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1

Characterization of the multicopper oxidase gene family in Anopheles gambiae  

PubMed Central

The multicopper oxidase (MCO) family of enzymes includes laccases, which oxidize a broad range of substrates including diphenols, and several oxidases with specific substrates such as iron, copper or ascorbic acid. We have identified five putative MCO genes in the genome of Anopheles gambiae and have cloned cDNAs encompassing the full coding region for each gene. MCO1 mRNA was detected in all developmental stages and in all of the larval and adult tissues tested. We observed an increase in MCO1 transcript abundance in the midguts and Malphighian tubules of adult females following a blood meal and in adult abdominal carcasses in response to an immune challenge. Two alternatively spliced isoforms of MCO2 mRNA were identified. The A isoform of MCO2 was previously detected in larval and pupal cuticle where it probably catalyzes sclerotization reactions (He et al., 2007). The B isoform was transcriptionally upregulated in ovaries in response to a blood meal. MCO3 mRNA was detected in the adult midgut, Malpighian tubules, and male reproductive tissues; like MCO1, it was upregulated in response to an immune challenge or a blood meal. MCO4 and MCO5 were observed primarily in eggs and in the abdominal carcass of larvae. A phylogenetic analysis of insect MCO genes identified putative orthologs of MCO1 and MCO2 in all of the insect genomes tested, whereas MCO3, MCO4 and MCO5 were found only in the two mosquito species analyzed. MCO2 orthologs have especially high sequence similarity, suggesting that they are under strong purifying selection; the A isoforms are more conserved than the B isoforms. The mosquito specific group shares a common ancestor with MCO2. This initial study of mosquito MCOs suggests that MCO2 may be required for egg development or eggshell tanning in addition to cuticle tanning, while MCO1 and MCO3 may be involved in metal metabolism or immunity.

Gorman, Maureen J.; Dittmer, Neal T.; Marshall, Jeremy L.; Kanost, Michael R.

2008-01-01

2

Multiple Multi-Copper Oxidase Gene Families in Basidiomycetes - What for?  

PubMed Central

Genome analyses revealed in various basidiomycetes the existence of multiple genes for blue multi-copper oxidases (MCOs). Whole genomes are now available from saprotrophs, white rot and brown rot species, plant and animal pathogens and ectomycorrhizal species. Total numbers (from 1 to 17) and types of mco genes differ between analyzed species with no easy to recognize connection of gene distribution to fungal life styles. Types of mco genes might be present in one and absent in another fungus. Distinct types of genes have been multiplied at speciation in different organisms. Phylogenetic analysis defined different subfamilies of laccases sensu stricto (specific to Agaricomycetes), classical Fe2+-oxidizing Fet3-like ferroxidases, potential ferroxidases/laccases exhibiting either one or both of these enzymatic functions, enzymes clustering with pigment MCOs and putative ascorbate oxidases. Biochemically best described are laccases sensu stricto due to their proposed roles in degradation of wood, straw and plant litter and due to the large interest in these enzymes in biotechnology. However, biological functions of laccases and other MCOs are generally little addressed. Functions in substrate degradation, symbiontic and pathogenic intercations, development, pigmentation and copper homeostasis have been put forward. Evidences for biological functions are in most instances rather circumstantial by correlations of expression. Multiple factors impede research on biological functions such as difficulties of defining suitable biological systems for molecular research, the broad and overlapping substrate spectrum multi-copper oxidases usually possess, the low existent knowledge on their natural substrates, difficulties imposed by low expression or expression of multiple enzymes, and difficulties in expressing enzymes heterologously.

Kues, Ursula; Ruhl, Martin

2011-01-01

3

SKS6 , a multicopper oxidase-like gene, participates in cotyledon vascular patterning during Arabidopsis thaliana development  

Microsoft Academic Search

SKU5-Similar 6 (SKS6) is a one of a large gene family of 19 members in Arabidopsis thaliana (L.) Heynh that encode multicopper oxidase-like proteins that are related to ferroxidases, ascorbate oxidases and laccases.\\u000a Only one member of the family has been previously studied; Skewed5 (SKU5) is involved in the control of root growth. The encoded SKS6 protein, like SKU5 appears

Jolanta Jacobs; Judith L. Roe

2005-01-01

4

Characterization of a multicopper oxidase gene cluster in Phanerochaete chrysosporium and evidence of altered splicing of the mco transcripts  

Microsoft Academic Search

A cluster of multicopper oxidase genes (mco1, mco2, mco3, mco4) from the lignin-degrading basidiomycete Phanerochaete chrysosporium is described. The four genes share the same transcriptional orientation within a 25 kb region. mco1, mco2 and mco3 are tightly grouped, with intergenic regions of 2?3 and 0?8 kb, respectively, whereas mco4 is located 11 kb upstream of mco1. All are transcriptionally active,

Luis F. Larrondo; Bernardo Gonzalez; Dan Cullen; Rafael Vicuna

2004-01-01

5

Multicopper oxidases and oxygenases  

Microsoft Academic Search

Copper is an essential trace element in living systems, present in the parts per million concentration range. It is a key cofactor in a diverse array of biological oxidation-reduction reactions. These involve either outer-sphere electron transfer, as in the blue copper proteins and the Cu{sub A} site of cytochrome oxidase and nitrous oxide redutase, or inner-sphere electron transfer in the

Edward I. Solomon; Uma M. Sundaram; Timothy E. Machonkin

1996-01-01

6

Multicopper oxidases and oxygenases  

SciTech Connect

Copper is an essential trace element in living systems, present in the parts per million concentration range. It is a key cofactor in a diverse array of biological oxidation-reduction reactions. These involve either outer-sphere electron transfer, as in the blue copper proteins and the Cu{sub A} site of cytochrome oxidase and nitrous oxide redutase, or inner-sphere electron transfer in the binding, activation, and reduction of dioxygen, superoxide, nitrite, and nitrous oxide. Copper sites have historically been divided into three classes based on their spectroscopic features, which reflect the geometric and electronic structure of the active site: type 1 (T1) or blue copper, type 2 (T2) or normal copper, and type 3 (T3) or coupled binuclear copper centers. 428 refs.

Solomon, E.I.; Sundaram, U.M.; Machonkin, T.E. [Stanford Univ., CA (United States). Dept. of Chemistry

1996-11-01

7

The Aspergillus niger multicopper oxidase family: analysis and overexpression of laccase-like encoding genes  

PubMed Central

Background Many filamentous fungal genomes contain complex groups of multicopper oxidase (MCO) coding genes that makes them a good source for new laccases with potential biotechnological interest. A bioinformatics analysis of the Aspergillus niger ATCC 1015 genome resulted in the identification of thirteen MCO genes. Ten of them were cloned and homologously overexpressed. Results A bioinformatic analysis of the A. niger ATCC 1015 genome revealed the presence of 13 MCO genes belonging to three different subfamilies on the basis of their phylogenetic relationships: ascomycete laccases, fungal pigment MCOs and fungal ferroxidases. According to in silico amino acid sequence analysis, the putative genes encoding for functional extracellular laccases (mcoA, mcoB, mcoC, mcoD, mcoE, mcoF, mcoG, mcoI, mcoJ and mcoM) were placed under the control of the glaA promoter and overexpressed in A. niger N593. Enzyme activity plate assays with several common laccase substrates showed that all genes are actually expressed and code for active MCOs. Interestingly, expressed enzymes show different substrate specificities. In addition, optimization of fungal pigment MCOs extracellular production was investigated. The performance of the widely used glucoamylase signal sequence (ssGlaA) in McoA secretion was studied. Results obtained suggest that ssGlaA do not yield higher levels of secreted McoA when compared to its native secretion signal. Also, McoB synthesis was investigated using different nitrogen sources in minimal medium liquid cultures. Higher yields of extracellular McoB were achieved with (NH4)2 tartrate. Conclusions Aspergillus niger is a good source of new laccases. The different substrate specificity observed in plate assays makes them interesting to be purified and biochemically compared. The homologous signal sequence of McoA has been shown to be a good choice for its extracellular overexpression. From the nitrogen sources tested (NH4)2 tartrate has been found to be the most appropriate for McoB production in A. niger.

2011-01-01

8

Characterization and mapping of a putative laccase-like multicopper oxidase gene in the barley (Hordeum vulgare L.).  

PubMed

Laccases constitute a multi-gene family of multi-copper glycoproteins. The barley laccase-like multicopper oxidase (LMCO) gene structure, the DNA sequence polymorphism and putative protein have not yet been described. As part of the study of LMCO in cereals, we have characterized the genomic structure of the putative LMCO gene HvLac1 from the barley variety 'Morex' and mapped HvLac1 on chromosome 4H. The genomic sequence of the HvLac1 gene is 2646 bp long and covers 100% of the coding region. It contains four exons and three introns. In this study, we have described the HvLac1 gene nucleotide polymorphisms (In/Del) in 134 barley varieties. Initial characterization of the barley and rice LMCO and the phylogeny analysis indicate that a monocot LMCO family is composed of five members. There are two high pI isoforms of putative HvLac1 protein derived from two in frame translation start codons with 602aa or 592aa residues. Isoforms differ in their predicted subcellular localization and both isoforms are characterized on C-terminus by the presence of the KDEL-like motif, which contributes to the accumulation of soluble proteins in the endoplasmic reticulum. Our results suggest that this unique feature of HvLac1 could be important for their role in physiological processes. PMID:22195580

Tomková, Lenka; Ku?era, Ladislav; Vaculová, Kate?ina; Milotová, Jarmila

2011-11-07

9

A cloned Bacillus halodurans multicopper oxidase exhibiting alkaline laccase activity  

Microsoft Academic Search

The gene product of open reading frame bh2082 from Bacillus halodurans C-125 was identified as a multicopper oxidase with potential laccase activity. A homologue of this gene, lbh1, was obtained from a B. halodurans isolate from our culture collection. The encoded gene product was expressed in Escherichia coli and showed laccase-like activity, oxidising 2,2?-azino-bis(3-ethylbenz-thiazoline-6-sulfonic acid), 2,6-dimethoxyphenol and syringaldazine (SGZ). The

H. J. Ruijssenaars; S. Hartmans

2004-01-01

10

Exploring laccase-like multicopper oxidase genes from the ascomycete Trichoderma reesei: a functional, phylogenetic and evolutionary study  

PubMed Central

Background The diversity and function of ligninolytic genes in soil-inhabiting ascomycetes has not yet been elucidated, despite their possible role in plant litter decay processes. Among ascomycetes, Trichoderma reesei is a model organism of cellulose and hemicellulose degradation, used for its unique secretion ability especially for cellulase production. T. reesei has only been reported as a cellulolytic and hemicellulolytic organism although genome annotation revealed 6 laccase-like multicopper oxidase (LMCO) genes. The purpose of this work was i) to validate the function of a candidate LMCO gene from T. reesei, and ii) to reconstruct LMCO phylogeny and perform evolutionary analysis testing for positive selection. Results After homologous overproduction of a candidate LMCO gene, extracellular laccase activity was detected when ABTS or SRG were used as substrates, and the recombinant protein was purified to homogeneity followed by biochemical characterization. The recombinant protein, called TrLAC1, has a molecular mass of 104 kDa. Optimal temperature and pH were respectively 40-45°C and 4, by using ABTS as substrate. TrLAC1 showed broad pH stability range of 3 to 7. Temperature stability revealed that TrLAC1 is not a thermostable enzyme, which was also confirmed by unfolding studies monitored by circular dichroism. Evolutionary studies were performed to shed light on the LMCO family, and the phylogenetic tree was reconstructed using maximum-likelihood method. LMCO and classical laccases were clearly divided into two distinct groups. Finally, Darwinian selection was tested, and the results showed that positive selection drove the evolution of sequences leading to well-known laccases involved in ligninolysis. Positively-selected sites were observed that could be used as targets for mutagenesis and functional studies between classical laccases and LMCO from T. reesei. Conclusions Homologous production and evolutionary studies of the first LMCO from the biomass-degrading fungus T. reesei gives new insights into the physicochemical parameters and biodiversity in this family.

