beta-barrel subunits stabilized by an unusual hexameric parallel beta structure made up of their N-termini, (ii) the location of protein-RNA interactions, (iii) divalent metal cation binding sites that regulate quasi-symmetrical subunit associations, (iv) charge repulsion across the same interfaces when lacking divalent metal ions at basic pH, which induces the formation of sixty 20A diameter portals for RNA release, and (v) a novel, C-terminal-based, subunit dimer assembly unit. The use of C- and N-terminal arms in CCMV has not been observed in other icosahedral RNA virus structures determined at near atomic resolution, however, their detailed interactions and roles in stabilizing the quaternary organization of CCMV are related to that found in the atomic structures of the DNA tumor papovaviruses (SV40 and polyoma). The swollen structure is closely similar to the expanded form of tomato bushy stunt virus (TBSV) previously determined at 8A resolution by X-ray crystallography.

Escherichia coli F1Fo-ATP synthase with a b/δ fusion protein allows analysis of the function of the individual b subunits.

PubMed

Gajadeera, Chathurada S; Weber, Joachim

2013-09-13

The "stator stalk" of F1Fo-ATP synthase is essential for rotational catalysis as it connects the nonrotating portions of the enzyme. In Escherichia coli, the stator stalk consists of two (identical) b subunits and the δ subunit. In mycobacteria, one of the b subunits and the δ subunit are replaced by a b/δ fusion protein; the remaining b subunit is of the shorter b' type. In the present study, it is shown that it is possible to generate a functional E. coli ATP synthase containing a b/δ fusion protein. This construct allowed the analysis of the roles of the individual b subunits. The full-length b subunit (which in this case is covalently linked to δ in the fusion protein) is responsible for connecting the stalk to the catalytic F1 subcomplex. It is not required for interaction with the membrane-embedded Fo subcomplex, as its transmembrane helix can be removed. Attachment to Fo is the function of the other b subunit which in turn has only a minor (if any at all) role in binding to δ. Also in E. coli the second b subunit can be shortened to a b' type.

Binding of ATP by pertussis toxin and isolated toxin subunits

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hausman, S.Z.; Manclark, C.R.; Burns, D.L.

1990-07-03

The binding of ATP to pertussis toxin and its components, the A subunit and B oligomer, was investigated. Whereas, radiolabeled ATP bound to the B oligomer and pertussis toxin, no binding to the A subunit was observed. The binding of ({sup 3}H)ATP to pertussis toxin and the B oligomer was inhibited by nucleotides. The relative effectiveness of the nucleotides was shown to be ATP > GTP > CTP > TTP for pertussis toxin and ATP > GTP > TTP > CTP for the B oligomer. Phosphate ions inhibited the binding of ({sup 3}H)ATP to pertussis toxin in a competitive manner;more » however, the presence of phosphate ions was essential for binding of ATP to the B oligomer. The toxin substrate, NAD, did not affect the binding of ({sup 3}H)ATP to pertussis toxin, although the glycoprotein fetuin significantly decreased binding. These results suggest that the binding site for ATP is located on the B oligomer and is distinct from the enzymatically active site but may be located near the eukaryotic receptor binding site.« less

Single nucleotide polymorphisms of the bovine VEGF-B gene and their associations with growth traits in the Nanyang cattle breed.

PubMed

Pang, Y H; Lei, C Z; Zhang, C L; Lan, X Y; Shao, S M; Gao, X M; Chen, H

2012-01-01

PCR-SSCP and DNA sequencing methods were applied to reveal single nucleotide polymorphisms (SNPs) in the bovine VEGF-B gene in 675 samples belonging to three native Chinese cattle breeds. We found 3 SNPs and a duplication NC_007330.5: g. [782 A>G p. (Gly112 =) (;) 1000-1001dup CT (;) 1079 C>T (;) 2129 G>A p. (Arg184Gln)]. We also observed a statistically significant association of the polymorphism (1000-1001dup CT) in intron 3 of the VEGF-B gene with the body weight of the Nanyang cattle (p < 0.05). This polymorphisms of VEGF-B gene need to be verified among a larger cattle population before it can be identified as a marker for bovine body weight.

High conservation of herpes simplex virus UL5/UL52 helicase-primase complex in the era of new antiviral therapies.

PubMed

Collot, Marianne; Rouard, Caroline; Brunet, Christel; Agut, Henri; Boutolleau, David; Burrel, Sonia

2016-04-01

The emergence of herpes simplex virus (HSV) resistance to current antiviral drugs, that all target the viral DNA polymerase, constitutes a major obstacle to antiviral treatment effectiveness of HSV infections, especially in immunocompromised patients. A novel and promising class of inhibitors of the HSV UL5/UL52 helicase-primase (HP) complex has been reported to hinder viral replication with a high potency. In this study, we describe the low natural polymorphism (interstrain identity >99.1% at both nucleotide and amino acid levels) of HSV HP complex subunits pUL5 and pUL52 among 64 HSV (32 HSV-1 and 32 HSV-2) clinical isolates, and we show that the HSV resistance profile to the first-line antiviral drug acyclovir (ACV) does not impact on the natural polymorphism of HSV HP complex. Genotypic tools and polymorphism data concerning HSV HP complex provided herein will be useful to detect drug resistance mutations in a relevant time frame when HP inhibitors (HPIs), i.e., amenamevir and pritelivir, will be available in medical practice. Copyright © 2016 Elsevier B.V. All rights reserved.

The cyanobacterial cytochrome b6f subunit PetP adopts an SH3 fold in solution.

PubMed

Veit, Sebastian; Nagadoi, Aritaka; Rögner, Matthias; Rexroth, Sascha; Stoll, Raphael; Ikegami, Takahisa

2016-06-01

PetP is a peripheral subunit of the cytochrome b(6)f complex (b(6)f) present in both, cyanobacteria and red algae. It is bound to the cytoplasmic surface of this membrane protein complex where it greatly affects the efficiency of the linear photosynthetic electron flow although it is not directly involved in the electron transfer reactions. Despite the crystal structures of the b(6)f core complex, structural information for the transient regulatory b(6)f subunits is still missing. Here we present the first structure of PetP at atomic resolution as determined by solution NMR. The protein adopts an SH3 fold, which is a common protein motif in eukaryotes but comparatively rare in prokaryotes. The structure of PetP enabled the identification of the potential interaction site for b(6)f binding by conservation mapping. The interaction surface is mainly formed by two large loop regions and one short 310 helix which also exhibit an increased flexibility as indicated by heteronuclear steady-state {(1)H}-(15)N NOE and random coil index parameters. The properties of this potential b(6)f binding site greatly differ from the canonical peptide binding site which is highly conserved in eukaryotic SH3 domains. Interestingly, three other proteins of the photosynthetic electron transport chain share this SH3 fold with PetP: NdhS of the photosynthetic NADH dehydrogenase-like complex (NDH-1), PsaE of the photosystem 1 and subunit α of the ferredoxin-thioredoxin reductase have, similar to PetP, a great impact on the photosynthetic electron transport. Finally, a model is presented to illustrate how SH3 domains modulate the photosynthetic electron transport processes in cyanobacteria. Copyright © 2016 Elsevier B.V. All rights reserved.

Isolation and characterization of a presynaptic neurotoxin, P-elapitoxin-Bf1a from Malaysian Bungarus fasciatus venom.

PubMed

Rusmili, Muhamad Rusdi Ahmad; Yee, Tee Ting; Mustafa, Mohd Rais; Hodgson, Wayne C; Othman, Iekhsan

2014-10-01

Presynaptic neurotoxins are one of the major components in Bungarus venom. Unlike other Bungarus species that have been studied, β-bungarotoxin has never been isolated from Bungarus fasciatus venom. It was hypothesized that the absence of β-bungarotoxin in this species was due to divergence during evolution prior to evolution of β-bungarotoxin. In this study, we have isolated a β-bungarotoxin isoform we named P-elapitoxin-Bf1a by using gel filtration, cation-exchange and reverse-phase chromatography from Malaysian B. fasciatus venom. The toxin consists of two heterogeneous subunits, subunit A and subunit B. LCMS/MS data showed that subunit A was homologous to acidic phospholipase A2 subunit A3 from Bungarus candidus and B. multicinctus venoms, whereas subunit B was homologous with subunit B1 from B. fasciatus venom that was previously detected by cDNA cloning. The toxin showed concentration- and time-dependent reduction of indirect-twitches without affecting contractile responses to ACh, CCh or KCl at the end of experiment in the chick biventer preparation. Toxin modification with 4-BPB inhibited the neurotoxic effect suggesting the importance of His-48. Tissue pre-incubation with monovalent B. fasciatus (BFAV) or neuro-polyvalent antivenom (NPV), at the recommended titer, was unable to inhibit the twitch reduction induced by the toxin. This study indicates that Malaysian B. fasciatus venom has a unique β-bungarotoxin isoform which was not neutralized by antivenoms. This suggests that there might be other presynaptic neurotoxins present in the venom and there is a variation in the enzymatic neurotoxin composition in venoms from different localities. Copyright © 2014 Elsevier Inc. All rights reserved.

MUC1 and MUC4: Switching the Emphasis from Large to Small

PubMed Central

Carraway, Kermit L.

2011-01-01

Summation The MUC1 and MUC4 membrane mucins are each composed of a large alpha (α) and a small beta (β) subunit. The α subunits are fully exposed at the cell surface and contain variable numbers of repeated amino acid sequences that are heavily glycosylated. In contrast, the β subunits are much smaller and are anchored within the cell membrane, with their amino-terminal portions exposed at the cell surface and their carboxy-terminal tails facing the cytosol. Studies over the last several years are challenging the long-held belief that α subunits play the predominant role in cancer by conferring cellular properties that allow tumor cells to evade immune recognition and destruction. Indeed, the β subunits of MUC1 and MUC4 have emerged as oncogenes, as they engage signaling pathways responsible for tumor initiation and progression. Thus, a switch in the emphasis from the large α to the small β subunits offers attractive possibilities for successful clinical application. Such a focus shift is further supported by the absence of allelic polymorphism and variable glycosylation in the β subunit as well as by the presence of the β subunit in most MUC1 and MUC4 isoforms expressed by tumors. MUC1α, also known as CA15.3, is a Food and Drug Administration-approved serum biomarker for breast cancer, but its use is no longer recommended by the American Society of Clinical Oncology. However, comparison of β subunit expression in normal and malignant breast tissues may offer a novel approach to the exploitation of membrane mucins as biomarkers, as MUC1β-induced gene signatures with prognostic and predictive values in breast cancer have been reported. Preclinical studies with peptides that interfere with MUC1β oncogenic functions also look promising. PMID:21728842

Assembly of 4-, 6- and 8-connected Cd(II) pseudo-polymorphic coordination polymers: Synthesis, solvent-dependent structural variation and properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Zhao-Hao; Xue, Li-Ping, E-mail: lpxue@163.com; Miao, Shao-Bin

2016-08-15

The reaction of Cd(NO{sub 3}){sub 2}·4H{sub 2}O, 2,5-thiophenedicarboxylic acid (H{sub 2}tdc) and 1,2-bis(imidazol-1′-yl)methane (bimm) by modulating solvent systems yielded three highly connected pseudo-polymorphic coordination polymers based on different dinuclear [Cd{sub 2}(CO{sub 2}){sub 2}] subunits bridged by carboxylate groups. Single crystal structural analyses reveal structural variation from 4-connected 2D sql layer, 6-connected 2-fold interpenetrated 3D pcu to 8-connected 3D bcu-type network in compounds 1–3. The structural dissimilarity in the structures dependent on the coordination environments of Cd(II) ions and linking modes of mixed ligand influenced by different solvent systems during the synthesis process. Moreover, thermogravimetric and photoluminescence behaviors of 1–3 weremore » also investigated for the first time, and all the complexes emit blue luminescence in the solid state. - Graphical abstract: Key Topic. Different solvent systems modulated three Cd(II) pseudo-polymorphic coordination polymers based on thiophene-2,5-dicarboxylate and 1,2-bis(imidazol-1′-yl)methane mixed ligands. Display Omitted - Highlights: • Three solvent-dependent Cd(II) pseudo-polymorphic coordination polymers have been synthesized. • Structural variation from 4-connected 2D layer, 6-connected 2-fold interpenetrated 3D net to 8-connected 3D net. • All complexes emit blue luminescence.« less

Functional characterization of the non-catalytic ectodomains of the nucleotide pyrophosphatase/phosphodiesterase NPP1.

PubMed Central

Gijsbers, Rik; Ceulemans, Hugo; Bollen, Mathieu

2003-01-01

The ubiquitous nucleotide pyrophosphatases/phosphodiesterases NPP1-3 consist of a short intracellular N-terminal domain, a single transmembrane domain and a large extracellular part, comprising two somatomedin-B-like domains, a catalytic domain and a poorly defined C-terminal domain. We show here that the C-terminal domain of NPP1-3 is structurally related to a family of DNA/RNA non-specific endonucleases. However, none of the residues that are essential for catalysis by the endonucleases are conserved in NPP1-NPP3, suggesting that the nuclease-like domain of NPP1-3 does not represent a second catalytic domain. Truncation analysis revealed that the nuclease-like domain of NPP1 is required for protein stability, for the targeting of NPP1 to the plasma membrane and for the expression of catalytic activity. We also demonstrate that 16 conserved cysteines in the somatomedin-B-like domains of NPP1, in concert with two flanking cysteines, mediate the dimerization of NPP1. The K173Q polymorphism of NPP1, which maps to the second somatomedin-B-like domain and has been associated with the aetiology of insulin resistance, did not affect the dimerization or catalytic activity of NPP1, and did not endow NPP1 with an affinity for the insulin receptor. Our data suggest that the non-catalytic ectodomains contribute to the subunit structure, stability and function of NPP1-3. PMID:12533192

Lack of association between temporal lobe epilepsy and a novel polymorphism in the alpha 2 subunit gene (ATP1A2) of the sodium potassium transporting ATPase.

PubMed

Buono, R J; Ferraro, T N; O'Connor, M J; Sperling, M R; Abbey, M; Finanger, E; Lohoff, F; Mulholland, N; Berrettini, W H

2000-02-07

Genetic linkage studies in rodents and humans have identified specific chromosomal regions harboring seizure susceptibility genes. We have identified a novel polymorphism in the human alpha 2 subunit gene (ATP1A2) of the sodium potassium transporting ATPase (NaK-pump), a candidate gene for human temporal lobe epilepsy (TLE) based on its chromosomal location and function in ion homeostasis. The polymorphism consists of a four base pair insertion 12 base pairs upstream of the start of exon 2. We performed an association study between this polymorphism and TLE. Our study did not find a significant difference in the frequency of this polymorphism between TLE patients and controls, indicating that this variation is not a major susceptibility factor. However, since the number of patients studied so far is small and the functional consequence of the polymorphism is unknown, the variation may yet be found to play a minor role in increased risk for seizure susceptibility. In contrast to the findings in TLE patients and controls, we did find a significant difference in the frequency of the variation between African Americans and persons of European descent. This finding demonstrates the potential effect of population stratification on studies of this type and supports the growing use of parental and familial samples for controls in association studies. Further study of this polymorphism is warranted as it may be involved in other disease processes for which there are known ethnic-specific susceptibilities. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:79-83, 2000. Copyright 2000 Wiley-Liss, Inc.

Dual effects of ouabain on the regulation of proliferation and apoptosis in human umbilical vein endothelial cells: involvement of Na(+)-K(+)-ATPase α-subunits and NF-κB.

PubMed

Ren, Yan-Ping; Zhang, Ming-Juan; Zhang, Ting; Huang, Ruo-Wen

2014-01-01

To elucidate the effect of ouabain on the regulation of proliferation and apoptosis of HUVECs and involvement of different Na(+)-K(+)-ATPase α-subunits and NF-κB. HUVECs were isolated by collagenase perfusion, and MTT assays and cell cycle analysis were performed to study proliferation. NF-κB expression and function were examined by immunohistochemical staining and western blotting. Na(+)-K(+)-ATPase activity was determined by measuring released ouabain inhibitable inorganic phosphate (Pi). The expression of different α-subunits was investigated by real RT-PCR, western blotting and cell immunofluorescence. 0.3 nM ouabain treatment for 0.5 h triggered the proliferation of HUVECs, peaking at 1-2 h. At 1.8 nM for 0.5 h, ouabain induced an increase of cell proliferation for a short time, and then triggered a decrease after 1 h. Cell cycle analysis show that 37% of HUVECs were in G2/M phase of the cell cycle following incubation with 1.8 nM ouabain, compared with 18% with 0.3 nM ouabain. NF-κB activity was assessed by western blot analysis of IκB expression, which was significantly reduced with 0.3 nM ouabain treatment; there was no different between 1.8 nM ouabain treatment and untreated cells. Na(+)-K(+)-ATPase activity in HUVECs was markedly reduced after treatment with 0.3 nM and 1.8 nM ouabain. Real RT-PCR and western blotting indicated that Na(+)-K(+)-ATPase α1-subunit mRNA expression levels increased after 0.3 nM ouabain treatment and decreased after 1.8 nM ouabain treatment. However, α2- and α3-subunit mRNA decreased after 0.3 nM ouabain treatment and increased after 1.8 nM ouabain treatment. Ouabain at different concentrations caused dual effects on proliferation and apoptosis in HUVECs.

1, 25(OH){sub 2}D{sub 3}-induced interaction of vitamin D receptor with p50 subunit of NF-κB suppresses the interaction between KLF5 and p50, contributing to inhibition of LPS-induced macrophage proliferation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ma, Dong; School of Public Health, North China University of Science and Technology, Tangshan, Hebei, 063000; Zhang, Ruo-nan

KLF5 and nuclear factor κB (NF-κB) regulate cell proliferation and inflammation. Vitamin D signaling through vitamin D receptor (VDR) exerts anti-proliferative and anti-inflammatory actions. However, an actual relationship between KLF5, NF-κB and VDR in the inflammation and proliferation of macrophages is still unclear. Here, we showed that LPS and proinflammatory cytokines stimulate KLF5 gene expression in macrophages, and that 1, 25(OH){sub 2}D{sub 3} suppresses LPS-induced KLF5 expression and cell proliferation via upregulation of VDR expression. Mechanistic studies suggested that KLF5 interacts with p50 subunit of NF-κB to cooperatively induce the expressions of positive cell cycle regulators cyclin B1 and Cdk1/Cdc2more » in LPS-treated macrophages. Further studies revealed that 1, 25(OH){sub 2}D{sub 3}-induced interaction of VDR with p50 decreases LPS-induced interaction of KLF5 with p50. Collectively, we identify a novel regulatory pathway in which 1, 25(OH){sub 2}D{sub 3} induces VDR expression and promotes VDR interaction with p50 subunit of NF-κB, which in turn attenuates the association of KLF5 with p50 subunit of NF-κB and thus exerts anti-inflammatory and anti-proliferative effects on macrophages. - Highlights: • 1, 25(OH){sub 2}D{sub 3} suppresses LPS-induced KLF5 expression via upregulation of VDR expression. • KLF5 interacts with NF-κB-p50 to cooperatively induce the expressions of positive cell cycle regulators cyclin B1 and Cdk1/Cdc2 in LPS-treated macrophages. • 1,25(OH){sub 2}D{sub 3} induces interaction of VDR with p50.« less

Polymorphisms of CCL3L1/CCR5 genes and recurrence of hepatitis B in liver transplant recipients.

PubMed

Li, Hong; Xie, Hai-Yang; Zhou, Lin; Wang, Wei-Lin; Liang, Ting-Bo; Zhang, Min; Zheng, Shu-Sen

2011-12-01

The genetic diversity of chemokines and chemokine receptors has been associated with the outcome of hepatitis B virus infection. The aim of this study was to evaluate whether the copy number variation in the CCL3L1 gene and the polymorphisms of CCR5Δ32 and CCR5-2459A→G (rs1799987) are associated with recurrent hepatitis B in liver transplantation for hepatitis B virus infection-related end-stage liver disease. A total of 185 transplant recipients were enrolled in this study. The genomic DNA was extracted from whole blood, the copy number of the CCL3L1 gene was determined by a quantitative real-time PCR based assay, CCR5Δ32 was detected by a sizing PCR method, and a single-nucleotide polymorphism in CCR5-2459 was detected by restriction fragment length polymorphism PCR. No CCR5Δ32 mutation was detected in any of the individuals from China. Neither copy number variation nor polymorphism in CCR5-2459 was associated with post-transplant re-infection with hepatitis B virus. However, patients with fewer copies (<4) of the CCL3L1 gene compared with the population median in combination with the CCR5G allele had a significantly higher risk for recurrent hepatitis B (odds ratio=1.93, 95% CI: 1.00-3.69; P=0.047). Patients possessing the compound decreased functional genotype of both CCL3L1 and CCR5 genes might be more likely to have recurrence of hepatitis B after transplantation.

Ocular myasthenia gravis induced by human acetylcholine receptor ϵ subunit immunization in HLA DR3 transgenic mice.

PubMed

Wu, Xiaorong; Tuzun, Erdem; Saini, Shamsher S; Wang, Jun; Li, Jing; Aguilera-Aguirre, Leopoldo; Huda, Ruksana; Christadoss, Premkumar

2015-12-01

Extraocular muscles (EOM) are preferentially involved in myasthenia gravis (MG) and acetylcholine receptor (AChR) antibody positive MG patients may occasionally present with isolated ocular symptoms. Although experimental autoimmune myasthenia gravis (EAMG) induced by whole AChR immunization closely mimics clinical and immunopathological aspects of MG, EOM are usually not affected. We have previously developed an EAMG model, which imitates EOM symptoms of MG by immunization of human leukocyte antigen (HLA) transgenic mice with α or γ-subunits of human AChR (H-AChR). To investigate the significance of the ϵ-subunit in ocular MG, we immunized HLA-DR3 and HLA-DQ8 transgenic mice with recombinant H-AChR ϵ-subunit expressed in Escherichia coli. HLA-DR3 transgenic mice showed significantly higher clinical ocular and generalized MG severity scores and lower grip strength values than HLA-DQ8 mice. H-AChR ϵ-subunit-immunized HLA-DR3 transgenic mice had higher serum anti-AChR antibody (IgG, IgG1, IgG2b, IgG2c and IgM) levels, neuromuscular junction IgG and complement deposit percentages than ϵ-subunit-immunized HLA-DQ8 transgenic mice. Control mice immunized with E. coli extract or complete Freund adjuvant (CFA) did not show clinical and immunopathological features of ocular and generalized EAMG. Lymph node cells of ϵ-subunit-immunized HLA-DR3 mice showed significantly higher proliferative responses than those of ϵ-subunit-immunized HLA-DQ8 mice, crude E. coli extract-immunized and CFA-immunized transgenic mice. Our results indicate that the human AChR ϵ-subunit is capable of inducing myasthenic muscle weakness. Diversity of the autoimmune responses displayed by mice expressing different HLA class II molecules suggests that the interplay between HLA class II alleles and AChR subunits might have a profound impact on the clinical course of MG. Copyright © 2015 European Federation of Immunological Societies. Published by Elsevier B.V. All rights reserved.

Nmd3p Is a Crm1p-Dependent Adapter Protein for Nuclear Export of the Large Ribosomal Subunit

PubMed Central

Ho, Jennifer Hei-Ngam; Kallstrom, George; Johnson, Arlen W.

2000-01-01

In eukaryotic cells, nuclear export of nascent ribosomal subunits through the nuclear pore complex depends on the small GTPase Ran. However, neither the nuclear export signals (NESs) for the ribosomal subunits nor the receptor proteins, which recognize the NESs and mediate export of the subunits, have been identified. We showed previously that Nmd3p is an essential protein from yeast that is required for a late step in biogenesis of the large (60S) ribosomal subunit. Here, we show that Nmd3p shuttles and that deletion of the NES from Nmd3p leads to nuclear accumulation of the mutant protein, inhibition of the 60S subunit biogenesis, and inhibition of the nuclear export of 60S subunits. Moreover, the 60S subunits that accumulate in the nucleus can be coimmunoprecipitated with the NES-deficient Nmd3p. 60S subunit biogenesis and export of truncated Nmd3p were restored by the addition of an exogenous NES. To identify the export receptor for Nmd3p we show that Nmd3p shuttling and 60S export is blocked by the Crm1p-specific inhibitor leptomycin B. These results identify Crm1p as the receptor for Nmd3p export. Thus, export of the 60S subunit is mediated by the adapter protein Nmd3p in a Crm1p-dependent pathway. PMID:11086007

Relationship of HLA-B*51 and HLA-B*52 alleles and TNF-α-308A/G polymorphism with susceptibility to Takayasu arteritis: a meta-analysis.

PubMed

Chen, Si; Luan, Haixia; Li, Liubing; Zeng, Xiaoli; Wang, Tian; Li, Yongzhe; Yuan, Hui

2017-01-01

We performed a meta-analysis to determine whether combined evidence shows an association between HLA-B*51 and HLA-B*52 alleles and TNF-α-308A/G polymorphism and the susceptibility to Takayasu arteritis (TA). Relevant articles dated November 2015 were acquired from the PubMed, Embase and Cochrane databases. The number of genotypes and/or alleles for HLA-B*51 and HLA-B*52 alleles and TNF-α-308 A/G polymorphism in cases and control subjects was extracted, and statistical analysis was conducted using STATA 11.2 software. We included 20 studies with 1864 TA patients and 6973 controls. The HLA-B*52 allele was found to be associated with TA (pooled OR 3.91, 95 % CI 3.22-4.74, P < 0.0001). The meta-analysis of TNF-α-308 A/G polymorphism for the A allele vs. G allele (P = 0.006) and AA + AG vs. GG (P = 0.023) revealed a significant association with TA. However, we did not find that the HLA-B*51 allele was associated with TA. This meta-analysis demonstrated that the HLA-B*52 allele and TNF-α-308 A/G polymorphism may contribute to TA susceptibility.

Cardiolipin deficiency causes a dissociation of the b 6 c:caa 3 megacomplex in B. subtilis membranes.

PubMed

García Montes de Oca, Led Yered Jafet; Cabellos Avelar, Tecilli; Picón Garrido, Gerardo Ignacio; Chagoya-López, Alicia; González de la Vara, Luis; Delgado Buenrostro, Norma Laura; Chirino-López, Yolanda Irasema; Gómez-Lojero, Carlos; Gutiérrez-Cirlos, Emma Berta

2016-08-01

The associations among respiratory complexes in energy-transducing membranes have been established. In fact, it is known that the Gram-negative bacteria Paracoccus denitrificans and Escherichia coli have respiratory supercomplexes in their membranes. These supercomplexes are important for channeling substrates between enzymes in a metabolic pathway, and the assembly of these supercomplexes depends on the protein subunits and membrane lipids, mainly cardiolipin, which is present in both the mitochondrial inner membrane and bacterial membranes. The Gram-positive bacterium Bacillus subtilis has a branched respiratory chain, in which some complexes generate proton motive force whereas others constitute an escape valve of excess reducing power. Some peculiarities of this respiratory chain are the following: a type II NADH dehydrogenase, a unique b 6 c complex that has a b 6 type cytochrome with a covalently bound heme, and a c-type heme attached to the third subunit, which is similar to subunit IV of the photosynthetic b 6 f complex. Cytochrome c oxygen reductase (caa 3 ) contains a c-type cytochrome on subunit I. We previously showed that the b 6 c and the caa 3 complexes form a supercomplex. Both the b 6 c and the caa 3 together with the quinol oxygen reductase aa 3 generate the proton motive force in B. subtilis. In order to seek proof that this supercomplex is important for bacterial growth in aerobic conditions we compared the b 6 c: caa 3 supercomplex from wild type membranes with membranes from two mutants lacking cardiolipin. Both mutant complexes were found to have similar activity and heme content as the wild type. Clear native electrophoresis showed that mutants lacking cardiolipin had b 6 c:caa 3 supercomplexes of lower mass or even individual complexes after membrane solubilization with digitonin. The use of dodecyl maltoside revealed a more evident difference between wild-type and mutant supercomplexes. Here we provide evidence showing that cardiolipin plays a role in the stability of the b 6 c:caa 3 supercomplex in B. subtilis.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jack Preiss

Conversion of the Potato tuber ADP-glucose Pyrophopshorylase Regulatory Subunit into a Catalytic Subunit. ADP-glucose synthesis, a rate-limiting reaction in starch synthesis, is catalyzed by ADP-glucose pyrophosphorylase (ADPGlc PPase). The enzyme in plants is allosterically activated by 3-phosphoglycerate (3PGA) and inhibited by inorganic phosphate (Pi) and is composed of two subunits as a heterotetramer, a2b2. Subunit a is the catalytic subunit and subunit b is designated as the regulatory subunit.The b subunit increases the affinty of the activator for the catalytic subunit. Recent results have shown that the subunits are derived from the same ancestor subunit as the regulatory subunit canmore » be converted to a catalytically subunit via mutation of just two amino acids. Lys44 and Thr54 in the large subunit from potato tuber were converted to the homologous catalytic subunit residues, Arg33 and Lys43. The activity of the large subunit mutants cannot be readily tested with a co-expressed wild-type small (catalytic) subunit because of the intrinsic activity of the latter. We co-expressed the regulatory-subunit mutants with SmallD145N, an inactive S subunit in which the catalytic Asp145 was mutated. The activity of the small (catalytic) subunit was reduced more than three orders of magnitude. Coexpression of the L subunit double mutant LargeK44R/T54K with SmallD145N generated an enzyme with considerable activity, 10% and 18% of the wildtype enzyme, in the ADP-glucose synthetic and pyrophosphorolytic direction, respectively. Replacement of those two residues in the small subunit by the homologous amino acids in the L subunits (mutations R33K and K43T) decreased the activity one and two orders of magnitude. The wild-type enzyme and SmallD145NLargeK44R/T54K had very similar kinetic properties indicating that the substrate site has been conserved. The fact that only two mutations in the L subunit restored enzyme activity is very strong evidence that the large subunit is derived from the catalytic ancestor. Previous results showed that Asp145 in the small subunit of the wild-type is essential for catalysis, whereas the homologous Asp160 in the Large WT subunit is not. However, in this study, mutation D160N or D160E in the LK44R/T54K subunit abolished the activity, which shows the ancestral essential role of this residue and confirms that the catalysis of SmallD145NLarge K44R/T54K occurs in the L(b) subunit. A phylogenetic tree of the ADP-Glc PPases present in photosynthetic eukaryotes also sheds information about the origin of the subunits. The tree showed that plant Small and Large subunits can be divided into two and four distinct groups, respectively. The two main groups of S subunits are from dicot and monocot plants, whereas Large subunit groups correlate better with their documented tissue expression. The first Large-subunit group is generally expressed in photosynthetic tissues and comprises Large subunits from dicots and monocots. Group II displays a broader expression pattern, whereas groups III and IV are expressed in storage organs (roots, stems, tubers, seeds). Subunits from group III are only from dicot plants, whereas group IV are seed-specific subunits from monocots. These last two groups stem from the same branch of the phylogenetic tree and split before monocot and dicot separation. Thus few as two mutations turned the L subunit from Solanum tuberosum catalytic, showing that L and S subunits share a common catalytic ancestor, rather than a non-catalytic one. The L subunit evolved to have a regulatory role, lost catalytic residues more than 130 million years ago before monocots and dicots diverged, and preserved, possibly as a byproduct, the active site domain.« less

MicroRNA biogenesis pathway from the salmon louse (Caligus rogercresseyi): emerging role in delousing drug response.

PubMed

Valenzuela-Miranda, Diego; Nuñez-Acuña, Gustavo; Valenzuela-Muñoz, Valentina; Asgari, Sassan; Gallardo-Escárate, Cristian

2015-01-25

Despite the increasing evidence of the importance of microRNAs (miRNAs) in the regulation of multiple biological processes, the molecular bases supporting this regulation are still barely understood in crustaceans. Therefore, the molecular characterization and transcriptome modulation of the miRNA biogenesis pathway were evaluated in the salmon louse Caligus rogercresseyi, an ectoparasite that constitutes one of the biggest concerns for salmonid aquaculture industry. Hence, RNA-Seq analysis was conducted from six different developmental stages, and also after bioassays with delousing drugs Deltamethrin and Azamethiphos using adult individuals. In silico analysis evidenced 24 putative genes involved in the miRNA pathway such as biogenesis, transport, maturation and miRNA-target interaction. Moreover, 243 putative single nucleotide polymorphisms (SNPs) were identified, 15 of which showed non-synonym mutations. RNA-Seq analysis revealed that CCR4-Not complex subunit 3 (CNOT3) was upregulated at earlier developmental stages (nauplius I-II and copepodid), and also after the exposure to Azamethiphos, but not to Deltamethrin. In contrast, the subunit 7 (CNOT7) showed an inverse expression pattern. Different Argonaute transcripts were associated to chalimus and adult stages, revealing specific expression patterns in response to antiparasitic drugs. Our results suggest novel insights into the regulatory network of the post-transcriptional gene regulation in C. rogercresseyi mediated by miRNAs, evidencing a putative role during the ontogeny and drug response. Copyright © 2014 Elsevier B.V. All rights reserved.

Identification of nucleotides in E. coli 16S rRNA essential for ribosome subunit association.

PubMed

Pulk, Arto; Maiväli, Ulo; Remme, Jaanus

2006-05-01

The ribosome consists of two unequal subunits, which associate via numerous intersubunit contacts. Medium-resolution structural studies have led to grouping of the intersubunit contacts into 12 directly visualizable intersubunit bridges. Most of the intersubunit interactions involve RNA. We have used an RNA modification interference approach to determine Escherichia coli 16S rRNA positions that are essential for the association of functionally active 70S ribosomes. Modification of the N1 position of A702, A1418, and A1483 with DMS, and of the N3 position of U793, U1414, and U1495 with CMCT in 30S subunits strongly interferes with 70S ribosome formation. Five of these positions localize into previously recognized intersubunit bridges, namely, B2a (U1495), B2b (U793), B3 (A1483), B5 (A1418), and B7a (A702). The remaining position displaying interference, U1414, forms a base pair with G1486, which is a part of bridge B3. We contend that these five intersubunit bridges are essential for reassociation of the 70S ribosome, thus forming the functional core of the intersubunit contacts.

Identification of nucleotides in E. coli 16S rRNA essential for ribosome subunit association

PubMed Central

Pulk, Arto; Maiväli, Ülo; Remme, Jaanus

2006-01-01

The ribosome consists of two unequal subunits, which associate via numerous intersubunit contacts. Medium-resolution structural studies have led to grouping of the intersubunit contacts into 12 directly visualizable intersubunit bridges. Most of the intersubunit interactions involve RNA. We have used an RNA modification interference approach to determine Escherichia coli 16S rRNA positions that are essential for the association of functionally active 70S ribosomes. Modification of the N1 position of A702, A1418, and A1483 with DMS, and of the N3 position of U793, U1414, and U1495 with CMCT in 30S subunits strongly interferes with 70S ribosome formation. Five of these positions localize into previously recognized intersubunit bridges, namely, B2a (U1495), B2b (U793), B3 (A1483), B5 (A1418), and B7a (A702). The remaining position displaying interference, U1414, forms a base pair with G1486, which is a part of bridge B3. We contend that these five intersubunit bridges are essential for reassociation of the 70S ribosome, thus forming the functional core of the intersubunit contacts. PMID:16556933

A Large-Scale Genetic Association Study Confirms IL12B and Leads to the Identification of IL23R as Psoriasis-Risk Genes

PubMed Central

Cargill, Michele ; Schrodi, Steven J. ; Chang, Monica ; Garcia, Veronica E. ; Brandon, Rhonda ; Callis, Kristina P. ; Matsunami, Nori ; Ardlie, Kristin G. ; Civello, Daniel ; Catanese, Joseph J. ; Leong, Diane U. ; Panko, Jackie M. ; McAllister, Linda B. ; Hansen, Christopher B. ; Papenfuss, Jason ; Prescott, Stephen M. ; White, Thomas J. ; Leppert, Mark F. ; Krueger, Gerald G. ; Begovich, Ann B. 

2007-01-01

We performed a multitiered, case-control association study of psoriasis in three independent sample sets of white North American individuals (1,446 cases and 1,432 controls) with 25,215 genecentric single-nucleotide polymorphisms (SNPs) and found a highly significant association with an IL12B 3′-untranslated-region SNP (rs3212227), confirming the results of a small Japanese study. This SNP was significant in all three sample sets (odds ratio [OR]common 0.64, combined P [Pcomb]=7.85×10-10). A Monte Carlo simulation to address multiple testing suggests that this association is not a type I error. The coding regions of IL12B were resequenced in 96 individuals with psoriasis, and 30 additional IL12B-region SNPs were genotyped. Haplotypes were estimated, and genotype-conditioned analyses identified a second risk allele (rs6887695) located ∼60 kb upstream of the IL12B coding region that exhibited association with psoriasis after adjustment for rs3212227. Together, these two SNPs mark a common IL12B risk haplotype (ORcommon 1.40, Pcomb=8.11×10-9) and a less frequent protective haplotype (ORcommon 0.58, Pcomb=5.65×10-12), which were statistically significant in all three studies. Since IL12B encodes the common IL-12p40 subunit of IL-12 and IL-23, we individually genotyped 17 SNPs in the genes encoding the other chains of these cytokines (IL12A and IL23A) and their receptors (IL12RB1, IL12RB2, and IL23R). Haplotype analyses identified two IL23R missense SNPs that together mark a common psoriasis-associated haplotype in all three studies (ORcommon 1.44, Pcomb=3.13×10-6). Individuals homozygous for both the IL12B and the IL23R predisposing haplotypes have an increased risk of disease (ORcommon 1.66, Pcomb=1.33×10-8). These data, and the previous observation that administration of an antibody specific for the IL-12p40 subunit to patients with psoriasis is highly efficacious, suggest that these genes play a fundamental role in psoriasis pathogenesis. PMID:17236132

THE PRESENCE OF A B SUBUNIT INCREASES SENSITIVITY OF SODIUM CHANNEL NAV1.3, BUT NOT NAV1.2, TO TYPE II PYRETHROIDS.

EPA Science Inventory

Voltage-sensitive sodium channels (VSSCs) are a primary target of pyrethroid insecticides. VSSCs are comprised of a pore-forming ¿ and auxillary ß subunits, and multiple isoforms of both subunit types exist. The sensitivity of different isoform combinations to pyrethroids has not...

DNA sequences, recombinant DNA molecules and processes for producing the A and B subunits of cholera toxin and preparations containing so-obtained subunit or subunits

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harford, N.; De Wilde, M.

1987-05-19

A recombinant DNA molecule is described comprising at least a portion coding for subunits A and B of cholera toxin, or a fragment or derivative of the portion wherein the fragment or derivative codes for a polypeptide have an activity which can induce an immune response to subunit A; can induce an immune response to subunit A and cause epithelial cell penetration and the enzymatic effect leading to net loss of fluid into the gut lumen; can bind to the membrane receptor for the B subunit of cholera toxin; can induce an immune response to subunit B; can induce anmore » immune response to subunit B and bind to the membrane receptor; or has a combination of the activities.« less

h5-HT(1B) receptor-mediated constitutive Galphai3-protein activation in stably transfected Chinese hamster ovary cells: an antibody capture assay reveals protean efficacy of 5-HT.

PubMed

Newman-Tancredi, Adrian; Cussac, Didier; Marini, Laetitia; Touzard, Manuelle; Millan, Mark J

2003-03-01

1. Serotonin 5-HT(1B) receptors couple to G-proteins of the Gi/o family. However, their activation of specific G-protein subtypes is poorly characterised. Using an innovative antibody capture/guanosine-5'-0-(3-[(35)S]thio)-triphosphate ([(35)S]GTPgammaS) binding strategy, we characterised Galpha(i3) subunit activation by h5-HT(1B) receptors stably expressed in Chinese hamster ovary (CHO) cells. 2. The agonists, 5-HT, alniditan and BMS181,101, stimulated Galpha(i3), whereas methiothepin and SB224,289 behaved as inverse agonists. The selective 5-HT(1B) receptor ligand, S18127, modestly stimulated Galpha(i3) and reversed the actions of both 5-HT and methiothepin. S18127 (1 micro M) also produced parallel, dextral shifts of the 5-HT and methiothepin isotherms. 3. Isotopic dilution experiments ([(35)S]GTPgammaS versus GTPgammaS) revealed high-affinity [(35)S]GTPgammaS binding to Galpha(i3) subunits in the absence of receptor ligands indicating constitutive activity. High-affinity [(35)S]GTPgammaS binding was increased 2.8-fold by 5-HT with an increase in the affinity of GTPgammaS for Galpha(i3) subunits. In contrast, methiothepin halved the number of high-affinity binding sites and decreased their affinity. 4. h5-HT(1B) receptor-mediated Galpha(i3) subunit activation was dependent on the concentration of NaCl. At 300 mM, 5-HT stimulated [(35)S]GTPgammaS binding, basal Galpha(i3) activation was low and methiothepin was inactive. In contrast, at 10 mM NaCl, basal activity was enhanced and the inverse agonist activity of methiothepin was accentuated. Under these conditions, 5-HT decreased Galpha(i3) activation. 5. In conclusion, at h5-HT(1B) receptors expressed in CHO cells: (i) inverse agonist induced inhibition of Galpha(i3), and its reversal by S18127, reveals constitutive activation of this Galpha subunit; (ii) constitutive Galpha(i3) activation can be quantified by isotopic dilution [(35)S]GTPgammaS binding and (iii) decreasing NaCl concentrations enhances Galpha(i3) activation and leads to protean agonist properties of 5-HT: that is a switch to inhibition of Galpha(i3).

Myxovirus resistance, osteopontin and suppressor of cytokine signaling 3 polymorphisms predict hepatitis C virus therapy response in an admixed patient population: comparison with IL28B.

PubMed

Angelo, Ana Luiza Dias; Cavalcante, Lourianne Nascimento; Abe-Sandes, Kiyoko; Machado, Taísa Bonfim; Lemaire, Denise Carneiro; Malta, Fernanda; Pinho, João Renato; Lyra, Luiz Guilherme Costa; Lyra, Andre Castro

2013-10-01

Suppressor of cytokine signaling 3, myxovirus resistance protein and osteopontin gene polymorphisms may influence the therapeutic response in patients with chronic hepatitis C, and an association with IL28 might increase the power to predict sustained virologic response. Our aims were to evaluate the association between myxovirus resistance protein, osteopontin and suppressor of cytokine signaling 3 gene polymorphisms in combination with IL28B and to assess the therapy response in hepatitis C patients treated with pegylated-interferon plus ribavirin. Myxovirus resistance protein, osteopontin, suppressor of cytokine signaling 3 and IL28B polymorphisms were analyzed by PCR-restriction fragment length polymorphism, direct sequencing and real-time PCR. Ancestry was determined using genetic markers. We analyzed 181 individuals, including 52 who were sustained virologic responders. The protective genotype frequencies among the sustained virologic response group were as follows: the G/G suppressor of cytokine signaling 3 (rs4969170) (62.2%); T/T osteopontin (rs2853744) (60%); T/T osteopontin (rs11730582) (64.3%); and the G/T myxovirus resistance protein (rs2071430) genotype (54%). The patients who had ≥3 of the protective genotypes from the myxovirus resistance protein, the suppressor of cytokine signaling 3 and osteopontin had a greater than 90% probability of achieving a sustained response (p<0.0001). The C/C IL28B genotype was present in 58.8% of the subjects in this group. The sustained virological response rates increased to 85.7% and 91.7% by analyzing C/C IL28B with the T/T osteopontin genotype at rs11730582 and the G/G suppressor of cytokine signaling 3 genotype, respectively. Genetic ancestry analysis revealed an admixed population. Hepatitis C genotype 1 patients who were responders to interferon-based therapy had a high frequency of multiple protective polymorphisms in the myxovirus resistance protein, osteopontin and suppressor of cytokine signaling 3 genes. The combined analysis of the suppressor of cytokine signaling 3 and IL28B genotypes more effectively predicted sustained virologic response than IL28B analysis alone.

New data on epizootiology and genetics of piroplasms based on sequences of small ribosomal subunit and cytochrome b genes.

PubMed

Criado, A; Martinez, J; Buling, A; Barba, J C; Merino, S; Jefferies, R; Irwin, P J

2006-12-20

As a continuation of our studies on molecular epizootiology of piroplasmosis in Spain and other countries, we present in this contribution the finding of new hosts for some piroplasms, as well as information on their 18S rRNA gene sequences. Genetic data were complemented with sequences of apocytochrome b gene (whenever possible). The following conclusions were drawn from these molecular studies: Theileria annulata is capable of infecting dogs, since it was diagnosed in a symptomatic animal. According to cytochrome b sequences, isolates from cows and dog present slight differences. The same isolates showed, however, identical sequence in the 18S rRNA gene. This exemplifies well the usefulness of the mitochondrial gene for examining infra-specific variation. Babesia bovis is an occasional parasite of equines, since it was detected in two symptomatic horses. We found evidence of genetic polymorphism occurring in the 18S rRNA gene of Spanish T. equi-like and B. ovis isolates. B. bennetti from Spanish seagull is loosely related to B. ovis, and might represent a genetically distinct branch of babesids. A partial sequence of a cytochrome b pseudogene was obtained for the first time in Babesia canis rossi from South Africa. The pseudogene is distantly related to B. bigemina cytochrome b gene. These new findings confirm the ability of some piroplasms to infect multiple hosts, as well as the existence of a relatively wide genetic polymorphisms with respect to the cytochrome b gene. On the other hand, the existence of mtDNA-like pseudogenes of possible nuclear location in piroplasms is interesting due to their possible impact on molecular phylogeny studies.

h5-HT1B receptor-mediated constitutive Gαi3-protein activation in stably transfected Chinese hamster ovary cells: an antibody capture assay reveals protean efficacy of 5-HT

PubMed Central

Newman-Tancredi, Adrian; Cussac, Didier; Marini, Laetitia; Touzard, Manuelle; Millan, Mark J

2003-01-01

Serotonin 5-HT1B receptors couple to G-proteins of the Gi/o family. However, their activation of specific G-protein subtypes is poorly characterised. Using an innovative antibody capture/guanosine-5′-0-(3-[35S]thio)-triphosphate ([35S]GTPγS) binding strategy, we characterised Gαi3 subunit activation by h5-HT1B receptors stably expressed in Chinese hamster ovary (CHO) cells. The agonists, 5-HT, alniditan and BMS181,101, stimulated Gαi3, whereas methiothepin and SB224,289 behaved as inverse agonists. The selective 5-HT1B receptor ligand, S18127, modestly stimulated Gαi3 and reversed the actions of both 5-HT and methiothepin. S18127 (1 μM) also produced parallel, dextral shifts of the 5-HT and methiothepin isotherms. Isotopic dilution experiments ([35S]GTPγS versus GTPγS) revealed high-affinity [35S]GTPγS binding to Gαi3 subunits in the absence of receptor ligands indicating constitutive activity. High-affinity [35S]GTPγS binding was increased 2.8-fold by 5-HT with an increase in the affinity of GTPγS for Gαi3 subunits. In contrast, methiothepin halved the number of high-affinity binding sites and decreased their affinity. h5-HT1B receptor-mediated Gαi3 subunit activation was dependent on the concentration of NaCl. At 300 mM, 5-HT stimulated [35S]GTPγS binding, basal Gαi3 activation was low and methiothepin was inactive. In contrast, at 10 mM NaCl, basal activity was enhanced and the inverse agonist activity of methiothepin was accentuated. Under these conditions, 5-HT decreased Gαi3 activation. In conclusion, at h5-HT1B receptors expressed in CHO cells: (i) inverse agonist induced inhibition of Gαi3, and its reversal by S18127, reveals constitutive activation of this Gα subunit; (ii) constitutive Gαi3 activation can be quantified by isotopic dilution [35S]GTPγS binding and (iii) decreasing NaCl concentrations enhances Gαi3 activation and leads to protean agonist properties of 5-HT: that is a switch to inhibition of Gαi3. PMID:12684263

Dissociation of Multisubunit Protein-Ligand Complexes in the Gas Phase. Evidence for Ligand Migration

NASA Astrophysics Data System (ADS)

Zhang, Yixuan; Deng, Lu; Kitova, Elena N.; Klassen, John S.

2013-10-01

The results of collision-induced dissociation (CID) experiments performed on gaseous protonated and deprotonated ions of complexes of cholera toxin B subunit homopentamer (CTB5) with the pentasaccharide (β-D-Gal p-(1→3)-β-D-Gal pNAc-(1→4)[α-D-Neu5Ac-(2→3)]-β-D-Gal p-(1→4)-β-D-Glc p (GM1)) and corresponding glycosphingolipid (β-D-Gal p-(1→3)-β-D-Gal pNAc-(1→4)[α-D-Neu5Ac-(2→3)]-β-D-Gal p-(1→4)-β-D-Glc p-Cer (GM1-Cer)) ligands, and the homotetramer streptavidin (S4) with biotin (B) and 1,2-dipalmitoyl- sn-glycero-3-phosphoethanolamine-N-(biotinyl) (Btl), are reported. The protonated (CTB5 + 5GM1)n+ ions dissociated predominantly by the loss of a single subunit, with the concomitant migration of ligand to another subunit. The simultaneous loss of ligand and subunit was observed as a minor pathway. In contrast, the deprotonated (CTB5 + 5GM1)n- ions dissociated preferentially by the loss of deprotonated ligand; the loss of ligand-bound and ligand-free subunit were minor pathways. The presence of ceramide (Cer) promoted ligand migration and the loss of subunit. The main dissociation pathway for the protonated and deprotonated (S4 + 4B)n+/- ions, as well as for deprotonated (S4 + 4Btl)n- ions, was loss of the ligand. However, subunit loss from the (S4 + 4B)n+ ions was observed as a minor pathway. The (S4 + 4Btl)n+ ions dissociated predominantly by the loss of free and ligand-bound subunit. The charge state of the complex and the collision energy were found to have little effect on the relative contribution of the different dissociation channels. Thermally-driven ligand migration between subunits was captured in the results of molecular dynamics simulations performed on protonated (CTB5 + 5GM1)15+ ions (with a range of charge configurations) at 800 K. Notably, the migration pathway was found to be highly dependent on the charge configuration of the ion. The main conclusion of this study is that the dissociation pathways of multisubunit protein-ligand complexes in the gas phase depend, not only on the native topology of the complex, but also on structural changes that occur upon collisional activation.

Ciliary targeting of olfactory CNG channels requires the CNGB1b subunit and the kinesin-2 motor protein, KIF17.

PubMed

Jenkins, Paul M; Hurd, Toby W; Zhang, Lian; McEwen, Dyke P; Brown, R Lane; Margolis, Ben; Verhey, Kristen J; Martens, Jeffrey R

2006-06-20

Nonmotile cilia on olfactory sensory neurons (OSNs) compartmentalize signaling molecules, including odorant receptors and cyclic nucleotide-gated (CNG) channels, allowing for efficient, spatially confined responses to sensory stimuli . Little is known about the mechanisms of the ciliary targeting of olfactory CNG channels, composed of three subunits: CNGA2, CNGA4, and CNGB1b . Recent reports suggest that subunit composition of the retinal CNG channel influences localization, leading to disease . However, the mechanistic role of subunits in properly targeting native olfactory CNG channels remains unclear. Here, we show that heteromeric assembly with CNGB1b, containing a critical carboxy-terminal motif (RVxP), is required for ciliary trafficking of olfactory CNG channels. Movement of proteins within the cilia is governed by intraflagellar transport (IFT), a process that facilitates bidirectional movement of cargo along microtubules. Work in C. elegans has established that heterotrimeric and homodimeric kinesin-2 family members play a critical role in anterograde transport . In mammalian systems, the heterotrimeric KIF3a/KIF3b/KAP-3 complex plays a clear role in IFT; however, no role has been established for KIF17, the mammalian homolog of OSM-3 . Here, we demonstrate that KIF17 is required for olfactory CNG channel targeting, providing novel insights into mechanisms of mammalian ciliary transport.

Mechanisms of Size Control and Polymorphism in Viral Capsid Assembly

PubMed Central

Elrad, Oren M.; Hagan, Michael F.

2009-01-01

We simulate the assembly dynamics of icosahedral capsids from subunits that interconvert between different conformations (or quasi-equivalent states). The simulations identify mechanisms by which subunits form empty capsids with only one morphology, but adaptively assemble into different icosahedral morphologies around nanoparticle cargoes with varying sizes, as seen in recent experiments with brome mosaic virus (BMV) capsid proteins. Adaptive cargo encapsidation requires moderate cargo-subunit interaction strengths; stronger interactions frustrate assembly by stabilizing intermediates with incommensurate curvature. We compare simulation results to experiments with cowpea chlorotic mottle virus empty capsids and BMV capsids assembled on functionalized nanoparticles, and suggest new cargo encapsidation experiments. Finally, we find that both empty and templated capsids maintain the precise spatial ordering of subunit conformations seen in the crystal structure even if interactions that preserve this arrangement are favored by as little as the thermal energy, consistent with experimental observations that different subunit conformations are highly similar. PMID:18950240

Suppressor mutations identify amino acids in PAA-1/PR65 that facilitate regulatory RSA-1/B″ subunit targeting of PP2A to centrosomes in C. elegans.

PubMed

Lange, Karen I; Heinrichs, Jeffrey; Cheung, Karen; Srayko, Martin

2013-01-15

Protein phosphorylation and dephosphorylation is a key mechanism for the spatial and temporal regulation of many essential developmental processes and is especially prominent during mitosis. The multi-subunit protein phosphatase 2A (PP2A) enzyme plays an important, yet poorly characterized role in dephosphorylating proteins during mitosis. PP2As are heterotrimeric complexes comprising a catalytic, structural, and regulatory subunit. Regulatory subunits are mutually exclusive and determine subcellular localization and substrate specificity of PP2A. At least 3 different classes of regulatory subunits exist (termed B, B', B″) but there is no obvious similarity in primary sequence between these classes. Therefore, it is not known how these diverse regulatory subunits interact with the same holoenzyme to facilitate specific PP2A functions in vivo. The B″ family of regulatory subunits is the least understood because these proteins lack conserved structural domains. RSA-1 (regulator of spindle assembly) is a regulatory B″ subunit required for mitotic spindle assembly in Caenorhabditis elegans. In order to address how B″ subunits interact with the PP2A core enzyme, we focused on a conditional allele, rsa-1(or598ts), and determined that this mutation specifically disrupts the protein interaction between RSA-1 and the PP2A structural subunit, PAA-1. Through genetic screening, we identified a putative interface on the PAA-1 structural subunit that interacts with a defined region of RSA-1/B″. In the context of previously published results, these data propose a mechanism of how different PP2A B-regulatory subunit families can bind the same holoenzyme in a mutually exclusive manner, to perform specific tasks in vivo.

Molecular Cloning and Characterization of the Human ErbB4 Gene: Identification of Novel Splice Isoforms in the Developing and Adult Brain

PubMed Central

Tan, Wei; Dean, Michael; Law, Amanda J.

2010-01-01

ErbB4 is a growth factor receptor tyrosine kinase essential for neurodevelopment. Genetic variation in ErbB4 is associated with schizophrenia and risk-associated polymorphisms predict overexpression of ErbB4 CYT-1 isoforms in the brain in the disorder. The molecular mechanism of association is unclear because the polymorphisms flank exon 3 of the gene and reside 700 kb distal to the CYT-1 defining exon. We hypothesized that the polymorphisms are indirectly associated with ErbB4 CYT-1 via splicing of exon 3 on the CYT-1 background. We report via cloning and sequencing of adult and fetal human brain cDNA libraries the identification of novel splice isoforms of ErbB4, whereby exon 3 is skipped (del.3). ErbB4 del.3 transcripts exist as CYT-2 isoforms and are predicted to produce truncated proteins. Furthermore, our data refine the structure of the human ErbB4 gene, clarify that juxtamembrane (JM) splice variants of ErbB4, JM-a and JM-b respectively, are characterized by the replacement of a 75 nucleotide (nt) sequence with a 45-nt insertion, and demonstrate that there are four alternative exons in the gene. Our analyses reveal that novel splice variants of ErbB4 exist in the developing and adult human brain and, given the failure to identify ErbB4 del.3 CYT-1 transcripts, suggest that the association of risk polymorphisms in the ErbB4 gene with CYT-1 transcript levels is not mediated via an exon 3 splicing event. PMID:20886074

Distribution of MICA alleles and haplotypes associated with HLA in the Korean population.

PubMed

Pyo, Chul-Woo; Hur, Seong-Suk; Kim, Yang-Kyum; Choi, Hee-Baeg; Kim, Tae-Yoon; Kim, Tai-Gyu

2003-03-01

The MICA (MHC class I chain-related gene A) is a polymorphic gene located 46 kb centromeric of the HLA-B gene, and is preferentially expressed in epithelial cells and intestinal mucosa. The MICA gene, similar to human leukocyte antigen (HLA) class I, displays a high degree of genetic polymorphism in exons 2, 3, 4, and 5, amounting to 54 alleles. In this study, we investigated the polymorphisms at exons coding for extracellular domains (exons 2, 3, and 4), and the GCT repeat polymorphism at the transmembrane (exon 5) of MICA in 199 unrelated healthy Koreans. Eight alleles were observed in the Korean population, with allele frequencies for MICA*010, MICA*00201, MICA*027, MICA*004, MICA*012, MICA*00801, MICA*00901, and MICA*00701 being 18.3%, 17.8%, 13.6%, 12.3%, 11.1%, 10.8%, 10.6%, and 3.3%, respectively. Strong linkage disequilibria were also observed between the MICA and HLA-B gene-MICA*00201-B58, MICA*004-B44, MICA*00701-B27, MICA*00801-B60, MICA*00901-B51, MICA*010-B62, MICA*012-B54, and MICA*027-B61. In the analysis of the haplotypes of HLA class I genes (HLA-A, B, and C) and the MICA, the most common haplotype was MICA*004-A33-B44-Cw*07, followed by MICA*00201-A2-B58-Cw*0302 and MICA*012-A2-B54-Cw*0102. The MICA null haplotype might be identified in the HLA-B48 homozygous individual. These results will provide an understanding of the role of MICA in transplantation, disease association, and population analyses in Koreans.

Deletion of the low-molecular-weight glutenin subunit allele Glu-A3a of wheat (Triticum aestivum L.) significantly reduces dough strength and breadmaking quality.

PubMed

Zhen, Shoumin; Han, Caixia; Ma, Chaoying; Gu, Aiqin; Zhang, Ming; Shen, Xixi; Li, Xiaohui; Yan, Yueming

2014-12-19

Low-molecular-weight glutenin subunits (LMW-GS), encoded by Glu-3 complex loci in hexaploid wheat, play important roles in the processing quality of wheat flour. To date, the molecular characteristics and effects on dough quality of individual Glu-3 alleles and their encoding proteins have been poorly studied. We used a Glu-A3 deletion line of the Chinese Spring (CS-n) wheat variety to conduct the first comprehensive study on the molecular characteristics and functional properties of the LMW-GS allele Glu-A3a. The Glu-A3a allele at the Glu-A3 locus in CS and its deletion in CS-n were identified and characterized by proteome and molecular marker methods. The deletion of Glu-A3a had no significant influence on plant morphological and yield traits, but significantly reduced the dough strength and breadmaking quality compared to CS. The complete sequence of the Glu-A3a allele was cloned and characterized, which was found to encode a B-subunit with longer repetitive domains and an increased number of α-helices. The Glu-A3a-encoded B-subunit showed a higher expression level and accumulation rate during grain development. These characteristics of the Glu-A3a allele could contribute to achieving superior gluten quality and demonstrate its potential application to wheat quality improvement. Furthermore, an allele-specific polymerase chain reaction (AS-PCR) marker for the Glu-A3a allele was developed and validated using different bread wheat cultivars, including near-isogenic lines (NILs) and recombinant inbred lines (RILs), which could be used as an effective molecular marker for gluten quality improvement through marker-assisted selection. This work demonstrated that the LMW-GS allele Glu-A3a encodes a specific LMW-i type B-subunit that significantly affects wheat dough strength and breadmaking quality. The Glu-A3a-encoded B-subunit has a long repetitive domain and more α-helix structures as well as a higher expression level and accumulation rate during grain development, which could facilitate the formation of wheat with a stronger dough structure and superior breadmaking quality.

Evidence for an unusual transmembrane configuration of AGG3, a class C Gγ subunit of Arabidopsis

DOE PAGES

Wolfenstetter, Susanne; Chakravorty, David; Kula, Ryan; ...

2014-12-22

Heterotrimeric G proteins are crucial for the perception of external signals and subsequent signal transduction in animal and plant cells. In both model systems, the complex is comprised of one Gα, one Gβ and one Gγ subunit. However, in addition to the canonical Gγ subunits (Class A), plants also possess two unusual, plant-specific classes of Gγ subunits (Classes B and C) not yet found in animals. These include Gγ subunits lacking the C-terminal CaaX motif (Class B) which is important for membrane anchoring of the protein, and thus give rise to a flexible subpopulation of Gβ/γ heterodimers that is notmore » necessarily restricted to the plasma membrane. Even more interesting, plants also contain Class C Gγ subunits which are twice the size of canonical Gγs, with a predicted transmembrane domain, and a large cysteine-rich, extracellular C-terminus. However, neither the presence of the transmembrane domain nor the membrane topology has been unequivocally demonstrated. Finally, we provide compelling evidence that AGG3, a Class C Ggamma subunit of Arabidopsis, contains a functional transmembrane domain, which is sufficient but not essential for plasma membrane localization, and that the cysteine-rich C-terminus is extracellular.« less

Crystallization and preliminary X-ray crystallographic analysis of the small subunit of the heterodimeric laccase POXA3b from Pleurotus ostreatus

PubMed Central

Ferraroni, Marta; Scozzafava, Andrea; Ullah, Sana; Tron, Thierry; Piscitelli, Alessandra; Sannia, Giovanni

2014-01-01

Laccases are multicopper oxidases of great biotechnological potential. While laccases are generally monomeric glycoproteins, the white-rot fungus Pleurotus ostreatus produces two closely related heterodimeric isoenzymes composed of a large subunit, homologous to the other fungal laccases, and a small subunit. The sequence of the small subunit does not show significant homology to any other protein or domain of known function and consequently its function is unknown. The highest similarity to proteins of known structure is to a putative enoyl-CoA hydratase/isomerase from Acinetobacter baumannii, which shows an identity of 27.8%. Diffraction-quality crystals of the small subunit of the heterodimeric laccase POXA3b (sPOXA3b) from P. ostreatus were obtained using the sitting-drop vapour-diffusion method at 294 K from a solution consisting of 1.8 M sodium formate, 0.1 M Tris–HCl pH 8.5. The crystals belonged to the tetragonal space group P41212 or P43212, with unit-cell parameters a = 126.6, c = 53.9 Å. The asymmetric unit contains two molecules related by a noncrystallographic twofold axis. A complete data set extending to a maximum resolution of 2.5 Å was collected at 100 K using a wavelength of 1.140 Å. PMID:24419623

Development of haplotype-specific molecular markers for the low-molecular-weight glutenin subunits

USDA-ARS?s Scientific Manuscript database

Low-molecular-weight glutenin subunits (LMW-GSs) are one of the major components of gluten and their allelic variation has been widely associated with numerous wheat end-use quality parameters. These proteins are encoded by multigene families located at the orthologous Glu-3 loci (Glu-A3, Glu-B3 and...

Polymorphisms at the 3' untranslated region of SLC11A1 gene are associated with protection to Brucella infection in goats.

PubMed

Iacoboni, Paola A; Hasenauer, Flavia C; Caffaro, M Eugenia; Gaido, Analia; Rossetto, Cristina; Neumann, Roberto D; Salatin, Antonio; Bertoni, Emiliano; Poli, Mario A; Rossetti, Carlos A

2014-08-15

Goats are susceptible to brucellosis and the detection of Brucella-infected animals is carried out by serological tests. In other ruminant species, polymorphisms in microsatellites (Ms) of 3' untranslated region (3'UTR) of the solute carrier family 11 member A1 (SLC11A1) gene were associated with resistance to Brucella abortus infection. Goats present two polymorphic Ms at the 3'UTR end of SLC11A1 gene, called regions A and B. Here, we evaluated if polymorphisms in regions A and/or B are associated with Brucella infection in goats. Serum (for the detection of Brucella-specific antibodies) and hair samples (for DNA isolation and structure analysis of the SLC11A1 gene) were randomly collected from 229 adult native goats from the northwest of Argentina. Serological status was evaluated by buffer plate antigen test (BPAT) complemented by the fluorescent polarization assay (FPA), and the genotype of the 3'UTR of the SLC11A1 gene was determined by capillary electrophoresis and confirmed by sequence analysis. Polymorphisms in regions A and B of the 3'UTR SLC11A1 gene were found statistically significant associated with protection to Brucella infection. Specifically, the association study indicates statistical significance of the allele A15 and B7/B7 genotype with absence of Brucella-specific antibodies (p=0.0003 and 0.0088, respectively). These data open a promising opportunity for limiting goat brucellosis through selective breeding of animals based on genetic markers associated with natural resistance to B. melitensis infection. Copyright © 2014 Elsevier B.V. All rights reserved.

D1/D2 domain of large-subunit ribosomal DNA for differentiation of Orpinomyces spp.

PubMed

Dagar, Sumit S; Kumar, Sanjay; Mudgil, Priti; Singh, Rameshwar; Puniya, Anil K

2011-09-01

This study presents the suitability of D1/D2 domain of large-subunit (LSU) ribosomal DNA (rDNA) for differentiation of Orpinomyces joyonii and Orpinomyces intercalaris based on PCR-restriction fragment length polymorphism (RFLP). A variation of G/T in O. intercalaris created an additional restriction site for AluI, which was used as an RFLP marker. The results demonstrate adequate heterogeneity in the LSU rDNA for species-level differentiation.

Effects of polymorphisms in beta1-adrenoceptor and alpha-subunit of G protein on heart rate and blood pressure during exercise test. The Finnish Cardiovascular Study.

PubMed

Nieminen, Tuomo; Lehtimäki, Terho; Laiho, Jarno; Rontu, Riikka; Niemelä, Kari; Kööbi, Tiit; Lehtinen, Rami; Viik, Jari; Turjanmaa, Väinö; Kähönen, Mika

2006-02-01

We tested whether the Arg389Gly and Ser49Gly polymorphisms of the beta1-adrenergic receptor gene ADRB1 and the T393C polymorphism of the G protein alpha-subunit gene GNAS1 modulate heart rate (HR) and blood pressure responses during an exercise stress test. The study population comprised 890 participants (563 men and 327 women, mean age 58.1 +/- 12.6 yr) of the Finnish Cardiovascular Study. Their HR, systolic (SAP), and diastolic arterial pressures (DAP) at rest, during exercise, and 4 min after the test were measured and analyzed by repeated-measurement ANOVA (RANOVA). Genotypes were detected by TaqMan 5' nuclease assay. In all subjects, and in men and women separately, the T393C of GNAS1 was the only polymorphism with genotype x time interaction in HR over the three study phases (P = 0.04, RANOVA). None of the polymorphisms presented genotype x time interaction in SAP or DAP responses (P > 0.10, RANOVA). In all subjects at rest, the Ser49Gly polymorphism of ADRB1 tended (P = 0.06, ANOVA) to differentiate HR. Arg389Gly polymorphism of ADRB1 affected maximal SAP during exercise (P = 0.04, ANOVA) and the change in SAP from rest to maximal (P = 0.03, ANOVA). Arg389 homozygotes, particularly men, were less likely to have ventricular extrasystoles during the exercise (odds ratio = 0.68, 95% confidence interval = 0.51-0.91, P = 0.009, and odds ratio = 0.60, 95% confidence interval = 0.42-0.86, P = 0.006, respectively) than did Gly389 carriers. In conclusion, polymorphisms examined appear to have modulatory effects on hemodynamics in a clinical exercise test setting. However, the effects in absolute numbers were minor and clinically possibly insignificant.

[Polymorphism analysis of MTHFR，BMPR1B and TYMS in microtia].

PubMed

Liu, N; Liu, Y F; Sui, J; Zhang, Y Q; Ma, S M; Wu, W J; Liang, G; Tan, Q

2017-03-20

Objective: To explore the relationship between MTHFR，BMPR1B and TYMS polymorphism and congenitial microtia in Chinese Han population. Method: A total of 180 microtia patients and 141 healthy participants were enrolled in this study.The genotyping of MTHFR rs4846049, BMPR1B rs1434536 and TYMS rs2790 of the participants were examined with multiple PCR. Frequencies and allele distribution of MTHFR rs4846049,BMPR1B rs1434536 and TYMS rs2790 between cases and control were analyzed with Chi-square test. Result: The genotype frequency distribution of TYMS rs27901 polymorphism was significantly different between two groups( P <0.05).Furthermore, gender stratified analysis showed that TYMS rs2790 polymorphism mainly increase the risks of congenitial microtia in male( P <0.05).Compared with AA genotype,the mircotia risks of subjects with AG GG AG+GG raised to 1.93, 3.23 and 2.10 times,respectively(95% CI :1.07-3.48、1.12-9.33 and 1.20-3.68).However,there was no relationship between MTHFR rs4846049, BMPR1B rs1434536 and microtia. Conclusion: The TYMS rs2790 polymorphism may be a risk factor of microtia in male. Copyright© by the Editorial Department of Journal of Clinical Otorhinolaryngology Head and Neck Surgery.

Mutation of neuron-specific chromatin remodeling subunit BAF53b: rescue of plasticity and memory by manipulating actin remodeling.

PubMed

Vogel Ciernia, Annie; Kramár, Enikö A; Matheos, Dina P; Havekes, Robbert; Hemstedt, Thekla J; Magnan, Christophe N; Sakata, Keith; Tran, Ashley; Azzawi, Soraya; Lopez, Alberto; Dang, Richard; Wang, Weisheng; Trieu, Brian; Tong, Joyce; Barrett, Ruth M; Post, Rebecca J; Baldi, Pierre; Abel, Ted; Lynch, Gary; Wood, Marcelo A

2017-05-01

Recent human exome-sequencing studies have implicated polymorphic Brg1-associated factor (BAF) complexes (mammalian SWI/SNF chromatin remodeling complexes) in several intellectual disabilities and cognitive disorders, including autism. However, it remains unclear how mutations in BAF complexes result in impaired cognitive function. Post-mitotic neurons express a neuron-specific assembly, nBAF, characterized by the neuron-specific subunit BAF53b. Subdomain 2 of BAF53b is essential for the differentiation of neuronal precursor cells into neurons. We generated transgenic mice lacking subdomain 2 of Baf53b (BAF53bΔSB2). Long-term synaptic potentiation (LTP) and long-term memory, both of which are associated with phosphorylation of the actin severing protein cofilin, were assessed in these animals. A phosphorylation mimic of cofilin was stereotaxically delivered into the hippocampus of BAF53bΔSB2 mice in an effort to rescue LTP and memory. BAF53bΔSB2 mutant mice show impairments in phosphorylation of synaptic cofilin, LTP, and memory. Both the synaptic plasticity and memory deficits are rescued by overexpression of a phosphorylation mimetic of cofilin. Baseline physiology and behavior were not affected by the mutation or the experimental treatment. This study suggests a potential link between nBAF function, actin cytoskeletal remodeling at the dendritic spine, and memory formation. This work shows that a targeted manipulation of synaptic function can rescue adult plasticity and memory deficits caused by manipulations of nBAF, and thereby provides potential novel avenues for therapeutic development for multiple intellectual disability disorders. © 2017 Vogel Ciernia et al.; Published by Cold Spring Harbor Laboratory Press.

Deciphering the function of the CNGB1b subunit in olfactory CNG channels.

PubMed

Nache, Vasilica; Wongsamitkul, Nisa; Kusch, Jana; Zimmer, Thomas; Schwede, Frank; Benndorf, Klaus

2016-07-11

Olfactory cyclic nucleotide-gated (CNG) ion channels are key players in the signal transduction cascade of olfactory sensory neurons. The second messengers cAMP and cGMP directly activate these channels, generating a depolarizing receptor potential. Olfactory CNG channels are composed of two CNGA2 subunits and two modulatory subunits, CNGA4, and CNGB1b. So far the exact role of the modulatory subunits for channel activation is not fully understood. By measuring ligand binding and channel activation simultaneously, we show that in functional heterotetrameric channels not only the CNGA2 subunits and the CNGA4 subunit but also the CNGB1b subunit binds cyclic nucleotides and, moreover, also alone translates this signal to open the pore. In addition, we show that the CNGB1b subunit is the most sensitive subunit in a heterotetrameric channel to cyclic nucleotides and that it accelerates deactivation to a similar extent as does the CNGA4 subunit. In conclusion, the CNGB1b subunit participates in ligand-gated activation of olfactory CNG channels and, particularly, contributes to rapid termination of odorant signal in an olfactory sensory neuron.

Mutations in the PP2A regulatory subunit B family genes PPP2R5B, PPP2R5C and PPP2R5D cause human overgrowth.

PubMed

Loveday, Chey; Tatton-Brown, Katrina; Clarke, Matthew; Westwood, Isaac; Renwick, Anthony; Ramsay, Emma; Nemeth, Andrea; Campbell, Jennifer; Joss, Shelagh; Gardner, McKinlay; Zachariou, Anna; Elliott, Anna; Ruark, Elise; van Montfort, Rob; Rahman, Nazneen

2015-09-01

Overgrowth syndromes comprise a group of heterogeneous disorders characterised by excessive growth parameters, often in association with intellectual disability. To identify new causes of human overgrowth, we have been undertaking trio-based exome sequencing studies in overgrowth patients and their unaffected parents. Prioritisation of functionally relevant genes with multiple unique de novo mutations revealed four mutations in protein phosphatase 2A (PP2A) regulatory subunit B family genes protein phosphatase 2, regulatory Subunit B', beta (PPP2R5B); protein phosphatase 2, regulatory Subunit B', gamma (PPP2R5C); and protein phosphatase 2, regulatory Subunit B', delta (PPP2R5D). This observation in 3 related genes in 111 individuals with a similar phenotype is greatly in excess of the expected number, as determined from gene-specific de novo mutation rates (P = 1.43 × 10(-10)). Analysis of exome-sequencing data from a follow-up series of overgrowth probands identified a further pathogenic mutation, bringing the total number of affected individuals to 5. Heterozygotes shared similar phenotypic features including increased height, increased head circumference and intellectual disability. The mutations clustered within a region of nine amino acid residues in the aligned protein sequences (P = 1.6 × 10(-5)). We mapped the mutations onto the crystal structure of the PP2A holoenzyme complex to predict their molecular and functional consequences. These studies suggest that the mutations may affect substrate binding, thus perturbing the ability of PP2A to dephosphorylate particular protein substrates. PP2A is a major negative regulator of v-akt murine thymoma viral oncogene homolog 1 (AKT). Thus, our data further expand the list of genes encoding components of the phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/AKT signalling cascade that are disrupted in human overgrowth conditions. © The Author 2015. Published by Oxford University Press.

Cell cycle-dependent regulation of Greatwall kinase by protein phosphatase 1 and regulatory subunit 3B.

PubMed

Ren, Dapeng; Fisher, Laura A; Zhao, Jing; Wang, Ling; Williams, Byron C; Goldberg, Michael L; Peng, Aimin

2017-06-16

Greatwall (Gwl) kinase plays an essential role in the regulation of mitotic entry and progression. Mitotic activation of Gwl requires both cyclin-dependent kinase 1 (CDK1)-dependent phosphorylation and its autophosphorylation at an evolutionarily conserved serine residue near the carboxyl terminus (Ser-883 in Xenopus ). In this study we show that Gwl associates with protein phosphatase 1 (PP1), particularly PP1γ, which mediates the dephosphorylation of Gwl Ser-883. Consistent with the mitotic activation of Gwl, its association with PP1 is disrupted in mitotic cells and egg extracts. During mitotic exit, PP1-dependent dephosphorylation of Gwl Ser-883 occurs prior to dephosphorylation of other mitotic substrates; replacing endogenous Gwl with a phosphomimetic S883E mutant blocks mitotic exit. Moreover, we identified PP1 regulatory subunit 3B (PPP1R3B) as a targeting subunit that can direct PP1 activity toward Gwl. PPP1R3B bridges PP1 and Gwl association and promotes Gwl Ser-883 dephosphorylation. Consistent with the cell cycle-dependent association of Gwl and PP1, Gwl and PPP1R3B dissociate in M phase. Interestingly, up-regulation of PPP1R3B facilitates mitotic exit and blocks mitotic entry. Thus, our study suggests PPP1R3B as a new cell cycle regulator that functions by governing Gwl dephosphorylation. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Mediator Complex Subunits MED2, MED5, MED16, and MED23 Genetically Interact in the Regulation of Phenylpropanoid Biosynthesis.

PubMed

Dolan, Whitney L; Dilkes, Brian P; Stout, Jake M; Bonawitz, Nicholas D; Chapple, Clint

2017-12-01

The phenylpropanoid pathway is a major global carbon sink and is important for plant fitness and the engineering of bioenergy feedstocks. In Arabidopsis thaliana , disruption of two subunits of the transcriptional regulatory Mediator complex, MED5a and MED5b, results in an increase in phenylpropanoid accumulation. By contrast, the semidominant MED5b mutation reduced epidermal fluorescence4-3 ( ref4-3 ) results in dwarfism and constitutively repressed phenylpropanoid accumulation. Here, we report the results of a forward genetic screen for suppressors of ref4-3. We identified 13 independent lines that restore growth and/or phenylpropanoid accumulation in the ref4-3 background. Two of the suppressors restore growth without restoring soluble phenylpropanoid accumulation, indicating that the growth and metabolic phenotypes of the ref4-3 mutant can be genetically disentangled. Whole-genome sequencing revealed that all but one of the suppressors carry mutations in MED5b or other Mediator subunits. RNA-seq analysis showed that the ref4-3 mutation causes widespread changes in gene expression, including the upregulation of negative regulators of the phenylpropanoid pathway, and that the suppressors reverse many of these changes. Together, our data highlight the interdependence of individual Mediator subunits and provide greater insight into the transcriptional regulation of phenylpropanoid biosynthesis by the Mediator complex. © 2017 American Society of Plant Biologists. All rights reserved.

Neutralizing activity and protective immunity to ricin toxin conferred by B subunit (RTB)-specific Fab fragments.

PubMed

Yermakova, Anastasiya; Mantis, Nicholas J

2013-09-01

SylH3 and 24B11 are murine monoclonal antibodies directed against different epitopes on ricin toxin's binding (RTB) subunit that have been shown to passively protect mice against ricin challenge. Here we report that Fab fragments of SylH3 and 24B11 neutralize ricin in a cell based assay, and in a mouse challenge model as effectively as their respective full length parental IgGs. These data demonstrate that immunity to ricin can occur independent of Fc-mediated clearance. Copyright © 2013 Elsevier Ltd. All rights reserved.

Identification of single nucleotide polymorphism in protein phosphatase 1 regulatory subunit 11 gene in Murrah bulls

PubMed Central

Jain, Varsha; Patel, Brijesh; Umar, Farhat Paul; Ajithakumar, H. M.; Gurjar, Suraj K.; Gupta, I. D.; Verma, Archana

2017-01-01

Aim: This study was conducted with the objective to identify single nucleotide polymorphism (SNP) in protein phosphatase 1 regulatory subunit 11 (PPP1R11) gene in Murrah bulls. Materials and Methods: Genomic DNA was isolated by phenol–chloroform extraction method from the frozen semen samples of 65 Murrah bulls maintained at Artificial Breeding Research Centre, ICAR-National Dairy Research Institute, Karnal. The quality and concentration of DNA was checked by spectrophotometer reading and agarose gel electrophoresis. The target region of PPP1R11 gene was amplified using four sets of primer designed based on Bos taurus reference sequence. The amplified products were sequenced and aligned using Clustal Omega for identification of SNPs. Animals were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) using EcoNI restriction enzyme. Results: The sequences in the NCBI accession number NW_005785016.1 for Bubalus bubalis were compared and aligned with the edited sequences of Murrah bulls with Clustal Omega software. A total of 10 SNPs were found, out of which 1 at 5’UTR, 3 at intron 1, and 6 at intron 2 region. PCR-RFLP using restriction enzyme EcoNI revealed only AA genotype indicating monomorphism in PPP1R11 gene of all Murrah animals included in the study. Conclusion: A total of 10 SNPs were found. PCR-RFLP revealed only AA genotype indicating monomorphism in PPP1R11 gene of all Murrah animals included in the study, due to which association analysis with conception rate was not feasible. PMID:28344410

Homologous kappa-neurotoxins exhibit residue-specific interactions with the alpha 3 subunit of the nicotinic acetylcholine receptor: a comparison of the structural requirements for kappa-bungarotoxin and kappa-flavitoxin binding.

PubMed

McLane, K E; Weaver, W R; Lei, S; Chiappinelli, V A; Conti-Tronconi, B M

1993-07-13

kappa-Flavotoxin (kappa-FTX), a snake neurotoxin that is a selective antagonist of certain neuronal nicotinic acetylcholine receptors (AChRs), has recently been isolated and characterized [Grant, G. A., Frazier, M. W., & Chiappinelli, V. A. (1988) Biochemistry 27, 1532-1537]. Like the related snake toxin kappa-bungarotoxin (kappa-BTX), kappa-FTX binds with high affinity to alpha 3 subtypes of neuronal AChRs, even though there are distinct sequence differences between the two toxins. To further characterize the sequence regions of the neuronal AChR alpha 3 subunit involved in formation of the binding site for this family of kappa-neurotoxins, we investigated kappa-FTX binding to overlapping synthetic peptides screening the alpha 3 subunit sequence. A sequence region forming a "prototope" for kappa-FTX was identified within residues alpha 3 (51-70), confirming the suggestions of previous studies on the binding of kappa-BTX to the alpha 3 subunit [McLane, K. E., Tang, F., & Conti-Tronconi, B. M. (1990) J. Biol. Chem. 265, 1537-1544] and alpha-bungarotoxin to the Torpedo AChR alpha subunit [Conti-Tronconi, B. M., Tang, F., Diethelm, B. M., Spencer, S. R., Reinhardt-Maelicke, S., & Maelicke, A. (1990) Biochemistry 29, 6221-6230] that this sequence region is involved in formation of a cholinergic site. Single residue substituted analogues, where each residue of the sequence alpha 3 (51-70) was sequentially replaced by a glycine, were used to identify the amino acid side chains involved in the interaction of this prototope with kappa-FTX.(ABSTRACT TRUNCATED AT 250 WORDS)

Molecular Basis of Differential B-Pentamer Stability of Shiga Toxins 1 and 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Conrady, Deborah G.; Flagler, Michael J.; Friedmann, David R.

2012-06-27

Escherichia coli strain O157:H7 is a major cause of food poisoning that can result in severe diarrhea and, in some cases, renal failure. The pathogenesis of E. coli O157:H7 is in large part due to the production of Shiga toxin (Stx), an AB{sub 5} toxin that consists of a ribosomal RNA-cleaving A-subunit surrounded by a pentamer of receptor-binding B subunits. There are two major isoforms, Stx1 and Stx2, which differ dramatically in potency despite having 57% sequence identity. Animal studies and epidemiological studies show Stx2 is associated with more severe disease. Although the molecular basis of this difference is unknown,more » data suggest it is associated with the B-subunit. Mass spectrometry studies have suggested differential B-pentamer stability between Stx1 and Stx2. We have examined the relative stability of the B-pentamers in solution. Analytical ultracentrifugation using purified B-subunits demonstrates that Stx2B, the more deadly isoform, shows decreased pentamer stability compared to Stx1B (EC{sub 50} = 2.3 {micro}M vs. EC{sub 50} = 0.043 {micro}M for Stx1B). X-ray crystal structures of Stx1B and Stx2B identified a glutamine in Stx2 (versus leucine in Stx1) within the otherwise strongly hydrophobic interface between B-subunits. Interchanging these residues switches the stability phenotype of the B-pentamers of Stx1 and Stx2, as demonstrated by analytical ultracentrifugation and circular dichroism. These studies demonstrate a profound difference in stability of the B-pentamers in Stx1 and Stx2, illustrate the mechanistic basis for this differential stability, and provide novel reagents to test the basis for differential pathogenicity of these toxins.« less

The role of TcdB and TccC subunits in secretion of the Photorhabdus Tcd toxin complex.

PubMed

Yang, Guowei; Waterfield, Nicholas R

2013-01-01

The Toxin Complex (TC) is a large multi-subunit toxin encoded by a range of bacterial pathogens. The best-characterized examples are from the insect pathogens Photorhabdus, Xenorhabdus and Yersinia. They consist of three large protein subunits, designated A, B and C that assemble in a 5∶1∶1 stoichiometry. Oral toxicity to a range of insects means that some have the potential to be developed as pest control technology. The three subunit proteins do not encode any recognisable export sequences and as such little progress has been made in understanding their secretion. We have developed heterologous TC production and secretion models in E. coli and used them to ascribe functions to different domains of the crucial B+C sub-complex. We have determined that the B and C subunits use a secretion mechanism that is either encoded by the proteins themselves or employ an as yet undefined system common to laboratory strains of E. coli. We demonstrate that both the N-terminal domains of the B and C subunits are required for secretion of the whole complex. We propose a model whereby the N-terminus of the C-subunit toxin exports the B+C sub-complex across the inner membrane while that of the B-subunit allows passage across the outer membrane. We also demonstrate that even in the absence of the B-subunit, that the C-subunit can also facilitate secretion of the larger A-subunit. The recognition of this novel export system is likely to be of importance to future protein secretion studies. Finally, the identification of homologues of B and C subunits in diverse bacterial pathogens, including Burkholderia and Pseudomonas, suggests that these toxins are likely to be important in a range of different hosts, including man.