2010-01-01

11

cumA, a gene encoding a multicopper oxidase, is involved in Mn{sup 2+} oxidation in Pseudomonas putida GB-1  

SciTech Connect

Pseudomonas putida GB-1-002 catalyzes the oxidation of Mn{sup 2+}. Nucleotide sequence analysis of the transposon insertion site of a nonoxidizing mutant revealed a gene (designated cumA) encoding a protein homologous to multicopper oxidases. Addition of Cu{sup 2+} increased the Mn{sup 2+}-oxidizing activity of the P. putida wild type by a factor of approximately 5. The growth rates of the wild type and the mutant were not affected by added Cu{sup 2+}. A second open reading frame (designated cumB) is located downstream from cumA. Both cumA and cumB probably are part of a single operon. The translation product of cumB was homologous to that of orf74 of Bradyrhizobium japonicum. A mutation in orf74 resulted in an extended lag phase and lower cell densities. Similar growth-related observations were made for the cumA mutant, suggesting that the cumA mutation may have a polar effect on cumB. This was confirmed by site-specific gene replacement in cumB. The cumB mutation did not affect the Mn{sup 2+}-oxidizing ability of the organism but resulted in decreased growth. In summary, the data indicate that the multicopper oxidase CumA is involved in the oxidation of Mn{sup 2+} and that CumB is required for optimal growth of P. putida GB-1-002.

Brouwers, G.J.; Vrind, J.P.M. de; Corstjens, P.L.A.M.; Vrind-de Jong, E.W. de [Leiden Univ. (Netherlands); Cornelis, P.; Baysse, C. [Vrije Univ. Brussel (Belgium). Dept. of Immunology, Paracytology and Ultrastructure

1999-04-01

12

Molecular cloning, chromosomal mapping, and sequence analysis of copper resistance genes from Xanthomonas campestris pv. juglandis: homology with small blue copper proteins and multicopper oxidase.  

PubMed Central

Copper-resistant strains of Xanthomonas campestris pv. juglandis occur in walnut orchards throughout northern California. The copper resistance genes from a copper-resistant strain C5 of X. campestris pv. juglandis were cloned and located on a 4.9-kb ClaI fragment, which hybridized only to DNA of copper-resistant strains of X. campestris pv. juglandis, and was part of an approximately 20-kb region which was conserved among such strains of X. campestris pv. juglandis. Hybridization analysis indicated that the copper resistance genes were located on the chromosome. Plasmids conferring copper resistance were not detected in copper-resistant strains, nor did mating with copper-sensitive strains result in copper-resistant transconjugants. Copper resistance genes from X. campestris pv. juglandis shared nucleotide sequence similarity with copper resistance genes from Pseudomonas syringae pv. tomato, P. syringae, and X. campestris pv. vesicatoria. DNA sequence analysis of the 4.9-kb fragment from strain C5 revealed that the sequence had an overall G+C content of 58.7%, and four open reading frames (ORF1 to ORF4), oriented in the same direction. All four ORFs were required for full expression of copper resistance, on the basis of Tn3-spice insertional inactivation and deletion analysis. The predicted amino acid sequences of ORF1 to ORF4 showed 65, 45, 47, and 40% identity with CopA, CopB, CopC, and CopD, respectively, from P. syringae pv. tomato. The most conserved regions are ORF1 and CopA and the C-terminal region (166 amino acids from the C terminus) of ORF2 and CopB. The hydrophobicity profiles of each pair of predicted polypeptides are similar except for the N terminus of ORF2 and CopB. Four histidine-rich polypeptide regions in ORF1 and CopA strongly resembled the copper-binding motifs of small blue copper proteins and multicopper oxidases, such as fungal laccases, plant ascorbate oxidase, and human ceruloplasmin. Putative copper ligands of the ORF1 polypeptide product are proposed, indicating that the polypeptide of ORF1 might bind four copper ions: one type 1, one type 2, and two type 3. Images

Lee, Y A; Hendson, M; Panopoulos, N J; Schroth, M N

1994-01-01

13

Exploring laccase-like multicopper oxidase genes from the ascomycete Trichoderma reesei: a functional, phylogenetic and evolutionary study  

Microsoft Academic Search

BACKGROUND: The diversity and function of ligninolytic genes in soil-inhabiting ascomycetes has not yet been elucidated, despite their possible role in plant litter decay processes. Among ascomycetes, Trichoderma reesei is a model organism of cellulose and hemicellulose degradation, used for its unique secretion ability especially for cellulase production. T. reesei has only been reported as a cellulolytic and hemicellulolytic organism

Anthony Levasseur; Markku Saloheimo; David Navarro; Martina Andberg; Pierre Pontarotti; Kristiina Kruus; Eric Record

2010-01-01

14

Multicopper oxidase-1 is a ferroxidase essential for iron homeostasis in Drosophila melanogaster  

PubMed Central

Multicopper ferroxidases catalyze the oxidation of ferrous iron to ferric iron. In yeast and algae, they participate in cellular uptake of iron; in mammals, they facilitate cellular efflux. The mechanisms of iron metabolism in insects are still poorly understood, and insect multicopper ferroxidases have not been identified. In this paper, we present evidence that Drosophila melanogaster multicopper oxidase-1 (MCO1) is a functional ferroxidase. We identified candidate iron-binding residues in the MCO1 sequence and found that purified recombinant MCO1 oxidizes ferrous iron. An association between MCO1 function and iron homeostasis was confirmed by two observations: RNAi-mediated knockdown of MCO1 resulted in decreased iron accumulation in midguts and whole insects, and weak knockdown increased the longevity of flies fed a toxic concentration of iron. Strong knockdown of MCO1 resulted in pupal lethality, indicating that MCO1 is an essential gene. Immunohistochemistry experiments demonstrated that MCO1 is located on the basal surfaces of the digestive system and Malpighian tubules. We propose that MCO1 oxidizes ferrous iron in the hemolymph and that the resulting ferric iron is bound by transferrin or melanotransferrin, leading to iron storage, iron withholding from pathogens, regulation of oxidative stress, and/or epithelial maturation. These proposed functions are distinct from those of other known ferroxidases. Given that MCO1 orthologues are present in all insect genomes analyzed to date, this discovery is an important step toward understanding iron metabolism in insects.

Lang, Minglin; Braun, Caroline L.; Kanost, Michael R.; Gorman, Maureen J.

2012-01-01

15

Molecular cloning and characterization of a novel metagenome-derived multicopper oxidase with alkaline laccase activity and highly soluble expression  

Microsoft Academic Search

Lac591, a gene encoding a novel multicopper oxidase with laccase activity, was identified through activity-based functional screening\\u000a of a metagenomic library from mangrove soil. Sequence analysis revealed that lac591 encodes a protein of 500 amino acids with a predicted molecular mass of 57.4 kDa. Lac591 was overexpressed heterologously\\u000a as soluble active enzyme in Escherichia coli and purified, giving rise to 380 mg

Mao Ye; Gang Li; Wei Qu Liang; Yu Huan Liu

2010-01-01

16

CotA, a Multicopper Oxidase from Bacillus pumilus WH4, Exhibits Manganese-Oxidase Activity  

PubMed Central

Multicopper oxidases (MCOs) are a family of enzymes that use copper ions as cofactors to oxidize various substrates. Previous research has demonstrated that several MCOs such as MnxG, MofA and MoxA can act as putative Mn(II) oxidases. Meanwhile, the endospore coat protein CotA from Bacillus species has been confirmed as a typical MCO. To study the relationship between CotA and the Mn(II) oxidation, the cotA gene from a highly active Mn(II)-oxidizing strain Bacillus pumilus WH4 was cloned and overexpressed in Escherichia coli strain M15. The purified CotA contained approximately four copper atoms per molecule and showed spectroscopic properties typical of blue copper oxidases. Importantly, apart from the laccase activities, the CotA also displayed substantial Mn(II)-oxidase activities both in liquid culture system and native polyacrylamide gel electrophoresis. The optimum Mn(II) oxidase activity was obtained at 53°C in HEPES buffer (pH 8.0) supplemented with 0.8 mM CuCl2. Besides, the addition of o-phenanthroline and EDTA both led to a complete suppression of Mn(II)-oxidizing activity. The specific activity of purified CotA towards Mn(II) was 0.27 U/mg. The Km, Vmax and kcat values towards Mn(II) were 14.85±1.17 mM, 3.01×10?6±0.21 M·min?1 and 0.32±0.02 s?1, respectively. Moreover, the Mn(II)-oxidizing activity of the recombinant E. coli strain M15-pQE-cotA was significantly increased when cultured both in Mn-containing K liquid medium and on agar plates. After 7-day liquid cultivation, M15-pQE-cotA resulted in 18.2% removal of Mn(II) from the medium. Furthermore, the biogenic Mn oxides were clearly observed on the cell surfaces of M15-pQE-cotA by scanning electron microscopy. To our knowledge, this is the first report that provides the direct observation of Mn(II) oxidation with the heterologously expressed protein CotA, Therefore, this novel finding not only establishes the foundation for in-depth study of Mn(II) oxidation mechanisms, but also offers a potential biocatalyst for Mn(II) removal.

Su, Jianmei; Bao, Peng; Bai, Tenglong; Deng, Lin; Wu, Hui; Liu, Fan; He, Jin

2013-01-01

17

CotA, a multicopper oxidase from Bacillus pumilus WH4, exhibits manganese-oxidase activity.  

PubMed

Multicopper oxidases (MCOs) are a family of enzymes that use copper ions as cofactors to oxidize various substrates. Previous research has demonstrated that several MCOs such as MnxG, MofA and MoxA can act as putative Mn(II) oxidases. Meanwhile, the endospore coat protein CotA from Bacillus species has been confirmed as a typical MCO. To study the relationship between CotA and the Mn(II) oxidation, the cotA gene from a highly active Mn(II)-oxidizing strain Bacillus pumilus WH4 was cloned and overexpressed in Escherichia coli strain M15. The purified CotA contained approximately four copper atoms per molecule and showed spectroscopic properties typical of blue copper oxidases. Importantly, apart from the laccase activities, the CotA also displayed substantial Mn(II)-oxidase activities both in liquid culture system and native polyacrylamide gel electrophoresis. The optimum Mn(II) oxidase activity was obtained at 53°C in HEPES buffer (pH 8.0) supplemented with 0.8 mM CuCl2. Besides, the addition of o-phenanthroline and EDTA both led to a complete suppression of Mn(II)-oxidizing activity. The specific activity of purified CotA towards Mn(II) was 0.27 U/mg. The Km, Vmax and kcat values towards Mn(II) were 14.85±1.17 mM, 3.01×10(-6)±0.21 M·min(-1) and 0.32±0.02 s(-1), respectively. Moreover, the Mn(II)-oxidizing activity of the recombinant E. coli strain M15-pQE-cotA was significantly increased when cultured both in Mn-containing K liquid medium and on agar plates. After 7-day liquid cultivation, M15-pQE-cotA resulted in 18.2% removal of Mn(II) from the medium. Furthermore, the biogenic Mn oxides were clearly observed on the cell surfaces of M15-pQE-cotA by scanning electron microscopy. To our knowledge, this is the first report that provides the direct observation of Mn(II) oxidation with the heterologously expressed protein CotA, Therefore, this novel finding not only establishes the foundation for in-depth study of Mn(II) oxidation mechanisms, but also offers a potential biocatalyst for Mn(II) removal. PMID:23577125

Su, Jianmei; Bao, Peng; Bai, Tenglong; Deng, Lin; Wu, Hui; Liu, Fan; He, Jin

2013-04-05

18

Crystal Structure of a Two-domain Multicopper Oxidase: Implications for the Evolution of Multicooper Blue Proteins  

SciTech Connect

The two-domain multicopper oxidases are proposed to be key intermediates in the evolution of three-domain multicopper oxidases. A number of two-domain multicopper oxidases have been identified from genome sequences and are classified as type A, type B, or type C on the basis of the predicted location of the type 1 copper center. The crystal structure of blue copper oxidase, a type C two-domain multicopper oxidase from Nitrosomonas europaea, has been determined to 1.9 A resolution. Blue copper oxidase is a trimer, of which each subunit comprises two cupredoxin domains. Each subunit houses a type 1 copper site in domain 1 and a type 2/type 3 trinuclear copper cluster at the subunit-subunit interface. The coordination geometry at the trinuclear copper site is consistent with reduction of the copper ions. Although the overall architecture of blue copper oxidase is similar to nitrite reductases, detailed structural alignments show that the fold and domain orientation more closely resemble the three-domain multicopper oxidases. These observations have important implications for the evolution of nitrite reductases and multicopper oxidases.