Selective Proteasomal Degradation of the B′β Subunit of Protein Phosphatase 2A by the E3 Ubiquitin Ligase Adaptor Kelch-like 15*

PubMed Central

Oberg, Elizabeth A.; Nifoussi, Shanna K.; Gingras, Anne-Claude; Strack, Stefan

2012-01-01

Protein phosphatase 2A (PP2A), a ubiquitous and pleiotropic regulator of intracellular signaling, is composed of a core dimer (AC) bound to a variable (B) regulatory subunit. PP2A is an enzyme family of dozens of heterotrimers with different subcellular locations and cellular substrates dictated by the B subunit. B′β is a brain-specific PP2A regulatory subunit that mediates dephosphorylation of Ca2+/calmodulin-dependent protein kinase II and tyrosine hydroxylase. Unbiased proteomic screens for B′β interactors identified Cullin3 (Cul3), a scaffolding component of E3 ubiquitin ligase complexes, and the previously uncharacterized Kelch-like 15 (KLHL15). KLHL15 is one of ∼40 Kelch-like proteins, many of which have been identified as adaptors for the recruitment of substrates to Cul3-based E3 ubiquitin ligases. Here, we report that KLHL15-Cul3 specifically targets B′β to promote turnover of the PP2A subunit by ubiquitylation and proteasomal degradation. Comparison of KLHL15 and B′β tissue expression profiles suggests that the E3 ligase adaptor contributes to selective expression of the PP2A/B′β holoenzyme in the brain. We mapped KLHL15 residues critical for homodimerization as well as interaction with Cul3 and B′β. Explaining PP2A subunit selectivity, the divergent N terminus of B′β was found necessary and sufficient for KLHL15-mediated degradation, with Tyr-52 having an obligatory role. Although KLHL15 can interact with the PP2A/B′β heterotrimer, it only degrades B′β, thus promoting exchange with other regulatory subunits. E3 ligase adaptor-mediated control of PP2A holoenzyme composition thereby adds another layer of regulation to cellular dephosphorylation events. PMID:23135275

[Relation of MBL ExonI 54 and NFκB1-94ins/del ATTG Polymorphism with Fever during Neutropenia in Patients with Acute Leukaemia after Chemotherapy].

PubMed

Xu, Wen-Ning; Jiang, Zu-Jun; Li, Yong-Hua; Xiao, Hao-Wen; Gao, Yang; Pang, Yan; Ouyang, Lin; Liu, Zeng-Hui; Zhang, Le-Qing; Wang, Yang; Xiao, Yang

2015-10-01

To explore the correlation between MBL ExonI 54 and NFκB1-94ins/del ATTG polymorphism and fever during neutropenia in patients with acute leukaemia (AL) (except M3) after first chemotherapy in Chinese Han population. Blood samples obtained from 76 fever patients with AL during neutropenia episodes were detected to analyse single nucleotide polymorphism (SNP) in the MBL ExonI 54 and NFκB1-94ins/del ATTG gene, and analyse the correlation between above-mentioned 2 polymorphisms and fever during neutropenia of AL patients after chemotherapy. In 76 patients, no correlation were found between MBL ExonI 54 and NFκB1-94ins/del ATTG polymorphism and fever during neutropenia in patients with acute leukaemia after chemotherapy (P > 0.05). No significant relation were found in sex, age, underlying disease, disease status or degrees of neutropenia in febrile neutropenia between MBL ExonI 54 and NFκB1-94ins/del ATTG polymorphism (P > 0.05). However, patients with MBL ExonI 54 mutation presented longer febrile duration with a median of 5 days compared to 3 days of patients with wildtype MBL ExonI 54 genotype (P < 0.05). There is no clear correlation between MBL ExonI 54 and NFκB1-94ins/del ATTG polymorphism and fever during neutropenia in patients with acute leukaemia after chemotherapy. However, the patients with MBL ExonI 54 mutation have been observed to present a longer febrile duration.

Interaction between cholesteryl ester transfer protein and hepatic lipase encoding genes and the risk of type 2 diabetes: results from the Telde study.

PubMed

López-Ríos, Laura; Nóvoa, Francisco J; Chirino, Ricardo; Varillas, Francisco; Boronat-Cortés, Mauro; Wägner, Ana M

2011-01-01

Diabetic dyslipidaemia is common in type 2 diabetes (T2D) and insulin resistance and often precedes the onset of T2D. The Taq1B polymorphism in CETP (B1 and B2 alleles) (rs708272) and the G-250A polymorphism in LIPC (rs2070895) are associated with changes in enzyme activity and lipid concentrations. Our aim was to assess the effects of both polymorphisms on the risk of T2D. In a case-control study from the population-based Telde cohort, both polymorphisms were analysed by PCR-based methods. Subjects were classified, according to an oral glucose tolerance test, into diabetic (N = 115) and pre-diabetic (N = 116); 226 subjects with normal glucose tolerance, matched for age and gender, were included as controls. Chi-square (comparison between groups) and logistic regression (identification of independent effects) were used for analysis. The B1B1 Taq1B CETP genotype frequency increased with worsening glucose metabolism (42.5%, 46.1% and 54.3% in control, IGR and diabetic group; p = 0.042). This polymorphism was independently associated with an increased risk of diabetes (OR: 1.828; IC 95%: 1.12-2.99; p = 0.016), even after adjusting by confounding variables, whereas the LIPC polymorphism was not. Regarding the interaction between both polymorphisms, in the B1B1 genotype carriers, the absence of the minor (A) allele of the LIPC polymorphism increased the risk of having diabetes. The presence of the B1B1 Taq1B CETP genotype contributes to the presence of diabetes, independently of age, sex, BMI and waist. However, among carriers of B1B1, the presence of GG genotype of the -250 LIPC polymorphism increases this risk further.

Molecular phylogenetic diversity, multilocus haplotype nomenclature, and in vitro antifungal resistance within the Fusarium solani species complex.

PubMed

O'Donnell, Kerry; Sutton, Deanna A; Fothergill, Annette; McCarthy, Dora; Rinaldi, Michael G; Brandt, Mary E; Zhang, Ning; Geiser, David M

2008-08-01

Members of the species-rich Fusarium solani species complex (FSSC) are responsible for approximately two-thirds all fusarioses of humans and other animals. In addition, many economically important phytopathogenic species are nested within this complex. Due to their increasing clinical relevance and because most of the human pathogenic and plant pathogenic FSSC lack Latin binomials, we have extended the multilocus haplotype nomenclatural system introduced in a previous study (D. C. Chang, G. B. Grant, K. O'Donnell, K. A. Wannemuehler, J. Noble-Wang, C. Y. Rao, L. M. Jacobson, C. S. Crowell, R. S. Sneed, F. M. T. Lewis, J. K. Schaffzin, M. A. Kainer, C. A. Genese, E. C. Alfonso, D. B. Jones, A. Srinivasan, S. K. Fridkin, and B. J. Park, JAMA 296:953-963, 2006) to all 34 species within the medically important FSSC clade 3 to facilitate global epidemiological studies. The typing scheme is based on polymorphisms in portions of the following three genes: the internal transcribed spacer region and domains D1 plus D2 of the nuclear large-subunit rRNA, the translation elongation factor 1 alpha gene (EF-1alpha), and the second largest subunit of RNA polymerase II gene (RPB2). Of the 251 isolates subjected to multilocus DNA sequence typing, 191 sequence types were differentiated, and these were distributed among three strongly supported clades designated 1, 2, and 3. All of the mycosis-associated isolates were restricted to FSSC clade 3, as previously reported (N. Zhang, K. O'Donnell, D. A. Sutton, F. A Nalim, R. C. Summerbell, A. A. Padhye, and D. M. Geiser, J. Clin. Microbiol. 44:2186-2190, 2006), and these represent at least 20 phylogenetically distinct species. Analyses of the combined DNA sequence data by use of two separate phylogenetic methods yielded the most robust hypothesis of evolutionary relationships and genetic diversity within the FSSC to date. The in vitro activities of 10 antifungals tested against 19 isolates representing 18 species that span the breadth of the FSSC phylogeny show that members of this complex are broadly resistant to these drugs.

Comparison of the genetic variability of Blastocystis subtypes between human carriers from two contrasting climatic regions of México.

PubMed

Villegas-Gómez, Isaac; Martínez-Hernández, Fernando; Urrea-Quezada, Alejandro; González-Díaz, Mariana; Durazo, María; Hernández, Jesús; Orozco-Mosqueda, Guadalupe Erendira; Villalobos, Guiehdani; Maravilla, Pablo; Valenzuela, Olivia

2016-10-01

Blastocystis sp. is an anaerobic intestinal microorganism commonly identified in the feces of several animals, including humans. Blastocystis exhibits high genetic polymorphism and at least 17 subtypes (ST) have been identified; ST1-ST3 are frequently found in the Americas. Furthermore, in vitro assays have shown that temperature and humidity can affect the viability of Blastocystis cysts. In this study, we describe the genetic variability and genetic differentiation among and within Blastocystis STs in adults and children from the cities of Hermosillo and Morelia cities, which represent arid and humid subtropical climatic regions of México, respectively. Phylogenetic and genetic diversity was assessed by analyzing a region of the small subunit ribosomal DNA (SSU rDNA) gene as a marker. Blastocystis ST3 and ST1 were associated with children from Hermosillo and Morelia, respectively. An analysis of the nucleotide diversity (π) and haplotype polymorphism (θ) indexes showed that they were similar within each ST, but different between ST1 and ST3. Interestingly, the group of symptomatic carriers from Hermosillo showed scarce mean nucleotide diversity compared to the asymptomatic carriers (0.0039±0.0030 and 0.0329±0.0286, respectively). Furthermore, the gene flow and genetic differentiation indexes between the children and adults suggested that the Blastocystis haplotypes in the adult carriers were "highly mobile" among humans, while the haplotypes found in the children were more isolated and genetically differentiated between them. Copyright © 2016 Elsevier B.V. All rights reserved.

SETDB1 HISTONE METHYLTRANSFERASE REGULATES MOOD-RELATED BEHAVIORS AND EXPRESSION OF THE NMDA RECEPTOR SUBUNIT NR2B

PubMed Central

Jiang, Yan; Jakovcevski, Mira; Bharadwaj, Rahul; Connor, Caroline; Schroeder, Frederick A.; Lin, Cong L.; Straubhaar, Juerg; Martin, Gilles; Akbarian, Schahram

2010-01-01

Histone methyltransferases specific for the histone H3-lysine 9 (H3K9) residue, including Setdb1 (Set domain, bifurcated 1)/Eset/Kmt1e are associated with repressive chromatin remodeling and expressed in adult brain, but potential effects on neuronal function and behavior remain unexplored. Here, we report that transgenic mice with increased Setdb1 expression in adult forebrain neurons show antidepressant-like phenotypes in behavioral paradigms for anhedonia, despair and learned helplessness. Chromatin immunoprecipitation in conjunction with DNA tiling arrays (ChIP-chip) revealed that genomic occupancies of neuronal Setdb1 are limited to less than 1% of annotated genes, which include the NMDA receptor subunit NR2B/Grin2B and other ionotropic glutamate receptor genes. Chromatin conformation capture (“3C”) and Setdb1-ChIP revealed a loop formation tethering the NR2B/Grin2b promoter to the Setdb1 target site positioned 30Kb downstream of the transcription start site. In hippocampus and ventral striatum, two key structures in the neuronal circuitry regulating mood-related behaviors, Setdb1-mediated repressive histone methylation at NR2B/Grin2b was associated with decreased NR2B expression and EPSP insensitivity to pharmacological blockade of NR2B, and accelerated NMDA receptor desensitization consistent with a shift in NR2A/B subunit ratios. In wildtype mice, systemic treatment with the NR2B antagonist, Ro-256981, and hippocampal siRNA-mediated NR2B/Grin2b knockdown, resulted in behavioral changes similar to those elicited by the Setdb1 transgene. Together, these findings point to a role for neuronal Setdb1 in the regulation of affective and motivational behaviors through repressive chromatin remodeling at a select set of target genes, resulting in altered NMDA receptor subunit composition and other molecular adaptations. PMID:20505083

D1/D2 Domain of Large-Subunit Ribosomal DNA for Differentiation of Orpinomyces spp.▿

PubMed Central

Dagar, Sumit S.; Kumar, Sanjay; Mudgil, Priti; Singh, Rameshwar; Puniya, Anil K.

2011-01-01

This study presents the suitability of D1/D2 domain of large-subunit (LSU) ribosomal DNA (rDNA) for differentiation of Orpinomyces joyonii and Orpinomyces intercalaris based on PCR-restriction fragment length polymorphism (RFLP). A variation of G/T in O. intercalaris created an additional restriction site for AluI, which was used as an RFLP marker. The results demonstrate adequate heterogeneity in the LSU rDNA for species-level differentiation. PMID:21784906

Change of subunit composition of mitochondrial complex II (succinate-ubiquinone reductase/quinol-fumarate reductase) in Ascaris suum during the migration in the experimental host.

PubMed

Iwata, Fumiko; Shinjyo, Noriko; Amino, Hisako; Sakamoto, Kimitoshi; Islam, M Khyrul; Tsuji, Naotoshi; Kita, Kiyoshi

2008-03-01

The mitochondrial metabolic pathway of the parasitic nematode Ascaris suum changes dramatically during its life cycle, to adapt to changes in the environmental oxygen concentration. We previously showed that A. suum mitochondria express stage-specific isoforms of complex II (succinate-ubiquinone reductase: SQR/quinol-fumarate reductase: QFR). The flavoprotein (Fp) and small subunit of cytochrome b (CybS) in adult complex II differ from those of infective third stage larval (L3) complex II. However, there is no difference in the iron-sulfur cluster (Ip) or the large subunit of cytochrome b (CybL) between adult and L3 isoforms of complex II. In the present study, to clarify the changes that occur in the respiratory chain of A. suum larvae during their migration in the host, we examined enzymatic activity, quinone content and complex II subunit composition in mitochondria of lung stage L3 (LL3) A. suum larvae. LL3 mitochondria showed higher QFR activity ( approximately 160 nmol/min/mg) than mitochondria of A. suum at other stages (L3: approximately 80 nmol/min/mg; adult: approximately 70 nmol/min/mg). Ubiquinone content in LL3 mitochondria was more abundant than rhodoquinone ( approximately 1.8 nmol/mg versus approximately 0.9 nmol/mg). Interestingly, the results of two-dimensional bule-native/sodium dodecyl sulfate polyacrylamide gel electrophoresis analyses showed that LL3 mitochondria contained larval Fp (Fp(L)) and adult Fp (Fp(A)) at a ratio of 1:0.56, and that most LL3 CybS subunits were of the adult form (CybS(A)). This clearly indicates that the rearrangement of complex II begins with a change in the isoform of the anchor CybS subunit, followed by a similar change in the Fp subunit.

Comparison of macro and micro Raman measurement for reliable quantitative analysis of pharmaceutical polymorphs.

PubMed

Paiva, Eduardo M; da Silva, Vitor H; Poppi, Ronei J; Pereira, Claudete F; Rohwedder, Jarbas J R

2018-05-12

This work reports on the use of micro- and macro-Raman measurements for quantification of mebendazole (MBZ) polymorphs A, B, and C in mixtures. Three Raman spectrophotometers were studied with a laser spot size of 3, 80 and 100 μm and spectral resolutions of 3.9, 9 and 4 cm -1 , respectively. The samples studied were ternary mixtures varying the MBZ polymorphs A and C from 0 to 100% and polymorph B from 0 to 30%. Partial Least Squares (PLS) regression models were developed using the pre-processing spectra (2nd derivative) of the ternary mixtures. The best performance was obtained when the macro-Raman configuration was applied, obtaining RMSEP values of 1.68%, 1.24% and 2.03% w/w for polymorphs A, B, and C, respectively. In general, micro-Raman presented worst results for MBZ polymorphs prediction because the spectra obtained with this configuration does not represent the bulk proportion of mixtures, which have different particle morphologies and sizes. In addition, the influence of these particle features on micro-Raman measurements was also studied. Finally, the results demonstrated that reliable analytical quantifying of MBZ polymorphs can be reached using a laser with wider area illuminated, thus enabling acquisition of more reproductive and representative spectra of the mixtures. Copyright © 2018 Elsevier B.V. All rights reserved.

Dual-color quantum dot detection of a heterotetrameric potassium channel (hKCa3.1).

PubMed

Waschk, Daniel E J; Fabian, Anke; Budde, Thomas; Schwab, Albrecht

2011-04-01

Potassium channels play a key role in establishing the cell membrane potential and are expressed ubiquitously. Today, more than 70 mammalian K(+) channel genes are known. The diversity of K(+) channels is further increased by the fact that different K(+) channel family members may assemble to form heterotetramers. We present a method based on fluorescence microscopy to determine the subunit composition of a tetrameric K(+) channel. We generated artificial "heteromers" of the K(+) channel hK(Ca)3.1 by coexpressing two differently tagged hK(Ca)3.1 constructs containing either an extracellular hemagglutinin (HA) or an intracellular V5 epitope. hK(Ca)3.1 channel subunits were detected in the plasma membrane of MDCK-F cells or HEK293 cells by labeling the extra- and intracellular epitopes with differently colored quantum dots (QDs). As previously shown for the extracellular part of hK(Ca)3.1 channels, its intracellular domain can also bind only one QD label at a time. When both channel subunits were coexpressed, 27.5 ± 1.8% and 24.9 ± 2.1% were homotetramers consisting of HA- and V5-tagged subunits, respectively. 47.6 ± 3.2% of the channels were heteromeric and composed of both subunits. The frequency distribution of HA- and V5-tagged homo- and heteromeric hK(Ca)3.1 channels is reminiscent of the binomial distribution (a + b)(2) = a(2) + 2ab + b(2). Along these lines, our findings are consistent with the notion that hK(Ca)3.1 channels are assembled from two homomeric dimers and not randomly from four independent subunits. We anticipate that our technique will be applicable to other heteromeric membrane proteins, too.

Polymorphism of follicle stimulating hormone beta (FSHβ) subunit gene and its association with litter traits in giant panda.

PubMed

Huang, Xiaoyu; Li, Desheng; Wang, Jiwen; Huang, Yan; Han, Chunchun; Zhang, Guiquan; Huang, Zhi; Wu, Honglin; Wei, Ming; Wang, Guosong; Hu, Haiping; Deng, Tao; He, Tao; Zhou, Yingming; Song, Shixian; Luo, Bo; Zhang, Heming

2013-11-01

The different SSCP patterns of the follicle stimulating hormone beta (FSHβ) gene amplified by three pairs of primers were sequenced. Comparisons among the three nucleotide sequences of three genotypes indicated that three base substitutions (A213T, A91G, and A89C) were detected in FSHβ gene, which A213T substitution led to one amino acids mutation (Lys > Met), and the other two substitutions were synonymous mutations. The AA, AB and BB genotypes patterns obtained by FSHβ primer1 had evident relation with the litter traits, but the SSCP genotypes patterns obtained by FSHβ primer2 and primer3 had no evident relation with the litter traits in giant panda. The giant panda with AA and AB genotype had the largest litter size and multiparity rate compared with the BB genotypes (P < 0.05). We speculated that the giant pandas with the A allele have better litter traits than those with the B allele.

On the Mg(2+) binding site of the ε subunit from bacterial F-type ATP synthases.

PubMed

Krah, Alexander; Takada, Shoji

2015-10-01

F-type ATP synthases, central energy conversion machines of the cell synthesize adenosine triphosphate (ATP) using an electrochemical gradient across the membrane and, reversely, can also hydrolyze ATP to pump ions across the membrane, depending on cellular conditions such as ATP concentration. To prevent wasteful ATP hydrolysis, mammalian and bacterial ATP synthases possess different regulatory mechanisms. In bacteria, a low ATP concentration induces a conformational change in the ε subunit from the down- to up-states, which inhibits ATP hydrolysis. Moreover, the conformational change of the ε subunit depends on Mg(2+) concentration in some bacteria such as Bacillus subtilis, but not in others. This diversity makes the ε subunit a potential target for antibiotics. Here, performing molecular dynamics simulations, we identify the Mg(2+) binding site in the ε subunit from B. subtilis as E59 and E86. The free energy analysis shows that the first-sphere bi-dentate coordination of the Mg(2+) ion by the two glutamates is the most stable state. In comparison, we also clarify the reason for the absence of Mg(2+) dependency in the ε subunit from thermophilic Bacillus PS3, despite the high homology to that from B. subtilis. Sequence alignment suggests that this Mg(2+) binding motif is present in the ε subunits of some pathogenic bacteria. In addition we discuss strategies to stabilize an isolated ε subunit carrying the Mg(2+) binding motif by site directed mutagenesis, which also can be used to crystallize Mg(2+) dependent ε subunits in future. Copyright © 2015 Elsevier B.V. All rights reserved.

Short-term sleep deprivation impairs spatial working memory and modulates expression levels of ionotropic glutamate receptor subunits in hippocampus.

PubMed

Xie, Meilan; Yan, Jie; He, Chao; Yang, Li; Tan, Gang; Li, Chao; Hu, Zhian; Wang, Jiali

2015-06-01

Hippocampus-dependent learning memory is sensitive to sleep deprivation (SD). Although the ionotropic glutamate receptors play a vital role in synaptic plasticity and learning and memory, however, whether the expression of these receptor subunits is modulated by sleep loss remains unclear. In the present study, western blotting was performed by probing with specific antibodies against the ionotropic α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor subunits GluA1, GluA2, GluA3, and against the N-methyl-d-aspartate (NMDA) glutamate receptor subunits GluN1, GluN2A, GluN2B. In hippocampus, down regulation of surface GluA1 and GluN2A surface expression were observed in both SD groups. However, surface expression level of GluA2, GluA3, GluN1 and GluN2B was significantly up-regulated in 8h-SD rats when compared to the 4h-SD rats. In parallel with the complex changes in AMPA and NMDA receptor subunit expressions, we found the 8h-SD impaired rat spatial working memory in 30-s-delay T-maze task, whereas no impairment of spatial learning was observed in 4h-SD rats. These results indicate that sleep loss alters the relative expression levels of the AMPA and NMDA receptors, thus affects the synaptic strength and capacity for plasticity and partially contributes to spatial memory impairment. Copyright © 2015. Published by Elsevier B.V.

Structural and computational analysis of intermolecular interactions in a new 2-thiouracil polymorph.

PubMed

Fabijanić, Ivana; Matković-Čalogović, Dubravka; Pilepić, Viktor; Sanković, Krešimir

2017-12-01

The crystallization and characterization of a new polymorph of 2-thiouracil by single-crystal X-ray diffraction, Hirshfeld surface analysis and periodic density functional theory (DFT) calculations are described. The previously published polymorph (A) crystallizes in the triclinic space group P\\overline{1}, while that described herein (B) crystallizes in the monoclinic space group P2 1 /c. Periodic DFT calculations showed that the energies of polymorphs A and B, compared to the gas-phase geometry, were -108.8 and -29.4 kJ mol -1 , respectively. The two polymorphs have different intermolecular contacts that were analyzed and are discussed in detail. Significant differences in the molecular structure were found only in the bond lengths and angles involving heteroatoms that are involved in hydrogen bonds. Decomposition of the Hirshfeld fingerprint plots revealed that O...H and S...H contacts cover over 50% of the noncovalent contacts in both of the polymorphs; however, they are quite different in strength. Hydrogen bonds of the N-H...O and N-H...S types were found in polymorph A, whereas in polymorph B, only those of the N-H...O type are present, resulting in a different packing in the unit cell. QTAIM (quantum theory of atoms in molecules) computational analysis showed that the interaction energies for these weak-to-medium strength hydrogen bonds with a noncovalent or mixed interaction character were estimated to fall within the ranges 5.4-10.2 and 4.9-9.2 kJ mol -1 for polymorphs A and B, respectively. Also, the NCI (noncovalent interaction) plots revealed weak stacking interactions. The interaction energies for these interactions were in the ranges 3.5-4.1 and 3.1-5.5 kJ mol -1 for polymorphs A and B, respectively, as shown by QTAIM analysis.

NADH Dehydrogenase Subunit-2 237 Leu/Met Polymorphism Modulates the Effects of Coffee Consumption on the Risk of Hypertension in Middle-Aged Japanese Men

PubMed Central

Kokaze, Akatsuki; Ishikawa, Mamoru; Matsunaga, Naomi; Karita, Kanae; Yoshida, Masao; Ohtsu, Tadahiro; Shirasawa, Takako; Sekii, Hideaki; Ito, Taku; Kawamoto, Teruyoshi; Takashima, Yutaka

2009-01-01

Background Habitual coffee consumption has been reported to lower blood pressure in the Japanese population. The NADH dehydrogenase subunit-2 237 leucine/methionine (ND2-237 Leu/Met) polymorphism is associated with longevity and modifies the effects of alcohol consumption on blood pressure in the Japanese population. The objective of this study was to determine whether this polymorphism also modifies the effects of coffee consumption on blood pressure or the risk of hypertension in middle-aged Japanese men. Methods A total of 398 men (mean age ± standard deviation, 53.8 ± 7.8 years) were selected from among individuals visiting the hospital for regular medical check-ups. Hypertension was defined as a systolic blood pressure ≥140 mm Hg, diastolic blood pressure ≥90 mm Hg, or antihypertensive drug treatment. Polymerase chain reaction-restriction fragment length polymorphism using the restriction enzyme AluI was performed to determine ND2-237 Leu/Met genotype. Results In subjects with ND2-237Leu, coffee consumption was significantly and negatively associated with diastolic blood pressure (P = 0.007). The odds ratio (OR) for hypertension was significantly lower in subjects with ND2-237Leu who consumed 2 or 3 cups of coffee per day than in those who consumed less than 1 cup of coffee per day (OR, 0.517; 95% confidence interval [CI], 0.276 to 0.968; P = 0.039). After adjustment, the OR remained significant (OR = 0.399; 95% CI, 0.184 to 0.869; P = 0.020). Moreover, after adjustment, the OR was significantly lower in subjects with ND2-237Leu who consumed more than 4 cups of coffee per day than in those who consumed less than 1 cup of coffee per day (OR, 0.246; 95% CI, 0.062 to 0.975; P = 0.046). However, the association between ND2-237Met genotype and hypertension did not depend on coffee consumption. Conclusions The present results suggest that the ND2-237 Leu/Met polymorphism modulates the effects of coffee consumption on hypertension risk in middle-aged Japanese men. PMID:19667492

Association of the widespread A149P hereditary fructose intolerance mutation with newly identified sequence polymorphisms in the aldolase B gene

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brooks, C.C.; Tolan, D.R.

1993-04-01

Hereditary fructose intolerance (HFI) is a potentially fatal autosomal recessive disease resulting from the catalytic deficiency of fructose 1-phosphate aldolase (aldolase B) in fructose-metabolizing tissues. The A149P mutation in exon 5 of the aldolase B gene, located on chromosome 9q2l.3-q22.2, is widespread and the most common HFI mutation, accounting for 57% of HFI chromosomes. The possible origin of this mutation was studied by linkage to polymorphisms within the aldolase B gene. DNA fragments of the aldolase B gene containing the polymorphic marker loci from HFI patients homozygous for the A149P allele were amplified by PCR. Absolute linkage to a commonmore » Pvull RFLP allele was observed in 10 A149P homozygotes. In a more informative study, highly heterozygous polymorphisms were detected by direct sequence determination of a PCR-amplified aldolase B gene fragment. Two two-allele, single-base-pair polymorphisms, themselves in absolute linkage disequilibrium, in intron 8 (C at nucleotide 84 and A at nucleotide 105, or T at 84 and G at 105) of the aldolase B gene were identified. Mendelian segregation of these polymorphisms was confirmed in three families. Allele-specific oligonucleotide (ASO) hybridizations with probes for both sequence polymorphisms showed that 47% of 32 unrelated individuals were heterozygous at these loci; the calculated PIC value was .37. Finally, ASO hybridizations of PCR-amplified DNA from 15 HFI patients homozygous for the A149P allele with probes for these sequence polymorphisms revealed absolute linkage disequilibrium between the A149P mutation and the 84T/105G allele. These results are consistent with a single origin of the A149P allele and subsequent spread by genetic drift. 32 refs., 4 figs., 3 tabs.« less

Rapid and cost-effective method for the detection of the c.533G>A mutation in the HEXA gene.

PubMed

Ribeiro, Diogo; Duarte, Ana Joana; Amaral, Olga

2011-03-01

Tay-Sachs disease is a rare autosomal recessive neurodegenerative disorder that results from mutations in the HEXA gene, leading to β-hexosaminidase A (HexA) α subunit deficiency. An unusual variant of Tay-Sachs disease is known as the B1 variant. Previous studies indicated that, in northern Portugal, this is not only the most common variant but also one of the most prevalent lysosomal storage diseases. Additionally, this variant might also show a higher prevalence in populations of Portuguese and Spanish ancestry. A single mutation is invariably present in at least one of the alleles of B1 variant patients, HEXA mutation c.533G >A. To implement a method for c.533G >A testing in individuals and populations, we have optimized two distinct mutation analysis techniques, one based on restriction fragment length polymorphism analysis and the other based on allelic discrimination. We present the comparison of both methods and their advantages. Mutation screening by allelic discrimination proved to be particularly useful for the studying of large samples of individuals. It is time saving and highly reproducible, and under the conditions used, its cost is lower than the cost of polymerase chain reaction-based restriction fragment length polymorphism analysis.

Up-regulation of Hyperpolarization-activated Cyclic Nucleotide-gated Channel 3 (HCN3) by Specific Interaction with K+ Channel Tetramerization Domain-containing Protein 3 (KCTD3)*

PubMed Central

Cao-Ehlker, Xiaochun; Zong, Xiangang; Hammelmann, Verena; Gruner, Christian; Fenske, Stefanie; Michalakis, Stylianos; Wahl-Schott, Christian; Biel, Martin

2013-01-01

Most ion channels consist of the principal ion-permeating core subunit(s) and accessory proteins that are assembled with the channel core. The biological functions of the latter proteins are diverse and include the regulation of the biophysical properties of the ion channel, its connection to signaling pathways and the control of its cell surface expression. There is recent evidence that native hyperpolarization-activated cyclic nucleotide-gated channel complexes (HCN1–4) also contain accessory subunits, among which TRIP8b (tetratricopeptide repeat-containing Rab8b-interacting protein) has been most extensively studied. Here, we identify KCTD3, a so far uncharacterized member of the potassium channel tetramerization-domain containing (KCTD) protein family as an HCN3-interacting protein. KCTD3 is widely expressed in brain and some non-neuronal tissues and colocalizes with HCN3 in specific regions of the brain including hypothalamus. Within the HCN channel family, KCTD3 specifically binds to HCN3 and leads to a profound up-regulation of cell surface expression and current density of this channel. HCN3 can also functionally interact with TRIP8b; however, we found no evidence for channel complexes containing both TRIP8b and KCTD3. The C terminus of HCN3 is crucially required for functional interaction with KCTD3. Replacement of the cytosolic C terminus of HCN2 by the corresponding domain of HCN3 renders HCN2 sensitive to regulation by KCTD3. The C-terminal-half of KCTD3 is sufficient for binding to HCN3. However, the complete protein including the N-terminal tetramerization domain is needed for HCN3 current up-regulation. Together, our experiments indicate that KCTD3 is an accessory subunit of native HCN3 complexes. PMID:23382386

Diversity in genomic organisation, developmental regulation and distribution of the murine PR72/B" subunits of protein phosphatase 2A

PubMed Central

Zwaenepoel, Karen; Louis, Justin V; Goris, Jozef; Janssens, Veerle

2008-01-01

Background Protein phosphatase 2A (PP2A) is a serine/threonine-specific phosphatase displaying vital functions in growth and development through its role in various signalling pathways. PP2A holoenzymes comprise a core dimer composed of a catalytic C and a structural A subunit, which can associate with a variable B-type subunit. The importance of the B-type subunits for PP2A regulation cannot be overestimated as they determine holoenzyme localisation, activity and substrate specificity. Three B-type subunit families have been identified: PR55/B, PR61/B' and PR72/B", of which the latter is currently the least characterised. Results We deduced the sequences and genomic organisation of the different murine PR72/B" isoforms: three genes encode nine isoforms, five of which are abundantly expressed and give rise to genuine PP2A subunits. Thereby, one novel subunit was identified. Using Northern blotting, we examined the tissue-specific and developmental expression of these subunits. All subunits are highly expressed in heart, suggesting an important cardiac function. Immunohistochemical analysis revealed a striated expression pattern of PR72 and PR130 in heart and skeletal muscle, but not in bladder smooth muscle. The subcellular localisation and cell cycle regulatory ability of several PR72/B" isoforms were determined, demonstrating differences as well as similarities. Conclusion In contrast to PR55/B and PR61/B', the PR72/B" family seems evolutionary more divergent, as only two of the murine genes have a human orthologue. We have integrated these results in a more consistent nomenclature of both human and murine PR72/B" genes and their transcripts/proteins. Our results provide a platform for the future generation of PR72/B" knockout mice. PMID:18715506

Ribo HRM--detection of inter- and intra-species polymorphisms within ribosomal DNA by high resolution melting analysis supported by application of artificial allelic standards.

PubMed

Masny, Aleksander; Jagiełło, Agata; Płucienniczak, Grażyna; Golab, Elzbieta

2012-09-01

Ribo HRM, a single-tube PCR and high resolution melting (HRM) assay for detection of polymorphisms in the large subunit ribosomal DNA expansion segment V, was developed on a Trichinella model. Four Trichinella species: T. spiralis (isolates ISS3 and ISS160), T. nativa (isolates ISS10 and ISS70), T. britovi (isolates ISS2 and ISS392) and T. pseudospiralis (isolates ISS13 and ISS1348) were genotyped. Cloned allelic variants of the expansion segment V were used as standards to prepare reference HRM curves characteristic for single sequences and mixtures of several cloned sequences imitating allelic composition detected in Trichinella isolates. Using the primer pair Tsr1 and Trich1bi, it was possible to amplify a fragment of the ESV and detect PCR products obtained from the genomic DNA of pools of larvae belonging to the four investigated species: T. pseudospiralis, T. spiralis, T. britovi and T. nativa, in a single tube Real-Time PCR reaction. Differences in the shape of the HRM curves of Trichinella isolates suggested the presence of differences between examined isolates of T. nativa, T. britovi and T. pseudospiralis species. No differences were observed between T. spiralis isolates. The presence of polymorphisms within the amplified ESV sequence fragment of T. nativa T. britovi and T. pseudospiralis was confirmed by sequencing of the cloned PCR products. Novel sequences were discovered and deposited in GenBank (GenBank IDs: JN971020-JN971027, JN120902.1, JN120903.1, JN120904.1, JN120906.1, JN120905.1). Screening the ESV region of Trichinella for polymorphism is possible using the genotyping assay Ribo HRM at the current state of its development. The Ribo HRM assay could be useful in phylogenetic studies of the Trichinella genus. Copyright © 2012 Elsevier B.V. All rights reserved.

Memory in aged mice is rescued by enhanced expression of the GluN2B subunit of the NMDA receptor

PubMed Central

Brim, B. L.; Haskell, R.; Awedikian, R.; Ellinwood, N.M.; Jin, L.; Kumar, A.; Foster, T.C.; Magnusson, K.

2012-01-01

The GluN2B subunit of the N-methyl-D-aspartate (NMDA) receptor shows age-related declines in expression across the frontal cortex and hippocampus. This decline is strongly correlated to age-related memory declines. This study was designed to determine if increasing GluN2B subunit expression in the frontal lobe or hippocampus would improve memory in aged mice. Mice were injected bilaterally with either the GluN2B vector, containing cDNA specific for the GluN2B subunit and enhanced Green Fluorescent Protein (eGFP); a control vector or vehicle. Spatial memory, cognitive flexibility, and associative memory were assessed using the Morris water maze. Aged mice, with increased GluN2B subunit expression, exhibited improved long-term spatial memory, comparable to young mice. However, memory was rescued on different days in the Morris water maze; early for hippocampal GluN2B subunit enrichment and later for the frontal lobe. A higher concentration of the GluN2B antagonist, Ro 25-6981, was required to impair long-term spatial memory in aged mice with enhanced GluN2B expression, as compared to aged controls, suggesting there was an increase in the number of GluN2B-containing NMDA receptors. In addition, hippocampal slices from aged mice with increased GluN2B subunit expression exhibited enhanced NMDA receptor-mediated excitatory post-synaptic potentials (EPSP). Treatment with Ro 25-6981 showed that a greater proportion of the NMDA receptor-mediated EPSP was due to the GluN2B subunit in these animals, as compared to aged controls. These results suggest that increasing the production of the GluN2B subunit in aged animals enhances memory and synaptic transmission. Therapies that enhance GluN2B subunit expression within the aged brain may be useful for ameliorating age-related memory declines. PMID:23103326

In vivo particle polymorphism results from deletion of a N-terminal peptide molecular switch in brome mosaic virus capsid protein

PubMed Central

Calhoun, Shauni L; Speir, Jeffrey A; Rao, A.L.N.

2009-01-01

The interaction between brome mosaic virus (BMV) coat protein (CP) and viral RNA is a carefully orchestrated process resulting in the formation of homogeneous population of infectious virions with T=3 symmetry. Expression in vivo of either wild type or mutant BMV CP through homologous replication never results in the assembly of aberrant particles. In this study, we report that deletion of amino acid residues 41–47 from the N-proximal region of BMV CP resulted in the assembly of polymorphic virions in vivo. Purified virions from symptomatic leaves remain non-infectious and Northern blot analysis of virion RNA displayed packaging defects. Biochemical of variant CP by circular dichroism and MALDI-TOF, respectively, revealed that the engineered deletion affected the protein structure and capsid dynamics. Most significantly, CP subunits dissociated from polymorphic virions are incompetent for in vitro reassembly. Based on these observations, we propose a chaperon mediated mechanism for the assembly of variant CP in vivo and also hypothesize that 41KAIKAIA47 N-proximal peptide functions as a molecular switch in regulating T= 3 virion symmetry. PMID:17449079

DNA methyltransferase 3A promoter polymorphism is associated with the risk of human spontaneous abortion after assisted reproduction techniques and natural conception.

PubMed

Liu, Yudong; Zheng, Haiyan; Guo, Pingping; Feng, Shuxian; Zhou, Xingyu; Ye, Desheng; Chen, Xin; Chen, Shiling

2017-02-01

The aim of this study was to explore the association of the DNA-methyltransferase (DNMT)-3A and DNMT3B promoter polymorphisms with the risk of human spontaneous abortion after assisted reproduction techniques (ARTs) and natural conception. We collected tissues from women who underwent abortion procedures: (a) chorionic villus samples (CVS) and muscle samples (MS) from spontaneous abortions conceived by ART and natural cycle (study group), n = 152; and (b) CVS and MS from normal early pregnancy and second trimester (control group), n = 155. The single-nucleotide polymorphism (SNP) -448A > G in the DNMT3A promoter region and -149C/T polymorphism of DNMT3B were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and confirmed by sequencing. The allele frequency of -448A among pregnancy loss group and control group was 34.2 % vs. 16.5 %, respectively. Compared with GG carriers, the DNMT3A -448AA homozygotes had an about 16-fold increased risk of spontaneous abortion [odds ratio (OR) = 16.130, 95 % confidence interval (CI), 3.665-70.984], and AG heterozygotes had an OR of 2.027 (95 % CI, 1.247-3.293). However, the distribution of -448A > G in individuals derived from ART pregnancies was not statistically significantly compared with those derived from spontaneous pregnancies (P = 0.661). For DNMT3B, we observed genotype frequencies of 100 % (TT) in the study group and the control group. The DNMT3A -448A > G polymorphism may be a novel functional SNP and contribute to its genetic susceptibility to spontaneous abortion in Chinese women, and ART may not affect the distribution of -448A > G in pregnancy loss and normal pregnancy. The observed TT genotype of DMNT3B suggests that this is the predominant genotype of this population. The findings provide new insights into the etiology of human spontaneous abortion.

Association of Neuropeptide-Y (NPY) and Interleukin-1beta (IL1B), Genotype-Phenotype Correlation and Plasma Lipids with Type-II Diabetes

PubMed Central

Mansuri, Mohmmad Shoab; Ansarullah; Laddha, Naresh C.; Thakker, Ami; Ramachandran, A. V.; Begum, Rasheedunnisa

2016-01-01

Background Neuropeptide Y (NPY) is known to play a role in the regulation of satiety, energy balance, body weight, and insulin release. Interleukin-1beta (IL1B) has been associated with loss of beta-cell mass in type-II diabetes (TIID). Objectives The present study attempts to investigate the association of NPY exon2 +1128 T/C (Leu7Pro; rs16139), NPY promoter -399 T/C (rs16147) and IL1B -511 C/T (rs16944) polymorphisms with TIID and their correlation with plasma lipid levels, BMI, and IL1B transcript levels. Methods PCR-RFLP was used for genotyping these polymorphisms in a case-control study involving 558 TIID patients and 1085 healthy age-matched controls from Gujarat. Linkage disequilibrium and haplotype analysis of the NPY polymorphic sites were performed to assess their association with TIID. IL1B transcript levels in PBMCs were also assessed in 108 controls and 101 patients using real-time PCR. Results Our results show significant association of both structural and promoter polymorphisms of NPY (p<0.0001 and p<0.0001 respectively) in patients with TIID. However, the IL1B C/T polymorphism did not show any association (p = 0.3797) with TIID patients. Haplotype analysis revealed more frequent association of CC and CT haplotypes (p = 3.34 x 10−5, p = 6.04 x 10−9) in diabetics compared to controls and increased the risk of diabetes by 3.02 and 2.088 respectively. Transcript levels of IL1B were significantly higher (p<0.0001) in patients as compared to controls. Genotype-phenotype correlation of IL1B polymorphism did not show any association with its higher transcript levels. In addition, NPY +1128 T/C polymorphism was found to be associated with increased plasma LDL levels (p = 0.01). Conclusion The present study provides an evidence for a strong correlation between structural and promoter polymorphisms of NPY gene and upregulation of IL1B transcript levels with susceptibility to TIID and altering the lipid metabolism in Gujarat population. PMID:27749914

Association of Neuropeptide-Y (NPY) and Interleukin-1beta (IL1B), Genotype-Phenotype Correlation and Plasma Lipids with Type-II Diabetes.

PubMed

Patel, Roma; Dwivedi, Mitesh; Mansuri, Mohmmad Shoab; Ansarullah; Laddha, Naresh C; Thakker, Ami; Ramachandran, A V; Begum, Rasheedunnisa

2016-01-01

Neuropeptide Y (NPY) is known to play a role in the regulation of satiety, energy balance, body weight, and insulin release. Interleukin-1beta (IL1B) has been associated with loss of beta-cell mass in type-II diabetes (TIID). The present study attempts to investigate the association of NPY exon2 +1128 T/C (Leu7Pro; rs16139), NPY promoter -399 T/C (rs16147) and IL1B -511 C/T (rs16944) polymorphisms with TIID and their correlation with plasma lipid levels, BMI, and IL1B transcript levels. PCR-RFLP was used for genotyping these polymorphisms in a case-control study involving 558 TIID patients and 1085 healthy age-matched controls from Gujarat. Linkage disequilibrium and haplotype analysis of the NPY polymorphic sites were performed to assess their association with TIID. IL1B transcript levels in PBMCs were also assessed in 108 controls and 101 patients using real-time PCR. Our results show significant association of both structural and promoter polymorphisms of NPY (p<0.0001 and p<0.0001 respectively) in patients with TIID. However, the IL1B C/T polymorphism did not show any association (p = 0.3797) with TIID patients. Haplotype analysis revealed more frequent association of CC and CT haplotypes (p = 3.34 x 10-5, p = 6.04 x 10-9) in diabetics compared to controls and increased the risk of diabetes by 3.02 and 2.088 respectively. Transcript levels of IL1B were significantly higher (p<0.0001) in patients as compared to controls. Genotype-phenotype correlation of IL1B polymorphism did not show any association with its higher transcript levels. In addition, NPY +1128 T/C polymorphism was found to be associated with increased plasma LDL levels (p = 0.01). The present study provides an evidence for a strong correlation between structural and promoter polymorphisms of NPY gene and upregulation of IL1B transcript levels with susceptibility to TIID and altering the lipid metabolism in Gujarat population.

A Minimal Anaphase Promoting Complex/Cyclosome (APC/C) in Trypanosoma brucei

PubMed Central

Bessat, Mohamed; Knudsen, Giselle; Burlingame, Alma L.; Wang, Ching C.

2013-01-01

The anaphase-promoting complex/cyclosome (APC/C) is a multi-subunit E3 ubiquitin ligase that initiates chromosome segregation and mitotic exit by targeting critical cell-cycle regulators for proteolytic destruction. Previously, seven APC/C subunit homologues were identified in the genome of Trypanosoma brucei. In the present study, we tested five of them in yeast complementation studies and found none of them capable of complementing the yeast mutants lacking the corresponding subunits, suggesting significant discrepancies between the two APC/C’s. Subunit homologues of mitotic checkpoint complex (MCC) have not yet been identified in T. brucei, raising the possibility that a MCC-APC/C complex equivalent may not exist in T. brucei. We performed tandem affinity purification of the protein complex containing a APC1 fusion protein expressed in the cells enriched in different phases of the cell cycle of procyclic form T. brucei, and compared their protein profiles using LC-MS/MS analyses. The seven putative APC/C subunits were identified in the protein complex throughout the cell cycle together with three additional proteins designated the associated proteins (AP) AP1, AP2 and AP3. Abundance of the 10 proteins remained relatively unchanged throughout the cell cycle, suggesting that they are the core subunits of APC/C. AP1 turned out to be a homologue of APC4. An RNAi knockdown of APC4 and AP3 showed no detectable cellular phenotype, whereas an AP2 knockdown enriched the cells in G2/M phase. The AP2-depleted cells showed stabilized mitotic cyclin B. An accumulation of poly-ubiquitinated cyclin B was indicated in the cells treated with the proteasome inhibitor MG132, demonstrating the involvement of proteasome in degrading poly-ubiquitinated cyclin B. In all, a 10-subunit APC/C machinery with a conserved function is identified in T. brucei without linking to a MCC-like complex, thus indicating a unique T. brucei APC/C. PMID:23533609

Concholepas concholepas Ferritin H-like subunit (CcFer): Molecular characterization and single nucleotide polymorphism associated to innate immune response.

PubMed

Chávez-Mardones, Jacqueline; Valenzuela-Muñoz, Valentina; Núñez-Acuña, Gustavo; Maldonado-Aguayo, Waleska; Gallardo-Escárate, Cristian

2013-09-01

Ferritin has been identified as the principal protein of iron storage and iron detoxification, playing a pivotal role for the cellular homeostasis in living organisms. However, recent studies in marine invertebrates have suggested its association with innate immune system. In the present study, one Ferritin subunit was identified from the gastropod Concholepas concholepas (CcFer), which was fully characterized by Rapid Amplification of cDNA Ends technique. Simultaneously, a challenge test was performed to evaluate the immune response against Vibrio anguillarum. The full length of cDNA Ccfer was 1030 bp, containing 513 bp of open reading frame that encodes to 170 amino acid peptide, which was similar to the Ferritin H subunit described in vertebrates. Untranslated Regions (UTRs) were identified with a 5'UTR of 244 bp that contains iron responsive element (IRE), and a 3'UTR of 273 bp. The predicted molecular mass of deduced amino acid of CcFer was 19.66 kDa and isoelectric point of 4.92. Gene transcription analysis revealed that CcFer increases against infections with V. anguillarum, showing a peak expression at 6 h post-infection. Moreover, a single nucleotide polymorphism was detected at -64 downstream 5'UTR sequence (SNP-64). Quantitative real time analysis showed that homozygous mutant allele (TT) was significantly associated with higher expression levels of the challenged group compared to wild (CC) and heterozygous (CT) variants. Our findings suggest that CcFer is associated to innate immune response in C. concholepas and that the presence of SNPs may involve differential transcriptional expression of CcFer. Copyright © 2013 Elsevier Ltd. All rights reserved.

The molecular epidemiology of cholera in Latin America.

PubMed

Wachsmuth, I K; Evins, G M; Fields, P I; Olsvik, O; Popovic, T; Bopp, C A; Wells, J G; Carrillo, C; Blake, P A

1993-03-01

To explain the sudden appearance and rapid spread of cholera in Latin America in January 1991, molecular techniques were used to define Vibrio cholerae O1 isolates from around the world. Restriction fragment length polymorphisms of rRNA and ctxA genes, DNA sequence of cholera toxin B subunit gene ctxB, and multilocus enzyme electrophoresis data were used to characterize 197 isolates. Worldwide, there are at least four distinct toxigenic El Tor V. cholerae O1 clones: the seventh pandemic (Eastern Hemisphere), US Gulf Coast, Australian, and Latin American. Nontoxigenic V. cholerae O1 previously isolated in Brazil, Mexico, and Peru are unlike current toxigenic isolates. The Latin American clone probably represents an extension of the seventh pandemic into the Western Hemisphere, while the US Gulf Coast clone most likely evolved separately. These data will be useful in monitoring the spread of cholera, determining the origin of outbreaks in both hemispheres, and implicating specific vehicles of transmission.

α5 nAChR modulation of the prefrontal cortex makes attention resilient.

PubMed

Howe, William M; Brooks, Julie L; Tierney, Patrick L; Pang, Jincheng; Rossi, Amie; Young, Damon; Dlugolenski, Keith; Guillmette, Ed; Roy, Marc; Hales, Katherine; Kozak, Rouba

2018-03-01

A loss-of-function polymorphism in the α5 nicotinic acetylcholine receptor (nAChR) subunit gene has been linked to both drug abuse and schizophrenia. The α5 nAChR subunit is strategically positioned in the prefrontal cortex (PFC), where a loss-of-function in this subunit may contribute to cognitive disruptions in both disorders. However, the specific contribution of α5 to PFC-dependent cognitive functions has yet to be illustrated. In the present studies, we used RNA interference to knockdown the α5 nAChR subunit in the PFC of adult rats. We provide evidence that through its contribution to cholinergic modulation of cholinergic modulation of neurons in the PFC, the α5 nAChR plays a specific role in the recovery of attention task performance following distraction. Our combined data reveal the potent ability of this subunit to modulate the PFC and cognitive functions controlled by this brain region that are impaired in disease.

Interaction of IL1B and IL1RN polymorphisms, smoking habit, gender, and ethnicity with aggressive and chronic periodontitis susceptibility.

PubMed

Ribeiro, Magali Silveira Monteiro; Pacheco, Renata Botelho Antunes; Fischer, Ricardo Guimarães; Macedo, Jacyara Maria Brito

2016-01-01

Although the interleukin-1 (IL-1) plays a critical role in the pathogenesis of periodontitis, associations between IL1 gene cluster polymorphisms and the disease remains unclear. To investigate the importance of IL1B-511C>T (rs16944), IL1B +3954C>T (rs1143634), and IL1RN intron 2 variable number tandem repeat (VNTR) (rs2234663) polymorphisms, individually or in combination, as the risk factors of periodontitis in a Southeastern Brazilian population with a high degree of miscegenation. A total of 145 individuals, with aggressive (aggressive periodontitis [AgP], n = 43) and chronic (chronic periodontitis [CP], n = 52) periodontitis, and controls (n = 50) were genotyped by polymerase chain reaction (PCR) (IL1RN intron 2 VNTR) or PCR-restriction fragment length polymorphism (PCR-RFLP) (IL1B-511 C>T and IL1B + 3954C>T) techniques. The independent t-test, Chi-square, and Fisher's exact tests were used. The SNPStats program was used for haplotype estimation and multiplicative interaction analyses. The IL1B +3954T allele represented risk for CP (odds ratio [OR] = 2.84), particularly in smokers (OR = 4.43) and females (OR = 6.00). The minor alleles IL1RN*2 and *3 increased the risk of AgP (OR = 2.18), especially the IL1RN*2*2 genotype among  white Brazilians (OR = 7.80). Individuals with the combinations of the IL1B + 3954T and IL1RN*2 or *3-containing genotypes were at increased risk of developing CP (OR = 4.50). Considering the three polymorphisms (rs16944, rs1143634, and rs2234663), the haplotypes TC2 and CT1 represented risk for AgP (OR = 3.41) and CP (OR = 6.39), respectively. Our data suggest that the IL1B +3954C>T and IL1RN intron 2 VNTR polymorphisms are potential candidates for genetic biomarkers of periodontitis, particularly in specific groups of individuals.

The role of GluN2B-containing NMDA receptors in short- and long-term fear recall.

PubMed

Mikics, Eva; Toth, Mate; Biro, Laszlo; Bruzsik, Biborka; Nagy, Boglarka; Haller, Jozsef

2017-08-01

N-methyl-d-aspartate (NMDA) receptors are crucial synaptic elements in long-term memory formation, including the associative learning of fearful events. Although NMDA blockers were consistently shown to inhibit fear memory acquisition and recall, the clinical use of general NMDA blockers is hampered by their side effects. Recent studies revealed significant heterogeneity in the distribution and neurophysiological characteristics of NMDA receptors with different GluN2 (NR2) subunit composition, which may have differential role in fear learning and recall. To investigate the specific role of NMDA receptor subpopulations with different GluN2 subunit compositions in the formation of lasting traumatic memories, we contrasted the effects of general NMDA receptor blockade with GluN2A-, GluN2B-, and GluN2C/D subunit selective antagonists (MK-801, PEAQX, Ro25-6981, PPDA, respectively). To investigate acute and lasting consequences, behavioral responses were investigated 1 and 28days after fear conditioning. We found that MK-801 (0.05 and 0.1mg/kg) decreased fear recall at both time points. GluN2B receptor subunit blockade produced highly similar effects, albeit efficacy was somewhat smaller 28days after fear conditioning. Unlike MK-801, Ro25-6981 (3 and 10mg/kg) did not affect locomotor activity in the open-field. In contrast, GluN2A and GluN2C/D blockers (6 and 20mg/kg PEAQX; 3 and 10mg/kg PPDA, respectively) had no effect on conditioned fear recall at any time point and dose. This sharp contrast between GluN2B- and other subunit-containing NMDA receptor function indicates that GluN2B receptor subunits are intimately involved in fear memory formation, and may provide a novel pharmacological target in post-traumatic stress disorder or other fear-related disorders. Copyright © 2017 Elsevier Inc. All rights reserved.

Suppression of the heterotrimeric G protein causes abnormal morphology, including dwarfism, in rice

PubMed Central

Fujisawa, Yukiko; Kato, Teruhisa; Ohki, Shizuka; Ishikawa, Atsushi; Kitano, Hidemi; Sasaki, Takuji; Asahi, Tadashi; Iwasaki, Yukimoto

1999-01-01

Transgenic rice containing an antisense cDNA for the α subunit of rice heterotrimeric G protein produced little or no mRNA for the subunit and exhibited abnormal morphology, including dwarf traits and the setting of small seeds. In normal rice, the mRNA for the α subunit was abundant in the internodes and florets, the tissues closely related to abnormality in the dwarf transformants. The position of the α-subunit gene was mapped on rice chromosome 5 by mapping with the restriction fragment length polymorphism. The position was closely linked to the locus of a rice dwarf mutant, Daikoku dwarf (d-1), which is known to exhibit abnormal phenotypes similar to those of the transformants that suppressed the endogenous mRNA for the α subunit by antisense technology. Analysis of the cDNAs for the α subunits of five alleles of Daikoku dwarf (d-1), ID-1, DK22, DKT-1, DKT-2, and CM1361–1, showed that these dwarf mutants had mutated in the coding region of the α-subunit gene. These results show that the G protein functions in the formation of normal internodes and seeds in rice. PMID:10377457

Crystal structure of heterodimeric hexaprenyl diphosphate synthase from Micrococcus luteus B-P 26 reveals that the small subunit is directly involved in the product chain length regulation.

PubMed

Sasaki, Daisuke; Fujihashi, Masahiro; Okuyama, Naomi; Kobayashi, Yukiko; Noike, Motoyoshi; Koyama, Tanetoshi; Miki, Kunio

2011-02-04

Hexaprenyl diphosphate synthase from Micrococcus luteus B-P 26 (Ml-HexPPs) is a heterooligomeric type trans-prenyltransferase catalyzing consecutive head-to-tail condensations of three molecules of isopentenyl diphosphates (C(5)) on a farnesyl diphosphate (FPP; C(15)) to form an (all-E) hexaprenyl diphosphate (HexPP; C(30)). Ml-HexPPs is known to function as a heterodimer of two different subunits, small and large subunits called HexA and HexB, respectively. Compared with homooligomeric trans-prenyltransferases, the molecular mechanism of heterooligomeric trans-prenyltransferases is not yet clearly understood, particularly with respect to the role of the small subunits lacking the catalytic motifs conserved in most known trans-prenyltransferases. We have determined the crystal structure of Ml-HexPPs both in the substrate-free form and in complex with 7,11-dimethyl-2,6,10-dodecatrien-1-yl diphosphate ammonium salt (3-DesMe-FPP), an analog of FPP. The structure of HexB is composed of mostly antiparallel α-helices joined by connecting loops. Two aspartate-rich motifs (designated the first and second aspartate-rich motifs) and the other characteristic motifs in HexB are located around the diphosphate part of 3-DesMe-FPP. Despite the very low amino acid sequence identity and the distinct polypeptide chain lengths between HexA and HexB, the structure of HexA is quite similar to that of HexB. The aliphatic tail of 3-DesMe-FPP is accommodated in a large hydrophobic cleft starting from HexB and penetrating to the inside of HexA. These structural features suggest that HexB catalyzes the condensation reactions and that HexA is directly involved in the product chain length control in cooperation with HexB.

Promoter polymorphisms of ST3GAL4 and ST6GAL1 genes and associations with risk of premalignant and malignant lesions of the cervix.

PubMed

Rivera-Juarez, Maria de Los Angeles; Rosas-Murrieta, Nora Hilda; Mendieta-Carmona, Victoriano; Hernandez-Pacheco, Raquel Esneidy; Zamora-Ginez, Irma; Rodea-Avila, Carlos; Apresa-Garcia, Teresa; Garay-Villar, Onix; Aguilar-Lemarroy, Adriana; Jave-Suarez, Luis Felipe; Diaz-Orea, Maria Alicia; Milflores-Flores, Lorena; Reyes-Salinas, Juan Salvador; Ceja-Utrera, Francisco Javier; Vazquez-Zamora, Victor Javier; Vargas-Maldonado, Tomas; Reyes-Carmona, Sandra; Sosa-Jurado, Francisca; Santos-Lopez, Gerardo; Reyes-Leyva, Julio; Vallejo-Ruiz, Veronica

2014-01-01

Sialyltransferase gene expression is altered in several cancers, including examples in the cervix. Transcriptional regulation of the responsible genes depends on different promoters. We aimed to determine the association of single-nucleotide polymorphisms in the B3 promoter of the ST3GAL4 gene and the P1 promoter of the ST6GAL1 gene with cervical premalignant lesions or cervical cancer. A blood sample and/or cervical scrapes were obtained from 104 women with normal cytology, 154 with premalignant lesions and 100 with cervical cancer. We also included 119 blood samples of random donors. The polymorphisms were identified by sequencing from PCR products. For the B3 promoter, a fragment of 506 bp (from nucleotide -408 to +98) was analyzed, and for the P1 promoter a 490 bp (-326 to +164) fragment. The polymorphism analysis showed that at SNP rs10893506, genotypes CC and CT of the ST3GAL4 B3 promoter were associated with the presence of premalignant lesions (OR=2.89; 95%CI 1.72-4.85) and cervical cancer (OR=2.23; 95%CI 1.27-3.91). We detected only one allele of each polymorphism in the ST6GAL1 P1 promoter. We did not detect any genetic variability in the P1 promoter region in our study population. Our results suggest that the rs10893506 polymorphism -22C/T may increase susceptibility to premalignant and malignant lesions of the cervix.

Presence of the p.L456V polymorphism in Cuban patients clinically diagnosed with Wilson's disease.

PubMed

Clark-Feoktistova, Y; Ruenes-Domech, C; García-Bacallao, E F; Roblejo-Balbuena, H; Feoktistova, L; Clark-Feoktistova, I; Jay-Herrera, O; Collazo-Mesa, T

2018-06-10

Wilson's disease is characterized by the accumulation of copper in different organs, mainly affecting the liver, brain, and cornea, and is caused by mutations in the ATP7B gene. More than 120 polymorphisms in the ATP7B gene have been reported in the medical literature. The aim of the present study was to identify the conformational changes in the exon 3 region of the ATP7B gene and detect the p.L456V polymorphism in Cuban patients clinically diagnosed with Wilson's disease. A descriptive study was conducted at the Centro Nacional de Genética Médica and the Instituto Nacional de Gastroenterología within the time frame of 2007-2012 and included 105 patients with a clinical diagnosis of Wilson's disease. DNA extraction was performed through the salting-out method and the fragment of interest was amplified using the polymerase chain reaction technique. The conformational shift changes in the exon 3 region and the presence of the p.L456V polymorphism were identified through the Single-Strand Conformation Polymorphism analysis. The so-called b and c conformational shift changes, corresponding to the p.L456V polymorphism in the heterozygous and homozygous states, respectively, were identified. The allelic frequency of the p.L456V polymorphism in the 105 Cuban patients that had a clinical diagnosis of Wilson's disease was 41% and liver-related symptoms were the most frequent in the patients with that polymorphism. The p.L456V polymorphism was identified in 64 Cuban patients clinically diagnosed with Wilson's disease, making future molecular study through indirect methods possible. Copyright © 2018 Asociación Mexicana de Gastroenterología. Publicado por Masson Doyma México S.A. All rights reserved.

Characterization of Hybrid Toluate and Benzoate Dioxygenases

PubMed Central

Ge, Yong; Eltis, Lindsay D.

2003-01-01

Toluate dioxygenase of Pseudomonas putida mt-2 (TADOmt2) and benzoate dioxygenase of Acinetobacter calcoaceticus ADP1 (BADOADP1) catalyze the 1,2-dihydroxylation of different ranges of benzoates. The catalytic component of these enzymes is an oxygenase consisting of two subunits. To investigate the structural determinants of substrate specificity in these ring-hydroxylating dioxygenases, hybrid oxygenases consisting of the α subunit of one enzyme and the β subunit of the other were prepared, and their respective specificities were compared to those of the parent enzymes. Reconstituted BADOADP1 utilized four of the seven tested benzoates in the following order of apparent specificity: benzoate > 3-methylbenzoate > 3-chlorobenzoate > 2-methylbenzoate. This is a significantly narrower apparent specificity than for TADOmt2 (3-methylbenzoate > benzoate ∼ 3-chlorobenzoate > 4-methylbenzoate ∼ 4-chlorobenzoate ≫ 2-methylbenzoate ∼ 2-chlorobenzoate [Y. Ge, F. H. Vaillancourt, N. Y. Agar, and L. D. Eltis, J. Bacteriol. 184:4096-4103, 2002]). The apparent substrate specificity of the αBβT hybrid oxygenase for these benzoates corresponded to that of BADOADP1, the parent from which the α subunit originated. In contrast, the apparent substrate specificity of the αTβB hybrid oxygenase differed slightly from that of TADOmt2 (3-chlorobenzoate > 3-methylbenzoate > benzoate ∼ 4-methylbenzoate > 4-chlorobenzoate > 2-methylbenzoate > 2-chlorobenzoate). Moreover, the αTβB hybrid catalyzed the 1,6-dihydroxylation of 2-methylbenzoate, not the 1,2-dihydroxylation catalyzed by the TADOmt2 parent. Finally, the turnover of this ortho-substituted benzoate was much better coupled to O2 utilization in the hybrid than in the parent. Overall, these results support the notion that the α subunit harbors the principal determinants of specificity in ring-hydroxylating dioxygenases. However, they also demonstrate that the β subunit contributes significantly to the enzyme's function. PMID:12949084

The DNA Methyltransferase 3B -149 Genetic Polymorphism Modulates Lung Cancer Risk from Smoking

PubMed Central

Lai, Chung Yu; Huang, Chia Chen; Tsai, Chin Hung; Wang, Jiun Yao; Kerr, Chih Ling; Chen, Yi Yu; Cai, Yan Wei; Wong, Ruey Hong

2017-01-01

Background: Smoking can cause increase of DNA methylation and hypermethylation of tumor suppressor genes, this possible contributing to subsequent lung cancer development. DNA methyltransferase 3B (DNMT3B) is crucial in regulation of DNA methylation and it has been proposed that green tea might lower cancer risk through inhibiting its activity. Here, we designed a case-control study to investigate whether the DNMT3B -149 genetic polymorphism could modulate lung cancer risk due to smoking. Possible interactions of smoking and green tea consumption with this DNMT3B genetic polymorphism were also assessed. Materials and Methods: A total of 190 lung cancer patients and 380 healthy controls were recruited. Questionnaires were administered to obtain data on sociodemographic and lifestyle variables, as well as family history of lung cancer. Genotypes for DNMT3B -149 were identified by polymerase chain reaction. Results: Smoking, green tea consumption, exposure to cooking fumes, family history of lung cancer, and the DNMT3B -149 genotype (odds ratio (OR)=2.65; 95% confidence interval (CI) 1.15-6.10) were all significantly associated with the development of lung cancer. Smokers carrying the DNMT3B -149 TT genotype were at elevated risk compared to non-smokers carrying DNMT3B -149 (OR=7.69; 95% CI 2.55-23.14). Interaction of smoking with DNMT3B -149 genotypes was significant regarding lung cancer risk. However, interaction between green tea drinking and DNMT3B -149 genotypes was not. Conclusions: The DNMT3B -149 TT genotype might increase the smoking-associated lung cancer risk. PMID:29072397

Human Pol ζ purified with accessory subunits is active in translesion DNA synthesis and complements Pol η in cisplatin bypass

PubMed Central

Lee, Young-Sam; Gregory, Mark T.; Yang, Wei

2014-01-01

DNA polymerase ζ (Pol ζ) is a eukaryotic B-family DNA polymerase that specializes in translesion synthesis and is essential for normal embryogenesis. At a minimum, Pol ζ consists of a catalytic subunit Rev3 and an accessory subunit Rev7. Mammalian Rev3 contains >3,000 residues and is twice as large as the yeast homolog. To date, no vertebrate Pol ζ has been purified for biochemical characterization. Here we report purification of a series of human Rev3 deletion constructs expressed in HEK293 cells and identification of a minimally catalytically active human Pol ζ variant. With a tagged form of an active Pol ζ variant, we isolated two additional accessory subunits of human Pol ζ, PolD2 and PolD3. The purified four-subunit Pol ζ4 (Rev3–Rev7–PolD2–PolD3) is much more efficient and more processive at bypassing a 1,2-intrastrand d(GpG)-cisplatin cross-link than the two-subunit Pol ζ2 (Rev3–Rev7). We show that complete bypass of cisplatin lesions requires Pol η to insert dCTP opposite the 3′ guanine and Pol ζ4 to extend the primers. PMID:24449906

Human Pol ζ purified with accessory subunits is active in translesion DNA synthesis and complements Pol η in cisplatin bypass.

PubMed

Lee, Young-Sam; Gregory, Mark T; Yang, Wei

2014-02-25

DNA polymerase ζ (Pol ζ) is a eukaryotic B-family DNA polymerase that specializes in translesion synthesis and is essential for normal embryogenesis. At a minimum, Pol ζ consists of a catalytic subunit Rev3 and an accessory subunit Rev7. Mammalian Rev3 contains >3,000 residues and is twice as large as the yeast homolog. To date, no vertebrate Pol ζ has been purified for biochemical characterization. Here we report purification of a series of human Rev3 deletion constructs expressed in HEK293 cells and identification of a minimally catalytically active human Pol ζ variant. With a tagged form of an active Pol ζ variant, we isolated two additional accessory subunits of human Pol ζ, PolD2 and PolD3. The purified four-subunit Pol ζ4 (Rev3-Rev7-PolD2-PolD3) is much more efficient and more processive at bypassing a 1,2-intrastrand d(GpG)-cisplatin cross-link than the two-subunit Pol ζ2 (Rev3-Rev7). We show that complete bypass of cisplatin lesions requires Pol η to insert dCTP opposite the 3' guanine and Pol ζ4 to extend the primers.

[Development of oral vaccines based on recombinant proteins derived from cholera toxin].

PubMed

Sánchez, J; Solórzano, R M

1992-01-01

In this paper a new approach to create antigens through genetic engineering is discussed. In this particular case the subunits of V. cholerae toxin are used as heterologous epitope carries. In this paper the manipulation of A and B subunits is described. This manipulation allows both the insertion of epitopes to the B subunit and the use of subunit A in the construction of recombinant antigens similar to the ones derived from subunit B.

Association of eNOS polymorphisms with susceptibility to osteonecrosis of the femur head : A meta-analysis.

PubMed

Song, G G; Lee, Y H

2017-04-01

The aim of the present study was to determine whether polymorphisms of the endothelial nitric oxide synthase (eNOS) gene are associated with susceptibility to osteonecrosis of the femoral head (ONFH). We conducted a meta-analysis to assess the association between the 4b/a, G894T, and T786C polymorphisms of eNOS and the susceptibility to ONFH. A total of five studies, which included 566 cases and 833 controls, were included in the meta-analysis. Meta-analysis revealed a significant association between allele a of the 4b/a polymorphism and ONFH in all study subjects (odds ratio, OR 3.237; 95 % confidence interval, CI 2.036-5.148; P = 6.9 × 10 -7 ); stratification by ethnicity indicated an association between this allele and ONFH in Caucasians and Asians (OR 2.985; 95 % CI 1.592-5.597; P = 0.001 and OR 3.567; 95 % CI 1.793-7.095; P = 2.9 × 10 -4 , respectively). Meta-analysis stratified by ONFH type showed a significant association between allele a of the 4b/a polymorphism and idiopathic and secondary ONFH (OR 3.411; 95 % CI 2.049-5.679; P = 2.4 × 10 -6 and OR 3.163; 95 % CI 1.781-5.619, P = 8.6 × 10  -5 , respectively). However, the meta-analysis did not show any allelic association between the G894T and T786C polymorphisms and ONFH (OR 1.718; 95 % CI 0.796-3.707; P = 0.168 and OR 1.027; 95 % CI 0.191-5.517; P = 0.976, respectively). Our meta-analysis of published studies shows that the 4b/a polymorphism is associated with the development of idiopathic and secondary ONFH in Caucasians and Asians.

Association between matrix metalloproteinase 2 (MMP2) promoter polymorphisms and the susceptibility to non-Hodgkin's lymphoma in Egyptians.

PubMed

Gouda, Heba Mahmoud; Khorshied, Mervat Mamdooh; El Sissy, Maha Hamdi; Shaheen, Iman Abdel Mohsen; Mohsen, Mohsen Mokhtar Abdel

2014-08-01

Matrix metalloproteinases (MMPs) are zinc-dependent endopeptidases capable of extracellular matrix degradation. MMP2 is the key molecule that control invasion, tumor growth, and metastasis, and has been associated with poor prognosis in several tumors. Several epidemiological studies have focused on the associations between MMP2 promoter polymorphisms and cancer susceptibility; however, little is known about their role in hematological malignancies. The present study aimed to investigate the association of MMP2 -735C/T and -1306C/T promoter polymorphisms with B-NHL susceptibility and their clinicopathological characteristics. The study included 100 B-NHL patients and 100 healthy controls. Genotyping of MMP2 -735C/T and MMP2 -1306C/T was done by polymerase chain reaction restricted fragment length polymorphism (PCR-RFLP) technique. MMP2 -735C/T heteromutant genotype (CT) was detected in 23 % of patients, and the homomutant genotype (TT) was detected in 7 % of patients. The polymorphic allele, T allele, was associated with susceptibility to B-NHL (OR = 2.8:95 %CI = 1.48-5.28). For MMP2 -1306C/T, the frequencies of the polymorphic variants were 5 % for the heteromutant genotype (CT) and 3 % for the homomutant genotype (TT). The polymorphic allele, T allele, conferred almost fourfold increased risk of B-NHL (OR = 3.8, 95 %CI = 1.05-13.9), and the risk elevated to be almost eight folds when confined to diffuse large B-cell lymphoma (DLBCL) (OR = 7.9, 95 %CI = 1.67-32.27). MMP2 -735C/T polymorphic genotypes were correlated with advanced clinical stages of the disease (stages III and IV). In conclusion, the study revealed that the variant alleles of MMP2 -735C/T and MMP2 -1306C/T can be considered as molecular risk factors for B-NHL among Egyptians.

Genetic basis of human complement C8[beta] deficiency

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaufmann, T.; Rittner, C.; Schneider, P.M.

1993-06-01

The eighth component of human complement (c8) is a serum protein consisting of three chains ([alpha], [beta], and [gamma]) and encoded by three different genes, C8A, C8B, and C8G. C8A and C8B are closely linked on chromosome 1p, whereas C8G is located on chromosome 9q. In the serum the [beta] subunit is non-covalently bound to the disulfide-linked [alpha]-[gamma] subunit. Patients with C8[beta] deficiency suffer from recurrent neisserial infections such as meningitis. Exon-specific polymerase chain reaction (PCR) amplification with primer pairs from the flanking intron sequences was used to amplify all 12 C8B exons separately. No difference regarding the exon sizesmore » was observed in a C8[beta]-deficient patient compared with a normal person. Therefore, direct sequence analysis of all exon-specific PCR products from normal and C8[beta]-deficient individuals was carried out. As a cause for C8[beta] deficiency, we found a single C-T exchange in exon 9 leading to a stop codon. An allele-specific PCR system was designed to detect the normal and the deficiency allele simultaneously. Using this approach as well as PCR typing of the Taql polymorphism located in intron 11, five families with 7 C8[beta]-deficient members were investigated. The mutation was not found to be restricted to one of the two Taql RFLP alleles. The mutant allele was observed in all families investigated and can therefore be regarded as a major cause of C8[beta] deficiency in the Caucasian population. In addition, two C8[beta]-deficient patients were found to be heterozygous for the C-T exchange. The molecular basis of the alleles without this point mutation also causing deficiency has not yet been defined. 23 refs., 4 figs., 3 tabs.« less

Neurosteroid binding to the amino terminal and glutamate binding domains of ionotropic glutamate receptors.

PubMed

Cameron, Krasnodara; Bartle, Emily; Roark, Ryan; Fanelli, David; Pham, Melissa; Pollard, Beth; Borkowski, Brian; Rhoads, Sarah; Kim, Joon; Rocha, Monica; Kahlson, Martha; Kangala, Melinda; Gentile, Lisa

2012-06-01

The endogenous neurosteroids, pregnenolone sulfate (PS) and 3α-hydroxy-5β-pregnan-20-one sulfate (PREGAS), have been shown to differentially regulate the ionotropic glutamate receptor (iGluR) family of ligand-gated ion channels. Upon binding to these receptors, PREGAS decreases current flow through the channels. Upon binding to non-NMDA or NMDA receptors containing an GluN2C or GluN2D subunit, PS also decreases current flow through the channels, however, upon binding to NMDA receptors containing an GluN2A or GluN2B subunit, flow through the channels increases. To begin to understand this differential regulation, we have cloned the S1S2 and amino terminal domains (ATD) of the NMDA GluN2B and GluN2D and AMPA GluA2 subunits. Here we present results that show that PS and PREGAS bind to different sites in the ATD of the GluA2 subunit, which when combined with previous results from our lab, now identifies two binding domains for each neurosteroid. We also show both neurosteroids bind only to the ATD of the GluN2D subunit, suggesting that this binding is distinct from that of the AMPA GluA2 subunit, with both leading to iGluR inhibition. Finally, we provide evidence that both PS and PREGAS bind to the S1S2 domain of the NMDA GluN2B subunit. Neurosteroid binding to the S1S2 domain of NMDA subunits responsible for potentiation of iGluRs and to the ATD of NMDA subunits responsible for inhibition of iGluRs, provides an interesting option for therapeutic design. Copyright © 2012 Elsevier Inc. All rights reserved.

Genetic Polymorphisms in XRCC1, CD3EAP, PPP1R13L, XPB, XPC, and XPF and the Risk of Chronic Benzene Poisoning in a Chinese Occupational Population.

PubMed

Xue, Ping; Gao, Lin; Xiao, Sha; Zhang, Guopei; Xiao, Mingyang; Zhang, Qianye; Zheng, Xiao; Cai, Yuan; Jin, Cuihong; Yang, Jinghua; Wu, Shengwen; Lu, Xiaobo

2015-01-01

Individual variations in the capacity of DNA repair machinery to relieve benzene-induced DNA damage may be the key to developing chronic benzene poisoning (CBP), an increasingly prevalent occupational disease in China. ERCC1 (Excision repair cross complementation group 1) is located on chromosome 19q13.2-3 and participates in the crucial steps of Nucleotide Excision Repair (NER); moreover, we determined that one of its polymorphisms, ERCC1 rs11615, is a biomarker for CBP susceptibility in our previous report. Our aim is to further explore the deeper association between some genetic variations related to ERCC1 polymorphisms and CBP risk. Nine single nucleotide polymorphisms (SNPs) of XRCC1 (X-ray repair cross-complementing 1), CD3EAP (CD3e molecule, epsilon associated protein), PPP1R13L (protein phosphatase 1, regulatory subunit 13 like), XPB (Xeroderma pigmentosum group B), XPC (Xeroderma pigmentosum group C) and XPF (Xeroderma pigmentosum group F) were genotyped by the Snapshot and TaqMan-MGB® probe techniques, in a study involving 102 CBP patients and 204 controls. The potential interactions between these SNPs and lifestyle factors, such as smoking and drinking, were assessed using a stratified analysis. An XRCC1 allele, rs25487, was related to a higher risk of CBP (P<0.001) even after stratifying for potential confounders. Carriers of the TT genotype of XRCC1 rs1799782 who were alcohol drinkers (OR = 8.000; 95% CI: 1.316-48.645; P = 0.022), male (OR = 9.333; 95% CI: 1.593-54.672; P = 0.019), and had an exposure of ≤12 years (OR = 2.612; 95% CI: 1.048-6.510; P = 0.035) had an increased risk of CBP. However, the T allele in PPP1R13L rs1005165 (P<0.05) and the GA allele in CD3EAP rs967591 (OR = 0.162; 95% CI: 0039~0.666; P = 0.037) decreased the risk of CBP in men. The haplotype analysis of XRCC1 indicated that XRCC1 rs25487A, rs25489G and rs1799782T (OR = 15.469; 95% CI: 5.536-43.225; P<0.001) were associated with a high risk of CBP. The findings showed that the rs25487 and rs1799782 polymorphisms of XRCC1 may contribute to an individual's susceptibility to CBP and may be used as valid biomarkers. Overall, the genes on chromosome 19q13.2-3 may have a special significance in the development of CBP in occupationally exposed Chinese populations.

Genetic Polymorphisms in XRCC1, CD3EAP, PPP1R13L, XPB, XPC, and XPF and the Risk of Chronic Benzene Poisoning in a Chinese Occupational Population

PubMed Central

Xiao, Sha; Zhang, Guopei; Xiao, Mingyang; Zhang, Qianye; Zheng, Xiao; Cai, Yuan; Jin, Cuihong; Yang, Jinghua; Wu, Shengwen; Lu, Xiaobo

2015-01-01

Objectives Individual variations in the capacity of DNA repair machinery to relieve benzene-induced DNA damage may be the key to developing chronic benzene poisoning (CBP), an increasingly prevalent occupational disease in China. ERCC1 (Excision repair cross complementation group 1) is located on chromosome 19q13.2–3 and participates in the crucial steps of Nucleotide Excision Repair (NER); moreover, we determined that one of its polymorphisms, ERCC1 rs11615, is a biomarker for CBP susceptibility in our previous report. Our aim is to further explore the deeper association between some genetic variations related to ERCC1 polymorphisms and CBP risk. Methods Nine single nucleotide polymorphisms (SNPs) of XRCC1 (X-ray repair cross-complementing 1), CD3EAP (CD3e molecule, epsilon associated protein), PPP1R13L (protein phosphatase 1, regulatory subunit 13 like), XPB (Xeroderma pigmentosum group B), XPC (Xeroderma pigmentosum group C) and XPF (Xeroderma pigmentosum group F) were genotyped by the Snapshot and TaqMan-MGB® probe techniques, in a study involving 102 CBP patients and 204 controls. The potential interactions between these SNPs and lifestyle factors, such as smoking and drinking, were assessed using a stratified analysis. Results An XRCC1 allele, rs25487, was related to a higher risk of CBP (P<0.001) even after stratifying for potential confounders. Carriers of the TT genotype of XRCC1 rs1799782 who were alcohol drinkers (OR = 8.000; 95% CI: 1.316–48.645; P = 0.022), male (OR = 9.333; 95% CI: 1.593–54.672; P = 0.019), and had an exposure of ≤12 years (OR = 2.612; 95% CI: 1.048–6.510; P = 0.035) had an increased risk of CBP. However, the T allele in PPP1R13L rs1005165 (P<0.05) and the GA allele in CD3EAP rs967591 (OR = 0.162; 95% CI: 0039~0.666; P = 0.037) decreased the risk of CBP in men. The haplotype analysis of XRCC1 indicated that XRCC1 rs25487A, rs25489G and rs1799782T (OR = 15.469; 95% CI: 5.536–43.225; P<0.001) were associated with a high risk of CBP. Conclusions The findings showed that the rs25487 and rs1799782 polymorphisms of XRCC1 may contribute to an individual’s susceptibility to CBP and may be used as valid biomarkers. Overall, the genes on chromosome 19q13.2–3 may have a special significance in the development of CBP in occupationally exposed Chinese populations. PMID:26681190

A case-control study on association of proteasome subunit beta 8 (PSMB8) and transporter associated with antigen processing 1 (TAP1) polymorphisms and their transcript levels in vitiligo from Gujarat.

PubMed

Jadeja, Shahnawaz D; Mansuri, Mohmmad Shoab; Singh, Mala; Dwivedi, Mitesh; Laddha, Naresh C; Begum, Rasheedunnisa

2017-01-01

Autoimmunity has been implicated in the destruction of melanocytes from vitiligo skin. Major histocompatibility complex (MHC) class-II linked genes proteasome subunit beta 8 (PSMB8) and transporter associated with antigen processing 1 (TAP1), involved in antigen processing and presentation have been reported to be associated with several autoimmune diseases including vitiligo. To explore PSMB8 rs2071464 and TAP1 rs1135216 single nucleotide polymorphisms and to estimate the expression of PSMB8 and TAP1 in patients with vitiligo and unaffected controls from Gujarat. PSMB8 rs2071464 polymorphism was genotyped using polymerase chain reaction- restriction fragment length polymorphism (PCR-RFLP) and TAP1 rs1135216 polymorphism was genotyped by amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) in 378 patients with vitiligo and 509 controls. Transcript levels of PSMB8 and TAP1 were measured in the PBMCs of 91 patients and 96 controls by using qPCR. Protein levels of PSMB8 were also determined by Western blot analysis. The frequency of 'TT' genotype of PSMB8 polymorphism was significantly lowered in patients with generalized and active vitiligo (p = 0.019 and p = 0.005) as compared to controls suggesting its association with the activity of the disease. However, TAP1 polymorphism was not associated with vitiligo susceptibility. A significant decrease in expression of PSMB8 at both transcript level (p = 0.002) as well as protein level (p = 0.0460) was observed in vitiligo patients as compared to controls. No significant difference was observed between patients and controls for TAP1 transcripts (p = 0.553). Interestingly, individuals with the susceptible CC genotype of PSMB8 polymorphism showed significantly reduced PSMB8 transcript level as compared to that of CT and TT genotypes (p = 0.009 and p = 0.003 respectively). PSMB8 rs2071464 was associated with generalized and active vitiligo from Gujarat whereas TAP1 rs1135216 showed no association. The down-regulation of PSMB8 in patients with risk genotype 'CC' advocates the vital role of PSMB8 in the autoimmune basis of vitiligo.

Mixed effects of OATP1B1, BCRP and NTCP polymorphisms on the population pharmacokinetics of pravastatin in healthy volunteers.