Lawton, Thomas J.; Sayavedra-Soto, Luis A.; Arp, Daniel J.; Rosenzweig, Amy C.; (Oregon State U.); (NWU)

2009-06-01

19

Multicopper oxidases: an innovative approach for oxygen management of aerobic organisms  

Microsoft Academic Search

Multicopper oxidases (MCOs), such as ascorbic acid oxidase and ceruloplasmin, are multidomain proteins capable of oxidizing\\u000a many structurally unrelated compounds reducing oxygen to water without ever generating reactive oxygen species. While MCOs\\u000a show great oxidative versatility, they can only transfer electrons to molecular oxygen, which is the obligate electron acceptor.\\u000a Therefore, MCOs could also be considered as “O2 consuming enzymes”,

Roberto ArrigoniOreste Arrigoni; Oreste Arrigoni

2010-01-01

20

Characterization of Laccase-like Multicopper Oxidases (LMCOs) in Arabidopsis thaliana  

SciTech Connect

Laccase-like multicopper oxidases (LMCOs) have repeatedly been associated with the process of lignification in plants, and previous work suggested that these enzymes might be acting as specific marker for highly localized, small-scale lignification events in tissues not typically thought of as lignified. However, plant LMCOs typically occur as members of gene families and different family members can display disparate enzyme activities and overlapping patterns of expression in bulk tissues. This study used reporter genes and knockout mutants to document the involvement of a specific Arabidopsis thaliana LMCO family member (At2g30210 ) in early root development, specifically with development of endodermal tissues. Expression of the gene product was found to be under the control of sucrose levels, but the gene also responded to fluctuations in salt concentrations. The expression patterns of this gene were consistent with its involvement in the formation of suberin in the Casparian strip of root endodermis. An additional LMCO (At5g58910) displayed a more generalized expression in the radicles emergent seedlings. Additional members of the Arabidopsis LMCO family (At2g29130, At5g01190, and At5g05390) were also investigated with reporter gene constructs and knockout mutants. Expression of these LMCOs was associated with lignifying xylem, and the genes had over-lapping expression. Single knockout mutants did not display obvious phenotypes, suggesting that the gene products might have degenerate functionality that could compensate for loss of a single LMCO function.

Jeffrey F.D. Dean

2008-06-09

21

A Novel Extracellular Multicopper Oxidase from Phanerochaete chrysosporium with Ferroxidase Activity  

PubMed Central

Lignin degradation by the white rot basidiomycete Phanerochaete chrysosporium involves various extracellular oxidative enzymes, including lignin peroxidase, manganese peroxidase, and a peroxide-generating enzyme, glyoxal oxidase. Recent studies have suggested that laccases also may be produced by this fungus, but these conclusions have been controversial. We identified four sequences related to laccases and ferroxidases (Fet3) in a search of the publicly available P. chrysosporium database. One gene, designated mco1, has a typical eukaryotic secretion signal and is transcribed in defined media and in colonized wood. Structural analysis and multiple alignments identified residues common to laccase and Fet3 sequences. A recombinant MCO1 (rMCO1) protein expressed in Aspergillus nidulans had a molecular mass of 78 kDa, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and the copper I-type center was confirmed by the UV-visible spectrum. rMCO1 oxidized various compounds, including 2,2?-azino(bis-3-ethylbenzthiazoline-6-sulfonate) (ABTS) and aromatic amines, although phenolic compounds were poor substrates. The best substrate was Fe2+, with a Km close to 2 ?M. Collectively, these results suggest that the P. chrysosporium genome does not encode a typical laccase but rather encodes a unique extracellular multicopper oxidase with strong ferroxidase activity.

Larrondo, Luis F.; Salas, Loreto; Melo, Francisco; Vicuna, Rafael; Cullen, Daniel

2003-01-01

22

Biocatalytic potential of laccase-like multicopper oxidases from Aspergillus niger  

PubMed Central

Background Laccase-like multicopper oxidases have been reported in several Aspergillus species but they remain uncharacterized. The biocatalytic potential of the Aspergillus niger fungal pigment multicopper oxidases McoA and McoB and ascomycete laccase McoG was investigated. Results The laccase-like multicopper oxidases McoA, McoB and McoG from the commonly used cell factory Aspergillus niger were homologously expressed, purified and analyzed for their biocatalytic potential. All three recombinant enzymes were monomers with apparent molecular masses ranging from 80 to 110 kDa. McoA and McoG resulted to be blue, whereas McoB was yellow. The newly obtained oxidases displayed strongly different activities towards aromatic compounds and synthetic dyes. McoB exhibited high catalytic efficiency with N,N-dimethyl-p-phenylenediamine (DMPPDA) and 2,2-azino-di(3-ethylbenzthiazoline) sulfonic acid (ABTS), and appeared to be a promising biocatalyst. Besides oxidizing a variety of phenolic compounds, McoB catalyzed successfully the decolorization and detoxification of the widely used textile dye malachite green. Conclusions The A. niger McoA, McoB, and McoG enzymes showed clearly different catalytic properties. Yellow McoB showed broad substrate specificity, catalyzing the oxidation of several phenolic compounds commonly present in different industrial effluents. It also harbored high decolorization and detoxification activity with the synthetic dye malachite green, showing to have an interesting potential as a new industrial biocatalyst.

2012-01-01

23

Iodide Oxidation by a Novel Multicopper Oxidase from the Alphaproteobacterium Strain Q-1  

PubMed Central

Alphaproteobacterium strain Q-1 is able to oxidize iodide (I?) to molecular iodine (I2) by an oxidase-like enzyme. One of the two isoforms of the iodide-oxidizing enzyme (IOE-II) produced by this strain was excised from a native polyacrylamide gel, eluted, and purified. IOE-II appeared as a single band (51 kDa) and showed significant in-gel iodide-oxidizing activity in sodium dodecyl sulfate-polyacrylamide gel electrophoresis without heat treatment. However, at least two bands with much higher molecular masses (150 and 230 kDa) were observed with heat treatment (95°C, 3 min). IOE-II was inhibited by NaN3, KCN, EDTA, and a copper chelator, o-phenanthroline. In addition to iodide, IOE-II showed significant activities toward phenolic compounds such as syringaldazine, 2,6-dimethoxy phenol, and p-phenylenediamine. IOE-II contained copper atoms as prosthetic groups and had UV/VIS absorption peaks at 320 and 590 nm. Comparison of several internal amino acid sequences obtained from trypsin-digested IOE-II with a draft genome sequence of strain Q-1 revealed that the products of two open reading frames (IoxA and IoxC), with predicted molecular masses of 62 and 71 kDa, are involved in iodide oxidation. Furthermore, subsequent tandem mass spectrometric analysis repeatedly detected peptides from IoxA and IoxC with high sequence coverage (32 to 40%). IoxA showed homology with the family of multicopper oxidases and included four copper-binding regions that are highly conserved among various multicopper oxidases. These results suggest that IOE-II is a multicopper oxidase and that it may occur as a multimeric complex in which at least two proteins (IoxA and IoxC) are associated.

Suzuki, Mio; Eda, Yoshifumi; Ohsawa, Shiaki; Kanesaki, Yu; Yoshikawa, Hirofumi; Tanaka, Kan; Muramatsu, Yasuyuki; Yoshikawa, Jun; Sato, Ikuo; Fujii, Takaaki

2012-01-01

24

The Laccase Engineering Database: a classification and analysis system for laccases and related multicopper oxidases  

PubMed Central

Laccases and their homologues form the protein superfamily of multicopper oxidases (MCO). They catalyze the oxidation of many, particularly phenolic substances, and, besides playing an important role in many cellular activities, are of interest in biotechnological applications. The Laccase Engineering Database (LccED, http://www.lcced.uni-stuttgart.de) was designed to serve as a tool for a systematic sequence-based classification and analysis of the diverse multicopper oxidase protein family. More than 2200 proteins were classified into 11 superfamilies and 56 homologous families. For each family, the LccED provides multiple sequence alignments, phylogenetic trees and family-specific HMM profiles. The integration of structures for 14 different proteins allows a comprehensive comparison of sequences and structures to derive biochemical properties. Among the families, the distribution of the proteins regarding different kingdoms was investigated. The database was applied to perform a comprehensive analysis by MCO- and laccase-specific patterns. The LccED combines information of sequences and structures of MCOs. It serves as a classification tool to assign new proteins to a homologous family and can be applied to investigate sequence–structure–function relationship and to guide protein engineering. Database URL: http://www.lcced.uni-stuttgart.de

Sirim, Demet; Wagner, Florian; Wang, Lei; Schmid, Rolf D; Pleiss, Jurgen

2011-01-01

25

Laccase versus laccase-like multi-copper oxidase: a comparative study of similar enzymes with diverse substrate spectra.  

PubMed

Laccases (EC 1.10.3.2) are multi-copper oxidases that catalyse the one-electron oxidation of a broad range of compounds including substituted phenols, arylamines and aromatic thiols to the corresponding radicals. Owing to their broad substrate range, copper-containing laccases are versatile biocatalysts, capable of oxidizing numerous natural and non-natural industry-relevant compounds, with water as the sole by-product. In the present study, 10 of the 11 multi-copper oxidases, hitherto considered to be laccases, from fungi, plant and bacterial origin were compared. A substrate screen of 91 natural and non-natural compounds was recorded and revealed a fairly broad but distinctive substrate spectrum amongst the enzymes. Even though the enzymes share conserved active site residues we found that the substrate ranges of the individual enzymes varied considerably. The EC classification is based on the type of chemical reaction performed and the actual name of the enzyme often refers to the physiological substrate. However, for the enzymes studied in this work such classification is not feasible, even more so as their prime substrates or natural functions are mainly unknown. The classification of multi-copper oxidases assigned as laccases remains a challenge. For the sake of simplicity we propose to introduce the term "laccase-like multi-copper oxidase" (LMCO) in addition to the term laccase that we use exclusively for the enzyme originally identified from the sap of the lacquer tree Rhus vernicifera. PMID:23755261

Reiss, Renate; Ihssen, Julian; Richter, Michael; Eichhorn, Eric; Schilling, Boris; Thöny-Meyer, Linda

2013-06-03

26

Impact of Copper Limitation on Expression and Function of Multicopper Oxidases (Ferroxidases)12  

PubMed Central

Copper is an essential trace element whose recommended intake is met by most North American diets. However, incidence of new cases of secondary copper deficiency is rising due to complications of gastric bypass surgery and high zinc exposure. Patients frequently are ataxic and anemic. Anemia of copper deficiency was first described in the 19th century, but the underlying biochemistry remains unknown. Approximately one dozen cuproenzymes have been characterized in mammals. Four of these are referred to as multicopper oxidases (MCO) due to their copper binding geometries. They have iron oxidase activity (ferroxidase). These include the hepatic secreted protein ceruloplasmin representing ?90% of plasma copper, a splice-variant of ceruloplasmin originally characterized in brain linked by glycosylphosphatidylinositol (GPI) to membranes, an intestinal enriched MCO named hephaestin, and newly described MCO in placenta called zyklopen. Limitation in available copper appears to limit function of the MCO group exhibited as impaired iron flux due to the copper requirement of MCO for their ferroxidase activity. Dietary copper deficiency is associated with lower levels of ceruloplasmin, GPI-ceruloplasmin, and hephaestin. Limitation of copper does not appear to limit synthesis of MCO but rather their stability and turnover. However, there appears to be a disconnect between limitation in MCO function and anemia, because humans and mice missing ceruloplasmin are not anemic despite hepatic iron overload and hypoferremia. Furthermore, anemic copper-deficient mammals are not improved by iron replacement. This suggests that the anemia of copper deficiency is not caused by iron limitation but rather impairment in iron utilization.

Prohaska, Joseph R.

2011-01-01

27

Multicopper oxidases: a workshop on copper coordination chemistry, electron transfer, and metallophysiology.  