PubMed

Lu, Xue-Feng; Zhou, Yang; Bi, Kai-Shun; Chen, Xiao-Hui

2016-09-01

1. Pravastatin is a 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor used for the treatment of hyperlipidaemia. This study aims to investigate the effects of genetic polymorphisms in OATP1B1, BCRP and NTCP on pravastatin population pharmacokinetics in healthy Chinese volunteers using a non-linear mixed-effect modelling (NONMEM) approach. A two-compartment model with a first-order absorption and elimination described plasma pravastatin concentrations well. 2. Genetic polymorphisms of rs4149056 (OATP1B1) and rs2306283 (OATP1B1) were found to be associated with a significant (p < 0.01) decrease in the apparent clearance from the central compartment (CL/F), while rs2296651 (NTCP) increased CL/F to a significant degree (p < 0.01). The combination of these three polymorphisms reduced the inter-individual variability of CL/F by 78.8%. 3. There was minimal effect of rs2231137 (BCRP) and rs2231142 (BCRP) on pravastatin pharmacokinetics (0.01 < p < 0.05), whereas rs11045819 (OATP1B1), rs1061018 (BCRP) and rs61745930 (NTCP) genotypes do not appear to be associated with pravastatin pharmacokinetics based on the population model (p > 0.05). 4. The current data suggest that the combination of rs4149056, rs2306283 and rs2296651 polymorphisms is an important determinant of pravastatin pharmacokinetics.

Purification of subunits of Escherichia coli DNA gyrase and reconstitution of enzymatic activity.

PubMed

Higgins, N P; Peebles, C L; Sugino, A; Cozzarelli, N R

1978-04-01

Extensively purified DNA gyrase from Escherichia coli is inhibited by nalidixic acid and by novobiocin. The enzyme is composed of two subunits, A and B, which were purified as separate components. Subunit A is the product of the gene controlling sensitivity to nalidixic acid (nalA) because: (i) the electrophoretic mobility of subunit A in the presence of sodium dodecyl sulfate is identical to that of the 105,000-dalton nalA gene product; (ii) mutants that are resistant to nalidixic acid (nalA(r)) produce a drug-resistant subunit A; and (iii) wild-type subunit A confers drug sensitivity to in vitro synthesis of varphiX174 DNA directed by nalA(r) mutants. Subunit B contains a 95,000-dalton polypeptide and is controlled by the gene specifying sensitivity to novobiocin (cou) because cou(r) mutants produce a novobiocin-resistant subunit B and novobiocin-resitant gyrase is made drug sensitive by wild-type subunit B. Subunits A and B associate, so that gyrase was also purified as a complex containing 105,000- and 95,000-dalton polypeptides. This enzyme and gyrase reconstructed from subunits have the same drug sensitivity, K(m) for ATP, and catalytic properties. The same ratio of subunits gives efficient reconstitution of the reactions intrinsic to DNA gyrase, including catalysis of supercoiling of closed duplex DNA, relaxation of supercoiled DNA in the absence of ATP, and site-specific cleavage of DNA induced by sodium dodecyl sulfate.

Alkylation of acetohydroxyacid synthase I from Escherichia coli K-12 by 3-bromopyruvate: evidence for a single active site catalyzing acetolactate and acetohydroxybutyrate synthesis.

PubMed Central

Silverman, P M; Eoyang, L

1987-01-01

Acetohydroxyacid synthase I (AHAS I) purified from Escherichia coli K-12 was irreversibly inactivated by incubation with 3-bromopyruvate. Inactivation was specific, insofar as bromoacetate and iodoacetate were much less effective than bromopyruvate. Inactivation was accompanied by incorporation of radioactivity from 3-bromo[2-14C]pyruvate into acid-insoluble material. More than 95% of the incorporated radioactivity coelectrophoresed with the 60-kilodalton IlvB subunit of the enzyme through a sodium dodecyl sulfate-polyacrylamide gel; less than 5% coelectrophoresed with the 11.2-kilodalton IlvN subunit. The stoichiometry of incorporation at nearly complete inactivation was 1 mol of 14C per mol of IlvB polypeptide. These data indicate that bromopyruvate inactivates AHAS I by alkylating an amino acid at or near a single active site located in the IlvB subunit of the enzyme. We confirmed that this alkylation inactivated both AHAS reactions normally catalyzed by AHAS I. These results provide the first direct evidence that AHAS I catalyzes both acetohydroxybutyrate and acetolactate synthesis from the same active site. Images PMID:3294793

Characterization of the patterns of polymorphism in a [open quotes]cryptic repeat[close quotes] reveals a novel type of hypervariable sequence

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jacobson, D.P.; Schmeling, P.; Sommer, S.S.

Alternating purine and pyrimidine repeats (RY(i)) are an abundant source of polymorphism. The subset with long tandem repeats of GT or AC (GT(i)) have been studied extensively, but cryptic RY(i) (i.e., no single tandem repeat predominates) have received little attention. The factor IX gene has a polymorphic cryptic RY(i) of 142-216 bp. Previously, there were four known polymorphic alleles, of the form AB, A[sub 2]B, A[sub 2]B[sub 2], and A[sub 3]B[sub 2], where A = (GT)(AC)[sub 3](AT)[sub 3](GT)(AT)[sub 4] and B = A with an additional 3' AT dinucleotide. To further characterize this locus, the authors examined more than 1,700more » additional human chromosomes and determined the sequences of the homologous sites in orangutans and chimpanzees. The novel alleles found in humans expand the repertoire of A/B alleles to A[sub 0-4]B[sub 1] and A[sub 1-3]B[sub 2]. The A[sub n]B[sub 2] series are abundant in Caucasians but are absent in blacks and Asians. Conversely, the A[sub 0]B[sub 1] allele is common in blacks but is not found in more than 1,700 Caucasian chromosomes. The data are compatible with a model in which recombination is more frequent than polymerase slippage at this locus. In orangutans, the RY(i) is present, but the sequence is markedly different. An A/B-type of pattern was discerned in which B differs from A by an additional six (AT) dinucleotides at the 3' end. In chimpanzees, the size of the RY(i) locus was greatly expanded, and the sequence showed a novel pattern of hypervariability in which there are many tandem repeats of the form (GT)[sub n](AC)[sub 0](AT)[sub p](GT)[sub q](AT)[sub s], where n, o, p, q, and s are different integers. The sequences of the factor IX intron 1 cryptic RY(i) in three primates provide perspective on the range of possible patterns of polymorphism. Analysis of the patterns suggests how the RY(i) can be conserved during evolution, while the precise sequence varies. 25 refs., 5 figs., 3 tabs.« less

Role of interleukin-15 receptor alpha polymorphisms in normal weight obese syndrome.

PubMed

Di Renzo, L; Gloria-Bottini, F; Saccucci, P; Bigioni, M; Abenavoli, L; Gasbarrini, G; De Lorenzo, A

2009-01-01

Previous published studies have identified a class of women, Normal Weight Obese women (NWO) with normal BMI and high fat content. An important role of Interleukin-15 (IL-15) has been documented in facilitating muscle proliferation and promoting fat depletion. Indeed the presence of three types of IL-15 receptor subunits in fat tissue suggests a direct effect on adipose tissue. We studied three single nucleotide polymorphisms (SNP) of IL-15R-alpha receptor gene and investigated their relationship with NWO phenotype. We considered two classes of women according to their BMI and percent fat mass (percent FAT), class 1: including 72 overweight-obese women (high BMI-high fat mass) and class 2: including 36 NWO (normal BMI, high fat mass). Three sites of Interleukin-15 receptor subunit á gene were examined, located respectively in exon4, exon5 intron-exon border and exon7. Genotyping of the identified polymorphisms was performed by restriction fragment length polymorphism. Haplotype frequency estimation was performed by using the Mendel-University of Chicago program. Odds ratio analyses were calculated by EPISTAT program. Highly significant differences were observed for exon 7- exon5 intron-exon border and exon 4-exon 7 haplotype distribution between class 1 and class 2 women. These results strongly support the hypothesis that genetic variability of the IL-15 receptor has an important role in body fat composition. Our data underscore previous findings that suggest a potential role of IL-15 cytokine in NWO syndrome.

Obstructive heart defects associated with candidate genes, maternal obesity, and folic acid supplementation.

PubMed

Tang, Xinyu; Cleves, Mario A; Nick, Todd G; Li, Ming; MacLeod, Stewart L; Erickson, Stephen W; Li, Jingyun; Shaw, Gary M; Mosley, Bridget S; Hobbs, Charlotte A

2015-06-01

Right-sided and left-sided obstructive heart defects (OHDs) are subtypes of congenital heart defects, in which the heart valves, arteries, or veins are abnormally narrow or blocked. Previous studies have suggested that the development of OHDs involved a complex interplay between genetic variants and maternal factors. Using the data from 569 OHD case families and 1,644 control families enrolled in the National Birth Defects Prevention Study (NBDPS) between 1997 and 2008, we conducted an analysis to investigate the genetic effects of 877 single nucleotide polymorphisms (SNPs) in 60 candidate genes for association with the risk of OHDs, and their interactions with maternal use of folic acid supplements, and pre-pregnancy obesity. Applying log-linear models based on the hybrid design, we identified a SNP in methylenetetrahydrofolate reductase (MTHFR) gene (C677T polymorphism) with a main genetic effect on the occurrence of OHDs. In addition, multiple SNPs in betaine-homocysteine methyltransferase (BHMT and BHMT2) were also identified to be associated with the occurrence of OHDs through significant main infant genetic effects and interaction effects with maternal use of folic acid supplements. We also identified multiple SNPs in glutamate-cysteine ligase, catalytic subunit (GCLC) and DNA (cytosine-5-)-methyltransferase 3 beta (DNMT3B) that were associated with elevated risk of OHDs among obese women. Our findings suggested that the risk of OHDs was closely related to a combined effect of variations in genes in the folate, homocysteine, or glutathione/transsulfuration pathways, maternal use of folic acid supplements and pre-pregnancy obesity. © 2015 Wiley Periodicals, Inc.

New insights into the structure-function relationships and therapeutic applications of cholera-like enterotoxins.

PubMed

Hirst, Timothy R; Fraser, Sylvia; Soriani, Marco; Aman, A Tholib; de, Haan Lolke; Hearn, Arron; Merritt, Ethan

2002-02-01

Cholera toxin and E. coli heat-labile enterotoxin are structurally homologous proteins comprised of an enzymatically active A-subunit and five B-subunits that bind with high affinity to GM1-ganglioside receptors found on the surface of mammalian cells. The B-subunits have long been thought of simply as trafficking vehicles that trigger entry and subsequent delivery of the 'toxic' A-subunit into cells. Indeed, such is the capacity of the B-subunits to enter cells, that they have been developed as generic carriers for attachment and delivery of a variety of peptides into mammalian cells. However, the B-subunits also appear to possess discrete 'signalling functions', that induce both transcription factor and cell activation. These are thought to be directly responsible for the potent immunomodulatory properties of the B-subunits, and have resulted in their use as adjuvants and as agents to suppress inflammatory immune disorders. The relationship between the signalling properties of the B-subunits and their capacity to act as trafficking vehicles has remained unclear. In an effort to understand the structural requirements for these two functions, a set of mutant B-subunits, with amino acid substitutions at position His-57, have been generated and studied. Importantly, such mutant B-subunits retain an ability to bind with high affinity to GM1 and to traffic into cells, but have entirely lost their capacity to activate immune cell populations. Thus, while binding via GM1 appears to be sufficient to trigger cellular uptake it is not sufficient to activate signal transduction. The His-57 region is therefore speculated to be actively engaged in triggering signalling events, possibly via cognate interaction with other cell surface molecules.

Interleukin 1B rs16944 G>A polymorphism was associated with a decreased risk of esophageal cancer in a Chinese population.

PubMed

Zheng, Liang; Yin, Jun; Wang, Liming; Wang, Xu; Shi, Yijun; Shao, Aizhong; Tang, Weifeng; Ding, Guowen; Liu, Chao; Chen, Suocheng; Gu, Haiyong

2013-10-01

Esophageal cancer is the sixth leading cause of cancer-associated deaths worldwide and represents a particularly aggressive type of cancer. Genetic polymorphisms may partly explain individual differences in esophageal cancer susceptibility. We conducted a hospital-based case-control study to evaluate the genetic effects of functional single nucleotide polymorphisms (SNPs) in the interleukin 1 (IL1A and IL1B), IL1f7, IL3 and IL7Ra genes on the development of esophageal cancer. A total of 380 esophageal squamous cell carcinoma (ESCC) cases and 380 controls were recruited for this study. The genotypes were determined using a custom-by-design 48-Plex SNPscan™ Kit. When the IL1B rs16944 GG homozygote genotype was used as the reference group, the GA genotype was associated with a significantly decreased risk of ESCC (GA vs. GG: adjusted OR=0.69, 95% CI=0.49-0.99, p=0.041). However, there were no significant associations between the other five SNPs and ESCC risk. Stratified analyses indicated no significantly different risks of ESCC associated with the IL1B rs16944 G>A polymorphism according to sex, age, smoking status or alcohol consumption. IL3 rs2073506 G>A polymorphism was associated with an increased risk for ESCC higher tumor, nodal, and metastatic (TNM) stages. These findings indicated that the functional IL1B rs16944 G>A polymorphism might contribute to ESCC susceptibility. IL3 rs2073506 G>A polymorphism was associated with an increased risk for ESCC higher TNM stages. However, the results were based on a limited sample size and larger well-designed studies are warranted to confirm these initial findings. Copyright © 2013 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

IL-10 and IL-12B gene polymorphisms in a multiethnic Malaysian population.

PubMed

Sam, S S; Teoh, B T; AbuBakar, S

2015-04-13

Inheritance of polymorphisms in the interleukin (IL)-10 promoter and IL-12B genes, which influence cytokine production and activities, may define the balance in T helper response in infection and autoimmune diseases. In the present study, we investigated the distribution of the IL-10 promoter and IL-12B gene polymorphisms in a multiethnic Malaysian population. Overall, our findings suggest that the IL-12B and IL-10 -592 genotypes were distributed homogenously across all major ethnic groups, including Malays, Chinese, and Indians, except for polymorphisms at IL-10 -1082. At this gene locus, the ethnic Chinese showed a significantly lower allele frequency of -1082G (2.1%) compared to the Malay (12.2%) and Indian (15.3%) populations. Results for the IL-12B and IL-10 gene polymorphisms were consistent with those reported for the Asian population, but markedly different from those of the African and Caucasian populations. Our findings suggest that there are specific genetic variations between different ethnic groups, which should be examined in all gene population-based association studies.

Crystal structure of a protein phosphatase 2A heterotrimeric holoenzyme.

PubMed

Cho, Uhn Soo; Xu, Wenqing

2007-01-04

Protein phosphatase 2A (PP2A) is a principal Ser/Thr phosphatase, the deregulation of which is associated with multiple human cancers, Alzheimer's disease and increased susceptibility to pathogen infections. How PP2A is structurally organized and functionally regulated remains unclear. Here we report the crystal structure of an AB'C heterotrimeric PP2A holoenzyme. The structure reveals that the HEAT repeats of the scaffold A subunit form a horseshoe-shaped fold, holding the catalytic C and regulatory B' subunits together on the same side. The regulatory B' subunit forms pseudo-HEAT repeats and interacts with the C subunit near the active site, thereby defining substrate specificity. The methylated carboxy-terminal tail of the C subunit interacts with a highly negatively charged region at the interface between A and B' subunits, suggesting that the C-terminal carboxyl methylation of the C subunit promotes B' subunit recruitment by neutralizing charge repulsion. Together, our structural results establish a crucial foundation for understanding PP2A assembly, substrate recruitment and regulation.

Conformational coupling between the active site and residues within the K(C)-channel of the Vibrio cholerae cbb3-type (C-family) oxygen reductase.

PubMed

Ahn, Young O; Mahinthichaichan, Paween; Lee, Hyun Ju; Ouyang, Hanlin; Kaluka, Daniel; Yeh, Syun-Ru; Arjona, Davinia; Rousseau, Denis L; Tajkhorshid, Emad; Adelroth, Pia; Gennis, Robert B

2014-10-21

The respiratory chains of nearly all aerobic organisms are terminated by proton-pumping heme-copper oxygen reductases (HCOs). Previous studies have established that C-family HCOs contain a single channel for uptake from the bacterial cytoplasm of all chemical and pumped protons, and that the entrance of the K(C)-channel is a conserved glutamate in subunit III. However, the majority of the K(C)-channel is within subunit I, and the pathway from this conserved glutamate to subunit I is not evident. In the present study, molecular dynamics simulations were used to characterize a chain of water molecules leading from the cytoplasmic solution, passing the conserved glutamate in subunit III and extending into subunit I. Formation of the water chain, which controls the delivery of protons to the K(C)-channel, was found to depend on the conformation of Y241(Vc), located in subunit I at the interface with subunit III. Mutations of Y241(Vc) (to A/F/H/S) in the Vibrio cholerae cbb3 eliminate catalytic activity, but also cause perturbations that propagate over a 28-Å distance to the active site heme b3. The data suggest a linkage between residues lining the K(C)-channel and the active site of the enzyme, possibly mediated by transmembrane helix α7, which contains both Y241(Vc) and the active site cross-linked Y255(Vc), as well as two CuB histidine ligands. Other mutations of residues within or near helix α7 also perturb the active site, indicating that this helix is involved in modulation of the active site of the enzyme.

Lysosome-mediated Cell Death and Autophagy-Dependent Multidrug Resistance in Breast Cancer

DTIC Science & Technology

2008-10-01

gene links mitochondria and cell death, the data suggests that Bcl2 may be involved in autophagic cell death and AD-MDR. GeneGo analysis also...GSK3 beta GSK3 beta E2A p53 p21 p21 E2F1 PPAR -gamma JNK1(MA PK8) JNK1(M APK8) ESR1 (nuclear) RARalpha Androgen receptor Androge n receptor p53...RelA (p65 NF-kB subunit) Erk (MAPK1/3 ) Erk (MAPK1/ 3) PPAR - gamma SOX9 Bcl-2 Bcl-2 RARalpha SP1 EGFR EGFR RelA (p65 NF- kB subunit) RARalpha RelA

Genetic and Non-Genetic Covariates of Pain Severity in Patients with Adenocarcinoma of the Pancreas: Assessing the Influence of Cytokine Genes

PubMed Central

Reyes-Gibby, Cielito C.; Shete, Sanjay; Yennurajalingam, Sriram; Frazier, Marsha; Bruera, Eduardo; Kurzrock, Razelle; Crane, Christopher H.; Abbruzzese, James; Evans, Douglas; Spitz, Margaret R.

2009-01-01

We previously demonstrated that select cytokine gene polymorphisms in interleukin (IL)-8 are a significant predictor for pain and analgesia in patients with lung cancer. This study explores the role of thirteen potentially functional polymorphisms in cytokine genes including IL-1β, IL-6, IL-8, IL-10, IL-18, tumor necrosis factor (TNF-α), and nuclear factor kappa-B subunit 1 (NFkappaB1) in pain severity in patients with pancreatic cancer. We evaluated a series opatients with histologically-confirmed adenocarcinoma of the pancreas (n=484) who had completed a self-administered survey of pain prior to initiating any cancer treatment. DNA (n=156) available for a subset of white patients was assayed and assessed for association with pain severity. Results showed that 26% (128/484) reported experiencing severe pain (score of > 7 on a 0–10 scale). Severe pain varied by stage of disease (odds ratio [OR] Stage II=4.02, 95% confidence interval (CI)=1.07, 15.07; Stage III=5.02, 95% CI=1.28, 19.61; Stage IV=6.90, 95% CI=1.96, 24.29), ethnicity (OR non-Hispanic blacks=3.67; 95% CI=1.44, 9.38), reports of depressed mood (OR=1.94; 95% CI=1.09, 3.43), and female sex (OR=1.78; 95% CI=1.04, 3.05). Controlling for these covariates, IL8-251T/A (OR=2.43, 95% CI=1.3, 4.7, P<0.009) significantly predicted severe pain in a subset of white patients. When we adjusted for reported analgesic use, we found that IL8-251T/A persisted as a predictor for severe pain, with carriers of TT and AT genotypes having more than a threefold risk (OR=3.23, 95% CI=1.4, 4.7) for severe pain relative to the AA genotypes. We provide preliminary evidence of the role of IL-8 in the severity of pain in pancreatic cancer patients. Additional studies are needed in larger cohorts of patients. PMID:19692203

Reductions in the Cardiac Transient Outward K+ Current Ito Caused by Chronic β-Adrenergic Receptor Stimulation Are Partly Rescued by Inhibition of Nuclear Factor κB.

PubMed

Panama, Brian K; Korogyi, Adam S; Aschar-Sobbi, Roozbeh; Oh, Yena; Gray, Charles B B; Gang, Hongying; Brown, Joan Heller; Kirshenbaum, Lorrie A; Backx, Peter H

2016-02-19

The fast transient outward potassium current (Ito,f) plays a critical role in the electrical and contractile properties of the myocardium. Ito,f channels are formed by the co-assembly of the pore-forming α-subunits, Kv4.2 and Kv4.3, together with the accessory β-subunit KChIP2. Reductions of Ito,f are common in the diseased heart, which is also associated with enhanced stimulation of β-adrenergic receptors (β-ARs). We used cultured neonatal rat ventricular myocytes to examine how chronic β-AR stimulation decreases Ito,f. To determine which downstream pathways mediate these Ito,f changes, adenoviral infections were used to inhibit CaMKIIδc, CaMKIIδb, calcineurin, or nuclear factor κB (NF-κB). We observed that chronic β-AR stimulation with isoproterenol (ISO) for 48 h reduced Ito,f along with mRNA expression of all three of its subunits (Kv4.2, Kv4.3, and KChIP2). Inhibiting either CaMKIIδc nor CaMKIIδb did not prevent the ISO-mediated Ito,f reductions, even though CaMKIIδc and CaMKIIδb clearly regulated Ito,f and the mRNA expression of its subunits. Likewise, calcineurin inhibition did not prevent the Ito,f reductions induced by β-AR stimulation despite strongly modulating Ito,f and subunit mRNA expression. In contrast, NF-κB inhibition partly rescued the ISO-mediated Ito,f reductions in association with restoration of KChIP2 mRNA expression. Consistent with these observations, KChIP2 promoter activity was reduced by p65 as well as β-AR stimulation. In conclusion, NF-κB, and not CaMKIIδ or calcineurin, partly mediates the Ito,f reductions induced by chronic β-AR stimulation. Both mRNA and KChIP2 promoter data suggest that the ISO-induced Ito,f reductions are, in part, mediated through reduced KChIP2 transcription caused by NF-κB activation. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Novel DNA variations to characterize low molecular weight glutenin Glu-D3 genes and develop STS markers in common wheat.

PubMed

Zhao, X L; Xia, X C; He, Z H; Lei, Z S; Appels, R; Yang, Y; Sun, Q X; Ma, W

2007-02-01

Low-molecular-weight glutenin subunits (LMW-GS) play an important role in bread and noodle processing quality by influencing the viscoelasticity and extensibility of dough. The objectives of this study were to characterize Glu-D3 subunit coding genes and to develop molecular markers for identifying Glu-D3 gene haplotypes. Gene specific primer sets were designed to amplify eight wheat cultivars containing Glu-D3a, b, c, d and e alleles, defined traditionally by protein electrophoretic mobility. Three novel Glu-D3 DNA sequences, designated as GluD3-4, GluD3-5 and GluD3-6, were amplified from the eight wheat cultivars. GluD3-4 showed three allelic variants or haplotypes at the DNA level in the eight cultivars, which were designated as GluD3-41, GluD3-42 and GluD3-43. Compared with GluD3-42, a single nucleotide polymorphism (SNP) was detected for GluD3-43 in the coding region, resulting in a pseudo-gene with a nonsense mutation at the 119th position of deduced peptide, and a 3-bp insertion was found in the coding region of GluD3-41, leading to a glutamine insertion at the 249th position of its deduced protein. The coding regions for GluD3-5 and GluD3-6 showed no allelic variation in the eight cultivars tested, indicating that they were relatively conservative in common wheat. Based on the 12 allelic variants of three Glu-D3 genes identified in this study and three detected previously, seven STS markers were established to amplify the corresponding gene sequences in wheat cultivars containing five Glu-D3 alleles (a, b, c, d and e). The seven primer sets M2F12/M2R12, M2F2/M2R2, M2F3/M2R3, M3F1/M3R1, M3F2/M3R2, M4F1/M4R1 and M4F3/M4R3 were specific to the allelic variants GluD3-21/22, GluD3-22, GluD3-23, GluD3-31, GluD3-32, GluD3-41 and GluD3-43, respectively, which were validated by amplifying 20 Chinese wheat cultivars containing alleles a, b, c and f based on protein electrophoretic mobility. These markers will be useful to identify the Glu-D3 gene haplotypes in wheat breeding programs.

The 11S Proteasome Subunit PSME3 Is a Positive Feedforward Regulator of NF-κB and Important for Host Defense against Bacterial Pathogens.

PubMed

Sun, Jinxia; Luan, Yi; Xiang, Dong; Tan, Xiao; Chen, Hui; Deng, Qi; Zhang, Jiaojiao; Chen, Minghui; Huang, Hongjun; Wang, Weichao; Niu, Tingting; Li, Wenjie; Peng, Hu; Li, Shuangxi; Li, Lei; Tang, Wenwen; Li, Xiaotao; Wu, Dianqing; Wang, Ping

2016-02-02

The NF-κB pathway plays important roles in immune responses. Although its regulation has been extensively studied, here, we report an unknown feedforward mechanism for the regulation of this pathway by Toll-like receptor (TLR) ligands in macrophages. During bacterial infections, TLR ligands upregulate the expression of the 11S proteasome subunit PSME3 via NF-κB-mediated transcription in macrophages. PSME3, in turn, enhances the transcriptional activity of NF-κB by directly binding to and destabilizing KLF2, a negative regulator of NF-κB transcriptional activity. Consistent with this positive role of PSME3 in NF-κB regulation and importance of the NF-κB pathway in host defense against bacterial infections, the lack of PSME3 in hematopoietic cells renders the hosts more susceptible to bacterial infections, accompanied by increased bacterial burdens in host tissues. Thus, this study identifies a substrate for PSME3 and elucidates a proteolysis-dependent, but ubiquitin-independent, mechanism for NF-κB regulation that is important for host defense and innate immunity. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Expression of accessory colonization factor subunit A (ACFA) of Vibrio cholerae and ACFA fused to cholera toxin B subunit in transgenic tomato (Solanum lycopersicum).

PubMed

Sharma, Manoj Kumar; Jani, Dewal; Thungapathra, M; Gautam, J K; Meena, L S; Singh, Yogendra; Ghosh, Amit; Tyagi, Akhilesh Kumar; Sharma, Arun Kumar

2008-05-20

In earlier study from our group, cholera toxin B subunit had been expressed in tomato for developing a plant-based vaccine against cholera. In the present investigation, gene for accessory colonization factor (acf) subunit A, earlier reported to be essential for efficient colonization in the intestine, has been expressed in Escherichia coli as well as tomato plants. Gene encoding for a chimeric protein having a fusion of cholera toxin B subunit and accessory colonization factor A was also expressed in tomato to generate more potent combinatorial antigen. CaMV35S promoter with a duplicated enhancer sequence was used for expression of these genes in tomato. Integration of transgenes into tomato genome was confirmed by PCR and Southern hybridization. Expression of the genes was confirmed at transcript and protein levels. Accessory colonization factor A and cholera toxin B subunit fused to this protein accumulated up to 0.25% and 0.08% of total soluble protein, respectively, in the fruits of transgenic plants. Whereas protein purified from E. coli, in combination with cholera toxin B subunit can be used for development of conventional subunit vaccine, tomato fruits expressing these proteins can be used together with tomato plants expressing cholera toxin B subunit for development of oral vaccine against cholera.

Triclosan-Evoked Neurotoxicity Involves NMDAR Subunits with the Specific Role of GluN2A in Caspase-3-Dependent Apoptosis.

PubMed

Szychowski, Konrad A; Wnuk, Agnieszka; Rzemieniec, Joanna; Kajta, Małgorzata; Leszczyńska, Teresa; Wójtowicz, Anna K

2018-04-19

Triclosan (TCS) is an antimicrobial agent that is used extensively in personal care and in sanitising products. A number of studies have shown the presence of TCS in different human tissues such as blood, adipose tissue, the liver, brain as well as in breast milk and urine. N-Methyl-D-aspartate receptors (NMDARs) are glutamate-gated ion channels that are widely expressed in the central nervous system and which play key roles in excitatory synaptic transmission. There is, however, no data on the involvement of NMDAR subunits in the apoptotic and neurotoxic effects of TCS. Our experiments are the first to show that TCS used at environmentally relevant concentrations evoked NMDA-dependent effects in neocortical neurons in primary cultures, as MK-801, an uncompetitive NMDA receptor antagonist, reduced the levels of TCS-induced ROS production as well as caspase-3 activity and LDH release. TCS caused a decrease in protein expression of all the studied NMDA receptor subunits (GluN1, GluN2A, GluN2B) that were measured at 3, 6 and 24 h post-treatment. However, at 48 h of the experiment, the level of the GluN1 subunit returned to the control level, and the levels of the other subunits showed a tendency to increase. In TCS-treated neocortical cells, protein profiles of NMDAR subunits measured up to 24 h were similar to mRNA expression of GluN1 and GluN2A, but not to GluN2B mRNA. In this study, cells transiently transfected with GluN1, GluN2A or GluN2B siRNA exhibited reduced levels of LDH release, which suggests the involvement of all of the studied NMDAR subunits in the neurotoxic action of TCS. According to our data, GluN1 and GluN2A were mainly responsible for neuronal cell death as evidenced by neutral red uptake, whereas GluN2A was involved in TCS-induced caspase-3-dependent apoptosis. We suggest that TCS-evoked apoptosis and neurotoxicity could be related to transient degradation of NMDAR subunits in mouse neurons. Furthermore, recycling of NMDAR subunits in response to TCS is possible. Because transfections with specific siRNA did not completely abolish the effects of TCS as compared to cells transfected with negative siRNA in this study, other NMDAR-independent mechanisms of TCS action are also possible.

PP2A regulates autophagy in two alternative ways in Drosophila.

PubMed

Bánréti, Ágnes; Lukácsovich, Tamás; Csikós, György; Erdélyi, Miklós; Sass, Miklós

2012-04-01

Protein phosphatase 2A (PP2A) holoenzyme is a heterotrimeric complex, consisting of A, B and C subunits. The catalytic subunit PP2A-C (microtubule star/mts) binds to the C-terminal part of the scaffold protein PP2A-A (PP2A-29B). In Drosophila, there are three different forms of B subunits (widerborst/wdb, twins/tws and PP2A-B'), which determine the subcellular localization and substrate specificity of the holoenzyme. Previous studies demonstrated that PP2A is involved in the control of TOR-dependent autophagy both in yeast and mammals. Furthermore, in Drosophila, wdb genetically interacts with the PtdIns3K/PTEN/Akt signaling cascade, which is a main upstream regulatory system of dTOR. Here we demonstrate that in Drosophila, two different PP2A complexes (containing B' or wdb subunit) play essential roles in the regulation of starvation-induced autophagy. The PP2A-A/wdb/C complex acts upstream of dTOR, whereas the PP2A-A/B'/C complex functions as a target of dTOR and may regulate the elongation of autophagosomes and their subsequent fusion with lysosomes. We also identified three Drosophila Atg orthologs (Atg14, Atg17 and Atg101), which represent potential targets of the PP2A-A/B'/C complex during autophagy.

SPARCHS: Symbiotic, Polymorphic, Automatic, Resilient, Clean-Slate, Host Security

DTIC Science & Technology

2016-03-01

SPARCHS: SYMBIOTIC , POLYMORPHIC, AUTOMATIC, RESILIENT, CLEAN-SLATE, HOST SECURITY COLUMBIA UNIVERSITY MARCH 2016 FINAL... SYMBIOTIC , POLYMORPHIC, AUTOTOMIC, RESILIENT, CLEAN-SLATE, HOST SECURITY 5a. CONTRACT NUMBER N/A 5b. GRANT NUMBER FA8750-10-2-0253 5c. PROGRAM...17 4.2.3 SYMBIOTIC EMBEDDED MACHINES

Phosphorylation of Wheat Germ Initiation Factors and Ribosomal Proteins 1

PubMed Central

Browning, Karen S.; Yan, Tyan Fuh J.; Lauer, Stephen J.; Aquino, Lu Ann; Tao, Mariano; Ravel, Joanne M.

1985-01-01

The ability of the wheat germ initiation factors and ribosomes to serve as substrates for a wheat germ protein kinase (Yan and Tao 1982 J Biol Chem 257: 7037-7043) has been investigated. The wheat germ kinase catalyzes the phosphorylation of the 42,000 dalton subunit of eukaryotic initiation factor (eIF)-2 and the 107,000 dalton subunit of eIF-3. Other initiation factors, eIF-4B and eIF-4A, and elongation factors, EF-1 and EF-2, are not phosphorylated by the kinase. Quantitative analysis indicates that the kinase catalyzes the incorporation of about 0.5 to 0.6 mole of phosphate per mole of the 42,000 dalton subunit of eIF-2 and about 6 moles of phosphate per mole of the 107,000 dalton subunit of eIF-3. Three proteins (Mr = 38,000, 14,800, and 12,600) of the 60S ribosomal subunit are phosphorylated by the kinase, but none of the 40S ribosomal proteins are substrates of the kinase. No effects of phosphorylation on the activities of eIF-2, eIF-3, or 60S ribosomal subunits could be demonstrated in vitro. Images Fig. 1 Fig. 3 Fig. 4 PMID:16664060

Toll-Like Receptor 2 Mediates Cellular Activation by the B Subunits of Type II Heat-Labile Enterotoxins

PubMed Central

Hajishengallis, George; Tapping, Richard I.; Martin, Michael H.; Nawar, Hesham; Lyle, Elizabeth A.; Russell, Michael W.; Connell, Terry D.

2005-01-01

The type II heat-labile enterotoxins (LT-IIa and LT-IIb) of Escherichia coli have an AB5 subunit structure similar to that of cholera toxin (CT) and other type I enterotoxins, despite significant differences in the amino acid sequences of their B subunits and different ganglioside receptor specificities. LT-II holotoxins and their nontoxic B subunits display unique properties as immunological adjuvants distinct from those of CT and its B subunits. In contrast to type II holotoxins, the corresponding pentameric B subunits, LT-IIaB and LT-IIbB, stimulated cytokine release in both human and mouse cells dependent upon Toll-like receptor 2 (TLR2). Induction of interleukin-1β (IL-1β), IL-6, IL-8, or tumor necrosis factor alpha in human THP-1 cells by LT-IIaB or LT-IIbB was inhibited by anti-TLR2 but not by anti-TLR4 antibody. Furthermore, transient expression of TLR1 and TLR2 in human embryonic kidney 293 cells resulted in activation of a nuclear factor-κB-dependent luciferase gene in response to LT-IIaB or LT-IIbB. Moreover, peritoneal macrophages from TLR2-deficient mice failed to respond to LT-IIaB or LT-IIbB, in contrast to wild-type or TLR4-deficient cells. These results demonstrate that besides their established binding to gangliosides, the B subunits of type II enterotoxins also interact with TLR2. Although a ganglioside-nonbinding mutant (T34I) of LT-IIaB effectively induced cytokine release, a phenotypically similar point mutation (T13I) in LT-IIbB abrogated cytokine induction, suggesting a variable requirement for gangliosides as coreceptors in TLR2 agonist activity. TLR2-dependent activation of mononuclear cells by type II enterotoxin B subunits appears to be a novel mechanism whereby these molecules may exert their immunomodulatory and adjuvant activities. PMID:15731031

Inherent conformational flexibility of F1-ATPase α-subunit.

PubMed

Hahn-Herrera, Otto; Salcedo, Guillermo; Barril, Xavier; García-Hernández, Enrique

2016-09-01

The core of F1-ATPase consists of three catalytic (β) and three noncatalytic (α) subunits, forming a hexameric ring in alternating positions. A wealth of experimental and theoretical data has provided a detailed picture of the complex role played by catalytic subunits. Although major conformational changes have only been seen in β-subunits, it is clear that α-subunits have to respond to these changes in order to be able to transmit information during the rotary mechanism. However, the conformational behavior of α-subunits has not been explored in detail. Here, we have combined unbiased molecular dynamics (MD) simulations and calorimetrically measured thermodynamic signatures to investigate the conformational flexibility of isolated α-subunits, as a step toward deepening our understanding of its function inside the α3β3 ring. The simulations indicate that the open-to-closed conformational transition of the α-subunit is essentially barrierless, which is ideal to accompany and transmit the movement of the catalytic subunits. Calorimetric measurements of the recombinant α-subunit from Geobacillus kaustophilus indicate that the isolated subunit undergoes no significant conformational changes upon nucleotide binding. Simulations confirm that the nucleotide-free and nucleotide-bound subunits show average conformations similar to that observed in the F1 crystal structure, but they reveal an increased conformational flexibility of the isolated α-subunit upon MgATP binding, which might explain the evolutionary conserved capacity of α-subunits to recognize nucleotides with considerable strength. Furthermore, we elucidate the different dependencies that α- and β-subunits show on Mg(II) for recognizing ATP. Copyright © 2016 Elsevier B.V. All rights reserved.

Influence of uridine diphosphate glucuronosyltransferase 2B7 -161C>T polymorphism on the concentration of valproic acid in pediatric epilepsy patients.

PubMed

Inoue, Kazuyuki; Suzuki, Eri; Yazawa, Rei; Yamamoto, Yoshiaki; Takahashi, Toshiki; Takahashi, Yukitoshi; Imai, Katsumi; Koyama, Seiichi; Inoue, Yushi; Tsuji, Daiki; Hayashi, Hideki; Itoh, Kunihiko

2014-06-01

Valproic acid (VPA) is widely used to treat various types of epilepsy. Interindividual variability in VPA pharmacokinetics may arise from genetic polymorphisms of VPA-metabolizing enzymes. This study aimed to examine the relationships between plasma VPA concentrations and the -161C>T single nucleotide polymorphism in uridine diphosphate glucuronosyltransferase (UGT) 2B7 genes in pediatric epilepsy patients. This study included 78 pediatric epilepsy patients carrying the cytochrome P450 (CYP) 2C9*1/*1 genotype and who were not treated with the enzyme inducers (phenytoin, phenobarbital, and carbamazepine), lamotrigine, and/or topiramate. CYP2C9*3 and UGT2B7 -161C>T polymorphisms were identified using methods based on polymerase chain reaction-restriction fragment length polymorphism. Blood samples were drawn from each patient under steady-state conditions, and plasma VPA concentrations were measured. Significant differences in adjusted plasma VPA concentrations were observed between carriers of CC, CT, and TT genotypes in the UGT2B7 -161C>T polymorphism (P = 0.039). Patients with the CC genotype had lower adjusted plasma VPA concentrations than those with CT or TT genotype (P = 0.028). These data suggest that the UGT2B7 -161C>T polymorphism in pediatric epilepsy patients carrying the CYP2C9*1/*1 genotype affects VPA concentration.

Heteromultimerization modulates P2X receptor functions through participating extracellular and C-terminal subdomains.

PubMed

Koshimizu, Taka-aki; Ueno, Susumu; Tanoue, Akito; Yanagihara, Nobuyuki; Stojilkovic, Stanko S; Tsujimoto, Gozoh

2002-12-06

P2X purinergic receptors (P2XRs) differ among themselves with respect to their ligand preferences and channel kinetics during activation, desensitization, and recovery. However, the contributions of distinct receptor subdomains to the subtype-specific behavior have been incompletely characterized. Here we show that homomeric receptors having the extracellular domain of the P2X(3) subunit in the P2X(2a)-based backbone (P2X(2a)/X(3)ex) mimicked two intrinsic functions of P2X(3)R, sensitivity to alphabeta-methylene ATP and ecto-ATPase-dependent recovery from endogenous desensitization; these two functions were localized to the N- and C-terminal halves of the P2X(3) extracellular loop, respectively. The chimeric P2X(2a)R/X(3)ex receptors also desensitized with accelerated rates compared with native P2X(2a)R, and the introduction of P2X(2) C-terminal splicing into the chimeric subunit (P2X(2b)/X(3)ex) further increased the rate of desensitization. Physical and functional heteromerization of native P2X(2a) and P2X(2b) subunits was also demonstrated. In heteromeric receptors, the ectodomain of P2X(3) was a structural determinant for ligand selectivity and recovery from desensitization, and the C terminus of P2X(2) was an important factor for the desensitization rate. Furthermore, [gamma-(32)P]8-azido ATP, a photoreactive agonist, was effectively cross-linked to P2X(3) subunit in homomeric receptors but not in heteromeric P2X(2) + P2X(3)Rs. These results indicate that heteromeric receptors formed by distinct P2XR subunits develop new functions resulting from integrative effects of the participating extracellular and C-terminal subdomains.

Ferulic Acid Attenuates the Injury-Induced Decrease of Protein Phosphatase 2A Subunit B in Ischemic Brain Injury

PubMed Central

Koh, Phil-Ok

2013-01-01

Background Ferulic acid provides a neuroprotective effect during cerebral ischemia through its anti-oxidant function. Protein phosphatase 2A (PP2A) is a serine and threonine phosphatase that contributes broadly to normal brain function. This study investigated whether ferulic acid regulates PP2A subunit B in a middle cerebral artery occlusion (MCAO) animal model and glutamate toxicity-induced neuronal cell death. Methodology/Principal Findings MCAO was surgically induced to yield permanent cerebral ischemic injury in rats. The rats were treated with either vehicle or ferulic acid (100 mg/kg, i.v.) immediately after MCAO, and cerebral cortex tissues were collected 24 h after MCAO. A proteomics approach, RT-PCR, and Western blot analyses performed to identification of PP2A subunit B expression levels. Ferulic acid significantly reduced the MCAO-induced infarct volume of the cerebral cortex. A proteomics approach elucidated the reduction of PP2A subunit B in MCAO-induced animals, and ferulic acid treatment prevented the injury-induced reduction in PP2A subunit B levels. RT-PCR and Western blot analyses also showed that ferulic acid treatment attenuates the injury-induced decrease in PP2A subunit B levels. Moreover, the number of PP2A subunit B-positive cells was reduced in MCAO-induced animals, and ferulic acid prevented these decreases. In cultured neuronal cells, ferulic acid treatment protected cells against glutamate toxicity and prevented the glutamate-induced decrease in PP2A subunit B. Conclusions/Significance These results suggest that the maintenance of PP2A subunit B by ferulic acid in ischemic brain injury plays an important role for the neuroprotective function of ferulic acid. PMID:23349830

Suppressor mutations identify amino acids in PAA-1/PR65 that facilitate regulatory RSA-1/B″ subunit targeting of PP2A to centrosomes in C. elegans

PubMed Central

Lange, Karen I.; Heinrichs, Jeffrey; Cheung, Karen; Srayko, Martin

2013-01-01

Summary Protein phosphorylation and dephosphorylation is a key mechanism for the spatial and temporal regulation of many essential developmental processes and is especially prominent during mitosis. The multi-subunit protein phosphatase 2A (PP2A) enzyme plays an important, yet poorly characterized role in dephosphorylating proteins during mitosis. PP2As are heterotrimeric complexes comprising a catalytic, structural, and regulatory subunit. Regulatory subunits are mutually exclusive and determine subcellular localization and substrate specificity of PP2A. At least 3 different classes of regulatory subunits exist (termed B, B′, B″) but there is no obvious similarity in primary sequence between these classes. Therefore, it is not known how these diverse regulatory subunits interact with the same holoenzyme to facilitate specific PP2A functions in vivo. The B″ family of regulatory subunits is the least understood because these proteins lack conserved structural domains. RSA-1 (regulator of spindle assembly) is a regulatory B″ subunit required for mitotic spindle assembly in Caenorhabditis elegans. In order to address how B″ subunits interact with the PP2A core enzyme, we focused on a conditional allele, rsa-1(or598ts), and determined that this mutation specifically disrupts the protein interaction between RSA-1 and the PP2A structural subunit, PAA-1. Through genetic screening, we identified a putative interface on the PAA-1 structural subunit that interacts with a defined region of RSA-1/B″. In the context of previously published results, these data propose a mechanism of how different PP2A B-regulatory subunit families can bind the same holoenzyme in a mutually exclusive manner, to perform specific tasks in vivo. PMID:23336080

IκB kinaseα/β control biliary homeostasis and hepatocarcinogenesis in mice by phosphorylating the cell-death mediator receptor-interacting protein kinase 1.

PubMed

Koppe, Christiane; Verheugd, Patricia; Gautheron, Jérémie; Reisinger, Florian; Kreggenwinkel, Karina; Roderburg, Christoph; Quagliata, Luca; Terracciano, Luigi; Gassler, Nikolaus; Tolba, René H; Boege, Yannick; Weber, Achim; Karin, Michael; Luedde, Mark; Neumann, Ulf P; Weiskirchen, Ralf; Tacke, Frank; Vucur, Mihael; Trautwein, Christian; Lüscher, Bernhard; Preisinger, Christian; Heikenwalder, Mathias; Luedde, Tom

2016-10-01

The IκB-Kinase (IKK) complex-consisting of the catalytic subunits, IKKα and IKKβ, as well as the regulatory subunit, NEMO-mediates activation of the nuclear factor κB (NF-κB) pathway, but previous studies suggested the existence of NF-κB-independent functions of IKK subunits with potential impact on liver physiology and disease. Programmed cell death is a crucial factor in the progression of liver diseases, and receptor-interacting kinases (RIPKs) exerts strategic control over multiple pathways involved in regulating novel programmed cell-death pathways and inflammation. We hypothesized that RIPKs might be unrecognized targets of the catalytic IKK-complex subunits, thereby regulating hepatocarcinogenesis and cholestasis. In this present study, mice with specific genetic inhibition of catalytic IKK activity in liver parenchymal cells (LPCs; IKKα/β(LPC-KO) ) were intercrossed with RIPK1(LPC-KO) or RIPK3(-/-) mice to examine whether RIPK1 or RIPK3 might be downstream targets of IKKs. Moreover, we performed in vivo phospho-proteome analyses and in vitro kinase assays, mass spectrometry, and mutagenesis experiments. These analyses revealed that IKKα and IKKβ-in addition to their known function in NF-κB activation-directly phosphorylate RIPK1 at distinct regions of the protein, thereby regulating cell viability. Loss of this IKKα/β-dependent RIPK1 phosphorylation in LPCs inhibits compensatory proliferation of hepatocytes and intrahepatic biliary cells, thus impeding HCC development, but promoting biliary cell paucity and lethal cholestasis. IKK-complex subunits transmit a previously unrecognized signal through RIPK1, which is fundamental for the long-term consequences of chronic hepatic inflammation and might have potential implications for future pharmacological strategies against cholestatic liver disease and cancer. (Hepatology 2016;64:1217-1231). © 2016 by the American Association for the Study of Liver Diseases.

Association of Polymorphisms of Cytochrome P450 2D6 With Blood Hydroxychloroquine Levels in Patients With Systemic Lupus Erythematosus.

PubMed

Lee, Ji Yeon; Vinayagamoorthy, Nadimuthu; Han, Kyungdo; Kwok, Seung Ki; Ju, Ji Hyeon; Park, Kyung Su; Jung, Seung-Hyun; Park, Sung-Won; Chung, Yeun-Jun; Park, Sung-Hwan

2016-01-01

To evaluate associations of genetic polymorphisms in cytochrome P450 (CYP) isoforms 2D6, 3A5, and 3A4 with blood concentrations of hydroxychloroquine (HCQ) and its metabolite, N-desethyl HCQ (DHCQ), in patients with systemic lupus erythematosus (SLE). SLE patients taking HCQ for >3 months were recruited and were genotyped for 4 single-nucleotide polymorphisms in CYP2D6*10, CYP3A5*3, and CYP3A4*18B. Blood HCQ and DHCQ concentrations ([HCQ] and [DHCQ]) were measured and their association with corresponding genotypes was investigated. A total of 194 patients were included in the analysis. CYP2D6*10 polymorphisms (rs1065852 and rs1135840) were significantly associated with the [DHCQ]:[HCQ] ratio after adjustment for age, sex, dose per weight per day, and SLE Disease Activity Index score (P = 0.03 and P < 0.01, respectively). In adjusted models, the [DHCQ]:[HCQ] ratio was highest in patients with the G/G genotype of the CYP2D6*10 (rs1065852) polymorphism and lowest in those with the A/A genotype (P = 0.03). Similarly, the [DHCQ]:[HCQ] ratio was highest in patients with the C/C genotype of the CYP2D6*10 (rs1135840) polymorphism and lowest in those with the G/G genotype (P < 0.01). The CYP2D6*10 (rs1065852) polymorphism was significantly related to the [DHCQ] (P = 0.01). However, the polymorphisms of CYP3A5*3 and CYP3A4*18B did not show any significant association with the [HCQ], [DHCQ], or [DHCQ]:[HCQ] ratio. Our study showed that the [DHCQ]:[HCQ] ratio was related to CYP2D6 polymorphisms in Korean lupus patients taking oral HCQ. CYP polymorphisms may explain why there is wide variation in blood HCQ concentrations. The role of an individual's CYP polymorphisms should be considered when prescribing oral HCQ. © 2016, American College of Rheumatology.

Association of the F13A1 Val34Leu polymorphism and recurrent pregnancy loss: A meta-analysis.

PubMed

Jung, Jae Hyun; Kim, Jae-Hoon; Song, Gwan Gyu; Choi, Sung Jae

2017-08-01

Factor XIII (FXIII) plays role in stabilizing the linkage between fibrins during blood clotting and has been implicated in recurrent pregnancy loss (RPL). The relationship between the Val34Leu polymorphism in F13A1, which encodes the enzymatic subunit of FXIII, and RPL is unclear. The aim of this meta-analysis was to evaluate the association betweenF13A1 Val34Leu and the risk of RPL. We performed a meta-analysis of 11 studies involving 1092 cases and 678 controls using published literature from PubMed and Embase. We detected an association in recessive (Val/Val vs. Val/Leu+Leu/Leu; OR=0.71, 95% CI=0.51-0.99, P=0.04), and one of the two co-dominant (Val/Val vs. Val/Leu; OR=0.71, 95% CI=0.52-0.98, P=0.03) models of in heritance. Subgroup analysis revealed that the F13A1 Val34Leu polymorphism was associated with RPL in Asians (Val vs. Leu; OR=0.53, CI=0.33-0.85, P=0.01). However, there was no association between F13A1 Val34Leu and RPL in Europeans and South Americans. Our meta-analysis supports an association between F13A1 Val34Leu and RPL. Copyright © 2017 Elsevier B.V. All rights reserved.

Unexpected combined effects of NADH dehydrogenase subunit-2 237 Leu/Met polymorphism and green tea consumption on renal function in male Japanese health check-up examinees: a cross-sectional study.

PubMed

Kokaze, Akatsuki; Ishikawa, Mamoru; Matsunaga, Naomi; Karita, Kanae; Yoshida, Masao; Ohtsu, Tadahiro; Ochiai, Hirotaka; Shirasawa, Takako; Nanri, Hinako; Hoshino, Hiromi; Takashima, Yutaka

2013-11-20

NADH dehydrogenase subunit-2 237 leucine/methionine (ND2-237 Leu/Met) polymorphism is associated with longevity in Japanese. A previous study has shown that ND2-237 Leu/Met polymorphism modulates the effects of green tea consumption on risk of hypertension. For men with ND2-237Leu, habitual green tea consumption may reduce the risk of hypertension. Moreover, there is a combined effect of ND2-237 Leu/Met polymorphism and alcohol consumption on risk of mildly decreased estimated glomerular filtration rate (eGFR) (<90 ml/min/1.73 m2). Several beneficial effects of green tea on the kidney have been reported. The objective of this study was to investigate whether ND2-237 Leu/Met polymorphism modifies the effects of green tea consumption on risk of mildly decreased eGFR in male Japanese health check-up examinees. For ND2-237Leu genotypic men, after adjustment for confounding factors, green tea consumption may increase the risk of mildly decreased eGFR (P for trend = 0.016). The adjusted odds ratio (OR) for mildly decreased eGFR was significantly higher in subjects with ND2-237Leu who consume ≥6 cups of green tea per day than those who consume ≤1 cup of green tea per day (adjusted OR = 5.647, 95% confidence interval: 1.528-20.88, P = 0.009). On the other hand, for ND2-237Met genotypic men, green tea consumption does not appear to determine the risk of mildly decreased eGFR. The present results suggest that ND2-237 Leu/Met polymorphism unexpectedly modifies the effects of green tea consumption on eGFR and the risk of mildly decreased eGFR in male Japanese subjects.

Unexpected combined effects of NADH dehydrogenase subunit-2 237 Leu/Met polymorphism and green tea consumption on renal function in male Japanese health check-up examinees: a cross-sectional study

PubMed Central

2013-01-01

Background NADH dehydrogenase subunit-2 237 leucine/methionine (ND2-237 Leu/Met) polymorphism is associated with longevity in Japanese. A previous study has shown that ND2-237 Leu/Met polymorphism modulates the effects of green tea consumption on risk of hypertension. For men with ND2-237Leu, habitual green tea consumption may reduce the risk of hypertension. Moreover, there is a combined effect of ND2-237 Leu/Met polymorphism and alcohol consumption on risk of mildly decreased estimated glomerular filtration rate (eGFR) (<90 ml/min/1.73 m2). Several beneficial effects of green tea on the kidney have been reported. The objective of this study was to investigate whether ND2-237 Leu/Met polymorphism modifies the effects of green tea consumption on risk of mildly decreased eGFR in male Japanese health check-up examinees. Results For ND2-237Leu genotypic men, after adjustment for confounding factors, green tea consumption may increase the risk of mildly decreased eGFR (P for trend = 0.016). The adjusted odds ratio (OR) for mildly decreased eGFR was significantly higher in subjects with ND2-237Leu who consume ≥6 cups of green tea per day than those who consume ≤1 cup of green tea per day (adjusted OR = 5.647, 95% confidence interval: 1.528-20.88, P = 0.009). On the other hand, for ND2-237Met genotypic men, green tea consumption does not appear to determine the risk of mildly decreased eGFR. Conclusion The present results suggest that ND2-237 Leu/Met polymorphism unexpectedly modifies the effects of green tea consumption on eGFR and the risk of mildly decreased eGFR in male Japanese subjects. PMID:24252463

Structural analysis of photosystem I polypeptides using chemical crosslinking

NASA Technical Reports Server (NTRS)

Armbrust, T. S.; Odom, W. R.; Guikema, J. A.; Spooner, B. S. (Principal Investigator)

1994-01-01

Thylakoid membranes, obtained from leaves of 14 d soybean (Glycine max L. cv. Williams) plants, were treated with the chemical crosslinkers glutaraldehyde or 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) to investigate the structural organization of photosystem I. Polypeptides were resolved using lithium dodecyl sulfate polyacrylamide gel electrophoresis, and were identified by western blot analysis using a library of polyclonal antibodies specific for photosystem I subunits. An electrophoretic examination of crosslinked thylakoids revealed numerous crosslinked products, using either glutaraldehyde or EDC. However, only a few of these could be identified by western blot analysis using subunit-specific polyclonal antibodies. Several glutaraldehyde dependent crosslinked species were identified. A single band was identified minimally composed of PsaC and PsaD, documenting the close interaction between these two subunits. The most interesting aspect of these studies was a crosslinked species composed of the PsaB subunit observed following EDC treatment of thylakoids. This is either an internally crosslinked species, which will provide structural information concerning the topology of the complex PsaB protein, a linkage with a polypeptide for which we do not yet have an immunological probe, or a masking of epitopes by the EDC linkage at critical locations in the peptide which is linked to PsaB.

Molecular cloning and characterization of the α-glucosidase II from Bombyx mori and Spodoptera frugiperda.

PubMed

Watanabe, Satoko; Kakudo, Akemi; Ohta, Masato; Mita, Kazuei; Fujiyama, Kazuhito; Inumaru, Shigeki

2013-04-01

The α-glucosidase II (GII) is a heterodimer of α- and β-subunits and important for N-glycosylation processing and quality control of nascent glycoproteins. Although high concentration of α-glucosidase inhibitors from mulberry leaves accumulate in silkworms (Bombyx mori) by feeding, silkworm does not show any toxic symptom against these inhibitors and N-glycosylation of recombinant proteins is not affected. We, therefore, hypothesized that silkworm GII is not sensitive to the α-glucosidase inhibitors from mulberry leaves. However, the genes for B. mori GII subunits have not yet been identified, and the protein has not been characterized. Therefore, we isolated the B. mori GII α- and β-subunit genes and the GII α-subunit gene of Spodoptera frugiperda, which does not feed on mulberry leaves. We used a baculovirus expression system to produce the recombinant GII subunits and identified their enzyme characteristics. The recombinant GII α-subunits of B. mori and S. frugiperda hydrolyzed p-nitrophenyl α-d-glucopyranoside (pNP-αGlc) but were inactive toward N-glycan. Although the B. mori GII β-subunit was not required for the hydrolysis of pNP-αGlc, a B. mori GII complex of the α- and β-subunits was required for N-glycan cleavage. As hypothesized, the B. mori GII α-subunit protein was less sensitive to α-glucosidase inhibitors than was the S. frugiperda GII α-subunit protein. Our observations suggest that the low sensitivity of GII contributes to the ability of B. mori to evade the toxic effect of α-glucosidase inhibitors from mulberry leaves. Copyright © 2013 Elsevier Ltd. All rights reserved.

Polymorphisms in arsenic(+III oxidation state) methyltransferase (AS3MT) predict gene expression of AS3MT as well as arsenic metabolism.

PubMed

Engström, Karin; Vahter, Marie; Mlakar, Simona Jurkovic; Concha, Gabriela; Nermell, Barbro; Raqib, Rubhana; Cardozo, Alejandro; Broberg, Karin

2011-02-01

Arsenic (As) occurs as monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA) in humans, and the methylation pattern demonstrates large interindividual differences. The fraction of urinary MMA is a marker for susceptibility to As-related diseases. We evaluated the impact of polymorphisms in five methyltransferase genes on As metabolism in two populations, one in South America and one in Southeast Asia. The methyltransferase genes were arsenic(+III oxidation state) methyltransferase (AS3MT), DNA-methyltransferase 1a and 3b (DNMT1a and DNMT3b, respectively), phosphatidylethanolamine N-methyltransferase (PEMT), and betaine-homocysteine methyltransferase (BHMT). AS3MT expression was analyzed in peripheral blood. Subjects were women exposed to As in drinking water in the Argentinean Andes [n = 172; median total urinary As (U-As), 200 µg/L] and in rural Bangladesh (n = 361; U-As, 100 µg/L; all in early pregnancy). Urinary As metabolites were measured by high-pressure liquid chromatography/inductively coupled plasma mass spectrometry. Polymorphisms (n = 22) were genotyped with Sequenom, and AS3MT expression was measured by quantitative real-time polymerase chain reaction using TaqMan expression assays. Six AS3MT polymorphisms were significantly associated with As metabolite patterns in both populations (p ≤ 0.01). The most frequent AS3MT haplotype in Bangladesh was associated with a higher percentage of MMA (%MMA), and the most frequent haplotype in Argentina was associated with a lower %MMA and a higher percentage of DMA. Four polymorphisms in the DNMT genes were associated with metabolite patterns in Bangladesh. Noncoding AS3MT polymorphisms affected gene expression of AS3MT in peripheral blood, demonstrating that one functional impact of AS3MT polymorphisms may be altered levels of gene expression. Polymorphisms in AS3MT significantly predicted As metabolism across these two very different populations, suggesting that AS3MT may have an impact on As metabolite patterns in populations worldwide.

Subunit composition and structure of subcomponent C1q of the first component of human complement.

PubMed

Reid, K B; Porter, R R

1976-04-01

1. Unreduced human subcomponent C1q was shown by electrophoresis on polyacrylamide gels run in the presence of sodium dodecyl sulphate to be composed of two types of non-covalently linked subunits of apparent mol.wts. 69 000 and 54 000. The ratio of the two subunits was markedly affected by the ionic strength of the applied sample. At a low ionic strength of applied sample, which gave the optimum value for the 54 000-apparent mol.wt. subunit, a ratio of 1.99:1.00 was obtained for the ratio of the 69 000-apparent mol.wt. subunit to the 5400-apparent-mol.wt. subunit. The amount of the 54 000-apparent-mol.wt. subunit detected in the expected position on the gel was found to be inversely proportional to increases in the ionic strength of the applled sample. 2. Human subcomponent C1q on reduction and alkylation, or oxidation, yields equimolar amounts of three chains designated A, B and C [Reid et al. (1972) Biochem. J. 130, 749-763]. The results obtained by Yonemasu & Stroud [(1972) Immunochemistry 9, 545-554], which showed that the 69 000-apparent-mol.wt. subunit was a disulphide-linked dimer of the A and B chains and that the 54 000-apparent-mol.wt. subunit was a disulphide-linked dimer of the C chain, were confirmed. 3. Gel filtration on Sephadex G-200 in 6.0M-guanidinium chloride showed that both types of unreduced subunit were eluted together as a single symmetrical peak of apparent mol.wt. 49 000-50 000 when globular proteins were used as markers. The molecular weights of the oxidized or reduced A, B and C chains have been shown previously to be very similar all being in the range 23 000-24 000 [Reid et al. (1972) Biochem. J. 130, 749-763; Reid (1974) Biochem. J. 141, 189-203]. 4. It is proposed that subcomponent C1q (mol.wt. 410000) is composed of nine non-covalently linked subunits, i.e. six A-B dimers and three C-C dimers. 5. A structure for subcomponent C1q is proposed and is based on the assumption that the collagen-like regions of 78 residues in each of the A, B and C chains are combined to form a triple-helical structure of the same type as is found in collagens.

Evaluation of the impact of genetic polymorphisms in glutathione-related genes on the association between methylmercury or n-3 polyunsaturated long chain fatty acids and risk of myocardial infarction: a case-control study

PubMed Central

2011-01-01

Background The n-3 polyunsaturated fatty acids eicosapentaenoic acid and docosahexaenoic acid, which are present in fish, are protective against myocardial infarction. However, fish also contains methylmercury, which influences the risk of myocardial infarction, possibly by generating oxidative stress. Methylmercury is metabolized by conjugation to glutathione, which facilitates elimination. Glutathione is also an antioxidant. Individuals with certain polymorphisms in glutathione-related genes may tolerate higher exposures to methylmercury, due to faster metabolism and elimination and/or better glutathione-associated antioxidative capacity. They would thus benefit more from the protective agents in fish, such as eicosapentaenoic+docosahexaenoic acid and selenium. The objective for this study was to elucidate whether genetic polymorphisms in glutathione-related genes modify the association between eicosapentaenoic+docosahexaenoic acid or methylmercury and risk of first ever myocardial infarction. Methods Polymorphisms in glutathione-synthesizing (glutamyl-cysteine ligase catalytic subunit, GCLC and glutamyl-cysteine ligase modifier subunit, GCLM) or glutathione-conjugating (glutathione S-transferase P, GSTP1) genes were genotyped in 1027 individuals from northern Sweden (458 cases of first-ever myocardial infarction and 569 matched controls). The impact of these polymorphisms on the association between erythrocyte-mercury (proxy for methylmercury) and risk of myocardial infarction, as well as between plasma eicosapentaenoic+docosahexaenoic acid and risk of myocardial infarction, was evaluated by conditional logistic regression. The effect of erythrocyte-selenium on risk of myocardial infarction was also taken into consideration. Results There were no strong genetic modifying effects on the association between plasma eicosapentaenoic+docosahexaenoic acid or erythrocyte-mercury and risk of myocardial infarction risk. When eicosapentaenoic+docosahexaenoic acid or erythrocyte-mercury were divided into tertiles, individuals with GCLM-588 TT genotype displayed a lower risk relative to the CC genotype in all but one tertile; in most tertiles the odds ratio was around 0.5 for TT. However, there were few TT carriers and the results were not statistically significant. The results were similar when taking plasma eicosapentaenoic+docosahexaenoic acid, erythrocyte-selenium and erythrocyte-mercury into account simultaneously. Conclusions No statistically significant genetic modifying effects were seen for the association between plasma eicosapentaenoic+docosahexaenoic acid or erythrocyte-mercury and risk of myocardial infarction. Still, our results indicate that the relatively rare GCLM-588 TT genotype may have an impact, but a larger study is necessary for confirmation. PMID:21504558

Genetic polymorphism of interleukin-1A (IL-1A), IL-1B, and IL-1 receptor antagonist (IL-1RN) and prostate cancer risk.

PubMed

Xu, Hua; Ding, Qiang; Jiang, Hao-Wen

2014-01-01

We aimed to investigate the associations between polymorphisms of interleukin-1A (IL-1A), IL-1B, and IL-1 receptor antagonist (IL-1RN) and prostate cancer (PCa) risk. A comprehensive search for articles of MEDLINE and EMBASE databases and bibliographies of retrieved articles published up to August 3, 2014 was performed. Methodological quality assessment of the trials was based on a standard quality scoring system. The meta-analysis was performed using STATA 12.0. We included 9 studies (1 study for IL-1A, 5 studies for IL-1B, and 3 studies for IL-1RN), and significant association was found between polymorphisms of IL-1B-511 (rs16944) as well as IL-1B-31 (rs1143627) and PCa risk. IL-1B-511 (rs16944) polymorphism was significantly associated with PCa risk in homozygote and recessive models, as well as allele contrast (TT vs CC: OR, 0.74; 95%CI, 0.58-0.94; P=0.012; TT vs TC+CC; OR, 0.79; 95%CI, 0.63-0.98; P=0.033; T vs C: OR, 0.86; 95%CI, 0.77-0.96; P=0.008). The association between IL-1B-31 (rs1143627) polymorphism and PCa risk was weakly significant under a heterozygote model (OR, 1.35; 95%CI, 1.00-1.80; P=0.047). Sequence variants in IL-1B-511 (rs16944) and IL-1B-31 (rs1143627) are significantly associated with PCa risk, which provides additional novel evidence that proinflammatory cytokines and inflammation play an important role in the etiology of PCa.

Reverse-phase HPLC analysis of human alpha crystallin.

PubMed

Swamy, M S; Abraham, E C

1991-03-01

A rapid and highly sensitive reverse-phase HPLC (RP-HPLC) method was used to separate crystallin subunits from human alpha crystallin. Three distinct peaks were separated; by electrophoretic and immunological analyses the first and second peaks were identified as alpha B and alpha A respectively. On the other hand, peak 3 appeared to be a modified form of alpha crystallin. The ratio of alpha A and alpha B proteins was 3:1 in 1 day old lenses which gradually changed to 2:1 in 17 year old lenses and to 1:1 in the 50 and 82 year old whole lenses and 82 year old lens cortex, with a concomitant increase in the modified alpha, suggesting that alpha A subunits are relatively more involved in aggregation. Analysis of the 82 year old lens nucleus also supported this conclusion. The RP-HPLC analysis of the HMW aggregate fraction showed substantial enrichment of the modified alpha. The alpha A and alpha B subunits independently reassociated to form polymeric alpha crystallin whereas the modified alpha reassociated to form HMW aggregates as shown by molecular sieve HPLC. Hence it appears that the HMW aggregate peak was constituted by modified alpha crystallin. Only in the peak 3 material the 280 nm absorbance was about 2-fold higher than what was expected from the actual protein content. The data suggest that the changes induced by post-translational modifications may have some role in the formation of modified alpha. The present RP-HPLC method is useful in separating these modified alpha from the unmodified alpha A and alpha B subunits.

Regulation of vacuolar H{sup +}-ATPase in microglia by RANKL

DOE Office of Scientific and Technical Information (OSTI.GOV)

Serrano, Eric M.; Ricofort, Ryan D.; Zuo, Jian

2009-11-06

Vacuolar H{sup +}-ATPases (V-ATPases) are large electrogenic proton pumps composed of numerous subunits that play vital housekeeping roles in the acidification of compartments of the endocytic pathway. Additionally, V-ATPases play specialized roles in certain cell types, a capacity that is linked to cell type selective expression of isoforms of some of the subunits. We detected low levels of the a3 isoform of the a-subunit in mouse brain extracts. Examination of various brain-derived cell types by immunoblotting showed a3 was expressed in the N9 microglia cell line and in primary microglia, but not in other cell types. The expression of a3more » in osteoclasts requires stimulation by Receptor Activator of Nuclear Factor {kappa}B-ligand (RANKL). We found that Receptor Activator of Nuclear Factor {kappa}B (RANK) was expressed by microglia. Stimulation of microglia with RANKL triggered increased expression of a3. V-ATPases in microglia were shown to bind microfilaments, and stimulation with RANKL increased the proportion of V-ATPase associated with the detergent-insoluble cytoskeletal fraction and with actin. In summary, microglia express the a3-subunit of V-ATPase. The expression of a3 and the interaction between V-ATPases and microfilaments was modulated by RANKL. These data suggest a novel molecular pathway for regulating microglia.« less

2-Methyltetrahydro-3-benzazepin-1-ols - The missing link in SAR of GluN2B selective NMDA receptor antagonists.

PubMed

Dey, Sougata; Schepmann, Dirk; Wünsch, Bernhard

2018-01-15

The NMDA receptor containing GluN2B subunits represents a promising target for the development of drugs for the treatment of various neurological disorders including neurodegenerative diseases. In order to study the role of CH 3 and OH moieties trisubstituted tetrahydro-3-benzazepines 4 were designed as missing link between tetra- and disubstituted 3-benzazepines 2 and 5. The synthesis of 4 comprises eight reaction steps starting from alanine. The intramolecular Friedel-Crafts acylation to obtain the ketone 12 and the base-catalyzed elimination of trifluoromethanesulfinate (CF 3 SO 2 - ) followed by NaBH 4 reduction represent the key steps. The GluN2B affinity of the cis-configured 3-benzazepin-1-ol cis-4a with a 4-phenylbutyl side chain (K i  = 252 nM) is considerably lower than the GluN2B affinity of (R,R)-2 (K i  = 17 nM) indicating the importance of the phenolic OH moiety for the interaction with the receptor protein. Introduction of an additional CH 3 moiety in 2-position led to a slight decrease of GluN2B affinity as can be seen by comparing the affinity data of cis-4a and 5. The homologous phenylpentyl derivative cis-4b shows the highest GluN2B affinity (K i  = 56 nM) of this series of compounds. According to docking studies cis-4a adopts the same binding mode as the cocrystallized ligand ifenprodil-keto 1A and 5 at the interface of the GluN2B and GluN1a subunits. The same crucial H-bonds are formed between the C(O)NH 2 moiety of Gln110 within the GluN2B subunit and the protonated amino moiety and the OH moiety of (R,R)-cis-4a. Copyright © 2017 Elsevier Ltd. All rights reserved.

Subunit stoichiometry of the CNG channel of rod photoreceptors.

PubMed

Weitz, Dietmar; Ficek, Nicole; Kremmer, Elisabeth; Bauer, Paul J; Kaupp, U Benjamin

2002-12-05

Cyclic nucleotide-gated (CNG) channels play a central role in the conversion of sensory stimuli into electrical signals. CNG channels form heterooligomeric complexes built of A and B subunits. Here, we study the subunit stoichiometry of the native rod CNG channel by chemical crosslinking. The apparent molecular weight (M(w)) of each crosslink product was determined by SDS-PAGE, and its composition was analyzed by Western blotting using antibodies specific for the A1 or B1 subunit. The number of crosslink products and their M(w) as well as the immunological identification of A1 and B1 subunits in the crosslink products led us to conclude that the native rod CNG channel is a tetramer composed of three A1 and one B1 subunit. This is an example of violation of symmetry in tetrameric channels.

Molecular genetics of G proteins and atherosclerosis risk.

PubMed

Siffert, W

2001-11-01

Using a classical candidate gene approach, we have described a common C825T polymorphism in the gene GNB3 which encodes the ubiquitously expressed beta3 subunit of heterotrimeric G proteins. The 825T allele is associated with alternative splicing of the gene and the formation of a truncated but functionally active beta3 subunit which is referred to as Gbeta3s. Expression of the splice variant results in an enhanced G protein activation on stimulation of G protein-coupled receptors. Carriers of the 825T allele show an increased risk for hypertension and left ventricular hypertrophy. Homo- and heterozygous 825T allele carriers respond with a stronger decrease in blood pressure to therapy with a thiazide diuretic than homozygous 825C allele carriers. Moreover, 825T allele carriers appear to have an increased risk for obesity which appears sensible given the established role of G protein signaling in adipogenesis. The highest frequencies of the 825T allele are found in ethnicities with the highest lifestyle-dependent risk for obesity, e.g., black Africans and East Asians. This suggests that the 825T allele fulfills the criteria of a thrifty genotype.

Prognostic role of the CDNK1B V109G polymorphism in multiple endocrine neoplasia type 1

PubMed Central

Circelli, Luisa; Ramundo, Valeria; Marotta, Vincenzo; Sciammarella, Concetta; Marciello, Francesca; Del Prete, Michela; Sabatino, Lina; Pasquali, Daniela; Izzo, Francesco; Scala, Stefania; Colao, Annamaria; Faggiano, Antongiulio; Colantuoni, Vittorio

2015-01-01

CDKN1B encodes the cyclin-dependent kinase inhibitor p27/Kip1. CDKN1B mutations and polymorphisms are involved in tumorigenesis; specifically, the V109G single nucleotide polymorphism has been linked to different tumours with controversial results. Multiple endocrine neoplasia type 1 (MEN1) is a rare autosomal dominant syndrome, characterized by the development of different types of neuroendocrine tumours and increased incidence of other malignancies. A clear genotype–phenotype correlation in MEN1 has not been established yet. In this study, we assessed whether the CDKN1B V109G polymorphism was associated with the development of aggressive tumours in 55 consecutive patients affected by MEN1. The polymorphism was investigated by PCR amplification of germline DNA followed by direct sequencing. Baseline and follow-up data of tumour types and their severity were collected and associated with the genetic data. MEN1-related aggressive and other malignant tumours of any origin were detected in 16.1% of wild-type and 33.3% of polymorphism allele-bearing patients (P = NS). The time interval between birth and the first aggressive tumour was significantly shorter in patients with the CDKN1B V109G polymorphism (median 46 years) than in those without (median not reached; P = 0.03). Similarly, shorter was the time interval between MEN1 diagnosis and age of the first aggressive tumour (P = 0.02). Overall survival could not be estimated as 96% patients were still alive at the time of the study. In conclusion, CDKN1B V109G polymorphism seems to play a role in the development of aggressive tumours in MEN1. PMID:25824098

Association of UGT2B7 and UGT1A4 Polymorphisms with Serum Concentration of Antiepileptic Drugs in Children.

PubMed

Du, Zhongliang; Jiao, Yukun; Shi, Lianting

2016-10-31

BACKGROUND This study aimed to analyze the relationship of UGT2B7 and UGT1A4 polymorphisms with metabolism of valproic acid (VPA) and lamotrigine (LTG) in epileptic children. MATERIAL AND METHODS We administered VPA (102) and LTG (102) to 204 children with epilepsy. Blood samples were collected before the morning dose. Serum concentration of LTG was measured by high-performance liquid chromatography (HPLC). Serum VPA concentration was tested by fluorescence polarization immunoassay. UGT2B7 A268G, C802T, and G211T polymorphisms, as well as UGT1A4 L48V polymorphism, were assayed by direct automated DNA sequencing after PCR. Evaluation of efficacy was conducted using the Engel method. RESULTS The adjusted serum concentration of VPA was 4.26 μg/mL per mg/kg and LTG was 1.56 μg/mL per mg/kg. Multiple linear regression analysis revealed that VPA or LTG adjusted concentration showed a good linear relation with sex and age. UGT2B7 A268G and C802T polymorphisms were demonstrated to affect the serum concentration of VPA (F=3.147, P=0.047; F=22.754, P=0.000). UGT1A4 L48V polymorphism was not related with the serum concentration of LTG (F=5.328, P=0.006). In the efficacy analysis, we found that C802T polymorphism exerted strong effects on efficacy of VPA (χ²=9.265, P=0.010). L48V polymorphism also showed effects on efficacy of LTG (χ²=17.397, P=0.001). CONCLUSIONS UGT2B7, UGT1A4 polymorphisms play crucial roles in metabolism of VPA and LTG.

Designing B- and T-cell multi-epitope based subunit vaccine using immunoinformatics approach to control Zika virus infection.

PubMed

Kumar Pandey, Rajan; Ojha, Rupal; Mishra, Amit; Kumar Prajapati, Vijay

2018-06-14

The Zika virus is a rapidly spreading Aedes mosquito-borne sickness, which creates an unanticipated linkage birth deformity and neurological turmoil. This study represents the use of the combinatorial immunoinformatics approach to develop a multiepitope subunit vaccine using the structural and nonstructural proteins of the Zika virus. The designed subunit vaccine consists of cytotoxic T-lymphocyte and helper T-lymphocyte epitopes accompanied by suitable adjuvant and linkers. The presence of humoral immune response specific B-cell epitopes was also confirmed by B-cell epitope mapping among vaccine protein. Further, the vaccine protein was characterized for its allergenicity, antigenicity, and physiochemical parameters and found to be safe and immunogenic. Molecular docking and molecular dynamics studies of the vaccine protein with the toll-like receptor-3 were performed to ensure the binding affinity and stability of their complex. Finally, in silico cloning was performed for the effective expression of vaccine construct in the microbial system (Escherichia coli K12 strain). Aforementioned approaches result in the multiepitope subunit vaccine which may have the ability to induce cellular as well as humoral immune response. Moreover, this study needs the experimental validation to prove the immunogenic and protective behavior of the developed subunit vaccine. © 2018 Wiley Periodicals, Inc., A Wiley Company.

Genetic variants in GCKR and PNPLA3 confer susceptibility to nonalcoholic fatty liver disease in obese individuals.

PubMed

Lin, Yu-Cheng; Chang, Pi-Feng; Chang, Mei-Hwei; Ni, Yen-Hsuan

2014-04-01

A genome-wide association study identified variants in or near patatin-like phospholipase domain-containing-3 (PNPLA3), neurocan (NCAN), lysophospholipase-like 1 (LYPLAL1), glucokinase regulatory protein (GCKR), and protein phosphatase 1 regulatory subunit 3b (PPP1R3B) that were strongly associated with nonalcoholic fatty liver disease (NAFLD) in adults of European ancestry. We examined these genetic variants in obese children and tested whether their effects on NAFLD are significant in the Taiwanese Han Chinese population. We genotyped PNPLA3 rs738409, NCAN rs2228603, LYPLAL1 rs12137855, GCKR rs780094, and PPP1R3B rs4240624 in 797 obese children aged 7-18 y. NAFLD was identified by liver ultrasonography. We analyzed the effect of these genetic variants on NAFLD. NAFLD was identified in 24% of the recruited obese children. We found significant associations with NAFLD at variants in PNPLA3 and GCKR but not in NCAN, LYPLAL1, and PPP1R3B. Multiple logistic regression analysis showed that, after control for the effects of age- and sex-adjusted body mass index, waist-to-hip ratio, sex, and PNPLA3 rs738409 polymorphism, the variant GCKR rs780094 TT genotype independently increased the OR of NAFLD by 1.997 (95% CI: 1.196, 3.335; P = 0.008) compared with the CC genotype. Subjects with the variant GCKR rs780094 TT genotype had a higher mean serum alanine aminotransferase concentration than did those with the CC genotype (30.8 ± 34.7 compared with 22.2 ± 18.6 IU/L; P = 0.01). By studying the genetic variants of obese Taiwanese children, we confirmed that the genetic variants in GCKR rs780094 and PNPLA3 rs738409, but not in NCAN rs2228603, LYPLAL1 rs12137855, and PPP1R3B rs4240624, are associated with an increased risk of NAFLD. GCKR and PNPLA3 variants are the common genetic factors that may confer susceptibility to NAFLD in obese individuals across multiple ethnic groups.

Two structural components in CNGA3 support regulation of cone CNG channels by phosphoinositides.

PubMed

Dai, Gucan; Peng, Changhong; Liu, Chunming; Varnum, Michael D

2013-04-01

Cyclic nucleotide-gated (CNG) channels in retinal photoreceptors play a crucial role in vertebrate phototransduction. The ligand sensitivity of photoreceptor CNG channels is adjusted during adaptation and in response to paracrine signals, but the mechanisms involved in channel regulation are only partly understood. Heteromeric cone CNGA3 (A3) + CNGB3 (B3) channels are inhibited by membrane phosphoinositides (PIP(n)), including phosphatidylinositol 3,4,5-triphosphate (PIP(3)) and phosphatidylinositol 4,5-bisphosphate (PIP(2)), demonstrating a decrease in apparent affinity for cyclic guanosine monophosphate (cGMP). Unlike homomeric A1 or A2 channels, A3-only channels paradoxically did not show a decrease in apparent affinity for cGMP after PIP(n) application. However, PIP(n) induced an ∼2.5-fold increase in cAMP efficacy for A3 channels. The PIP(n)-dependent change in cAMP efficacy was abolished by mutations in the C-terminal region (R643Q/R646Q) or by truncation distal to the cyclic nucleotide-binding domain (613X). In addition, A3-613X unmasked a threefold decrease in apparent cGMP affinity with PIP(n) application to homomeric channels, and this effect was dependent on conserved arginines within the N-terminal region of A3. Together, these results indicate that regulation of A3 subunits by phosphoinositides exhibits two separable components, which depend on structural elements within the N- and C-terminal regions, respectively. Furthermore, both N and C regulatory modules in A3 supported PIP(n) regulation of heteromeric A3+B3 channels. B3 subunits were not sufficient to confer PIP(n) sensitivity to heteromeric channels formed with PIP(n)-insensitive A subunits. Finally, channels formed by mixtures of PIP(n)-insensitive A3 subunits, having complementary mutations in N- and/or C-terminal regions, restored PIP(n) regulation, implying that intersubunit N-C interactions help control the phosphoinositide sensitivity of cone CNG channels.

Two structural components in CNGA3 support regulation of cone CNG channels by phosphoinositides

PubMed Central

Dai, Gucan; Peng, Changhong; Liu, Chunming

2013-01-01

Cyclic nucleotide-gated (CNG) channels in retinal photoreceptors play a crucial role in vertebrate phototransduction. The ligand sensitivity of photoreceptor CNG channels is adjusted during adaptation and in response to paracrine signals, but the mechanisms involved in channel regulation are only partly understood. Heteromeric cone CNGA3 (A3) + CNGB3 (B3) channels are inhibited by membrane phosphoinositides (PIPn), including phosphatidylinositol 3,4,5-triphosphate (PIP3) and phosphatidylinositol 4,5-bisphosphate (PIP2), demonstrating a decrease in apparent affinity for cyclic guanosine monophosphate (cGMP). Unlike homomeric A1 or A2 channels, A3-only channels paradoxically did not show a decrease in apparent affinity for cGMP after PIPn application. However, PIPn induced an ∼2.5-fold increase in cAMP efficacy for A3 channels. The PIPn-dependent change in cAMP efficacy was abolished by mutations in the C-terminal region (R643Q/R646Q) or by truncation distal to the cyclic nucleotide-binding domain (613X). In addition, A3-613X unmasked a threefold decrease in apparent cGMP affinity with PIPn application to homomeric channels, and this effect was dependent on conserved arginines within the N-terminal region of A3. Together, these results indicate that regulation of A3 subunits by phosphoinositides exhibits two separable components, which depend on structural elements within the N- and C-terminal regions, respectively. Furthermore, both N and C regulatory modules in A3 supported PIPn regulation of heteromeric A3+B3 channels. B3 subunits were not sufficient to confer PIPn sensitivity to heteromeric channels formed with PIPn-insensitive A subunits. Finally, channels formed by mixtures of PIPn-insensitive A3 subunits, having complementary mutations in N- and/or C-terminal regions, restored PIPn regulation, implying that intersubunit N–C interactions help control the phosphoinositide sensitivity of cone CNG channels. PMID:23530136

Genomic polymorphism, recombination, and linkage disequilibrium in human major histocompatibility complex-encoded antigen-processing genes.

PubMed Central

van Endert, P M; Lopez, M T; Patel, S D; Monaco, J J; McDevitt, H O

1992-01-01

Recently, two subunits of a large cytosolic protease and two putative peptide transporter proteins were found to be encoded by genes within the class II region of the major histocompatibility complex (MHC). These genes have been suggested to be involved in the processing of antigenic proteins for presentation by MHC class I molecules. Because of the high degree of polymorphism in MHC genes, and previous evidence for both functional and polypeptide sequence polymorphism in the proteins encoded by the antigen-processing genes, we tested DNA from 27 consanguineous human cell lines for genomic polymorphism by restriction fragment length polymorphism (RFLP) analysis. These studies demonstrate a strong linkage disequilibrium between TAP1 and LMP2 RFLPs. Moreover, RFLPs, as well as a polymorphic stop codon in the telomeric TAP2 gene, appear to be in linkage disequilibrium with HLA-DR alleles and RFLPs in the HLA-DO gene. A high rate of recombination, however, seems to occur in the center of the complex, between the TAP1 and TAP2 genes. Images PMID:1360671

Expression of human inducible nitric oxide synthase in a tetrahydrobiopterin (H4B)-deficient cell line: H4B promotes assembly of enzyme subunits into an active dimer.

PubMed Central

Tzeng, E; Billiar, T R; Robbins, P D; Loftus, M; Stuehr, D J

1995-01-01

Murine inducible nitric oxide (NO) synthase (iNOS) is catalytically active only in dimeric form. Assembly of its purified subunits into a dimer requires H4B. To understand the structure-activity relationships of human iNOS, we constitutively expressed recombinant human iNOS in NIH 3T3 cells by using a retroviral vector. These cells are deficient in de novo H4B biosynthesis and the role of H4B in the expression and assembly of active iNOS in an intact cell system could be studied. In the absence of added H4B, NO synthesis by the cells was minimal, whereas cells grown with supplemental H4B or the H4B precursor sepiapterin generated NO (74.1 and 63.3 nmol of nitrite per 10(6) cells per 24 h, respectively). NO synthesis correlated with an increase in intracellular H4B but no increase in iNOS protein. Instead, an increased percentage of dimeric iNOS was observed, rising from 20% in cytosols from unsupplemented cells to 66% in H4B-supplemented cell cytosols. In all cases, only dimeric iNOS displayed catalytic activity. Cytosols prepared from H4B-deficient cells exhibited little iNOS activity but acquired activity during a 60- to 120-min incubation with H4B, reaching final activities of 60-72 pmol of citrulline per mg of protein per min. Reconstitution of cytosolic NO synthesis activity was associated with conversion of monomers into dimeric iNOS during the incubation. Thus, human iNOS subunits dimerize to form an active enzyme, and H4B plays a critical role in promoting dimerization in intact cells. This reveals a post-translational mechanism by which intracellular H4B can regulate iNOS expression. Images Fig. 1 Fig. 3 Fig. 4 Fig. 5 PMID:8524846

[Allelic variation at high-molecular-weight glutenin subunit loci in Aegilops biuncialis Vis].

PubMed

Kozub, N A; Sozinov, I A; Ksinias, I N; Sozinov, A A

2011-09-01

Alleles at the high-molecular-weight glutenin subunit loci Glu-U1 and Glu-M(b)1 were analyzed in the tetraploid species Aegilops biuncialis (UUM(b)M(b)). The material for the investigation included the collection of 39 accessions of Ae. biuncialis from Ukraine (the Crimea), one Hellenic accession, one accession of unknown origin, F2 seeds from different crosses, as well as samples from natural populations from the Crimea. Ae. umbellulata and Ae. comosa accessions were used to allocate components of the HMW glutenin subunit patterns of Ae. biuncialis to U or M(b) genomes. Eight alleles were identified at the Glu-U1 locus and ten alleles were revealed at the Glu-M(b) 1 locus. Among alleles at the Glu-M(b) 1 locus ofAe. biuncialis there were two alleles controlling the y-type subunit only and one allele encoding the x-subunit only.

The Large Subunit rDNA Sequence of Plasmodiophora brassicae Does not Contain Intra-species Polymorphism

PubMed Central

Schwelm, Arne; Berney, Cédric; Dixelius, Christina; Bass, David; Neuhauser, Sigrid

2016-01-01

Clubroot disease caused by Plasmodiophora brassicae is one of the most important diseases of cultivated brassicas. P. brassicae occurs in pathotypes which differ in the aggressiveness towards their Brassica host plants. To date no DNA based method to distinguish these pathotypes has been described. In 2011 polymorphism within the 28S rDNA of P. brassicae was reported which potentially could allow to distinguish pathotypes without the need of time-consuming bioassays. However, isolates of P. brassicae from around the world analysed in this study do not show polymorphism in their LSU rDNA sequences. The previously described polymorphism most likely derived from soil inhabiting Cercozoa more specifically Neoheteromita-like glissomonads. Here we correct the LSU rDNA sequence of P. brassicae. By using FISH we demonstrate that our newly generated sequence belongs to the causal agent of clubroot disease. PMID:27750174

A Common Polymorphism in SCN2A Predicts General Cognitive Ability through Effects on PFC Physiology.

PubMed

Scult, Matthew A; Trampush, Joey W; Zheng, Fengyu; Conley, Emily Drabant; Lencz, Todd; Malhotra, Anil K; Dickinson, Dwight; Weinberger, Daniel R; Hariri, Ahmad R

2015-09-01

Here we provide novel convergent evidence across three independent cohorts of healthy adults (n = 531), demonstrating that a common polymorphism in the gene encoding the α2 subunit of neuronal voltage-gated type II sodium channels (SCN2A) predicts human general cognitive ability or "g." Using meta-analysis, we demonstrate that the minor T allele of a common polymorphism (rs10174400) in SCN2A is associated with significantly higher "g" independent of gender and age. We further demonstrate using resting-state fMRI data from our discovery cohort (n = 236) that this genetic advantage may be mediated by increased capacity for information processing between the dorsolateral PFC and dorsal ACC, which support higher cognitive functions. Collectively, these findings fill a gap in our understanding of the genetics of general cognitive ability and highlight a specific neural mechanism through which a common polymorphism shapes interindividual variation in "g."

75 FR 27690 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Ambrosia...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-18

... Habitat Conservation Plan (Western Riverside County MSHCP), and Subarea Plans (City of San Diego and.... Subunit 3B is located in the City of Temecula in southwestern Riverside County, California. This subunit... grassland habitat type, which allows adequate sunlight and airflow for A. pumila (PCE 2). The physical and...

Evidence for Noncanonical Neurotransmitter Activation: Norepinephrine as a Dopamine D2-Like Receptor Agonist

PubMed Central

Sánchez-Soto, Marta; Bonifazi, Alessandro; Cai, Ning Sheng; Ellenberger, Michael P.; Newman, Amy Hauck

2016-01-01

The Gαi/o-coupled dopamine D2-like receptor family comprises three subtypes: the D2 receptor (D2R), with short and long isoform variants (D2SR and D2LR), D3 receptor (D3R), and D4 receptor (D4R), with several polymorphic variants. The common overlap of norepinephrine innervation and D2-like receptor expression patterns prompts the question of a possible noncanonical action by norepinephrine. In fact, previous studies have suggested that norepinephrine can functionally interact with D4R. To our knowledge, significant interactions between norepinephrine and D2R or D3R receptors have not been demonstrated. By using radioligand binding and bioluminescent resonance energy transfer (BRET) assays in transfected cells, the present study attempted a careful comparison between dopamine and norepinephrine in their possible activation of all D2-like receptors, including the two D2R isoforms and the most common D4R polymorphic variants. Functional BRET assays included activation of G proteins with all Gαi/o subunits, adenylyl cyclase inhibition, and β arrestin recruitment. Norepinephrine acted as a potent agonist for all D2-like receptor subtypes, with the general rank order of potency of D3R > D4R ≥ D2SR ≥ D2L. However, for both dopamine and norepinephrine, differences depended on the Gαi/o protein subunit involved. The most striking differences were observed with Gαi2, where the rank order of potencies for both dopamine and norepinephrine were D4R > D2SR = D2LR >> D3R. Furthermore the results do not support the existence of differences in the ability of dopamine and norepinephrine to activate different human D4R variants. The potency of norepinephrine for adrenergic α2A receptor was only about 20-fold higher compared with D3R and D4R across the three functional assays. PMID:26843180

Association between polymorphisms at promoters of XRCC5 and XRCC6 genes and risk of breast cancer.

PubMed

Rajaei, Mehrdad; Saadat, Iraj; Omidvari, Shahpour; Saadat, Mostafa

2014-04-01

Variation in DNA repair genes is one of the mechanisms that may lead to variation in DNA repair capacity. Ku, a heterodimeric DNA-binding complex, is directly involved in repair of DNA double-strand breaks. Ku consists of two subunits, Ku70 and Ku80, which are encoded by the XRCC6 and XRCC5 genes, respectively. In the present study, we investigated whether common genetic variant in variable number of tandem repeats (VNTR) XRCC5 and T-991C XRCC6 was associated with an altered risk of breast cancer. The present study included 407 females with breast cancer and 395 age frequency-matched controls which were randomly selected from the healthy female blood donors. The XRCC5 and XRCC6 polymorphisms were determined using PCR-based methods. For XRCC5 polymorphism, in comparison with the 1R/1R genotype, the 0R/0R genotype increased breast cancer risk (OR 9.55, 95%CI 1.19-76.64, P = 0.034). The 1R/3R genotype compared with 1R/1R genotype decreased the risk of breast cancer (Fisher's exact test P = 0.015). There was no association between T-991C polymorphism of XRCC6 and breast cancer risk. Mean of age at diagnosis of breast cancer for 0, 1, 2, 3, and >4 repeat in XRCC5 were 39.2, 41.9, 44.3, 45.8, and 47.3 years, respectively. The Kaplan-Meier survival analysis revealed that the number of repeat was associated with age at diagnosis of breast cancer (log rank statistic = 13.90, df = 4, P = 0.008). The findings of the present study revealed that either breast cancer risk or age at diagnosis of breast cancer was associated with the VNTR polymorphism at promoter region of XRCC5.

Exploiting transplastomically modified Rubisco to rapidly measure natural diversity in its carbon isotope discrimination using tuneable diode laser spectroscopy.

PubMed

von Caemmerer, Susanne; Tazoe, Youshi; Evans, John R; Whitney, Spencer M

2014-07-01

Carbon isotope discrimination (Δ) during C3 photosynthesis is dominated by the fractionation occurring during CO2-fixation by the enzyme Rubisco. While knowing the fractionation by enzymes is pivotal to fully understanding plant carbon metabolism, little is known about variation in the discrimination factor of Rubisco (b) as it is difficult to measure using existing in vitro methodologies. Tuneable diode laser absorption spectroscopy has improved the ability to make rapid measurements of Δ concurrently with photosynthetic gas exchange. This study used this technique to estimate b in vivo in five tobacco (Nicotiana tabacum L. cv Petit Havana [N,N]) genotypes expressing alternative Rubisco isoforms. For transplastomic tobacco producing Rhodospirillum rubrum Rubisco b was 23.8±0.7‰, while Rubisco containing the large subunit Leu-335-Val mutation had a b-value of 13.9±0.7‰. These values were significantly less than that for Rubisco from wild-type tobacco (b=29‰), a C3 species. Transplastomic tobacco producing chimeric Rubisco comprising tobacco Rubisco small subunits and the catalytic large subunits from either the C4 species Flaveria bidentis or the C3-C4 species Flaveria floridana had b-values of 27.8±0.8 and 28.6±0.6‰, respectively. These values were not significantly different from tobacco Rubisco. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.

HNF-1B specifically regulates the transcription of the {gamma}a-subunit of the Na{sup +}/K{sup +}-ATPase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ferre, Silvia; Veenstra, Gert Jan C.; Bouwmeester, Rianne

2011-01-07

Research highlights: {yields} Defects in HNF-1B transcription factor affect Mg{sup 2+} handling in the distal kidney. {yields} {gamma}a- and {gamma}b- subunits of the Na{sup +}/K{sup +}-ATPase colocalize in the distal convoluted tubule of the nephron. {yields} HNF-1B specifically activates {gamma}a expression. {yields} HNF-1B mutants have a dominant negative effect on wild type HNF-1B activity. {yields} Defective transcription of {gamma}a may promote renal Mg{sup 2+} wasting. -- Abstract: Hepatocyte nuclear factor-1B (HNF-1B) is a transcription factor involved in embryonic development and tissue-specific gene expression in several organs, including the kidney. Recently heterozygous mutations in the HNF1B gene have been identified inmore » patients with hypomagnesemia due to renal Mg{sup 2+} wasting. Interestingly, ChIP-chip data revealed HNF-1B binding sites in the FXYD2 gene, encoding the {gamma}-subunit of the Na{sup +}/K{sup +}-ATPase. The {gamma}-subunit has been described as one of the molecular players in the renal Mg{sup 2+} reabsorption in the distal convoluted tubule (DCT). Of note, the FXYD2 gene can be alternatively transcribed into two main variants, namely {gamma}a and {gamma}b. In the present study, we demonstrated via two different reporter gene assays that HNF-1B specifically acts as an activator of the {gamma}a-subunit, whereas the {gamma}b-subunit expression was not affected. Moreover, the HNF-1B mutations H69fsdelAC, H324S325fsdelCA, Y352finsA and K156E, previously identified in patients with hypomagnesemia, prevented transcription activation of {gamma}a-subunit via a dominant negative effect on wild type HNF1-B. By immunohistochemistry, it was shown that the {gamma}a- and {gamma}b-subunits colocalize at the basolateral membrane of the DCT segment of mouse kidney. On the basis of these data, we suggest that abnormalities involving the HNF-1B gene may impair the relative abundance of {gamma}a and {gamma}b, thus affecting the transcellular Mg{sup 2+} reabsorption in the DCT.« less

Serological reactivity of patients with Echinococcus infections (E. granulosus, E. vogeli, and E. multilocularis) against three antigen B subunits.

PubMed

de la Rue, Mário L; Yamano, Kimiaki; Almeida, Cybele E; Iesbich, Margarete P; Fernandes, Cloé D; Goto, Akiko; Kouguchi, Hirokazu; Takahashi, Kenichi

2010-02-01

In serodiagnosis of cystic echinococcosis (CE) by Echinococcus granulosus infection, antigen B (AgB) has been utilized worldwide. However, it is known that about 40% of sera with alveolar echinococcosis (AE) by Echinococcus multilocularis infection recognize AgB. Furthermore, cross-reaction against AgB was also reported in sera from polycystic echinococcosis (PE) patients with Echinococcus vogeli infection. These findings indicate that AgB is widely common to the genus Echinococcus. On the other hand, AgB has several subunits, which are composed of the smallest 8-kDa subunit. In this study, reactivities of patient sera with three kinds of Echinococcus infections (CE, PE, and AE) were compared simultaneously under the same condition against three subunits of AgB (8, 16, and 24 kDa). Many articles have referred the fundamental 8- kDa subunit as a diagnostic antigen for CE. However, the reactivity for the 8-kDa subunit of the CE patient was not so high (47.7%) in this study. Furthermore, there are many cases in which serum of patients with PE or AE also recognizes this subunit (66.7% in PE; 45.9% in AE). AgB is effective for the detection of the genus Echinococcus infections, but it does not have high species specificity. Therefore, we need to pay attention to cross-reaction in serodiagnosis of CE in areas where plural species coexist.

[A study of PDE6B gene mutation and phenotype in Chinese cases with retinitis pigmentosa].

PubMed

Cui, Yun; Zhao, Kan-xing; Wang, Li; Wang, Qing; Zhang, Wei; Chen, Wei-ying; Wang, Li-ming

2003-01-01

To identify the mutation spectrum of phosphodiesterase beta subunit (PDE6B) gene, the incidence in Chinese patients with retinitis pigmentosa (RP) and their clinical phenotypic characteristics. Screening of mutations within PDE6B gene was performed using polymerase chain reaction-heteroduplex-single strand conformation polymorphism (PCR-SSCP) and DNA sequence in 35 autosomal recessive (AR) RP and 55 sporadic RP cases. The phenotypes of the patients with the gene mutation were examined and analyzed. Novel complex heterozygous variants of PDE6B gene in a sporadic case, a T to C transversion in codon 323 resulting in the substitution of Gly by Ser and 2 base pairs (bp: G and T) insert between the 27th-28th bp upstream of the 5'-end of exon 10 were both present in a same isolate RP. But they are not found in 100 unrelated healthy individuals. Ocular findings showed diffuse pigmentary retinal degeneration in the midperipheral and peripheral fundi, optic atrophy and vessel attenuation. Multi-focal ERG indicated that the rod function was more severely deteriorated. A mutation was found in a case with RP in a ARRP family, a G to A transversion at 19th base upstream 5'-end of exon 11 (within intron 10) of PDE6B gene. A sporadic RP carried a sequence variant of PDE6B gene, a G to C transition, at the 15th base adjacent to the 3'-end of exon l8. In another isolate case with RP was found 2 bp (GT) insert between 31st and 32nd base upstream 5'-end of exon 4 (in intron 3) of PDE6B gene. There are novel complex heterozygous mutations of PDE6B gene responsible for a sporadic RP patient in China. This gene mutation associated with rod deterioration and RP. Several DNA variants were found in introns of PDE6B gene in national population.

Effects of SLCO1B1 polymorphisms on the pharmacokinetics and pharmacodynamics of repaglinide in healthy Chinese volunteers.

PubMed

He, Jiake; Qiu, Zhixia; Li, Ning; Yu, Yang; Lu, Yang; Han, Deen; Li, Tingting; Zhao, Di; Sun, Wei; Fang, Fang; Zheng, Jianheng; Fan, Hongwei; Chen, Xijing

2011-07-01

Repaglinide is commonly used in the treatment of patients with type 2 diabetes mellitus to reduce postprandial hyperglycemia. The objective of this research was to study the effects of SLCO1B1 polymorphisms on the pharmacokinetics and pharmacodynamics of repaglinide in healthy Chinese volunteers. A total of 22 healthy young male participants were recruited from a pool of pharmacogenetically characterized participants genotyped for SLCO1B1, CYP3A4, and CYP2C8 SNPs by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Volunteers with CYP2C8*3 and CYP3A4*4 alleles were excluded from the clinical study. Then selected volunteers took part in the clinical pharmacokinetic study, receiving 2 mg repaglinide. Healthy participants with SLCO1B1*1A/*1B or *1A/*1A genotype and SLCO1B1 *15/*1A or *5/*1A genotype had significantly higher AUC(0-∞) than participants with SLCO1B1*1B/*1B genotype, with the former showing an increase over the latter of 39.81 and 42.09%, respectively (P = 0.028, 0.032). The clearance in the former two genotype groups was significantly attenuated (by 27.39 and 28.55%, respectively) compared with individuals with SLCO1B1*1B/*1B genotype (P = 0.015, 0.019). No significant differences in blood glucose-lowering effect were observed among three genotype groups. SLCO1B1*1B/*1B genotype is associated with reduced pharmacokinetic exposure after a single dose oral administration of 2 mg repaglinide, including decreased AUC(0-∞) and increased clearance of repaglinide. Moreover, this polymorphism of SLCO1B1 has significant influence on the pharmacokinetics of repaglinide, but no effects on its pharmacodynamics.

Functional polymorphisms in UDP-glucuronosyltransferases and recurrence in tamoxifen-treated breast cancer survivors

PubMed Central

Ahern, Thomas P.; Christensen, Mariann; Cronin-Fenton, Deirdre P.; Lunetta, Kathryn L.; Søiland, Håvard; Gjerde, Jennifer; Garne, Jens Peter; Rosenberg, Carol L.; Silliman, Rebecca A.; Sørensen, Henrik Toft; Lash, Timothy L.; Hamilton-Dutoit, Stephen

2011-01-01

Background Tamoxifen is oxidized by cytochrome-P450 enzymes (e.g., CYP2D6) to two active metabolites, which are eliminated via glucuronidation by UDP-glucuronosyltransferases (UGTs). We measured the association between functional polymorphisms in key UGTs (UGT2B15*2, UGT2B7*2, and UGT1A8*3) and the recurrence rate among breast cancer survivors. Methods We used the Danish Breast Cancer Cooperative Group registry to identify 541 cases of recurrent breast cancer among women with estrogen receptor-positive tumors treated with tamoxifen for at least one year (ER+/TAM+), and 300 cases of recurrent breast cancer among women with estrogen receptor-negative tumors who were not treated with tamoxifen (ER−/TAM−). We matched 1 control to each case on ER status, menopausal status, stage, calendar period, and county. UGT polymorphisms were genotyped from archived primary tumors. We estimated the recurrence odds ratio for the UGT polymorphisms using logistic regression models, with and without stratification on CYP2D6*4 genotype. Results No UGT polymorphism was associated with breast cancer recurrence in either the ER+/TAM+ or ER-/TAM- groups [in the ER+TAM+ group, compared with two normal alleles: adjusted OR for two UGT2B15*2 variant alleles = 1.0 (95% CI: 0.70, 1.5); adjusted OR for two for UGT2B7*2 variant alleles = 0.91 (95% CI: 0.65, 1.3); adjusted OR for 1 or 2 UGT1A8*3 variant alleles = 0.75 (0.41, 1.4)]. Associations were similar within strata of CYP2D6*4 genotype. Conclusions Functional polymorphisms in key tamoxifen-metabolizing enzymes were not associated with breast cancer recurrence risk. Impact Our results do not support the genotyping of key metabolic enzyme polymorphisms to predict response to tamoxifen therapy. PMID:21750172

Genetic variations in UGT2B28, UGT2B17, UGT2B15 genes and the risk of prostate cancer: A case-control study.

PubMed

Habibi, Mohsen; Mirfakhraie, Reza; Khani, Maryam; Rakhshan, Azadeh; Azargashb, Eznollah; Pouresmaeili, Farkhondeh

2017-11-15

Glucuronidation is a major pathway for elimination of exogenous and endogenous compounds such as environmental carcinogens and androgens from the body. This biochemical pathway is mediated by enzymes called uridine diphosphoglucuronosyltransferases (UGTs). Null (del/del) genes polymorphisms in UGT2B17, and UGT2B28 and D85Y single-nucleotide polymorphism (SNP) of UGT2B15 have been reported to increase the risk of prostate cancer. The goal of this study was to determine the association of mentioned genetic variants with the risk of prostate cancer. We investigated the copy number variations (CNVs) of UGT2B17 and UGT2B28 loci and the association between rs1902023 polymorphism of UGT2B15 gene in 360 subjects consisted of 120 healthy controls, 120 prostate cancer (PC) patients and 120 benign prostatic hyperplasia (BPH) patients. No association was detected for the mentioned polymorphisms and the risk of PC. However, a significant association was detected between UGT2B17 copy number variation and BPH risk (OR=2.189; 95% CI, 1.303-3.675; p=0.003). Furthermore, we observed that the D85Y polymorphism increases the risk of BPH when analyzed in combination with the copy number variation of UGT2B17 gene (OR=0.135; 95% CI, 0.036-0.512; p=0.003). Our findings suggest that the D85Y polymorphism of UGT2B15 and CNVs in UGT2B28 and UGT2B17 genes is not associated with prostate cancer risk in Iranian patients. To our knowledge, this is the first report that implicates the role of CNV of UGT2B17 gene in BPH. Copyright © 2017 Elsevier B.V. All rights reserved.

Effects of CYP3A5, CYP2C19, and CYP2B6 on the clinical efficacy and adverse outcomes of sibutramine therapy: a crucial role for the CYP2B6*6 allele.

PubMed

Hwang, In Cheol; Park, Ji Young; Ahn, Hong Yup; Kim, Kyoung Kon; Suh, Heuy Sun; Ko, Ki Dong; Kim, Kyoung-Ah

2014-01-20

Various cytochrome P450 isoforms modulate sibutramine activity and influence sibutramine plasma levels and pharmacokinetics. However, there are no available data to demonstrate the association of these polymorphisms with the clinical outcomes of sibutramine administration. This study was a sub-investigation of a 12-week, double-blind, placebo-controlled trial examining the additive effect of orlistat on sibutramine. The final analysis was restricted to 101 women who had fulfilled the protocol. We evaluated the effects of genetic polymorphisms of CYP3A5, CYP2C19 and CYP2B6 on the % weight loss and the occurrence of adverse events. The change of pulse rate from baseline value was affected by both CYP2B6 and CYP3A5 genetic polymorphisms (P<.01 for CYP3A5 and P=.01 for CYP2B6). Both CYP2B6 and CYP3A5 showed gene-gene interactions (P<.01). After adjusting for significant variables in the backward stepwise regression model, the change of pulse rate and time-dependent weight reduction were significant only among the CYP2B6 genotypes (P=.027 and P<.01, respectively). The CYP2B6*6 allele influences the extent of weight reduction and pulse rate changes in patients undergoing sibutramine treatment. Copyright © 2013 Elsevier B.V. All rights reserved.

Analysis for complete genomic sequence of HLA-B and HLA-C alleles in the Chinese Han population.

PubMed

Zhu, F; He, Y; Zhang, W; He, J; He, J; Xu, X; Lv, H; Yan, L

2011-08-01

In the present study, we have determined the complete genomic sequence and analysed the intron polymorphism of partial HLA-B and HLA-C alleles in the Chinese Han population. Over 3.0 kb DNA fragments of HLA-B and HLA-C loci were amplified by polymerase chain reaction from partial 5' untranslated region to 3' noncoding region respectively, and then the amplified products were sequenced. Full-length nucleotide sequences of 14 HLA-B alleles and 10 HLA-C alleles were obtained and have been submitted to GenBank and IMGT/HLA database. Two novel alleles of HLA-B*52:01:01:02 and HLA-B*59:01:01:02 were identified, and the complete genomic sequence of HLA-B*52:01:01:01 was firstly reported. Totally 157 and 167 polymorphism positions were found in the full-length genomic sequence of HLA-B and HLA-C loci respectively. Our results suggested that many single nucleotide polymorphisms existed in the exon and intron regions, and the data can provide useful information for understanding the evolution of HLA-B and HLA-C alleles. © 2011 Blackwell Publishing Ltd.

Polymorphisms in exons 1B and 1C of the type I interleukin-1 receptor gene in patients with endometriosis.

PubMed

D'Amora, Paulo; Sato, Hélio; Girão, Manoel J B C; Silva, Ismael D C G; Schor, Eduardo

2006-09-01

To study possible correlation between the prevalence of polymorphisms in the type I interleukin-1 receptor gene and pelvic endometriosis. Genotypes of 223 women were analyzed: 109 women with surgically and histologically confirmed endometriosis and 114 healthy women. Distributions of two single-base polymorphisms of the human interleukin-1 receptor type I (IL-1RI) gene were evaluated: PstI, due to a C-->T transition in exon 1B and BsrBI a C-->A transition at position 52 in exon 1C. Polymorphisms were detected by polymerase chain reaction (PCR) followed by restriction fragment length polymorphism analysis (RFLP) resolved on 3% agarose gels stained with ethidium bromide. Genotypes for PstI polymorphisms did not differ significantly among control and endometriosis (P = 0.058). However, in relation to BsrBI polymorphism, protective risk was observed for the development of endometriosis [OR 0.39-IC 95% (0.2-0.9)]. BsrBI heterozygote genotype (C/A) showed protective effect against endometriosis development.

Drug-related genetic polymorphisms affecting severe chemotherapy-induced neutropenia in breast cancer patients

PubMed Central

Tsuji, Daiki; Ikeda, Midori; Yamamoto, Keisuke; Nakamori, Harumi; Kim, Yong-Il; Kawasaki, Yohei; Otake, Aki; Yokoi, Mari; Inoue, Kazuyuki; Hirai, Keita; Nakamichi, Hidenori; Tokou, Umi; Shiokawa, Mitsuru; Itoh, Kunihiko

2016-01-01

Abstract Chemotherapy-induced neutropenia (CIN) is one of the major adverse events that necessitate chemotherapy dose reduction. This study aimed to evaluate the association between grade 4 neutropenia and genetic polymorphisms in breast cancer patients. In this genetic polymorphism association study, peripheral blood samples from 100 consecutive breast cancer outpatients, between August 2012 and September 2014, treated with doxorubicin and cyclophosphamide (AC) combination chemotherapy were genotyped for polymorphisms in adenosine triphosphate-binding cassette subfamily B member 1 (ABCB1), cytochrome P450 (CYP) enzyme-coding genes (CYP2B6 and CYP3A5), glutathione S-transferase (GST), and excision repair cross-complementing 1 (ERCC1). Associations between grade 4 neutropenia and genotypes as well as risk factors were examined using multivariate logistic regression. From 100 patients, 32.0% had grade 4 neutropenia. Multivariate logistic regression analysis revealed that ERCC1 118C > T (odds ratio [OR], 3.43; 95% confidence interval [CI], 1.22–9.69; P = 0.020), CYP2B6∗6 (OR, 4.51; 95% CI, 1.21–16.95; P = 0.025), body mass index (BMI) (OR, 6.94; 95% CI, 1.15–41.67; P = 0.035), and baseline white blood cell (WBC) count (OR, 2.99; 95% CI, 1.06–8.40; P = 0.038) were significant predictors of grade 4 neutropenia. ERCC1 and CYP2B6 gene polymorphisms were associated with the extent of grade 4 neutropenia in patients receiving AC chemotherapy. In addition to previously known risk factors, BMI and WBC counts, ERCC1 and CYP2B6 gene polymorphisms were also identified as independent strong predictors of grade 4 neutropenia. PMID:27858847

Interaction between caffeine and polymorphisms of glutamate ionotropic receptor NMDA type subunit 2A (GRIN2A) and cytochrome P450 1A2 (CYP1A2) on Parkinson's disease risk.

PubMed

Kim, Iris Y; O'Reilly, Éilis J; Hughes, Katherine C; Gao, Xiang; Schwarzschild, Michael A; McCullough, Marjorie L; Hannan, Marian T; Betensky, Rebecca A; Ascherio, Alberto

2018-03-01

Caffeine intake has been inversely associated with Parkinson's disease (PD) risk. This relationship may be modified by polymorphisms of glutamate ionotropic receptor NMDA type subunit 2A (GRIN2A) and cytochrome P450 1A2 (CYP1A2), but the results of previous studies have been inconsistent. We examined the interaction of caffeine intake with GRIN2A-rs4998386 and CYP1A2-rs762551 polymorphisms in influencing PD risk among 829 incident cases of PD and 2,754 matched controls selected among participants in the following 3 large prospective ongoing cohorts: the Nurses' Health Study, the Health Professionals' Follow-up Study, and the Cancer Prevention Study II Nutrition Cohort. Matching factors included cohort, birth year, source of DNA, date of DNA collection, and race. Relative risks and 95% confidence intervals were estimated using conditional logistic models. Interactions were tested both on the multiplicative scale and on the additive scale. Overall, caffeine intake was associated with a lower PD risk (adjusted relative risk for highest versus lowest tertile = 0.70; 95% confidence interval, 0.57-0.86; p < .001). In analyses stratified by the GRIN2A-rs4998386 genotype, the multivariable-adjusted relative risk of PD comparing the highest to the lowest tertile of caffeine was 0.69 (95% confidence interval, 0.55-0.88; p < .01) among individuals homozygous for the C allele, and 0.85 (95% confidence interval, 0.55-1.32; p = .47; p RERI  = .43) among carriers for the T allele. Interactions between caffeine and GRIN2A were not significant in either the multiplicative or additive scales. We also did not observe significant interactions for CYP1A2-rs762551 and incident PD risk. Our findings do not support the hypothesis of an interaction between the GRIN2A-rs4998386 or CYP1A2-rs762551 polymorphism and caffeine intake in determining PD risk. © 2018 International Parkinson and Movement Disorder Society. © 2018 International Parkinson and Movement Disorder Society.

A Quantitative Analysis of Neurons with Kv3 Potassium Channel Subunits–Kv3.1b and Kv3.2–in Macaque Primary Visual Cortex

PubMed Central

Constantinople, Christine M.; Disney, Anita A; Maffie, Jonathan; Rudy, Bernardo; Hawken, Michael J

2010-01-01

Voltage-gated potassium channels that are composed of Kv3 subunits exhibit distinct electrophysiological properties: activation at more depolarized potentials than other voltage-gated K+ channels and fast kinetics. These channels have been shown to contribute to the high-frequency firing of fast-spiking (FS) GABAergic interneurons in the rat and mouse brain. In the rodent neocortex, there are distinct patterns of expression for the Kv3.1b and Kv3.2 channel subunits and of co-expression of these subunits with neurochemical markers, such as the calcium-binding proteins parvalbumin (PV) and calbindin D-28K (CB). The distribution of Kv3 channels and interrelationship with calcium-binding protein expression has not been investigated in primate cortex. We used immunoperoxidase and immunofluorescent labeling and stereological counting techniques to characterize the laminar and cell-type distributions of Kv3-ir neurons in macaque V1. We found that across the cortical layers ~25% of both Kv3.1b- and Kv3.2-ir neurons are non-GABAergic. In contrast all Kv3-ir neurons in rodent cortex are GABAergic (Chow et al., 1999). The putatively excitatory Kv3-ir neurons were mostly located in layers 2, 3 and 4b. Further, the proportion of Kv3-ir neurons that express PV or CB also differs between macaque V1 and rodent cortex. These data indicate that, within the population of cortical neurons, a broader population of neurons, encompassing cells of a wider range of morphological classes may be capable of sustaining high-frequency firing in macaque V1. PMID:19634181

Absence of correlation between IL-28B gene polymorphisms and the clinical presentation of chronic hepatitis B in an Amazon Brazilian population.

PubMed

Conde, Simone Regina Souza da Silva; Rocha, Luciana L; Ferreira, Vanessa M; Monteiro, Julius Caesar Mendes Soares; Filgueiras, Nathália Karla Fonseca; Lins, Pedro Alves de Almeida; dos Santos, Bruna Tereza Silva; Freitas, Felipe Bonfim; Graça, Ednelza da Silva; Demachki, Sâmia; de Araújo, Marialva Tereza Ferreira; Ishak, Ricardo; Vallinoto, Antonio C R

2014-01-01

The present study investigated the prevalence of the IL-28B polymorphisms rs12979860 and rs8099917 in chronic hepatitis B patients from a case study in Eastern Amazonia. In total, 65 chronically infected HBV patients and 97 healthy subjects who were anti-HBc and anti-HBs positive (control group) were evaluated between May 2011 and December 2012. The groups of patients were designated as inactive carriers, chronic hepatitis without cirrhosis, and chronic hepatitis with cirrhosis based on clinical, pathological, biochemical, hematological, and virological variables. The patients were genotyped using quantitative real-time PCR. The frequencies of the rs12979860 polymorphism were similar between the infected group (32.3% CC, 41.5% CT, and 26.2 TT) and the control population (35% CC, 47.4% CT, and 17.6% TT), and the frequencies of the rs8099917 polymorphism (7.7% GG, 35.4% GT, and 56.9% TT versus 7.2% GG, 35.1% GT, and 57.7% TT) were also similar in both groups. The associations between the rs12979860 and rs8099917 polymorphisms and the clinical manifestations were not statistically significant. In conclusion, these polymorphisms had a similar distribution between infected and control groups, indicating that they were not associated with susceptibility and the clinical evolution of hepatitis B in the examined population.

Neto Auxiliary Protein Interactions Regulate Kainate and NMDA Receptor Subunit Localization at Mossy Fiber–CA3 Pyramidal Cell Synapses

PubMed Central

Wyeth, Megan S.; Pelkey, Kenneth A.; Petralia, Ronald S.; Salter, Michael W.; McInnes, Roderick R.

2014-01-01

Neto1 and Neto2 auxiliary subunits coassemble with NMDA receptors (NMDARs) and kainate receptors (KARs) to modulate their function. In the hippocampus, Neto1 enhances the amplitude and prolongs the kinetics of KAR-mediated currents at mossy fiber (MF)–CA3 pyramidal cell synapses. However, whether Neto1 trafficks KARs to synapses or simply alters channel properties is unresolved. Therefore, postembedding electron microscopy was performed to investigate the localization of GluK2/3 subunits at MF–CA3 synapses in Neto-null mice. Postsynaptic GluK2/3 Immunogold labeling was substantially reduced in Neto-null mice compared with wild types. Moreover, spontaneous KAR-mediated synaptic currents and metabotropic KAR signaling were absent in CA3 pyramidal cells of Neto-null mice. A similar loss of ionotropic and metabotropic KAR function was observed in Neto1, but not Neto2, single knock-out mice, specifically implicating Neto1 in regulating CA3 pyramidal cell KAR localization and function. Additional controversy pertains to the role of Neto proteins in modulating synaptic NMDARs. While Immunogold labeling for GluN2A at MF–CA3 synapses was comparable between wild-type and Neto-null mice, labeling for postsynaptic GluN2B was robustly increased in Neto-null mice. Accordingly, NMDAR-mediated currents at MF–CA3 synapses exhibited increased sensitivity to a GluN2B-selective antagonist in Neto1 knockouts relative to wild types. Thus, despite preservation of the overall MF–CA3 synaptic NMDAR-mediated current, loss of Neto1 alters NMDAR subunit composition. These results confirm that Neto protein interactions regulate synaptic localization of KAR and NMDAR subunits at MF–CA3 synapses, with implications for both ionotropic and metabotropic glutamatergic recruitment of the CA3 network. PMID:24403160

rs3212227 SNP in the IL12B Gene Prevents Delayed Graft Function after Kidney Transplantation.

PubMed

Perovic, Vladimir; Markovic, Milos; Kravljaca, Milica; Milosevic, Emina; Djoric, Milica; Pravica, Vera; Naumovic, Radomir

2018-05-10

Transplantation is the best treatment option for end stage kidney disease. The most common early complications in post-transplant period are acute rejection (AR) of the graft and delayed graft function (DGF). The underlying mechanisms in these events are heterogeneous and at least in part involve cytokine genes which regulate immune response to allograft. We have investigated whether functional single nucleotide polymorphisms (SNP) in the genes encoding IFN-γ (IFNG), TNF (TNFA), IL-10 (IL10) and p40 subunit of IL-12/IL-23 (IL12B) could predict risk of AR and DGF in kidney allograft recipients. Our study involved 152 kidney transplant recipients on standard immunosuppressive regimen which included calcineurin inhibitors, mycophenolic acid derivatives and corticosteroids. Genotyping of IFNG, TNFA, IL10 and IL12B was performed using commercial TaqMan assays. We found association between the carriers of AA genotype of IL12B +1188A/C polymorphism (rs3212227) and a lower rate of DGF (p = 0.037, OR = 0.45, 95% CI = 0.21-0.96), implying protective role of A allele in the pathogenesis of DGF in kidney transplant recipients, whereas no such association was observed with AR. None of the analyzed SNPs in TNFA (-308G/A), IFNG (+874T/A), IL10 (-1082G/A, -819T/C, -592C/A) were associated with AR or DGF in our patients. Our study shows a preliminary evidence that the AA genotype of rs3212227 SNP in the IL12B gene might be associated with a lower risk for DGF after kidney transplantation. In the future, additional well-designed large studies are required for the validation of our results. Copyright © 2018 IMSS. Published by Elsevier Inc. All rights reserved.

A case-control study on association of proteasome subunit beta 8 (PSMB8) and transporter associated with antigen processing 1 (TAP1) polymorphisms and their transcript levels in vitiligo from Gujarat

PubMed Central

Jadeja, Shahnawaz D.; Mansuri, Mohmmad Shoab; Singh, Mala; Dwivedi, Mitesh; Laddha, Naresh C.

2017-01-01

Background Autoimmunity has been implicated in the destruction of melanocytes from vitiligo skin. Major histocompatibility complex (MHC) class-II linked genes proteasome subunit beta 8 (PSMB8) and transporter associated with antigen processing 1 (TAP1), involved in antigen processing and presentation have been reported to be associated with several autoimmune diseases including vitiligo. Objectives To explore PSMB8 rs2071464 and TAP1 rs1135216 single nucleotide polymorphisms and to estimate the expression of PSMB8 and TAP1 in patients with vitiligo and unaffected controls from Gujarat. Methods PSMB8 rs2071464 polymorphism was genotyped using polymerase chain reaction- restriction fragment length polymorphism (PCR-RFLP) and TAP1 rs1135216 polymorphism was genotyped by amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) in 378 patients with vitiligo and 509 controls. Transcript levels of PSMB8 and TAP1 were measured in the PBMCs of 91 patients and 96 controls by using qPCR. Protein levels of PSMB8 were also determined by Western blot analysis. Results The frequency of ‘TT’ genotype of PSMB8 polymorphism was significantly lowered in patients with generalized and active vitiligo (p = 0.019 and p = 0.005) as compared to controls suggesting its association with the activity of the disease. However, TAP1 polymorphism was not associated with vitiligo susceptibility. A significant decrease in expression of PSMB8 at both transcript level (p = 0.002) as well as protein level (p = 0.0460) was observed in vitiligo patients as compared to controls. No significant difference was observed between patients and controls for TAP1 transcripts (p = 0.553). Interestingly, individuals with the susceptible CC genotype of PSMB8 polymorphism showed significantly reduced PSMB8 transcript level as compared to that of CT and TT genotypes (p = 0.009 and p = 0.003 respectively). Conclusions PSMB8 rs2071464 was associated with generalized and active vitiligo from Gujarat whereas TAP1 rs1135216 showed no association. The down-regulation of PSMB8 in patients with risk genotype ‘CC’ advocates the vital role of PSMB8 in the autoimmune basis of vitiligo. PMID:28700671

Crammed signaling motifs in the T-cell receptor.

PubMed

Borroto, Aldo; Abia, David; Alarcón, Balbino

2014-09-01

Although the T cell antigen receptor (TCR) is long known to contain multiple signaling subunits (CD3γ, CD3δ, CD3ɛ and CD3ζ), their role in signal transduction is still not well understood. The presence of at least one immunoreceptor tyrosine-based activation motif (ITAM) in each CD3 subunit has led to the idea that the multiplication of such elements essentially serves to amplify signals. However, the evolutionary conservation of non-ITAM sequences suggests that each CD3 subunit is likely to have specific non-redundant roles at some stage of development or in mature T cell function. The CD3ɛ subunit is paradigmatic because in a relatively short cytoplasmic sequence (∼55 amino acids) it contains several docking sites for proteins involved in intracellular trafficking and signaling, proteins whose relevance in T cell activation is slowly starting to be revealed. In this review we will summarize our current knowledge on the signaling effectors that bind directly to the TCR and we will propose a hierarchy in their response to TCR triggering. Copyright © 2014 Elsevier B.V. All rights reserved.

Phylogeography of Y-chromosome haplogroup O3a2b2-N6 reveals patrilineal traces of Austronesian populations on the eastern coastal regions of Asia

PubMed Central

Teo, Yik-Ying; Huang, Yun-Zhi; Wang, Ling-Xiang; Yu, Ge; Saw, Woei-Yuh; Ong, Rick Twee-Hee; Lu, Yan; Zhang, Chao; Xu, Shu-Hua; Jin, Li; Li, Hui

2017-01-01

Austronesian diffusion is considered one of the greatest dispersals in human history; it led to the peopling of an extremely vast region, ranging from Madagascar in the Indian Ocean to Easter Island in Remote Oceania. The Y-chromosome haplogroup O3a2b*-P164(xM134), a predominant paternal lineage of Austronesian populations, is found at high frequencies in Polynesian populations. However, the internal phylogeny of this haplogroup remains poorly investigated. In this study, we analyzed -seventeen Y-chromosome sequences of haplogroup O3a2b*-P164(xM134) and generated a revised phylogenetic tree of this lineage based on 310 non-private Y-chromosome polymorphisms. We discovered that all available O3a2b*-P164(xM134) samples belong to the newly defined haplogroup O3a2b2-N6 and samples from Austronesian populations belong to the sublineage O3a2b2a2-F706. Additionally, we genotyped a series of Y-chromosome polymorphisms in a large collection of samples from China. We confirmed that the sublineage O3a2b2a2b-B451 is unique to Austronesian populations. We found that O3a2b2-N6 samples are widely distributed on the eastern coastal regions of Asia, from Korea to Vietnam. Furthermore, we propose- that the O3a2b2a2b-B451 lineage represents a genetic connection between ancestors of Austronesian populations and ancient populations in North China, where foxtail millet was domesticated about 11,000 years ago. The large number of newly defined Y-chromosome polymorphisms and the revised phylogenetic tree of O3a2b2-N6 will be helpful to explore the origin of proto-Austronesians and the early diffusion process of Austronesian populations. PMID:28380021

Association of CYP2B6, CYP3A5, and CYP2C19 genetic polymorphisms with sibutramine pharmacokinetics in healthy Korean subjects.

PubMed

Kim, K A; Song, W K; Park, J Y

2009-11-01

We assessed the association of CYP2B6, CYP3A5, and CYP2C19 polymorphisms with sibutramine pharmacokinetics. Forty six healthy male subjects were enrolled, and their CYP2B6 (*4 and *6), CYP3A5 (*3), and CYP2C19 (*2, and *3) genotypes were analyzed. After a single 15-mg dose of sibutramine was administered, plasma concentrations of sibutramine and its metabolites, M1 and M2, were measured. CYP2B6 and CYP3A5 polymorphisms did not affect the pharmacokinetics of sibutramine and its metabolites. However, the CYP2C19 genotype substantially influenced plasma levels of sibutramine and its metabolites. The mean area under the curve (AUC) of sibutramine in CYP2C19 intermediate metabolizers (IMs; *1/*2 or *1/*3) and poor metabolizers (PMs; *2/*2, *2/*3)) was 18.5 and 252.2% higher, respectively, than the AUC in extensive metabolizers (EMs, *1/*1) (P < 0.001). The AUC of M1 metabolite in IMs and PMs was 22.5 and 148.0% higher, respectively, than that of EMs (P < 0.001). Our findings indicate that the CYP2C19 genotype substantially affects the pharmacokinetics of sibutramine.

The delta-subunit of murine guanine nucleotide exchange factor eIF-2B. Characterization of cDNAs predicts isoforms differing at the amino-terminal end.

PubMed

Henderson, R A; Krissansen, G W; Yong, R Y; Leung, E; Watson, J D; Dholakia, J N

1994-12-02

Protein synthesis in mammalian cells is regulated at the level of the guanine nucleotide exchange factor, eIF-2B, which catalyzes the exchange of eukaryotic initiation factor 2-bound GDP for GTP. We have isolated and sequenced cDNA clones encoding the delta-subunit of murine eIF-2B. The cDNA sequence encodes a polypeptide of 544 amino acids with molecular mass of 60 kDa. Antibodies against a synthetic polypeptide of 30 amino acids deduced from the cDNA sequence specifically react with the delta-subunit of mammalian eIF-2B. The cDNA-derived amino acid sequence shows significant homology with the yeast translational regulator Gcd2, supporting the hypothesis that Gcd2 may be the yeast homolog of the delta-subunit of mammalian eIF-2B. Primer extension studies and anchor polymerase chain reaction analysis were performed to determine the 5'-end of the transcript for the delta-subunit of eIF-2B. Results of these experiments demonstrate two different mRNAs for the delta-subunit of eIF-2B in murine cells. The isolation and characterization of two different full-length cDNAs also predicts the presence of two alternate forms of the delta-subunit of eIF-2B in murine cells. These differ at their amino-terminal end but have identical nucleotide sequences coding for amino acids 31-544.

Comparisons of Native Shiga Toxins (Stxs) Type 1 and 2 with Chimeric Toxins Indicate that the Source of the Binding Subunit Dictates Degree of Toxicity

PubMed Central

Russo, Lisa M.; Melton-Celsa, Angela R.; Smith, Michael J.; O'Brien, Alison D.

2014-01-01

Shiga toxin (Stx)-producing E. coli (STEC) cause food-borne outbreaks of hemorrhagic colitis. The main virulence factor expressed by STEC, Stx, is an AB5 toxin that has two antigenically distinct forms, Stx1a and Stx2a. Although Stx1a and Stx2a bind to the same receptor, globotriaosylceramide (Gb3), Stx2a is more potent than Stx1a in mice, whereas Stx1a is more cytotoxic than Stx2a in cell culture. In this study, we used chimeric toxins to ask what the relative contribution of individual Stx subunits is to the differential toxicity of Stx1a and Stx2a in vitro and in vivo. Chimeric stx1/stx2 operons were generated by PCR such that the coding regions for the A2 and B subunits of one toxin were combined with the coding region for the A1 subunit of the heterologous toxin. The toxicities of purified Stx1a, Stx2a, and the chimeric Stxs were determined on Vero and HCT-8 cell lines, while polarized HCT-8 cell monolayers grown on permeable supports were used to follow toxin translocation. In all in vitro assays, the activity of the chimeric toxin correlated with that of the parental toxin from which the B subunit originated. The origin of the native B subunit also dictated the 50% lethal dose of toxin after intraperitoneal intoxication of mice; however, the chimeric Stxs exhibited reduced oral toxicity and pH stability compared to Stx1a and Stx2a. Taken together, these data support the hypothesis that the differential toxicity of the chimeric toxins for cells and mice is determined by the origin of the B subunit. PMID:24671194

PCR cloning and characterization of multiple ADP-glucose pyrophosphorylase cDNAs from tomato

NASA Technical Reports Server (NTRS)

Chen, B. Y.; Janes, H. W.; Gianfagna, T.

1998-01-01

Four ADP-glucose pyrophosphorylase (AGP) cDNAs were cloned from tomato fruit and leaves by the PCR techniques. Three of them (agp S1, agp S2, and agp S3) encode the large subunit of AGP, the fourth one (agp B) encodes the small subunit. The deduced amino acid sequences of the cDNAs show very high identities (96-98%) to the corresponding potato AGP isoforms, although there are major differences in tissue expression profiles. All four tomato AGP transcripts were detected in fruit and leaves; the predominant ones in fruit are agp B and agp S1, whereas in leaves they are agp B and agp S3. Genomic southern analysis suggests that the four AGP transcripts are encoded by distinct genes.

Quechua Amerindian population characterized by HLA-DQ alpha, YNZ22, 3'APO B, HUMTH01, and HUMVWA31A polymorphisms.

PubMed

Gené, M; Fuentes, M; Huguet, E; Piqué, E; Bert, F; Corella, A; Pérez-Pérez, A; Corbella, J; Moreno, P

1998-03-01

Allele and genotype frequencies of DNA polymorphisms were determined in a population sample of Quechua (n = 113) using the polymerase chain reaction (PCR). We report data on the frequencies of HLA-DQ alpha, YNZ22, 3'ApoB, HUMTH01 and HUMVWA31A alleles and the distribution of the different genotypes. No significant deviations between observed and expected numbers were found, thus assuming the Hardy-Weinberg equilibrium.

Retrograde and transganglionic transport of horseradish peroxidase-conjugated cholera toxin B subunit, wheatgerm agglutinin and isolectin B4 from Griffonia simplicifolia I in primary afferent neurons innervating the rat urinary bladder.

PubMed

Wang, H F; Shortland, P; Park, M J; Grant, G

1998-11-01

In the present study, we investigated and compared the ability of the cholera toxin B subunit, wheat germ agglutinin and isolectin B4 from Griffonia simplicifolia I conjugated to horseradish peroxidase, to retrogradely and transganglionically label visceral primary afferents after unilateral injections into the rat urinary bladder wall. Horseradish peroxidase histochemical or lectin-immunofluorescence histochemical labelling of bladder afferents was seen in the L6-S1 spinal cord segments and in the T13-L2 and L6-S1 dorsal root ganglia. In the lumbosacral spinal cord, the most intense and extensive labelling of bladder afferents was seen when cholera toxin B subunit-horseradish peroxidase was injected. Cholera toxin B subunit-horseradish peroxidase-labelled fibres were found in Lissauer's tract, its lateral and medial collateral projections, and laminae I and IV-VI of the spinal gray matter. Labelled fibres were numerous in the lateral collateral projection and extended into the spinal parasympathetic nucleus. Labelling from both the lateral and medial projections extended into the dorsal grey commissural region. Wheat germ agglutinin-horseradish peroxidase labelling produced a similar pattern but was not as dense and extensive as that of cholera toxin B subunit-horseradish peroxidase. The isolectin B4 from Griffonia simplicifolia I-horseradish peroxidase-labelled fibres, on the other hand, were fewer and only observed in the lateral collateral projection and occasionally in lamina I. Cell profile counts showed that a larger number of dorsal root ganglion cells were labelled with cholera toxin B subunit-horseradish peroxidase than with wheat germ agglutinin- or isolectin B4-horseradish peroxidase. In the L6-S1 dorsal root ganglia, the majority (81%) of the cholera toxin B subunit-, and almost all of the wheat germ agglutinin- and isolectin B4-immunoreactive cells were RT97-negative (an anti-neurofilament antibody that labels dorsal root ganglion neurons with myelinated fibres). Double labelling with other neuronal markers showed that 71%, 43% and 36% of the cholera toxin B subunit-immunoreactive cells were calcitonin gene-related peptide-, isolectin B4-binding- and substance P-positive, respectively. A few cholera toxin B subunit cells showed galanin-immunoreactivity, but none were somatostatin-, vasoactive intestinal polypeptide-, or neuropeptide Y-immunoreactive or contained fluoride-resistant acid phosphatase. The results show that cholera toxin B subunit-horseradish peroxidase is a more effective retrograde and transganglionic tracer for pelvic primary afferents from the urinary bladder than wheat germ agglutinin-horseradish peroxidase and isolectin B4-horseradish peroxidase, but in contrast to somatic nerves, it is transported mainly by unmyelinated fibres in the visceral afferents.

Gap compression/extension mechanism of bacterial flagellar hook as the molecular universal joint.

PubMed

Furuta, Tadaomi; Samatey, Fadel A; Matsunami, Hideyuki; Imada, Katsumi; Namba, Keiichi; Kitao, Akio

2007-03-01

Bacterial flagellar hook acts as a molecular universal joint, transmitting torque produced by the flagellar basal body, a rotary motor, to the flagellar filament. The hook forms polymorphic supercoil structures and can be considered as an assembly of 11 circularly arranged protofilaments. We investigated the molecular mechanism of the universal joint function of the hook by a approximately two-million-atom molecular dynamics simulation. On the inner side of the supercoil, protein subunits are highly packed along the protofilament and no gaps remain for further compression, whereas subunits are slightly separated and are hydrogen bonded through one layer of water molecules on the outer side. As for the intersubunit interactions between protofilaments, subunits are packed along the 6-start helix in a left-handed supercoil whereas they are highly packed along the 5-start helix in a right-handed supercoil. We conclude that the supercoiled structures of the hook in the left- and right-handed forms make maximal use of the gaps between subunits, which we call "gap compression/extension mechanism". Mutual sliding of subunits at the subunit interface accompanying rearrangements of intersubunit hydrogen bonds is interpreted as a mechanism to allow continuous structural change of the hook during flagellar rotation at low energy cost.

Polymorphisms of drug-metabolizing enzymes (GST, CYP2B6 and CYP3A) affect the pharmacokinetics of thiotepa and tepa

PubMed Central

Ekhart, Corine; Doodeman, Valerie D; Rodenhuis, Sjoerd; Smits, Paul H M; Beijnen, Jos H; Huitema, Alwin D R

2009-01-01

AIMS Thiotepa is widely used in high-dose chemotherapy. Previous studies have shown relations between exposure and severe organ toxicity. Thiotepa is metabolized by cytochrome P450 and glutathione S-transferase enzymes. Polymorphisms of these enzymes may affect elimination of thiotepa and tepa, its main metabolite. The purpose of this study was to evaluate effects of known allelic variants in CYP2B6, CYP3A4, CYP3A5, GSTA1 and GSTP1 genes on pharmacokinetics of thiotepa and tepa. METHODS White patients (n = 124) received a high-dose regimen consisting of cyclophosphamide, thiotepa and carboplatin as intravenous infusions. Genomic DNA was analysed using polymerase chain reaction and sequencing. Plasma concentrations of thiotepa and tepa were determined using validated GC and LC-MS/MS methods. Relations between allelic variants and elimination pharmacokinetic parameters were evaluated using nonlinear mixed effects modelling (nonmem). RESULTS The polymorphisms CYP2B6 C1459T, CYP3A4*1B, CYP3A5*3, GSTA1 (C-69T, G-52A) and GSTP1 C341T had a significant effect on clearance of thiotepa or tepa. Although significant, most effects were generally not large. Clearance of thiotepa and tepa was predominantly affected by GSTP1 C341T polymorphism, which had a frequency of 9.3%. This polymorphism increased non-inducible thiotepa clearance by 52% [95% confidence interval (CI) 41, 64, P < 0.001] and decreased tepa clearance by 32% (95% CI 29, 35, P < 0.001) in heterozygous patients, which resulted in an increase in combined exposure to thiotepa and tepa of 45% in homozygous patients. CONCLUSIONS This study indicates that the presently evaluated variant alleles explain only a small part of the substantial interindividual variability in thiotepa and tepa pharmacokinetics. Patients homozygous for the GSTP1 C341T allele may have enhanced exposure to thiotepa and tepa. PMID:19076156

The Respiratory Arsenite Oxidase: Structure and the Role of Residues Surrounding the Rieske Cluster

PubMed Central

Warelow, Thomas P.; Oke, Muse; Schoepp-Cothenet, Barbara; Dahl, Jan U.; Bruselat, Nicole; Sivalingam, Ganesh N.; Leimkühler, Silke; Thalassinos, Konstantinos; Kappler, Ulrike; Naismith, James H.; Santini, Joanne M.

2013-01-01

The arsenite oxidase (Aio) from the facultative autotrophic Alphaproteobacterium Rhizobium sp. NT-26 is a bioenergetic enzyme involved in the oxidation of arsenite to arsenate. The enzyme from the distantly related heterotroph, Alcaligenes faecalis, which is thought to oxidise arsenite for detoxification, consists of a large α subunit (AioA) with bis-molybdopterin guanine dinucleotide at its active site and a 3Fe-4S cluster, and a small β subunit (AioB) which contains a Rieske 2Fe-2S cluster. The successful heterologous expression of the NT-26 Aio in Escherichia coli has resulted in the solution of its crystal structure. The NT-26 Aio, a heterotetramer, shares high overall similarity to the heterodimeric arsenite oxidase from A. faecalis but there are striking differences in the structure surrounding the Rieske 2Fe-2S cluster which we demonstrate explains the difference in the observed redox potentials (+225 mV vs. +130/160 mV, respectively). A combination of site-directed mutagenesis and electron paramagnetic resonance was used to explore the differences observed in the structure and redox properties of the Rieske cluster. In the NT-26 AioB the substitution of a serine (S126 in NT-26) for a threonine as in the A. faecalis AioB explains a −20 mV decrease in redox potential. The disulphide bridge in the A. faecalis AioB which is conserved in other betaproteobacterial AioB subunits and the Rieske subunit of the cytochrome bc 1 complex is absent in the NT-26 AioB subunit. The introduction of a disulphide bridge had no effect on Aio activity or protein stability but resulted in a decrease in the redox potential of the cluster. These results are in conflict with previous data on the betaproteobacterial AioB subunit and the Rieske of the bc 1 complex where removal of the disulphide bridge had no effect on the redox potential of the former but a decrease in cluster stability was observed in the latter. PMID:24023621

Genetic map of Triticum turgidum based on a hexaploid wheat population without genetic recombination for D genome.

PubMed

Zhang, Li; Luo, Jiang-Tao; Hao, Ming; Zhang, Lian-Quan; Yuan, Zhong-Wei; Yan, Ze-Hong; Liu, Ya-Xi; Zhang, Bo; Liu, Bao-Long; Liu, Chun-Ji; Zhang, Huai-Gang; Zheng, You-Liang; Liu, Deng-Cai

2012-08-13

A synthetic doubled-haploid hexaploid wheat population, SynDH1, derived from the spontaneous chromosome doubling of triploid F1 hybrid plants obtained from the cross of hybrids Triticum turgidum ssp. durum line Langdon (LDN) and ssp. turgidum line AS313, with Aegilops tauschii ssp. tauschii accession AS60, was previously constructed. SynDH1 is a tetraploidization-hexaploid doubled haploid (DH) population because it contains recombinant A and B chromosomes from two different T. turgidum genotypes, while all the D chromosomes from Ae. tauschii are homogenous across the whole population. This paper reports the construction of a genetic map using this population. Of the 606 markers used to assemble the genetic map, 588 (97%) were assigned to linkage groups. These included 513 Diversity Arrays Technology (DArT) markers, 72 simple sequence repeat (SSR), one insertion site-based polymorphism (ISBP), and two high-molecular-weight glutenin subunit (HMW-GS) markers. These markers were assigned to the 14 chromosomes, covering 2048.79 cM, with a mean distance of 3.48 cM between adjacent markers. This map showed good coverage of the A and B genome chromosomes, apart from 3A, 5A, 6A, and 4B. Compared with previously reported maps, most shared markers showed highly consistent orders. This map was successfully used to identify five quantitative trait loci (QTL), including two for spikelet number on chromosomes 7A and 5B, two for spike length on 7A and 3B, and one for 1000-grain weight on 4B. However, differences in crossability QTL between the two T. turgidum parents may explain the segregation distortion regions on chromosomes 1A, 3B, and 6B. A genetic map of T. turgidum including 588 markers was constructed using a synthetic doubled haploid (SynDH) hexaploid wheat population. Five QTLs for three agronomic traits were identified from this population. However, more markers are needed to increase the density and resolution of this map in the future study.

Polymorphisms in Arsenic(+III Oxidation State) Methyltransferase (AS3MT) Predict Gene Expression of AS3MT as Well as Arsenic Metabolism

PubMed Central

Engström, Karin; Vahter, Marie; Mlakar, Simona Jurkovic; Concha, Gabriela; Nermell, Barbro; Raqib, Rubhana; Cardozo, Alejandro; Broberg, Karin

2011-01-01

Background Arsenic (As) occurs as monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA) in humans, and the methylation pattern demonstrates large interindividual differences. The fraction of urinary MMA is a marker for susceptibility to As-related diseases. Objectives We evaluated the impact of polymorphisms in five methyltransferase genes on As metabolism in two populations, one in South America and one in Southeast Asia. The methyltransferase genes were arsenic(+III oxidation state) methyltransferase (AS3MT), DNA-methyltransferase 1a and 3b (DNMT1a and DNMT3b, respectively), phosphatidylethanolamine N-methyltransferase (PEMT), and betaine-homocysteine methyltransferase (BHMT). AS3MT expression was analyzed in peripheral blood. Methods Subjects were women exposed to As in drinking water in the Argentinean Andes [n = 172; median total urinary As (U-As), 200 μg/L] and in rural Bangladesh (n = 361; U-As, 100 μg/L; all in early pregnancy). Urinary As metabolites were measured by high-pressure liquid chromatography/inductively coupled plasma mass spectrometry. Polymorphisms (n = 22) were genotyped with Sequenom, and AS3MT expression was measured by quantitative real-time polymerase chain reaction using TaqMan expression assays. Results Six AS3MT polymorphisms were significantly associated with As metabolite patterns in both populations (p ≤ 0.01). The most frequent AS3MT haplotype in Bangladesh was associated with a higher percentage of MMA (%MMA), and the most frequent haplotype in Argentina was associated with a lower %MMA and a higher percentage of DMA. Four polymorphisms in the DNMT genes were associated with metabolite patterns in Bangladesh. Noncoding AS3MT polymorphisms affected gene expression of AS3MT in peripheral blood, demonstrating that one functional impact of AS3MT polymorphisms may be altered levels of gene expression. Conclusions Polymorphisms in AS3MT significantly predicted As metabolism across these two very different populations, suggesting that AS3MT may have an impact on As metabolite patterns in populations worldwide. PMID:21247820

Spatial distribution of single-nucleotide polymorphisms related to fungicide resistance and implications for sampling.

PubMed

Van der Heyden, H; Dutilleul, P; Brodeur, L; Carisse, O

2014-06-01

Spatial distribution of single-nucleotide polymorphisms (SNPs) related to fungicide resistance was studied for Botrytis cinerea populations in vineyards and for B. squamosa populations in onion fields. Heterogeneity in this distribution was characterized by performing geostatistical analyses based on semivariograms and through the fitting of discrete probability distributions. Two SNPs known to be responsible for boscalid resistance (H272R and H272Y), both located on the B subunit of the succinate dehydrogenase gene, and one SNP known to be responsible for dicarboximide resistance (I365S) were chosen for B. cinerea in grape. For B. squamosa in onion, one SNP responsible for dicarboximide resistance (I365S homologous) was chosen. One onion field was sampled in 2009 and another one was sampled in 2010 for B. squamosa, and two vineyards were sampled in 2011 for B. cinerea, for a total of four sampled sites. Cluster sampling was carried on a 10-by-10 grid, each of the 100 nodes being the center of a 10-by-10-m quadrat. In each quadrat, 10 samples were collected and analyzed by restriction fragment length polymorphism polymerase chain reaction (PCR) or allele specific PCR. Mean SNP incidence varied from 16 to 68%, with an overall mean incidence of 43%. In the geostatistical analyses, omnidirectional variograms showed spatial autocorrelation characterized by ranges of 21 to 1 m. Various levels of anisotropy were detected, however, with variograms computed in four directions (at 0°, 45°, 90°, and 135° from the within-row direction used as reference), indicating that spatial autocorrelation was prevalent or characterized by a longer range in one direction. For all eight data sets, the β-binomial distribution was found to fit the data better than the binomial distribution. This indicates local aggregation of fungicide resistance among sampling units, as supported by estimates of the parameter θ of the β-binomial distribution of 0.09 to 0.23 (overall median value = 0.20). On the basis of the observed spatial distribution patterns of SNP incidence, sampling curves were computed for different levels of reliability, emphasizing the importance of sample size for the detection of mutation incidence below the risk threshold for control failure.

Functional Analysis of a Wheat AGPase Plastidial Small Subunit with a Truncated Transit Peptide.

PubMed

Yang, Yang; Gao, Tian; Xu, Mengjun; Dong, Jie; Li, Hanxiao; Wang, Pengfei; Li, Gezi; Guo, Tiancai; Kang, Guozhang; Wang, Yonghua

2017-03-01

ADP-glucose pyrophosphorylase (AGPase), the key enzyme in starch synthesis, consists of two small subunits and two large subunits with cytosolic and plastidial isoforms. In our previous study, a cDNA sequence encoding the plastidial small subunit (TaAGPS1b) of AGPase in grains of bread wheat ( Triticum aestivum L.) was isolated and the protein subunit encoded by this gene was characterized as a truncated transit peptide (about 50% shorter than those of other plant AGPS1bs). In the present study, TaAGPS1b was fused with green fluorescent protein (GFP) in rice protoplast cells, and confocal fluorescence microscopy observations revealed that like other AGPS1b containing the normal transit peptide, TaAGPS1b-GFP was localized in chloroplasts. TaAGPS1b was further overexpressed in a Chinese bread wheat cultivar, and the transgenic wheat lines exhibited a significant increase in endosperm AGPase activities, starch contents, and grain weights. These suggested that TaAGPS1b subunit was targeted into plastids by its truncated transit peptide and it could play an important role in starch synthesis in bread wheat grains.

Multiplex Droplet Digital PCR Quantification of Recurrent Somatic Mutations in Diffuse Large B-Cell and Follicular Lymphoma.

PubMed

Alcaide, Miguel; Yu, Stephen; Bushell, Kevin; Fornika, Daniel; Nielsen, Julie S; Nelson, Brad H; Mann, Koren K; Assouline, Sarit; Johnson, Nathalie A; Morin, Ryan D

2016-09-01

A plethora of options to detect mutations in tumor-derived DNA currently exist but each suffers limitations in analytical sensitivity, cost, or scalability. Droplet digital PCR (ddPCR) is an appealing technology for detecting the presence of specific mutations based on a priori knowledge and can be applied to tumor biopsies, including formalin-fixed paraffin embedded (FFPE) tissues. More recently, ddPCR has gained popularity in its utility in quantifying circulating tumor DNA. We have developed a suite of novel ddPCR assays for detecting recurrent mutations that are prevalent in common B-cell non-Hodgkin lymphomas (NHLs), including diffuse large B-cell lymphoma, follicular lymphoma, and lymphoplasmacytic lymphoma. These assays allowed the differentiation and counting of mutant and wild-type molecules using one single hydrolysis probe. We also implemented multiplexing that allowed the simultaneous detection of distinct mutations and an "inverted" ddPCR assay design, based on employing probes matching wild-type alleles, capable of detecting the presence of multiple single nucleotide polymorphisms. The assays successfully detected and quantified somatic mutations commonly affecting enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2) (Y641) and signal transducer and activator of transcription 6 (STAT6) (D419) hotspots in fresh tumor, FFPE, and liquid biopsies. The "inverted" ddPCR approach effectively reported any single nucleotide variant affecting either of these 2 hotspots as well. Finally, we could effectively multiplex hydrolysis probes targeting 2 additional lymphoma-related hotspots: myeloid differentiation primary response 88 (MYD88; L265P) and cyclin D3 (CCND3; I290R). Our suite of ddPCR assays provides sufficient analytical sensitivity and specificity for either the invasive or noninvasive detection of multiple recurrent somatic mutations in B-cell NHLs. © 2016 American Association for Clinical Chemistry.

[Genetic polymorphisms of ARL15 and HLA-DMA are associated with rheumatoid arthritis in Han population from northwest China].

PubMed

Wang, Jiao; Qi, Xiaoming; Zhang, Xiaozhen; Yan, Wen; You, Chongge

2017-12-01

Objective To establish the methods for detecting single nucleotide polymorphisms (SNPs) of ADP-ribosylation factor-like GTPase 15 (ARL15), major histocompatibility complex class II-DM alpha (HLA-DMA ) and nuclear factor kappa B subunit 2 (NFKB2) genes using high resolution melting (HRM) technology, and to explore the association of those SNPs with the susceptibility of rheumatoid arthritis (RA) in northwestern Han Chinese population. Methods The PCR-HRM detection system for four SNPs (rs255758, rs1063478, rs397514331 and rs397514332) was established for genotyping, and gene sequencing was performed to validate the genotyping ability of the system. 588 RA cases and 200 controls were enrolled in a case-control study to analyze the associations of ARL15 and HLA-DMA gene polymorphisms with RA risk. Results The direct sequencing validated that the established PCR-HRM detection system could be used for genotyping clinical samples correctly. The mutated genotype of rs397514331 and rs397514332 from NFKB2 gene are not found in this study. The genotype frequencies of rs255758 and rs1063478 had statistical difference between the cases and controls, but no statistical difference in allelic frequencies. Under the dominant model (AA vs AC/CC), the AA genotype of rs255758 decreases the RA risk (OR=0.666, 95%CI=0.478-0.927, P=0.016). Conclusion The method of PCR-HRM we established can be applied to the routine detection of rs255758, rs1063478, rs397514331 and rs397514332. The ARL15 and HLA-DMA gene polymorphisms are associated with RA risk in Northwestern Han Chinese population.

The nicotinic acetylcholine receptor gene family of the silkworm, Bombyx mori

PubMed Central

Shao, Ya-Ming; Dong, Ke; Zhang, Chuan-Xi

2007-01-01

Background Nicotinic acetylcholine receptors (nAChRs) mediate fast synaptic cholinergic transmission in the insect central nervous system. The insect nAChR is the molecular target of a class of insecticides, neonicotinoids. Like mammalian nAChRs, insect nAChRs are considered to be made up of five subunits, coded by homologous genes belonging to the same family. The nAChR subunit genes of Drosophila melanogaster, Apis mellifera and Anopheles gambiae have been cloned previously based on their genome sequences. The silkworm Bombyx mori is a model insect of Lepidoptera, among which are many agricultural pests. Identification and characterization of B. mori nAChR genes could provide valuable basic information for this important family of receptor genes and for the study of the molecular mechanisms of neonicotinoid action and resistance. Results We searched the genome sequence database of B. mori with the fruit fly and honeybee nAChRs by tBlastn and cloned all putative silkworm nAChR cDNAs by reverse transcriptase-polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE) methods. B. mori appears to have the largest known insect nAChR gene family to date, including nine α-type subunits and three β-type subunits. The silkworm possesses three genes having low identity with others, including one α and two β subunits, α9, β2 and β3. Like the fruit fly and honeybee counterparts, silkworm nAChR gene α6 has RNA-editing sites, and α4, α6 and α8 undergo alternative splicing. In particular, alternative exon 7 of Bmα8 may have arisen from a recent duplication event. Truncated transcripts were found for Bmα4 and Bmα5. Conclusion B. mori possesses a largest known insect nAChR gene family characterized to date, including nine α-type subunits and three β-type subunits. RNA-editing, alternative splicing and truncated transcripts were found in several subunit genes, which might enhance the diversity of the gene family. PMID:17868469

The Val192Leu mutation in the alpha-subunit of beta-hexosaminidase A is not associated with the B1-variant form of Tay-Sachs disease.

PubMed Central

Hou, Y.; Vavougios, G.; Hinek, A.; Wu, K. K.; Hechtman, P.; Kaplan, F.; Mahuran, D. J.

1996-01-01

Substitution mutations adversely affecting the alpha-subunit of beta-hexosaminidase A (alphabeta) (EC 3.2.1.52) result in Tay-Sachs disease. The majority affect the initial folding of the pro-alpha chain in the endoplasmic reticulum, resulting in its retention and degradation. A much less common occurrence is a mutation that specifically affects an "active-site" residue necessary for substrate binding and/or catalysis. In this case, hexosaminidase A is present in the lysosome, but it lacks all alpha-specific activity. This biochemical phenotype is referred to as the "B1-variant form" of Tay-Sachs disease. Kinetic analysis of suspected B1-variant mutations is complex because hexosaminidase A is heterodimeric and both subunits possess similar active sites. In this report, we examine a previously identified B1-variant mutation, alpha-Val192Leu. Chinese hamster ovary cells were permanently cotransfected with an alpha-cDNA-construct encoding the substitution and a mutant beta-cDNA (beta-Arg211Lys), encoding a beta-subunit that is inactive but normal in all other respects. We were surprised to find that the Val192Leu substitution, produced a pro-alpha chain that did not form alpha-beta dimers and was not transported to the lysosome. Finally, we reexamined the hexosaminidase activity and protein levels in the fibroblasts from the original patient. These data were also not consistent with the biochemical phenotype of the B1 variant of Tay-Sachs disease previously reported to be present. Thus, we conclude that the Val192Leu substitution does not specifically affect the alpha-active site. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:8659543

A comprehensive experiment for molecular biology: Determination of single nucleotide polymorphism in human REV3 gene using PCR-RFLP.

PubMed

Zhang, Xu; Shao, Meng; Gao, Lu; Zhao, Yuanyuan; Sun, Zixuan; Zhou, Liping; Yan, Yongmin; Shao, Qixiang; Xu, Wenrong; Qian, Hui

2017-07-08

Laboratory exercise is helpful for medical students to understand the basic principles of molecular biology and to learn about the practical applications of molecular biology. We have designed a lab course on molecular biology about the determination of single nucleotide polymorphism (SNP) in human REV3 gene, the product of which is a subunit of DNA polymerase ζ and SNPs in this gene are associated with altered susceptibility to cancer. This newly designed experiment is composed of three parts, including genomic DNA extraction, gene amplification by PCR, and genotyping by RFLP. By combining these activities, the students are not only able to learn a series of biotechniques in molecular biology, but also acquire the ability to link the learned knowledge with practical applications. This comprehensive experiment will help the medical students improve the conceptual understanding of SNP and the technical understanding of SNP detection. © 2017 by The International Union of Biochemistry and Molecular Biology, 45(4):299-304, 2017. © 2017 The International Union of Biochemistry and Molecular Biology.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spreitzer, Robert J.

CO{sub 2} and O{sub 2} are mutually competitive at the active site of ribulose-1,5-biphosphate (RuBP) carboxylase/oxygenase (Rubisco). Rubisco contains two subunits, each present in eight copies. The 15-kD small subunit is coded by a family of nuclear RbcS genes. Until now, the role of the small subunit in Rubisco structure or catalytic efficiency is not known. Because of other work in eliminating the two RbcS genes in the green algo Chlamydomonas reinhardtii, it is now possible to address questions about the structure-function relationships of the eukaryotic small subunit. There are three specific aims in this project: (1) Alanine scanning mutagenesismore » is being used to dissect the importance of the {beta}A/{beta}B loop, a feature unique to the eukaryotic small subunit. (2) Random mutagenesis is being used to identify additional residues or regions of the small subunit that are important for holoenzyme assembly and function. (3) Attempts are being made to express foreign small subunits in Chlamydomonas to examine the contribution of small subunits to holoenzyme assembly, catalytic efficiency, and CO{sub 2}/O{sub 2} specificity.« less

The HOOK region of voltage-gated Ca2+ channel β subunits senses and transmits PIP2 signals to the gate.

PubMed

Park, Cheon-Gyu; Park, Yongsoo; Suh, Byung-Chang

2017-02-01

The β subunit of voltage-gated Ca 2+ (Ca V ) channels plays an important role in regulating gating of the α1 pore-forming subunit and its regulation by phosphatidylinositol 4,5-bisphosphate (PIP 2 ). Subcellular localization of the Ca V β subunit is critical for this effect; N-terminal-dependent membrane targeting of the β subunit slows inactivation and decreases PIP 2 sensitivity. Here, we provide evidence that the HOOK region of the β subunit plays an important role in the regulation of Ca V biophysics. Based on amino acid composition, we broadly divide the HOOK region into three domains: S (polyserine), A (polyacidic), and B (polybasic). We show that a β subunit containing only its A domain in the HOOK region increases inactivation kinetics and channel inhibition by PIP 2 depletion, whereas a β subunit with only a B domain decreases these responses. When both the A and B domains are deleted, or when the entire HOOK region is deleted, the responses are elevated. Using a peptide-to-liposome binding assay and confocal microscopy, we find that the B domain of the HOOK region directly interacts with anionic phospholipids via polybasic and two hydrophobic Phe residues. The β2c-short subunit, which lacks an A domain and contains fewer basic amino acids and no Phe residues in the B domain, neither associates with phospholipids nor affects channel gating dynamically. Together, our data suggest that the flexible HOOK region of the β subunit acts as an important regulator of Ca V channel gating via dynamic electrostatic and hydrophobic interaction with the plasma membrane. © 2017 Park et al.

Structure–function analysis and genetic interactions of the SmG, SmE, and SmF subunits of the yeast Sm protein ring

PubMed Central

Schwer, Beate; Kruchten, Joshua; Shuman, Stewart

2016-01-01

A seven-subunit Sm protein ring forms a core scaffold of the U1, U2, U4, and U5 snRNPs that direct pre-mRNA splicing. Using human snRNP structures to guide mutagenesis in Saccharomyces cerevisiae, we gained new insights into structure–function relationships of the SmG, SmE, and SmF subunits. An alanine scan of 19 conserved amino acids of these three proteins, comprising the Sm RNA binding sites or inter-subunit interfaces, revealed that, with the exception of Arg74 in SmF, none are essential for yeast growth. Yet, for SmG, SmE, and SmF, as for many components of the yeast spliceosome, the effects of perturbing protein–RNA and protein–protein interactions are masked by built-in functional redundancies of the splicing machine. For example, tests for genetic interactions with non-Sm splicing factors showed that many benign mutations of SmG, SmE, and SmF (and of SmB and SmD3) were synthetically lethal with null alleles of U2 snRNP subunits Lea1 and Msl1. Tests of pairwise combinations of SmG, SmE, SmF, SmB, and SmD3 alleles highlighted the inherent redundancies within the Sm ring, whereby simultaneous mutations of the RNA binding sites of any two of the Sm subunits are lethal. Our results suggest that six intact RNA binding sites in the Sm ring suffice for function but five sites may not. PMID:27417296

SNP identification in FBXO32 gene and their associations with growth traits in cattle.

PubMed

Wang, Ailan; Zhang, Ya; Li, Mijie; Lan, Xianyong; Wang, Juqiang; Chen, Hong

2013-02-15

The F-box protein 32 (FBXO32), also known as Atrogin-1, is one of the four subunits of the ubiquitin protein ligase complex. FBXO32 has been previously shown to be involved in regulation of initiation and development of muscle mass. In the present study, we investigated the polymorphism of FBXO32 gene in 1313 cattle from seven bovine breeds using DNA sequencing, polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and PCR-based amplification-created restriction site (PCR-ACRS) methods. Four novel single nucleotide polymorphisms (SNPs) were identified within bovine FBXO32, and were deposited in the GenBank database. The association studies between these four SNPs and growth traits were performed in NanYang cattle. Notably, the SNPs ss411628932 and ss411628936 were shown to be significantly associated with body length of 24-month-old NanYang cattle. Based on the above four SNPs, 16 haplotypes were identified. The main haplotype was AATA, which occurred at a frequency of more than 40%. Additionally, phylogenetic analysis showed that geographical distance was essential to gene flow among seven cattle breeds. Indigenous bovine breeds displayed genetic difference in comparison to hybrid bovine breeds that have foreign origins. We herein describe for the first time a comprehensive study on the variability of bovine FBXO32 gene that is predictive of genetic potential for body length phenotype. Copyright © 2012 Elsevier B.V. All rights reserved.

Identification of relevant single-nucleotide polymorphisms in Pneumocystis jirovecii: relationship with clinical data.

PubMed

Esteves, F; Gaspar, J; Marques, T; Leite, R; Antunes, F; Mansinho, K; Matos, O

2010-07-01

Pneumocystis jirovecii is a poorly understood pathogen that causes opportunistic pneumonia (Pneumocystis pneumonia (PcP)) in patients with AIDS. The present study was aimed at correlating genetic differences in P. jirovecii isolates and clinical patient data. A description of genetic diversity in P. jirovecii isolates from human immunodeficiency virus-positive patients, based on the identification of multiple single-nucleotide polymorphisms (SNPs) at five distinct loci encoding mitochondrial large-subunit rRNA (mtLSU rRNA), cytochrome b (CYB), superoxide dismutase (SOD), dihydrofolate reductase (DHFR), and dihydropteroate synthase (DHPS), was achieved using PCR with DNA sequencing and restriction fragment length polymorphism analysis. The statistical analysis revealed several interesting correlations among the four most relevant SNPs (mt85, SOD110, SOD215, and DHFR312) and specific clinical parameters: mt85C was associated with undiagnosed or atypical PcP episodes and favourable follow-up; SOD215C was associated with favourable follow-up; and DHFR312T was associated with PcP cases presenting moderate to high parasite burdens. The genotypes mt85C/SOD215C and SOD110T/SOD215C were found to be associated with less virulent P. jirovecii infections, whereas the genotype SOD110T/SOD215T was found to be related to more virulent PcP episodes. The present work demonstrated that potential P. jirovecii haplotypes may be related to the clinical data and outcome of PcP.

Dissemination of the highly expressed Bx7 glutenin subunit (Glu-B1al allele) in wheat as revealed by novel PCR markers and RP-HPLC.

PubMed

Butow, B J; Gale, K R; Ikea, J; Juhász, A; Bedö, Z; Tamás, L; Gianibelli, M C

2004-11-01

Increased expression of the high molecular weight glutenin subunit (HMW-GS) Bx7 is associated with improved dough strength of wheat (Triticum aestivum L.) flour. Several cultivars and landraces of widely different genetic backgrounds from around the world have now been found to contain this so-called 'over-expressing' allelic form of the Bx7 subunit encoded by Glu-B1al. Using three methods of identification, SDS-PAGE, RP-HPLC and PCR marker analysis, as well as pedigree information, we have traced the distribution and source of this allele from a Uruguayan landrace, Americano 44D, in the mid-nineteenth century. Results are supported by knowledge of the movement of wheat lines with migrants. All cultivars possessing the Glu-B1al allele can be identified by the following attributes: (1) the elution of the By sub-unit peak before the Dx sub-unit peak by RP-HPLC, (2) high expression levels of Bx7 (>39% Mol% Bx), (3) a 43 bp insertion in the matrix-attachment region (MAR) upstream of the gene promoter relative to Bx7 and an 18 bp nucleotide duplication in the coding region of the gene. Evidence is presented indicating that these 18 and 43 bp sequence insertions are not causal for the high expression levels of Bx7 as they were also found to be present in a small number of hexaploid species, including Chinese Spring, and species expressing Glu-B1ak and Glu-B1a alleles. In addition, these sequence inserts were found in different isolates of the tetraploid wheat, T. turgidum, indicating that these insertion/deletion events occurred prior to hexaploidization.

Identification of potential platelet alloantigens in the Equidae family by comparison of gene sequences encoding major platelet membrane glycoproteins.

PubMed

Boudreaux, Mary K; Humphries, Drew M

2013-12-01

Platelet alloantigens in horses may play an important role in the development of neonatal alloimmune thrombocytopenia (NAIT). The objective of this study was to evaluate genes encoding major platelet glycoproteins within the Equidae family in an effort to identify potential alloantigens. DNA was isolated from blood samples obtained from Equidae family members, including a Holsteiner-Oldenburg cross, a Quarter horse, a donkey, and a Plains zebra (Equus burchelli). Gene sequences encoding equine platelet membrane glycoproteins IIb, IIIa (integrin subunits αIIb and β3), Ia (integrin subunit α2), and Ibα were determined using PCR. Gene sequences were compared to the equine genome available on GenBank. Polymorphisms that would be predicted to result in amino acid changes on platelet surfaces were documented and compared with known alloantigenic sites documented on human platelets. Amino acid differences were predicted based on nucleotide sequences for all 4 genes. Nine differences were documented for αIIb, 5 differences were documented for β3, 7 differences were documented for α2, and 16 differences were documented for Ibα outside the macroglycopeptide region. This study represents the first effort at identifying potential platelet alloantigens in members of the Equidae Family based on evaluation of gene sequences. The data obtained form the groundwork for identifying potential platelet alloantigens involved in transfusion reactions and neonatal alloimmune thrombocytopenia (NAIT). More work is required to determine whether the predicted amino acid differences documented in this study play a role in alloimmunity, and whether other polymorphisms not detected in this study are present that may result in alloimmunity. © 2013 American Society for Veterinary Clinical Pathology.