PubMed

Multicopper oxidases (MCOs) are unique among copper proteins in that they contain at least one each of the three types of biologic copper sites, type 1, type 2, and the binuclear type 3. MCOs are descended from the family of small blue copper proteins (cupredoxins) that likely arose as a complement to the heme-iron-based cytochromes involved in electron transport; this event corresponded to the aerobiosis of the biosphere that resulted in the conversion of Fe(II) to Fe(III) as the predominant redox state of this essential metal and the solubilization of copper from Cu(2)S to Cu(H(2)O)( n ) (2+). MCOs are encoded in genomes in all three kingdoms and play essential roles in the physiology of essentially all aerobes. With four redox-active copper centers, MCOs share with terminal copper-heme oxidases the ability to catalyze the four-electron reduction of O(2) to two molecules of water. The electron transfers associated with this reaction are both outer and inner sphere in nature and their mechanisms have been fairly well established. A subset of MCO proteins exhibit specificity for Fe(2+), Cu(+), and/or Mn(2+) as reducing substrates and have been designated as metallooxidases. These enzymes, in particular the ferroxidases found in all fungi and metazoans, play critical roles in the metal metabolism of the expressing organism. PMID:19816718

Kosman, Daniel J

2009-10-09

28

A Multicopper Oxidase (Cj1516) and a CopA Homologue (Cj1161) Are Major Components of the Copper Homeostasis System of Campylobacter jejuni?  

PubMed Central

Metal ion homeostasis mechanisms in the food-borne human pathogen Campylobacter jejuni are poorly understood. The Cj1516 gene product is homologous to the multicopper oxidase CueO, which is known to contribute to copper tolerance in Escherichia coli. Here we show, by optical absorbance and electron paramagnetic resonance spectroscopy, that purified recombinant Cj1516 contains both T1 and trinuclear copper centers, which are characteristic of multicopper oxidases. Inductively coupled plasma mass spectrometry revealed that the protein contained approximately six copper atoms per polypeptide. The presence of an N-terminal “twin arginine” signal sequence suggested a periplasmic location for Cj1516, which was confirmed by the presence of p-phenylenediamine (p-PD) oxidase activity in periplasmic fractions of wild-type but not Cj1516 mutant cells. Kinetic studies showed that the pure protein exhibited p-PD, ferroxidase, and cuprous oxidase activities and was able to oxidize an analogue of the bacterial siderophore anthrachelin (3,4-dihydroxybenzoate), although no iron uptake impairment was observed in a Cj1516 mutant. However, this mutant was very sensitive to increased copper levels in minimal media, suggesting a role in copper tolerance. This was supported by increased expression of the Cj1516 gene in copper-rich media. A mutation in a second gene, the Cj1161c gene, encoding a putative CopA homologue, was also found to result in copper hypersensitivity, and a Cj1516 Cj1161c double mutant was found to be more copper sensitive than either single mutant. These observations and the apparent lack of alternative copper tolerance systems suggest that Cj1516 (CueO) and Cj1161 (CopA) are major proteins involved in copper homeostasis in C. jejuni.

Hall, Stephen J.; Hitchcock, Andrew; Butler, Clive S.; Kelly, David J.

2008-01-01

29

Mn(II,III) oxidation and MnO2 mineralization by an expressed bacterial multicopper oxidase.  

PubMed

Reactive Mn(IV) oxide minerals are ubiquitous in the environment and control the bioavailability and distribution of many toxic and essential elements and organic compounds. Their formation is thought to be dependent on microbial enzymes, because spontaneous Mn(II) to Mn(IV) oxidation is slow. Several species of marine Bacillus spores oxidize Mn(II) on their exosporium, the outermost layer of the spore, encrusting them with Mn(IV) oxides. Molecular studies have identified the mnx (Mn oxidation) genes, including mnxG, encoding a putative multicopper oxidase (MCO), as responsible for this two-electron oxidation, a surprising finding because MCOs only catalyze single-electron transfer reactions. Characterization of the enzymatic mechanism has been hindered by the lack of purified protein. By purifying active protein from the mnxDEFG expression construct, we found that the resulting enzyme is a blue (absorption maximum 590 nm) complex containing MnxE, MnxF, and MnxG proteins. Further, by analyzing the Mn(II)- and (III)-oxidizing activity in the presence of a Mn(III) chelator, pyrophosphate, we found that the complex facilitates both electron transfers from Mn(II) to Mn(III) and from Mn(III) to Mn(IV). X-ray absorption spectroscopy of the Mn mineral product confirmed its similarity to Mn(IV) oxides generated by whole spores. Our results demonstrate that Mn oxidation from soluble Mn(II) to Mn(IV) oxides is a two-step reaction catalyzed by an MCO-containing complex. With the purification of active Mn oxidase, we will be able to uncover its mechanism, broadening our understanding of Mn mineral formation and the bioinorganic capabilities of MCOs. PMID:23818588

Butterfield, Cristina N; Soldatova, Alexandra V; Lee, Sung-Woo; Spiro, Thomas G; Tebo, Bradley M

2013-07-01

30

Enhanced production of Aspergillus niger laccase-like multicopper oxidases through mRNA optimization of the glucoamylase expression system.  

PubMed

In filamentous fungi, most of the strategies used for the improvement of protein yields have been based on an increase in the transcript levels of a target gene. Strategies focusing at the translational level have been also described, but are far less explored. Here the 5' untranslated sequence of the glaA mRNA, a widely used expression system for the expression of recombinant proteins, was modified by the introduction of different nucleotide elements that have positive role in the translation process. Five Aspergillus niger laccase-like multicopper oxidases (MCOs) coding genes were fused to the native glaA 5'UTR and the three synthetic versions (sUTR1, sUTR2, and sUTR3) as well, and placed under the control of the glucoamylase gene promoter. Afterwards, a total of 20 fungal transformations were done using A. niger N593 as a recipient strain and 50 transformants per transformation were isolated and analyzed. The result of the incorporation of the synthetic 5'UTRs on the overall productivity of the transformants was assessed, on one hand by monitoring the laccase activity of all the isolated transformants, and on the other hand by quantifying and comparing the activity of those secreting the highest level of each MCO. For this purpose, a high-throughput method for the screening and selection of the best producers was developed. Once the best transformants producing the highest yield of McoA, McoB, McoC, McoD, and McoJ laccases were selected, their production level was quantified in supernatants of liquid cultures. The results obtained in this work indicate that modifications in the native glaA 5'UTR can lead to improvements in protein yields. PMID:22949265

Tamayo-Ramos, Juan Antonio; Barends, Sharief; de Lange, Dennis; de Jel, Annemarie; Verhaert, Raymond; de Graaff, Leo

2012-09-20

31

ATR-FTIR study of the protonation states of the Glu residue in the multicopper oxidases, CueO and bilirubin oxidase.  

PubMed

Redox-induced protonation state changes of the Glu residue in the multicopper oxidases, CueO and bilirubin oxidase (BO), were studied by attenuated total reflectance-Fourier transform infrared spectroscopy. By monitoring IR bands of the carboxylic acid C=O stretch in the wild-type and Glu-to-Gln mutant enzymes the Glu506 of CueO (Glu463 of BO) was found to be unprotonated in the oxidised and protonated in the reduced forms. The results provided direct evidence for proton uptake by the Glu, suggesting it plays a key role in the proton donation to the activated oxygen species in the catalytic cycle. PMID:20727354

Iwaki, Masayo; Kataoka, Kunishige; Kajino, Tsutomu; Sugiyama, Ryosuke; Morishita, Hirotoshi; Sakurai, Takeshi

2010-08-18

32

Characterization of cDNAs encoding putative laccase-like multicopper oxidases and developmental expression in the tobacco hornworm, Manduca sexta, and the malaria mosquito, Anopheles gambiae  

Microsoft Academic Search

Laccase (EC 1.10.3.2) is an enzyme with p-diphenol oxidase activity that is a member of a group of proteins collectively known as multicopper, or blue copper, oxidases. Laccase is hypothesized to play an important role in insect cuticle sclerotization by oxidizing catechols in the cuticle to their corresponding quinones, which then catalyze protein cross-linking reactions. To facilitate studies of the

Neal T. Dittmer; Richard J. Suderman; Haobo Jiang; Yu-Cheng Zhu; Maureen J. Gorman; Karl J. Kramer; Michael R. Kanost

2004-01-01

33

Characterization of endogenous and recombinant forms of laccase-2, a multicopper oxidase from the tobacco hornworm, Manduca sexta  

PubMed Central

Laccases belong to the group of multicopper oxidases that exhibit wide substrate specificity for polyphenols and aromatic amines. They are found in plants, fungi, bacteria, and insects. In insects the only known role for laccase is in cuticle sclerotization. However, extracting laccase from the insect’s cuticle requires proteolysis, resulting in an enzyme that is missing its amino-terminus. To circumvent this problem, we expressed and purified full-length and amino-terminally truncated recombinant forms of laccase-2 from the tobacco hornworm, Manduca sexta. We also purified the endogenous enzyme from the pharate pupal cuticle and used peptide mass fingerprinting analysis to confirm that it is laccase-2. All three enzymes had pH optima between 5 and 5.5 when using N-acetyldopamine (NADA) or N-?-alanyldopamine (NBAD) as substrates. The laccases exhibited typical Michaelis-Menten kinetics when NADA was used as a substrate, with Km values of 0.46 mM, 0.43 mM, and 0.63 mM, respectively, for the full-length recombinant, truncated recombinant, and cuticular laccases; the apparent kcat values were 100 min?1, 80 min?1, and 290 min?1. The similarity in activity of the two recombinant laccases suggests that laccase-2 is expressed in an active form rather than as a zymogen, as had been previously proposed. This conclusion is consistent with the detection of activity in untanned pupal wing cuticle using the laccase substrate 2,2?-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). Immunoblot analysis of proteins extracted from both tanned and untanned cuticle detected only a single protein of 84 kDa, consistent with the full-length enzyme. With NBAD as substrate, the full-length recombinant and cuticular laccases showed kinetics indicative of substrate inhibition, with Km values of 1.9 mM and 0.47 mM, respectively, and apparent kcat values of 200 min?1 and 180 min?1. These results enhance our understanding of cuticle sclerotization, and may aid in the design of insecticides targeting insect laccases.

Dittmer, Neal T.; Gorman, Maureen J.; Kanost, Michael R.

2009-01-01

34

Characterization of endogenous and recombinant forms of laccase-2, a multicopper oxidase from the tobacco hornworm, Manduca sexta.  

PubMed

Laccases belong to the group of multicopper oxidases that exhibit wide substrate specificity for polyphenols and aromatic amines. They are found in plants, fungi, bacteria, and insects. In insects the only known role for laccase is in cuticle sclerotization. However, extracting laccase from the insect's cuticle requires proteolysis, resulting in an enzyme that is missing its amino-terminus. To circumvent this problem, we expressed and purified full-length and amino-terminally truncated recombinant forms of laccase-2 from the tobacco hornworm, Manduca sexta. We also purified the endogenous enzyme from the pharate pupal cuticle and used peptide mass fingerprinting analysis to confirm that it is laccase-2. All three enzymes had pH optima between 5 and 5.5 when using N-acetyldopamine (NADA) or N-beta-alanyldopamine-alanyldopamine (NBAD) as substrates. The laccases exhibited typical Michaelis-Menten kinetics when NADA was used as a substrate, with K(m) values of 0.46 mM, 0.43 mM, and 0.63 mM, respectively, for the full-length recombinant, truncated recombinant, and cuticular laccases; the apparent k(cat) values were 100 min(-1), 80 min(-1), and 290 min(-1). The similarity in activity of the two recombinant laccases suggests that laccase-2 is expressed in an active form rather than as a zymogen, as had been previously proposed. This conclusion is consistent with the detection of activity in untanned pupal wing cuticle using the laccase substrate 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). Immunoblot analysis of proteins extracted from both tanned and untanned cuticle detected only a single protein of 84 kDa, consistent with the full-length enzyme. With NBAD as substrate, the full-length recombinant and cuticular laccases showed kinetics indicative of substrate inhibition, with K(m) values of 1.9 mM and 0.47 mM, respectively, and apparent k(cat) values of 200 min(-1) and 180 min(-1). These results enhance our understanding of cuticle sclerotization, and may aid in the design of insecticides targeting insect laccases. PMID:19576986

Dittmer, Neal T; Gorman, Maureen J; Kanost, Michael R

2009-07-02

35

Molecular dynamics of a thermostable multicopper oxidase from Thermus thermophilus HB27: structural differences between the apo and holo forms.  