Methadone pharmacogenetics: CYP2B6 polymorphisms determine plasma concentrations, clearance and metabolism

PubMed Central

Kharasch, Evan D.; Regina, Karen J.; Blood, Jane; Friedel, Christina

2015-01-01

Background Interindividual variability in methadone disposition remains unexplained, and methadone accidental overdose in pain therapy is a significant public health problem. Cytochrome P4502B6 (CYP2B6) is the principle determinant of clinical methadone elimination. The CYP2B6 gene is highly polymorphic, with several variant alleles. CYP2B6.6, the protein encoded by the CYP2B6*6 polymorphism, deficiently catalyzes methadone metabolism in vitro. This investigation determined the influence of CYP2B6*6, and other allelic variants encountered, on methadone concentrations, clearance, and metabolism. Methods Healthy volunteers in genotype cohorts CYP2B6*1/*1 (n=21), CYP2B6*1/*6 (n=20), and CYP2B6*6/*6 (n=17), and also CYP2B6*1/*4 (n=1), CYP2B6*4/*6 (n=3), CYP2B6*5/*5 (n=2) subjects received single doses of intravenous and oral methadone. Plasma and urine methadone and metabolite concentrations were determined by tandem mass spectrometry. Results Average S-methadone apparent oral clearance was 35 and 45% lower in CYP2B6*1/*6 and CYP2B6*6/*6 genotypes, respectively, compared with CYP2B6*1/*1, and R-methadone apparent oral clearance was 25 and 30% lower. R- and S-methadone apparent oral clearance was 3- and 4-fold greater in CYP2B6*4 carriers. Intravenous and oral R- and S-methadone metabolism was significantly lower in CYP2B6*6 carriers compared with CYP2B6*1 homozygotes, and greater in CYP2B6*4 carriers. Methadone metabolism and clearance were lower in African-Americans due to the CYP2B6*6 genetic polymorphism. Conclusions CYP2B6 polymorphisms influence methadone plasma concentrations, due to altered methadone metabolism and thus clearance. Genetic influence is greater for oral than intravenous, and S- than R-methadone. CYP2B6 pharmacogenetics explains, in part, interindividual variability in methadone elimination. CYP2B6 genetic effects on methadone metabolism and clearance may identify subjects at risk for methadone toxicity and drug interactions. PMID:26389554

Differential Phosphorylation of Plant Translation Initiation Factors by Arabidopsis thaliana CK2 Holoenzymes*

PubMed Central

Dennis, Michael D.; Browning, Karen S.

2009-01-01

A previously described wheat germ protein kinase (Yan, T. F., and Tao, M. (1982) J. Biol. Chem. 257, 7037–7043) was identified unambiguously as CK2 using mass spectrometry. CK2 is a ubiquitous eukaryotic protein kinase that phosphorylates a wide range of substrates. In previous studies, this wheat germ kinase was shown to phosphorylate eIF2α, eIF3c, and three large subunit (60 S) ribosomal proteins (Browning, K. S., Yan, T. F., Lauer, S. J., Aquino, L. A., Tao, M., and Ravel, J. M. (1985) Plant Physiol. 77, 370–373). To further characterize the role of CK2 in the regulation of translation initiation, Arabidopsis thaliana catalytic (α1 and α2) and regulatory (β1, β2, β3, and β4) subunits of CK2 were cloned and expressed in Escherichia coli. Recombinant A. thaliana CK2β subunits spontaneously dimerize and assemble into holoenzymes in the presence of either CK2α1 or CK2α2 and exhibit autophosphorylation. The purified CK2 subunits were used to characterize the properties of the individual subunits and their ability to phosphorylate various plant protein substrates. CK2 was shown to phosphorylate eIF2α, eIF2β, eIF3c, eIF4B, eIF5, and histone deacetylase 2B but did not phosphorylate eIF1, eIF1A, eIF4A, eIF4E, eIF4G, eIFiso4E, or eIFiso4G. Differential phosphorylation was exhibited by CK2 in the presence of various regulatory β-subunits. Analysis of A. thaliana mutants either lacking or overexpressing CK2 subunits showed that the amount of eIF2β protein present in extracts was affected, which suggests that CK2 phosphorylation may play a role in eIF2β stability. These results provide evidence for a potential mechanism through which the expression and/or subcellular distribution of CK2 β-subunits could participate in the regulation of the initiation of translation and other physiological processes in plants. PMID:19509278

Prognostic role of the CDNK1B V109G polymorphism in multiple endocrine neoplasia type 1.

PubMed

Circelli, Luisa; Ramundo, Valeria; Marotta, Vincenzo; Sciammarella, Concetta; Marciello, Francesca; Del Prete, Michela; Sabatino, Lina; Pasquali, Daniela; Izzo, Francesco; Scala, Stefania; Colao, Annamaria; Faggiano, Antongiulio; Colantuoni, Vittorio

2015-07-01

CDKN1B encodes the cyclin-dependent kinase inhibitor p27/Kip1. CDKN1B mutations and polymorphisms are involved in tumorigenesis; specifically, the V109G single nucleotide polymorphism has been linked to different tumours with controversial results. Multiple endocrine neoplasia type 1 (MEN1) is a rare autosomal dominant syndrome, characterized by the development of different types of neuroendocrine tumours and increased incidence of other malignancies. A clear genotype-phenotype correlation in MEN1 has not been established yet. In this study, we assessed whether the CDKN1B V109G polymorphism was associated with the development of aggressive tumours in 55 consecutive patients affected by MEN1. The polymorphism was investigated by PCR amplification of germline DNA followed by direct sequencing. Baseline and follow-up data of tumour types and their severity were collected and associated with the genetic data. MEN1-related aggressive and other malignant tumours of any origin were detected in 16.1% of wild-type and 33.3% of polymorphism allele-bearing patients (P = NS). The time interval between birth and the first aggressive tumour was significantly shorter in patients with the CDKN1B V109G polymorphism (median 46 years) than in those without (median not reached; P = 0.03). Similarly, shorter was the time interval between MEN1 diagnosis and age of the first aggressive tumour (P = 0.02). Overall survival could not be estimated as 96% patients were still alive at the time of the study. In conclusion, CDKN1B V109G polymorphism seems to play a role in the development of aggressive tumours in MEN1. © 2015 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

Purification, crystallization and preliminary X-ray analysis of the regulatory subunit of aspartate kinase from Thermus thermophilus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yoshida, Ayako; Tomita, Takeo; Kuzuyama, Tomohisa

2007-02-01

To elucidate the mechanism of regulation of aspartate kinase, the regulatory subunit (the β subunit of T. thermophilus aspartate kinase) was crystallized in the presence of the inhibitor threonine. Aspartate kinase (AK) from Thermus thermophilus, which catalyzes the first step of threonine and methionine biosynthesis, is regulated via feedback inhibition by the end product threonine. To elucidate the mechanism of regulation of AK, the regulatory subunit (the β subunit of T. thermophilus AK) was crystallized in the presence of the inhibitor threonine. Diffraction data were collected to 2.15 Å at a synchrotron source. The crystal belongs to the cubic spacemore » group P4{sub 3}32 or P4{sub 1}32, with unit-cell parameters a = b = c = 141.8 Å.« less

In vivo reconstitution of a homodimeric cytochrome b559 like structure: The role of the N-terminus α-subunit from Synechocystis sp. PCC 6803.

PubMed

Luján, María A; Martínez, Jesús I; Alonso, Pablo J; Torrado, Alejandro; Roncel, Mercedes; Ortega, José M; Sancho, Javier; Picorel, Rafael

2015-11-01

The cytochrome b559 is a heme-bridged heterodimeric protein with two subunits, α and β. Both subunits from Synechocystis sp. PCC 6803 have previously been cloned and overexpressed in Escherichia coli and in vivo reconstitution experiments have been carried out. The formation of homodimers in the bacterial membrane with endogenous heme was only observed in the case of the β-subunit (β/β) but not with the full length α-subunit. In the present work, reconstitution of a homodimer (α/α) cytochrome b559 like structure was possible using a chimeric N-terminus α-subunit truncated before the amino acid isoleucine 17, eliminating completely a short amphipathic α-helix that lays on the surface of the membrane. Overexpression and in vivo reconstitution in the bacteria was clearly demonstrated by the brownish color of the culture pellet and the use of a commercial monoclonal antibody against the fusion protein carrier, the maltoside binding protein, and polyclonal antibodies against a synthetic peptide of the α-subunit from Thermosynechococcus elongatus. Moreover, a simple partial purification after membrane solubilization with Triton X-100 confirmed that the overexpressed protein complex corresponded with the maltoside binding protein-chimeric α-subunit cytochrome b559 like structure. The features of the new structure were determined by UV-Vis, electron paramagnetic resonance and redox potentiometric techniques. Ribbon representations of all possible structures are also shown to better understand the mechanism of the cytochrome b559 maturation in the bacterial cytoplasmic membrane. Copyright © 2015 Elsevier B.V. All rights reserved.

A functional thyrotropin- and growth hormone-secreting pituitary adenoma with a ultrastructurally monomorphic feature: a case study.

PubMed

Ozawa, Y; Kameya, T; Kasuga, A; Naritaka, H; Kanda, N; Maruyama, H; Saruta, T

1998-04-01

A 38-yr-old female with a TSH- and GH-secreting pituitary adenoma is described, who had both overt symptoms, hyperthyroidism and acromegaly. Her serum TSH was not suppressed despite high concentrations of free T3 and free T4, and her alpha-subunit/TSH molar ratio was high. Her serum GH was consistently high, and was not suppressed by an oral glucose tolerance test. Preoperative testing revealed that, although the TSH response was impaired, TSH, alpha-subunit and GH were increased by TRH injection, and that these hormones were reduced by bromocriptine or somatostatin analog. Although she did not have hyperprolactinemia, the in vitro culture and immunohistochemical studies revealed that the adenoma cells produced and released PRL, in addition to TSH, alpha-subunit and GH. Immunohistochemical studies showed the presence of GH in the cytoplasm of many adenoma cells. TSH beta-positive adenoma cells were less frequently seen than GH-positive adenoma cells. No cells showed the coexistence of GH and TSH beta, and a few cells were positive for PRL. By electron microscopy, the adenoma was found to be composed of a single cell type resembling thyrotrophs, and did not have any characteristics of somatotrophs. This case was considered to be of interest, because the adenoma was ultrastructurally monomorphous, but immunohistochemically polymorphous.

High-resolution melting analysis of the single nucleotide polymorphism hot-spot region in the rpoB gene as an indicator of reduced susceptibility to rifaximin in Clostridium difficile.

PubMed

Pecavar, Verena; Blaschitz, Marion; Hufnagl, Peter; Zeinzinger, Josef; Fiedler, Anita; Allerberger, Franz; Maass, Matthias; Indra, Alexander

2012-06-01

Clostridium difficile, a Gram-positive, spore-forming, anaerobic bacterium, is the main causative agent of hospital-acquired diarrhoea worldwide. In addition to metronidazole and vancomycin, rifaximin, a rifamycin derivative, is a promising antibiotic for the treatment of recurring C. difficile infections (CDI). However, exposure of C. difficile to this antibiotic has led to the development of rifaximin-resistance due to point mutations in the β-subunit of the RNA polymerase (rpoB) gene. In the present study, 348 C. difficile strains with known PCR-ribotypes were investigated for respective single nucleotide polymorphisms (SNPs) within the proposed rpoB hot-spot region by using high-resolution melting (HRM) analysis. This method allows the detection of SNPs by comparing the altered melting behaviour of dsDNA with that of wild-type DNA. Discrimination between wild-type and mutant strains was enhanced by creating heteroduplexes by mixing sample DNA with wild-type DNA, leading to characteristic melting curve shapes from samples containing SNPs in the respective rpoB section. In the present study, we were able to identify 16 different rpoB sequence-types (ST) by sequencing analysis of a 325 bp fragment. The 16 PCR STs displayed a total of 24 different SNPs. Fifteen of these 24 SNPs were located within the proposed 151 bp SNP hot-spot region, resulting in 11 different HRM curve profiles (CP). Eleven SNPs (seven of which were within the proposed hot-spot region) led to amino acid substitutions associated with reduced susceptibility to rifaximin and 13 SNPs (eight of which were within the hot-spot region) were synonymous. This investigation clearly demonstrates that HRM analysis of the proposed SNP hot-spot region in the rpoB gene of C. difficile is a fast and cost-effective method for the identification of C. difficile samples with reduced susceptibility to rifaximin and even allows simultaneous SNP subtyping of the respective C. difficile isolates.

Comparison of CYP2C9, CYP2C19, CYP2D6, ABCB1, and SLCO1B1 gene-polymorphism frequency in Russian and Nanai populations

PubMed Central

Sychev, Dmitrij Alekseevitch; Shuev, Grigorij Nikolaevich; Suleymanov, Salavat Shejhovich; Ryzhikova, Kristina Anatol’evna; Mirzaev, Karin Badavievich; Grishina, Elena Anatol’evna; Snalina, Natalia Evgenievna; Sozaeva, Zhannet Alimovna; Grabuzdov, Anton Mikhailovich; Matsneva, Irina Andreevna

2017-01-01

Background The efficiency and safety of drug therapy depends on the peculiarities of functioning of the P450 cytochrome group and transporting proteins. There are significant differences for single-nucleotide polymorphism (SNP) frequency. Materials and methods We studied the peculiarities of P450 cytochrome polymorphisms, SLCO1B1 transporting protein, and P-glycoprotein carriage in healthy volunteers in the Nanai ethnic group living in Russia, and compared them to the carriage of SNPs in the Russian population according to literature data. Results After performing the real-time polymerase chain reactions on the samples from 70 healthy volunteers from the Nanai group, for the CYP2C9*2C430T polymorphism we determined 70 CC-genotype carriers. As for the CYP2C9*3A1075C polymorphism, we found 62 AA-genotype carriers and eight AC-genotype carriers. For the CYP2C19*2G681A polymorphism, we determined 39 GG-genotype carriers and 28 GA-genotype carriers, for the CYP2C19*3G636A polymorphism 58 GG-genotype carriers and 12 GA-genotype carriers, and for the CYP2C19*17C806T polymorphism 67 CC-genotype carriers and three CT-genotype carriers. For the CYP2D6*4G1846A polymorphism, the GG genotype had 68 carriers, and the GA genotype two carriers. For the ABCB1*6C3435T polymorphism, there were 19 CC-genotype carriers and 39 CT-genotype carriers. For the SLCO1B1*5T521C polymorphism, the TT genotype had 41 carriers and the CT genotype 25 carriers. The distribution of genotypes fitted the Hardy–Weinberg equilibrium for all the polymorphisms, except those of CYP2C9*2. There were also significant differences in allele frequencies for some polymorphisms between the Nanais and the Russians. Conclusion In the Nanai population, there are polymorphisms connected with the decrease in safety and efficiency of drug therapy. Studying the ethnic differences might influence the determination of priority in the introduction of pharmacogenetic tests in clinical practice in different regions of Russia. PMID:28435307

Cloning and functional characterization of inward-rectifying potassium (Kir) channels from Malpighian tubules of the mosquito Aedes aegypti

PubMed Central

Piermarini, Peter M.; Rouhier, Matthew F.; Schepel, Matthew; Kosse, Christin; Beyenbach, Klaus W.

2013-01-01

Inward-rectifying K+ (Kir) channels play critical physiological roles in a variety of vertebrate cells/tissues, including the regulation of membrane potential in nerve and muscle, and the transepithelial transport of ions in osmoregulatory epithelia, such as kidneys and gills. It remains to be determined whether Kir channels play similar physiological roles in insects. In the present study, we sought to 1) clone the cDNAs of Kir channel subunits expressed in the renal (Malpighian) tubules of the mosquito Aedes aegypti, and 2) characterize the electrophysiological properties of the cloned Kir subunits when expressed heterologously in oocytes of Xenopus laevis. Here, we reveal that three Kir subunits are expressed abundantly in Aedes Malpighian tubules (AeKir1, AeKir2B, and AeKir3); each of their full-length cDNAs was cloned. Heterologous expression of the AeKir1 or the AeKir2B subunits in Xenopus oocytes elicits inward-rectifying K+ currents that are blocked by barium. Relative to the AeKir2B-expressing oocytes, the AeKir1-expressing oocytes 1) produce larger macroscopic currents, and 2) exhibit a modulation of their conductive properties by extracellular Na+. Attempts to functionally characterize the AeKir3 subunit in Xenopus oocytes were unsuccessful. Lastly, we show that in isolated Aedes Malpighian tubules, the cation permeability sequence of the basolateral membrane of principal cells (Tl+ > K+ > Rb+ > NH4+) is consistent with the presence of functional Kir channels. We conclude that in Aedes Malpighian tubules, Kir channels contribute to the majority of the barium-sensitive transepithelial transport of K+. PMID:23085358

Low-molecular-weight glutenin subunits from the 1U genome of Aegilops umbellulata confer superior dough rheological properties and improve breadmaking quality of bread wheat.

PubMed

Wang, Jian; Wang, Chang; Zhen, Shoumin; Li, Xiaohui; Yan, Yueming

2018-04-01

Wheat-related genomes may carry new glutenin genes with the potential for quality improvement of breadmaking. In this study, we estimated the gluten quality properties of the wheat line CNU609 derived from crossing between Chinese Spring (CS, Triticum aestivum L., 2n = 6x = 42, AABBDD) and the wheat Aegilops umbellulata (2n = 2x = 14, UU) 1U(1B) substitution line, and investigated the function of 1U-encoded low-molecular-weight glutenin subunits (LMW-GS). The main quality parameters of CNU609 were significantly improved due to introgression of the 1U genome, including dough development time, stability time, farinograph quality number, gluten index, loaf size and inner structure. Glutenin analysis showed that CNU609 and CS had the same high-molecular-weight glutenin subunit (HMW-GS) composition, but CNU609 carried eight specific 1U genome-encoded LMW-GS. The introgression of the 1U-encoded LMW-GS led to more and larger protein body formation in the CNU609 endosperm. Two new LMW-m type genes from the 1U genome, designated Glu-U3a and Glu-U3b, were cloned and characterized. Secondary structure prediction implied that both Glu-U3a and Glu-U3b encode subunits with high α-helix and β-strand content that could benefit the formation of superior gluten structure. Our results indicate that the 1U genome has superior LMW-GS that can be used as new gene resources for wheat gluten quality improvement. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Induction and expression of GluA1 (GluR-A)-independent LTP in the hippocampus

PubMed Central

Romberg, Carola; Raffel, Joel; Martin, Lucy; Sprengel, Rolf; Seeburg, Peter H; Rawlins, J Nicholas P; Bannerman, David M; Paulsen, Ole

2009-01-01

Long-term potentiation (LTP) at hippocampal CA3–CA1 synapses is thought to be mediated, at least in part, by an increase in the postsynaptic surface expression of α-amino-3-hydroxy-5-methyl-4-isoxazole proprionic acid (AMPA) receptors induced by N-methyl-d-aspartate (NMDA) receptor activation. While this process was originally attributed to the regulated synaptic insertion of GluA1 (GluR-A) subunit-containing AMPA receptors, recent evidence suggests that regulated synaptic trafficking of GluA2 subunits might also contribute to one or several phases of potentiation. However, it has so far been difficult to separate these two mechanisms experimentally. Here we used genetically modified mice lacking the GluA1 subunit (Gria1−/− mice) to investigate GluA1-independent mechanisms of LTP at CA3–CA1 synapses in transverse hippocampal slices. An extracellular, paired theta-burst stimulation paradigm induced a robust GluA1-independent form of LTP lacking the early, rapidly decaying component characteristic of LTP in wild-type mice. This GluA1-independent form of LTP was attenuated by inhibitors of neuronal nitric oxide synthase and protein kinase C (PKC), two enzymes known to regulate GluA2 surface expression. Furthermore, the induction of GluA1-independent potentiation required the activation of GluN2B (NR2B) subunit-containing NMDA receptors. Our findings support and extend the evidence that LTP at hippocampal CA3–CA1 synapses comprises a rapidly decaying, GluA1-dependent component and a more sustained, GluA1-independent component, induced and expressed via a separate mechanism involving GluN2B-containing NMDA receptors, neuronal nitric oxide synthase and PKC. PMID:19302150

Correlation between protein kinase catalytic subunit alpha-1 gene rs13361707 polymorphism and gastric cancer susceptibility in asian populations

PubMed Central

Ni, Jianfeng; Shen, Nan; Tang, Jilei; Ren, Kewei

2017-01-01

A single nucleotide polymorphism (SNP) of the protein kinase catalytic subunit alpha-1 gene (PRKAA1) that confers susceptibility to gastric cancer (GC) was identified by genome-wide association in several case-control studies. However, the results remained controversial and ambiguous. Therefore, we performed a larger meta-analysis to confirm this association. We searched the PubMed, Embase, WanFang, and CNKI databases, without any restriction on language, covering all papers published until Feb 22, 2017. Overall, 14 case-control studies with 14,485 cases and 14,792 controls were retrieved based on the search criteria. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to quantify the strength of the association. Publication bias was assessed by Egger’s and Begg’s tests. We found that the PRKAA1 rs13361707 C/T polymorphism had no association with GC risk in any of the pooled genetic models (for example, the T-allele vs. C-allele allelic contrast model yielded the following estimates: OR = 0.87, 95% CI = 0.73–1.05, Pheterogeneity = 0.000). Furthermore, in analyses stratified by either source of control or geographical origin of subjects, a statistically significant inverse relationship was detected between PRKAA1 rs13361707 C/T polymorphism and GC risk. No obvious evidence of publication bias was detected in the pooled meta-analysis. Furthermore, we observed that individuals carrying T-allele (TT or TC) genotypes had a lower expression of PRKAA1. Our present study indicated that PRKAA1 rs13361707 C/T was not significantly associated with GC risk, despite few positive results in the subgroups. PMID:28978122

Association of Mitochondrial DNA 10398 Polymorphism in Invasive Breast Cancer in Malay Population of Peninsular Malaysia

PubMed Central

Tengku Baharudin, Nadiah; Jaafar, Hasnan; Zainuddin, Zafarina

2012-01-01

Background: The mitochondrial DNA (mtDNA) 10398 polymorphism is hypothesised to alter a mitochondrial subunit of the electron transfer chain and is associated with several neurodegenerative disorders and cancers. Methods: In this study, an mtDNA polymorphism at nucleotide position 10398 was screened in 101 Malay female patients with invasive breast cancer and 90 age-matched healthy female controls using minisequencing analysis. Results: The Malay women with the 10398G variant showed a significantly increased risk of invasive breast cancer (OR = 2.29, 95% CI 1.25–4.20, P = 0.007). Immunohistochemistry analysis was conducted to investigate the effect of this polymorphism on the levels of apoptosis in breast cancer cells. The level of Bax (a pro-apoptotic protein) expression was significantly higher than that of Bcl-2 (an anti-apoptotic protein) in patients carrying the G allele (P = 0.016) but not in those carrying the A allele (P = 0.48). Conclusion: Based on these findings, we propose that the mtDNA 10398 polymorphism may be a potential risk marker for breast cancer susceptibility in the Malay population. PMID:22977373

Intragenomic polymorphisms among high-copy loci: a genus-wide study of nuclear ribosomal DNA in Asclepias (Apocynaceae).

PubMed

Weitemier, Kevin; Straub, Shannon C K; Fishbein, Mark; Liston, Aaron

2015-01-01

Despite knowledge that concerted evolution of high-copy loci is often imperfect, studies that investigate the extent of intragenomic polymorphisms and comparisons across a large number of species are rarely made. We present a bioinformatic pipeline for characterizing polymorphisms within an individual among copies of a high-copy locus. Results are presented for nuclear ribosomal DNA (nrDNA) across the milkweed genus, Asclepias. The 18S-26S portion of the nrDNA cistron of Asclepias syriaca served as a reference for assembly of the region from 124 samples representing 90 species of Asclepias. Reads were mapped back to each individual's consensus and at each position reads differing from the consensus were tallied using a custom perl script. Low frequency polymorphisms existed in all individuals (mean = 5.8%). Most nrDNA positions (91%) were polymorphic in at least one individual, with polymorphic sites being less frequent in subunit regions and loops. Highly polymorphic sites existed in each individual, with highest abundance in the "noncoding" ITS regions. Phylogenetic signal was present in the distribution of intragenomic polymorphisms across the genus. Intragenomic polymorphisms in nrDNA are common in Asclepias, being found at higher frequency than any other study to date. The high and variable frequency of polymorphisms across species highlights concerns that phylogenetic applications of nrDNA may be error-prone. The new analytical approach provided here is applicable to other taxa and other high-copy regions characterized by low coverage genome sequencing (genome skimming).

Distinguishing functional polymorphism from random variation in the sequences of >10,000 HLA-A, -B and -C alleles.

PubMed

Robinson, James; Guethlein, Lisbeth A; Cereb, Nezih; Yang, Soo Young; Norman, Paul J; Marsh, Steven G E; Parham, Peter

2017-06-01

HLA class I glycoproteins contain the functional sites that bind peptide antigens and engage lymphocyte receptors. Recently, clinical application of sequence-based HLA typing has uncovered an unprecedented number of novel HLA class I alleles. Here we define the nature and extent of the variation in 3,489 HLA-A, 4,356 HLA-B and 3,111 HLA-C alleles. This analysis required development of suites of methods, having general applicability, for comparing and analyzing large numbers of homologous sequences. At least three amino-acid substitutions are present at every position in the polymorphic α1 and α2 domains of HLA-A, -B and -C. A minority of positions have an incidence >1% for the 'second' most frequent nucleotide, comprising 70 positions in HLA-A, 85 in HLA-B and 54 in HLA-C. The majority of these positions have three or four alternative nucleotides. These positions were subject to positive selection and correspond to binding sites for peptides and receptors. Most alleles of HLA class I (>80%) are very rare, often identified in one person or family, and they differ by point mutation from older, more common alleles. These alleles with single nucleotide polymorphisms reflect the germ-line mutation rate. Their frequency predicts the human population harbors 8-9 million HLA class I variants. The common alleles of human populations comprise 42 core alleles, which represent all selected polymorphism, and recombinants that have assorted this polymorphism.

Distinguishing functional polymorphism from random variation in the sequences of >10,000 HLA-A, -B and -C alleles

PubMed Central

Cereb, Nezih; Yang, Soo Young; Marsh, Steven G. E.; Parham, Peter

2017-01-01

HLA class I glycoproteins contain the functional sites that bind peptide antigens and engage lymphocyte receptors. Recently, clinical application of sequence-based HLA typing has uncovered an unprecedented number of novel HLA class I alleles. Here we define the nature and extent of the variation in 3,489 HLA-A, 4,356 HLA-B and 3,111 HLA-C alleles. This analysis required development of suites of methods, having general applicability, for comparing and analyzing large numbers of homologous sequences. At least three amino-acid substitutions are present at every position in the polymorphic α1 and α2 domains of HLA-A, -B and -C. A minority of positions have an incidence >1% for the ‘second’ most frequent nucleotide, comprising 70 positions in HLA-A, 85 in HLA-B and 54 in HLA-C. The majority of these positions have three or four alternative nucleotides. These positions were subject to positive selection and correspond to binding sites for peptides and receptors. Most alleles of HLA class I (>80%) are very rare, often identified in one person or family, and they differ by point mutation from older, more common alleles. These alleles with single nucleotide polymorphisms reflect the germ-line mutation rate. Their frequency predicts the human population harbors 8–9 million HLA class I variants. The common alleles of human populations comprise 42 core alleles, which represent all selected polymorphism, and recombinants that have assorted this polymorphism. PMID:28650991

Crystal structures of RIalpha subunit of cyclic adenosine 5'-monophosphate (cAMP)-dependent protein kinase complexed with (Rp)-adenosine 3',5'-cyclic monophosphothioate and (Sp)-adenosine 3',5'-cyclic monophosphothioate, the phosphothioate analogues of cAMP.

PubMed

Wu, Jian; Jones, John M; Nguyen-Huu, Xuong; Ten Eyck, Lynn F; Taylor, Susan S

2004-06-01

Cyclic adenosine 5'-monophosphate (cAMP) is an ancient signaling molecule, and in vertebrates, a primary target for cAMP is cAMP-dependent protein kinase (PKA). (R(p))-adenosine 3',5'-cyclic monophosphothioate ((R(p))-cAMPS) and its analogues are the only known competitive inhibitors and antagonists for cAMP activation of PKA, while (S(p))-adenosine 3',5'-cyclic monophosphothioate ((S(p))-cAMPS) functions as an agonist. The crystal structures of a Delta(1-91) deletion mutant of the RIalpha regulatory subunit of PKA bound to (R(p))-cAMPS and (S(p))-cAMPS were determined at 2.4 and 2.3 A resolution, respectively. While the structures are similar to each other and to the crystal structure of RIalpha bound to cAMP, differences in the dynamical properties of the protein when (R(p))-cAMPS is bound are apparent. The structures highlight the critical importance of the exocyclic oxygen's interaction with the invariant arginine in the phosphate binding cassette (PBC) and the importance of this interaction for the dynamical properties of the interactions that radiate out from the PBC. The conformations of the phosphate binding cassettes containing two invariant arginine residues (Arg209 on domain A, and Arg333 on domain B) are somewhat different due to the sulfur interacting with this arginine. Furthermore, the B-site ligand together with the entire domain B show significant differences in their overall dynamic properties in the crystal structure of Delta(1-91) RIalpha complexed with (R(p))-cAMPS phosphothioate analogue ((R(p))-RIalpha) compared to the cAMP- and (S(p))-cAMPS-bound type I and II regulatory subunits, based on the temperature factors. In all structures, two structural solvent molecules exist within the A-site ligand binding pocket; both mediate water-bridged interactions between the ligand and the protein. No structured waters are in the B-site pocket. Owing to the higher resolution data, the N-terminal segment (109-117) of the RIalpha subunit can also be traced. This strand forms an intermolecular antiparallel beta-sheet with the same strand in an adjacent molecule and implies that the RIalpha subunit can form a weak homodimer even in the absence of its dimerization domain.

[Correlation analysis between single nucleotide polymorphism of FGF5 gene and wool yield in rabbits].

PubMed

Li, Chun-Xiao; Jiang, Mei-Shan; Chen, Shi-Yi; Lai, Song-Jia

2008-07-01

Single nucleotide polymorphism (SNP) in exon 1 and 3 of fibroblast growth factor (FGF5) gene was studied by DNA sequencing in Yingjing angora rabbit, Tianfu black rabbit and California rabbit. A frameshift mutation (TCT insert) at base position 217 (site A) of exon 1 and a T/C missense mutation at base position 59 (site B) of exon 3 were found in Yingjing angora rabbit with a high frequency; a T/C same-sense mutation at base position 3 (site C) of exon 3 was found with similar frequency in three rabbit breeds. Least square analysis showed that different genotypes had no significant association with wool yield in site A, and had high significant association with wool yield in site B (P<0.01) and significant association with wool yield in site C (P<0.05). It was concluded from the results that FGF5 gene could be the potential major gene affecting wool yield or link with the major gene, and polymorphic loci B and C may be used as molecular markers for im-proving wool yield in angora rabbits.

Association Studies of Fcγ Receptor Polymorphisms with Outcome in HER2+ Breast Cancer Patients Treated with Trastuzumab in NCCTG (Alliance) Trial N9831

PubMed Central

Norton, Nadine; Olson, Rebecca M.; Pegram, Mark; Tenner, Kathleen; Ballman, Karla V.; Clynes, Raphael; Knutson, Keith L.; Perez, Edith A.

2014-01-01

Patients with HER2+ breast cancer treated with trastuzumab and chemotherapy have superior survival compared to patients treated with chemotherapy alone. Polymorphisms within FCGR2A and FCGR3A are associated with binding affinity of natural killer cells to the IgG1 portion of trastuzumab and a polymorphism in FCGR2B (I232T) is associated with impaired regulatory activity. The association of these polymorphisms with clinical response among trastuzumab-treated patients is equivocal with both positive and negative associations. We performed genotyping analysis on the FCGR3A V158F, FCGR2A R131H, and FCGR2B I232T genes in 1,325 patients from the N9831 clinical trial. Patients in Arm A (N=419) received chemotherapy only. Patients in Arms B (N=469) and C (N=437) were treated with chemotherapy and trastuzumab, (sequentially in Arm B and concurrently in Arm C). Using log-rank test and Cox proportional hazard models, we compared disease-free survival (DFS) among genotypic groups within pooled Arms B/C. We found no differences in DFS between trastuzumab-treated patients who had the FCGR3A 158 V/V and/or FCGR2A 131 H/H high affinity genotypes and patients without those genotypes. Furthermore, there was no significant interaction between FCGR3A and FCGR2A and treatment. However, there was a difference in DFS for FCGR2B I232T with I/I patients deriving benefit from trastuzumab (p<0.001) compared to the T carriers who did not (p=0.81). The interaction between FCGR2B genotype and treatment was statistically significant (p=0.03). Our analysis did not reveal an association between FcγR high affinity genotypes and outcomes. However, it appears that the FCGR2B inhibitory gene may be predictive of adjuvant trastuzumab benefit. PMID:24989892

The association of polymorphisms in the type 1 and 2 deiodinase genes with circulating thyroid hormone parameters and atrophy of the medial temporal lobe.

PubMed

de Jong, Frank Jan; Peeters, Robin P; den Heijer, Tom; van der Deure, Wendy M; Hofman, Albert; Uitterlinden, André G; Visser, Theo J; Breteler, Monique M B

2007-02-01

Thyroid function has been related to Alzheimer disease (AD) and neuroimaging markers thereof. Whether thyroid dysfunction contributes to or results from developing AD remains unclear. Variations in the deiodinase type 1 (DIO1) and type 2 (DIO2) genes that potentially alter thyroid hormone bioactivity may help in elucidating the role of thyroid function in AD. We investigated the association of recently identified polymorphisms in the DIO1 (D1a-C/T, D1b-A/G) and DIO2 (D2-ORFa-Gly3Asp, D2-Thr92Ala) genes with circulating thyroid parameters and early neuroimaging markers of AD. The Rotterdam Scan Study is a population-based cohort study among 1,077 elderly individuals aged 60-90 yr. DIO1 and DIO2 polymorphisms and serum TSH, free T4, T3, and reverse T3 (rT3) levels were determined in 995 nondemented elderly, including 473 persons with assessments of hippocampal and amygdalar volume on brain magnetic resonance imaging. Carriers of the D1a-T allele had higher serum free T4 and rT3, lower T3, and lower T3/rT3. The D1b-G allele was associated with higher serum T3 and T3/rT3. The DIO2 variants were not associated with serum thyroid parameters. No associations were found with hippocampal or amygdalar volume. This is the first study to report an association of D1a-C/T and D1b-A/G polymorphisms with iodothyronine levels in the elderly. Polymorphisms in the DIO1 and DIO2 genes are not associated with early magnetic resonance imaging markers of AD. This suggests that the previously reported association between iodothyronine levels and brain atrophy reflects comorbidity or nonthyroidal illness rather than thyroid hormones being involved in developing AD.

Replication Study of Polymorphisms Associated With Brain Arteriovenous Malformation in a Population From South of Brazil

PubMed Central

Ludwig, Fernanda S; Matte, Ursula S; Mota, Simone; Stefani, Marco A

2016-01-01

Introduction The aim of this study was to reproducibly determine if any of the polymorphisms were associated with the susceptibility to brain arteriovenous malformations (BAVM) or the risk of intracranial hemorrhage (ICH) presentation. Methods We recruited 63 BAVM patients and 96 controls. The polymorphisms selected for evaluation were apolipoprotein E (APOE), tumor necrosis factor alpha (TNF 238G>A - rs361525), interleukin 1 beta (IL1B 511C>T - rs16944 and IL1B -31T>C - rs1143627), activin-like kinase 1 (ACVRL1 IVS3-35A>G - rs2071219), endoglin (ENG 207G>A - rs11545664), and interleukin 6 (IL6 174G>C - rs1800795). Results In the single analysis, we observed statistically significant differences in the allele distributions for IL1B -31T>C (rs1143627) between the BAVM patients and control subjects (P = 0.02). There was a trend toward significance for the association between the IL1B 511C>T (rs16944) allele and BAVM risk (P = 0.07). In further logistic regression analysis, no polymorphism was significantly associated with the risk of BAVM. No polymorphisms were associated with hemorrhage presentation according to both single and multivariable analyses. Conclusions In our sample from a south Brazil population, we found no association between the risks of BAVM and ICH presentation with any of the selected polymorphisms. PMID:27026833

Replication Study of Polymorphisms Associated With Brain Arteriovenous Malformation in a Population From South of Brazil.

PubMed

Franciscatto, André Cerutti; Ludwig, Fernanda S; Matte, Ursula S; Mota, Simone; Stefani, Marco A

2016-02-24

The aim of this study was to reproducibly determine if any of the polymorphisms were associated with the susceptibility to brain arteriovenous malformations (BAVM) or the risk of intracranial hemorrhage (ICH) presentation. We recruited 63 BAVM patients and 96 controls. The polymorphisms selected for evaluation were apolipoprotein E (APOE), tumor necrosis factor alpha (TNF 238G>A - rs361525), interleukin 1 beta (IL1B 511C>T - rs16944 and IL1B -31T>C - rs1143627), activin-like kinase 1 (ACVRL1 IVS3-35A>G - rs2071219), endoglin (ENG 207G>A - rs11545664), and interleukin 6 (IL6 174G>C - rs1800795). In the single analysis, we observed statistically significant differences in the allele distributions for IL1B -31T>C (rs1143627) between the BAVM patients and control subjects (P = 0.02). There was a trend toward significance for the association between the IL1B 511C>T (rs16944) allele and BAVM risk (P = 0.07). In further logistic regression analysis, no polymorphism was significantly associated with the risk of BAVM. No polymorphisms were associated with hemorrhage presentation according to both single and multivariable analyses. In our sample from a south Brazil population, we found no association between the risks of BAVM and ICH presentation with any of the selected polymorphisms.

Rat gastric mucins recognized by monoclonal antibodies RGM21 and HIK1083: isolation of mucin species characteristic of the surface and glandular mucosa.

PubMed

Goso, Y; Ishihara, K; Kurihara, M; Sugaya, T; Hotta, K

1999-08-01

Whole mucins and reduced subunits were extracted from the corpus of the rat stomach. After purification by Sepharose CL-4B chromatography followed by cesium trifluoroacetate equilibrium centrifugation, they were analyzed by Sepharose CL-2B chromatography, rate-zonal sedimentation centrifugation, and Q-Sepharose chromatography. Monoclonal antibodies RGM21 and HIK1083, which histochemically stained mucins in the surface and glandular mucosa of the rat stomach, respectively, were used to detect the site-specific mucins. Although RGM21- and HIK1083-reactive mucins both had a multimerized structure, the density and size of both the whole mucins and reduced subunits differed, thus indicating the presence of distinct mucin species in the surface and glandular mucosa. The mucin subunits were separated into four fractions, UB, B1, B2a, and B2b, by Q-Sepharose chromatography. HIK1083 reacted mainly with UB, while RGM21 reacted with B1, B2a, and B2b. These results, combined with dot-blot, amino acid, and carbohydrate composition analyses, showed that the surface mucins may consist of three kinds of subunits. In contrast, the glandular mucins may consist of one kind of subunit which differs from that of surface mucins.

[NMDA-GluR Subunit Antibody-Positive Encephalitis: A Clinical Analysis of Five Cases].

PubMed

Kaneko, Chikako; Shakespear, Norshalena; Tuchiya, Mario; Kubo, Jin; Yamamoto, Teiji; Katayama, Soichi; Takahashi, Yukitoshi

2016-09-01

Five consecutive cases of anti-NMDA-receptor encephalitis that we encountered were marked by a rapidly fluctuating level of consciousness associated with psychotic and delirious mental states. Opisthotonus, catatonia, and rhythmic and non-rhythmic involuntary movements of the mouth and jaw were also characteristic features of these particular cases. Serious and potentially fatal problems included epilepsia partialis continua, partial and generalized seizures, and respiratory depression, resembling the symptoms of encephalitis lethargica. An epidemic of encephalitis lethargica, also known of Economo encephalitis, occurred around 1917. Magnetic resonance imaging revealed edema of the neocortex in two cases and electroencephalography showed polymorphic and monomorphic delta slowing in the acute stage, although electroencephalographic seizure activity were not apparent. Routine cerebrospinal fluid analyses revealed lymphocyte-dominant pleocytosis in three cases, but antibodies against the NMDA-GluR subunit, GluN2B N-terminal, were at a high level in the fluid. All patients recovered without apparent sequelae. Two patients found to have ovarian teratoma underwent surgery for tumor removal. Treatments included pulse intravenous methylprednisolone, high-dose immunoglobulin, and plasma exchange together with seizure control and respiratory support. However, rituximab and or cyclophosphamide pulse therapy should also be considered for intractable cases, as indicated by recent reports. (Received February 16, 2016; Accepted May 2, 2016; Published September 1, 2016).

Development and use of domain-specific antibodies in a characterization of the large subunits of soybean photosystem 1

NASA Technical Reports Server (NTRS)

Henry, R. L.; Takemoto, L. J.; Murphy, J.; Gallegos, G. L.; Guikema, J. A.; Spooner, B. S. (Principal Investigator)

1992-01-01

The molecular architecture of the soybean photosystem 1 reaction center complex was examined using a combination of surface labeling and immunological methodology on isolated thylakoid membranes. Synthetic peptides (12 to 14 amino acids in length) were prepared which correspond to the N-terminal regions of the 83 and 82.4 kDa subunits of photosystem 1 (the PsaA and PsaB proteins, respectively). Similarly, a synthetic peptide was prepared corresponding to the C-terminal region of the PsaB subunit. These peptides were conjugated to a carrier protein, and were used for the production of polyclonal antibodies in rabbits. The resulting sera could distinguish between the PsaA and PsaB photosystem 1 subunits by Western blot analysis, and could identify appropriate size classes of cyanogen bromide cleavage fragments as predicted from the primary sequences of these two subunits. When soybean thylakoid membranes were surface-labeled with N-hydroxysuccinimidobiotin, several subunits of the complete photosystem 1 lipid/protein complex incorporated label. These included the light harvesting chlorophyll proteins of photosystem 1, and peptides thought to aid in the docking of ferredoxin to the complex during photosynthetic electron transport. However, the PsaA and PsaB subunits showed very little biotinylation. When these subunits were examined for the domains to which biotin did attach, most of the observed label was associated with the N-terminal domain of the PsaA subunit, as identified using a domain-specific polyclonal antisera.

Role of the VDR Bsm I and Apa I polymorphisms in the risk of colorectal cancer in Kashmir.

PubMed

Rasool, Sabha; Kadla, Showkat A; Rasool, Vamiq; Qazi, Falak; Khan, Tanzeela; Shah, Nisar A; Ganai, Bashir A

2014-01-01

A case-control study aiming to evaluate the relationship between Bsm I and Apa I restriction fragment gene polymorphisms and colorectal cancer (CRC) was carried out in Kashmir, including a total of 368 subjects (180 cases and 188 controls). DNA samples extracted from the blood of the subjects were analyzed for 3' untranslated region (3' UTR) Apa I and Bsm I polymorphisms using restriction fragment length polymorphism-polymerase chain reaction (RFLP-PCR). A statistically significant 2.7-fold increased risk was observed in individuals found homozygous for the presence of the 'b' allele, in comparison to subjects homozygous for the 'B' allele (odds ratio (OR) 2.7, 95% confidence interval (CI) 1.49-4.86 (Bsm I)), and a statistically insignificant 2-fold increased risk was found among individuals with the 'aa' genotype, as compared to subjects with the 'AA' genotype (OR 2.017, 95% CI 0.86-4.7). Our study also yielded statistically significant results when the Apa I polymorphism was stratified by age (≤ 50 years) and dwelling area (rural area), and the Bsm I polymorphism by gender (male gender), suggesting a possible role of Apa I and Bsm I polymorphisms in the etiology of CRC in Kashmir. We conclude that Apa I and Bsm I single-nucleotide polymorphisms (SNPs) in the vitamin D receptor gene (VDR) might be associated with susceptibility to CRC among Kashmiris. © 2014 S. Karger GmbH, Freiburg.

The Large Subunit rDNA Sequence of Plasmodiophora brassicae Does not Contain Intra-species Polymorphism.

PubMed

Schwelm, Arne; Berney, Cédric; Dixelius, Christina; Bass, David; Neuhauser, Sigrid

2016-12-01

Clubroot disease caused by Plasmodiophora brassicae is one of the most important diseases of cultivated brassicas. P. brassicae occurs in pathotypes which differ in the aggressiveness towards their Brassica host plants. To date no DNA based method to distinguish these pathotypes has been described. In 2011 polymorphism within the 28S rDNA of P. brassicae was reported which potentially could allow to distinguish pathotypes without the need of time-consuming bioassays. However, isolates of P. brassicae from around the world analysed in this study do not show polymorphism in their LSU rDNA sequences. The previously described polymorphism most likely derived from soil inhabiting Cercozoa more specifically Neoheteromita-like glissomonads. Here we correct the LSU rDNA sequence of P. brassicae. By using FISH we demonstrate that our newly generated sequence belongs to the causal agent of clubroot disease. Copyright © 2016 The Authors. Published by Elsevier GmbH.. All rights reserved.

A Common Polymorphism in SCN2A Predicts General Cognitive Ability Through Effects on Prefrontal Cortex Physiology

PubMed Central

Scult, Matthew A.; Trampush, Joey W.; Zheng, Fengyu; Conley, Emily Drabant; Lencz, Todd; Malhotra, Anil K.; Dickinson, Dwight; Weinberger, Daniel R.; Hariri, Ahmad R.

2015-01-01

Here we provide novel convergent evidence across three independent cohorts of healthy adults (n=531) demonstrating that a common polymorphism in the gene encoding the α2 subunit of neuronal voltage-gated type II sodium channels (SCN2A) predicts human general cognitive ability or “g.” Using meta-analysis, we demonstrate that the minor T allele of a common polymorphism (rs10174400) in SCN2A is associated with significantly higher “g” independent of gender and age. We further demonstrate using resting-state fMRI data from our discovery cohort (n=236) that this genetic advantage may be mediated by increased capacity for information processing between the dorsolateral prefrontal cortex and dorsal anterior cingulate cortex, which support higher cognitive functions. Collectively, these findings fill a gap in our understanding of the genetics of general cognitive ability and highlight a specific neural mechanism through which a common polymorphism shapes inter-individual variation in “g.” PMID:25961639

Probing the Non-Canonical Interface for Agonist Interaction with an α5 Containing Nicotinic Acetylcholine Receptor*

PubMed Central

Marotta, Christopher B.; Dilworth, Crystal N.; Lester, Henry A.; Dougherty, Dennis A.

2014-01-01

Nicotinic acetylcholine receptors (nAChRs) containing the α5 subunit are of interest because genome-wide association studies and candidate gene studies have identified polymorphisms in the α5 gene that are linked to an increased risk for nicotine dependence, lung cancer, and/or alcohol addiction. To probe the functional impact of an α5 subunit on nAChRs, a method to prepare a homogeneous population of α5-containing receptors must be developed. Here we use a gain of function (9') mutation to isolate populations of α5-containing nAChRs for characterization by electrophysiology. We find that the α5 subunit modulates nAChR rectification when co-assembled with α4 and β2 subunits. We also probe the α5–α4 interface for possible ligand binding interactions. We find that mutations expected to ablate an agonist binding site involving the α5 subunit have no impact on receptor function. The most straightforward interpretation of this observation is that agonists do not bind at the α5–α4 interface, in contrast to what has recently been demonstrated for the α4–α4 interface in related receptors. In addition, our mutational results suggest that the α5 subunit does not replace the α4 or β2 subunits and is relegated to occupying only the auxiliary position of the pentameric receptor. PMID:24144909

Meta-analysis of genome-wide association studies identifies common susceptibility polymorphisms for colorectal and endometrial cancer near SH2B3 and TSHZ1.

PubMed

Cheng, Timothy H T; Thompson, Deborah; Painter, Jodie; O'Mara, Tracy; Gorman, Maggie; Martin, Lynn; Palles, Claire; Jones, Angela; Buchanan, Daniel D; Win, Aung Ko; Hopper, John; Jenkins, Mark; Lindor, Noralane M; Newcomb, Polly A; Gallinger, Steve; Conti, David; Schumacher, Fred; Casey, Graham; Giles, Graham G; Pharoah, Paul; Peto, Julian; Cox, Angela; Swerdlow, Anthony; Couch, Fergus; Cunningham, Julie M; Goode, Ellen L; Winham, Stacey J; Lambrechts, Diether; Fasching, Peter; Burwinkel, Barbara; Brenner, Hermann; Brauch, Hiltrud; Chang-Claude, Jenny; Salvesen, Helga B; Kristensen, Vessela; Darabi, Hatef; Li, Jingmei; Liu, Tao; Lindblom, Annika; Hall, Per; de Polanco, Magdalena Echeverry; Sans, Monica; Carracedo, Angel; Castellvi-Bel, Sergi; Rojas-Martinez, Augusto; Aguiar Jnr, Samuel; Teixeira, Manuel R; Dunning, Alison M; Dennis, Joe; Otton, Geoffrey; Proietto, Tony; Holliday, Elizabeth; Attia, John; Ashton, Katie; Scott, Rodney J; McEvoy, Mark; Dowdy, Sean C; Fridley, Brooke L; Werner, Henrica M J; Trovik, Jone; Njolstad, Tormund S; Tham, Emma; Mints, Miriam; Runnebaum, Ingo; Hillemanns, Peter; Dörk, Thilo; Amant, Frederic; Schrauwen, Stefanie; Hein, Alexander; Beckmann, Matthias W; Ekici, Arif; Czene, Kamila; Meindl, Alfons; Bolla, Manjeet K; Michailidou, Kyriaki; Tyrer, Jonathan P; Wang, Qin; Ahmed, Shahana; Healey, Catherine S; Shah, Mitul; Annibali, Daniela; Depreeuw, Jeroen; Al-Tassan, Nada A; Harris, Rebecca; Meyer, Brian F; Whiffin, Nicola; Hosking, Fay J; Kinnersley, Ben; Farrington, Susan M; Timofeeva, Maria; Tenesa, Albert; Campbell, Harry; Haile, Robert W; Hodgson, Shirley; Carvajal-Carmona, Luis; Cheadle, Jeremy P; Easton, Douglas; Dunlop, Malcolm; Houlston, Richard; Spurdle, Amanda; Tomlinson, Ian

2015-12-01

High-risk mutations in several genes predispose to both colorectal cancer (CRC) and endometrial cancer (EC). We therefore hypothesised that some lower-risk genetic variants might also predispose to both CRC and EC. Using CRC and EC genome-wide association series, totalling 13,265 cancer cases and 40,245 controls, we found that the protective allele [G] at one previously-identified CRC polymorphism, rs2736100 near TERT, was associated with EC risk (odds ratio (OR) = 1.08, P = 0.000167); this polymorphism influences the risk of several other cancers. A further CRC polymorphism near TERC also showed evidence of association with EC (OR = 0.92; P = 0.03). Overall, however, there was no good evidence that the set of CRC polymorphisms was associated with EC risk, and neither of two previously-reported EC polymorphisms was associated with CRC risk. A combined analysis revealed one genome-wide significant polymorphism, rs3184504, on chromosome 12q24 (OR = 1.10, P = 7.23 × 10(-9)) with shared effects on CRC and EC risk. This polymorphism, a missense variant in the gene SH2B3, is also associated with haematological and autoimmune disorders, suggesting that it influences cancer risk through the immune response. Another polymorphism, rs12970291 near gene TSHZ1, was associated with both CRC and EC (OR = 1.26, P = 4.82 × 10(-8)), with the alleles showing opposite effects on the risks of the two cancers.

Src-family-tyrosine kinase Lyn is critical for TLR2-mediated NF-κB activation through the PI 3-kinase signaling pathway.

PubMed

Toubiana, Julie; Rossi, Anne-Lise; Belaidouni, Nadia; Grimaldi, David; Pene, Frederic; Chafey, Philippe; Comba, Béatrice; Camoin, Luc; Bismuth, Georges; Claessens, Yann-Erick; Mira, Jean-Paul; Chiche, Jean-Daniel

2015-10-01

TLR2 has a prominent role in host defense against a wide variety of pathogens. Stimulation of TLR2 triggers MyD88-dependent signaling to induce NF-κB translocation, and activates a Rac1-PI 3-kinase dependent pathway that leads to transactivation of NF-κB through phosphorylation of the P65 NF-κB subunit. This transactivation pathway involves tyrosine phosphorylations. The role of the tyrosine kinases in TLR signaling is controversial, with discrepancies between studies using only chemical inhibitors and knockout mice. Here, we show the involvement of the tyrosine-kinase Lyn in TLR2-dependent activation of NF-κB in human cellular models, by using complementary inhibition strategies. Stimulation of TLR2 induces the formation of an activation cluster involving TLR2, CD14, PI 3-kinase and Lyn, and leads to the activation of AKT. Lyn-dependent phosphorylation of the p110 catalytic subunit of PI 3-kinase is essential to the control of PI 3-kinase biological activity upstream of AKT and thereby to the transactivation of NF-κB. Thus, Lyn kinase activity is crucial in TLR2-mediated activation of the innate immune response in human mononuclear cells. © The Author(s) 2015.

CFH Y402H polymorphism and the complement activation product C5a: effects on NF-κB activation and inflammasome gene regulation.

PubMed

Cao, Sijia; Wang, Jay Ching Chieh; Gao, Jiangyuan; Wong, Matthew; To, Elliott; White, Valerie A; Cui, Jing Z; Matsubara, Joanne A

2016-05-01

The Y402H polymorphism in the complement factor H (CFH) gene is an important risk factor for age-related macular degeneration (AMD). Complement activation products and proinflammatory cytokines are associated with this polymorphism at the systemic level, but less is known of the associations in the outer retina of the genotyped eye. Here we investigate complement activation products and their role in nuclear factor (NF)-κB activation and gene expression of the NLRP3 inflammasome pathway. Postmortem donor eyes were genotyped for the CFH Y402H polymorphism and assessed for complement C3a, C5a, interleukin (IL)-18 and tumour necrosis factor (TNF)-α. ARPE19 cells were stimulated basolaterally with C5a or TNF-α in polarised cultures. NF-κB activation was assessed with a reporter cell line. Gene expression of inflammasome-related (NLRP3, caspase-1, IL-1β and IL-18) and classic inflammatory (IL-6 and IL-8) genes was studied. The distribution of inflammasome products, IL-1β and IL-18, was studied in postmortem donor eyes with AMD pathologies. Eyes with the homozygous at-risk variant demonstrated higher levels of C5a, IL-18 and TNF-α in Bruch's membrane and choroid. C5a promoted NF-κB activation and upregulation of IL-18 in polarised ARPE19. TNF-α promoted NF-κB activation and gene expression of caspase-1, IL-1β, IL-18, IL-6 and IL-8, but downregulated NLRP3. In eyes with geographic atrophy, strong immunoreactivity was observed for inflammasome products IL-1β and IL-18 compared with age-matched controls. The at-risk polymorphism of the CFH Y402H may contribute to AMD disease process through increased complement and NF-κB activation, and the upregulation of IL-18, a product of inflammasome activation. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Epstein-Barr virus latent gene sequences as geographical markers of viral origin: unique EBNA3 gene signatures identify Japanese viruses as distinct members of the Asian virus family.

PubMed

Sawada, Akihisa; Croom-Carter, Deborah; Kondo, Osamu; Yasui, Masahiro; Koyama-Sato, Maho; Inoue, Masami; Kawa, Keisei; Rickinson, Alan B; Tierney, Rosemary J

2011-05-01

Polymorphisms in Epstein-Barr virus (EBV) latent genes can identify virus strains from different human populations and individual strains within a population. An Asian EBV signature has been defined almost exclusively from Chinese viruses, with little information from other Asian countries. Here we sequenced polymorphic regions of the EBNA1, 2, 3A, 3B, 3C and LMP1 genes of 31 Japanese strains from control donors and EBV-associated T/NK-cell lymphoproliferative disease (T/NK-LPD) patients. Though identical to Chinese strains in their dominant EBNA1 and LMP1 alleles, Japanese viruses were subtly different at other loci. Thus, while Chinese viruses mainly fall into two families with strongly linked 'Wu' or 'Li' alleles at EBNA2 and EBNA3A/B/C, Japanese viruses all have the consensus Wu EBNA2 allele but fall into two families at EBNA3A/B/C. One family has variant Li-like sequences at EBNA3A and 3B and the consensus Li sequence at EBNA3C; the other family has variant Wu-like sequences at EBNA3A, variants of a low frequency Chinese allele 'Sp' at EBNA3B and a consensus Sp sequence at EBNA3C. Thus, EBNA3A/B/C allelotypes clearly distinguish Japanese from Chinese strains. Interestingly, most Japanese viruses also lack those immune-escape mutations in the HLA-A11 epitope-encoding region of EBNA3B that are so characteristic of viruses from the highly A11-positive Chinese population. Control donor-derived and T/NK-LPD-derived strains were similarly distributed across allelotypes and, by using allelic polymorphisms to track virus strains in patients pre- and post-haematopoietic stem-cell transplant, we show that a single strain can induce both T/NK-LPD and B-cell-lymphoproliferative disease in the same patient.

Pharmacogenetics-Based Warfarin Dosing in Patients With Cardiac Valve Replacement: The Effects of CYP2C9 and VKORC1 Gene Polymorphisms.

PubMed

Farzamikia, Negin; Sakhinia, Ebrahim; Afrasiabirad, Abbas

2017-12-22

Many lines of evidence suggest that warfarin dosing variability is significantly associated with cytochrome P450 2C9 (CYP2C9) and vitamin K epoxide reductase complex subunit 1 (VKORC1) variant alleles. Therefore, we investigated the influence of CYP2C9*2 (430C/T), *3 (1075A/C) and VKORC1 (-1639G/A) polymorphisms on warfarin dose requirements in patients who underwent cardiac valve surgery during the postoperative period.A total of 100 patients with heart valve replacement who had a prescribed target international normalized ratio (INR) range of 2-3 were enrolled in the study. Genotyping of CYP2C9 and VKORC1 was carried out using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. The demographic and clinical data were collected using a precodified questionnaire and clinical examination and then were analyzed.Our findings revealed that the prevalence of CYP2C9 *2, *3 and VKORC1 -1639A alleles in patients were 10.5%, 39%, and 48%, respectively. We also found that patients with CYP2C9 *1 and VKORC1 -1639G alleles required the highest dosages of warfarin, while the carriers of CYP2C9 variant *2 and *3 alleles and VKORC1 -1639A required less warfarin. Univariate regression analysis showed that age and presence of CYP2C9 *2 allele significantly influenced the daily warfarin dose requirement. Our findings provide additional evidence to support the hypothesis that CYP2C9*2 (430C/T), *3 (1075A/C) and VKORC1 (-1639G/A) polymorphisms explain a considerable proportion of interindividual variability in warfarin dose. Therefore, testing for these variants might be helpful for adjusting patient warfarin dosage to an effective and safe level. © American Society for Clinical Pathology 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

SLCO1B1 polymorphism is not associated with risk of statin-induced myalgia/myopathy in a Czech population.

PubMed

Hubáček, Jaroslav A; Dlouhá, Dana; Adámková, Vera; Zlatohlavek, Lukáš; Viklický, Ondřej; Hrubá, Petra; Češka, Richard; Vrablík, Michal

2015-05-20

Gene SLCO1B1, encoding solute organic anionic transport polypeptide OATP1B1, belongs to the group of candidates potentially influencing statin treatment safety. OATP1B1 regulates (not only) the hepatic uptake of statins. Its genetic variation was described as an important predictor of statin-associated myopathy in a cohort of patients treated with a maximum dose of simvastatin. However, the impact of SLCO1B1 gene polymorphism on this risk in patients treated with other statins or lower doses of simvastatin needs to be assessed. Therefore, we performed the present study. SLCO1B1 tagging rs4363657 polymorphism was analyzed in 2 groups of patients with dyslipidemia (treated with simvastatin or atorvastatin, 10 or 20 mg per day), subgroup with statin-induced myalgia (N=286), and subgroup (N=707) without myalgia/myopathy, and in 2301 population controls without lipid-lowering treatment. Frequency of the individual genotypes in patients with myalgia/myopathy (TT=62.3%, CT=34.5%, CC=2.8%) did not significantly differ (both P values over 0.19) from that in patients without muscle symptoms (TT=61.4%, CT=32.9%, CC=5.7%) or from the population controls (TT=63.9%, CT=32.5%, CC=3.6%). Null results were also obtained for the dominant and recessive models of the analysis. In Czech patients treated with low statin doses, there is no association between SLCO1B1 gene polymorphism and risk of myalgia/myopathy.

SLCO1B1 Polymorphism is not associated with Risk of Statin-Induced Myalgia/Myopathy in a Czech Population

PubMed Central

Hubáček, Jaroslav A.; Dlouhá, Dana; Adámková, Vera; Zlatohlávek, Lukáš; Viklický, Ondřej; Hrubá, Petra; Češka, Richard; Vrablík, Michal

2015-01-01

Background Gene SLCO1B1, encoding solute organic anionic transport polypeptide OATP1B1, belongs to the group of candidates potentially influencing statin treatment safety. OATP1B1 regulates (not only) the hepatic uptake of statins. Its genetic variation was described as an important predictor of statin-associated myopathy in a cohort of patients treated with a maximum dose of simvastatin. However, the impact of SLCO1B1 gene polymorphism on this risk in patients treated with other statins or lower doses of simvastatin needs to be assessed. Therefore, we performed the present study. Material/Methods SLCO1B1 tagging rs4363657 polymorphism was analyzed in 2 groups of patients with dyslipidemia (treated with simvastatin or atorvastatin, 10 or 20 mg per day), subgroup with statin-induced myalgia (N=286), and subgroup (N=707) without myalgia/myopathy, and in 2301 population controls without lipid-lowering treatment. Results Frequency of the individual genotypes in patients with myalgia/myopathy (TT=62.3%, CT=34.5%, CC=2.8%) did not significantly differ (both P values over 0.19) from that in patients without muscle symptoms (TT=61.4%, CT=32.9%, CC=5.7%) or from the population controls (TT=63.9%, CT=32.5%, CC=3.6%). Null results were also obtained for the dominant and recessive models of the analysis. Conclusions In Czech patients treated with low statin doses, there is no association between SLCO1B1 gene polymorphism and risk of myalgia/myopathy. PMID:25992810

Reengineering ribosome export.

PubMed

Lo, Kai-Yin; Johnson, Arlen W

2009-03-01

Large cargoes require multiple receptors for efficient transport through the nuclear pore complex. The 60S ribosomal subunit is one of the bulkiest transport cargoes, and in yeast three different receptors, Crm1, Mex67/Mtr2, and Arx1, collaborate in its export. However, only Crm1, recruited by the adapter Nmd3, appears to be conserved for 60S export in higher eukaryotes. We asked if export of the large subunit requires specific receptors. We made protein fusions between mutant Nmd3 and various export receptors. Surprisingly, fusions of Mex67, the tRNA exportin Los1, Mtr2, Cse1, or Msn5 to Nmd3, lacking its Crm1-dependent nuclear export signal (NES), all functioned in export. Furthermore, these chimeric proteins supported 60S export even in the presence of the Crm1 inhibitor leptomycin B, indicating that export was now independent of Crm1. These results suggest that there is not a requirement for a specific export receptor for the large subunit, as recruitment of any receptor will suffice. Finally we show that the addition of an NES directly to the 60S ribosomal subunit protein Rpl3 promotes export. These results imply remarkable flexibility in the export pathway for the 60S subunit and help explain how different export receptors could have evolved in different eukaryotic lineages.

Reengineering Ribosome Export

PubMed Central

Lo, Kai-Yin

2009-01-01

Large cargoes require multiple receptors for efficient transport through the nuclear pore complex. The 60S ribosomal subunit is one of the bulkiest transport cargoes, and in yeast three different receptors, Crm1, Mex67/Mtr2, and Arx1, collaborate in its export. However, only Crm1, recruited by the adapter Nmd3, appears to be conserved for 60S export in higher eukaryotes. We asked if export of the large subunit requires specific receptors. We made protein fusions between mutant Nmd3 and various export receptors. Surprisingly, fusions of Mex67, the tRNA exportin Los1, Mtr2, Cse1, or Msn5 to Nmd3, lacking its Crm1-dependent nuclear export signal (NES), all functioned in export. Furthermore, these chimeric proteins supported 60S export even in the presence of the Crm1 inhibitor leptomycin B, indicating that export was now independent of Crm1. These results suggest that there is not a requirement for a specific export receptor for the large subunit, as recruitment of any receptor will suffice. Finally we show that the addition of an NES directly to the 60S ribosomal subunit protein Rpl3 promotes export. These results imply remarkable flexibility in the export pathway for the 60S subunit and help explain how different export receptors could have evolved in different eukaryotic lineages. PMID:19144820

The N-methyl-D-aspartate receptor subunits NR2A and NR2B bind to the SH2 domains of phospholipase C-gamma.

PubMed

Gurd, J W; Bissoon, N

1997-08-01

The NMDA receptor has recently been found to be phosphorylated on tyrosine. To assess the possible connection between tyrosine phosphorylation of the NMDA receptor and signaling pathways in the postsynaptic cell, we have investigated the relationship between tyrosine phosphorylation and the binding of NMDA receptor subunits to the SH2 domains of phospholipase C-gamma (PLC-gamma). A glutathione S-transferase (GST) fusion protein containing both the N- and the C-proximal SH2 domains of PLC-gamma was bound to glutathione-agarose and reacted with synaptic junctional proteins and glycoproteins. Tyrosine-phosphorylated PSD-GP180, which has been identified as the NR2B subunit of the NMDA receptor, bound to the SH2-agarose beads in a phosphorylation-dependent fashion. Immunoblot analysis with antibodies specific for individual NMDA receptor subunits showed that both NR2A and NR2B subunits bound to the SH2-agarose. No binding occurred to GST-agarose lacking an associated SH2 domain, indicating that binding was specific for the SH2 domains. The binding of receptor subunits increased after the incubation of synaptic junctions with ATP and decreased after treatment of synaptic junctions with exogenous protein tyrosine phosphatase. Immunoprecipitation experiments confirmed that NR2A and NR2B were phosphorylated on tyrosine and further that tyrosine phosphorylation of each of the subunits was increased after incubation with ATP. The results demonstrate that NMDA receptor subunits NR2A and NR2B will bind to the SH2 domains of PLC-gamma and that isolated synaptic junctions contain endogenous protein tyrosine kinase(s) that can phosphorylate both NR2A and NR2B receptor subunits, and suggest that interaction of the tyrosine-phosphorylated NMDA receptor with proteins that contain SH2 domains may serve to link it to signaling pathways in the postsynaptic cell.

Structure-function analysis and genetic interactions of the SmG, SmE, and SmF subunits of the yeast Sm protein ring.

PubMed

Schwer, Beate; Kruchten, Joshua; Shuman, Stewart

2016-09-01

A seven-subunit Sm protein ring forms a core scaffold of the U1, U2, U4, and U5 snRNPs that direct pre-mRNA splicing. Using human snRNP structures to guide mutagenesis in Saccharomyces cerevisiae, we gained new insights into structure-function relationships of the SmG, SmE, and SmF subunits. An alanine scan of 19 conserved amino acids of these three proteins, comprising the Sm RNA binding sites or inter-subunit interfaces, revealed that, with the exception of Arg74 in SmF, none are essential for yeast growth. Yet, for SmG, SmE, and SmF, as for many components of the yeast spliceosome, the effects of perturbing protein-RNA and protein-protein interactions are masked by built-in functional redundancies of the splicing machine. For example, tests for genetic interactions with non-Sm splicing factors showed that many benign mutations of SmG, SmE, and SmF (and of SmB and SmD3) were synthetically lethal with null alleles of U2 snRNP subunits Lea1 and Msl1. Tests of pairwise combinations of SmG, SmE, SmF, SmB, and SmD3 alleles highlighted the inherent redundancies within the Sm ring, whereby simultaneous mutations of the RNA binding sites of any two of the Sm subunits are lethal. Our results suggest that six intact RNA binding sites in the Sm ring suffice for function but five sites may not. © 2016 Schwer et al.; Published by Cold Spring Harbor Laboratory Press for the RNA Society.

Stimulatory and inhibitory effects of PKC isozymes are mediated by serine/threonine PKC sites of the Cav2.3α1 subunits.

PubMed

Rajagopal, Senthilkumar; Burton, Brittney K; Fields, Blanche L; El, India O; Kamatchi, Ganesan L

2017-05-01

Protein kinase C (PKC) isozymes modulate voltage-gated calcium (Ca v ) currents through Ca v 2.2 and Ca v 2.3 channels by targeting serine/threonine (Ser/Thr) phosphorylation sites of Ca v α 1 subunits. Stimulatory (Thr-422, Ser-2108 and Ser-2132) and inhibitory (Ser-425) sites were identified in the Ca v 2.2α 1 subunits to PKCs βII and ε. In the current study, we investigated if the homologous sites of Ca v 2.3α 1 subunits (stimulatory: Thr-365, Ser-1995 and Ser-2011; inhibitory: Ser-369) behaved in similar manner. Several Ala and Asp mutants were constructed in Ca v 2.3α 1 subunits in such a way that the Ser/Thr sites can be examined in isolation. These mutants or WT Ca v 2.3α 1 along with auxiliary β 1b and α 2 /δ subunits were expressed in Xenopus oocytes and the effects of PKCs βII and ε studied on the barium current (I Ba ). Among these sites, stimulatory Thr-365 and Ser-1995 and inhibitory Ser-369 behaved similar to their homologs in Ca v 2.2α 1 subunits. Furthermore PKCs produced neither stimulation nor inhibition when stimulatory Thr-365 or Ser-1995 and inhibitory Ser-369 were present together. However, the PKCs potentiated the I Ba when two stimulatory sites, Thr-365 and Ser-1995 were present together, thus overcoming the inhibitory effect of Ser-369. Taken together net PKC effect may be the difference between the responses of the stimulatory and inhibitory sites. Copyright © 2017 Elsevier Inc. All rights reserved.

Discovery of a novel microsporidium in laboratory colonies of Mediterranean cricket Gryllus bimaculatus (Orthoptera: Gryllidae): Microsporidium grylli sp. nov.

PubMed

Tokarev, Yuri S; Peat, Katy M; Malysh, Julia M; Senderskiy, Igor V

2018-06-21

A microsporidium was found in a Mediterranean cricket Gryllus bimaculatus from a pet market in the UK and a lab stock at the Moscow Zoo (originating from London Zoo). The spores were ovoid, uninucleate, 6.3 × 3.7 μm in size (unfixed), in packets by of 8, 16, or 32. The spores were easily discharged upon dessication or slight mechanical pressure. The polar tube was isofilar, with 15-16 coils arranged in 1-2 rows. The polaroplast was composed of thin lamellae and occupied about one third of the spore volume. The endospore was 200 nm thick, thinning over the anchoring disc. The exospore was thin, uniform, and with no ornamentation. Phylogenetics based upon small subunit ribosomal RNA (Genbank accession # MG663123) and RNA polymerase II largest subunit (# MG664544) genes placed the parasite at the base of the Trachipleistophora/Vavraia lineage. The RPB1 locus was polymorphic but similar genetic structure and identical clones were found in both isolates, confirming their common geographic origin. Due to in insufficient ultrastructural data and prominent divergence from described species, the parasite is provisionally placed to the collective taxon Microsporidium.

Mutations in CUL4B, which encodes a ubiquitin E3 ligase subunit, cause an X-linked mental retardation syndrome associated with aggressive outbursts, seizures, relative macrocephaly, central obesity, hypogonadism, pes cavus, and tremor.

PubMed

Tarpey, Patrick S; Raymond, F Lucy; O'Meara, Sarah; Edkins, Sarah; Teague, Jon; Butler, Adam; Dicks, Ed; Stevens, Claire; Tofts, Calli; Avis, Tim; Barthorpe, Syd; Buck, Gemma; Cole, Jennifer; Gray, Kristian; Halliday, Kelly; Harrison, Rachel; Hills, Katy; Jenkinson, Andrew; Jones, David; Menzies, Andrew; Mironenko, Tatiana; Perry, Janet; Raine, Keiran; Richardson, David; Shepherd, Rebecca; Small, Alexandra; Varian, Jennifer; West, Sofie; Widaa, Sara; Mallya, Uma; Moon, Jenny; Luo, Ying; Holder, Susan; Smithson, Sarah F; Hurst, Jane A; Clayton-Smith, Jill; Kerr, Bronwyn; Boyle, Jackie; Shaw, Marie; Vandeleur, Lucianne; Rodriguez, Jayson; Slaugh, Rachel; Easton, Douglas F; Wooster, Richard; Bobrow, Martin; Srivastava, Anand K; Stevenson, Roger E; Schwartz, Charles E; Turner, Gillian; Gecz, Jozef; Futreal, P Andrew; Stratton, Michael R; Partington, Michael

2007-02-01

We have identified three truncating, two splice-site, and three missense variants at conserved amino acids in the CUL4B gene on Xq24 in 8 of 250 families with X-linked mental retardation (XLMR). During affected subjects' adolescence, a syndrome emerged with delayed puberty, hypogonadism, relative macrocephaly, moderate short stature, central obesity, unprovoked aggressive outbursts, fine intention tremor, pes cavus, and abnormalities of the toes. This syndrome was first described by Cazebas et al., in a family that was included in our study and that carried a CUL4B missense variant. CUL4B is a ubiquitin E3 ligase subunit implicated in the regulation of several biological processes, and CUL4B is the first XLMR gene that encodes an E3 ubiquitin ligase. The relatively high frequency of CUL4B mutations in this series indicates that it is one of the most commonly mutated genes underlying XLMR and suggests that its introduction into clinical diagnostics should be a high priority.

Differential plasma membrane targeting of voltage-dependent calcium channel subunits expressed in a polarized epithelial cell line

PubMed Central

Brice, Nicola L; Dolphin, Annette C

1999-01-01

Voltage-dependent calcium channels (VDCCs) show a highly non-uniform distribution in many cell types, including neurons and other polarized secretory cells. We have examined whether this can be mimicked in a polarized epithelial cell line (Madin-Darby canine kidney), which has been used extensively to study the targeting of proteins. We expressed the VDCC α1A, α1B or α1C subunits either alone or in combination with accessory subunits α2-δ and the different β subunits, and examined their localization immunocytochemically. An α1 subunit was only targeted to the plasma membrane if co-expressed with the accessory subunits. The combination α1C/α2-δ and all β subunits was always localized predominantly to the basolateral membrane. It has been suggested that this is equivalent to somatodendritic targeting in neurons. In contrast, the α1B subunit was expressed at the apical membrane with all the accessory subunit combinations, by 24 h after microinjection. This membrane destination shows some parallels with axonal targeting in neurons. The α1A subunit was consistently observed at the apical membrane in the combinations α1A/α2-δ/β1b or β4. In contrast, when co-expressed with α2-δ/β2a, α1A was clearly targeted to the basolateral membrane. In conclusion, the VDCC α1 subunit appears to be the primary determinant for targeting the VDCC complex, but the β subunit can modify this destination, particularly for α1A. PMID:10066897

The genetic polymorphism and expression profiles of NLRP3 inflammasome in patients with chronic myeloid leukemia.

PubMed

Zhang, Amin; Yu, Jie; Yan, Shuxin; Zhao, Xia; Chen, Chen; Zhou, Ying; Zhao, Xueyun; Hua, Mingqiang; Wang, Ruiqing; Zhang, Chen; Zhong, Chaoqin; He, Na; Ji, Chunyan; Ma, Daoxin

2018-01-01

NLRP3 inflammasome has been recently reported as an important risk factor in the development of cancer. But the relationship between polymorphisms of NLRP3 inflammasome related genes and chronic myeloid leukemia (CML) is rarely reported. Therefore, the aim of the present study was to investigate the association of five genetic polymorphisms (NLRP3, IL-1β, IL-18, CARD8 and NF-κB) in 267 CML patients and 344 healthy controls. We found that the AT genotype of CARD8 (rs2043211) was significantly higher compared to TT genotype in high and intermediate risk CML patients. IL-1β (rs16944) polymorphism in early molecular response at 6 months was marginally different, with more GG and less AA genotype in BCR-ABL IS >1% group. IL-18 (rs1946518) polymorphism was significantly different with more GG genotype in BCR-ABL IS >1% group at 6 months. We also demonstrated that WBC count of newly diagnosed patients carrying AG genotype was significantly higher than that of GG or AA genotype of IL-1β (rs16944). The onset age of patients carrying ins/ins genotype of NF-κB (rs28362491) was significantly older than that of ins/del and del/del genotype. Moreover, IL-1β or NLRP3 mRNA expression was decreased and IL-18 mRNA expression was increased significantly in CML patients compared with controls. In conclusion, the genetic polymorphisms of NLRP3 inflammasome may be served as potential predictors for CML. Copyright © 2017 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.

Protective Immunity to Ricin Toxin Conferred by Antibodies against the Toxin’s Binding Subunit (RTB)

PubMed Central

Yermakova, Anastasiya; Mantis, Nicholas J.

2011-01-01

The B subunit (RTB) of ricin toxin is a galactose-/N-acetyl galactosamine-specific lectin that promotes attachment and entry of ricin into host cells. RTB is also the archetype of the so-called R-type lectin family, whose members include haemagglutinins of botulinum neurotoxin (BoNT) progenitor toxins, as well as the binding subunits of cytolethal distending toxins. Although RTB is an appealing subunit vaccine candidate, as well as a potential target for immunotherapeutics, the degree to which RTB immunization elicits protective antibodies against ricin toxin remains unresolved. To address this issue, groups of mice were immunized with RTB and then challenged with 5xLD50s of ricin administered intraperitoneally. Despite high RTB-specific serum antibody titers, groups of RTB immunized mice were only partially immune to ricin challenge. Analysis of a collection of RTB-specific B cell hybridomas suggested that only a small fraction of antibodies against RTB have demonstrable neutralizing activity. Two RTB-specific neutralizing monoclonal IgG1 antibodies, 24B11 and SylH3, when passively administered to mice, were sufficient to protect the animals against a 5xLD50 dose of ricin. Both 24B11 and SylH3 blocked ricin attachment to terminal galactose residues and prevented toxin binding to the surfaces of bone marrow-derived macrophages (BMM), suggesting that they function by steric hindrance and recognize epitopes located on RTB’s carbohydrate recognition sub-domains (1α or 2γ). These data raise the possibility of using specific RTB sub-domains, rather than RTB itself, as antigens to more efficiently elicit neutralizing antibodies and protective immunity against ricin. PMID:21872634

The effect of cytochrome P2C19 and interleukin-1 polymorphisms on H. pylori eradication rate of 1-week triple therapy with omeprazole or rabeprazole, amoxycillin and clarithromycin in Chinese people.

PubMed

Zhang, L; Mei, Q; Li, Q S; Hu, Y M; Xu, J M

2010-12-01

Genetic polymorphism of interleukin (IL)-1β and IL-1 receptor antagonist (IL-1rα) are associated with efficacy of acid suppression, whereas cytochrome P (CYP) 2C19 polymorphism influences the metabolism of proton pump inhibitor family. Thus, CYP2C19 and IL-1 polymorphisms may affect the efficacy of H. pylori eradication therapy. We compared the efficacies of omeprazole and rabeprazole on eradication of H. pylori in relation to CYP2C19, IL-1B and IL-1RN genotypes in Chinese people. Two hundred and forty Chinese with peptic ulcer disease were randomly assigned to the following regimens: amoxicillin and clarithromycin together with omeprazole (OAC) or rabeprazole (RAC). CYP2C19*2 and *3, IL1B-511, IL1B-31, IL1B+ 3954 and intron 2 of the IL-1RN genotypes were analyzed by polymerase chain reaction-restriction fragment length polymorphism. The intention-to-treat-based cure rate of the OAC regimen was significantly lower than that of the RAC regimen in the CYP2C19 wild-type homozygotes (P = 0·014). No significant differences in the cure rates were observed among the IL-1RN and the IL-1B genotype groups. The rabeprazole-based triple regimen was better than the omeprazole in Chinese patients with the CYP2C19 extensive metabolizer genotype. The effectiveness of the PPI/AC regimen is unrelated to IL-1B and IL1-RN genetic polymorphism. © 2010 Blackwell Publishing Ltd.

Ghrelin upregulates the phosphorylation of the GluN2B subunit of the NMDA receptor by activating GHSR1a and Fyn in the rat hippocampus.

PubMed

Berrout, Liza; Isokawa, Masako

2018-01-01

Ghrelin and its receptor GHSR1a have been shown to exert numerous physiological functions in the brain, in addition to the well-established orexigenic role in the hypothalamus. Earlier work indicated that ghrelin stimulated the phosphorylation of the GluN1 subunit of the NMDA receptor (NMDAR) and enhanced synaptic transmission in the hippocampus. In the present study, we report that the exogenous application of ghrelin increased GluN2B phosphorylation. This increase was independent of GluN2B subunit activity or NMDAR channel activity. However, it depended on the activation of GHSR1a and Fyn as it was blocked by D-Lys3-GHRP-6 and PP2, respectively. Inhibitors for G-protein-regulated second messengers, such as Rp-cAMP, H89, TBB, ryanodine, and thapsigargin, unexpectedly enhanced GluN2B phosphorylation, suggesting that cAMP, PKA, casein kinase II, and cytosolic calcium signaling may oppose to the effect of ghrelin on the phosphorylation of GluN2B. Our findings suggest that 1) GluN2B is likely a molecular target of ghrelin and GHSR1a-driven signaling cascades, and 2) the ghrelin-mediated phosphorylation of GluN2B depends on Fyn activation under complex negative regulation by other second messengers. Copyright © 2017 Elsevier B.V. All rights reserved.

Alternative haplotypes of antigen processing genes in zebrafish diverged early in vertebrate evolution

PubMed Central

McConnell, Sean C.; Hernandez, Kyle M.; Wcisel, Dustin J.; Kettleborough, Ross N.; Stemple, Derek L.; Andrade, Jorge; de Jong, Jill L. O.

2016-01-01

Antigen processing and presentation genes found within the MHC are among the most highly polymorphic genes of vertebrate genomes, providing populations with diverse immune responses to a wide array of pathogens. Here, we describe transcriptome, exome, and whole-genome sequencing of clonal zebrafish, uncovering the most extensive diversity within the antigen processing and presentation genes of any species yet examined. Our CG2 clonal zebrafish assembly provides genomic context within a remarkably divergent haplotype of the core MHC region on chromosome 19 for six expressed genes not found in the zebrafish reference genome: mhc1uga, proteasome-β 9b (psmb9b), psmb8f, and previously unknown genes psmb13b, tap2d, and tap2e. We identify ancient lineages for Psmb13 within a proteasome branch previously thought to be monomorphic and provide evidence of substantial lineage diversity within each of three major trifurcations of catalytic-type proteasome subunits in vertebrates: Psmb5/Psmb8/Psmb11, Psmb6/Psmb9/Psmb12, and Psmb7/Psmb10/Psmb13. Strikingly, nearby tap2 and MHC class I genes also retain ancient sequence lineages, indicating that alternative lineages may have been preserved throughout the entire MHC pathway since early diversification of the adaptive immune system ∼500 Mya. Furthermore, polymorphisms within the three MHC pathway steps (antigen cleavage, transport, and presentation) are each predicted to alter peptide specificity. Lastly, comparative analysis shows that antigen processing gene diversity is far more extensive than previously realized (with ancient coelacanth psmb8 lineages, shark psmb13, and tap2t and psmb10 outside the teleost MHC), implying distinct immune functions and conserved roles in shaping MHC pathway evolution throughout vertebrates. PMID:27493218

Polymorphisms in the phosducin (PDC) gene on chromosome 1q25-32

DOE Office of Scientific and Technical Information (OSTI.GOV)

Humphries, P.; Mansergh, F.C.; Farrar, G.J.

1994-09-01

Phosducin (33 kDa protein or MEKA) is a principal water-soluble phosphoprotein in the rod and cone photoreceptor cells and pinealocytes. This protein modulates the phototransduction cascade by binding to the beta and gamma subunit complexes of transducin. The PDC gene has been mapped to 1q25-32, the region of linkage of two hereditary retinal degenerative disorders; autosomal dominant juvenile-onset open-angle glaucoma and one form of autosomal recessive RP. Using previously published sequence data, PCR primers were designed to amplify the coding and 5{prime} flanking regions of the PDC gene. Direct sequencing revealed three polymorphisms in the 5{prime} flanking region, two ofmore » which were in regions highly homologous between humans and mice. Analysis of the polymorphisms was then extended to larger population samples using SSCPE and denaturing gel analysis. The first polymorphism PDC1 resulted from an insertion of a G residue at position -653/4. Allele frequencies were determined to be 0.51 (insG) and 0.49 (normal) giving a PIC value of 0.50. A deletion of a T residue at position -488 was the basis of the PDC2 polymorphism with allele frequencies of 0.88 (normal) and 0.12 (delT) and a PIC value of 0.21. Interestingly, the allele with an inserted G residue in PDC1 always segregrated with the deleted T allele in PDC2. The third polymorphism PDC3 was caused by a T or G residue at position -1083. Allele frequencies of 0.26 (G residue) and 0.74 (T residue) were determined from an analysis of 80 individuals with an overall PIC value of 0.39. The identification of these three polymorphisms in the PDC gene will be useful for future genetic linkage studies of chromosome 1q in inherited retinopathies.« less

Sucrose regulation of ADP-glucose pyrophosphorylase subunit genes transcript levels in leaves and fruits

NASA Technical Reports Server (NTRS)

Li, Xiangyang; Xing, Jinpeng; Gianfagna, Thomas J.; Janes, Harry W.