PubMed

Molecular dynamic (MD) simulations have been performed on Tth-MCO, a hyperthermophilic multicopper oxidase from thermus thermophilus HB27, in the apo as well as the holo form, with the aim of exploring the structural dynamic properties common to the two conformational states. According to structural comparison between this enzyme and other MCOs, the substrate in process to electron transfer in an outer-sphere event seems to transiently occupy a shallow and overall hydrophobic cavity near the Cu type 1 (T1Cu). The linker connecting the ?-strands 21 and 24 of the second domain (loop (?21-?24)(D2)) has the same conformation in both states, forming a flexible lid at the entrance of the electron-transfer cavity. Loop (?21-?24)(D2) has been tentatively assigned a role occluding the access to the electron-transfer site. The dynamic of the loop (?21-?24)(D2) has been investigated by MD simulation, and results show that the structures of both species have the same secondary and tertiary structure during almost all the MD simulations. In the simulation, loop (?21-?24)(D2) of the holo form undergoes a higher mobility than in the apo form. In fact, loop (?21-?24)(D2) of the holo form experiences a conformational change which enables exposure to the electron-transfer site (open conformation), while in the apo form the opposite effect takes place (closed conformation). To confirm the hypothesis that the open conformation might facilitate the transient electron-donor molecule occupation of the site, the simulation was extended another 40 ns with the electron-donor molecule docked into the protein cavity. Upon electron-donor molecule stabilization, loops near the cavity reduce their mobility. These findings show that coordination between the copper and the protein might play an important role in the general mobility of the enzyme, and that the open conformation seems to be required for the electron transfer process to T1Cu. PMID:22808237

Bello, Martiniano; Valderrama, Brenda; Serrano-Posada, Hugo; Rudiño-Piñera, Enrique

2012-07-10

36

Crystal structure of a blue laccase from Lentinus tigrinus: evidences for intermediates in the molecular oxygen reductive splitting by multicopper oxidases  

PubMed Central

Background Laccases belong to multicopper oxidases, a widespread class of enzymes implicated in many oxidative functions in pathogenesis, immunogenesis and morphogenesis of organisms and in the metabolic turnover of complex organic substances. They catalyze the coupling between the four one-electron oxidations of a broad range of substrates with the four-electron reduction of dioxygen to water. These catalytic processes are made possible by the contemporaneous presence of at least four copper ion sites, classified according to their spectroscopic properties: one type 1 (T1) site where the electrons from the reducing substrates are accepted, one type 2 (T2), and a coupled binuclear type 3 pair (T3) which are assembled in a T2/T3 trinuclear cluster where the electrons are transferred to perform the O2 reduction to H2O. Results The structure of a laccase from the white-rot fungus Lentinus (Panus) tigrinus, a glycoenzyme involved in lignin biodegradation, was solved at 1.5 Å. It reveals a asymmetric unit containing two laccase molecules (A and B). The progressive reduction of the copper ions centers obtained by the long-term exposure of the crystals to the high-intensity X-ray synchrotron beam radiation under aerobic conditions and high pH allowed us to detect two sequential intermediates in the molecular oxygen reduction pathway: the "peroxide" and the "native" intermediates, previously hypothesized through spectroscopic, kinetic and molecular mechanics studies. Specifically the electron-density maps revealed the presence of an end-on bridging, ?-?1:?1 peroxide ion between the two T3 coppers in molecule B, result of a two-electrons reduction, whereas in molecule A an oxo ion bridging the three coppers of the T2/T3 cluster (?3-oxo bridge) together with an hydroxide ion externally bridging the two T3 copper ions, products of the four-electrons reduction of molecular oxygen, were best modelled. Conclusion This is the first structure of a multicopper oxidase which allowed the detection of two intermediates in the molecular oxygen reduction and splitting. The observed features allow to positively substantiate an accurate mechanism of dioxygen reduction catalyzed by multicopper oxidases providing general insights into the reductive cleavage of the O-O bonds, a leading problem in many areas of biology.

Ferraroni, Marta; Myasoedova, Nina M; Schmatchenko, Vadim; Leontievsky, Alexey A; Golovleva, Ludmila A; Scozzafava, Andrea; Briganti, Fabrizio

2007-01-01

37

Melon ascorbate oxidase: cloning of a multigene family, induction during fruit development and repression by wounding  

Microsoft Academic Search

A small family of at least four genes encoding melon ascorbate oxidase (AO) has been identified and three members of it have been cloned. Preliminary DNA sequence determination suggested that melon AO genes code for enzymes homologous to ascorbate oxidases from other plants and similar to other multicopper oxidases. We describe detailed molecular studies addressing melon AO expression during organ

George Diallinas; Irene Pateraki; Maite Sanmartin; Angela Scossa; Eugenia Stilianou; Nickolas J. Panopoulos; Angelos K. Kanellis

1997-01-01

38

Structural changes caused by radiation-induced reduction and radiolysis: the effect of X-ray absorbed dose in a fungal multicopper oxidase  

PubMed Central

X-ray radiation induces two main effects at metal centres contained in protein crystals: radiation-induced reduction and radiolysis and a resulting decrease in metal occupancy. In blue multicopper oxidases (BMCOs), the geometry of the active centres and the metal-to-ligand distances change depending on the oxidation states of the Cu atoms, suggesting that these alterations are catalytically relevant to the binding, activation and reduction of O2. In this work, the X-ray-determined three-dimensional structure of laccase from the basidiomycete Coriolopsis gallica (Cg L), a high catalytic potential BMCO, is described. By combining spectroscopic techniques (UV–Vis, EPR and XAS) and X-ray crystallography, structural changes at and around the active copper centres were related to pH and absorbed X-­ray dose (energy deposited per unit mass). Depletion of two of the four active Cu atoms as well as low occupancies of the remaining Cu atoms, together with different conformations of the metal centres, were observed at both acidic pH and high absorbed dose, correlating with more reduced states of the active coppers. These observations provide additional evidence to support the role of flexibility of copper sites during O2 reduction. This study supports previous observations indicating that interpretations regarding redox state and metal coordination need to take radiation effects explicitly into account.

De la Mora, Eugenio; Lovett, Janet E.; Blanford, Christopher F.; Garman, Elspeth F.; Valderrama, Brenda; Rudino-Pinera, Enrique

2012-01-01

39

Thermostable multicopper oxidase from Thermus thermophilus HB27: crystallization and preliminary X-ray diffraction analysis of apo and holo forms.  

PubMed

A thermostable multicopper oxidase from Thermus thermophilus HB27 (Tth-MCO) was successfully crystallized using the sitting-drop and hanging-drop vapour-diffusion methods. Crystallization conditions and preliminary X-ray diffraction data to 1.5 Å resolution obtained using synchrotron radiation at 100 K are reported. The crystals belonged to space group C222(1), with unit-cell parameters a = 93.6, b = 110.3, c = 96.3 Å. A monomer in the asymmetric unit yielded a Matthews coefficient (V(M)) of 2.60 Å(3) Da(-1) and a solvent content of 53%. An inactive enzyme form, apo-Tth-MCO, was also crystallized and diffraction data were collected to 1.7 Å resolution. In addition, a second inactive form of the enzyme, Hg-Tth-MCO, was obtained by soaking apo-Tth-MCO crystals with mercury(II) chloride and data were collected to a resolution of 1.7 Å. PMID:22139175

Serrano-Posada, Hugo; Valderrama, Brenda; Stojanoff, Vivian; Rudiño-Piñera, Enrique

2011-11-26

40

Structural changes caused by radiation-induced reduction and radiolysis: the effect of X-ray absorbed dose in a fungal multicopper oxidase.  

PubMed

X-ray radiation induces two main effects at metal centres contained in protein crystals: radiation-induced reduction and radiolysis and a resulting decrease in metal occupancy. In blue multicopper oxidases (BMCOs), the geometry of the active centres and the metal-to-ligand distances change depending on the oxidation states of the Cu atoms, suggesting that these alterations are catalytically relevant to the binding, activation and reduction of O(2). In this work, the X-ray-determined three-dimensional structure of laccase from the basidiomycete Coriolopsis gallica (Cg L), a high catalytic potential BMCO, is described. By combining spectroscopic techniques (UV-Vis, EPR and XAS) and X-ray crystallography, structural changes at and around the active copper centres were related to pH and absorbed X-ray dose (energy deposited per unit mass). Depletion of two of the four active Cu atoms as well as low occupancies of the remaining Cu atoms, together with different conformations of the metal centres, were observed at both acidic pH and high absorbed dose, correlating with more reduced states of the active coppers. These observations provide additional evidence to support the role of flexibility of copper sites during O(2) reduction. This study supports previous observations indicating that interpretations regarding redox state and metal coordination need to take radiation effects explicitly into account. PMID:22525754

De la Mora, Eugenio; Lovett, Janet E; Blanford, Christopher F; Garman, Elspeth F; Valderrama, Brenda; Rudino-Pinera, Enrique

2012-04-17

41

Crystal Structures of Multicopper Oxidase CueO Bound to Copper(I) and Silver(I): Functional Role of a Methonine-Rich Sequence  

SciTech Connect

The multicopper oxidase CueO oxidizes toxic Cu(I) and is required for copper homeostasis in Escherichia coli. Like many proteins involved in copper homeostasis, CueO has a methionine-rich segment that is thought to be critical for copper handling. How such segments function is poorly understood. Here, we report the crystal structure of CueO at 1.1 {angstrom} with the 45-residue methionine-rich segment fully resolved, revealing an N-terminal helical segment with methionine residues juxtaposed for Cu(I) ligation and a C-terminal highly mobile segment rich in methionine and histidine residues. We also report structures of CueO with a C500S mutation, which leads to loss of the T1 copper, and CueO with six methionines changed to serine. Soaking C500S CueO crystals with Cu(I), or wild-type CueO crystals with Ag(I), leads to occupancy of three sites, the previously identified substrate-binding site and two new sites along the methionine-rich helix, involving methionines 358, 362, 368, and 376. Mutation of these residues leads to a {approx}4-fold reduction in kcat for Cu(I) oxidation. Ag(I), which often appears with copper in nature, strongly inhibits CueO oxidase activities in vitro and compromises copper tolerance in vivo, particularly in the absence of the complementary copper efflux cus system. Together, these studies demonstrate a role for the methionine-rich insert of CueO in the binding and oxidation of Cu(I) and highlight the interplay among cue and cus systems in copper and silver homeostasis.

Singh, Satish K.; Roberts, Sue A.; McDevitt, Sylvia F.; Weichsel, Andrzej; Wildner, Guenter F.; Grass, Gregor B.; Rensing, Christopher; Montfort, William R. (Skidmore); (Bundeswehr); (Ariz)

2011-10-24

42

The Two Oxidized Forms of the Trinuclear Cu Cluster in the Multicopper Oxidases And Mechanism for the Decay of the Native Intermediate  

SciTech Connect

Multicopper oxidases (MCOs) catalyze the 4e{sup -} reduction of O2 to H2O. The reaction of the fully reduced enzyme with O2 generates the native intermediate (NI), which undergoes a slow decay to the resting enzyme in the absence of substrate. NI is a fully oxidized form, but its spectral features are very different from those of the resting form (also fully oxidized), because the type 2 and the coupled-binuclear type 3 Cu centers in the O2-reducing trinuclear Cu cluster site are isolated in the resting enzyme, whereas these are all bridged by a {mu}3-oxo ligand in NI. Notably, the one azide-bound NI (NI{sub Az}) exhibits spectral features very similar to those of NI, in which the {mu}3-oxo ligand in NI has been replaced by a {mu}3-bridged azide. Comparison of the spectral features of NI and NIAz, combined with density functional theory (DFT) calculations, allows refinement of the NI structure. The decay of NI to the resting enzyme proceeds via successive proton-assisted steps, whereas the rate-limiting step involves structural rearrangement of the {mu}3-oxo-bridge from inside to outside the cluster. This phenomenon is consistent with the slow rate of NI decay that uncouples the resting enzyme from the catalytic cycle, leaving NI as the catalytically relevant fully oxidized form of the MCO active site. The all-bridged structure of NI would facilitate electron transfer to all three Cu centers of the trinuclear cluster for rapid proton-coupled reduction of NI to the fully reduced form for catalytic turnover.

Yoon, J.; Liboiron, B.D.; Sarangi, R.; Hodgson, K.O.; Hedman, B.; Solomona, E.I.; /Stanford U., Chem. Dept. /SLAC, SSRL

2007-10-10

43

The two oxidized forms of the trinuclear Cu cluster in the multicopper oxidases and mechanism for the decay of the native intermediate  

PubMed Central

Multicopper oxidases (MCOs) catalyze the 4e? reduction of O2 to H2O. The reaction of the fully reduced enzyme with O2 generates the native intermediate (NI), which undergoes a slow decay to the resting enzyme in the absence of substrate. NI is a fully oxidized form, but its spectral features are very different from those of the resting form (also fully oxidized), because the type 2 and the coupled-binuclear type 3 Cu centers in the O2-reducing trinuclear Cu cluster site are isolated in the resting enzyme, whereas these are all bridged by a ?3-oxo ligand in NI. Notably, the one azide-bound NI (NIAz) exhibits spectral features very similar to those of NI, in which the ?3-oxo ligand in NI has been replaced by a ?3-bridged azide. Comparison of the spectral features of NI and NIAz, combined with density functional theory (DFT) calculations, allows refinement of the NI structure. The decay of NI to the resting enzyme proceeds via successive proton-assisted steps, whereas the rate-limiting step involves structural rearrangement of the ?3-oxo-bridge from inside to outside the cluster. This phenomenon is consistent with the slow rate of NI decay that uncouples the resting enzyme from the catalytic cycle, leaving NI as the catalytically relevant fully oxidized form of the MCO active site. The all-bridged structure of NI would facilitate electron transfer to all three Cu centers of the trinuclear cluster for rapid proton-coupled reduction of NI to the fully reduced form for catalytic turnover.

Yoon, Jungjoo; Liboiron, Barry D.; Sarangi, Ritimukta; Hodgson, Keith O.; Hedman, Britt; Solomon, Edward I.

2007-01-01

44

Systematic Perturbation of the Trinuclear Copper Cluster in the Multicopper Oxidases: The Role of Active Site Asymmetry in its Reduction of O2 to H2O  

PubMed Central

The multicopper oxidase Fet3p catalyzes the four-electron reduction of dioxygen to water, coupled to the one-electron oxidation of four equivalents of substrate. To carry out this process the enzyme utilizes four Cu atoms: a type 1, a type 2, and a coupled binuclear, type 3 site. Substrates are oxidized at the T1 Cu, which rapidly transfers electrons, 13 Å away, to a trinuclear copper cluster composed of the T2 and T3 sites where dioxygen is reduced to water in two sequential 2e? steps. This study focuses on two variants of Fet3p, H126Q and H483Q, that perturb the two T3 Cu's, T3? and T3?, respectively. The variants have been isolated in both holo and type 1 depleted (T1D) forms, T1DT3?Q and T1DT3?Q, and their trinuclear copper clusters have been characterized in their oxidized and reduced states. While the variants are only mildly perturbed relative to T1D in the resting oxidized state, in contrast to T1D they are both found to have lost a ligand in their reduced states. Importantly, T1DT3?Q reacts with O2 but T1DT3?Q does not. Thus loss of a ligand at T3?, but not at T3?, turns off O2 reactivity, indicating that T3? and T2 are required for the 2e? reduction of O2 to form the peroxide intermediate (PI), whereas T3? remains reduced. This is supported by the spectroscopic features of PI in T1DT3?Q, which are identical to T1D PI. This selective redox activity of one edge of the trinuclear cluster demonstrates its asymmetry in O2 reactivity. The structural origin of this asymmetry between the T3? and T3? is discussed as is its contribution to reactivity.

Augustine, Anthony J.; Kjaergaard, Christian; Qayyum, Munzarin; Ziegler, Lynn; Kosman, Daniel J.; Hodgson, Keith O.; Hedman, Britt; Solomon, Edward I.

2010-01-01

45

[Oxidase gene from sweetpotato].  

PubMed

Polyphenol oxidase is the enzyme responsible for enzymatic browning in sweetpotato that decreases the commercial value of sweetpotato products. Here we reported the cloning and characterization of a new cDNA encoding PPO from sweetpotato, designated as IbPPO (GeneBank accession number: AY822711). The full-length cDNA of IbPPO is 1984 bp with a 1767 bp open reading frame (ORF) encoding a 588 amino acid polypeptide with calculated molecular weight of 65.7 kDa and theoretical pI of 6.28. The coding sequence of IbPPO was also directly amplified from the genomic DNA of sweetpotato that demonstrated that IbPPO was an intron-free gene. The computational comparative analysis revealed that IbPPO showed homology to other PPOs of plant origin and contained a 50 amino acid plastidial transit peptides at its N-terminal and the two conserved CuA and CuB copper-binding motifs in the catalytic region of IbPPO. A highly conserved serine-rich motif was firstly found in the transit peptides of plant PPO enzymes. Then the homology-based structural modeling of IbPPO showed that IbPPO had the typical structure of PPO: the catalytic copper center was accommodated in a central four-helix bundle located in a hydrophobic pocket close to the surface. Finally, the results of the semi-quantitative RT-PCR analysis of IbPPO in different tissues demonstrated that IbPPO could express in all the organs of sweetpotato including: mature leaves, young leaves, the stems of mature leaves (petioles), the storage roots and the veins but at different levels. The highest-level expression of IbPPO was found in veins, followed by storage roots, young leaves and mature leaves; and the lowest-level expression of IbPPO was found in petioles. The present researches will facilitate the development of anti-brown sweetpotato by genetic engineering. PMID:17209428

Liao, Zhihua; Chen, Rong; Chen, Min; Yang, Yijian; Fu, Yufan; Zhang, Qitang; Lan, Xiaozhong

46

Four-electron Reduction of Dioxygen by a Multicopper Oxidase, CueO, and Roles of Asp112 and Glu506 Located Adjacent to the Trinuclear Copper Center*S?  

PubMed Central

The mechanism of the four-electron reduction of dioxygen by a multicopper oxidase, CueO, was studied based on reactions of single and double mutants with Cys500, a type I copper ligand, and the noncoordinating Asp112 and Glu506, which form hydrogen bonds with the trinuclear copper center directly and indirectly via a water molecule. The reaction of C500S containing a vacant type I copper center produced intermediate I in an EPR-silent peroxide-bound form. The formation of intermediate I from C500S/D112N was restricted due to a reduction in the affinity of the trinuclear copper center for dioxygen. The state of intermediate I was realized to be the resting form of C500S/E506Q and C500S of the truncated mutant ??5–7CueO, in which the 50 amino acids covering the substrate-binding site were removed. Reactions of the recombinant CueO and E506Q afforded intermediate II, a fully oxidized form different from the resting one, with a very broad EPR signal, g < 2, detectable only at cryogenic temperatures and unsaturated with high power microwaves. The lifetime of intermediate II was prolonged by the mutation at Glu506 involved in the donation of protons. The structure of intermediates I and II and the mechanism of the four-electron reduction of dioxygen driven by Asp112 and Glu506 are discussed.

Kataoka, Kunishige; Sugiyama, Ryosuke; Hirota, Shun; Inoue, Megumi; Urata, Kanae; Minagawa, Yoichi; Seo, Daisuke; Sakurai, Takeshi

2009-01-01

47

Molecular cloning and functional characterization of a unique multipotent polyphenol oxidase from Marinomonas mediterranea  

Microsoft Academic Search

Marinomonas mediterranea is a recently isolated melanogenic marine bacterium containing laccase and tyrosinase activities. These activities are due to the expression of two polyphenol oxidases (PPOs), a blue multicopper laccase and an SDS-activated tyrosinase. The gene encoding the first one, herein denominated M. mediterranea PpoA, has been isolated by transposon mutagenesis, cloned and expressed in Escherichia coli. Its predicted amino

Antonio Sanchez-Amat; Patricia Lucas-El??o; Eva Fernández; Jose Carlos Garc??a-Borrón; Francisco Solano

2001-01-01

48

The mammalian aldehyde oxidase gene family  

PubMed Central

Aldehyde oxidases (EC 1.2.3.1) are a small group of structurally conserved cytosolic proteins represented in both the animal and plant kingdoms. In vertebrates, aldehyde oxidases constitute the small sub-family of molybdo-flavoenzymes, along with the evolutionarily and structurally related protein, xanthine oxidoreductase. These enzymes require a molybdo-pterin cofactor (molybdenum cofactor, MoCo) and flavin adenine dinucleotide for their catalytic activity. Aldehyde oxidases have broad substrate specificity and catalyse the hydroxylation of N-heterocycles and the oxidation of aldehydes to the corresponding acid. In humans, a single aldehyde oxidase gene (AOX1) and two pseudogenes clustering on a short stretch of chromosome 2q are known. In other mammals, a variable number of structurally conserved aldehyde oxidase genes has been described. Four genes (Aox1, Aox3, Aox4 and Aox3l1), coding for an equivalent number of catalytically active enzymes, are present in the mouse and rat genomes. Although human AOX1 and its homologous proteins are best known as drug metabolising enzymes, the physiological substrate(s) and function(s) are as yet unknown. The present paper provides an update of the available information on the evolutionary history, tissue- and cell-specific distribution and function of mammalian aldehyde oxidases.

2009-01-01

49

Spectroscopic Studies of Perturbed T1 Cu Sites in the Multicopper Oxidases Saccharomyces Cerevisiae Fet3p And Rhus Vernicifera Laccase: Allosteric Coupling Between the T1 And Trinuclear Cu Sites  

SciTech Connect

The multicopper oxidases catalyze the 4e{sup -} reduction of O{sub 2} to H{sub 2}O coupled to the 1e{sup -} oxidation of 4 equiv of substrate. This activity requires four Cu atoms, including T1, T2, and coupled binuclear T3 sites. The T2 and T3 sites form a trinuclear cluster (TNC) where O{sub 2} is reduced. The T1 is coupled to the TNC through a T1-Cys-His-T3 electron transfer (ET) pathway. In this study the two T3 Cu coordinating His residues which lie in this pathway in Fet3 have been mutated, H483Q, H483C, H485Q, and H485C, to study how perturbation at the TNC impacts the T1 Cu site. Spectroscopic methods, in particular resonance Raman (rR), show that the change from His to Gln to Cys increases the covalency of the T1 Cu?S Cys bond and decreases its redox potential. This study of T1?TNC interactions is then extended to Rhus vernicifera laccase where a number of well-defined species including the catalytically relevant native intermediate (NI) can be trapped for spectroscopic study. The T1 Cu?S covalency and potential do not change in these species relative to resting oxidized enzyme, but interestingly the differences in the structure of the TNC in these species do lead to changes in the T1 Cu rR spectrum. This helps to confirm that vibrations in the cysteine side chain of the T1 Cu site and the protein backbone couple to the Cu?S vibration. These changes in the side chain and backbone provide a possible mechanism for regulating intramolecular T1 to TNC ET in NI and partially reduced enzyme forms for efficient turnover.

Augustine, A.J.; Kragh, M.E.; Sarangi, R.; Fujii, S.; Liboiron, B.D.; Stoj, C.S.; Kosman, D.J.; Hodgson, K.O.; Hedman, B.; Solomon, E.I.; /Stanford U., Chem. Dept. /Copenhagen U. /SLAC, SSRL /SUNY, Buffalo

2009-04-30

50

Gene cloning and heterologous expression of pyranose 2-oxidase ...  

Treesearch

Description: A pyranose 2-oxidase gene from the brown-rot basidiomycete ... in Escherichia coli yielding 15 U enzyme activity per ml of induced culture. ... pyranose 2-oxidase, wood-decaying fungi, fungi, biotechnology, industrial applications, ...