2002-01-01

ADP-glucose pyrophosphorylase (AGPase, EC2.7.7.27) is a key regulatory enzyme in starch biosynthesis. The enzyme is a heterotetramer with two S and two B subunits. In tomato, there are three multiple forms of the S subunit gene. Agp S1, S2 and B are highly expressed in fruit from 10 to 25 days after anthesis. Agp S3 is only weakly expressed in fruit. Sucrose significantly elevates expression of Agp S1, S2 and B in both leaves and fruits. Agp S1 exhibits the highest degree of regulation by sucrose. In fact, sucrose may be required for Agp S1 expression. For excised leaves incubated in water, no transcripts for Agp S1 could be detected in the absence of sucrose, whereas it took up to 16 h in water before transcripts were no longer detectable for Agp S2 and B. Neither Agp S3 nor the tubulin gene is affected by sucrose, demonstrating that this response is specifically regulated by a carbohydrate metabolic signal, and is not due to a general increase in metabolism caused by sucrose treatment. Truncated versions of the promoter for Agp S1 indicate that a specific region 1.3-3.0 kb upstream from the transcription site is responsible for sucrose sensitivity. This region of the S1 promoter contains several cis-acting elements present in the promoters of other genes that are also regulated by sucrose. c2002 Elsevier Science Ireland Ltd. All rights reserved.

A New Primer Set to Amplify the Mitochondrial Cytochrome C Oxidase Subunit I (COI) Gene in the DHA-Rich Microalgae, the Genus Aurantiochytrium.

PubMed

Nishitani, Goh; Yoshida, Masaki

2018-06-01

This study was performed in order to develop a primer set for mitochondrial cytochrome c oxidase subunit I (COI) in the DHA-rich microalgae of the genus Aurantiochytrium. The performance of the primer set was tested using 12 Aurantiochytrium strains and other thraustochytrid species. There were no genetic polymorphisms in the mitochondrial sequences from the Aurantiochytrium strains, in contrast to the nuclear 18S rRNA gene sequence. This newly developed primer set amplified sequences from Aurantiochytrium and closely related genera, and may be useful for species identification and clarifying the genetic diversity of Aurantiochytrium in the field.

Similarities in transcription factor IIIC subunits that bind to the posterior regions of internal promoters for RNA polymerase III.

PubMed

Matsutani, Sachiko

2004-08-09

In eukaryotes, RNA polymerase III (RNAP III) transcribes the genes for small RNAs like tRNAs, 5S rRNA, and several viral RNAs, and short interspersed repetitive elements (SINEs). The genes for these RNAs and SINEs have internal promoters that consist of two regions. These two regions are called the A and B blocks. The multisubunit transcription factor TFIIIC is required for transcription initiation of RNAP III; in transcription of tRNAs, the B-block binding subunit of TFIIIC recognizes a promoter. Although internal promoter sequences are conserved in eukaryotes, no evidence of homology between the B-block binding subunits of vertebrates and yeasts has been reported previously. Here, I reported the results of PSI-BLAST searches using the B-block binding subunits of human and Shizosacchromyces pombe as queries, showing that the same Arabidopsis proteins were hit with low E-values in both searches. Comparison of the convergent iterative alignments obtained by these PSI-BLAST searches revealed that the vertebrate, yeast, and Arabidopsis proteins have similarities in their N-terminal one-third regions. In these regions, there were three domains with conserved sequence similarities, one located in the N-terminal end region. The N-terminal end region of the B-block binding subunit of Saccharomyces cerevisiae is tentatively identified as a HMG box, which is the DNA binding motif. Although I compared the alignment of the N-terminal end regions of the B-block binding subunits, and their homologs, with that of the HMG boxes, it is not clear whether they are related. Molecular phylogenetic analyses using the small subunit rRNA and ubiquitous proteins like actin and alpha-tubulin, show that fungi are more closely related to animals than either is to plants. Interestingly, the results obtained in this study show that, with respect to the B-block binding subunits of TFIIICs, animals appear to be evolutionarily closer to plants than to fungi.

Influence of Coulombic repulsion on the dissociation pathways and energetics of multiprotein complexes in the gas phase.

PubMed

Sinelnikov, Igor; Kitova, Elena N; Klassen, John S

2007-04-01

Thermal dissociation experiments, implemented with blackbody infrared radiative dissociation and Fourier-transform ion cyclotron resonance mass spectrometry, are performed on gaseous protonated and deprotonated ions of the homopentameric B subunits of Shiga toxin 1 (Stx1 B5) and Shiga toxin 2 (Stx2 B5) and the homotetramer streptavidin (S4). Dissociation of the gaseous, multisubunit complexes proceeds predominantly by the loss of a single subunit. Notably, the fractional partitioning of charge between the product ions, i.e., the leaving subunit and the resulting multimer, for a given complex is, within error, constant over the range of charge states investigated. The Arrhenius activation parameters (E(a), A) measured for the loss of subunit decrease with increasing charge state of the complex. However, the parameters for the protonated and deprotonated ions, with the same number of charges, are indistinguishable. The influence of the complex charge state on the dissociation pathways and the magnitude of the dissociation E(a) are modeled theoretically with the discrete charge droplet model (DCDM) and the protein structure model (PSM), wherein the structure of the subunits is considered. Importantly, the major subunit charge states observed experimentally for the Stx1 B5(n+/-) ions correspond to the minimum energy charge distribution predicted by DCDM and PSM assuming a late dissociative transition-state (TS); while for structurally-related Stx2 B5(n+) ions, the experimental charge distribution corresponds to an early TS. It is proposed that the lateness of the TS is related, in part, to the degree of unfolding of the leaving subunit, with Stx1 B being more unfolded than Stx2 B. PSM, incorporating significant subunit unfolding is necessary to account for the product ions observed for the S4(n+) ions. The contribution of Coulombic repulsion to the dissociation E(a) is quantified and the intrinsic activation energy is estimated for the first time.

Association between variants in or near PNPLA3, GCKR, and PPP1R3B with ultrasound-defined steatosis based on data from the third National Health and Nutrition Examination Survey.

PubMed

Hernaez, Ruben; McLean, Jody; Lazo, Mariana; Brancati, Frederick L; Hirschhorn, Joel N; Borecki, Ingrid B; Harris, Tamara B; Nguyen, Thutrang; Kamel, Ihab R; Bonekamp, Susanne; Eberhardt, Mark S; Clark, Jeanne M; Kao, Wen Hong Linda; Speliotes, Elizabeth K

2013-09-01

A genome-wide association study associated 5 genetic variants with hepatic steatosis (identified by computerized tomography) in individuals of European ancestry. We investigated whether these variants were associated with measures of hepatic steatosis (HS) in non-Hispanic white (NHW), non-Hispanic black, and Mexican American (MA) participants in the US population-based National Health and Nutrition Examination Survey III, phase 2. We analyzed data from 4804 adults (1825 NHW, 1442 non-Hispanic black, and 1537 MA; 51.7% women; mean age at examination, 42.5 y); the weighted prevalence of HS was 37.3%. We investigated whether ultrasound-measured HS, with and without increased levels of alanine aminotransferase (ALT), or level of ALT alone, was associated with rs738409 (patatin-like phospholipase domain-containing protein 3 [PNPLA3]), rs2228603 (neurocan [NCAN]), rs12137855 (lysophospholipase-like 1), rs780094 (glucokinase regulatory protein [GCKR]), and rs4240624 (protein phosphatase 1, regulatory subunit 3b [PPP1R3B]) using regression modeling in an additive genetic model, controlling for age, age-squared, sex, and alcohol consumption. The G allele of rs738409 (PNPLA3) and the T allele of rs780094 (GCKR) were associated with HS with a high level of ALT (odds ratio [OR], 1.36; P = .01; and OR, 1.30; P = .03, respectively). The A allele of rs4240624 (PPP1R3B) and the T allele of rs2228603 (NCAN) were associated with HS (OR, 1.28; P = .03; and OR, 1.40; P = .04, respectively). Variants of PNPLA3 and NCAN were associated with ALT level among all 3 ancestries. Some single-nucleotide polymorphisms were associated with particular races or ethnicities: variants in PNPLA3, NCAN, GCKR, and PPP1R3B were associated with NHW and variants in PNPLA3 were associated with MA. No variants were associated with NHB. We used data from the National Health and Nutrition Examination Survey III to validate the association between rs738409 (PNPLA3), rs780094 (GCKR), and rs4240624 (PPP1R3B) with HS, with or without increased levels of ALT, among 3 different ancestries. Some, but not all, associations between variants in NCAN, lysophospholipase-like 1, GCKR, and PPP1R3B with HS (with and without increased ALT level) were significant within subpopulations. Copyright © 2013 AGA Institute. Published by Elsevier Inc. All rights reserved.

Ada protein-RNA polymerase sigma subunit interaction and alpha subunit-promoter DNA interaction are necessary at different steps in transcription initiation at the Escherichia coli Ada and aidB promoters.

PubMed

Landini, P; Bown, J A; Volkert, M R; Busby, S J

1998-05-22

The methylated form of the Ada protein (meAda) binds the ada and aidB promoters between 60 and 40 base pairs upstream from the transcription start and activates transcription of the Escherichia coli ada and aidB genes. This region is also a binding site for the alpha subunit of RNA polymerase and resembles the rrnB P1 UP element in A/T content and location relative to the core promoter. In this report, we show that deletion of the C-terminal domain of the alpha subunit severely decreases meAda-independent binding of RNA polymerase to ada and aidB, affecting transcription initiation at these promoters. We provide evidence that meAda activates transcription by direct interaction with the C-terminal domain of RNA polymerase sigma70 subunit (amino acids 574-613). Several negatively charged residues in the sigma70 C-terminal domain are important for transcription activation by meAda; in particular, a glutamic acid to valine substitution at position 575 has a dramatic effect on meAda-dependent transcription. Based on these observations, we propose that the role of the alpha subunit at ada and aidB is to allow initial binding of RNA polymerase to the promoters. However, transcription initiation is dependent on meAda-sigma70 interaction.

Proteomic analysis of Arabidopsis thaliana leaves in response to acute boron deficiency and toxicity reveals effects on photosynthesis, carbohydrate metabolism, and protein synthesis.

PubMed

Chen, Mei; Mishra, Sasmita; Heckathorn, Scott A; Frantz, Jonathan M; Krause, Charles

2014-02-15

Boron (B) stress (deficiency and toxicity) is common in plants, but as the functions of this essential micronutrient are incompletely understood, so too are the effects of B stress. To investigate mechanisms underlying B stress, we examined protein profiles in leaves of Arabidopsis thaliana plants grown under normal B (30 μM), compared to plants transferred for 60 and 84 h (i.e., before and after initial visible symptoms) in deficient (0 μM) or toxic (3 mM) levels of B. B-responsive polypeptides were sequenced by mass spectrometry, following 2D gel electrophoresis, and 1D gels and immunoblotting were used to confirm the B-responsiveness of some of these proteins. Fourteen B-responsive proteins were identified, including: 9 chloroplast proteins, 6 proteins of photosynthetic/carbohydrate metabolism (rubisco activase, OEC23, photosystem I reaction center subunit II-1, ATPase δ-subunit, glycolate oxidase, fructose bisphosphate aldolase), 6 stress proteins, and 3 proteins involved in protein synthesis (note that the 14 proteins may fall into multiple categories). Most (8) of the B-responsive proteins decreased under both B deficiency and toxicity; only 3 increased with B stress. Boron stress decreased, or had no effect on, 3 of 4 oxidative stress proteins examined, and did not affect total protein. Hence, our results indicate relatively early specific effects of B stress on chloroplasts and protein synthesis. Copyright © 2013 Elsevier GmbH. All rights reserved.

Proposal for the nomenclature of human plasminogen (PLG) polymorphism.

PubMed

Skoda, U; Bertrams, J; Dykes, D; Eiberg, H; Hobart, M; Hummel, K; Kühnl, P; Mauff, G; Nakamura, S; Nishimukai, H

1986-01-01

Since its discovery, human plasminogen (PLG) polymorphism has received widespread acceptance in population genetics and forensic haematology. Due to the large number of variant alleles described, a PLG reference typing and Plasminogen Symposium was held, at which a nomenclature proposal was inaugurated. The technology of comparing PLG variants was based on isoelectric focusing and subsequent detection by caseinolytic overlay and 'Western' blotting. Typing results permitted comparison of so far described variant designations and resulted in a new nomenclature proposal for PLG polymorphism. It is recommended that the two most common alleles found in all investigated races be called: PLG*A (previously also PLG*1) and PLG*B (previously also PLG*2), the known variants with acidic pI: PLG*A1 to *A3, intermediate variants: PLG*M1 to *M5, PLG*M5 being functionally inactive, and basic variants: PLG*B1 to *B3. For future classification of newly discovered variants, samples should be compared at any of the laboratories participating in the reference typing.

Drug metabolism and transport gene polymorphisms and efavirenz adverse effects in Brazilian HIV-positive individuals.

PubMed

de Almeida, Tailah Bernardo; de Azevedo, Marcelo Costa Velho Mendes; Pinto, Jorge Francisco da Cunha; Ferry, Fernando Rafael de Almeida; da Silva, Guilherme Almeida Rosa; de Castro, Izana Junqueira; Baker, Paxton; Tanuri, Amilcar; Haas, David W; Cardoso, Cynthia C

2018-06-03

There are limited data regarding efavirenz pharmacogenetics in admixed populations. The Brazilian population is highly admixed. In a Brazilian cohort, we sought to characterize associations between efavirenz adverse effects (all-cause and CNS) and polymorphisms in seven genes known or suspected to affect efavirenz metabolism and transport. We studied 225 HIV-positive individuals who had been prescribed efavirenz-containing regimens at a hospital in Rio de Janeiro, Brazil. Eighty-nine cases had efavirenz adverse effects, including 43 with CNS adverse effects, while 136 controls had no adverse effect of any antiretroviral after treatment for at least 6 months. A total of 67 candidate polymorphisms in ABCB1, CYP2A6, CYP2B6, CYP3A4, CYP3A5, NR1I2 and NR1I3 genes were selected for association analysis. Admixture was assessed using 28 ancestry-informative polymorphisms previously validated for the Brazilian population. Associations were evaluated with logistic regression models adjusted for sex and genetic ancestry. There was extensive African, European and Native American admixture in the cohort. Increased all-cause adverse effects were associated with the CYP2B6 genotype combination 15582CC-516TT-983TT (OR = 7.26, P = 0.003) and with the CYP2B6 slow metabolizer group 516TT or 516GT-983CT (OR = 3.10, P = 0.04). CNS adverse effects were nominally associated with CYP3A4 rs4646437 (OR = 4.63, P = 0.014), but not after adjusting for multiple comparisons. In a highly admixed Brazilian cohort, the CYP2B6 slow metabolizer genotype was associated with an increased risk of efavirenz adverse effects.

N terminus of Swr1 binds to histone H2AZ and provides a platform for subunit assembly in the chromatin remodeling complex.

PubMed

Wu, Wei-Hua; Wu, Chwen-Huey; Ladurner, Andreas; Mizuguchi, Gaku; Wei, Debbie; Xiao, Hua; Luk, Ed; Ranjan, Anand; Wu, Carl

2009-03-06

Variant histone H2AZ-containing nucleosomes are involved in the regulation of gene expression. In Saccharomyces cerevisiae, chromatin deposition of histone H2AZ is mediated by the fourteen-subunit SWR1 complex, which catalyzes ATP-dependent exchange of nucleosomal histone H2A for H2AZ. Previous work defined the role of seven SWR1 subunits (Swr1 ATPase, Swc2, Swc3, Arp6, Swc5, Yaf9, and Swc6) in maintaining complex integrity and H2AZ histone replacement activity. Here we examined the function of three additional SWR1 subunits, bromodomain containing Bdf1, actin-related protein Arp4 and Swc7, by analyzing affinity-purified mutant SWR1 complexes. We observed that depletion of Arp4 (arp4-td) substantially impaired the association of Bdf1, Yaf9, and Swc4. In contrast, loss of either Bdf1 or Swc7 had minimal effects on overall complex integrity. Furthermore, the basic H2AZ histone replacement activity of SWR1 in vitro required Arp4, but not Bdf1 or Swc7. Thus, three out of fourteen SWR1 subunits, Bdf1, Swc7, and previously noted Swc3, appear to have roles auxiliary to the basic histone replacement activity. The N-terminal region of the Swr1 ATPase subunit is necessary and sufficient to direct association of Bdf1 and Swc7, as well as Arp4, Act1, Yaf9 and Swc4. This same region contains an additional H2AZ-H2B specific binding site, distinct from the previously identified Swc2 subunit. These findings suggest that one SWR1 enzyme might be capable of binding two H2AZ-H2B dimers, and provide further insight on the hierarchy and interdependency of molecular interactions within the SWR1 complex.

Interaction between serotonin transporter and serotonin receptor 1 B genes polymorphisms may be associated with antisocial alcoholism.

PubMed

Wang, Tzu-Yun; Lee, Sheng-Yu; Chen, Shiou-Lan; Chang, Yun-Hsuan; Chen, Shih-Heng; Chu, Chun-Hsien; Huang, San-Yuan; Tzeng, Nian-Sheng; Wang, Chen-Lin; Lee, I Hui; Yeh, Tzung Lieh; Yang, Yen Kuang; Lu, Ru-Band

2012-07-11

Several studies have hypothesized that genes regulating the components of the serotonin system, including serotonin transporter (5-HTTLPR) and serotonin 1 B receptor (5-HT1B), may be associated with alcoholism, but their results are contradictory because of alcoholism's heterogeneity. Therefore, we examined whether the 5-HTTLPR gene and 5-HT1B gene G861C polymorphism are susceptibility factors for a specific subtype of alcoholism, antisocial alcoholism in Han Chinese in Taiwan. We recruited 273 Han Chinese male inmates with antisocial personality disorder (ASPD) [antisocial alcoholism (AS-ALC) group (n=120) and antisocial non-alcoholism (AS-N-ALC) group (n=153)] and 191 healthy male controls from the community. Genotyping was done using PCR-RFLP. There were no significant differences in the genotypic frequency of the 5-HT1B G861C polymorphism between the 3 groups. Although AS-ALC group members more frequently carried the 5-HTTLPR S/S, S/LG, and LG/LG genotypes than controls, the difference became non-significant after controlling for the covarying effects of age. However, the 5-HTTLPR S/S, S/LG, and LG/LG genotypes may have interacted with the 5-HT1B G861C C/C polymorphism and increased the risk of becoming antisocial alcoholism. Our study suggests that neither the 5-HTTLPR gene nor the 5-HT1B G861C polymorphism alone is a risk factor for antisocial alcoholism in Taiwan's Han Chinese population, but that the interaction between both genes may increase susceptibility to antisocial alcoholism.

A gene duplication/loss event in the ribulose-1,5-bisphosphate-carboxylase/oxygenase (rubisco) small subunit gene family among accessions of Arabidopsis thaliana.

PubMed

Schwarte, Sandra; Tiedemann, Ralph

2011-06-01

Rubisco (ribulose-1,5-bisphosphate carboxylase/oxygenase; EC 4.1.1.39), the most abundant protein in nature, catalyzes the assimilation of CO(2) (worldwide about 10(11) t each year) by carboxylation of ribulose-1,5-bisphosphate. It is a hexadecamer consisting of eight large and eight small subunits. Although the Rubisco large subunit (rbcL) is encoded by a single gene on the multicopy chloroplast genome, the Rubisco small subunits (rbcS) are encoded by a family of nuclear genes. In Arabidopsis thaliana, the rbcS gene family comprises four members, that is, rbcS-1a, rbcS-1b, rbcS-2b, and rbcS-3b. We sequenced all Rubisco genes in 26 worldwide distributed A. thaliana accessions. In three of these accessions, we detected a gene duplication/loss event, where rbcS-1b was lost and substituted by a duplicate of rbcS-2b (called rbcS-2b*). By screening 74 additional accessions using a specific polymerase chain reaction assay, we detected five additional accessions with this duplication/loss event. In summary, we found the gene duplication/loss in 8 of 100 A. thaliana accessions, namely, Bch, Bu, Bur, Cvi, Fei, Lm, Sha, and Sorbo. We sequenced an about 1-kb promoter region for all Rubisco genes as well. This analysis revealed that the gene duplication/loss event was associated with promoter alterations (two insertions of 450 and 850 bp, one deletion of 730 bp) in rbcS-2b and a promoter deletion (2.3 kb) in rbcS-2b* in all eight affected accessions. The substitution of rbcS-1b by a duplicate of rbcS-2b (i.e., rbcS-2b*) might be caused by gene conversion. All four Rubisco genes evolve under purifying selection, as expected for central genes of the highly conserved photosystem of green plants. We inferred a single positive selected site, a tyrosine to aspartic acid substitution at position 72 in rbcS-1b. Exactly the same substitution compromises carboxylase activity in the cyanobacterium Anacystis nidulans. In A. thaliana, this substitution is associated with an inferred recombination. Functional implications of the substitution remain to be evaluated.

Genetic variability of Baylisascaris schroederi from the Qinling subspecies of the giant panda in China revealed by sequences of three mitochondrial genes.

PubMed

Zhao, Zhong-Hui; Bian, Qing-Qing; Ren, Wan-Xin; Cheng, Wen-Yu; Jia, Yan-Qing; Fang, Yan-Qin; Zhao, Guang-Hui

2014-06-01

The present study examined the variations in three mitochondrial (mt) DNA sequences, namely cytochrome b (cytb), cytochrome c oxidase subunit 3 (cox3) and NADH dehydrogenase subunit 5 (nad5), among Baylisascaris schroederi isolates from the Qinling subspecies of the giant panda in Shaanxi province, northwestern China. No differences in length were detected in the three mt fragments from different isolates. The intra-specific sequence variations within all B. schroederi samples were 0-2.6% for pcytb, 0-1.8% for pcox3 and 0-2.1% for pnad5, while the inter-specific sequence differences among members of the genus Baylisascaris were 8.2-15.2%, 6.2-15.9% and 8.4-16.0% for pcytb, pcox3, pnad5, respectively. A phylogenetic analysis of the combined sequences of pcytb, pcox3 and pnad 5 showed that all B. schroederi samples in the present study were located in two large clusters, with one cluster containing samples from giant pandas in Sichuan province. These findings provide basic information for further study of molecular epidemiology and control of B. schroederi infection in the Qinling subspecies of the giant panda and throughout China.

Intragenomic polymorphisms among high-copy loci: a genus-wide study of nuclear ribosomal DNA in Asclepias (Apocynaceae)

PubMed Central

Straub, Shannon C.K.; Fishbein, Mark; Liston, Aaron

2015-01-01

Despite knowledge that concerted evolution of high-copy loci is often imperfect, studies that investigate the extent of intragenomic polymorphisms and comparisons across a large number of species are rarely made. We present a bioinformatic pipeline for characterizing polymorphisms within an individual among copies of a high-copy locus. Results are presented for nuclear ribosomal DNA (nrDNA) across the milkweed genus, Asclepias. The 18S-26S portion of the nrDNA cistron of Asclepias syriaca served as a reference for assembly of the region from 124 samples representing 90 species of Asclepias. Reads were mapped back to each individual’s consensus and at each position reads differing from the consensus were tallied using a custom perl script. Low frequency polymorphisms existed in all individuals (mean = 5.8%). Most nrDNA positions (91%) were polymorphic in at least one individual, with polymorphic sites being less frequent in subunit regions and loops. Highly polymorphic sites existed in each individual, with highest abundance in the “noncoding” ITS regions. Phylogenetic signal was present in the distribution of intragenomic polymorphisms across the genus. Intragenomic polymorphisms in nrDNA are common in Asclepias, being found at higher frequency than any other study to date. The high and variable frequency of polymorphisms across species highlights concerns that phylogenetic applications of nrDNA may be error-prone. The new analytical approach provided here is applicable to other taxa and other high-copy regions characterized by low coverage genome sequencing (genome skimming). PMID:25653903

The Distribution of Genotype and Allelic Frequency of IL28B Gene Polymorphism in Andhra Pradesh, India

PubMed Central

Sivaprasad, Siddapuram; Rao, Padaki Nagaraja; Gupta, Rajesh; Ashwini, Kaitha; Reddy, Duvvuru Nageshwar

2012-01-01

Background The single nucleotide polymorphism (SNP) of IL28B gene on chromosome 19, encoding for the interferon (IFN)-λ-3 is strongly associated with treatment response to pegylated-IFN and ribavirin in patients infected with different genotypes of hepatitis C virus (HCV). Difference between ethnicity and treatment response rates suggesting a key role of host genetics. The IL28B polymorphism (rs12979860C/T) shows a marked differential distribution between racial groups. Aim The present study is aimed to evaluate genotype and allelic frequency of IL28B gene polymorphism (rs12979860C/T) in Andhra Pradesh, India. Methods A total of 220 healthy controls were recruited for the study. The genotyping of SNP rs12979860C/T on IL28B gene was performed by polymerase chain reaction-direct sequencing method. Result The frequency of CC genotype was found to be significantly (59.09%) higher compared to CT (34.09%) and TT (6.81%) genotypes, respectively. The frequency of major allele C is 0.762 whereas minor allele T is 0.238. Conclusion The higher distribution of genotype ‘CC’ of SNP, rs12979860C/T of IL28B gene in study subjects is suggestive of better response of HCV patients to standard anti-HCV therapy. PMID:25755419

[Clustered regularly interspaced short palindromic repeats (CRISPR) site in Bacillus anthracis].

PubMed

Gao, Zhiqi; Wang, Dongshu; Feng, Erling; Wang, Bingxiang; Hui, Yiming; Han, Shaobo; Jiao, Lei; Liu, Xiankai; Wang, Hengliang

2014-11-04

To investigate the polymorphism of clustered regularly interspaced short palindromic repeats (CRISPR) in Bacillu santhracis and the application to molecular typing based on the polymorphism of CRISPR in B. anthracis. We downloaded the whole genome sequence of 6 B. anthracis strains and extracted the CRISPR sites. We designed the primers of CRISPR sites and amplified the CRISPR fragments in 193 B. anthracis strains by PCR and sequenced these fragments. In order to reveal the polymorphism of CRISPR in B. anthracis, wealigned all the extracted sequences and sequenced results by local blasting. At the same time, we also analyzed the CRISPR sites in B. cereus and B. thuringiensis. We did not find any polymorphism of CRISPR in B. anthracis. The molecular typing approach based on CRISPR polymorphism is not suitable for B. anthracis, but it is possible for us to distinguish B. anthracis from B. cereus and B. thuringiensis.

Mapping of the immunophilin-immunosuppressant site of interaction on calcineurin.

PubMed

Husi, H; Luyten, M A; Zurini, M G

1994-05-13

The interaction of the immunosuppressive complexes cyclosporin A-cyclophilin A and FK506 binding protein-FK506 with the Ca(2+)- and calmodulin-dependent protein phosphatase calcineurin has been investigated by means of photoaffinity labeling and chemical cross-linking. Photolabeling of purified bovine brain calcineurin with the affinity label [O-[4-[4-(1-diazo-2,2,2-trifluoroethyl)benzoyl]aminobutanoyl]-D- serine8]cyclosporin in the presence of cyclophilin A results, in addition to the labeling of cyclophilin itself, in the transfer of some of the chemical probe to both the catalytic subunit A and the regulatory subunit B of calcineurin. Chemical cross-linking studies with disuccinimidyl suberate in the presence of either cyclophilin A, B, or C in complex with cyclosporin A or FK506 binding protein-FK506 result on the other hand in the apparently exclusive and strictly immunosuppressant-dependent formation of covalent immunophilin-calcineurin B subunit products. Cross-linking of immunophilins to calcineurin B subunit requires the presence of subunit A. In the present study, using a set of recombinant maltose-binding protein fusion products representing different stretches of the catalytic subunit A, we were able to map the minimal calcineurin A sequence necessary for immunophilin-ligand-calcineurin B interaction to occur.

Amerindian genetic ancestry and INDEL polymorphisms associated with susceptibility of childhood B-cell Leukemia in an admixed population from the Brazilian Amazon.

PubMed

Carvalho, Darlen C; Wanderley, Alayde V; Amador, Marcos A T; Fernandes, Marianne R; Cavalcante, Giovanna C; Pantoja, Karla B C C; Mello, Fernando A R; de Assumpção, Paulo P; Khayat, André S; Ribeiro-Dos-Santos, Ândrea; Santos, Sidney; Dos Santos, Ney P C

2015-08-20

Acute lymphoblastic leukemia (ALL) is a malignant tumor common in children. Studies of genetic susceptibility to cancer using biallelic insertion/deletion (INDEL) type polymorphisms associated with cancer development pathways may help to clarify etymology of ALL. In this study, we investigate the role of eight functional INDEL polymorphisms and influence of genetic ancestry to B-cell ALL susceptibility in children of Brazilian Amazon population, which has a high degree of inter-ethnic admixture. Ancestry analysis was estimated using a panel of 48 autosomal ancestry informative markers. 130 B-cell ALL patients and 125 healthy controls were included in this study. The odds ratios and 95% confidence intervals were adjusted for confounders. The results indicated an association between the investigated INDEL polymorphisms in CASP8 (rs3834129), CYP19A1 (rs11575899) e XRCC1 (rs3213239) genes in the development of B-cell ALL. The carriers of Insertion/Insertion (Ins/Ins) genotype of the polymorphism in CASP8 gene presented reduced chances of developing B-cell ALL (P=0.001; OR=0.353; 95% CI=0.192-0.651). The Deletion/Deletion (Del/Del) genotype of the polymorphism in CYP19A1 gene was associated to a lower chance of developing B-cell ALL (P=3.35×10 -6 ; OR=0.121; 95% CI=0.050-0.295), while Del/Del genotype of the polymorphism in XRCC1 gene was associated to a higher chance of developing B-cell ALL (P=2.01×10 -4 ; OR=6.559; 95% CI=2.433-17.681). We also found that Amerindian ancestry correlates with the risk of B-cell ALL. For each increase of 10% in the Amerindian ancestry results in 1.4-fold chances of developing B-cell ALL (OR=1.406; 95% IC=1.123-1.761), while each increase of 10% in the European ancestry presents a protection effect in the development of B-cell ALL (OR=0.666; 95% IC=0.536-0.827). The results suggest that genetic factors influence leukemogenesis and might be explored in the stratification of B-cell ALL risk in admixed populations. Copyright © 2015 Z. Published by Elsevier Ltd.. All rights reserved.

Naturally occurring mutations associated with resistance to HCV NS5B polymerase and NS3 protease inhibitors in treatment-naïve patients with chronic hepatitis C.

PubMed

Costantino, Angela; Spada, Enea; Equestre, Michele; Bruni, Roberto; Tritarelli, Elena; Coppola, Nicola; Sagnelli, Caterina; Sagnelli, Evangelista; Ciccaglione, Anna Rita

2015-11-14

The detection of baseline resistance mutations to new direct-acting antivirals (DAAs) in HCV chronically infected treatment-naïve patients could be important for their management and outcome prevision. In this study, we investigated the presence of mutations, which have been previously reported to be associated with resistance to DAAs in HCV polymerase (NS5B) and HCV protease (NS3) regions, in sera of treatment-naïve patients. HCV RNA from 152 naïve patients (84 % Italian and 16 % immigrants from various countries) infected with different HCV genotypes (21,1a; 21, 1b; 2, 2a; 60, 2c; 22, 3a; 25, 4d and 1, 4k) was evaluated for sequence analysis. Amplification and sequencing of fragments in the NS5B (nt 8256-8640) and NS3 (nt 3420-3960) regions of HCV genome were carried out for 152 and 28 patients, respectively. The polymorphism C316N/H in NS5B region, associated with resistance to sofosbuvir, was detected in 9 of the 21 (43 %) analysed sequences from genotype 1b-infected patients. Naturally occurring mutations V36L, and M175L in the NS3 protease region were observed in 100 % of patients infected with subtype 2c and 4. A relevant proportion of treatment naïve genotype 1b infected patients evaluated in this study harboured N316 polymorphism and might poorly respond to sofosbuvir treatment. As sofosbuvir has been approved for treatment of HCV chronic infection in USA and Europe including Italy, pre-treatment testing for N316 polymorphism on genotype 1b naïve patients should be considered for this drug.

TrkB activation by 7, 8-dihydroxyflavone increases synapse AMPA subunits and ameliorates spatial memory deficits in a mouse model of Alzheimer's disease.

PubMed

Gao, Lei; Tian, Mi; Zhao, Hong-Yun; Xu, Qian-Qian; Huang, Yu-Ming; Si, Qun-Cao; Tian, Qing; Wu, Qing-Ming; Hu, Xia-Min; Sun, Li-Bo; McClintock, Shawn M; Zeng, Yan

2016-02-01

We recently demonstrated that activation of tyrosine receptor kinase B (TrkB) by 7, 8-dihydroxyflavone (7, 8-DHF), the selective TrkB agonist, increased surface alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA) receptors (AMPARs) AMPA receptor subunit GluR1 (GluA1) subunit expression at the synapses of Fragile X Syndrome mutant mice. This present study investigated the effects of 7, 8-DHF on both memory function and synapse structure in relation to the synapse protein level of AMPARs in the Tg2576 Alzheimer's disease (AD) mouse model. The study found that chronic oral administration of 7, 8-DHF significantly improved spatial memory and minimized dendrite loss in the hippocampus of Tg2576 mice. A key feature of 7, 8-DHF action was the increased expression of both GluA1 and GluA2 at synapses. Interestingly, 7, 8-DHF had no effect on the attenuation of amyloid precursor protein or Aβ exhibiting in the Tg2576 AD brains, yet it activated the phosphorylation of TrkB receptors and its downstream signals including CaMKII, Akt, Erk1/2, and cAMP-response element-binding protein. Importantly, cyclotraxin B (a TrkB inhibitor), U0126 (a Ras-ERK pathway inhibitor), Wortmannin (an Akt phosphorylation inhibitor), and KN-93 (a CaMKII inhibitor) counteracted the enhanced expression and phosphorylation of AMPAR subunits induced by 7, 8-DHF. Collectively, our results demonstrated that 7, 8-DHF acted on TrkB and resolved learning and memory impairments in the absence of reduced amyloid in amyloid precursor protein transgenic mice partially through improved synaptic structure and enhanced synaptic AMPARs. The findings suggest that the application of 7, 8-DHF may be a promising new approach to improve cognitive abilities in AD. We provided extensive data demonstrating that 7, 8-dihydroflavone, the TrkB agonist, improved Tg2576 mice spatial memory. This improvement is correlated with a reversion to normal values of GluA1 and GluA2 AMPA receptor subunits and dendritic spines in CA1. This work suggests that 7, 8-DHF is a suitable drug to potentiate in vivo Tropomyosin receptor kinase B (TrkB) signaling in the Alzheimer's disease mice model. © 2015 International Society for Neurochemistry.

Indinavir and nelfinavir inhibit proximal insulin receptor signaling and salicylate abrogates inhibition: potential role of the NFkappa B pathway.

PubMed

Ismail, Wan Iryani W; King, Judy A; Anwar, Khawar; Pillay, Tahir S

2013-08-01

The molecular basis of insulin resistance induced by HIV protease inhibitors (HPIs) remains unclear. In this study, Chinese hamster ovary cells transfected with high levels of human insulin receptor (CHO-IR) and 3T3-L1 adipocytes were used to elucidate the mechanism of this side effect. Indinavir and nelfinavir induced a significant decrease in tyrosine phosphorylation of the insulin receptor β-subunit. Indinavir caused a significant increase in the phosphorylation of insulin receptor substrate-1 (IRS-1) on serine 307 (S307) in both CHO-IR cells and 3T3-L1 adipocytes. Nelfinavir also inhibited phosphorylation of Map/ERK kinase without affecting insulin-stimulated Akt phosphorylation. Concomitantly, levels of protein tyrosine phosphatase 1B (PTP1B), suppressor of cytokines signaling-1 and -3 (SOCS-1 and -3), Src homology 2B (SH2B) and adapter protein with a pleckstrin homology domain and an SH2 domain (APS) were not altered significantly. When CHO-IR cells were pre-treated with sodium salicylate (NaSal), the effects of indinavir on tyrosine phosphorylation of the IR β-subunit and phosphorylation of IRS-1 at S307 were abrogated. These data suggest a potential role for the NFκB pathway in insulin resistance induced by HPIs. Copyright © 2013 Wiley Periodicals, Inc.

Regulation of Na(+)/K(+)-ATPase by nuclear respiratory factor 1: implication in the tight coupling of neuronal activity, energy generation, and energy consumption.

PubMed

Johar, Kaid; Priya, Anusha; Wong-Riley, Margaret T T

2012-11-23

NRF-1 regulates mediators of neuronal activity and energy generation. NRF-1 transcriptionally regulates Na(+)/K(+)-ATPase subunits α1 and β1. NRF-1 functionally regulates mediators of energy consumption in neurons. NRF-1 mediates the tight coupling of neuronal activity, energy generation, and energy consumption at the molecular level. Energy generation and energy consumption are tightly coupled to neuronal activity at the cellular level. Na(+)/K(+)-ATPase, a major energy-consuming enzyme, is well expressed in neurons rich in cytochrome c oxidase, an important enzyme of the energy-generating machinery, and glutamatergic receptors that are mediators of neuronal activity. The present study sought to test our hypothesis that the coupling extends to the molecular level, whereby Na(+)/K(+)-ATPase subunits are regulated by the same transcription factor, nuclear respiratory factor 1 (NRF-1), found recently by our laboratory to regulate all cytochrome c oxidase subunit genes and some NMDA and AMPA receptor subunit genes. By means of multiple approaches, including in silico analysis, electrophoretic mobility shift and supershift assays, in vivo chromatin immunoprecipitation, promoter mutational analysis, and real-time quantitative PCR, NRF-1 was found to functionally bind to the promoters of Atp1a1 and Atp1b1 genes but not of the Atp1a3 gene in neurons. The transcripts of Atp1a1 and Atp1b1 subunit genes were up-regulated by KCl and down-regulated by tetrodotoxin. Atp1b1 is positively regulated by NRF-1, and silencing of NRF-1 with small interference RNA blocked the up-regulation of Atp1b1 induced by KCl, whereas overexpression of NRF-1 rescued these transcripts from being suppressed by tetrodotoxin. On the other hand, Atp1a1 is negatively regulated by NRF-1. The binding sites of NRF-1 on Atp1a1 and Atp1b1 are conserved among mice, rats, and humans. Thus, NRF-1 regulates key Na(+)/K(+)-ATPase subunits and plays an important role in mediating the tight coupling between energy consumption, energy generation, and neuronal activity at the molecular level.

Structure-Function, Stability, and Chemical Modification of the Cyanobacterial Cytochrome b[subscript 6]f Complex from Nostoc sp. PCC 7120

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baniulis, Danas; Yamashita, Eiki; Whitelegge, Julian P.

2009-06-08

The crystal structure of the cyanobacterial cytochrome b{sub 6}f complex has previously been solved to 3.0-{angstrom} resolution using the thermophilic Mastigocladus laminosus whose genome has not been sequenced. Several unicellular cyanobacteria, whose genomes have been sequenced and are tractable for mutagenesis, do not yield b{sub 6}f complex in an intact dimeric state with significant electron transport activity. The genome of Nostoc sp. PCC 7120 has been sequenced and is closer phylogenetically to M. laminosus than are unicellular cyanobacteria. The amino acid sequences of the large core subunits and four small peripheral subunits of Nostoc are 88 and 80% identical tomore » those in the M. laminosus b{sub 6}f complex. Purified b{sub 6}f complex from Nostoc has a stable dimeric structure, eight subunits with masses similar to those of M. laminosus, and comparable electron transport activity. The crystal structure of the native b{sub 6}f complex, determined to a resolution of 3.0{angstrom} (PDB id: 2ZT9), is almost identical to that of M. laminosus. Two unique aspects of the Nostoc complex are: (i) a dominant conformation of heme b{sub p} that is rotated 180 deg. about the {alpha}- and {gamma}-meso carbon axis relative to the orientation in the M. laminosus complex and (ii) acetylation of the Rieske iron-sulfur protein (PetC) at the N terminus, a post-translational modification unprecedented in cyanobacterial membrane and electron transport proteins, and in polypeptides of cytochrome bc complexes from any source. The high spin electronic character of the unique heme cn is similar to that previously found in the b{sub 6}f complex from other sources.« less

Cigarettes, genetic background, and menopausal timing: the presence of single nucleotide polymorphisms in cytochrome P450 genes is associated with increased risk of natural menopause in European-American smokers.

PubMed

Butts, Samantha F; Sammel, Mary D; Greer, Christine; Rebbeck, Timothy R; Boorman, David W; Freeman, Ellen W

2014-07-01

This study aims to evaluate associations between variations in genes involved in the metabolism of environmental chemicals and steroid hormones and risk of menopause in smokers. Survival analysis was performed on 410 eligible participants from the Penn Ovarian Aging study (ongoing for 14 years), a cohort study of late-reproductive-age women. Single nucleotide polymorphisms at the following loci were studied: COMT Val158Met, CYP1B1*4 Asn452Ser, CYP1B1*3 Leu432Val, and CYP3A4*1B. Significant interactions between smoking and single nucleotide polymorphisms were observed in European-American carriers of CYP3A4*1B and CYP1B1*3, supporting a greater risk of menopause entry compared with those not carrying these alleles. Among CYP1B1*3 carriers, smokers had a greater risk of menopause entry than nonsmokers (adjusted hazard ratio [HR], 2.26; 95% CI, 1.4-3.67; median time to menopause, 10.42 and 11.07 y, respectively). No association between smoking and menopause was identified in CYP1B1 wild types. Among CYP3A4*1B carriers, smokers were at greater risk for menopause entry than nonsmokers (adjusted HR, 15.1; 95% CI, 3.31-69.2; median time to menopause, 11.36 and 13.91 y, respectively). Risk of menopause entry in CYP3A4 wild types who smoked was far lower (adjusted HR, 1.59; 95% CI, 1.03-2.44). Heavily smoking CYP1B1*3 carriers (adjusted HR, 3.0; 95% CI, 1.54-5.84; median time to menopause, 10.41 y) and heavily smoking CYP3A4*1B carriers (adjusted HR, 17.79; 95% CI, 3.21-98.65; median time to menopause, 5.09 y) had the greatest risk of menopause entry. Our finding that the risk of menopause entry in European-American smokers varies depending on genetic background represents a novel gene-environment interaction in reproductive aging.

Cigarettes, genetic background, and menopausal timing: the presence of single nucleotide polymorphisms in cytochrome P450 genes is associated with increased risk of natural menopause in European-American smokers

PubMed Central

Butts, Samantha F.; Sammel, Mary D.; Greer, Christine; Rebbeck, Timothy R.; Boorman, David W.; Freeman, Ellen W.

2016-01-01

Objective This study aims to evaluate associations between variations in genes involved in the metabolism of environmental chemicals and steroid hormones and risk of menopause in smokers. Methods Survival analysis was performed on 410 eligible participants from the Penn Ovarian Aging study (ongoing for 14 years), a cohort study of late-reproductive-age women. Single nucleotide polymorphisms at the following loci were studied: COMT Val158Met, CYP1B1*4 Asn452Ser, CYP1B1*3 Leu432Val, and CYP3A4*1B. Results Significant interactions between smoking and single nucleotide polymorphisms were observed in European-American carriers of CYP3A4*1B and CYP1B1*3, supporting a greater risk of menopause entry compared with those not carrying these alleles. Among CYP1B1*3 carriers, smokers had a greater risk of menopause entry than nonsmokers (adjusted hazard ratio [HR], 2.26; 95% CI, 1.4–3.67; median time to menopause, 10.42 and 11.07 y, respectively). No association between smoking and menopause was identified in CYP1B1 wild types. Among CYP3A4*1B carriers, smokers were at greater risk for menopause entry than nonsmokers (adjusted HR, 15.1; 95% CI, 3.31–69.2; median time to menopause, 11.36 and 13.91 y, respectively). Risk of menopause entry in CYP3A4 wild types who smoked was far lower (adjusted HR, 1.59; 95% CI, 1.03–2.44). Heavily smoking CYP1B1*3 carriers (adjusted HR, 3.0; 95% CI, 1.54–5.84; median time to menopause, 10.41 y) and heavily smoking CYP3A4*1B carriers (adjusted HR, 17.79; 95% CI, 3.21–98.65; median time to menopause, 5.09 y) had the greatest risk of menopause entry. Conclusions Our finding that the risk of menopause entry in European-American smokers varies depending on genetic background represents a novel gene-environment interaction in reproductive aging. PMID:24448104

Linked PNPLA3 polymorphisms confer susceptibility to nonalcoholic steatohepatitis and decreased viral load in chronic hepatitis B.

PubMed

Pan, Qin; Zhang, Rui-Nan; Wang, Yu-Qin; Zheng, Rui-Dan; Mi, Yu-Qiang; Liu, Wen-Bin; Shen, Feng; Chen, Guang-Yu; Lu, Jia-Fa; Zhu, Chan-Yan; Zhang, Shu-Yi; Chen, Yi-Ming; Sun, Wan-Lu; Fan, Jian-Gao

2015-07-28

To investigate the association of PNPLA3 polymorphisms with concurrent chronic hepatitis B (CHB) and nonalcoholic fatty liver disease (NAFLD). A cohort of Han patients with biopsy-proven CHB, with or without NAFLD (CHB group, n = 51; CHB + NAFLD group, n = 57), and normal controls (normal group, n = 47) were recruited from Northern (Tianjin), Central (Shanghai), and Southern (Zhangzhou) China. Their PNPLA3 polymorphisms were genotyped by gene sequencing. The association between PNPLA3 polymorphisms and susceptibility to NAFLD, and clinical characteristics of NAFLD were evaluated on the basis of physical indices, liver function tests, glycolipid metabolism, and histopathologic scoring. The association of PNPLA3 polymorphisms and hepatitis B virus (HBV) load was determined by the serum level of HBV DNA. After adjusting for age, sex, and body mass index, we found that four linked single nucleotide polymorphisms (SNPs) of PNPLA3, including the rs738409 G allele (CHB + NAFLD group vs CHB group: odds ratio [OR] = 2.77, 95% confidence interval [CI]: 1.18-6.54; P = 0.02), rs3747206 T allele (CHB + NAFLD group vs CHB group: OR = 2.77, 95%CI: 1.18-6.54; P = 0.02), rs4823173 A allele (CHB + NAFLD group vs CHB group: OR = 2.73, 95%CI: 1.16-6.44; P = 0.02), and rs2072906 G allele (CHB + NAFLD group vs CHB group: OR = 3.05, 95%CI: 1.28-7.26; P = 0.01), conferred high risk to NAFLD in CHB patients. In patients with both CHB and NAFLD, these genotypes of PNPLA3 polymorphisms were associated with increased susceptibility to nonalcoholic steatohepatitis (NASH) (NAFLD activity score ≥ 3; P = 0.01-0.03) and liver fibrosis (> 1 Metavir grading; P = 0.01-0.04). As compared to those with C/C and C/G at rs738409, C/C and C/T at rs3747206, G/G and G/A at rs4823173, and A/A and A/G at rs2072906, patients in the CHB + NAFLD group with G/G at rs738409, T/T at rs3747206, A/A at rs4823173, and G/G at rs2072906 showed significantly lower serum levels of HBV DNA (P < 0.01-0.05). Four linked SNPs of PNPLA3 (rs738409, rs3747206, rs4823173, and rs2072906) are correlated with susceptibility to NAFLD, NASH, liver fibrosis, and HBV dynamics in CHB patients.

Linked PNPLA3 polymorphisms confer susceptibility to nonalcoholic steatohepatitis and decreased viral load in chronic hepatitis B

PubMed Central

Pan, Qin; Zhang, Rui-Nan; Wang, Yu-Qin; Zheng, Rui-Dan; Mi, Yu-Qiang; Liu, Wen-Bin; Shen, Feng; Chen, Guang-Yu; Lu, Jia-Fa; Zhu, Chan-Yan; Zhang, Shu-Yi; Chen, Yi-Ming; Sun, Wan-Lu; Fan, Jian-Gao

2015-01-01

AIM: To investigate the association of PNPLA3 polymorphisms with concurrent chronic hepatitis B (CHB) and nonalcoholic fatty liver disease (NAFLD). METHODS: A cohort of Han patients with biopsy-proven CHB, with or without NAFLD (CHB group, n = 51; CHB + NAFLD group, n = 57), and normal controls (normal group, n = 47) were recruited from Northern (Tianjin), Central (Shanghai), and Southern (Zhangzhou) China. Their PNPLA3 polymorphisms were genotyped by gene sequencing. The association between PNPLA3 polymorphisms and susceptibility to NAFLD, and clinical characteristics of NAFLD were evaluated on the basis of physical indices, liver function tests, glycolipid metabolism, and histopathologic scoring. The association of PNPLA3 polymorphisms and hepatitis B virus (HBV) load was determined by the serum level of HBV DNA. RESULTS: After adjusting for age, sex, and body mass index, we found that four linked single nucleotide polymorphisms (SNPs) of PNPLA3, including the rs738409 G allele (CHB + NAFLD group vs CHB group: odds ratio [OR] = 2.77, 95% confidence interval [CI]: 1.18-6.54; P = 0.02), rs3747206 T allele (CHB + NAFLD group vs CHB group: OR = 2.77, 95%CI: 1.18-6.54; P = 0.02), rs4823173 A allele (CHB + NAFLD group vs CHB group: OR = 2.73, 95%CI: 1.16-6.44; P = 0.02), and rs2072906 G allele (CHB + NAFLD group vs CHB group: OR = 3.05, 95%CI: 1.28-7.26; P = 0.01), conferred high risk to NAFLD in CHB patients. In patients with both CHB and NAFLD, these genotypes of PNPLA3 polymorphisms were associated with increased susceptibility to nonalcoholic steatohepatitis (NASH) (NAFLD activity score ≥ 3; P = 0.01-0.03) and liver fibrosis (> 1 Metavir grading; P = 0.01-0.04). As compared to those with C/C and C/G at rs738409, C/C and C/T at rs3747206, G/G and G/A at rs4823173, and A/A and A/G at rs2072906, patients in the CHB + NAFLD group with G/G at rs738409, T/T at rs3747206, A/A at rs4823173, and G/G at rs2072906 showed significantly lower serum levels of HBV DNA (P < 0.01-0.05). CONCLUSION: Four linked SNPs of PNPLA3 (rs738409, rs3747206, rs4823173, and rs2072906) are correlated with susceptibility to NAFLD, NASH, liver fibrosis, and HBV dynamics in CHB patients. PMID:26229402

Missense Gamma-Aminobutyric Acid Receptor Polymorphisms Are Associated with Reaction Time, Motor Time, and Ethanol Effects in Vivo.

PubMed

García-Martín, Elena; Ramos, María I; Cornejo-García, José A; Galván, Segismundo; Perkins, James R; Rodríguez-Santos, Laura; Alonso-Navarro, Hortensia; Jiménez-Jiménez, Félix J; Agúndez, José A G

2018-01-01

Background: The Gamma-aminobutyric acid type A receptor (GABA-A receptor) is affected by ethanol concentrations equivalent to those reached during social drinking. At these concentrations, ethanol usually causes impairment in reaction and motor times in most, but not all, individuals. Objectives: To study the effect of GABA-A receptor variability in motor and reaction times, and the effect of low ethanol doses. Methods: Two hundred and fifty healthy subjects received one single dose of 0.5 g/Kg ethanol per os . Reaction and motor times were determined before ethanol challenge (basal), and when participants reached peak ethanol concentrations. We analyzed all common missense polymorphisms described in the 19 genes coding for the GABA-A receptor subunits by using TaqMan probes. Results: The GABRA6 rs4454083 T/C polymorphisms were related to motor times, with individuals carrying the C/C genotype having faster motor times, both, at basal and at peak ethanol concentrations. The GABRA4 rs2229940 T/T genotype was associated to faster reaction times and with lower ethanol effects, determined as the difference between basal reaction time and reaction time at peak concentrations. All these associations remained significant after correction for multiple comparisons. No significant associations were observed for the common missense SNPs GABRB3 rs12910925, GABRG2 rs211035, GABRE rs1139916, GABRP rs1063310, GABRQ rs3810651, GABRR1 rs12200969 or rs1186902, GABRR2 rs282129, and GABRR3 rs832032. Conclusions: This study provides novel information supporting a role of missense GABA-A receptor polymorphisms in reaction time, motor time and effects of low ethanol doses in vivo .

GM2 gangliosidosis associated with a HEXA missense mutation in Japanese Chin dogs: a potential model for Tay Sachs disease.

PubMed

Sanders, Douglas N; Zeng, Rong; Wenger, David A; Johnson, Gary S; Johnson, Gayle C; Decker, Jared E; Katz, Martin L; Platt, Simon R; O'Brien, Dennis P

2013-01-01

GM2 gangliosidosis is a fatal lysosomal storage disease caused by a deficiency of β-hexosaminidase (EC 3.2.1.52). There are two major isoforms of the enzyme: hexosaminidase A composed of an α and a β subunit (encoded by HEXA and HEXB genes, respectively); and, hexosaminidase B composed of two β subunits. Hexosaminidase A requires an activator protein encoded by GM2A to catabolize GM2 ganglioside, but even in the absence of the activator protein, it can hydrolyze the synthetic substrates commonly used to assess enzyme activity. GM2 gangliosidosis has been reported in Japanese Chin dogs, and we identified the disease in two related Japanese Chin dogs based on clinical signs, histopathology and elevated brain GM2 gangliosides. As in previous reports, we found normal or elevated hexosaminidase activity when measured with the synthetic substrates. This suggested that the canine disease is analogous to human AB variant of G(M2) gangliosidosis, which results from mutations in GM2A. However, only common neutral single nucleotide polymorphisms were found upon sequence analysis of the canine ortholog of GM2A from the affected Japanese Chins. When the same DNA samples were used to sequence HEXA, we identified a homozygous HEXA:c967G>A transition which predicts a p.E323K substitution. The glutamyl moiety at 323 is known to make an essential contribution to the active site of hexosaminidase A, and none of the 128 normal Japanese Chins and 92 normal dogs of other breeds that we tested was homozygous for HEXA:c967A. Thus it appears that the HEXA:c967G>A transition is responsible for the GM2 gangliosidosis in Japanese Chins. Copyright © 2012 Elsevier Inc. All rights reserved.

ULK3 regulates cytokinetic abscission by phosphorylating ESCRT-III proteins

DOE PAGES

Caballe, Anna; Wenzel, Dawn M.; Agromayor, Monica; ...

2015-05-26

The endosomal sorting complexes required for transport (ESCRT) machinery mediates the physical separation between daughter cells during cytokinetic abscission. This process is regulated by the abscission checkpoint, a genome protection mechanism that relies on Aurora B and the ESCRT-III subunit CHMP4C to delay abscission in response to chromosome missegregation. In this study, we show that Unc-51-like kinase 3 (ULK3) phosphorylates and binds ESCRT-III subunits via tandem MIT domains, and thereby, delays abscission in response to lagging chromosomes, nuclear pore defects, and tension forces at the midbody. Our structural and biochemical studies reveal an unusually tight interaction between ULK3 and IST1,more » an ESCRT-III subunit required for abscission. We also demonstrate that IST1 phosphorylation by ULK3 is an essential signal required to sustain the abscission checkpoint and that ULK3 and CHMP4C are functionally linked components of the timer that controls abscission in multiple physiological situations.« less

ULK3 regulates cytokinetic abscission by phosphorylating ESCRT-III proteins

DOE Office of Scientific and Technical Information (OSTI.GOV)

Caballe, Anna; Wenzel, Dawn M.; Agromayor, Monica

The endosomal sorting complexes required for transport (ESCRT) machinery mediates the physical separation between daughter cells during cytokinetic abscission. This process is regulated by the abscission checkpoint, a genome protection mechanism that relies on Aurora B and the ESCRT-III subunit CHMP4C to delay abscission in response to chromosome missegregation. In this study, we show that Unc-51-like kinase 3 (ULK3) phosphorylates and binds ESCRT-III subunits via tandem MIT domains, and thereby, delays abscission in response to lagging chromosomes, nuclear pore defects, and tension forces at the midbody. Our structural and biochemical studies reveal an unusually tight interaction between ULK3 and IST1,more » an ESCRT-III subunit required for abscission. We also demonstrate that IST1 phosphorylation by ULK3 is an essential signal required to sustain the abscission checkpoint and that ULK3 and CHMP4C are functionally linked components of the timer that controls abscission in multiple physiological situations.« less

ULK3 regulates cytokinetic abscission by phosphorylating ESCRT-III proteins

PubMed Central

Caballe, Anna; Wenzel, Dawn M; Agromayor, Monica; Alam, Steven L; Skalicky, Jack J; Kloc, Magdalena; Carlton, Jeremy G; Labrador, Leticia; Sundquist, Wesley I; Martin-Serrano, Juan

2015-01-01

The endosomal sorting complexes required for transport (ESCRT) machinery mediates the physical separation between daughter cells during cytokinetic abscission. This process is regulated by the abscission checkpoint, a genome protection mechanism that relies on Aurora B and the ESCRT-III subunit CHMP4C to delay abscission in response to chromosome missegregation. In this study, we show that Unc-51-like kinase 3 (ULK3) phosphorylates and binds ESCRT-III subunits via tandem MIT domains, and thereby, delays abscission in response to lagging chromosomes, nuclear pore defects, and tension forces at the midbody. Our structural and biochemical studies reveal an unusually tight interaction between ULK3 and IST1, an ESCRT-III subunit required for abscission. We also demonstrate that IST1 phosphorylation by ULK3 is an essential signal required to sustain the abscission checkpoint and that ULK3 and CHMP4C are functionally linked components of the timer that controls abscission in multiple physiological situations. DOI: http://dx.doi.org/10.7554/eLife.06547.001 PMID:26011858

Meta-analysis of genome-wide association studies identifies common susceptibility polymorphisms for colorectal and endometrial cancer near SH2B3 and TSHZ1

PubMed Central

Cheng, Timothy HT; Thompson, Deborah; Painter, Jodie; O’Mara, Tracy; Gorman, Maggie; Martin, Lynn; Palles, Claire; Jones, Angela; Buchanan, Daniel D.; Ko Win, Aung; Hopper, John; Jenkins, Mark; Lindor, Noralane M.; Newcomb, Polly A.; Gallinger, Steve; Conti, David; Schumacher, Fred; Casey, Graham; Giles, Graham G; Pharoah, Paul; Peto, Julian; Cox, Angela; Swerdlow, Anthony; Couch, Fergus; Cunningham, Julie M; Goode, Ellen L; Winham, Stacey J; Lambrechts, Diether; Fasching, Peter; Burwinkel, Barbara; Brenner, Hermann; Brauch, Hiltrud; Chang-Claude, Jenny; Salvesen, Helga B.; Kristensen, Vessela; Darabi, Hatef; Li, Jingmei; Liu, Tao; Lindblom, Annika; Hall, Per; de Polanco, Magdalena Echeverry; Sans, Monica; Carracedo, Angel; Castellvi-Bel, Sergi; Rojas-Martinez, Augusto; Aguiar Jnr, Samuel; Teixeira, Manuel R.; Dunning, Alison M; Dennis, Joe; Otton, Geoffrey; Proietto, Tony; Holliday, Elizabeth; Attia, John; Ashton, Katie; Scott, Rodney J; McEvoy, Mark; Dowdy, Sean C; Fridley, Brooke L; Werner, Henrica MJ; Trovik, Jone; Njolstad, Tormund S; Tham, Emma; Mints, Miriam; Runnebaum, Ingo; Hillemanns, Peter; Dörk, Thilo; Amant, Frederic; Schrauwen, Stefanie; Hein, Alexander; Beckmann, Matthias W; Ekici, Arif; Czene, Kamila; Meindl, Alfons; Bolla, Manjeet K; Michailidou, Kyriaki; Tyrer, Jonathan P; Wang, Qin; Ahmed, Shahana; Healey, Catherine S; Shah, Mitul; Annibali, Daniela; Depreeuw, Jeroen; Al-Tassan, Nada A.; Harris, Rebecca; Meyer, Brian F.; Whiffin, Nicola; Hosking, Fay J; Kinnersley, Ben; Farrington, Susan M.; Timofeeva, Maria; Tenesa, Albert; Campbell, Harry; Haile, Robert W.; Hodgson, Shirley; Carvajal-Carmona, Luis; Cheadle, Jeremy P.; Easton, Douglas; Dunlop, Malcolm; Houlston, Richard; Spurdle, Amanda; Tomlinson, Ian

2015-01-01

High-risk mutations in several genes predispose to both colorectal cancer (CRC) and endometrial cancer (EC). We therefore hypothesised that some lower-risk genetic variants might also predispose to both CRC and EC. Using CRC and EC genome-wide association series, totalling 13,265 cancer cases and 40,245 controls, we found that the protective allele [G] at one previously-identified CRC polymorphism, rs2736100 near TERT, was associated with EC risk (odds ratio (OR) = 1.08, P = 0.000167); this polymorphism influences the risk of several other cancers. A further CRC polymorphism near TERC also showed evidence of association with EC (OR = 0.92; P = 0.03). Overall, however, there was no good evidence that the set of CRC polymorphisms was associated with EC risk, and neither of two previously-reported EC polymorphisms was associated with CRC risk. A combined analysis revealed one genome-wide significant polymorphism, rs3184504, on chromosome 12q24 (OR = 1.10, P = 7.23 × 10−9) with shared effects on CRC and EC risk. This polymorphism, a missense variant in the gene SH2B3, is also associated with haematological and autoimmune disorders, suggesting that it influences cancer risk through the immune response. Another polymorphism, rs12970291 near gene TSHZ1, was associated with both CRC and EC (OR = 1.26, P = 4.82 × 10−8), with the alleles showing opposite effects on the risks of the two cancers. PMID:26621817

Genetic characterisation of Taenia multiceps cysts from ruminants in Greece.

PubMed

Al-Riyami, Shumoos; Ioannidou, Evi; Koehler, Anson V; Hussain, Muhammad H; Al-Rawahi, Abdulmajeed H; Giadinis, Nektarios D; Lafi, Shawkat Q; Papadopoulos, Elias; Jabbar, Abdul

2016-03-01

This study was designed to genetically characterise the larval stage (coenurus) of Taenia multiceps from ruminants in Greece, utilising DNA regions within the cytochrome c oxidase subunit 1 (partial cox1) and NADH dehydrogenase 1 (pnad1) mitochondrial (mt) genes, respectively. A molecular-phylogenetic approach was used to analyse the pcox1 and pnad1 amplicons derived from genomic DNA samples from individual cysts (n=105) from cattle (n=3), goats (n=5) and sheep (n=97). Results revealed five and six distinct electrophoretic profiles for pcox1 and pnad1, respectively, using single-strand conformation polymorphism. Direct sequencing of selected amplicons representing each of these profiles defined five haplotypes each for pcox1 and pnad1, among all 105 isolates. Phylogenetic analysis of individual sequence data for each locus, including a range of well-defined reference sequences, inferred that all isolates of T. multiceps cysts from ruminants in Greece clustered with previously published sequences from different continents. The present study provides a foundation for future large-scale studies on the epidemiology of T. multiceps in ruminants as well as dogs in Greece. Copyright © 2015 Elsevier B.V. All rights reserved.

Characterization of photosystem 1 chlorophyll a/b-binding apoprotein accumulation in developing soybean using type-specific antibodies

NASA Technical Reports Server (NTRS)

Henry, R. L.; Armbrust, T.; Gallegos, G.; Guikema, J. A.; Spooner, B. S. (Principal Investigator)

1992-01-01

The structure and supramolecular assembly of the soybean photosystem 1 (PS 1) chlorophyll a/b-binding antenna (LHC 1) was examined. We identified the subunit composition of LHC 1 in soybean and followed the accumulation of individual subunits during light-induced assembly. We observed four LHC 1 subunits, at 23, 22, 21 and 20.5 kDa, obtained partial sequence information by amino-terminal sequence analysis, and classified the 20.5, 22, and 21 kDa subunits as being encoded by type I, II, and IV chlorophyll a/b binding protein genes, respectively. Antisera against LHC 1 subunits were used to follow the accumulation of individual subunits during the light-initiated transition from etioplast to chloroplast. Several points are noteworthy. First, monospecific antibody against the 22 kDa subunit decorated a 25 kDa peptide in etiolated tissue, which declined during maturation. This decline correlated with the light-induced appearance of mature 22 kDa peptide, suggesting a precursor/product relationship. Second, the same antibody identified a 22 kDa protein in mature corn, but not a larger band in etiolated corn, suggesting that LHC 1 accumulation is regulated differently between species before the onset of chlorophyll biosynthesis. Third, the mature 22 kDa subunit appeared somewhat later than the other LHC 1 peptides during greening, implying that this subunit is less intimately associated with the PS1 core than are the subunits appearing earlier in development.

No association between FCGR2A and FCGR3A polymorphisms in Guillain-Barré Syndrome in a Brazilian population.

PubMed

Dourado, Mario Emilio; Ferreira, Leonardo Capistrano; Freire-Neto, Francisco Paulo; Jeronimo, Selma M B

2016-09-15

The pathogenesis of Guillain-Barré Syndrome (GBS) is not entirely understood, but includes infection-induced aberrant immune responses. Genetic polymorphisms in Fc gamma receptor genes (FCGR) have been associated with GBS. We assessed whether polymorphisms rs1801274 in FCGR2A and rs396991 in FCGR3A were associated with GBS in a Brazilian population. We genotyped 141 GBS cases and 364 healthy controls from Brazil for both polymorphisms. The FCGR genotypes and alleles frequencies did not differ significantly between GBS and controls. In addition, there was no genetic association with either severity or clinical outcomes. We conclude that these FCGR polymorphisms are not associated with susceptibility to Guillain-Barré Syndrome in this Brazilian population. Copyright © 2016. Published by Elsevier B.V.

Genetic polymorphism of UDP-glucuronosyltransferase (UGT2B15) and glucuronidation of paracetamol in healthy population.

PubMed

Mehboob, Huma; Iqbal, Tahira; Jamil, Amer; Khaliq, Tanweer

2016-05-01

Inter individual variability in polymorphic UDP-glucuronosyltransferase (UGT2B15) has been associated with varied glucuronidation level. The present project was designed to determine the genetic polymorphism of UDP-glucuronosyltransferase (UGT2B15) and glucuronidation of paracetamol in healthy (male=59 and female=50) population. The association between genotype (UGT2B15) and phenotype (paracetamol glucuronidation) has been evaluated. According to trimodal model, genotypes and phenotypes were categorized as fast, intermediate and slow glucuronidators. Presence of wild type allele illustrated a UGT2B15 genotype as fast glucuronidator. The glucuronidation status was investigated by HPLC analysis of paracetamol. Ratio of paracetamol glucuronide to paracetamol was determined with two antimodes at glucuronidation ratio of 0.3 and 1.8. In our study, 7% and 12% of population was distributed as slow glucuronidators by phenotype and genotype, respectively and association between phenotype and genotype was good for analysis of glucuronidation status as displayed by kappa value (0.792).

Interaction of IFNL3 with insulin resistance, steatosis and lipid metabolism in chronic hepatitis C virus infection.

PubMed

Eslam, Mohammed; Booth, David R; George, Jacob; Ahlenstiel, Golo

2013-11-07

Metabolic changes are inextricably linked to chronic hepatitis C (CHC). Recently polymorphisms in the IFNL3 (IL28B) region have been shown to be strongly associated with spontaneous and treatment induced recovery from hepatitis C virus (HCV) infection. Further, circumstantial evidence suggests a link between IFNL3 single nucleotide polymorphisms and lipid metabolism, steatosis and insulin resistance in CHC. The emerging picture suggests that the responder genotypes of IFNL3 polymorphisms are associated with a higher serum lipid profile, and less frequent steatosis and insulin resistance. This review analyzes the current data regarding this interaction and its meaning for HCV pathogenesis and disease progression.

Association of the 5′-upstream regulatory region of the α7 nicotinic acetylcholine receptor subunit gene (CHRNA7) with schizophrenia

PubMed Central

Stephens, Sarah H.; Logel, Judith; Barton, Amanda; Franks, Alexis; Schultz, Jessica; Short, Margaret; Dickenson, Jane; James, Benjamin; Fingerlin, Tasha E.; Wagner, Brandie; Hodgkinson, Colin; Graw, Sharon; Ross, Randal G.; Freedman, Robert; Leonard, Sherry

2009-01-01

Background The α7 neuronal nicotinic acetylcholine receptor subunit gene (CHRNA7) is localized in a chromosomal region (15q14) linked to schizophrenia in multiple independent studies. CHRNA7 was selected as the best candidate gene in the region for a well-documented endophenotype of schizophrenia, the P50 sensory processing deficit, by genetic linkage and biochemical studies. Methods Subjects included Caucasian-Non Hispanic and African-American case-control subjects collected in Denver, and schizophrenic subjects from families in the NIMH Genetics Initiative on Schizophrenia. Thirty-five single nucleotide polymorphisms (SNPs) in the 5′-upstream regulatory region of CHRNA7 were genotyped for association with schizophrenia, and for smoking in schizophrenia. Results The rs3087454 SNP, located at position −1831 bp in the upstream regulatory region of CHRNA7, was significantly associated with schizophrenia in the case-control samples after multiple-testing correction (P = 0.0009, African American; P = 0.013, Caucasian-Non Hispanic); the association was supported in family members. There was nominal association of this SNP with smoking in schizophrenia. Conclusions The data support association of regulatory region polymorphisms in the CHRNA7 gene with schizophrenia. PMID:19181484

An Fe-S cluster in the conserved Cys-rich region in the catalytic subunit of FAD-dependent dehydrogenase complexes.

PubMed

Shiota, Masaki; Yamazaki, Tomohiko; Yoshimatsu, Keiichi; Kojima, Katsuhiro; Tsugawa, Wakako; Ferri, Stefano; Sode, Koji

2016-12-01

Several bacterial flavin adenine dinucleotide (FAD)-harboring dehydrogenase complexes comprise three distinct subunits: a catalytic subunit with FAD, a cytochrome c subunit containing three hemes, and a small subunit. Owing to the cytochrome c subunit, these dehydrogenase complexes have the potential to transfer electrons directly to an electrode. Despite various electrochemical applications and engineering studies of FAD-dependent dehydrogenase complexes, the intra/inter-molecular electron transfer pathway has not yet been revealed. In this study, we focused on the conserved Cys-rich region in the catalytic subunits using the catalytic subunit of FAD dependent glucose dehydrogenase complex (FADGDH) as a model, and site-directed mutagenesis and electron paramagnetic resonance (EPR) were performed. By co-expressing a hitch-hiker protein (γ-subunit) and a catalytic subunit (α-subunit), FADGDH γα complexes were prepared, and the properties of the catalytic subunit of both wild type and mutant FADGDHs were investigated. Substitution of the conserved Cys residues with Ser resulted in the loss of dye-mediated glucose dehydrogenase activity. ICP-AEM and EPR analyses of the wild-type FADGDH catalytic subunit revealed the presence of a 3Fe-4S-type iron-sulfur cluster, whereas none of the Ser-substituted mutants showed the EPR spectrum characteristic for this cluster. The results suggested that three Cys residues in the Cys-rich region constitute an iron-sulfur cluster that may play an important role in the electron transfer from FAD (intra-molecular) to the multi-heme cytochrome c subunit (inter-molecular) electron transfer pathway. These features appear to be conserved in the other three-subunit dehydrogenases having an FAD cofactor. Copyright © 2016 Elsevier B.V. All rights reserved.

Evolutionary relationships of lactate dehydrogenases (LDHs) from mammals, birds, an amphibian, fish, barley, and bacteria: LDH cDNA sequences from Xenopus, pig, and rat.

PubMed Central

Tsuji, S; Qureshi, M A; Hou, E W; Fitch, W M; Li, S S

1994-01-01

The nucleotide sequences of the cDNAs encoding LDH (EC 1.1.1.27) subunits LDH-A (muscle), LDH-B (liver), and LDH-C (oocyte) from Xenopus laevis, LDH-A (muscle) and LDH-B (heart) from pig, and LDH-B (heart) and LDH-C (testis) from rat were determined. These seven newly deduced amino acid sequences and 22 other published LDH sequences, and three unpublished fish LDH-A sequences kindly provided by G. N. Somero and D. A. Powers, were used to construct the most parsimonious phylogenetic tree of these 32 LDH subunits from mammals, birds, an amphibian, fish, barley, and bacteria. There have been at least six LDH gene duplications among the vertebrates. The Xenopus LDH-A, LDH-B, and LDH-C subunits are most closely related to each other and then are more closely related to vertebrate LDH-B than LDH-A. Three fish LDH-As, as well as a single LDH of lamprey, also seem to be more related to vertebrate LDH-B than to land vertebrate LDH-A. The mammalian LDH-C (testis) subunit appears to have diverged very early, prior to the divergence of vertebrate LDH-A and LDH-B subunits, as reported previously. Images PMID:7937776

A polymorphism in a transporter of testosterone is a determinant of androgen independence in prostate cancer.

PubMed

Sharifi, Nima; Hamada, Akinobu; Sissung, Tristan; Danesi, Romano; Venzon, David; Baum, Caitlin; Gulley, James L; Price, Douglas K; Dahut, William L; Figg, William D

2008-08-05

To determine if patients with advanced prostate cancer carrying a polymorphism that codes for a more active testosterone transporter have less durable responses to androgen-deprivation therapy (ADT) than patients not carrying this polymorphism. We previously determined that a polymorphism in SLCO1B3 affects testosterone transport and that those men who have at least one wild-type T allele at the 334 T > G polymorphism in this gene have a shorter survival. We hypothesized that the T allele which increases testosterone transport would be associated with a shorter interval from ADT to androgen independence. We examined the association between this SLCO1B3 polymorphism and time from ADT to androgen independence, ADT to prostate-specific antigen (PSA) nadir and PSA nadir to androgen independence in 68 Caucasian patients with advanced prostate cancer who were treated with ADT with metastatic disease (D2) or biochemical failure with no metastatic disease (D0). When examined separately, patients in the individual stages tended to have a shorter time to androgen independence with the T allele in the D0 (P = 0.11) and D2 (P = 0.18) groups. Combining these groups and stratifying by stage yielded a statistically significant shorter time to androgen independence with the T allele (P = 0.048). A polymorphism in a transporter that increases testosterone import is associated with a shorter time to androgen independence in patients with prostate cancer who are treated with ADT.

Platelet GP IIIA polymorphism HPA-1 (PLA1/2) is associated with hypertension as the primary cause for end-stage renal disease in hemodialysis patients from Greece.

PubMed

Chiras, Theodore; Papadakis, Emmanuel D; Katopodi, Aggeliki; Chatzianesti, Efrosini; Fourtounas, Kostas; Papakonstantinou, Stamatina; Theodoropoulos, Ilias; Dakouras, Anastasios; Zerefos, Nikolas; Valis, Dimitrios; Tzanatos-Exarchou, Helen

2009-01-01

Human platelets carry membrane glycoproteins that control platelet aggregation and activation. A number of clinical studies have suggested that certain polymorphisms of genes encoding these proteins increase the risk for cardiovascular disease. The frequency of gene polymorphisms for the four most common platelet glycoproteins (HPA 1, 2, 3 and 5) was examined and correlated with the primary cause of end-stage renal disease (ESRD) in Greek patients on HD. Fifty-five (55) patients on chronic maintenance haemodialysis (HD) (22 female, 33 male), aged from 23- to 87-years-old, (mean age 66 years), being on dialysis for 53 +/- 34 months, were included in the study. HPA-1, -2, -3, and -5 genotyping was performed using polymerase chain reaction (PCR) amplification with sequence-specific primers (PCR-SSP). Calculated relative frequencies of the alleles were as follows: HPA-1a/b 0.81/0.19, HPA-2a/b 0.92/0.08, HPA-3a/b 0.62/0.38 and HPA-5a/b 0.93/0.07. There was a statistically significant association between the HPA-1b allele and hypertension as the primary cause of ESRD (65% of patients with hypertension vs 23% of all other patients carried the HPA-1b allele, p=0.02, Fisher's exact test). The results suggest that Greek carriers of the HPA-1b allele with hypertension may be at increased risk for developing end-stage renal disease.

Impact of HSD11B1 polymorphisms on BMI and components of the metabolic syndrome in patients receiving psychotropic treatments.

PubMed

Quteineh, Lina; Vandenberghe, Frederik; Saigi Morgui, Nuria; Delacrétaz, Aurélie; Choong, Eva; Gholam-Rezaee, Mehdi; Magistretti, Pierre; Bondolfi, Guido; Von Gunten, Armin; Preisig, Martin; Castelao, Enrique; Vollenweider, Peter; Waeber, Gerard; Bochud, Murielle; Kutalik, Zoltán; Conus, Philippe; Eap, Chin B

2015-05-01

Metabolic syndrome (MetS) associated with psychiatric disorders and psychotropic treatments represents a major health issue. 11β-Hydroxysteroid dehydrogenase type 1 (11β-HSD1) is an enzyme that catalyzes tissue regeneration of active cortisol from cortisone. Elevated enzymatic activity of 11β-HSD1 may lead to the development of MetS. We investigated the association between seven HSD11B1 gene (encoding 11β-HSD1) polymorphisms and BMI and MetS components in a psychiatric sample treated with potential weight gain-inducing psychotropic drugs (n=478). The polymorphisms that survived Bonferroni correction were analyzed in two independent psychiatric samples (nR1=168, nR2=188) and in several large population-based samples (n1=5338; n2=123 865; n3>100 000). HSD11B1 rs846910-A, rs375319-A, and rs4844488-G allele carriers were found to be associated with lower BMI, waist circumference, and diastolic blood pressure compared with the reference genotype (Pcorrected<0.05). These associations were exclusively detected in women (n=257) with more than 3.1 kg/m, 7.5 cm, and 4.2 mmHg lower BMI, waist circumference, and diastolic blood pressure, respectively, in rs846910-A, rs375319-A, and rs4844488-G allele carriers compared with noncarriers (Pcorrected<0.05). Conversely, carriers of the rs846906-T allele had significantly higher waist circumference and triglycerides and lower high-density lipoprotein-cholesterol exclusively in men (Pcorrected=0.028). The rs846906-T allele was also associated with a higher risk of MetS at 3 months of follow-up (odds ratio: 3.31, 95% confidence interval: 1.53-7.17, Pcorrected=0.014). No association was observed between HSD11B1 polymorphisms and BMI and MetS components in the population-based samples. Our results indicate that HSD11B1 polymorphisms may contribute toward the development of MetS in psychiatric patients treated with potential weight gain-inducing psychotropic drugs, but do not play a significant role in the general population.

Cytidine deaminases from B. subtilis and E. coli: compensating effects of changing zinc coordination and quaternary structure.

PubMed

Carlow, D C; Carter, C W; Mejlhede, N; Neuhard, J; Wolfenden, R

1999-09-21

Cytidine deaminase from E. coli is a dimer of identical subunits (M(r) = 31 540), each containing a single zinc atom. Cytidine deaminase from B. subtilis is a tetramer of identical subunits (M(r) = 14 800). After purification from an overexpressing strain, the enzyme from B. subtilis is found to contain a single atom of zinc per enzyme subunit by flame atomic absorption spectroscopy. Fluorescence titration indicates that each of the four subunits contains a binding site for the transition state analogue inhibitor 5-fluoro-3,4-dihydrouridine. A region of amino acid sequence homology, containing residues that are involved in zinc coordination in the enzyme from E. coli, strongly suggests that in the enzyme from B. subtilis, zinc is coordinated by the thiolate side chains of three cysteine residues (Cys-53, Cys-86, and Cys-89) [Song, B. H., and Neuhard, J. (1989) Mol. Gen. Genet. 216, 462-468]. This pattern of zinc coordination appears to be novel for a hydrolytic enzyme, and might be expected to reduce the reactivity of the active site substantially compared with that of the enzyme from E. coli (His-102, Cys-129, and Cys-132). Instead, the B. subtilis and E. coli enzymes are found to be similar in their activities, and also in their relative binding affinities for a series of structurally related inhibitors with binding affinities that span a range of 6 orders of magnitude. In addition, the apparent pK(a) value of the active site is shifted upward by less than 1 unit. Sequence alignments, together with model building, suggest one possible mechanism of compensation.

Association of GABA(B)R1 receptor gene polymorphism with obstructive sleep apnea syndrome.

PubMed

Bayazit, Yildirim A; Yilmaz, Metin; Kokturk, Oguz; Erdal, M Emin; Ciftci, Tansu; Gokdogan, Tuba; Kemaloglu, Yusuf; Ileri, Fikret

2007-01-01

GABA(B)R (gamma-amino butyric acid B receptor)-mediated neurotransmission has been implicated in the pathophysiology of a variety of neuropsychiatric disorders. GABA(B)R1 gene variants were identified by single-strand conformation analysis. The nucleotide exchanges cause a substitution of alanine to valine in exon 1a1 (Ala20Val), a substitution of glycine to serine in exon 7 (Gly489Ser) and a silent C to G nucleotide exchange encoding the amino acid phenylalanine in exon 11 (Phe658Phe). The significance of GABA(B)R1a gene polymorphism in obstructive sleep apnea syndrome (OSAS) as well as the association of these polymorphisms with the polysomnography findings in OSAS patients are not known. In this study, we aimed to assess the significance of 3 different GABA(B)R1 gene polymorphisms (Ala20Val, Gly489Ser and Phe658Phe) in OSAS. Seventy-five patients (23 female and 52 male) with OSAS and 99 healthy volunteers (51 female, 48 male) were included in the study to assess Ala20Val, Gly489Ser and Phe658Phe polymorphisms of the GABA(B)R1 gene. For the Ala20Val variants, there was no significant difference between the genotypes and allele frequencies of the patients and controls, nor between both genders (p > 0.05). For Phe658Phe polymorphism, there was no significant difference between genotypes and allele frequencies of the patients and controls (p > 0.05). However, the C/C genotype was overrepresented and the T/C genotype was less frequent in male than female patients (p = 0.03). The C/C genotype was overrepresented and the T/C genotype was less frequent in male patients than male controls (p = 0.01). For GABA(B)R1-Gly489Ser polymorphism, all of the patients and controls had G/G genotype. The apnea arousal index scores of the male patients with C/C genotype were significantly higher than in the patients with C/T genotype (p = 0.01). The percent total sleep time in non-REM 1 scores of the male patients with T/T genotype were significantly higher than in the patients with T/C genotype (p = 0.021). The percent total sleep time in non-REM 2 scores of the female patients with C/C genotype were significantly higher than in the patients with C/T genotype (p = 0.006). The Ala20Val polymorphism of the GABA(B)R1 gene may be associated with OSAS, whereas Gly489Ser polymorphism does not seem to be involved in OSAS. The C/C variant of the Phe658Phe polymorphism GABA(B)R1 gene seems associated with the occurrence of OSAS and is also associated with some sleep related parameters (apnea arousal index and percent total sleep time in non-REM) recorded by polysomnography. Copyright (c) 2007 S. Karger AG, Basel.

ARID5B, CEBPE and PIP4K2A Germline Genetic Polymorphisms and Risk of Childhood Acute Lymphoblastic Leukemia in Mexican Patients: A MIGICCL Study.

PubMed

Bekker-Méndez, Vilma Carolina; Núñez-Enríquez, Juan Carlos; Torres Escalante, José Luis; Alvarez-Olmos, Enrique; González-Montalvoc, Pablo Miguel; Jiménez-Hernández, Elva; Sansón, Aurora Medina; Leal, Yelda A; Ramos-Cervantes, María Teresa; Guerra-Castillo, Francisco Xavier; Ortiz-Maganda, Mónica Patricia; Flores-Lujano, Janet; Pérez-Saldivar, Maria Luisa; Velazquez-Aviña, Martha Margarita; Bolea-Murga, Victoria; Torres-Nava, José Refugio; Amador-Sanchez, Raquel; Solis-Labastida, Karina Anastacia; Rámirez-Bello, Julian; Fragoso, José Manuel; Mejía-Aranguré, Juan Manuel

2016-11-01

Childhood acute lymphoblastic leukemia (ALL) is the leading cause of childhood cancer-related deaths worldwide. Multiples studies have shown that ALL seems to be originated by an interaction between environmental and genetic susceptibility factors. The ARID5B polymorphisms are among the most reproducible ALL associated-risk alleles in different populations. The aim of the present study was to examine the contribution of ARID5B, CEBPE, and PIP4K2 risk alleles for the development of ALL in children from Mexico City and Yucatan, Mexico. A study was conducted with a total of 761 unrelated subjects. Two hundred eighty five ALL cases (111 from Yucatan and 174 from Mexico City) and 476 healthy subjects. Genotyping included the rs7088318 (PIP4K2A), rs10821936 (ARID5B), rs7089424 (ARID5B) and rs2239633 (CEBPE) polymorphisms. Associations between ALL and rs10821936 and rs7089424 ARID5B SNPs were found (OR = 1.9, 95% CI (1.5-2.4) and OR = 2.0, 95% CI (1.6-2.5), respectively). Moreover, a higher risk was observed in the homozygous risk genotypes of carriers from Mexico City (OR = 3.1, 95% CI (2.0-4.9) and OR 3.1, CI 95% (2.0-4.8), respectively). Otherwise, the rs7088318 (PIP4K2A) and rs2239633 (CEBPE) polymorphisms were not associated with ALL risk. Our analysis suggests that ARID5B confers risk for childhood ALL in a Mexican population. Copyright © 2016 IMSS. Published by Elsevier Inc. All rights reserved.