51

Terminal Oxidase Diversity and Function in "Metallosphaera yellowstonensis": Gene Expression and Protein Modeling Suggest Mechanisms of Fe(II) Oxidation in the Sulfolobales? †  

PubMed Central

“Metallosphaera yellowstonensis” is a thermoacidophilic archaeon isolated from Yellowstone National Park that is capable of autotrophic growth using Fe(II), elemental S, or pyrite as electron donors. Analysis of the draft genome sequence from M. yellowstonensis strain MK1 revealed seven different copies of heme copper oxidases (subunit I) in a total of five different terminal oxidase complexes, including doxBCEF, foxABCDEFGHIJ, soxABC, and the soxM supercomplex, as well as a novel hypothetical two-protein doxB-like polyferredoxin complex. Other genes found in M. yellowstonensis with possible roles in S and or Fe cycling include a thiosulfate oxidase (tqoAB), a sulfite oxidase (som), a cbsA cytochrome b558/566, several small blue copper proteins, and a novel gene sequence coding for a putative multicopper oxidase (Mco). Results from gene expression studies, including reverse transcriptase (RT) quantitative PCR (qPCR) of cultures grown autotrophically on either Fe(II), pyrite, or elemental S showed that the fox gene cluster and mco are highly expressed under conditions where Fe(II) is an electron donor. Metagenome sequence and gene expression studies of Fe-oxide mats confirmed the importance of fox genes (e.g., foxA and foxC) and mco under Fe(II)-oxidizing conditions. Protein modeling of FoxC suggests a novel lysine-lysine or lysine-arginine heme B binding domain, indicating that it is likely the cytochrome component of a heterodimer complex with foxG as a ferredoxin subunit. Analysis of mco shows that it encodes a novel multicopper blue protein with two plastocyanin type I copper domains that may play a role in the transfer of electrons within the Fox protein complex. An understanding of metabolic pathways involved in aerobic iron and sulfur oxidation in Sulfolobales has broad implications for understanding the evolution and niche diversification of these thermophiles as well as practical applications in fields such as bioleaching of trace metals from pyritic ores.

Kozubal, M. A.; Dlakic, M.; Macur, R. E.; Inskeep, W. P.

2011-01-01

52

Polymorphic variation in cytochrome oxidase subunit genes.  

PubMed

Cytochrome oxidase (COX) activity varies between individuals and low activities associate with Alzheimer's disease. Whether genetic heterogeneity influences function of this multimeric enzyme is unknown. To explore this we sequenced three mitochondrial DNA (mtDNA) and ten nuclear COX subunit genes from at least 50 individuals. 20% had non-synonymous mtDNA COX gene polymorphisms, 12% had a COX4I1 non-synonymous G to A transition, and other genes rarely contained non-synonymous polymorphisms. Frequent untranslated region (UTR) polymorphisms were seen in COX6A1, COX6B1, COX6C, and COX7A1; heterogeneity in a COX7A1 5' UTR Sp1 site was extensive. Synonymous polymorphisms were common and less frequent in the more conserved COX1 than the less conserved COX3, suggesting at least in mtDNA synonymous polymorphisms experience selection pressure and are not functionally silent. Compound gene variations occurred within individuals. To test whether variations could have functional consequences, we studied the COX4I1 G to A transition and an AGCCCC deletion in the COX7A1 5' UTR Sp1 site. Cells expressing the COX4I1 polymorphism had reduced COX Vmax activity. In reporter construct-transduced cells where green fluorescent protein expression depended on the COX7A1 Sp1 site, AGCCCC deletion reduced fluorescence. Our findings indicate COX subunit gene heterogeneity is pervasive and may mediate COX functional variation. PMID:20413852

Lu, Jianghua; Wang, Kaixuan; Rodova, Mariana; Esteves, Raquel; Berry, Diana; E, Lezi; Crafter, Adam; Barrett, Matthew; Cardoso, Sandra M; Onyango, Isaac; Parker, W Davis; Fontes, Joseph; Burns, Jeffrey M; Swerdlow, Russell H

2010-01-01

53

Characterization of the mouse protoporphyrinogen oxidase gene.  

PubMed

The murine protoporphyrinogen oxidase gene has been isolated, characterized and localized. The gene spans 4.2 kb, is comprised of 13 exons and 12 introns, and is located on chromosome 1 in band 1 H2. Analysis of 1.2 kb of the 5' upstream region revealed a promoter which is not GC rich and lacks any TATA boxes or initiator elements in the vicinity of the transcription start site. A variety of putative transcriptional element binding sequences were identified and gel shift assays support the presence of two GATA-1 sites near -760 bp as well as AP-1, AP-2, and Sp1 sites in the -1200 bp 5' flanking region. Luciferase reporter constructs transiently expressed in erythroid cell lines demonstrated erythroid-specific expression with the -1160 bp, but not with the -746 bp or -198 bp constructs. Expression in nonerythroid cells occurred maximally with -1160 bp, but was significant with -746 bp and absent with -198 bp. Expression of both housekeeping and erythroid-specific fusions in the transient expression systems was greatly decreased in the -5000 bp constructs suggesting the presence of repressor elements in the -1160 to -5000 bp region. PMID:11929049

Dailey, Tamara A; McManus, Julie F; Dailey, Harry A

2002-02-01

54

Cloning and expression of the potato alternative oxidase gene  

SciTech Connect

Mitochondria from 24-hour-aged potato slices possess an alternative path capacity and a 36kD protein not present in fresh potato mitochondria. This 36kD protein was identified by a monoclonal antibody against the Sauromatum guttatum alternative oxidase. These results suggest de novo synthesis of the 36kD protein during the aging process. To investigate this phenomenon, a clone containing a potato alternative oxidase gene was isolated from a cDNA library using the S. guttatum gene as a probe. This clone shows areas of high homology to the S. guttatum gene. Norther blots of RNA from fresh and 24-hour-aged potato slices are being probed with the potato gene to examine its expression in relation to the appearance of the 36kD protein.

Hiser, C.; McIntosh, L. (MSU-DOE Plant Research Laboratory, East Lansing, MI (USA) Michigan State Univ., East Lansing (USA))

1990-05-01

55

Lysyl Oxidase ( Lox ) Gene Deficiency Affects Osteoblastic Phenotype  

Microsoft Academic Search

Lysyl oxidase (LOX) catalyzes cross-linking of elastin and collagen, which is essential for the structural integrity and function\\u000a of bone tissue. The present study examined the role of Lox gene deficiency for the osteoblast phenotype in primary calvarial osteoblasts from E18.5 Lox knockout (Lox\\u000a \\u000a ?\\/?\\u000a ) and wild type (wt) (C57BL\\/6) mice. Next to Lox gene depletion, mRNA expression of

N. Pischon; J. M. Mäki; P. Weisshaupt; N. Heng; A. H. Palamakumbura; P. N’Guessan; A. Ding; R. Radlanski; H. Renz; T. A. L. J. J. Bronckers; J. Myllyharju; A. M. Kielbassa; B. M. Kleber; J.-P. Bernimoulin; P. C. Trackman

2009-01-01

56

Prokaryotic origins for the mitochondrial alternative oxidase and plastid terminal oxidase nuclear genes  

Microsoft Academic Search

The mitochondrial alternative oxidase is a diiron carboxylate quinol oxidase (Dox) found in plants and some fungi and protists, but not animals. The plastid terminal oxidase is distantly related to alternative oxidase and is most likely also a Dox protein. Database searches revealed that the ?-proteobacterium Novosphingobium aromaticivorans and the cyanobacteria Nostoc sp. PCC7120, Synechococcus sp. WH8102 and Prochlorococcus marinus

Patrick M Finnegan; Ann L Umbach; Jackie A Wilce

2003-01-01

57

Isolation of a Gene Encoding a Glycosylated Cytokinin Oxidase from Maize  

Microsoft Academic Search

The major cytokinin oxidase in immature maize kernels was purified to homogeneity. Selected tryptic peptides were used to design degenerate oligonucleotide primers for PCR isolation of a fragment of the oxidase gene. Hybridization of the PCR fragment to a maize genomic library allowed isolation of a full-length cytokinin oxidase gene (ckx1). The gene encodes a protein of approximately 57 kDa

Roy O. Morris; Kristin D. Bilyeu; James G. Laskey; Nordine N. Cheikh

1999-01-01

58

Molecular evolution of the polyamine oxidase gene family in Metazoa  

PubMed Central

Background Polyamine oxidase enzymes catalyze the oxidation of polyamines and acetylpolyamines. Since polyamines are basic regulators of cell growth and proliferation, their homeostasis is crucial for cell life. Members of the polyamine oxidase gene family have been identified in a wide variety of animals, including vertebrates, arthropodes, nematodes, placozoa, as well as in plants and fungi. Polyamine oxidases (PAOs) from yeast can oxidize spermine, N1-acetylspermine, and N1-acetylspermidine, however, in vertebrates two different enzymes, namely spermine oxidase (SMO) and acetylpolyamine oxidase (APAO), specifically catalyze the oxidation of spermine, and N1-acetylspermine/N1-acetylspermidine, respectively. Little is known about the molecular evolutionary history of these enzymes. However, since the yeast PAO is able to catalyze the oxidation of both acetylated and non acetylated polyamines, and in vertebrates these functions are addressed by two specialized polyamine oxidase subfamilies (APAO and SMO), it can be hypothesized an ancestral reference for the former enzyme from which the latter would have been derived. Results We analysed 36 SMO, 26 APAO, and 14 PAO homologue protein sequences from 54 taxa including various vertebrates and invertebrates. The analysis of the full-length sequences and the principal domains of vertebrate and invertebrate PAOs yielded consensus primary protein sequences for vertebrate SMOs and APAOs, and invertebrate PAOs. This analysis, coupled to molecular modeling techniques, also unveiled sequence regions that confer specific structural and functional properties, including substrate specificity, by the different PAO subfamilies. Molecular phylogenetic trees revealed a basal position of all the invertebrates PAO enzymes relative to vertebrate SMOs and APAOs. PAOs from insects constitute a monophyletic clade. Two PAO variants sampled in the amphioxus are basal to the dichotomy between two well supported monophyletic clades including, respectively, all the SMOs and APAOs from vertebrates. The two vertebrate monophyletic clades clustered strictly mirroring the organismal phylogeny of fishes, amphibians, reptiles, birds, and mammals. Evidences from comparative genomic analysis, structural evolution and functional divergence in a phylogenetic framework across Metazoa suggested an evolutionary scenario where the ancestor PAO coding sequence, present in invertebrates as an orthologous gene, has been duplicated in the vertebrate branch to originate the paralogous SMO and APAO genes. A further genome evolution event concerns the SMO gene of placental, but not marsupial and monotremate, mammals which increased its functional variation following an alternative splicing (AS) mechanism. Conclusions In this study the explicit integration in a phylogenomic framework of phylogenetic tree construction, structure prediction, and biochemical function data/prediction, allowed inferring the molecular evolutionary history of the PAO gene family and to disambiguate paralogous genes related by duplication event (SMO and APAO) and orthologous genes related by speciation events (PAOs, SMOs/APAOs). Further, while in vertebrates experimental data corroborate SMO and APAO molecular function predictions, in invertebrates the finding of a supported phylogenetic clusters of insect PAOs and the co-occurrence of two PAO variants in the amphioxus urgently claim the need for future structure-function studies.

2012-01-01

59

Genes for two multicopper proteins required for Fe(III) oxide reduction in Geobacter sulfurreducens have different expression patterns both in the subsurface and on energy-harvesting electrodes  

Microsoft Academic Search

Previous studies have shown that Geobacter sulfurreducens requires the outer-membrane, multicopper protein OmpB for Fe(III) oxide reduction. A homologue of OmpB, designated OmpC, which is 36% similar to OmpB, has been discovered in the G. sulfurreducens genome. Deletion of ompC inhibited reduction of insoluble, but not soluble Fe(III). Analysis of multiple Geobacter and Pelobacter genomes, as well as in situ

Dawn E. Holmes; Tunde Mester; Regina A. O'Neil; Lorrie A. Perpetua; M. Juliana Larrahondo; Richard Glaven; Manju L. Sharma; Joy E. Ward; Kelly P. Nevin; Derek R. Lovley

2008-01-01

60

Differential Expression of Alternative Oxidase Genes in Maize Mitochondrial Mutants  

PubMed Central

We have examined the expression of three alternative oxidase (aox) genes in two types of maize mitochondrial mutants. Nonchromosomal stripe (NCS) mutants carry mitochondrial DNA deletions that affect subunits of respiratory complexes and show constitutively defective growth. Cytoplasmic male-sterile (CMS) mutants have mitochondrial DNA rearrangements, but they are impaired for mitochondrial function only during anther development. In contrast to normal plants, which have very low levels of AOX, NCS mutants exhibit high expression of aox genes in all nonphotosynthetic tissues tested. The expression pattern is specific for each type of mitochondrial lesion: the NADH dehydrogenase–defective NCS2 mutant has high expression of aox2, whereas the cytochrome oxidase–defective NCS6 mutant predominantly expresses aox3. Similarly, aox2 and aox3 can be induced differentially in normal maize seedlings by specific inhibitors of these two respiratory complexes. Translation-defective NCS4 plants show induction of both aox2 and aox3. AOX2 and AOX3 proteins differ in their ability to be regulated by reversible dimerization. CMS mutants show relatively high levels of aox2 mRNAs in young tassels but none in ear shoots. Significant expression of aox1 is detected only in NCS and CMS tassels. The induction pattern of maize aox genes could serve as a selective marker for diverse mitochondrial defects.