Aldehyde dehydrogenase 2 polymorphism for development to hepatocellular carcinoma in East Asian alcoholic liver cirrhosis.

PubMed

Abe, Hiroshi; Aida, Yuta; Seki, Nobuyoshi; Sugita, Tomonori; Tomita, Yoichi; Nagano, Tomohisa; Itagaki, Munenori; Sutoh, Satoshi; Nagatsuma, Keisuke; Itoh, Kyoko; Matsuura, Tomokazu; Aizawa, Yoshio

2015-09-01

We aimed to clarify the influences of aldehyde dehydrogenase 2 (ALDH2), alcohol dehydrogenase 1B (ADH1B) polymorphisms, and ethanol consumption profile to hepatocellular carcinoma (HCC) development in alcoholic liver cirrhosis without chronic hepatitis B and C virus infection (non-B non-C). Of 236 freshly diagnosed non-B non-C alcoholic liver cirrhosis patients, 67 were diagnosed as HCC and the remaining 169 as not having HCC. The relationship between the genetic polymorphisms and development to HCC were evaluated in well-matched patients with HCC (HCC group, n = 67) and without HCC (non-HCC group, n = 67) using propensity scores in age, sex, and prevalence of diabetes mellitus. Daily amount of ethanol consumption was significantly lower (P = 0.005), and consumptive period was significantly longer (P = 0.003) in HCC group than non-HCC group. Of 134 well-matched patients, 113 (84.3%) had ALDH2*1/*1 genotype and 21 (15.7%) had ALDH2*1/*2 genotype. In HCC development, consumptive long period (P = 0.007) and carrying ALDH2*1/*2 genotype (P = 0.026) were identified as significant factors independently participated, while there was no relation to ADH1B polymorphism. In addition, consumptive period was significantly longer in HCC group than non-HCC group in ALDH2*1/*1 genotype patients (P = 0.0005), while there was no difference in profile of ethanol consumption in ALDH2*1/*2 genotype patients. Among HCC group, daily (P = 3.78 × 10(-6) ) and cumulative amount (P = 4.89 × 10(-6) ) of ethanol consumption were significantly higher in ALDH2*1/*1 genotype patients than ALDH2*1/*2 genotype patients. In alcoholic liver cirrhosis, investigations of ALDH2 polymorphism and ethanol consumption profile are useful for prediction of HCC development. © 2015 Journal of Gastroenterology and Hepatology Foundation and Wiley Publishing Asia Pty Ltd.

Natural Endophytic Occurrence of Acetobacter diazotrophicus in Pineapple Plants.

PubMed

Tapia-Hernández; Bustillos-Cristales; Jiménez-Salgado; Caballero-Mellado; Fuentes-Ramírez

2000-01-01

The presence of endophytic Acetobacter diazotrophicus was tested for pineapple plants (Ananas comosus [L.] Merr.) grown in the field. Diazotrophic bacteria were isolated from the inner tissues of surface sterilized roots, stems, and leaves of pineapple plants. Phenotypic tests permitted the selection of presumptive nitrogen-fixing A. diazotrophicus isolates. Restriction fragment length polymorphisms (RFLPs) of small subunit (SSU) rDNA using total DNA digested with endonuclease SphI and with endonuclease NcoI, hybridizations of RNA with an A. diazotrophicus large subunit (LSU) rRNA specific probe, as well as patterns in denaturing protein electrophoresis (SDS-PAGE) and multilocus enzyme tests allowed the identification of A. diazotrophicus isolates. High frequencies of isolation were obtained from propagative buds that had not been nitrogen-fertilized, and lower frequencies from 3-month-old plants that had been nitrogen-fertilized. No isolates were recovered from 5- to 7-month-old nitrogen-fertilized plants. All the A. diazotrophicus isolates recovered from pineapple plants belonged to the multilocus genotype which shows the most extensive distribution among all host species previously analyzed.

Crucial roles of the CHRNB3-CHRNA6 gene cluster on chromosome 8 in nicotine dependence: update and subjects for future research.

PubMed

Wen, L; Yang, Z; Cui, W; Li, M D

2016-06-21

Cigarette smoking is a leading cause of preventable death throughout the world. Nicotine, the primary addictive compound in tobacco, plays a vital role in the initiation and maintenance of its use. Nicotine exerts its pharmacological roles through nicotinic acetylcholine receptors (nAChRs), which are ligand-gated ion channels consisting of five membrane-spanning subunits. Besides the CHRNA4, CHRNB2 and CHRNA5/A3/B4 cluster on chromosome 15, which has been investigated intensively, recent evidence from both genome-wide association studies and candidate gene-based association studies has revealed the crucial roles of the CHRNB3-CHRNA6 gene cluster on chromosome 8 in nicotine dependence (ND). These studies demonstrate two distinct loci within this region. The first one is tagged by rs13277254, upstream of the CHRNB3 gene, and the other is tagged by rs4952, a coding single nucleotide polymorphism in exon 5 of that gene. Functional studies by genetic manipulation in mice have shown that α6*-nAChRs, located in the ventral tegmental area (VTA), are of great importance in controlling nicotine self-administration. However, when the α6 subunit is selectively re-expressed in the VTA of the α6(-/-) mouse by a lentiviral vector, the reinforcing property of nicotine is restored. To further determine the role of α6*-nAChRs in the process of nicotine-induced reward and withdrawal, genetic knock-in strains have been examined, which showed that replacement of Leu with Ser in the 9' residue in the M2 domain of α6 produces nicotine-hypersensitive mice (α6 L9'S) with enhanced dopamine release. Moreover, nicotine-induced upregulation may be another ingredient in the pathology of nicotine addiction although the effect of chronic nicotine exposure on the expression of α6-containing receptors is controversial. To gain a better understanding of the pathological processes underlying ND and ND-related behaviors and to promote the development of effective smoking cessation therapies, we here present the most recent studies concerning the genetic effects of the CHRNB3-CHRNA6 gene cluster in ND.

Thermostable Cross-Protective Subunit Vaccine against Brucella Species

PubMed Central

Barabé, Nicole D.; Grigat, Michelle L.; Lee, William E.; Poirier, Robert T.; Jager, Scott J.; Berger, Bradley J.

2014-01-01

A subunit vaccine candidate was produced from Brucella suis 145 (biovar 4; expressing both the A antigen of Brucella abortus and the M antigen of Brucella melitensis). The preparation consisted mostly of polysaccharide (PS; >90% [wt/wt]; both cell-associated PS and exo-PS were combined) and a small amount of protein (1 to 3%) with no apparent nucleic acids. Vaccinated mice were protected (these had a statistically significant reduction in bacterial colonization compared to that of unvaccinated controls) when challenged with representative strains of three Brucella species most pathogenic for humans, i.e., B. abortus, B. melitensis, and B. suis. As little as 1 ng of the vaccine, without added adjuvant, protected mice against B. suis 145 infection (5 × 105 CFU), and a single injection of 1 μg of this subunit vaccine protected mice from B. suis 145 challenge for at least 14 months. A single immunization induced a serum IgG response to Brucella antigens that remained elevated for up to 9 weeks. The use of heat (i.e., boiling-water bath, autoclaving) in the vaccine preparation showed that it was thermostable. This method also ensured safety and security. The vaccine produced was immunogenic and highly protective against multiple strains of Brucella and represents a promising candidate for further evaluation. PMID:25320267

Mediated Plastid RNA Editing in Plant Immunity

PubMed Central

García-Andrade, Javier; Ramírez, Vicente; López, Ana; Vera, Pablo

2013-01-01

Plant regulatory circuits coordinating nuclear and plastid gene expression have evolved in response to external stimuli. RNA editing is one of such control mechanisms. We determined the Arabidopsis nuclear-encoded homeodomain-containing protein OCP3 is incorporated into the chloroplast, and contributes to control over the extent of ndhB transcript editing. ndhB encodes the B subunit of the chloroplast NADH dehydrogenase-like complex (NDH) involved in cyclic electron flow (CEF) around photosystem I. In ocp3 mutant strains, ndhB editing efficiency decays, CEF is impaired and disease resistance to fungal pathogens substantially enhanced, a process recapitulated in plants defective in editing plastid RNAs encoding NDH complex subunits due to mutations in previously described nuclear-encoded pentatricopeptide-related proteins (i.e. CRR21, CRR2). Furthermore, we observed that following a pathogenic challenge, wild type plants respond with editing inhibition of ndhB transcript. In parallel, rapid destabilization of the plastidial NDH complex is also observed in the plant following perception of a pathogenic cue. Therefore, NDH complex activity and plant immunity appear as interlinked processes. PMID:24204264

Association of GSK3B With Alzheimer Disease and Frontotemporal Dementia

PubMed Central

Schaffer, Barbara A. J.; Bertram, Lars; Miller, Bruce L.; Mullin, Kristina; Weintraub, Sandra; Johnson, Nancy; Bigio, Eileen H.; Mesulam, Marsel; Wiedau-Pazos, Martina; Jackson, George R.; Cummings, Jeffrey L.; Cantor, Rita M.; Levey, Allan I.; Tanzi, Rudolph E.; Geschwind, Daniel H.

2009-01-01

Background Deposits of abnormally hyperphosphorylated tau are a hallmark of several dementias, including Alzheimer disease (AD), and about 10% of familial frontotemporal dementia (FTD) cases are caused by mutations in the tau gene. As a known tau kinase, GSK3B is a promising candidate gene in the remaining cases of FTD and in AD, for which tau mutations have not been found. Objective To examine the promoter of GSK3B and all 12 exons, including the surrounding intronic sequence, in patients with FTD, patients with AD, and aged healthy subjects to identify single-nucleotide polymorphisms associated with disease. Design, Setting, and Participants Single-nucleotide polymorphism frequency was examined in a case-control cohort of 48 patients with probable AD, 102 patients with FTD, 38 patients with primary progressive aphasia, and 85 aged healthy subjects. Results were followed up in 2 independent AD family samples consisting of 437 multiplex families with AD (National Institute of Mental Health Genetics Initiative AD Study) or 150 sibships discordant for AD (Consortium on Alzheimer’s Genetics Study). Results Several rare sequence variants in GSK3B were identified in the case-control study. An intronic polymorphism (IVS2−68G>A) occurred at more than twice the frequency among patients with FTD (10.8%) and patients with AD (14.6%) than in aged healthy subjects (4.1%). The polymorphism showed association with disease in both follow-up samples independently, although only the Consortium on Alzheimer’s Genetics sample showed the same direction of association as the case-control sample. Conclusions To our knowledge, this is the first evidence that a gene known to be involved in tau phosphorylation, GSK3B, is associated with risk for primary neurodegenerative dementias. This supports previous work in animal models suggesting that such genes are therapeutic targets. PMID:18852354

ErbB polymorphisms: insights and implications for response to targeted cancer therapeutics.

PubMed

Alaoui-Jamali, Moulay A; Morand, Grégoire B; da Silva, Sabrina Daniela

2015-01-01

Advances in high-throughput genomic-scanning have expanded the repertory of genetic variations in DNA sequences encoding ErbB tyrosine kinase receptors in humans, including single nucleotide polymorphisms (SNPs), polymorphic repetitive elements, microsatellite variations, small-scale insertions and deletions. The ErbB family members: EGFR, ErbB2, ErbB3, and ErbB4 receptors are established as drivers of many aspects of tumor initiation and progression to metastasis. This knowledge has provided rationales for the development of an arsenal of anti-ErbB therapeutics, ranging from small molecule kinase inhibitors to monoclonal antibodies. Anti-ErbB agents are becoming the cornerstone therapeutics for the management of cancers that overexpress hyperactive variants of ErbB receptors, in particular ErbB2-positive breast cancer and non-small cell lung carcinomas. However, their clinical benefit has been limited to a subset of patients due to a wide heterogeneity in drug response despite the expression of the ErbB targets, attributed to intrinsic (primary) and to acquired (secondary) resistance. Somatic mutations in ErbB tyrosine kinase domains have been extensively investigated in preclinical and clinical setting as determinants for either high sensitivity or resistance to anti-ErbB therapeutics. In contrast, only scant information is available on the impact of SNPs, which are widespread in genes encoding ErbB receptors, on receptor structure and activity, and their predictive values for drug susceptibility. This review aims to briefly update polymorphic variations in genes encoding ErbB receptors based on recent advances in deep sequencing technologies, and to address challenging issues for a better understanding of the functional impact of single versus combined SNPs in ErbB genes to receptor topology, receptor-drug interaction, and drug susceptibility. The potential of exploiting SNPs in the era of stratified targeted therapeutics is discussed.

Direct molecular interactions between Beclin 1 and the canonical NFκB activation pathway.

PubMed

Niso-Santano, Mireia; Criollo, Alfredo; Malik, Shoaib Ahmad; Michaud, Michael; Morselli, Eugenia; Mariño, Guillermo; Lachkar, Sylvie; Galluzzi, Lorenzo; Maiuri, Maria Chaira; Kroemer, Guido

2012-02-01

General (macro)autophagy and the activation of NFκB constitute prominent responses to a large array of intracellular and extracellular stress conditions. The depletion of any of the three subunits of the inhibitor of NFκB (IκB) kinase (IKKα, IKKβ, IKKγ/NEMO), each of which is essential for the canonical NFκB activation pathway, limits autophagy induction by physiological or pharmacological triggers, while constitutive active IKK subunits suffice to stimulate autophagy. The activation of IKK usually relies on TGFβ-activated kinase 1 (TAK1), which is also necessary for the optimal induction of autophagy in multiple settings. TAK1 interacts with two structurally similar co-activators, TAK1-binding proteins 2 and 3 (TAB2 and TAB3). Importantly, in resting conditions both TAB2 and TAB3 bind the essential autophagic factor Beclin 1, but not TAK1. In response to pro-autophagic stimuli, TAB2 and TAB3 dissociate from Beclin 1 and engage in stimulatory interactions with TAK1. The inhibitory interaction between TABs and Beclin 1 is mediated by their coiled-coil domains (CCDs). Accordingly, the overexpression of either TAB2 or TAB3 CCD stimulates Beclin 1- and TAK1-dependent autophagy. These results point to the existence of a direct molecular crosstalk between the canonical NFκB activation pathway and the autophagic core machinery that guarantees the coordinated induction of these processes in response to stress.

The synthesis of mycosporine-like amino acids (MAAs) by cultured, symbiotic dinoflagellates.

PubMed

T Banaszak1 A; LaJeunesse; Trench

2000-06-28

We tested the hypothesis that there is a relation between phylotypes (phylogenetic types, as determined by restriction fragment length polymorphism (RFLP) and partial sequence analysis of the small subunit ribosomal RNA gene (SSUrDNA)) and the synthesis of mycosporine-like amino acids (MAAs) by symbiotic dinoflagellates under the influence of ultraviolet radiation (UV-B/A) and photosynthetically active radiation (PAR). We exposed 27 isolates of symbiotic dinoflagellates simultaneously to UV-B/A and PAR, and subsequently determined the MAAs present in cell extracts and in the media. The algae used included 24 isolates of Symbiodinium spp. originating from jellyfishes, sea anemones, zoanthids, scleractinians, octocorals, and bivalves, and three others in the genera Gymnodinium, Gloeodinium and Amphidinium from a jellyfish, an hydrocoral and a flatworm, respectively. In this study, all of the phylotype A Symbiodinium spp. synthesized up to three identified MAAs. None of the 11 cultured phylotypes B and C Symbiodinium spp. synthesized MAAs. The three non-Symbiodinium symbionts also synthesized up to three MAAs. The results support a conclusion that phylotype A Symbiodinium spp. have a high predilection for the synthesis of MAAs, while phylotypes B and C do not. Synthesis of MAAs by symbiotic dinoflagellates in culture does not appear to relate directly to depths or to the UV exposure regimes from which the consortia were collected.

HLA-G+3027 polymorphism is associated with tumor relapse in pediatric Hodgkin's lymphoma.

PubMed

De Re, Valli; Caggiari, Laura; Mussolin, Lara; d'Amore, Emanuele Stefano; Famengo, Barbara; De Zorzi, Mariangela; Martina, Lia; Elia, Caterina; Pillon, Marta; Santoro, Nicola; Muggeo, Paola; Buffardi, Salvatore; Bianchi, Maurizio; Sala, Alessandra; Farruggia, Piero; Vinti, Luciana; Carosella, Edgardo D; Burnelli, Roberta; Mascarin, Maurizio

2017-12-01

In this study, we tested whether polymorphisms in human leukocyte antigen G (HLA-G) were associated with event-free survival (EFS) in pediatric Hodgkin's lymphoma (HL). We evaluated the association of HLA-G 3'-UTR polymorphisms with EFS in 113 pediatric HL patients treated using the AIEOP LH-2004 protocol. Patients with the +3027-C/A genotype (rs17179101, UTR-7 haplotype) showed lower EFS than those with the +3027-C/C genotype (HR= 3.23, 95%CI: 0.99-10.54, P=0.012). Female patients and systemic B symptomatic patients with the HLA-G +3027 polymorphism showed lower EFS. Multivariate analysis showed that the +3027-A polymorphism (HR 3.17, 95%CI 1.16-8.66, P=0.025) was an independent prognostic factor. Immunohistochemical analysis showed that HL cells from patients with the +3027-C/A genotype did not express HLA-G. Moreover, HLA-G +3027 polymorphism improved EFS prediction when added to the algorithm for therapeutic group classification of pediatric HL patients. Our findings suggest HLA-G +3027 polymorphism is a prognostic marker in pediatric HL patients undergoing treatment according to LH-2004 protocol.

Polymorphs and polymorphic cocrystals of temozolomide.

PubMed

Babu, N Jagadeesh; Reddy, L Sreenivas; Aitipamula, Srinivasulu; Nangia, Ashwini

2008-07-07

Crystal polymorphism in the antitumor drug temozolomide (TMZ), cocrystals of TMZ with 4,4'-bipyridine-N,N'-dioxide (BPNO), and solid-state stability were studied. Apart from a known X-ray crystal structure of TMZ (form 1), two new crystalline modifications, forms 2 and 3, were obtained during attempted cocrystallization with carbamazepine and 3-hydroxypyridine-N-oxide. Conformers A and B of the drug molecule are stabilized by intramolecular amide N--HN(imidazole) and N--HN(tetrazine) interactions. The stable conformer A is present in forms 1 and 2, whereas both conformers crystallized in form 3. Preparation of polymorphic cocrystals I and II (TMZBPNO 1:0.5 and 2:1) were optimized by using solution crystallization and grinding methods. The metastable nature of polymorph 2 and cocrystal II is ascribed to unused hydrogen-bond donors/acceptors in the crystal structure. The intramolecularly bonded amide N-H donor in the less stable structure makes additional intermolecular bonds with the tetrazine C==O group and the imidazole N atom in stable polymorph 1 and cocrystal I, respectively. All available hydrogen-bond donors and acceptors are used to make intermolecular hydrogen bonds in the stable crystalline form. Synthon polymorphism and crystal stability are discussed in terms of hydrogen-bond reorganization.

Genetic polymorphisms, hormone levels, and hot flashes in midlife women.

PubMed

Schilling, Chrissy; Gallicchio, Lisa; Miller, Susan R; Langenberg, Patricia; Zacur, Howard; Flaws, Jodi A

2007-06-20

Hot flashes disrupt the lives of millions of women each year. Although hot flashes are a public health concern, little is known about risk factors that predispose women to hot flashes. Thus, the objective of this study was to examine whether sex steroid hormone levels and genetic polymorphisms in hormone biosynthesis and degradation enzymes are associated with the risk of hot flashes. In a cross-sectional study design, midlife women aged 45-54 years (n=639) were recruited from Baltimore and its surrounding counties. Participants completed a questionnaire and donated a blood sample for steroid hormone analysis and genotyping. The associations between genetic polymorphisms and hormone levels, as well as the associations between genetic polymorphisms, hormone levels, and hot flashes were examined using statistical models. A polymorphism in CYP1B1 was associated with lower dehydroepiandrosterone-sulfate (DHEA-S) and progesterone levels, while a polymorphism in CYP19 (aromatase) was associated with higher testosterone and DHEA-S levels. Lower progesterone and sex hormone binding globulin levels, lower free estradiol index, and a higher ratio of total androgens to total estrogens were associated with the experiencing of hot flashes. A polymorphism in CYP1B1 and a polymorphism in 3betaHSD were both associated with hot flashes. Some genetic polymorphisms may be associated with altered levels of hormones in midlife women. Further, selected genetic polymorphisms and altered hormone levels may be associated with the risk of hot flashes in midlife women.

Evaluation of the influence of alcohol dehydrogenase polymorphisms on alcohol elimination rates in African Americans.

PubMed

Marshall, Vanessa J; Ramchandani, Vijay A; Kalu, Nnenna; Kwagyan, John; Scott, Denise M; Ferguson, Clifford L; Taylor, Robert E

2014-01-01

The relationship between alcohol dehydrogenase (ADH) polymorphisms and alcohol use disorders in populations of African descent has not been clearly established. This study examined the effect of ADH1B polymorphisms on alcohol metabolism and subjective response, following intravenous (IV) alcohol administration, and the influence of gender, recent drinking history, and family history of alcoholism (FHA), in nondependent African American drinkers. The sample included eighty-seven 21- to 35-year-old, light social drinkers of African descent. Participants included 39 sib pairs, 2 sibships with 3 siblings each, and 3 individuals who were not part of a sibship. Participants received infusions via the use of the clamp method that refers to the goal of controlling breath alcohol concentration in 2 randomized sessions at 0.06 g% ethanol and 0 mg% (placebo), and a battery of subjective scales at predefined time points. Dependent measures included alcohol elimination rates (AERs), alcohol disappearance rates (ADRs), subjective measures peak scores, and area under the curve. General linear model and mixed models were performed to examine the relationship between ADH1B genotype, dependent measures, and influence of covariates. Participants with ADH1B1/1 genotypes showed higher number of drinks (p = 0.023) and drinks per drinking day (p = 0.009) compared with the persons with ADH1B1/3 genotype. AER (adjusted for body weight) was higher in ADH1B*1 homozygotes (p = 0.045) compared with ADH1B1/3 heterozygotes. ADR differed significantly between males and females (p = 0.002), regardless of body weight (p = 0.004) and lean body mass (p < 0.001) adjustments. Although a few subjective measures differed across genotype, all measures were higher in alcohol sessions compared with placebo sessions (p < 0.001). These observations were mediated by drinks per drinking day, gender, and FHA. ADH1B polymorphism had a marginal effect on alcohol pharmacokinetics following IV alcohol administration in nondependent drinkers of African descent. Session (alcohol vs. placebo) and ADH1B genotype did, however, influence subjective response to alcohol with some variation by gender, FHA, and drinks per drinking day. Copyright © 2013 by the Research Society on Alcoholism.

Genetic polymorphisms of ADH1B, ADH1C and ALDH2 in Turkish alcoholics: lack of association with alcoholism and alcoholic cirrhosis.

PubMed

Vatansever, Sezgin; Tekin, Fatih; Salman, Esin; Altintoprak, Ender; Coskunol, Hakan; Akarca, Ulus Salih

2015-05-17

No data exists regarding the alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) gene polymorphisms in Turkish alcoholic cirrhotics. We studied the polymorphisms of ADH1B, ADH1C and ALDH2 genes in alcoholic cirrhotics and compared the results with non-cirrhotic alcoholics and healthy volunteers. Overall, 237 subjects were included for the study: 156 alcoholic patients (78 cirrhotics, 78 non-cirrhotic alcoholics) and 81 healthy volunteers. Three different single-nucleotide-polymorphism genotyping methods were used. ADH1C genotyping was performed using a polymerase chain reaction-restriction fragment length polymorphism method. The identified ADH1C genotypes were named according to the presence or absence of the enzyme restriction sites. ADH1B (Arg47Hys) genotyping was performed using the allele specific primer extension method, and ALDH2 (Glu487Lys) genotyping was performed by a multiplex polymerase chain reaction using two allele-specific primer pairs. For ADH1B, the frequency of allele *1 in the cirrhotics, non-cirrhotic alcoholics and healthy volunteers was 97.4%, 94.9% and 99.4%, respectively. For ADH1C, the frequency of allele *1 in the cirrhotics, non-cirrhotic alcoholics and healthy volunteers was 47%, 36.3% and 45%, respectively. There was no statistical difference between the groups for ADH1B and ADH1C (p>0.05). All alcoholic and non-alcoholic subjects (100%) had the allele *1 for ALDH2. The obtained results for ADH1B, ADH1C, and ALDH gene polymorphisms in the present study are similar to the results of Caucasian studies. ADH1B and ADH1C genetic variations are not related to the development of alcoholism or susceptibility to alcoholic cirrhosis. ALDH2 gene has no genetic variation in the Turkish population.

Chronic stress targets posttranscriptional mechanisms to rapidly upregulate α1C-subunit of Cav1.2b calcium channels in colonic smooth muscle cells.

PubMed

Li, Qingjie; Sarna, Sushil K

2011-01-01

Chronic stress elevates plasma norepinephrine, which enhances expression of the α(1C)-subunit of Ca(v)1.2b channels in colonic smooth muscle cells within 1 h. Transcriptional upregulation usually does not explain such rapid protein synthesis. We investigated whether chronic stress-induced release of norepinephrine utilizes posttranscriptional mechanisms to enhance the α(1C)-subunit. We performed experiments on colonic circular smooth muscle strips and in conscious rats, using a 9-day chronic intermittent stress protocol. Incubation of rat colonic muscularis externa with norepinephrine enhanced α(1C)-protein expression within 45 min, without a concomitant increase in α(1C) mRNA, indicating posttranscriptional regulation of α(1C)-protein by norepinephrine. We found that norepinephrine activates the PI3K/Akt/GSK-3β pathway to concurrently enhance α(1C)-protein translation and block its polyubiquitination and proteasomal degradation. Incubation of colonic muscularis externa with norepinephrine or LiCl, which inhibits GSK-3β, enhanced p-GSK-3β and α(1C)-protein time dependently. Using enrichment of phosphoproteins and ubiquitinated proteins, we found that both norepinephrine and LiCl decrease α(1C) phosphorylation and polyubiquitination. Concurrently, they suppress eIF2α (Ser51) phosphorylation and 4E-BP1 expression, which stimulates gene-specific translation. The antagonism of two upstream kinases, PI3K and Akt, inhibits the induction of α(1C)-protein by norepinephrine. Cyanopindolol (β(3)-AR-antagonist) almost completely suppresses and propranolol (β(1/2)-AR antagonist) partially suppresses norepinephrine-induced α(1C)-protein expression, whereas phentolamine and prazosin (α-AR and α(1)-AR antagonist, respectively) have no significant effect. Experiments in conscious animals showed that chronic stress activates the PI3K/Akt/GSK-3β signaling. We conclude that norepinephrine released by chronic stress rapidly enhances the protein expression of α(1C)-subunit of Ca(v)1.2b channels by concurrently suppressing its degradation and enhancing translation of existing transcripts to maintain homeostasis.

APOA1 and APOB polymorphisms and apolipoprotein concentrations as biomarkers of risk in acute coronary syndrome: Relationship with lipid-lowering therapy effectiveness.

PubMed

Casillas-Muñoz, Fidel; Valle, Yeminia; Muñoz-Valle, José Francisco; Martínez-Fernández, Diana Emilia; Reynoso-Villalpando, Gabriela Lizet; Flores-Salinas, Héctor Enrique; Llamas-Covarrubias, Mara Anaís; Padilla-Gutiérrez, Jorge Ramón

2017-10-06

Lipid metabolism alterations contribute to acute coronary syndrome (ACS). rs670, rs5070 and rs693 polymorphisms have shown to modify the risk of cardiovascular disease. Apolipoprotein A-I (ApoA-I) plays a major role in reverse cholesterol transport; apolipoprotein B (ApoB) contributes to accumulation of cholesterol in the plaque. The aim of this study was to investigate the association of rs670 and rs5070 polymorphisms of APOA1 and rs693 polymorphism of APOB with ACS and circulating levels of its proteins and find if ApoB/ApoA-I could be implemented as an independent parameter of risk for cardiovascular disease and as a biomarker of lipid-lowering therapy effectiveness in Mexican population. Three hundred patients with ACS and 300 control subjects (CS) were included. Neither genotype nor allele frequencies of rs670, rs5070 and rs693 polymorphisms showed statistical differences between groups. Serum levels of ApoA-I (195 vs. 161.4mg/dL; P<.001) and ApoB (167 vs. 136.9mg/dL; P<.001) were significantly higher in CS compared with ACS; however, there was no genetic association. Unstable angina patients showed the highest ApoA-I levels (males: 176.3mg/dL; females: 209.1mg/dL). The rs670, rs5070 and rs693 polymorphisms are not genetic susceptibility factors for ACS in Mexican population and had no effect on their apolipoprotein concentrations. In our population, ApoA-I, ApoB and HDL-C could be better biomarkers of cardiovascular risk and could indicate if statins doses reduce atherogenic particles properly. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

Structure-Function, Stability, and Chemical Modification of the Cyanobacterial Cytochrome b6f Complex from Nostoc sp. PCC 7120*

PubMed Central

Baniulis, Danas; Yamashita, Eiki; Whitelegge, Julian P.; Zatsman, Anna I.; Hendrich, Michael P.; Hasan, S. Saif; Ryan, Christopher M.; Cramer, William A.

2009-01-01

The crystal structure of the cyanobacterial cytochrome b6f complex has previously been solved to 3.0-Å resolution using the thermophilic Mastigocladus laminosus whose genome has not been sequenced. Several unicellular cyanobacteria, whose genomes have been sequenced and are tractable for mutagenesis, do not yield b6f complex in an intact dimeric state with significant electron transport activity. The genome of Nostoc sp. PCC 7120 has been sequenced and is closer phylogenetically to M. laminosus than are unicellular cyanobacteria. The amino acid sequences of the large core subunits and four small peripheral subunits of Nostoc are 88 and 80% identical to those in the M. laminosus b6f complex. Purified b6f complex from Nostoc has a stable dimeric structure, eight subunits with masses similar to those of M. laminosus, and comparable electron transport activity. The crystal structure of the native b6f complex, determined to a resolution of 3.0Å (PDB id: 2ZT9), is almost identical to that of M. laminosus. Two unique aspects of the Nostoc complex are: (i) a dominant conformation of heme bp that is rotated 180° about the α- and γ-meso carbon axis relative to the orientation in the M. laminosus complex and (ii) acetylation of the Rieske iron-sulfur protein (PetC) at the N terminus, a post-translational modification unprecedented in cyanobacterial membrane and electron transport proteins, and in polypeptides of cytochrome bc complexes from any source. The high spin electronic character of the unique heme cn is similar to that previously found in the b6f complex from other sources. PMID:19189962

Characteristics of polymorphism at a VNTR locus 3[prime] to the apolipoprotein B gene in five human populations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deka, R.; DeCroo, S.; Ferrell, R.E.

1992-12-01

The authors have analyzed the allele frequency distribution at the hypervariable locus 3[prime] to the apolipoprotein B gene (ApoB 3[prime] VNTR) in five well-defined human populations (Kacharis of northeast India, New Guinea Highlanders of Papua New Guinea, Dogrib Indians of Canada, Pehuenche Indians of Chile, and a relatively homogeneous Caucasian population of northern German extraction) by using the PCR technique. A total of 12 segregating alleles were detected in the pooled sample of 319 individuals. A fairly consistent bimodal pattern of allele frequency distribution, apparent in most of these geographically and genetically diverse populations, suggests that the ApoB 3[prime] VNTRmore » polymorphism predates the geographic dispersal of ancestral human populations. In spite of the observed high degree of polymorphism at this locus (expected heterozygosity levels 55%-78%), the genotype distributions in all populations (irrespective of their tribal or cosmopolitan nature) conform to their respective Hardy-Weinberg predictions. Furthermore, analysis of the congruence between expected heterozygosity and the observed number of alleles reveals that, in general, the allele frequency distributions at this locus are in agreement with the predictions of the classical mutation-drift models. The data also show that alleles that are shared by all populations have the highest average frequency within populations. These findings demonstrate the potential utility of highly informative hypervariable loci such as the ApoB 3[prime] VNTR locus in population genetic research, as well as in forensic medicine and determination of biological relatedness of individuals. 38 refs., 2 figs., 3 tabs.« less

Adaptor protein 1 B mu subunit does not contribute to the recycling of kAE1 protein in polarized renal epithelial cells.

PubMed

Almomani, Ensaf Y; Touret, Nicolas; Cordat, Emmanuelle

2018-04-13

Mutations in the gene encoding the kidney anion exchanger 1 (kAE1) can lead to distal renal tubular acidosis (dRTA). dRTA mutations reported within the carboxyl (C)-terminal tail of kAE1 result in apical mis-targeting of the exchanger in polarized renal epithelial cells. As kAE1 physically interacts with the μ subunit of epithelial adaptor protein 1 B (AP-1B), we investigated the role of heterologously expressed μ1B subunit of the AP-1B complex for kAE1 retention to the basolateral membrane in polarized porcine LLC-PK1 renal epithelial cells that are devoid of endogenous AP-1B. We confirmed the interaction and close proximity between kAE1 and μ1B using immunoprecipitation and proximity ligation assay, respectively. Expressing the human μ1B subunit in these cells decreased significantly the amount of cell surface kAE1 at the steady state, but had no significant effect on kAE1 recycling and endocytosis. We show that (i) heterologous expression of μ1B displaces the physical interaction of endogenous GAPDH with kAE1 WT supporting that both AP-1B and GAPDH proteins bind to an overlapping site on kAE1 and (ii) phosphorylation of tyrosine 904 within the potential YDEV interaction motif does not alter the kAE1/AP-1B interaction. We conclude that μ1B subunit is not involved in recycling of kAE1.

Polymorphism in Alkali Metal Uranyl Nitrates: Synthesis and Crystal Structure of γ-K(UO2)(NO3)3

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jouffret, Laurent J.; Krivovichev, Sergey V.; Burns, Peter C.

2011-07-20

Single crystals of γ-K(UO2)(NO3)3 were prepared from aqueous solutions by evaporation. The crystal structure [orthorhombic, Pbca (61), a = 9.2559(3) Å, b = 12.1753(3) Å, c = 15.8076(5) Å, V = 1781.41(9) Å3, Z = 8] was determined by direct methods and refined to R1 = 0.0267 on the basis of 3657 unique observed reflections. The structure is composed of isolated anionic uranyl trinitrate units, [(UO2)(NO3)3]–, that are linked through eleven-coordinated K+ cations. Both known polymorphs of K(UO2)(NO3)3 (α- and γ-phases) can be considered as based upon sheets of isolated complex [(UO2)(NO3)3]– ions separated by K+ cations. The existence ofmore » polymorphism in the two K[UO2(NO3)3] polymorphs is due to the different packing modes of uranyl trinitrate clusters that adopt the same two-dimensional but different three-dimensional arrangements.« less

X-ray structure, symmetry and mechanism of an AMPA-subtype glutamate receptor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sobolevsky, Alexander I.; Rosconi, Michael P.; Gouaux, Eric

2010-02-02

Ionotropic glutamate receptors mediate most excitatory neurotransmission in the central nervous system and function by opening a transmembrane ion channel upon binding of glutamate. Despite their crucial role in neurobiology, the architecture and atomic structure of an intact ionotropic glutamate receptor are unknown. Here we report the crystal structure of the {alpha}-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA)-sensitive, homotetrameric, rat GluA2 receptor at 3.6 {angstrom} resolution in complex with a competitive antagonist. The receptor harbours an overall axis of two-fold symmetry with the extracellular domains organized as pairs of local dimers and with the ion channel domain exhibiting four-fold symmetry. A symmetry mismatchmore » between the extracellular and ion channel domains is mediated by two pairs of conformationally distinct subunits, A/C and B/D. Therefore, the stereochemical manner in which the A/C subunits are coupled to the ion channel gate is different from the B/D subunits. Guided by the GluA2 structure and site-directed cysteine mutagenesis, we suggest that GluN1 and GluN2A NMDA (N-methyl-D-aspartate) receptors have a similar architecture, with subunits arranged in a 1-2-1-2 pattern. We exploit the GluA2 structure to develop mechanisms of ion channel activation, desensitization and inhibition by non-competitive antagonists and pore blockers.« less

SOFI of GABAB neurotransmitter receptors in hippocampal neurons elucidates intracellular receptor trafficking and assembly

NASA Astrophysics Data System (ADS)

Huss, Anja; Ramírez, Omar; Santibáñez, Felipe; Couve, Andrés.; Härtel, Steffen; Enderlein, Jörg

2013-02-01

The synaptic efficacy of neurons depends on the number of neurotransmitter receptors in the plasma membrane. The availability of these receptors is controlled by their specific intracellular trafficking routes. γ-Aminobutyric acid type B receptors (GABABRs) are heteromeric proteins consisting of GABABR1 and GABABR2 subunits. These receptors are found at the plasma membrane of somatodendritic postsynaptic sites and in axons. It is unknown whether the assembly of the subunits occurs directly in the somatic endoplasmic reticulum (ER) followed by vesicular transport, or whether the assembly occurs after the separate transport of the subunits to the dendritic ER compartment. To address this question we have studied the assembly of the GABABRs in hippocampal neurons with dual-color, 3D super-resolution optical fluctuation imaging (SOFI). SOFI is a fluorescence imaging modality which yields superresolved spatial resolution, 3D-sectioning and high image contrast. We will use the SOFI images to quantify the distribution of the GABABR subunits in the plasma membrane and in the dendritic intracellular compartments. Finally, we want to apply quantitative co-localization analysis to determine the compartments in which the assembly of the GABABR subunits occurs.

Direct evidence that FK506 inhibition of FcepsilonRI-mediated exocytosis from RBL mast cells involves calcineurin.

PubMed

Hultsch, T; Brand, P; Lohmann, S; Saloga, J; Kincaid, R L; Knop, J

1998-05-01

FcepsilonRI-mediated exocytosis of preformed mediators from mast cells and basophils (e.g. histamine, serotonin, beta-hexosaminidase) is sensitive to the immunosuppressants cyclosporin A and FK506 (IC50 200 and 4 nM, respectively) but not rapamycin. The mechanism of inhibition does not appear to involve tyrosine phosphorylation, hydrolysis of inositol phosphates or calcium flux. Here we report experiments using a molecular approach to assess the role of calcineurin, a serine/threonine phosphatase thought to be the primary pharmacological target of these drugs. Calcineurin's activity requires association of its catalytic (A) subunit with an intrinsic regulatory (B) subunit. We hypothesized that calcineurin-sensitive signalling events should be affected by the depletion of calcineurin B subunits, thereby reducing the number of active A:B complexes. We therefore transfected rat basophilic leukemia (RBL) cells with an inhibitory (dominant negative) form of the calcineurin A subunit, which binds the calcineurin B subunit with high affinity but does not possess catalytic activity (B subunit knock-out, BKO). In these transfected cells, the dose-response curve for the inhibition of FcepsilonRI-mediated exocytosis by FK506 was shifted to the left, indicating an increased drug sensitivity of BKO-transfected cells. We conclude that FK506 inhibition of FcepsilonRI-mediated exocytosis in mast cells specifically targets calcineurin activity.

Allelic polymorphism in the T cell receptor and its impact on immune responses.

PubMed

Gras, Stephanie; Chen, Zhenjun; Miles, John J; Liu, Yu Chih; Bell, Melissa J; Sullivan, Lucy C; Kjer-Nielsen, Lars; Brennan, Rebekah M; Burrows, Jacqueline M; Neller, Michelle A; Khanna, Rajiv; Purcell, Anthony W; Brooks, Andrew G; McCluskey, James; Rossjohn, Jamie; Burrows, Scott R

2010-07-05

In comparison to human leukocyte antigen (HLA) polymorphism, the impact of allelic sequence variation within T cell receptor (TCR) loci is much less understood. Particular TCR loci have been associated with autoimmunity, but the molecular basis for this phenomenon is undefined. We examined the T cell response to an HLA-B*3501-restricted epitope (HPVGEADYFEY) from Epstein-Barr virus (EBV), which is frequently dominated by a TRBV9*01(+) public TCR (TK3). However, the common allelic variant TRBV9*02, which differs by a single amino acid near the CDR2beta loop (Gln55-->His55), was never used in this response. The structure of the TK3 TCR, its allelic variant, and a nonnaturally occurring mutant (Gln55-->Ala55) in complex with HLA-B*3501(HPVGEADYFEY) revealed that the Gln55-->His55 polymorphism affected the charge complementarity at the TCR-peptide-MHC interface, resulting in reduced functional recognition of the cognate and naturally occurring variants of this EBV peptide. Thus, polymorphism in the TCR loci may contribute toward variability in immune responses and the outcome of infection.

Smoking and polymorphisms of fucosyltransferase gene Le affect success of H. pylori eradication with lansoprazole, amoxicillin, and clarithromycin.

PubMed Central

Matsuo, K.; Hamajima, N.; Ikehara, Y.; Suzuki, T.; Nakamura, T.; Matsuura, A.; Tajima, K.; Tominaga, S.

2003-01-01

Identification of factors influencing success of Helicobacter pylori (HP) eradication is important for clinical practice. We have prospectively conducted an HP eradication study in the Aichi Cancer Center with a total of 142 patients available for analysis. The overall success rate was 61.3% (95% confidence interval 52.7-69.3%). Smoking during the medication for eradication significantly decreased the success rate (42.9%), whereas smoking cessation during the treatment was associated with a similar rate as for non-smokers (66.7%). We also examined links between an eradication outcome and polymorphisms of Le, Se, IL1A, IL1B, IL1RN and MPO genes, but with one exception none showed any association. The non-functional le allele of Le polymorphisms, leading to decreased expression of Le(b) antigen to which HP attaches with adhesin, showed a beneficial effect for success. Although further clarification is necessary, our study indicated that smoking cessation and Le gene polymorphisms may affect the success rate of HP eradication. PMID:12729191

Status Epilepticus Impairs Synaptic Plasticity in Rat Hippocampus and Is Followed by Changes in Expression of NMDA Receptors.

PubMed

Postnikova, T Y; Zubareva, O E; Kovalenko, A A; Kim, K K; Magazanik, L G; Zaitsev, A V

2017-03-01

Cognitive deficits and memory loss are frequent in patients with temporal lobe epilepsy. Persistent changes in synaptic efficacy are considered as a cellular substrate underlying memory processes. Electrophysiological studies have shown that the properties of short-term and long-term synaptic plasticity in the cortex and hippocampus may undergo substantial changes after seizures. However, the neural mechanisms responsible for these changes are not clear. In this study, we investigated the properties of short-term and long-term synaptic plasticity in rat hippocampal slices 24 h after pentylenetetrazole (PTZ)-induced status epilepticus. We found that the induction of long-term potentiation (LTP) in CA1 pyramidal cells is reduced compared to the control, while short-term facilitation is increased. The experimental results do not support the hypothesis that status epilepticus leads to background potentiation of hippocampal synapses and further LTP induction becomes weaker due to occlusion, as the dependence of synaptic responses on the strength of input stimulation was not different in the control and experimental animals. The decrease in LTP can be caused by impairment of molecular mechanisms of neuronal plasticity, including those associated with NMDA receptors and/or changes in their subunit composition. Real-time PCR demonstrated significant increases in the expression of GluN1 and GluN2A subunits 3 h after PTZ-induced status epilepticus. The overexpression of obligate GluN1 subunit suggests an increase in the total number of NMDA receptors in the hippocampus. A 3-fold increase in the expression of the GluN2B subunit observed 24 h after PTZ-induced status epilepticus might be indicative of an increase in the proportion of GluN2B-containing NMDA receptors. Increased expression of the GluN2B subunit may be a cause for reducing the magnitude of LTP at hippocampal synapses after status epilepticus.

Protein Interactions and Localization of the Escherichia coli Accessory Protein HypA during Nickel Insertion to [NiFe] Hydrogenase*

PubMed Central

Chan Chung, Kim C.; Zamble, Deborah B.

2011-01-01

Nickel delivery during maturation of Escherichia coli [NiFe] hydrogenase 3 includes the accessory proteins HypA, HypB, and SlyD. Although the isolated proteins have been characterized, little is known about how they interact with each other and the hydrogenase 3 large subunit, HycE. In this study the complexes of HypA and HycE were investigated after modification with the Strep-tag II. Multiprotein complexes containing HypA, HypB, SlyD, and HycE were observed, consistent with the assembly of a single nickel insertion cluster. An interaction between HypA and HycE did not require the other nickel insertion proteins, but HypB was not found with the large subunit in the absence of HypA. The HypA-HycE complex was not detected in the absence of the HypC or HypD proteins, involved in the preceding iron insertion step, and this interaction is enhanced by nickel brought into the cell by the NikABCDE membrane transporter. Furthermore, without the hydrogenase 1, 2, and 3 large subunits, complexes between HypA, HypB, and SlyD were observed. These results support the hypothesis that HypA acts as a scaffold for assembly of the nickel insertion proteins with the hydrogenase precursor protein after delivery of the iron center. At different stages of the hydrogenase maturation process, HypA was observed at or near the cell membrane by using fluorescence confocal microscopy, as was HycE, suggesting membrane localization of the nickel insertion event. PMID:22016389

Biogenesis of the bacterial cbb3 cytochrome c oxidase: Active subcomplexes support a sequential assembly model.

PubMed

Durand, Anne; Bourbon, Marie-Line; Steunou, Anne-Soisig; Khalfaoui-Hassani, Bahia; Legrand, Camille; Guitton, Audrey; Astier, Chantal; Ouchane, Soufian

2018-01-19

The cbb 3 oxidase has a high affinity for oxygen and is required for growth of bacteria, including pathogens, in oxygen-limited environments. However, the assembly of this oxidase is poorly understood. Most cbb 3 are composed of four subunits: the catalytic CcoN subunit, the two cytochrome c subunits (CcoO and CcoP) involved in electron transfer, and the small CcoQ subunit with an unclear function. Here, we address the role of these four subunits in cbb 3 biogenesis in the purple bacterium Rubrivivax gelatinosus Analyses of membrane proteins from different mutants revealed the presence of active CcoNQO and CcoNO subcomplexes and also showed that the CcoP subunit is not essential for their assembly. However, CcoP was required for the oxygen reduction activity in the absence of CcoQ. We also found that CcoQ is dispensable for forming an active CcoNOP subcomplex in membranes. CcoNOP exhibited oxygen reductase activity, indicating that the cofactors (hemes b and copper for CcoN and cytochromes c for CcoO and CcoP) were present within the subunits. Finally, we discovered the presence of a CcoNQ subcomplex and showed that CcoN is the required anchor for the assembly of the full CcoNQOP complex. On the basis of these findings, we propose a sequential assembly model in which the CcoQ subunit is required for the early maturation step: CcoQ first associates with CcoN before the CcoNQ-CcoO interaction. CcoP associates to CcoNQO subcomplex in the late maturation step, and once the CcoNQOP complex is fully formed, CcoQ is released for degradation by the FtsH protease. This model could be conserved in other bacteria, including the pathogenic bacteria lacking the assembly factor CcoH as in R. gelatinosus . © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

Radiological sacroiliitis, a hallmark of spondylitis, is linked with CARD15 gene polymorphisms in patients with Crohn's disease

PubMed Central

Peeters, H; Vander, C; Laukens, D; Coucke, P; Marichal, D; Van Den Berghe, M; Cuvelier, C; Remaut, E; Mielants, H; De Keyser, F; Vos, M

2004-01-01

Background: Sacroiliitis is a common extraintestinal manifestation of Crohn's disease but its association with the HLA-B27 phenotype is less evident. Polymorphisms in the CARD15 gene have been linked to higher susceptibility for Crohn's disease. In particular, associations have been found with ileal and fibrostenosing disease, young age at onset of disease, and familial cases. Objectives: To investigate whether the presence of sacroiliitis in patients with Crohn's disease is linked to the carriage of CARD15 polymorphisms. Methods: 102 consecutive patients with Crohn's disease were clinically evaluated by a rheumatologist. Radiographs of the sacroiliac joints were taken and assessed blindly by two investigators. The RFLP-PCR technique was used to genotype all patients for three single nucleotide polymorphisms (SNP) in the CARD15 gene. Every SNP was verified by direct sequencing. The HLA-B27 phenotype was determined. Results: Radiological evidence of sacroiliitis with or without ankylosing spondylitis was found in 23 patients (23%), of whom only three were HLA-B27 positive. In contrast, 78% of patients with sacroiliitis carried a CARD15 variant v 48% of those without sacroiliitis (p = 0.01; odds ratio 3.8 (95% confidence interval, 1.3 to 11.5)). Multivariate analysis (logistic regression) showed that the association between sacroiliitis and CARD15 polymorphisms was independent of other CARD15 related phenotypes (ileal and fibrostenosing disease, young age at onset of disease, familial Crohn's disease) (p = 0.039). Conclusions: CARD15 variants were identified as genetic predictors of Crohn's disease related sacroiliitis. An association was demonstrated between these polymorphisms and an extraintestinal manifestation of Crohn's disease. PMID:15308523

Sequence and functional characterization of hypoxia-inducible factors, HIF1α, HIF2αa, and HIF3α, from the estuarine fish, Fundulus heteroclitus

PubMed Central

Townley, Ian K.; Karchner, Sibel I.; Skripnikova, Elena; Wiese, Thomas E.; Hahn, Mark E.

2017-01-01

The hypoxia-inducible factor (HIF) family of transcription factors plays central roles in the development, physiology, pathology, and environmental adaptation of animals. Because many aquatic habitats are characterized by episodes of low dissolved oxygen, fish represent ideal models to study the roles of HIF in the response to aquatic hypoxia. The estuarine fish Fundulus heteroclitus is found in habitats prone to hypoxia. It responds to low oxygen via behavioral, physiological, and molecular changes, and one member of the HIF family, HIF2α, has been previously described. Herein, cDNA sequencing, phylogenetic analyses, and genomic approaches were used to determine other members of the HIFα family from F. heteroclitus and their relationships to HIFα subunits from other vertebrates. In vitro and cellular approaches demonstrated that full-length forms of HIF1α, HIF2α, and HIF3α independently formed complexes with the β-subunit, aryl hydrocarbon receptor nuclear translocator, to bind to hypoxia response elements and activate reporter gene expression. Quantitative PCR showed that HIFα mRNA abundance varied among organs of normoxic fish in an isoform-specific fashion. Analysis of the F. heteroclitus genome revealed a locus encoding a second HIF2α—HIF2αb—a predicted protein lacking oxygen sensing and transactivation domains. Finally, sequence analyses demonstrated polymorphism in the coding sequence of each F. heteroclitus HIFα subunit, suggesting that genetic variation in these transcription factors may play a role in the variation in hypoxia responses among individuals or populations. PMID:28039194

Interaction between Serotonin Transporter and Serotonin Receptor 1 B genes polymorphisms may be associated with antisocial alcoholism

PubMed Central

2012-01-01

Background Several studies have hypothesized that genes regulating the components of the serotonin system, including serotonin transporter (5-HTTLPR) and serotonin 1 B receptor (5-HT1B), may be associated with alcoholism, but their results are contradictory because of alcoholism’s heterogeneity. Therefore, we examined whether the 5-HTTLPR gene and 5-HT1B gene G861C polymorphism are susceptibility factors for a specific subtype of alcoholism, antisocial alcoholism in Han Chinese in Taiwan. Methods We recruited 273 Han Chinese male inmates with antisocial personality disorder (ASPD) [antisocial alcoholism (AS-ALC) group (n = 120) and antisocial non-alcoholism (AS-N-ALC) group (n = 153)] and 191 healthy male controls from the community. Genotyping was done using PCR-RFLP. Results There were no significant differences in the genotypic frequency of the 5-HT1B G861C polymorphism between the 3 groups. Although AS-ALC group members more frequently carried the 5-HTTLPR S/S, S/LG, and LG/LG genotypes than controls, the difference became non-significant after controlling for the covarying effects of age. However, the 5-HTTLPR S/S, S/LG, and LG/LG genotypes may have interacted with the 5-HT1B G861C C/C polymorphism and increased the risk of becoming antisocial alcoholism. Conclusion Our study suggests that neither the 5-HTTLPR gene nor the 5-HT1B G861C polymorphism alone is a risk factor for antisocial alcoholism in Taiwan’s Han Chinese population, but that the interaction between both genes may increase susceptibility to antisocial alcoholism. PMID:22550993

Genetic polymorphisms of PPAR gamma, arsenic methylation capacity and breast cancer risk in Mexican women.

PubMed

Pineda-Belmontes, Cristina P; Hernández-Ramírez, Raúl U; Hernández-Alcaraz, César; Cebrián, Mariano E; López-Carrillo, Lizbeth

2016-04-01

To evaluate whether the presence of polymorphisms of peroxisome proliferator-activated receptor gamma PPARγ (Pro 1 2Ala) and PPARGC1B (Ala203Pro) modifies the association between the inorganic arsenic (iAs) methylation capacity and breast cancer (BC). Mexican women were interviewed, and blood and urine samples were collected from them (cases/controls= 197/220). The concentration of urinary arsenic species and the polymorphisms of interest were determined by high-performance liquid chromatography with inductively coupled plasma mass spectrometry (HPLC-ICP-MS) and polymerase chain reaction (PCR), respectively. In women with a high %MMA (urinary monomethyl arsenic) and high primary methylation ratio (PM = MMA/iAs), the risk of BC was increased (odds ratio [OR]%MMA T3 vs.T1= 3.60: 95% confidence interval [CI] 2.02-6.41, ORPMI T3 vs.T1= 3.47: 95%CI 1.95-6.17), which was maintained after adjusting for polymorphisms. No significant interactions were observed between the polymorphisms and the arsenic variables on the risk of BC. Pro 12Ala and Ala203Pro polymorphisms did not modify the association between the iAs methylation capacity and BC.

Genetic polymorphisms in glutathione (GSH-) related genes affect the plasmatic Hg/whole blood Hg partitioning and the distribution between inorganic and methylmercury levels in plasma collected from a fish-eating population.

PubMed

de Oliveira, Andréia Ávila Soares; de Souza, Marilesia Ferreira; Lengert, André van Helvoort; de Oliveira, Marcelo Tempesta; Camargo, Rossana Batista de Oliveira Godoy; Braga, Gilberto Úbida Leite; Cólus, Ilce Mara de Syllos; Barbosa, Fernando; Barcelos, Gustavo Rafael Mazzaron

2014-01-01

This study aims to evaluate the effects of polymorphisms in glutathione (GSH-) related genes (GSTM1, GSTT1, GSTP1, GCLM, and GCLC) in the distribution of Hg in the blood compartments in humans exposed to methylmercury (MeHg). Subjects (n = 88), exposed to MeHg from fish consumption, were enrolled in the study. Hg species in the plasma compartment were determined by LC-ICP-MS, whereas genotyping was performed by PCR assays. Mean total Hg levels in plasma (THgP) and whole blood (THgB) were 10 ± 4.2 and 37 ± 21, whereas mean levels of plasmatic MeHg (MeHgP), inorganic Hg (IHgP), and HgP/HgB were 4.3 ± 2.9, 5.8 ± 2.3 µg/L, and 0.33 ± 0.15, respectively. GSTM1 and GCLC polymorphisms influence THgP and MeHgP (multivariate analyses, P < 0.050). Null homozygotes for GSTM1 showed higher THgP and MeHgP levels compared to subjects with GSTM1 (THgP β = 0.22, P = 0.035; MeHgP β = 0.30, P = 0.050) and persons carrying at least one T allele for GCLC had significant higher MeHgP (β = 0.59, P = 0.046). Also, polymorphic GCLM subjects had lower THgP/THgB than those with the nonvariant genotype. Taken together, data of this study suggest that GSH-related polymorphisms may change the metabolism of MeHg by modifying the distribution of mercury species iin plasma compartment and the HgP/HgB partitioning.

Genetic Polymorphisms in Glutathione (GSH-) Related Genes Affect the Plasmatic Hg/Whole Blood Hg Partitioning and the Distribution between Inorganic and Methylmercury Levels in Plasma Collected from a Fish-Eating Population

PubMed Central

de Oliveira, Andréia Ávila Soares; de Souza, Marilesia Ferreira; Lengert, André van Helvoort; de Oliveira, Marcelo Tempesta; Camargo, Rossana Batista de Oliveira Godoy; Braga, Gilberto Úbida Leite; Cólus, Ilce Mara de Syllos; Barbosa, Fernando; Barcelos, Gustavo Rafael Mazzaron

2014-01-01

This study aims to evaluate the effects of polymorphisms in glutathione (GSH-) related genes (GSTM1, GSTT1, GSTP1, GCLM, and GCLC) in the distribution of Hg in the blood compartments in humans exposed to methylmercury (MeHg). Subjects (n = 88), exposed to MeHg from fish consumption, were enrolled in the study. Hg species in the plasma compartment were determined by LC-ICP-MS, whereas genotyping was performed by PCR assays. Mean total Hg levels in plasma (THgP) and whole blood (THgB) were 10 ± 4.2 and 37 ± 21, whereas mean evels of plasmatic MeHg (MeHgP), inorganic Hg (IHgP), and HgP/HgB were 4.3 ± 2.9, 5.8 ± 2.3 µg/L, and 0.33 ± 0.15, respectively. GSTM1 and GCLC polymorphisms influence THgP and MeHgP (multivariate analyses, P < 0.050). Null homozygotes for GSTM1 showed higher THgP and MeHgP levels compared to subjects with GSTM1 (THgP β = 0.22, P = 0.035; MeHgP β = 0.30, P = 0.050) and persons carrying at least one T allele for GCLC had significant higher MeHgP (β = 0.59, P = 0.046). Also, polymorphic GCLM subjects had lower THgP/THgB than those with the nonvariant genotype. Taken together, data of this study suggest that GSH-related polymorphisms may change the metabolism of MeHg by modifying the distribution of mercury species iin plasma compartment and the HgP/HgB partitioning. PMID:24696865

Localization and Function of the Membrane-bound Riboflavin in the Na+-translocating NADH:Quinone Oxidoreductase (Na+-NQR) from Vibrio cholerae*

PubMed Central

Casutt, Marco S.; Huber, Tamara; Brunisholz, René; Tao, Minli; Fritz, Günter; Steuber, Julia

2010-01-01

The sodium ion-translocating NADH:quinone oxidoreductase (Na+-NQR) from the human pathogen Vibrio cholerae is a respiratory membrane protein complex that couples the oxidation of NADH to the transport of Na+ across the bacterial membrane. The Na+-NQR comprises the six subunits NqrABCDEF, but the stoichiometry and arrangement of these subunits are unknown. Redox-active cofactors are FAD and a 2Fe-2S cluster on NqrF, covalently attached FMNs on NqrB and NqrC, and riboflavin and ubiquinone-8 with unknown localization in the complex. By analyzing the cofactor content and NADH oxidation activity of subcomplexes of the Na+-NQR lacking individual subunits, the riboflavin cofactor was unequivocally assigned to the membrane-bound NqrB subunit. Quantitative analysis of the N-terminal amino acids of the holo-complex revealed that NqrB is present in a single copy in the holo-complex. It is concluded that the hydrophobic NqrB harbors one riboflavin in addition to its covalently attached FMN. The catalytic role of two flavins in subunit NqrB during the reduction of ubiquinone to ubiquinol by the Na+-NQR is discussed. PMID:20558724

A potential link between insulin signaling and GLUT4 translocation: Association of Rab10-GTP with the exocyst subunit Exoc6/6b

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sano, Hiroyuki; Peck, Grantley R.; Blachon, Stephanie

Insulin increases glucose transport in fat and muscle cells by stimulating the exocytosis of specialized vesicles containing the glucose transporter GLUT4. This process, which is referred to as GLUT4 translocation, increases the amount of GLUT4 at the cell surface. Previous studies have provided evidence that insulin signaling increases the amount of Rab10-GTP in the GLUT4 vesicles and that GLUT4 translocation requires the exocyst, a complex that functions in the tethering of vesicles to the plasma membrane, leading to exocytosis. In the present study we show that Rab10 in its GTP form binds to Exoc6 and Exoc6b, which are the twomore » highly homologous isotypes of an exocyst subunit, that both isotypes are found in 3T3-L1 adipocytes, and that knockdown of Exoc6, Exoc6b, or both inhibits GLUT4 translocation in 3T3-L1 adipocytes. These results suggest that the association of Rab10-GTP with Exoc6/6b is a molecular link between insulin signaling and the exocytic machinery in GLUT4 translocation. - Highlights: • Insulin stimulates the fusion of vesicles containing GLUT4 with the plasma membrane. • This requires vesicular Rab10-GTP and the exocyst plasma membrane tethering complex. • We find that Rab10-GTP associates with the Exoc6 subunit of the exocyst. • We find that knockdown of Exoc6 inhibits fusion of GLUT4 vesicles with the membrane. • The interaction of Rab10-GTP with Exoc6 potentially links signaling to exocytosis.« less

The B55α Regulatory Subunit of Protein Phosphatase 2A Mediates Fibroblast Growth Factor-Induced p107 Dephosphorylation and Growth Arrest in Chondrocytes

PubMed Central

Daempfling, Lea

2013-01-01

Fibroblast growth factor (FGF)-induced growth arrest of chondrocytes is a unique cell type-specific response which contrasts with the proliferative response of most cell types and underlies several genetic skeletal disorders caused by activating FGF receptor (FGFR) mutations. We have shown that one of the earliest key events in FGF-induced growth arrest is dephosphorylation of the retinoblastoma protein (Rb) family member p107 by protein phosphatase 2A (PP2A), a ubiquitously expressed multisubunit phosphatase. In this report, we show that the PP2A-B55α holoenzyme (PP2A containing the B55α subunit) is responsible for this phenomenon. Only the B55α (55-kDa regulatory subunit, alpha isoform) regulatory subunit of PP2A was able to bind p107, and this interaction was induced by FGF in chondrocytes but not in other cell types. Small interfering RNA (siRNA)-mediated knockdown of B55α prevented p107 dephosphorylation and FGF-induced growth arrest of RCS (rat chondrosarcoma) chondrocytes. Importantly, the B55α subunit bound with higher affinity to dephosphorylated p107. Since the p107 region interacting with B55α is also the site of cyclin-dependent kinase (CDK) binding, B55α association may also prevent p107 phosphorylation by CDKs. FGF treatment induces dephosphorylation of the B55α subunit itself on several serine residues that drastically increases the affinity of B55α for the PP2A A/C dimer and p107. Together these observations suggest a novel mechanism of p107 dephosphorylation mediated by activation of PP2A through B55α dephosphorylation. This mechanism might be a general signal transduction pathway used by PP2A to initiate cell cycle arrest when required by external signals. PMID:23716589

Expression of cholera toxin B subunit in transgenic tomato plants.

PubMed

Jani, Dewal; Meena, Laxman Singh; Rizwan-ul-Haq, Quazi Mohammad; Singh, Yogendra; Sharma, Arun K; Tyagi, Akhilesh K

2002-10-01

Cholera toxin, secreted by Vibrio cholerae, consists of A and B subunits. The latter binds to G(M1)-ganglioside receptors as a pentamer (approximately 55 kDa). Tomato plants were transformed with the gene encoding cholera toxin B subunit (ctxB) along with an endoplasmic reticulum retention signal (SEKDEL) under the control of the CaMV 35S promoter via Agrobacterium-mediated transformation. PCR and Southern analysis confirmed the presence of the ctxB gene in transformed tomato plants. Northern analysis showed the presence of the ctxB-specific transcript. Immunoblot assays of the plant-derived protein extract showed the presence of cholera toxin subunit B (CTB) with mobility similar to purified CTB from V. cholerae. Both tomato leaves and fruits expressed CTB at levels up to 0.02 and 0.04% of total soluble protein, respectively. The G(M1)-ELISA showed that the plant-derived CTB bound specifically to G(M1)-ganglioside receptor, suggesting that it retained its native pentameric form. This study forms a basis for exploring the utility of CTB to develop tomato-based edible vaccines against cholera.

The structure of the protein phosphatase 2A PR65/A subunit reveals the conformation of its 15 tandemly repeated HEAT motifs.

PubMed

Groves, M R; Hanlon, N; Turowski, P; Hemmings, B A; Barford, D

1999-01-08

The PR65/A subunit of protein phosphatase 2A serves as a scaffolding molecule to coordinate the assembly of the catalytic subunit and a variable regulatory B subunit, generating functionally diverse heterotrimers. Mutations of the beta isoform of PR65 are associated with lung and colon tumors. The crystal structure of the PR65/Aalpha subunit, at 2.3 A resolution, reveals the conformation of its 15 tandemly repeated HEAT sequences, degenerate motifs of approximately 39 amino acids present in a variety of proteins, including huntingtin and importin beta. Individual motifs are composed of a pair of antiparallel alpha helices that assemble in a mainly linear, repetitive fashion to form an elongated molecule characterized by a double layer of alpha helices. Left-handed rotations at three interrepeat interfaces generate a novel left-hand superhelical conformation. The protein interaction interface is formed from the intrarepeat turns that are aligned to form a continuous ridge.

SLCO2B1 and SLCO1B3 May Determine Time to Progression for Patients Receiving Androgen Deprivation Therapy for Prostate Cancer

PubMed Central

Yang, Ming; Xie, Wanling; Mostaghel, Elahe; Nakabayashi, Mari; Werner, Lillian; Sun, Tong; Pomerantz, Mark; Freedman, Matthew; Ross, Robert; Regan, Meredith; Sharifi, Nima; Figg, William Douglas; Balk, Steven; Brown, Myles; Taplin, Mary-Ellen; Oh, William K.; Lee, Gwo-Shu Mary; Kantoff, Philip W.

2011-01-01

Purpose Androgen deprivation therapy (ADT), an important treatment for advanced prostate cancer, is highly variable in its effectiveness. We hypothesized that genetic variants of androgen transporter genes, SLCO2B1 and SLCO1B3, may determine time to progression on ADT. Patients and Methods A cohort of 538 patients with prostate cancer treated with ADT was genotyped for SLCO2B1 and SLCO1B3 single nucleotide polymorphisms (SNP). The biologic function of a SLCO2B1 coding SNP in transporting androgen was examined through biochemical assays. Results Three SNPs in SLCO2B1 were associated with time to progression (TTP) on ADT (P < .05). The differences in median TTP for each of these polymorphisms were about 10 months. The SLCO2B1 genotype, which allows more efficient import of androgen, enhances cell growth and is associated with a shorter TTP on ADT. Patients carrying both SLCO2B1 and SLCO1B3 genotypes, which import androgens more efficiently, exhibited a median 2-year shorter TTP on ADT, demonstrating a gene-gene interaction (Pinteraction = .041). Conclusion Genetic variants of SLCO2B1 and SLCO1B3 may function as pharmacogenomic determinants of resistance to ADT in prostate cancer. PMID:21606417

Polymorphism in Bi2(SO4)3

NASA Astrophysics Data System (ADS)

Subban, Chinmayee V.; Rousse, Gwenaëlle; Courty, Matthieu; Barboux, Philippe; Tarascon, Jean-Marie

2014-12-01

A new polymorph of Bi2(SO4)3 was prepared by reaction of LiBiO2 with H2SO4 and its crystal structure was solved from X-ray powder diffraction. This new polymorph crystallizes in C2/c space group with lattice parameters a = 17.3383(3) Å, b = 6.77803(12) Å, c = 8.30978(13) Å, β = 101.4300(12)°. Bi2(SO4)3 presents a layered structure made of SO4 sulfate groups and signs of stereochemically active Bi3+ lone pairs. The new Bi2(SO4)3 absorbs water to form Bi2(H2O)2(SO4)2(OH)2 through an intermediate Bi2O(OH)2SO4 phase, and the transition is reversible when heated under vacuum.

Systematic screening for CYP3A4 genetic polymorphisms in a Han Chinese population.

PubMed

Hu, Guo-Xin; Dai, Da-Peng; Wang, Hao; Huang, Xiang-Xin; Zhou, Xiao-Yang; Cai, Jie; Chen, Hao; Cai, Jian-Ping

2017-03-01

To systematically investigate the genetic polymorphisms of the CYP3A4 gene in a Han Chinese population. The promoter and exons of CYP3A4 gene in 1114 unrelated, healthy Han Chinese subjects were amplified and genotyped by direct sequencing. In total, five previously reported alleles (*1G, *4, *5, *18B and *23) were detected, of which one allele (*23) was reported for the first time in Han Chinese population. Additionally, seven novel exonic variants were also identified and designated as new alleles CYP3A4*28-*34. This study provides the most comprehensive data of CYP3A4 polymorphisms in Han Chinese population and detects the largest number of novel CYP3A4 alleles in one ethnic group.

Identification of Species and Sources of Cryptosporidium Oocysts in Storm Waters with a Small-Subunit rRNA-Based Diagnostic and Genotyping Tool

PubMed Central

Xiao, Lihua; Alderisio, Kerri; Limor, Josef; Royer, Michael; Lal, Altaf A.

2000-01-01

The identification of Cryptosporidium oocysts in environmental samples is largely made by the use of an immunofluorescent assay. In this study, we have used a small-subunit rRNA-based PCR-restriction fragment length polymorphism technique to identify species and sources of Cryptosporidium oocysts present in 29 storm water samples collected from a stream in New York. A total of 12 genotypes were found in 27 positive samples; for 4 the species and probable origins were identified by sequence analysis, whereas the rest represent new genotypes from wildlife. Thus, this technique provides an alternative method for the detection and differentiation of Cryptosporidium parasites in environmental samples. PMID:11097935

Fission yeast translation initiation factor 3 subunit eIF3h is not essential for global translation initiation, but deletion of eif3h+ affects spore formation.

PubMed

Ray, Anirban; Bandyopadhyay, Amitabha; Matsumoto, Tomohiro; Deng, Haiteng; Maitra, Umadas

2008-11-01

The fission yeast Schizosaccharomyces pombe homologue of the p40/eIF3h subunit of mammalian translation initiation factor eIF3 has been characterized in this study. We show that this protein physically associates with the 40S ribosomal particles as a constituent of the multimeric eIF3 protein complex, which consists of all five known eIF3 core subunits (eIF3a, eIF3b, eIF3c, eIF3g and eIF3i) as well as the five non-core subunits (eIF3d, eIF3e, eIF3f, eIF3h and eIF3m) that constitute an eIF3 holocomplex in fission yeast. However, affinity purification of eIF3 from fission yeast cells expressing TAP-tagged eIF3h suggests the presence of distinct forms of eIF3 that differ in their composition of the non-core subunits. Further characterization of eIF3h shows that strains lacking eif3h(+) (eif3hDelta) are viable and show no gross defects, either in vegetative growth or in the rate of in vivo protein synthesis. Polysome profile analysis shows no apparent defects in translation initiation. Furthermore, deletion of eif3h(+) does not affect the ability of the other eIF3 subunits to remain associated with one another in a tight protein complex similar to the situation in wild-type cells. Additionally, we show that human eIF3h can functionally substitute fission yeast eIF3h in complementing in vivo a genetic deletion of eif3h(+). Interestingly, mutant eif3hDelta cells show several prominent phenotypic properties. They are hypersensitive to caffeine and highly defective in meiosis, producing either no spores or incomplete tetrads with a very high frequency. The implications of these results in relation to the functions of eIF3h in Sz. pombe are discussed. (c) 2008 John Wiley & Sons, Ltd.

PIK3CA rs7640662 (C/G) single nucleotide polymorphism lacks association with breast cancer cases in Persians

PubMed Central

Mir, Atefeh; Sadegh, Mahdiyeh Harati; Ahmadinia, Zahra

2015-01-01

Phosphatidylinositol-3-kinase (PI3K) is a group of enzymes involved in cellular growth, proliferation, differentiation, cell motility, intracellular trafficking, and survival that play very important roles in developing breast cancer. PIK3CA is a gene that encodes α catalytic subunit of this enzyme. A common polymorphism of PIK3CA, rs7640662 (C/G), was analyzed, and its association to breast cancer cases was determined. In this study, DNA was extracted from peripheral blood samples of 278 women suffering from breast cancer and 128 healthy women. Tetra-primer amplification refractory mutation system polymerase chain reaction (T-ARMS-PCR) method was performed to genotype rs7640662. P values and ODD ratios were measured using SPSS. P value less than 0.05 and ODD ratios more than 1 were considered as significant. All ODD ratios were less than 1, and P values were more than 0.05 showing that rs7640662 (C/G) and breast cancer are not significantly associated. However, the genotypes observed in the Persian population, as an ancient population living in the Middle East, was significantly different from the genotypes reported by HapMap for Asian populations. As a conclusion, rs7640662 was not associated with the risk of breast cancer in a Persian population; however, it was observed that heterozygote (GC) is the most common genotypes in both case and control samples. PMID:25838920

Propofol effectively inhibits lithium-pilocarpine- induced status epilepticus in rats via downregulation of N-methyl-D-aspartate receptor 2B subunit expression

PubMed Central

Wang, Henglin; Wang, Zhuoqiang; Mi, Weidong; Zhao, Cong; Liu, Yanqin; Wang, Yongan; Sun, Haipeng

2012-01-01

Status epilepticus was induced via intraperitoneal injection of lithium-pilocarpine. The inhibitory effects of propofol on status epilepticus in rats were judged based on observation of behavior, electroencephalography and 24-hour survival rate. Propofol (12.5–100 mg/kg) improved status epilepticus in a dose-dependent manner, and significantly reduced the number of deaths within 24 hours of lithium-pilocarpine injection. Western blot results showed that, 24 hours after induction of status epilepticus, the levels of N-methyl-D-aspartate receptor 2A and 2B subunits were significantly increased in rat cerebral cortex and hippocampus. Propofol at 50 mg/kg significantly suppressed the increase in N-methyl-D-aspartate receptor 2B subunit levels, but not the increase in N-methyl-D-aspartate receptor 2A subunit levels. The results suggest that propofol can effectively inhibit status epilepticus induced by lithium-pilocarpine. This effect may be associated with downregulation of N-methyl-D-aspartate receptor 2B subunit expression after seizures. PMID:25737709

Crystal structure of a two-subunit TrkA octameric gating ring assembly

DOE PAGES

Deller, Marc C.; Johnson, Hope A.; Miller, Mitchell D.; ...

2015-03-31

The TM1088 locus of T. maritima codes for two proteins designated TM1088A and TM1088B, which combine to form the cytosolic portion of a putative Trk K⁺ transporter. We report the crystal structure of this assembly to a resolution of 3.45 Å. The high resolution crystal structures of the components of the assembly, TM1088A and TM1088B, were also determined independently to 1.50 Å and 1.55 Å, respectively. The TM1088 proteins are structurally homologous to each other and to other K⁺ transporter proteins, such as TrkA. These proteins form a cytosolic gating ring assembly that controls the flow of K⁺ ions acrossmore » the membrane. TM1088 represents the first structure of a two-subunit Trk assembly. Despite the atypical genetics and chain organization of the TM1088 assembly, it shares significant structural homology and an overall quaternary organization with other single-subunit K⁺ gating ring assemblies. This structure provides the first structural insights into what may be an evolutionary ancestor of more modern single-subunit K⁺ gating ring assemblies.« less

Monoclinic structures of niobium trisulfide

NASA Astrophysics Data System (ADS)

Bloodgood, Matthew A.; Wei, Pingrong; Aytan, Ece; Bozhilov, Krassimir N.; Balandin, Alexander A.; Salguero, Tina T.

2018-02-01

Two new polymorphs of niobium trisulfide are established by single crystal x-ray diffraction. NbS3-iv crystallizes in the monoclinic space group P21/c with lattice parameters a = 6.7515(5) Å, b = 4.9736(4) Å, c = 18.1315(13) Å, and β = 90.116(2)°. Its structure is based on chains of [NbS6] trigonal prisms containing Nb-Nb pairs with a bond length of 3.0448(8) Å; this pairing causes the chains to corrugate slightly along their axis, a feature also present in triclinic NbS3-i that leads to semiconductor properties. The stacking arrangement of chains is different in these polymorphs, however, with NbS3-i having an ABCDE repeating sequence of chain bilayers and NbS3-iv having an AB repeating sequence. HRTEM studies show the presence of topotactically-oriented intergrown zones and numerous dislocations, which result in mosaic structuring. A second new polymorph, NbS3-v, crystallizes in the monoclinic space group P21/m with lattice parameters a = 4.950(5) Å, b = 3.358(4) Å, c = 9.079(10) Å, β = 97.35(2)°. In contrast to NbS3-iv, NbS3-v maintains fixed a Nb-Nb bond distance of 3.358(4) Å along the chains, and it has an ABCDE repeating sequence of chain bilayers similar to NbS3-i. High resolution scanning transmission electron microscopy (HR-STEM) imaging of an exfoliated NbS3-v nanoribbon shows the continuous [NbS6] chains oriented along the b-axis. These results provide the first firmly established structural data for monoclinic NbS3. In addition, SEM images show the formation of NbS3 rings and cylinders, and a combination of powder x-ray diffraction and Raman spectroscopy provides a way to distinguish between NbS3 polymorphs.

Combination of ALDH2 and ADH1B polymorphisms is associated with smoking initiation: A large-scale cross-sectional study in a Japanese population.

PubMed

Masaoka, Hiroyuki; Ito, Hidemi; Gallus, Silvano; Watanabe, Miki; Yokomizo, Akira; Eto, Masatoshi; Matsuo, Keitaro

2017-04-01

Aldehyde dehydrogenase 2 (ALDH2; rs671, Glu504Lys) and alcohol dehydrogenase 1B (ADH1B; rs1229984, His47Arg) polymorphisms are known to strongly influence alcohol　drinking behavior. Given evidence of an association between smoking and drinking behaviors, we hypothesized that ALDH2/ADH1B polymorphisms might also be associated with smoking initiation, and conducted a cross-sectional study to examine this hypothesis. Study subjects were first-visit outpatients diagnosed not to have cancer at Aichi Cancer Center Hospital between 2001 and 2005, including 4141 never smokers and 2912 ever smokers. Unconditional logistic regression models were applied to estimate odds ratios (OR) and 95% confidence intervals (CI) for smoking initiation by comparing ever smokers with never smokers. Excessive alcohol drinking was associated with a higher likelihood of ever smoking. After adjustment for drinking behaviors, compared to individuals with ALDH2 Glu/Glu, the ORs of ever smoking were 1.71 (95% CI, 1.49-1.95) and 2.28 (1.81-2.87) among those with ALDH2 Glu/Lys and Lys/Lys, respectively. Combination of ALDH2 Lys/Lys and ADH1B His/His (i.e., the most alcohol-intolerant subpopulation) showed the highest OR [2.44 (1.84-3.23)], whereas combination of ALDH2 Glu/Glu and ADH1B Arg/Arg (i.e., the most alcohol-tolerant subpopulation) showed the lowest OR [0.83 (0.57-1.21)] compared with ALDH2 Glu/Glu and ADH1B His/His. Besides the amount and frequency of alcohol drinking, the combination of ALDH2 and ADH1B polymorphisms predicts smoking initiation. This study suggests that alcohol tolerance regulated by ALDH2 and ADH1B polymorphisms is associated with smoking initiation, and facilitates the development of targeted interventions to reduce smoking prevalence. Copyright © 2017 Elsevier B.V. All rights reserved.

The presence of the NOS3 gene polymorphism for intron 4 mitigates the beneficial effects of exercise training on ambulatory blood pressure monitoring in adults.

PubMed

Sponton, Carlos H; Esposti, Rodrigo; Rodovalho, Cynara M; Ferreira, Maycon J; Jarrete, Aline P; Anaruma, Chadi P; Bacci, Mauricio; Zanesco, Angelina

2014-06-15

The number of studies that have evaluated exercise training (ET) and nitric oxide synthase (NOS)3 gene polymorphisms is scarce. The present study was designed to evaluate the relationship between exercise training and NOS3 polymorphisms at -786T>C, 894G>T, and intron 4b/a on blood pressure (BP) using 24-h ambulatory BP monitoring (ABPM), nitrate/nitrite levels (NOx), and redox state. Eighty-six volunteers (51 ± 0.6 yr old) were genotyped into nonpolymorphic and polymorphic groups for each of the three positions of NOS3 polymorphisms. Auscultatory BP, ABPM, SOD activity, catalase activity, NOx levels, and malondialdehyde levels were measured. DNA was extracted from leukocytes, and PCR followed by sequencing was applied for genotype analysis. Aerobic ET consisted of 24 sessions for 3 days/wk for 40 min at moderate intensity. This study was performed in a double-blind and crossover format. ET was effective in lowering office BP (systolic BP: 3.2% and diastolic BP: 3%) as well as ABPM (systolic BP: 2% and diastolic BP: 1.3%). Increased SOD and catalase activity (42.6% and 15.1%, respectively) were also observed. The NOS3 polymorphism for intron 4 mitigated the beneficial effect of ET for systolic BP (nonpolymorphic group: -3.0% and polymorphic group: -0.6%) and diastolic BP (nonpolymorphic group: -3.2% and polymorphic group: -0.5%), but it was not associated with NOx level and redox state. Paradoxical responses were found for positions T786-C and G894T for the NOS3 gene. Consistently, the presence of the polymorphism for intron 4 blunted the beneficial effects of ET in middle-aged adults. Possibly, this effect might be as consequence of intron 4 acting as a short intronic repeat RNA controlling endothelial NOS activity epigenetically. Copyright © 2014 the American Physiological Society.

The POLD3 subunit of DNA polymerase δ can promote translesion synthesis independently of DNA polymerase ζ

PubMed Central

Hirota, Kouji; Yoshikiyo, Kazunori; Guilbaud, Guillaume; Tsurimoto, Toshiki; Murai, Junko; Tsuda, Masataka; Phillips, Lara G.; Narita, Takeo; Nishihara, Kana; Kobayashi, Kaori; Yamada, Kouich; Nakamura, Jun; Pommier, Yves; Lehmann, Alan; Sale, Julian E.; Takeda, Shunichi

2015-01-01

The replicative DNA polymerase Polδ consists of a catalytic subunit POLD1/p125 and three regulatory subunits POLD2/p50, POLD3/p66 and POLD4/p12. The ortholog of POLD3 in Saccharomyces cerevisiae, Pol32, is required for a significant proportion of spontaneous and UV-induced mutagenesis through its additional role in translesion synthesis (TLS) as a subunit of DNA polymerase ζ. Remarkably, chicken DT40 B lymphocytes deficient in POLD3 are viable and able to replicate undamaged genomic DNA with normal kinetics. Like its counterpart in yeast, POLD3 is required for fully effective TLS, its loss resulting in hypersensitivity to a variety of DNA damaging agents, a diminished ability to maintain replication fork progression after UV irradiation and a significant decrease in abasic site-induced mutagenesis in the immunoglobulin loci. However, these defects appear to be largely independent of Polζ, suggesting that POLD3 makes a significant contribution to TLS independently of Polζ in DT40 cells. Indeed, combining polη, polζ and pold3 mutations results in synthetic lethality. Additionally, we show in vitro that POLD3 promotes extension beyond an abasic by the Polδ holoenzyme suggesting that while POLD3 is not required for normal replication, it may help Polδ to complete abasic site bypass independently of canonical TLS polymerases. PMID:25628356

The E1 beta-subunit of pyruvate dehydrogenase is surface-expressed in Lactobacillus plantarum and binds fibronectin.

PubMed

Vastano, Valeria; Salzillo, Marzia; Siciliano, Rosa A; Muscariello, Lidia; Sacco, Margherita; Marasco, Rosangela

2014-01-01

Lactobacillus plantarum is among the species with a probiotic activity. Adhesion of probiotic bacteria to host tissues is an important principle for strain selection, because it represents a crucial step in the colonization process of either pathogens or commensals. Most bacterial adhesins are proteins, and a major target for them is fibronectin, an extracellular matrix glycoprotein. In this study we demonstrate that PDHB, a component of the pyruvate dehydrogenase complex, is a factor contributing to fibronectin-binding in L. plantarum LM3. By means of fibronectin overlay immunoblotting assay, we identified a L. plantarum LM3 surface protein with apparent molecular mass of 35 kDa. Mass spectrometric analysis shows that this protein is the pyruvate dehydrogenase E1 beta-subunit (PDHB). The corresponding pdhB gene is located in a 4-gene cluster encoding pyruvate dehydrogenase. In LM3-B1, carrying a null mutation in pdhB, the 35 kDa adhesin was not anymore detectable by immunoblotting assay. Nevertheless, the pdhB null mutation did not abolish pdhA, pdhC, and pdhD transcription in LM3-B1. By adhesion assays, we show that LM3-B1 cells bind to immobilized fibronectin less efficiently than wild type cells. Moreover, we show that pdhB expression is negatively regulated by the CcpA protein and is induced by bile. Copyright © 2013. Published by Elsevier GmbH.

Characterization of North American Armillaria species: Genetic relationships determined by ribosomal DNA sequences and AFLP markers

Treesearch

M. -S. Kim; N. B. Klopfenstein; J. W. Hanna; G. I. McDonald

2006-01-01

Phylogenetic and genetic relationships among 10 North American Armillaria species were analysed using sequence data from ribosomal DNA (rDNA), including intergenic spacer (IGS-1), internal transcribed spacers with associated 5.8S (ITS + 5.8S), and nuclear large subunit rDNA (nLSU), and amplified fragment length polymorphism (AFLP) markers. Based on rDNA sequence data,...

Early Treatment in Shock

DTIC Science & Technology

2009-06-01

concentrations. e . In analyzing the protein subunits which comprise the proteasome, we found over-expression of LMP2 protease as compared with constitutively...and Enteral Nutrition, Jan 27-31, 2007 (Phoenix, Arizona). (Presentation and abstract) 10. Smit J, Kaltashov IA, Cotter RJ, Vinogradov E , Perry MB...of human TLR4 by Escherichia coli and Shigella flexneiri 2a lipopolysaccharide: Combined effects of lipid A acylation state and TRL4 polymorphisms on

Evolutionary history of the European whitefish Coregonus lavaretus (L.) species complex as inferred from mtDNA phylogeography and gill-raker numbers.

PubMed

Østbye, K; Bernatchez, L; Naesje, T F; Himberg, K-J M; Hindar, K

2005-12-01

We compared mitochondrial DNA and gill-raker number variation in populations of the European whitefish Coregonus lavaretus (L.) species complex to illuminate their evolutionary history, and discuss mechanisms behind diversification. Using single-strand conformation polymorphism (SSCP) and sequencing 528 bp of combined parts of the cytochrome oxidase b (cyt b) and NADH dehydrogenase subunit 3 (ND3) mithochondrial DNA (mtDNA) regions, we documented phylogeographic relationships among populations and phylogeny of mtDNA haplotypes. Demographic events behind geographical distribution of haplotypes were inferred using nested clade analysis (NCA) and mismatch distribution. Concordance between operational taxonomical groups, based on gill-raker numbers, and mtDNA patterns was tested. Three major mtDNA clades were resolved in Europe: a North European clade from northwest Russia to Denmark, a Siberian clade from the Arctic Sea to southwest Norway, and a South European clade from Denmark to the European Alps, reflecting occupation in different glacial refugia. Demographic events inferred from NCA were isolation by distance, range expansion, and fragmentation. Mismatch analysis suggested that clades which colonized Fennoscandia and the Alps expanded in population size 24 500-5800 years before present, with minute female effective population sizes, implying small founder populations during colonization. Gill-raker counts did not commensurate with hierarchical mtDNA clades, and poorly with haplotypes, suggesting recent origin of gill-raker variation. Whitefish designations based on gill-raker numbers were not associated with ancient clades. Lack of congruence in morphology and evolutionary lineages implies that the taxonomy of this species complex should be reconsidered.

The biosynthesis, processing, and secretion of laminin by human choriocarcinoma cells.

PubMed

Peters, B P; Hartle, R J; Krzesicki, R F; Kroll, T G; Perini, F; Balun, J E; Goldstein, I J; Ruddon, R W

1985-11-25

Laminin, a glycoprotein component of basal laminae, is synthesized and secreted in culture by a human malignant cell line (JAR) derived from gestational choriocarcinoma. Biosynthetically labeled human laminin subunits A (Mr approximately 400,000) and B (Mr = 200,000 doublet) are glycoslyated with asparagine-linked high mannose oligosaccharides that are processed to complex oligosaccharides before the laminin molecule is externalized by the cell. The rate-limiting step in the processing of the asparagine-linked glycans of laminin is at the point of action of alpha-mannosidase I since the principal laminin forms that accumulate in JAR cells contain Man9GlcNAc2 and Man8GlcNAc2 oligosaccharide units. The combination of subunits to form the disulfide-linked laminin molecule (Mr approximately 950,000) occurs rapidly within the cell at a time when the subunits contain these high mannose oligosaccharides. The production of laminin is limited by the availability of the A subunit such that excess B subunit forms accumulate intracellularly as uncombined B and a disulfide-linked B dimer. Pulse-chase kinetic studies establish these B forms as intermediates in the assembly of the laminin molecule. The fully assembled laminin undergoes further oligosaccharide processing and translocation to the cell surface, but uncombined B and B dimer are neither processed nor secreted to any significant extent. Therefore, laminin subunit combination appears to be a prerequisite for intracellular translocation, processing, and secretion. The mature laminin that contains complex oligosaccharides does not accumulate intracellularly but is rapidly externalized upon completion, either secreted into the culture medium (25%) or associated with the cell surface (75%) as determined by susceptibility to degradation by trypsin. About one-third of the laminin molecules secreted or shed by JAR cells into the chase medium contain a smaller A subunit form that appears to have been modified by limited proteolytic cleavage. The putative proteolytic event is closely timed to the release of the laminin into the culture medium.

Nuclear respiratory factor 2 regulates the expression of the same NMDA receptor subunit genes as NRF-1: both factors act by a concurrent and parallel mechanism to couple energy metabolism and synaptic transmission.

PubMed

Priya, Anusha; Johar, Kaid; Wong-Riley, Margaret T T

2013-01-01

Neuronal activity and energy metabolism are tightly coupled processes. Previously, we found that nuclear respiratory factor 1 (NRF-1) transcriptionally co-regulates energy metabolism and neuronal activity by regulating all 13 subunits of the critical energy generating enzyme, cytochrome c oxidase (COX), as well as N-methyl-d-aspartate (NMDA) receptor subunits 1 and 2B, GluN1 (Grin1) and GluN2B (Grin2b). We also found that another transcription factor, nuclear respiratory factor 2 (NRF-2 or GA-binding protein) regulates all subunits of COX as well. The goal of the present study was to test our hypothesis that NRF-2 also regulates specific subunits of NMDA receptors, and that it functions with NRF-1 via one of three mechanisms: complementary, concurrent and parallel, or a combination of complementary and concurrent/parallel. By means of multiple approaches, including in silico analysis, electrophoretic mobility shift and supershift assays, in vivo chromatin immunoprecipitation of mouse neuroblastoma cells and rat visual cortical tissue, promoter mutations, real-time quantitative PCR, and western blot analysis, NRF-2 was found to functionally regulate Grin1 and Grin2b genes, but not any other NMDA subunit genes. Grin1 and Grin2b transcripts were up-regulated by depolarizing KCl, but silencing of NRF-2 prevented this up-regulation. On the other hand, over-expression of NRF-2 rescued the down-regulation of these subunits by the impulse blocker TTX. NRF-2 binding sites on Grin1 and Grin2b are conserved among species. Our data indicate that NRF-2 and NRF-1 operate in a concurrent and parallel manner in mediating the tight coupling between energy metabolism and neuronal activity at the molecular level. Copyright © 2012 Elsevier B.V. All rights reserved.

Transcobalamin 776C→G polymorphism is associated with peripheral neuropathy in elderly individuals with high folate intake.

PubMed

Sawaengsri, Hathairat; Bergethon, Peter R; Qiu, Wei Qiao; Scott, Tammy M; Jacques, Paul F; Selhub, Jacob; Paul, Ligi

2016-12-01

The 776C→G polymorphism of the vitamin B-12 transport protein transcobalamin gene (TCN2) (rs1801198; Pro259Arg) is associated with a lower holotranscobalamin concentration in plasma. This effect may reduce the availability of vitamin B-12 to tissues even when vitamin B-12 intake is adequate. Clinical outcomes associated with vitamin B-12 insufficiency could potentially be worsened by high folate intake. We determined the association of the TCN2 776C→G polymorphism and folate intake with peripheral neuropathy in elders with normal plasma concentrations of vitamin B-12. Participants in this cross-sectional study (n = 171) were from a cohort of community-based, home-bound elderly individuals aged ≥60 y who underwent an evaluation by physicians including an assessment for peripheral neuropathy. Participants were administered food-frequency and general health status questionnaires, anthropometric measurements were taken, and a fasting blood sample from each subject was collected. Odds of neuropathy were 3-fold higher for GG genotypes than for CC genotypes (OR: 3.33; 95% CI: 1.15, 9.64). When folate intake was >2 times the Recommended Dietary Allowance (800 μg), GG genotypes had 6.9-fold higher odds of neuropathy than CC genotypes (OR: 6.9; 95% CI: 1.31, 36.36). There was no difference between the genotypes in the odds of peripheral neuropathy when folate intake was ≤800 μg (OR: 1.5; 95% CI: 0.18, 12.33). The TCN2 776C→G polymorphism is associated with increased odds of peripheral neuropathy in the elderly, even with a normal vitamin B-12 status, especially if their folate intake is >2 times the Recommended Dietary Allowance. © 2016 American Society for Nutrition.

An active Mitochondrial Complex II Present in Mature Seeds Contains an Embryo-Specific Iron-Sulfur Subunit Regulated by ABA and bZIP53 and Is Involved in Germination and Seedling Establishment.

PubMed

Restovic, Franko; Espinoza-Corral, Roberto; Gómez, Isabel; Vicente-Carbajosa, Jesús; Jordana, Xavier

2017-01-01

Complex II (succinate dehydrogenase) is an essential mitochondrial enzyme involved in both the tricarboxylic acid cycle and the respiratory chain. In Arabidopsis thaliana , its iron-sulfur subunit (SDH2) is encoded by three genes, one of them ( SDH2.3 ) being specifically expressed during seed maturation in the embryo. Here we show that seed SDH2.3 expression is regulated by abscisic acid (ABA) and we define the promoter region (-114 to +49) possessing all the cis -elements necessary and sufficient for high expression in seeds. This region includes between -114 and -32 three ABRE (ABA-responsive) elements and one RY-enhancer like element, and we demonstrate that these elements, although necessary, are not sufficient for seed expression, our results supporting a role for the region encoding the 5' untranslated region (+1 to +49). The SDH2.3 promoter is activated in leaf protoplasts by heterodimers between the basic leucine zipper transcription factors bZIP53 (group S1) and bZIP10 (group C) acting through the ABRE elements, and by the B3 domain transcription factor ABA insensitive 3 (ABI3). The in vivo role of bZIP53 is further supported by decreased SDH2.3 expression in a knockdown bzip53 mutant. By using the protein synthesis inhibitor cycloheximide and sdh2 mutants we have been able to conclusively show that complex II is already present in mature embryos before imbibition, and contains mainly SDH2.3 as iron-sulfur subunit. This complex plays a role during seed germination sensu-stricto since we have previously shown that seeds lacking SDH2.3 show retarded germination and now we demonstrate that low concentrations of thenoyltrifluoroacetone, a complex II inhibitor, also delay germination. Furthermore, complex II inhibitors completely block hypocotyl elongation in the dark and seedling establishment in the light, highlighting an essential role of complex II in the acquisition of photosynthetic competence and the transition from heterotrophy to autotrophy.

Mutations in POLR3A and POLR3B Encoding RNA Polymerase III Subunits Cause an Autosomal-Recessive Hypomyelinating Leukoencephalopathy

PubMed Central

Saitsu, Hirotomo; Osaka, Hitoshi; Sasaki, Masayuki; Takanashi, Jun-ichi; Hamada, Keisuke; Yamashita, Akio; Shibayama, Hidehiro; Shiina, Masaaki; Kondo, Yukiko; Nishiyama, Kiyomi; Tsurusaki, Yoshinori; Miyake, Noriko; Doi, Hiroshi; Ogata, Kazuhiro; Inoue, Ken; Matsumoto, Naomichi

2011-01-01

Congenital hypomyelinating disorders are a heterogeneous group of inherited leukoencephalopathies characterized by abnormal myelin formation. We have recently reported a hypomyelinating syndrome characterized by diffuse cerebral hypomyelination with cerebellar atrophy and hypoplasia of the corpus callosum (HCAHC). We performed whole-exome sequencing of three unrelated individuals with HCAHC and identified compound heterozygous mutations in POLR3B in two individuals. The mutations include a nonsense mutation, a splice-site mutation, and two missense mutations at evolutionally conserved amino acids. Using reverse transcription-PCR and sequencing, we demonstrated that the splice-site mutation caused deletion of exon 18 from POLR3B mRNA and that the transcript harboring the nonsense mutation underwent nonsense-mediated mRNA decay. We also identified compound heterozygous missense mutations in POLR3A in the remaining individual. POLR3A and POLR3B encode the largest and second largest subunits of RNA Polymerase III (Pol III), RPC1 and RPC2, respectively. RPC1 and RPC2 together form the active center of the polymerase and contribute to the catalytic activity of the polymerase. Pol III is involved in the transcription of small noncoding RNAs, such as 5S ribosomal RNA and all transfer RNAs (tRNA). We hypothesize that perturbation of Pol III target transcription, especially of tRNAs, could be a common pathological mechanism underlying POLR3A and POLR3B mutations. PMID:22036171

NF-kappaB binds to a polymorphic repressor element in the MMP-3 promoter.

PubMed

Borghaei, Ruth C; Rawlings, P Lyle; Javadi, Masoud; Woloshin, Joanna

2004-03-26

A 5T/6T polymorphic site in the matrix metalloproteinase-3 (MMP-3) promoter has been identified as a repressor element involved in inhibiting induction of MMP-3 transcription by interleukin 1; and the 6T allele has been associated with decreased expression of MMP-3 as compared to the 5T allele. Zinc-binding protein-89 (ZBP-89) was cloned from a yeast one-hybrid assay via its ability to interact with this site, but when the protein was over-expressed, it resulted in activation of the MMP-3 promoter rather than repression. Here we show that in nuclear extracts isolated from human gingival fibroblasts stimulated with IL-1, this site is bound by p50 and p65 components of NF-kappaB in addition to ZBP-89, and that recombinant p50 binds preferentially to the 6T binding site. These results are consistent with a role for NF-kappaB in limiting the cytokine induced expression of MMP-3.

Epigenetic regulation of dorsal raphe GABA(B1a) associated with isolation-induced abnormal responses to social stimulation in mice.

PubMed

Araki, Ryota; Hiraki, Yosuke; Nishida, Shoji; Kuramoto, Nobuyuki; Matsumoto, Kinzo; Yabe, Takeshi

2016-02-01

In isolation-reared mice, social encounter stimulation induces locomotor hyperactivity and activation of the dorsal raphe nucleus (DRN), suggesting that dysregulation of dorsal raphe function may be involved in abnormal behaviors. In this study, we examined the involvement of dorsal raphe GABAergic dysregulation in the abnormal behaviors of isolation-reared mice. We also studied an epigenetic mechanism underlying abnormalities of the dorsal raphe GABAergic system. Both mRNA and protein levels of GABA(B1a), a GABA(B) receptor subunit, were increased in the DRN of isolation-reared mice, compared with these levels in group-reared mice. In contrast, mRNA levels for other GABAergic system-related genes (GABA(A) receptor α1, β2 and γ2 subunits, GABA(B) receptor 1b and 2 subunits, and glutamate decarboxylase 67 and 65) were unchanged. Intra-DRN microinjection of 0.06 nmol baclofen (a GABA(B) receptor agonist) exacerbated encounter-induced hyperactivity and aggressive behavior, while microinjection of 0.3 nmol phaclofen (a GABA(B) receptor antagonist) attenuated encounter-induced hyperactivity and aggressive behavior in isolation-reared mice. Furthermore, microinjection of 0.06 nmol baclofen elicited encounter-induced hyperactivity in group-reared mice. Neither baclofen nor phaclofen affected immobility time in the forced swim test and hyperactivity in a novel environment of isolation reared mice. Bisulfite sequence analyses revealed that the DNA methylation level of the CpG island around the transcription start site (TSS) of GABA(B1a) was decreased in the DRN of isolation-reared mice. Chromatin immunoprecipitation analysis showed that histone H3 was hyperacetylated around the TSS of GABA(B1a) in the DRN of isolation-reared mice. These findings indicate that an increase in dorsal raphe GABA(B1a) expression via epigenetic regulation is associated with abnormal responses to social stimulation such as encounter-induced hyperactivity and aggressive behavior in isolation-reared mice. Copyright © 2015 Elsevier Ltd. All rights reserved.

The NMDA Receptor Subunit NR2b: Effects on LH Release and GnRH Gene Expression in Young and Middle-aged Female Rats, with Modulation by Estradiol

PubMed Central

Maffucci, Jacqueline A.; Walker, Deena M.; Ikegami, Aiko; Woller, Michael J.; Gore, Andrea C.

2008-01-01

The loss of reproductive capacity during aging involves changes in the neural regulation of the hypothalamic gonadotropin-releasing hormone (GnRH) neurons controlling reproduction. This neuronal circuitry includes glutamate receptors on GnRH neurons. Previously, we reported an increase in the expression of the NR2b subunit protein of the NMDA receptor on GnRH neurons in middle-aged compared to young female rats. Here, we examined the functional implications of the NR2b subunit on the onset of reproductive aging, using an NR2b-specific antagonist ifenprodil. Young (3–5 mos.) and middle-aged (10–13 mos.) female rats were ovariectomized (OVX), 17β-estradiol (E2) or vehicle (cholesterol) treated, and implanted with a jugular catheter. Serial blood sampling was undertaken every 10 minutes for 4 hours, with ifenprodil (10mg/kg) or vehicle injected (i.p.) after one hour of baseline sampling. The pulsatile release of pituitary LH and levels of GnRH mRNA in hypothalamus were quantified as indices of the reproductive axis. Our results showed effects of ifenprodil on both endpoints. In OVX rats given cholesterol, neither age nor ifenprodil had any effects on LH release. In E2-treated rats, aging was associated with significant decreases in pulsatile LH release. Additionally, ifenprodil stimulated parameters of pulsatile LH release in both young and middle-aged animals. Ifenprodil had few effects on GnRH mRNA; the only significant effect of ifenprodil was found in the middle-aged, cholesterol group. Together, these findings support a role for the NR2b subunit of the NMDAR in GnRH/LH regulation. Because most of these effects were exhibited on pituitary LH release in the absence of a concomitant change in GnRH gene expression, it is likely that NMDA receptors containing the NR2b subunit plays a role in GnRH-induced LH release, independent of de novo GnRH gene expression. PMID:18025808

[Influence of interleukin-1 beta gene polymorphism and childhood maltreatment on antidepressant treatment].

PubMed

Chen, Ying; Zhang, Zhijun; Xu, Zhi; Pu, Mengjia; Geng, Leiyu

2015-12-01

To explore the influence of interleukin-1 beta (IL1B) gene polymorphism and childhood maltreatment on antidepressant treatment. Two hundred and four patients with major depressive disorder (MDD) have received treatment with single antidepressant drugs and were followed up for 8 weeks. Hamilton depression scale-17 (HAMD-17) was used to evaluate the severity of depressive symptoms and therapeutic effect. Childhood maltreatment was assessed using Childhood Trauma Questionnaire, a 28-item Short Form (CTQ-SF). Single nucleotide polymorphism (SNP) of the IL1B gene was determined using a SNaPshot method. Correlation of rs16944 gene polymorphism with response to treatment was analyzed using Unphased 3.0.13 software. The main and interactive effects of SNP and childhood maltreatment on the antidepressant treatment were analyzed using Logistic regression analysis. No significant difference of gender, age, year of education, family history, episode time, and antidepressant agents was detected between the remitters and non-remitters. Association analysis has found that the SNP rs16944 in the IL1B AA genotype carriers antidepressant response was poorer (χ2=3.931, P=0.047). No significant difference was detected in the CTQ scores between the two groups. Genetic and environmental interaction analysis has demonstrated a significant correlation between rs16944 AA genotype and childhood maltreatment and poorer response to antidepressant treatment. The SNP rs16944 in the IL1B gene and its interaction with childhood maltreatment may influence the effect of antidepressant treatment for patients with MDD.

Activation of the EBV/C3d receptor (CR2, CD21) on human B lymphocyte surface triggers tyrosine phosphorylation of the 95-kDa nucleolin and its interaction with phosphatidylinositol 3 kinase.

PubMed

Barel, M; Le Romancer, M; Frade, R

2001-03-01

We previously demonstrated that CR2 activation on human B lymphocyte surface triggered tyrosine phosphorylation of a p95 component and its interaction with p85 subunit of phosphatidylinositol 3' (PI 3) kinase. Despite identical molecular mass of 95 kDa, this tyrosine phosphorylated p95 molecule was not CD19, the proto-oncogene Vav, or the adaptator Gab1. To identify this tyrosine phosphorylated p95 component, we first purified it by affinity chromatography on anti-phosphotyrosine mAb covalently linked to Sepharose 4B, followed by polyacrylamide gel electrophoresis. Then, the isolated 95-kDa tyrosine phosphorylated band was submitted to amino acid analysis by mass spectrometry; the two different isolated peptides were characterized by amino acid sequences 100% identical with two different domains of nucleolin, localized between aa 411--420 and 611--624. Anti-nucleolin mAb was used to confirm the antigenic properties of this p95 component. Functional studies demonstrated that CR2 activation induced, within a brief span of 2 min, tyrosine phosphorylation of nucleolin and its interaction with Src homology 2 domains of the p85 subunit of PI 3 kinase and of 3BP2 and Grb2, but not with Src homology 2 domains of Fyn and Gap. These properties of nucleolin were identical with those of the p95 previously described and induced by CR2 activation. Furthermore, tyrosine phosphorylation of nucleolin was also induced in normal B lymphocytes by CR2 activation but neither by CD19 nor BCR activation. These data support that tyrosine phosphorylation of nucleolin and its interaction with PI 3 kinase p85 subunit constitute one of the earlier steps in the specific intracellular signaling pathway of CR2.

SIRT1 overexpression decreases cisplatin-induced acetylation of NF-{kappa}B p65 subunit and cytotoxicity in renal proximal tubule cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jung, Yu Jin; Lee, Jung Eun; Lee, Ae Sin

2012-03-09

Highlights: Black-Right-Pointing-Pointer Cisplatin increases acetylation of NF-{kappa}B p65 subunit in HK2 cells. Black-Right-Pointing-Pointer SIRT1 overexpression decreases cisplatin-induced p65 acetylation and -cytotoxicity. Black-Right-Pointing-Pointer Resveratrol decreased cisplatin-induced cell viability through deacetylation of p65. -- Abstract: As the increased acetylation of p65 is linked to nuclear factor-{kappa}B (NF-{kappa}B) activation, the regulation of p65 acetylation can be a potential target for the treatment of inflammatory injury. Cisplatin-induced nephrotoxicity is an important issue in chemotherapy of cancer patients. SIRT1, nicotinamide adenine dinucleotide (NAD{sup +})-dependent protein deacetylase, has been implicated in a variety of cellular processes such as inflammatory injury and the control of multidrug resistancemore » in cancer. However, there is no report on the effect of SIRT1 overexpression on cisplatin-induced acetylation of p65 subunit of NF-{kappa}B and cell injury. To investigate the effect of SIRT1 in on cisplatin-induced acetylation of p65 subunit of NF-{kappa}B and cell injury, HK2 cells were exposed with SIRT1 overexpression, LacZ adenovirus or dominant negative adenovirus after treatment with cisplatin. While protein expression of SIRT1 was decreased by cisplatin treatment compared with control buffer treatment, acetylation of NF-{kappa}B p65 subunit was significantly increased after treatment with cisplatin. Overexpression of SIRT1 ameliorated the increased acetylation of p65 of NF-{kappa}B during cisplatin treatment and cisplatin-induced cytotoxicity. Further, treatment of cisplatin-treated HK2 cells with resveratrol, a SIRT1 activator, also decreased acetylation of NF-{kappa}B p65 subunit and cisplatin-induced increase of the cell viability in HK2 cells. Our findings suggests that the regulation of acetylation of p65 of NF-{kappa}B through SIRT1 can be a possible target to attenuate cisplatin-induced renal cell damage.« less

Neutron diffraction and μ SR studies of two polymorphs of nickel niobate NiNb2O6

NASA Astrophysics Data System (ADS)

Munsie, T. J. S.; Wilson, M. N.; Millington, A.; Thompson, C. M.; Flacau, R.; Ding, C.; Guo, S.; Gong, Z.; Aczel, A. A.; Cao, H. B.; Williams, T. J.; Dabkowska, H. A.; Ning, F.; Greedan, J. E.; Luke, G. M.

2017-10-01

Neutron diffraction and muon spin relaxation (μ SR ) studies are presented for the newly characterized polymorph of NiNb2O6 (β -NiNb2O6) with space group P4 2/n and μ SR data only for the previously known columbite structure polymorph with space group P b c n . The magnetic structure of the P4 2/n form was determined from neutron diffraction using both powder and single-crystal data. Powder neutron diffraction determined an ordering wave vector k ⃗=(1/2 ,1/2 ,1/2 ) . Single-crystal data confirmed the same k ⃗ vector and showed that the correct magnetic structure consists of antiferromagnetically coupled chains running along the a or b axis in adjacent Ni2 + layers perpendicular to the c axis, which is consistent with the expected exchange interaction hierarchy in this system. The refined magnetic structure is compared with the known magnetic structures of the closely related trirutile phases, NiSb2O6 and NiTa2O6 . μ SR data finds a transition temperature of TN˜15 K for this system, while the columbite polymorph exhibits a lower TN=5.7 (3 ) K. Our μ SR measurements also allowed us to estimate the critical exponent of the order parameter β for each polymorph. We found β =0.25 (3 ) and 0.16(2) for the β and columbite polymorphs, respectively. The single-crystal neutron scattering data give a value for the critical exponent β =0.28 (3 ) for β -NiNb2O6 , in agreement with the μ SR value. While both systems have β values less than 0.3, which is indicative of reduced dimensionality, this effect appears to be much stronger for the columbite system. In other words, although both systems appear to be well described by S =1 spin chains, the interchain interactions in the β polymorph are likely much larger.

Cryo-EM structure of the serotonin 5-HT1B receptor coupled to heterotrimeric Go.

PubMed

García-Nafría, Javier; Nehmé, Rony; Edwards, Patricia C; Tate, Christopher G

2018-06-20

G-protein-coupled receptors (GPCRs) form the largest family of receptors encoded by the human genome (around 800 genes). They transduce signals by coupling to a small number of heterotrimeric G proteins (16 genes encoding different α-subunits). Each human cell contains several GPCRs and G proteins. The structural determinants of coupling of G s to four different GPCRs have been elucidated 1-4 , but the molecular details of how the other G-protein classes couple to GPCRs are unknown. Here we present the cryo-electron microscopy structure of the serotonin 5-HT 1B receptor (5-HT 1B R) bound to the agonist donitriptan and coupled to an engineered G o heterotrimer. In this complex, 5-HT 1B R is in an active state; the intracellular domain of the receptor is in a similar conformation to that observed for the β 2 -adrenoceptor (β 2 AR) 3 or the adenosine A 2A receptor (A 2A R) 1 in complex with G s . In contrast to the complexes with G s , the gap between the receptor and the Gβ-subunit in the G o -5-HT 1B R complex precludes molecular contacts, and the interface between the Gα-subunit of G o and the receptor is considerably smaller. These differences are likely to be caused by the differences in the interactions with the C terminus of the G o α-subunit. The molecular variations between the interfaces of G o and G s in complex with GPCRs may contribute substantially to both the specificity of coupling and the kinetics of signalling.

The Val192Leu mutation in the alpha-subunit of beta-hexosaminidase A is not associated with the B1-variant form of Tay-Sachs disease.

PubMed

Hou, Y; Vavougios, G; Hinek, A; Wu, K K; Hechtman, P; Kaplan, F; Mahuran, D J

1996-07-01

Substitution mutations adversely affecting the alpha-subunit of beta-hexosaminidase A (alphabeta) (EC 3.2.1.52) result in Tay-Sachs disease. The majority affect the initial folding of the pro-alpha chain in the endoplasmic reticulum, resulting in its retention and degradation. A much less common occurrence is a mutation that specifically affects an "active-site" residue necessary for substrate binding and/or catalysis. In this case, hexosaminidase A is present in the lysosome, but it lacks all alpha-specific activity. This biochemical phenotype is referred to as the "B1-variant form" of Tay-Sachs disease. Kinetic analysis of suspected B1-variant mutations is complex because hexosaminidase A is heterodimeric and both subunits possess similar active sites. In this report, we examine a previously identified B1-variant mutation, alpha-Val192Leu. Chinese hamster ovary cells were permanently cotransfected with an alpha-cDNA-construct encoding the substitution and a mutant beta-cDNA (beta-Arg211Lys), encoding a beta-subunit that is inactive but normal in all other respects. We were surprised to find that the Val192Leu substitution, produced a pro-alpha chain that did not form alpha-beta dimers and was not transported to the lysosome. Finally, we reexamined the hexosaminidase activity and protein levels in the fibroblasts from the original patient. These data were also not consistent with the biochemical phenotype of the B1 variant of Tay-Sachs disease previously reported to be present. Thus, we conclude that the Val192Leu substitution does not specifically affect the alpha-active site.

NMDA receptor subunits and associated signaling molecules mediating antidepressant-related effects of NMDA-GluN2B antagonism

PubMed Central

Kiselycznyk, Carly; Jury, Nicholas; Halladay, Lindsay; Nakazawa, Kazu; Mishina, Masayoshi; Sprengel, Rolf; Grant, Seth G.N.; Svenningsson, Per; Holmes, Andrew

2015-01-01

Drugs targeting the glutamate N-methyl-D-aspartate receptor (NMDAR) may be efficacious for treating mood disorders, as exemplified by the rapid antidepressant effects produced by single administration of the NMDAR antagonist ketamine. Though the precise mechanisms underlying the antidepressant-related effects of NMDAR antagonism remain unclear, recent studies implicate specific NMDAR subunits, including GluN2A and GluN2B, as well as the alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptor (AMPAR) subunit glutamate receptor interacting molecule, PSD-95. Here, integrating mutant and pharmacological in mice, we investigated the contribution of these subunits and molecules to antidepressant-related behaviors and the antidepressant-related effects of the GluN2B blocker, Ro 25-6981. We found that global deletion of GluA1 or PSD-95 reduced forced swim test (FST) immobility, mimicking the antidepressant-related effect produced by systemically administered Ro 25-6981 in C57BL/6J mice. Moreover, the FST antidepressant-like effects of systemic Ro 25-6981 were intact in mutants with global GluA1 deletion or GluN1 deletion in forebrain interneurons, but were absent in mutants constitutively lacking GluN2A or PSD-95. Next, we found that microinfusing Ro 25-6981 into the medial prefrontal cortex (mPFC), but not basolateral amygdala, of C57BL/6J mice was sufficient to produce an antidepressant-like effect. Together, these findings extend and refine current understanding of the mechanisms mediating antidepressant-like effects produced by NMDAR-GluN2B antagonists, and may inform the development of a novel class of medications for treating depression that target the GluN2B subtype of NMDAR. PMID:25800971

Arabidopsis PHOSPHOTYROSYL PHOSPHATASE ACTIVATOR Is Essential for PROTEIN PHOSPHATASE 2A Holoenzyme Assembly and Plays Important Roles in Hormone Signaling, Salt Stress Response, and Plant Development1[W][OPEN

PubMed Central

Chen, Jian; Hu, Rongbin; Zhu, Yinfeng; Shen, Guoxin; Zhang, Hong

2014-01-01

PROTEIN PHOSPHATASE 2A (PP2A) is a major group of serine/threonine protein phosphatases in eukaryotes. It is composed of three subunits: scaffolding subunit A, regulatory subunit B, and catalytic subunit C. Assembly of the PP2A holoenzyme in Arabidopsis (Arabidopsis thaliana) depends on Arabidopsis PHOSPHOTYROSYL PHOSPHATASE ACTIVATOR (AtPTPA). Reduced expression of AtPTPA leads to severe defects in plant development, altered responses to abscisic acid, ethylene, and sodium chloride, and decreased PP2A activity. In particular, AtPTPA deficiency leads to decreased methylation in PP2A-C subunits (PP2Ac). Complete loss of PP2Ac methylation in the suppressor of brassinosteroid insensitive1 mutant leads to 30% reduction of PP2A activity, suggesting that PP2A with a methylated C subunit is more active than PP2A with an unmethylated C subunit. Like AtPTPA, PP2A-A subunits are also required for PP2Ac methylation. The interaction between AtPTPA and PP2Ac is A subunit dependent. In addition, AtPTPA deficiency leads to reduced interactions of B subunits with C subunits, resulting in reduced functional PP2A holoenzyme formation. Thus, AtPTPA is a critical factor for committing the subunit A/subunit C dimer toward PP2A heterotrimer formation. PMID:25281708

The interaction of miR-34b/c polymorphisms and negative life events increases susceptibility to major depressive disorder in Han Chinese population.

PubMed

Xu, Cheng; Yang, Chunxia; Zhang, Aixia; Xu, Yong; Li, Xinrong; Liu, Zhifen; Liu, Sha; Sun, Ning; Zhang, Kerang

2017-06-09

Previous studies have shown that microRNAs(miRNAs) are involved in the pathogenesis of MDD; in particular, miR-34b/c has been implicated in MDD risk and found to exert antidepressant effects. However, the effects of miR-34b/c polymorphisms on MDD risk have not been investigated. In this study, we evaluated the effect of miR-34b/c gene polymorphisms and their interaction with negative life events in relation to MDD, using data from 381 Han Chinese patients with MDD and 291 healthy volunteers. Allelic, genotypic, haplotypic, and gene-environment associations were analyzed using UNPHASED and SPSS software. After discarding data with extremely severe negative life events in our study population, we found an association between rs4938723, rs2187473 polymorphisms and MDD in the dominant models (TC/CC vs. TT, OR=1.45, P=0.027; TC/CC vs. TT, OR=3.32, P=0.030). In haplotype analysis, the C-G haplotype (rs4938723/rs28757623) showed the strongest association with MDD (OR=1.95, P=0.026). Additionally, we found significant gene-environment combination rs4938723 C allele, rs28757623 G allele and high level of negative life events (C-G-HN) was significantly associated with MDD (OR, 3.85; 95% CI, 1.62-9.13). In addition, the combination of (C-C-HN) is of significance (OR, 2.99; 95% CI, 1.36-6.60), indicating that the rs28757623 C allele may contribute to the risk of MDD as well. The sample size was small and the role of miR-34b/c polymorphisms for MDD should be assessed using independent samples from other ethnic populations. Our results suggest that miR-34b/c is a susceptibility factor for MDD stratified by negative life events and that rs4938723 is a significant association locus for gene-environment interaction in relation to MDD risk. Copyright © 2017 Elsevier B.V. All rights reserved.

The small GTPase Arl8b regulates assembly of the mammalian HOPS complex on lysosomes

PubMed Central

Khatter, Divya; Raina, Vivek B.; Dwivedi, Devashish; Sindhwani, Aastha; Bahl, Surbhi; Sharma, Mahak

2015-01-01

The homotypic fusion and protein sorting (HOPS) complex is a multi-subunit complex conserved from yeast to mammals that regulates late endosome and lysosome fusion. However, little is known about how the HOPS complex is recruited to lysosomes in mammalian cells. Here, we report that the small GTPase Arl8b, but not Rab7 (also known as RAB7A), is essential for membrane localization of the human (h)Vps41 subunit of the HOPS complex. Assembly of the core HOPS subunits to Arl8b- and hVps41-positive lysosomes is guided by their subunit–subunit interactions. RNA interference (RNAi)-mediated depletion of hVps41 resulted in the impaired degradation of EGFR that was rescued upon expression of wild-type but not an Arl8b-binding-defective mutant of hVps41, suggesting that Arl8b-dependent lysosomal localization of hVps41 is required for its endocytic function. Furthermore, we have also identified that the Arl8b effector SKIP (also known as PLEKHM2) interacts with and recruits HOPS subunits to Arl8b and kinesin-positive peripheral lysosomes. Accordingly, RNAi-mediated depletion of SKIP impaired lysosomal trafficking and degradation of EGFR. These findings reveal that Arl8b regulates the association of the human HOPS complex with lysosomal membranes, which is crucial for the function of this tethering complex in endocytic degradation. PMID:25908847

Polymorphisms in genes of interleukin 12 and its receptors and their association with protection against severe malarial anaemia in children in western Kenya.

PubMed

Zhang, Lyna; Prather, Donald; Vanden Eng, Jodi; Crawford, Sara; Kariuki, Simon; ter Kuile, Feiko; Terlouw, Dianne; Nahlen, Bernard; Lal, Altaf A; Slutsker, Laurence; Udhayakumar, Venkatachalam; Shi, Ya Ping

2010-03-29

Malarial anaemia is characterized by destruction of malaria infected red blood cells and suppression of erythropoiesis. Interleukin 12 (IL12) significantly boosts erythropoietic responses in murine models of malarial anaemia and decreased IL12 levels are associated with severe malarial anaemia (SMA) in children. Based on the biological relevance of IL12 in malaria anaemia, the relationship between genetic polymorphisms of IL12 and its receptors and SMA was examined. Fifty-five tagging single nucleotide polymorphisms covering genes encoding two IL12 subunits, IL12A and IL12B, and its receptors, IL12RB1 and IL12RB2, were examined in a cohort of 913 children residing in Asembo Bay region of western Kenya. An increasing copy number of minor variant (C) in IL12A (rs2243140) was significantly associated with a decreased risk of SMA (P = 0.006; risk ratio, 0.52 for carrying one copy of allele C and 0.28 for two copies). Individuals possessing two copies of a rare variant (C) in IL12RB1 (rs429774) also appeared to be strongly protective against SMA (P = 0.00005; risk ratio, 0.18). In addition, children homozygous for another rare allele (T) in IL12A (rs22431348) were associated with reduced risk of severe anaemia (SA) (P = 0.004; risk ratio, 0.69) and of severe anaemia with any parasitaemia (SAP) (P = 0.004; risk ratio, 0.66). In contrast, AG genotype for another variant in IL12RB1 (rs383483) was associated with susceptibility to high-density parasitaemia (HDP) (P = 0.003; risk ratio, 1.21). This study has shown strong associations between polymorphisms in the genes of IL12A and IL12RB1 and protection from SMA in Kenyan children, suggesting that human genetic variants of IL12 related genes may significantly contribute to the development of anaemia in malaria patients.

The association of eight potentially functional polymorphisms in five adrenergic receptor-encoding genes with myocardial infarction risk in Han Chinese.

PubMed

Xia, Kun; Ding, Rongjing; Zhang, Zhiyong; Li, Weiming; Shang, Xiaoming; Yang, Xinchun; Wang, Lefeng; Zhang, Qi

2017-08-15

Adrenergic receptors play a key role in activating the sympathetic nervous system, which often accompanies with the development of myocardial infarction (MI). Here, we aimed to test the association of eight potentially functional polymorphisms in five adrenergic receptor-encoding genes with MI risk. Genotypes were available for 717 MI patients and 612 controls. There were no detectable deviations from the Hardy-Weinberg equilibrium for all study polymorphisms. Allele frequencies differed remarkably for ADRA2B D/I (P<0.001), ADRB1 Ser49Gly (P=0.002), ADRB2 Gln27Glu (P=0.005), and ADRB3 Trp64Arg (P<0.001) polymorphisms, even after the Bonferroni correction. Systolic blood pressure was significantly lower in ADRA2B II genotype carriers than in the DD genotype carriers (P=0.006), while plasma high-density lipoprotein cholesterol was significantly higher in patients carrying ADRA2B I allele and ADRB1 49Ser allele than in patients with the DD genotype and 49Gly/49Gly genotype, respectively (P=0.018 and 0.033). Overall best interaction model consisted of ADRA2B D/I, ADRB1 Ser49Gly, dyslipidemia and hypertension, with the highest testing accuracy of 0.627 and the maximal 10-fold cross-validation consistency (P=0.017). Finally, a nomogram was depicted based on four significant polymorphisms and metabolic risk factors, and it had a better predictive utility and was internally validated with a discrimination C-index of 0.723 (P<0.001). Altogether, we identified two polymorphisms, ADRA2B D/I and ADRB1 Ser49Arg, which not only altered genetic susceptibility to MI, but also impacted on blood pressure and plasma lipid changes, and their combination with metabolic risk factors constituted the overall best interaction model. Copyright © 2017. Published by Elsevier B.V.

Various pharmacogenetic aspects of antiepileptic drug therapy: a review.

PubMed

Mann, Michael W; Pons, Gerard

2007-01-01

Pharmacogenetics concerns the influence of an individual's genetic background on the pharmacokinetics and pharmacodynamics of xenobiotics. Much of the pharmacogenetic data in the field of epilepsy deals with the pharmacokinetics of antiepileptic drugs (AEDs). In particular, two polymorphisms of cytochrome P450 2C9 are known to slow down the metabolism of phenytoin to a degree that increases the risk of the neurotoxic adverse effects of this drug among carriers of these polymorphisms. A significant number of patients with epilepsy do not respond to AEDs and such pharmacoresistance is a major, largely unsolved, problem that is likely to be multifactorial in nature. In this regard, genetic factors may influence transmembrane drug transporter proteins, thereby modifying the intracerebral penetration of AEDs. Monogenic idiopathic epilepsies are rare and frequently associated with ion channel mutations; however, to date, a consistent relationship between changes in channel properties and clinical phenotype has not been established nor has any association between genotype and response to specific treatment options. Polymorphisms of drug targets may represent another genetic facet in epilepsy: a recent study demonstrated for the first time a polymorphism of a drug target (the alpha-subunit of a voltage-gated sodium channel) associated in clinical practice with differing response to two classic AEDs. Adverse drug reactions and teratogenicity of AEDs remain a major concern. Whole-genome single nucleotide polymorphism profiling might in the future help to determine genetic predisposing factors for adverse drug reactions. Recently, in Han Chinese treated with carbamazepine and presenting with Stevens-Johnson syndrome, a strong association was found with HLA B*1502. If genetically targeted drug development becomes more affordable/cost efficient in the near future, the development of new drugs for relatively rare diseases could become economically viable for the pharmaceutical industry. The synergy of lower trial costs and efficacy-based prescribing may reduce the cost of medical treatment for a particular disease. This hypothetical advantage of the practical use of pharmacogenetics is, however, counterbalanced by several possible dangers, including illicit data mining and the development of a human 'genetic underclass' with the risk of exclusion from, for example employment or health insurance, because of an 'unfavourable' genetic profile.

The Functional Role of eL19 and eB12 Intersubunit Bridge in the Eukaryotic Ribosome.

PubMed

Kisly, Ivan; Gulay, Suna P; Mäeorg, Uno; Dinman, Jonathan D; Remme, Jaanus; Tamm, Tiina

2016-05-22

During translation, the two eukaryotic ribosomal subunits remain associated through 17 intersubunit bridges, five of which are eukaryote specific. These are mainly localized to the peripheral regions and are believed to stabilize the structure of the ribosome. The functional importance of these bridges remains largely unknown. Here, the essentiality of the eukaryote-specific bridge eB12 has been investigated. The main component of this bridge is ribosomal protein eL19 that is composed of an N-terminal globular domain, a middle region, and a long C-terminal α-helix. The analysis of deletion mutants demonstrated that the globular domain and middle region of eL19 are essential for cell viability, most likely functioning in ribosome assembly. The eB12 bridge, formed by contacts between the C-terminal α-helix of eL19 and 18S rRNA in concert with additional stabilizing interactions involving either eS7 or uS17, is dispensable for viability. Nevertheless, eL19 mutants impaired in eB12 bridge formation displayed slow growth phenotypes, altered sensitivity/resistance to translational inhibitors, and enhanced hyperosmotic stress tolerance. Biochemical analyses determined that the eB12 bridge contributes to the stability of ribosome subunit interactions in vitro. 60S subunits containing eL19 variants defective in eB12 bridge formation failed to form 80S ribosomes regardless of Mg(2+) concentration. The reassociation of 40S and mutant 60S subunits was markedly improved in the presence of deacetylated tRNA, emphasizing the importance of tRNAs during the subunit association. We propose that the eB12 bridge plays an important role in subunit joining and in optimizing ribosome functionality. Copyright © 2016 Elsevier Ltd. All rights reserved.

Biochemical and genetic characterization of the Enterococcus faecalis oxaloacetate decarboxylase complex.

PubMed

Repizo, Guillermo D; Blancato, Víctor S; Mortera, Pablo; Lolkema, Juke S; Magni, Christian

2013-05-01

Enterococcus faecalis encodes a biotin-dependent oxaloacetate decarboxylase (OAD), which is constituted by four subunits: E. faecalis carboxyltransferase subunit OadA (termed Ef-A), membrane pump Ef-B, biotin acceptor protein Ef-D, and the novel subunit Ef-H. Our results show that in E. faecalis, subunits Ef-A, Ef-D, and Ef-H form a cytoplasmic soluble complex (termed Ef-AHD) which is also associated with the membrane. In order to characterize the role of the novel Ef-H subunit, coexpression of oad genes was performed in Escherichia coli, showing that this subunit is vital for Ef-A and Ef-D interaction. Diminished growth of the oadA and oadD single deletion mutants in citrate-supplemented medium indicated that the activity of the complex is essential for citrate utilization. Remarkably, the oadB-deficient strain was still capable of growing to wild-type levels but with a delay during the citrate-consuming phase, suggesting that the soluble Ef-AHD complex is functional in E. faecalis. These results suggest that the Ef-AHD complex is active in its soluble form, and that it is capable of interacting in a dynamic way with the membrane-bound Ef-B subunit to achieve its maximal alkalinization capacity during citrate fermentation.

Overexpression of PP2A-C5 that encodes the catalytic subunit 5 of protein phosphatase 2A in Arabidopsis confers better root and shoot development under salt conditions

USDA-ARS?s Scientific Manuscript database

Protein phosphatase 2A (PP2A) is an enzyme consisting of three subunits: a scaffolding A subunit, a regulatory B subunit and a catalytic C subunit. PP2As were shown to play diverse roles in eukaryotes. In this study, the function of the Arabidopsis PP2A-C5 gene that encodes the catalytic subunit 5 o...

GATA3 rs3824662 gene polymorphism as possible risk factor in a cohort of Egyptian patients with pediatric acute lymphoblastic leukemia and its prognostic impact.

PubMed

Mosaad, Youssef M; Elashery, Rasha; Darwish, Ahmad; Sharaf Eldein, Omar A; Barakat, Tarek; Marouf, Samy; Abou El-Khier, Noha T; Youssef, Laila F; Fawzy, Iman M

2017-03-01

To investigate the possible role of GATA3 rs3824662 polymorphism as risk factor for the development of acute lymphoblastic leukemia (ALL) in a cohort of Egyptian children and to evaluate its prognostic role. Typing of GATA3 rs3824662 polymorphism was done using real-time PCR for 116 patients with ALL and 273 healthy controls. The A allele and AA genotype were significantly higher in ALL patients (p = .015 and .016, respectively) especially B-ALL (p = .014 and .01, respectively). The AA genotype was associated with shorter disease free survival (DFS) in univariate (p = .017) and multivariate cox regression analysis (p = .028), increased incidence of relapse (p = .008) and poor prognosis (p = .028) in pediatric ALL. The GATA3 rs3824662 A allele and AA genotype may be risk factors for the development of pediatric ALL especially B-ALL in the studied cohort of Egyptian patients. The AA genotype is associated with shorter DSF, increased incidence of relapse and poor prognosis in pediatric ALL.

Genetic Variation in Glutathione-Related Genes and Body Burden of Methylmercury

PubMed Central

Engström, Karin Schläwicke; Strömberg, Ulf; Lundh, Thomas; Johansson, Ingegerd; Vessby, Bengt; Hallmans, Göran; Skerfving, Staffan; Broberg, Karin

2008-01-01

Background Exposure to toxic methylmercury (MeHg) through fish consumption is a large problem worldwide, and it has led to governmental recommendations of reduced fish consumption and blacklisting of mercury-contaminated fish. The elimination kinetics of MeHg varies greatly among individuals. Knowledge about the reasons for such variation is of importance for improving the risk assessment for MeHg. One possible explanation is hereditary differences in MeHg metabolism. MeHg is eliminated from the body as a glutathione (GSH) conjugate. Objectives We conducted this study to assess the influence of polymorphisms in GSH-synthesizing [glutamyl-cysteine ligase modifier subunit (GCLM-588) and glutamyl-cysteine ligase catalytic subunit (GCLC-129)] or GSH-conjugating [glutathione S-transferase pi 1 (GSTP1–105 and GSTP1–114)] genes on MeHg retention. Methods Based on information obtained from questionnaires, 292 subjects from northern Sweden had a high consumption of fish (lean/fat fish two to three times per week or more). We measured total Hg in erythrocytes (Ery-Hg) and long-chain n-3 polyunsaturated fatty acids in plasma (P-PUFA; an exposure marker for fish intake). Results The GSTP1 genotype modified Ery-Hg; effects were seen for GSTP1–105 and −114 separately, and combining them resulted in stronger effects. We found evidence of effect modification: individuals with zero or one variant allele demonstrated a steeper regression slope for Ery-Hg (p = 0.038) compared with individuals with two or more variant alleles. The GCLM-588 genotype also influenced Ery-Hg (p = 0.035): Individuals with the GCLM-588 TT genotype demonstrated the highest Ery-Hg, but we saw no evidence of effect modification with increasing P-PUFA. Conclusions These results suggest a role of GSH-related polymorphisms in MeHg metabolism. PMID:18560528

Crystallization of isoelectrically homogeneous cholera toxin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spangler, B.D.; Westbrook, E.M.

1989-02-07

Past difficulty in growing good crystals of cholera toxin has prevented the study of the crystal structure of this important protein. The authors have determined that failure of cholera toxin to crystallize well has been due to its heterogeneity. They have now succeeded in overcoming the problem by isolating a single isoelectric variant of this oligomeric protein (one A subunit and five B subunits). Cholera toxin purified by their procedure readily forms large single crystals. The crystal form has been described previously. They have recorded data from native crystals of cholera toxin to 3.0-{angstrom} resolution with our electronic area detectors.more » With these data, they have found the orientation of a 5-fold symmetry axis within these crystals, perpendicular to the screw dyad of the crystal. They are now determining the crystal structure of cholera toxin by a combination of multiple heavy-atom isomorphous replacement and density modification techniques, making use of rotational 5-fold averaging of the B subunits.« less

Correction of xeroderma pigmentosum repair defect by basal transcription factor BTF2 (TFIIH).

PubMed Central

van Vuuren, A J; Vermeulen, W; Ma, L; Weeda, G; Appeldoorn, E; Jaspers, N G; van der Eb, A J; Bootsma, D; Hoeijmakers, J H; Humbert, S

1994-01-01

ERCC3 was initially identified as a gene correcting the nucleotide excision repair (NER) defect of xeroderma pigmentosum complementation group B (XP-B). The recent finding that its gene product is identical to the p89 subunit of basal transcription factor BTF2(TFIIH), opened the possibility that it is not directly involved in NER but that it regulates the transcription of one or more NER genes. Using an in vivo microinjection repair assay and an in vitro NER system based on cell-free extracts we demonstrate that ERCC3 in BTF2 is directly implicated in excision repair. Antibody depletion experiments support the idea that the p62 BTF2 subunit and perhaps the entire transcription factor function in NER. Microinjection experiments suggest that exogenous ERCC3 can exchange with ERCC3 subunits in the complex. Expression of a dominant negative K436-->R ERCC3 mutant, expected to have lost all helicase activity, completely abrogates NER and transcription and concomitantly induces a dramatic chromatin collapse. These findings establish the role of ERCC3 and probably the entire BTF2 complex in transcription in vivo which was hitherto only demonstrated in vitro. The results strongly suggest that transcription itself is a critical component for maintenance of chromatin structure. The remarkable dual role of ERCC3 in NER and transcription provides a clue in understanding the complex clinical features of some inherited repair syndromes. Images PMID:8157004

Low level of efavirenz in HIV-1-infected Thai adults is associated with the CYP2B6 polymorphism.

PubMed

Sukasem, C; Manosuthi, W; Koomdee, N; Santon, S; Jantararoungtong, T; Prommas, S; Chamnanphol, M; Puangpetch, A; Sungkanuparph, S

2014-06-01

Human immunodeficiency virus type 1 (HIV-1) infections with a plasma efavirenz concentration of <1,000 ng/mL appear to have a high risk for the emergence of drug resistance. In the present study, we assessed the influence of the CYP2B6 polymorphism on the plasma efavirenz level. CYP2B6 T18492C (rs2279345) in 149 HIV-infected Thai adults were genotyped. Plasma efavirenz concentrations 12 h after dosing were measured using a validated high-performance liquid chromatography. The relationship between the plasma efavirenz level and the CYP2B6 T18492C polymorphism were analysed. Among the 149 patients, the frequency of T18492C heterozygous (T/C) and homozygous mutant (C/C) was 38.26 % (n = 57) and 6.04 % (n = 9), respectively. In the entire cohort, the median efavirenz plasma concentration was 2,410 ng/mL [interquartile range (IQR) 1,460-4,120 ng/mL]. The plasma efavirenz concentration for patients with 18492CC (1,200 ng/mL, IQR 1,050-1,990 ng/mL) or 18492TC (1,900 ng/mL, IQR 1,320-2,510 ng/mL) genotypes were significantly lower than those with homozygous wild type (3,380 ng/mL, IQR 2,040-5,660 ng/mL), P-value < 0.001. The CYP2B6 T18492C polymorphism was significantly associated with lower efavirenz concentrations compared to those with homozygous wild type in HIV-1 infections. The genetic polymorphism CYP2B6 T18492C may be useful for the optimised efavirenz dose. Further studies in the clinical setting will need to be conducted before such an approach can be recommended for widespread use.

Aluminium induced oxidative stress results in decreased mitochondrial biogenesis via modulation of PGC-1α expression.

PubMed

Sharma, Deep Raj; Sunkaria, Aditya; Wani, Willayat Yousuf; Sharma, Reeta Kumari; Kandimalla, Ramesh J L; Bal, Amanjit; Gill, Kiran Dip

2013-12-01

The present investigation was carried out to elucidate a possible molecular mechanism related to the effects of aluminium-induced oxidative stress on various mitochondrial respiratory complex subunits with special emphasis on the role of Peroxisome proliferator activated receptor gamma co-activator 1α (PGC-1α) and its downstream targets i.e. Nuclear respiratory factor-1(NRF-1), Nuclear respiratory factor-2(NRF-2) and Mitochondrial transcription factor A (Tfam) in mitochondrial biogenesis. Aluminium lactate (10mg/kgb.wt./day) was administered intragastrically to rats for 12 weeks. After 12 weeks of exposure, we found an increase in ROS levels, mitochondrial DNA oxidation and decrease in citrate synthase activity in the Hippocampus (HC) and Corpus striatum (CS) regions of rat brain. On the other hand, there was a decrease in the mRNA levels of the mitochondrial encoded subunits-NADH dehydrogenase (ND) subunits i.e. ND1, ND2, ND3, Cytochrome b (Cytb), Cytochrome oxidase (COX) subunits i.e. COX1, COX3, ATP synthase (ATPase) subunit 6 along with reduced expression of nuclear encoded subunits COX4, COX5A, COX5B of Electron transport chain (ETC). Besides, a decrease in mitochondrial DNA copy number and mitochondrial content in both regions of rat brain was observed. The PGC-1α was down-regulated in aluminium treated rats along with NRF-1, NRF-2 and Tfam, which act downstream from PGC-1α in aluminium treated rats. Electron microscopy results revealed a significant increase in the mitochondrial swelling, loss of cristae, chromatin condensation and decreases in mitochondrial number in case of aluminium treated rats as compared to control. So, PGC-1α seems to be a potent target for aluminium neurotoxicity, which makes it an almost ideal target to control or limit the damage that has been associated with the defective mitochondrial function seen in neurodegenerative diseases. © 2013.

Echinococcus granulosus: Evidence of a heterodimeric glutathione transferase built up by phylogenetically distant subunits.

PubMed

Arbildi, Paula; La-Rocca, Silvana; Lopez, Veronica; Da-Costa, Natalia; Fernandez, Veronica

2017-01-01

In the cestode parasite Echinococcus granulosus, three phylogenetically distant cytosolic glutathione transferases (GSTs) (EgGST1, 2 and 3) were identified. Interestingly, the C-terminal domains of EgGST3 and EgGST2 but not EgGST1, exhibit all amino acids involved in Sigma-class GST dimerization. Here, we provide evidence indicating that EgGST2 and EgGST3 naturally form a heterodimeric structure (EgGST2-3), and also we report the enzymatic activity of the recombinant heterodimer. EgGST2-3 might display novel properties able to influence the infection establishment. This is the first report of a stable heterodimeric GST built up by phylogenetically distant subunits. Copyright © 2016 Elsevier B.V. All rights reserved.

High resolution melting curve assay for detecting rs12979860 IL28B polymorphisms involved in response of Iranian patients to chronic hepatitis C treatment.

PubMed

Fateh, Abolfazl; Aghasadeghi, Mohammad Reza; Keyvani, Hossein; Mollaie, Hamid Reza; Yari, Shamsi; Hadizade Tasbiti, Ali Reza; Ghazanfari, Morteza; Monavari, Seyed Hamid Reza

2015-01-01

A recent genome-wide association study (GWAS) on patients with chronic hepatitis C (CHC) treated with peginterferon and ribavirin (pegIFN-α/RBV) identified a single nucleotide polymorphism (SNP) on chromosome 19 (rs12979860) which was strongly associated with a sustained virological response (SVR). The aim of this study was twofold: to study the relationship between IL28B rs12979860 and sustained virological response (SVR) to pegIFN-α/RVB therapy among CHC patients and to detect the rs12979860 polymorphism by high resolution melting curve (HRM) assay as a simple, fast, sensitive, and inexpensive method. The study examined outcomes in 100 patients with chronic hepatitis C in 2 provinces of Iran from December 2011 to June 2013. Two methods were applied to detect IL28B polymorphisms: PCR-sequencing as a gold standard method and HRM as a simple, fast, sensitive, and inexpensive method. The frequencies of IL28B rs12979860 CC, CT, and TT alleles in chronic hepatitis C genotype 1a patients were 10% (10/100), 35% (35/100), and 6% (6/100) and in genotype 3a were 13% (13/100), 31% (31/100), and 5% (5/100), respectively. In genotype 3a infected patients, rs12979860 (CC and CT alleles) and in genotype 1a infected patients (CC allele) were significantly associated with a sustained virological response (SVR). The SVR rates for CC, CT and TT (IL28B rs12979860) were 18%, 34% and 4%, respectively. Multiple logistic regression analysis identified two independent factors that were significantly associated with SVR: IL-28B genotype (rs 12979860 CC vs TT and CT; odds ratio [ORs], 7.86 and 4.084, respectively), and HCV subtype 1a (OR, 7.46). In the present study, an association between SVR rates and IL28B polymorphisms was observed. The HRM assay described herein is rapid, inexpensive, sensitive and accurate for detecting rs12979860 alleles in CHC patients. This method can be readily adopted by any molecular diagnostic laboratory with HRM capability and will be clinically beneficial in predicting treatment response in HCV genotype 1 and 3 infected patients. In addition, it was demonstrated that CC and CT alleles in HCV-3a and the CC allele in HCV-1a were significantly associated with response to pegIFN-α/RBV treatment. The present results may help identify subjects for whom the therapy might be successful.

Chemically related 4,5-linked aminoglycoside antibiotics drive subunit rotation in opposite directions

PubMed Central

Wasserman, Michael R.; Pulk, Arto; Zhou, Zhou; Altman, Roger B.; Zinder, John C.; Green, Keith D.; Garneau-Tsodikova, Sylvie; Doudna Cate, Jamie H.; Blanchard, Scott C.

2015-01-01

Dynamic remodelling of intersubunit bridge B2, a conserved RNA domain of the bacterial ribosome connecting helices 44 (h44) and 69 (H69) of the small and large subunit, respectively, impacts translation by controlling intersubunit rotation. Here we show that aminoglycosides chemically related to neomycin—paromomycin, ribostamycin and neamine—each bind to sites within h44 and H69 to perturb bridge B2 and affect subunit rotation. Neomycin and paromomycin, which only differ by their ring-I 6′-polar group, drive subunit rotation in opposite directions. This suggests that their distinct actions hinge on the 6′-substituent and the drug's net positive charge. By solving the crystal structure of the paromomycin–ribosome complex, we observe specific contacts between the apical tip of H69 and the 6′-hydroxyl on paromomycin from within the drug's canonical h44-binding site. These results indicate that aminoglycoside actions must be framed in the context of bridge B2 and their regulation of subunit rotation. PMID:26224058

Functional ion channels in human pulmonary artery smooth muscle cells: Voltage-dependent cation channels

PubMed Central

Firth, Amy L.; Remillard, Carmelle V.; Platoshyn, Oleksandr; Fantozzi, Ivana; Ko, Eun A.; Yuan, Jason X.-J.

2011-01-01

The activity of voltage-gated ion channels is critical for the maintenance of cellular membrane potential and generation of action potentials. In turn, membrane potential regulates cellular ion homeostasis, triggering the opening and closing of ion channels in the plasma membrane and, thus, enabling ion transport across the membrane. Such transmembrane ion fluxes are important for excitation–contraction coupling in pulmonary artery smooth muscle cells (PASMC). Families of voltage-dependent cation channels known to be present in PASMC include voltage-gated K+ (Kv) channels, voltage-dependent Ca2+-activated K+ (Kca) channels, L- and T- type voltage-dependent Ca2+ channels, voltage-gated Na+ channels and voltage-gated proton channels. When cells are dialyzed with Ca2+-free K+- solutions, depolarization elicits four components of 4-aminopyridine (4-AP)-sensitive Kvcurrents based on the kinetics of current activation and inactivation. In cell-attached membrane patches, depolarization elicits a wide range of single-channel K+ currents, with conductances ranging between 6 and 290 pS. Macroscopic 4-AP-sensitive Kv currents and iberiotoxin-sensitive Kca currents are also observed. Transcripts of (a) two Na+ channel α-subunit genes (SCN5A and SCN6A), (b) six Ca2+ channel α–subunit genes (α1A, α1B, α1X, α1D, α1Eand α1G) and many regulatory subunits (α2δ1, β1-4, and γ6), (c) 22 Kv channel α–subunit genes (Kv1.1 - Kv1.7, Kv1.10, Kv2.1, Kv3.1, Kv3.3, Kv3.4, Kv4.1, Kv4.2, Kv5.1, Kv 6.1-Kv6.3, Kv9.1, Kv9.3, Kv10.1 and Kv11.1) and three Kv channel β-subunit genes (Kvβ1-3) and (d) four Kca channel α–subunit genes (Sloα1 and SK2-SK4) and four Kca channel β-subunit genes (Kcaβ1-4) have been detected in PASMC. Tetrodotoxin-sensitive and rapidly inactivating Na+ currents have been recorded with properties similar to those in cardiac myocytes. In the presence of 20 mM external Ca2+, membrane depolarization from a holding potential of -100 mV elicits a rapidly inactivating T-type Ca2+ current, while depolarization from a holding potential of -70 mV elicits a slowly inactivating dihydropyridine-sensitive L-type Ca2+ current. This review will focus on describing the electrophysiological properties and molecular identities of these voltage-dependent cation channels in PASMC and their contribution to the regulation of pulmonary vascular function and its potential role in the pathogenesis of pulmonary vascular disease. PMID:21927714

Two distinctive β subunits are separately involved in two binding sites of imidacloprid with different affinities in Locusta migratoria manilensis.

PubMed

Bao, Haibo; Liu, Yang; Zhang, Yixi; Liu, Zewen

2017-08-01

Due to great diversity of nicotinic acetylcholine receptor (nAChR) subtypes in insects, one β subunit may be contained in numerous nAChR subtypes. In the locust Locusta migratoria, a model insect species with agricultural importance, the third β subunits (Locβ3) was identified in this study, which reveals at least three β subunits in this insect species. Imidacloprid was found to bind nAChRs in L. migratoria central nervous system at two sites with different affinities, with K d values of 0.16 and 10.31nM. The specific antisera (L1-1, L2-1 and L3-1) were raised against fusion proteins at the large cytoplasmic loop of Locβ1, Locβ2 and Locβ3 respectively. Specific immunodepletion of Locβ1 with antiserum L1-1 resulted in the selective loss of the low affinity binding site for imidacloprid, whereas the immunodepletion of Locβ3 with L3-1 caused the selective loss of the high affinity site. Dual immunodepletion with L1-1 and L3-1 could completely abolish imidacloprid binding. In contrast, the immunodepletion of Locβ2 had no significant effect on the specific [ 3 H]imidacloprid binding. Taken together, these data indicated that Locβ1 and Locβ3 were respectively contained in the low- and high-affinity binding sites for imidacloprid in L. migratoria, which is different to the previous finding in Nilaparvata lugens that Nlβ1 was in two binding sites for imidacloprid. The involvement of two β subunits separately in two binding sites may decrease the risk of imidacloprid resistance due to putative point mutations in β subunits in L. migratoria. Copyright © 2017 Elsevier B.V. All rights reserved.

Substitutions at the opening of the Rubisco central solvent channel affect holoenzyme stability and CO2/O 2 specificity but not activation by Rubisco activase.

PubMed

Esquivel, M Gloria; Genkov, Todor; Nogueira, Ana S; Salvucci, Michael E; Spreitzer, Robert J

2013-12-01

Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) catalyzes the initial step of carbon metabolism in photosynthesis. The holoenzyme comprises eight large subunits, arranged as a tetramer of dimers around a central solvent channel that defines a fourfold axis of symmetry, and eight small subunits, arranged as two tetramers at the poles of the axis. The phylogenetically divergent small-subunit loops between β-strands A and B form the entrance to the solvent channel. In the green alga Chlamydomonas reinhardtii, Ile-58 from each of the four small-subunit βA-βB loops defines the minimal diameter of the channel opening. To understand the role of the central solvent channel in Rubisco function, directed mutagenesis and transformation of Chlamydomonas were employed to replace Ile-58 with Ala, Lys, Glu, Trp, or three Trp residues (I58W3) to close the entrance to the channel. The I58E, I58K, and I58W substitutions caused only small decreases in photosynthetic growth at 25 and 35 °C, whereas I58W3 had a substantial effect at both temperatures. The mutant enzymes had decreased carboxylation rates, but the I58W3 enzyme had decreases in both carboxylation and CO2/O2 specificity. The I58E, I58W, and I58W3 enzymes were inactivated at lower temperatures than wild-type Rubisco, and were degraded at slower rates under oxidative stress. However, these mutant enzymes were activated by Rubisco activase at normal rates, indicating that the structural transition required for carboxylation is not affected by altering the solvent channel opening. Structural dynamics alone may not be responsible for these distant effects on the Rubisco active site.

Measuring Positive Cooperativity Using the Direct ESI-MS Assay. Cholera Toxin B Subunit Homopentamer Binding to GM1 Pentasaccharide

NASA Astrophysics Data System (ADS)

Lin, Hong; Kitova, Elena N.; Klassen, John S.

2014-01-01

Direct electrospray ionization mass spectrometry (ESI-MS) assay was used to investigate the stepwise binding of the GM1 pentasaccharide β- D-Gal p-(1→3)-β-D-Gal pNAc-(1→4)[α-D-Neu5Ac-(2→3)]-β- D-Gal p-(1→4)-β-D-Glc p (GM1os) to the cholera toxin B subunit homopentamer (CTB5) and to establish conclusively whether GM1os binding is cooperative. Apparent association constants were measured for the stepwise addition of one to five GM1os to CTB5 at pH 6.9 and 22 °C. The intrinsic association constant, which was established from the apparent association constant for the addition of a single GM1os to CTB5, was found to be (3.2 ± 0.2) × 106 M-1. This is in reasonable agreement with the reported value of (6.4 ± 0.3) × 106 M-1, which was measured at pH 7.4 and 25 °C using isothermal titration calorimetry (ITC). Analysis of the apparent association constants provides direct and unambiguous evidence that GM1os binding exhibits small positive cooperativity. Binding was found to be sensitive to the number of ligand-bound nearest neighbor subunits, with the affinities enhanced by a factor of 1.7 and 2.9 when binding occurs next to one or two ligand-bound subunits, respectively. These findings, which provide quantitative support for the binding model proposed by Homans and coworkers [14], highlight the unique strengths of the direct ESI-MS assay for measuring cooperative ligand binding.

The Aged Microenvironment Influences Prostate Carcinogenesis

DTIC Science & Technology

2009-12-01

Pcdhb4 protocadherin beta 4 NM_053129 -2.3 BC068157 cDNA sequence BC068157 NM_207203 -2.3 Bub1 budding uninhibited by benzimidazoles 1 NM_009772...protein phosphatase 2, regulatory subunit B NM_028392 -2.1 Bub3 budding uninhibited by benzimidazoles 3 AK083742 -2.1 Kif4 kinesin family member 4

The association of folate pathway and DNA repair polymorphisms with susceptibility to childhood acute lymphoblastic leukemia.

PubMed

Goričar, Katja; Erčulj, Nina; Faganel Kotnik, Barbara; Debeljak, Maruša; Hovnik, Tinka; Jazbec, Janez; Dolžan, Vita

2015-05-15

Genetic factors may play an important role in susceptibility to childhood acute lymphoblastic leukemia (ALL). The aim of our study was to evaluate the associations of genetic polymorphisms in folate pathway and DNA repair genes with susceptibility to ALL. In total, 121 children with ALL and 184 unrelated healthy controls of Slovenian origin were genotyped for 14 polymorphisms in seven genes of folate pathway, base excision repair and homologous recombination repair (TYMS, MTHFR, OGG1, XRCC1, NBN, RAD51, and XRCC3). In addition, the exon 6 of NBN was screened for the presence of mutations using denaturing high performance liquid chromatography. Twelve polymorphisms were in Hardy-Weinberg equilibrium in controls and their genotype frequencies were in agreement with those reported in other Caucasian populations. Among the investigated polymorphisms and mutations, NBN Glu185Gln significantly decreased susceptibility to B-cell ALL (p=0.037), while TYMS 3R allele decreased susceptibility to T-cell ALL (p=0.011). Moreover, significantly decreased susceptibility to ALL was observed for MTHFR TA (p=0.030) and RAD51 GTT haplotypes (p=0.016). Susceptibility to ALL increased with the increasing number of risk alleles (ptrend=0.007). We also observed significant influence of hOGG-RAD51 and NBN-RAD51 interactions on susceptibility to ALL. Our results suggest that combination of several polymorphisms in DNA repair and folate pathways may significantly affect susceptibility to childhood ALL. Copyright © 2015 Elsevier B.V. All rights reserved.

APOC3 Promoter Polymorphisms C-482T and T-455C Are Associated with the Metabolic Syndrome1

PubMed Central

Miller, Michael; Rhyne, Jeffrey; Chen, Hegang; Beach, Valerie; Ericson, Richard; Luthra, Kalpana; Dwivedi, Manjari; Misra, Anoop

2007-01-01

Background Despite the growing epidemic of the metabolic syndrome (MetS), few studies have evaluated genetic polymorphisms associated with the MetS phenotype. One candidate, APOC3, modulates lipid and lipoprotein metabolism and the promoter polymorphisms C-482T/T-455C are associated with loss of insulin downregulation. Methods One hundred twenty two consecutive MetS cases were matched by age, sex and race in a 1:1 case-control design to evaluate the prevalence of common polymorphisms in the following candidate genes: APOC3, APOE, B3AR, FABP2, GNB3, LPL, and PPARα and PPARγ. Results Compared to controls, MetS subjects exhibited a greater prevalence of APOC3 promoter polymorphisms. Specifically, the frequency of the variant C-482T and T-455C alleles was 70.5 and 81.9% of cases compared to 43.4 and 54.1% in controls, respectively ( p <0.0001). Overall, APOC3 promoter variants were associated with a greater likelihood of MetS compared to wild type [C-482T (OR: 4.3; 95% CI: 2.2, 8.6 [p <0.0001]), T-455C (OR: 3.6; 95% CI: 2.0, 6.7 [p <0.0001])]. No material differences were identified between the other genetic variants tested and prevalence of MetS. Conclusions These data, therefore, suggest that the APOC3 promoter polymorphisms C-482T and T-455C are associated with the MetS. PMID:17416293

APOC3 promoter polymorphisms C-482T and T-455C are associated with the metabolic syndrome.

PubMed

Miller, Michael; Rhyne, Jeffrey; Chen, Hegang; Beach, Valerie; Ericson, Richard; Luthra, Kalpana; Dwivedi, Manjari; Misra, Anoop

2007-05-01

Despite the growing epidemic of the metabolic syndrome (MetS), few studies have evaluated genetic polymorphisms associated with the MetS phenotype. One candidate, APOC3, modulates lipid and lipoprotein metabolism and the promoter polymorphisms C-482T/T-455C are associated with loss of insulin downregulation. One hundred twenty two consecutive MetS cases were matched by age, sex and race in a 1:1 case-control design to evaluate the prevalence of common polymorphisms in the following candidate genes: APOC3, APOE, B3AR, FABP2, GNB3, LPL, and PPARalpha and PPARgamma. Compared to controls, MetS subjects exhibited a greater prevalence of APOC3 promoter polymorphisms. Specifically, the frequency of the variant C-482T and T-455C alleles was 70.5 and 81.9% of cases compared to 43.4 and 54.1% in controls, respectively (p <0.0001). Overall, APOC3 promoter variants were associated with a greater likelihood of MetS compared to wild type [C-482T (OR: 4.3; 95% CI: 2.2, 8.6 [p <0.0001]), T-455C (OR: 3.6; 95% CI: 2.0, 6.7 [p <0.0001])]. No material differences were identified between the other genetic variants tested and prevalence of MetS. These data, therefore, suggest that the APOC3 promoter polymorphisms C-482T and T-455C are associated with the MetS.

The crystal structures of native hydroquinone 1,2-dioxygenase from Sphingomonas sp. TTNP3 and of substrate and inhibitor complexes.

PubMed

Ferraroni, Marta; Da Vela, Stefano; Kolvenbach, Boris A; Corvini, Philippe F X; Scozzafava, Andrea

2017-05-01

The crystal structure of hydroquinone 1,2-dioxygenase, a Fe(II) ring cleaving dioxygenase from Sphingomonas sp. strain TTNP3, which oxidizes a wide range of hydroquinones to the corresponding 4-hydroxymuconic semialdehydes, has been solved by Molecular Replacement, using the coordinates of PnpCD from Pseudomonas sp. strain WBC-3. The enzyme is a heterotetramer, constituted of two subunits α and two β of 19 and 38kDa, respectively. Both the two subunits fold as a cupin, but that of the small α subunit lacks a competent metal binding pocket. Two tetramers are present in the asymmetric unit. Each of the four β subunits in the asymmetric unit binds one Fe(II) ion. The iron ion in each β subunit is coordinated to three protein residues, His258, Glu264, and His305 and a water molecule. The crystal structures of the complexes with the substrate methylhydroquinone, obtained under anaerobic conditions, and with the inhibitors 4-hydroxybenzoate and 4-nitrophenol were also solved. The structures of the native enzyme and of the complexes present significant differences in the active site region compared to PnpCD, the other hydroquinone 1,2-dioxygenase of known structure, and in particular they show a different coordination at the metal center. Copyright © 2017 Elsevier B.V. All rights reserved.

eNOS gene T786C, G894T and 4a4b polymorphisms and male infertility susceptibility: a meta-analysis.

PubMed

Chang, J; Pan, F; Tang, Q; Wu, W; Chen, M; Lu, C; Ding, H; Hu, L; Chen, D; Xia, Y; Wang, X

2017-05-01

The association between polymorphism of eNOS and male infertility in several studies was controversial. To explore a more precise estimation of the association, a meta-analysis of eight case-control studies, including 1,968 cases and 1,539 controls, were selected. The meta-analysis was conducted by calculating the pooled odds ratio (OR) with a 95% confidence interval (95% CI). Overall, the association between T786C and risk of male infertility was obvious (TC vs. TT: OR, 1.20; 95% CI, 1.01-1.42; CC vs. TT: OR, 3.37; 95% CI, 1.65-6.87; TC/CC vs. TT: OR, 1.47; 95% CI, 1.25-1.73; CC vs. OR, 3.18; 95% CI, 1.54-6.56; TC vs. TT: OR, 1.65; 95% CI, 1.27-2.03). However, no overall association was observed between the other two polymorphisms of eNOS (G894T and 4a4b) and male infertility. Stratified analysis showed that significantly strong association between T786C polymorphism and semen quality was present in all three types of male infertility (azoospermia, oligozoospermia and asthenozoospermia). In the subgroup analysis based on ethnicity, both T786C and 4a4b could influence the risk of male infertility in Asian and Caucasian. Further studies of polymorphisms of eNOS with their biological functions are needed to understand the role in the development of male infertility. © 2016 Blackwell Verlag GmbH.

Association between the rs1143634 polymorphism in interleukin-1B and chronic periodontitis: Results from a meta-analysis composed by 54 case/control studies.

PubMed

da Silva, Felipe Rodolfo Pereira; Vasconcelos, Any Carolina Cardoso Guimarães; de Carvalho França, Luiz Felipe; Di Lenardo, David; Nascimento, Hélio Mateus Silva; Vasconcelos, Daniel Fernando Pereira

2018-08-20

Several factors are involved in the periodontitis with host response through cytokines and as well as with influence of polymorphisms in cytokine genes, however the results remained contradictory. This study aimed at evaluating the rs1143634 polymorphism in interleukin-1B gene, a cytokine gene, and the risk of chronic periodontitis with conducting a meta-analysis focusing in ethnicity. A review in literature was performed in several databases to studies published before June 2017. Data extraction was performed by two calibrated investigators and the calculations of the meta-analysis were obtained through Review Manager version 5.2 statistical software with Odds Ratio (OR) calculation and Funnel plot (P < 0.05) to heterogeneity and the Comprehensive Meta-analysis version 3.3.070 to assessment publication bias by Egger's and Begg's tests. In overall, 54 case/control studies composed the meta-analysis. T allele was significantly associated with patients case (OR = 1.35, 95% CI: 1.24, 1.48, P < 0.00001) in the overall analysis. The stratified evaluation showed the rs1143634 polymorphism had significant association with disease in Caucasian, Asian and mixed population was excepted in African ethnicity (P > 0.05). No publication bias was found in allelic evaluation. This meta-analysis in 9376 participants with 54 case/control studies revealed the rs1143634 polymorphism was associated with elevated risk of chronic periodontitis in overall analysis as well as Caucasian and Asian ethnicities and Mixed population. Copyright © 2018 Elsevier B.V. All rights reserved.

Association of genetic variations with pharmacokinetics and lipid-lowering response to atorvastatin in healthy Korean subjects.

PubMed

Woo, Hye In; Kim, Suk Ran; Huh, Wooseong; Ko, Jae-Wook; Lee, Soo-Youn

2017-01-01

Statins are effective agents in the primary and secondary prevention of cardiovascular disease, but treatment response to statins varies among individuals. We analyzed multiple genetic polymorphisms and assessed pharmacokinetic and lipid-lowering responses after atorvastatin 80 mg treatment in healthy Korean individuals. Atorvastatin 80 mg was given to 50 healthy Korean male volunteers. Blood samples were collected to measure plasma atorvastatin and lipid concentrations up to 48 hours after atorvastatin administration. Subjects were genotyped for 1,936 drug metabolism and transporter genetic polymorphisms using the Affymetrix DMET plus array. The pharmacokinetics and lipid-lowering effect of atorvastatin showed remarkable interindividual variation. Three polymorphisms in the SLCO1B1 , SLCO1B3 , and ABCC2 genes were associated with either the maximum concentration (C max ) of atorvastatin or changes in total cholesterol or low-density lipoprotein cholesterol (LDL-C). Minor homozygotes (76.5 ng/mL) of SLCO1B1 c.-910G>A showed higher C max than heterozygotes (34.0 ng/mL) and major homozygotes (33.5 ng/mL, false discovery rate P =0.040). C max and the area under the plasma concentration curve from hour 0 to infinity (AUC ∞ ) were higher in carriers of the SLCO1B1 *17 haplotype that included c.-910G>A than in noncarriers (46.1 vs 32.8 ng/mL for C max ; 221.5 vs 154.2 ng/mL for AUC ∞ ). SLCO1B3 c.334G>T homozygotes (63.0 ng/mL) also showed higher C max than heterozygotes (34.7 ng/mL) and major homozygotes (31.4 ng/mL, FDR P =0.037). A nonsynonymous ABCC2 c.1249G>A was associated with small total cholesterol and LDL-C responses (0.23% and -0.70% for G/A vs -11.9% and -17.4% for G/G). The C max tended to increase according to the increase in the number of minor allele of SLCO1B1 c. -910G>A and SLCO1B3 c.334G>T. Genetic polymorphisms in transporter genes, including SLCO1B1 , SLCO1B3 , and ABCC2 , may influence the pharmacokinetics and lipid-lowering response to atorvastatin administration.

Association of genetic variations with pharmacokinetics and lipid-lowering response to atorvastatin in healthy Korean subjects

PubMed Central

Woo, Hye In; Kim, Suk Ran; Huh, Wooseong; Ko, Jae-Wook; Lee, Soo-Youn

2017-01-01

Background Statins are effective agents in the primary and secondary prevention of cardiovascular disease, but treatment response to statins varies among individuals. We analyzed multiple genetic polymorphisms and assessed pharmacokinetic and lipid-lowering responses after atorvastatin 80 mg treatment in healthy Korean individuals. Methods Atorvastatin 80 mg was given to 50 healthy Korean male volunteers. Blood samples were collected to measure plasma atorvastatin and lipid concentrations up to 48 hours after atorvastatin administration. Subjects were genotyped for 1,936 drug metabolism and transporter genetic polymorphisms using the Affymetrix DMET plus array. Results The pharmacokinetics and lipid-lowering effect of atorvastatin showed remarkable interindividual variation. Three polymorphisms in the SLCO1B1, SLCO1B3, and ABCC2 genes were associated with either the maximum concentration (Cmax) of atorvastatin or changes in total cholesterol or low-density lipoprotein cholesterol (LDL-C). Minor homozygotes (76.5 ng/mL) of SLCO1B1 c.-910G>A showed higher Cmax than heterozygotes (34.0 ng/mL) and major homozygotes (33.5 ng/mL, false discovery rate P=0.040). Cmax and the area under the plasma concentration curve from hour 0 to infinity (AUC∞) were higher in carriers of the SLCO1B1*17 haplotype that included c.-910G>A than in noncarriers (46.1 vs 32.8 ng/mL for Cmax; 221.5 vs 154.2 ng/mL for AUC∞). SLCO1B3 c.334G>T homozygotes (63.0 ng/mL) also showed higher Cmax than heterozygotes (34.7 ng/mL) and major homozygotes (31.4 ng/mL, FDR P=0.037). A nonsynonymous ABCC2 c.1249G>A was associated with small total cholesterol and LDL-C responses (0.23% and −0.70% for G/A vs −11.9% and −17.4% for G/G). The Cmax tended to increase according to the increase in the number of minor allele of SLCO1B1 c. −910G>A and SLCO1B3 c.334G>T. Conclusion Genetic polymorphisms in transporter genes, including SLCO1B1, SLCO1B3, and ABCC2, may influence the pharmacokinetics and lipid-lowering response to atorvastatin administration. PMID:28435225

Thermostable cross-protective subunit vaccine against Brucella species.

PubMed

Cherwonogrodzky, John W; Barabé, Nicole D; Grigat, Michelle L; Lee, William E; Poirier, Robert T; Jager, Scott J; Berger, Bradley J

2014-12-01

A subunit vaccine candidate was produced from Brucella suis 145 (biovar 4; expressing both the A antigen of Brucella abortus and the M antigen of Brucella melitensis). The preparation consisted mostly of polysaccharide (PS; >90% [wt/wt]; both cell-associated PS and exo-PS were combined) and a small amount of protein (1 to 3%) with no apparent nucleic acids. Vaccinated mice were protected (these had a statistically significant reduction in bacterial colonization compared to that of unvaccinated controls) when challenged with representative strains of three Brucella species most pathogenic for humans, i.e., B. abortus, B. melitensis, and B. suis. As little as 1 ng of the vaccine, without added adjuvant, protected mice against B. suis 145 infection (5 × 10(5) CFU), and a single injection of 1 μg of this subunit vaccine protected mice from B. suis 145 challenge for at least 14 months. A single immunization induced a serum IgG response to Brucella antigens that remained elevated for up to 9 weeks. The use of heat (i.e., boiling-water bath, autoclaving) in the vaccine preparation showed that it was thermostable. This method also ensured safety and security. The vaccine produced was immunogenic and highly protective against multiple strains of Brucella and represents a promising candidate for further evaluation. Copyright © 2014, American Society for Microbiology. All Rights Reserved.