Karpova, Olga V.; Kuzmin, Evgeny V.; Elthon, Thomas E.; Newton, Kathleen J.

2002-01-01

61

Phylogenetic Analysis of Six-Domain Multi-Copper Blue Proteins  

PubMed Central

Multicopper blue proteins, composed of several repetitive copper-binding domains similar to one-domain cupredoxin-like proteins, were found in almost all organisms. They are classified into the three different groups, based on their two-, three- or six-domain organization. We found orthologs of chordate six-domain copper-binding proteins in animals, plants, bacteria and archea. The phylogenetic analysis of 183 multicopper blue proteins and their copper-binding sites comparison make us think that all the modern six-domain blue proteins have originated from the common ancestral six-domain protein in the process of gene duplication and copper-binding sites loss as a result of amino acid substitutions.

Vasin, Andrey; Klotchenko, Sergey; Puchkova, Ludmila

2013-01-01

62

Lysyl oxidase (lox) gene deficiency affects osteoblastic phenotype.  

PubMed

Lysyl oxidase (LOX) catalyzes cross-linking of elastin and collagen, which is essential for the structural integrity and function of bone tissue. The present study examined the role of Lox gene deficiency for the osteoblast phenotype in primary calvarial osteoblasts from E18.5 Lox knockout (Lox ( -/- )) and wild type (wt) (C57BL/6) mice. Next to Lox gene depletion, mRNA expression of Lox isoforms, LOXL1-4, was significantly downregulated in Lox ( -/- ) bone tissue. A significant decrease of DNA synthesis of Lox ( -/- ) osteoblasts compared to wt was found. Early stages of osteoblastic apoptosis studied by annexin-V binding as well as later stages of DNA fragmentation were not affected. However, mineral nodule formation and osteoblastic differentiation were markedly decreased, as revealed by significant downregulation of osteoblastic markers, type I collagen, bone sialoprotein, and Runx2/Cbfa1. PMID:19458888

Pischon, N; Mäki, J M; Weisshaupt, P; Heng, N; Palamakumbura, A H; N'Guessan, P; Ding, A; Radlanski, R; Renz, H; Bronckers, T A L J J; Myllyharju, J; Kielbassa, A M; Kleber, B M; Bernimoulin, J-P; Trackman, P C

2009-05-21

63

Lysyl Oxidase (Lox) Gene Deficiency Affects Osteoblastic Phenotype  

PubMed Central

Lysyl oxidase (LOX) catalyzes cross-linking of elastin and collagen, which is essential for structural integrity and function of bone tissue. The present study examined the role of Lox gene deficiency for the osteoblast phenotype in primary calvarial osteoblasts from E18.5 Lox knockout (Lox-/-) and wild type (wt) (C57 BL/6) mice. Next to Lox gene depletion, mRNA expression of Lox isoforms, LOXL1-4, was significantly down-regulated in Lox-/- bone tissue. A significant decrease of DNA synthesis of Lox-/- osteoblasts compared to wt was found. Early stages of osteoblastic apoptosis studied by Annexin-V binding as well as later stages of DNA fragmentation were not affected. However, mineral nodule formation and osteoblastic differentiation were markedly decreased, as revealed by significant down-regulation of osteoblastic markers, type I collagen, BSP and Runx2/Cbfa1.

Pischon, N.; Maki, J. M.; Weisshaupt, P.; Heng, N.; Palamakumbura, A. H.; N'Guessan, P.; Ding, A.; Radlanski, R.; Renz, H.; Bronckers, T. A. L. J. J.; Myllyharju, J.; Kielbassa, A.; Kleber, B. M.; Bernimoulin, J.-P.; Trackman, P.C.

2010-01-01

64

Differential and wound-inducible expression of 1-aminocylopropane-1-carboxylate oxidase genes in sunflower seedlings  

Microsoft Academic Search

In an effort towards understanding the biochemical properties and physiological functions of 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase homologues, we have isolated three ACC oxidase clones from sunflower (Helianthus annuus) seedlings. ACCO1 is a cDNA clone while ACCO2 and ACCO3 and reverse transcriptase-polymerase chain reaction clones. Southern analysis indicated the existence of at least three members in the sunflower ACC oxidase gene

Jin-Hao Liu; Siew Hwee Lee-Tamon; David M. Reid

1997-01-01

65

Human monoamine oxidase A gene determines levels of enzyme activity.  

PubMed Central

Monoamine oxidase (MAO) is a critical enzyme in the degradative deamination of biogenic amines throughout the body. Two biochemically distinct forms of the enzyme, A and B, are encoded in separate genes on the human X chromosome. In these studies we investigated the role of the structural gene for MAO-A in determining levels of activity in humans, as measured in cultured skin fibroblasts. The coding sequence of the mRNA for MAO-A was determined by first-strand cDNA synthesis, PCR amplification, and direct dideoxy sequencing. Two single-basepair substitutions were observed in cDNAs from cells with a 30-fold difference in activity levels. These two substitutions were in the third base of a triplet codon and hence did not affect the deduced amino acid sequence but did affect the presence or absence of restriction-enzyme sites for EcoRV and Fnu4HI, which could be elucidated on PCR fragments derived from genomic DNA or cDNAs. A third polymorphism for MspI in the noncoding region of the MAOA gene was also evaluated by Southern blot analysis using genomic DNA. Statistically significant associations were observed between the alleles for MAOA and levels of MAO activity in human male fibroblast lines. This association indicates that the MAOA gene itself is a major determinant of activity levels, apparently, in part, through noncoding, regulatory elements. Images Figure 3 Figure 4 Figure 5

Hotamisligil, G S; Breakefield, X O

1991-01-01

66

Gene cloning of the maoA gene and overproduction of a soluble monoamine oxidase from Klebsiella aerogenes  

Microsoft Academic Search

We cloned the structural gene for monoamine oxidase (maoA) from Klebsiella aerogenes into a pKI212 vector in an maoA mutant strain of K. aerogenes. Deletion analysis and complementation tests of the recombinant plasmid showed that the maoA gene was located entirely within a 4.1-kb segment. In an maoA mutant strain harbouring the cloned maoA gene, synthesis of monoamine oxidase was

Hiroyuki Sugino; Kaname Ishibashi; Masashi Sakaue; Mitsuo Yamashita; Yoshikatsu Murooka

1991-01-01

67

Variegate porphyria: identification of a nonsense mutation in the protoporphyrinogen oxidase gene.  

PubMed

The porphyrias are disorders of porphyrin metabolism that result from inherited or acquired aberrations in the control of the heme biosynthetic pathway. Variegate porphyria is characterized by a partial reduction in the activity of protoporphyrinogen oxidase. In this study, we identified the first nonsense mutation in a family with variegate porphyria. The mutation consisted of a previously unreported G-to-T transversion in exon 5 of the protoporphyrinogen oxidase gene, resulting in the substitution of glutamic acid by a nonsense codon, designated E133X. Our investigation establishes that a nonsense mutation in the protoporphyrinogen oxidase gene is the underlying mutation in this family with variegate porphyria. PMID:9540990

Frank, J; Jugert, F K; Kalka, K; Goerz, G; Merk, H F; Christiano, A M

1998-04-01

68

Isolation and Characterization of the Aldehyde Oxidase2 Gene from Arachis hypogaea L  

Microsoft Academic Search

An aldehyde oxidase gene, designated as aldehyde oxidase2 (AhAO2), was cloned from Arachis hypogaea L. The gene contained a 4,050-bp open reading frame that encoded a putative protein of 1,350 amino acids. The deduced amino\\u000a acid sequence showed high identity with other plant AOs. The organ-specific expression pattern of AhAO2 has been examined, which indicates its dominant expression in leaves

Lixia Yang; Jianhua Liang; Wenling Zhou; Liangchen Su; Biyu Zhang; Ling Li

2011-01-01

69

Identification, characterization, and localization of the human lysyl oxidase-related gene  

Microsoft Academic Search

Lysyl oxidase (lox) initiates the formation of inter- and intra-strand covalent crosslinks of mature collagen and elastin in connective tissue. The lox gene has been cloned and mapped to human chromosome 5q23.3-31.2. The lysyl oxidase gene is approximately 15 kb in size and consists of seven exons. Lox mRNA is expressed at high levels in rat aorta and lung, and

K. S. Carlisle; J. K. Mellott; T. P. Yang

1994-01-01

70

Suppressed expression of the apoplastic ascorbate oxidase gene increases salt tolerance in tobacco and Arabidopsis plants  

Microsoft Academic Search

Transgenic tobacco plants expressing the ascorbate oxidase (AAO) gene in sense and antisense orienta- tions, and an Arabidopsis mutant in which the T-DNA was inserted into a putative AAO gene, were used to examine the potential roles of AAO for salt-stress tolerance in plants. AAO activities in the transgenic tobacco plants expressing the gene in sense and anti- sense orientations

Atsuko Yamamoto; Nazmul H. Bhuiyan; Rungaroon Waditee; Yoshito Tanaka; Muneharu Esaka; Kazuko Oba; Teruhiro Takabe

2005-01-01

71

POST-TRANSCRIPTIONAL SILENCING OF POLYPHENOL OXIDASE GENE EXPRESSION IN RED CLOVER  

Technology Transfer Automated Retrieval System (TEKTRAN)

Post-transcriptional gene silencing (PTGS) by transformation of anti-sense, co-suppression, or hairpin RNA-producing constructs is a powerful tool to analyze in vivo gene function in plants. We are using this approach to reduce polyphenol oxidase (PPO) gene expression in red clover in order to bett...

72

Gene cloning and heterologous expression of pyranose 2-oxidase from the brown-rot fungus, Gloeophyllum trabeum  

Microsoft Academic Search

A pyranose 2-oxidase gene from the brown-rot basidiomycete Gloeophyllum trabeum was isolated using homology-based degenerate PCR. The gene structure was determined and compared to that of several pyranose\\u000a 2-oxidases cloned from white-rot fungi. The G. trabeum pyranose 2-oxidase gene consists of 16 coding exons with canonical promoter CAAT and TATA elements in the 5?UTR. The corresponding\\u000a G. trabeum cDNA was

Diane Dietrich; Casey Crooks

2009-01-01

73

Common polymorphisms in human lysyl oxidase genes are not associated with the adolescent idiopathic scoliosis phenotype  

Microsoft Academic Search

Background  Although adolescent idiopathic scoliosis affects approximately 3% of adolescents, the genetic contributions have proven difficult\\u000a to identify. Work in model organisms, including zebrafish, chickens, and mice, has implicated the lysyl oxidase family of\\u000a enzymes in the development of scoliosis. We hypothesized that common polymorphisms in the five human lysyl oxidase genes (LOX, LOXL1, LOXL2, LOXL3, and LOXL4) may be associated

Tracy L McGregor; Christina A Gurnett; Matthew B Dobbs; Carol A Wise; Jose A Morcuende; Thomas M Morgan; Ramkumar Menon; Louis J Muglia

2011-01-01

74

Transformation of Japanese persimmon (Diospyros kaki Thunb.) with a bacterial gene for choline oxidase  

Microsoft Academic Search

This report describes the first successful genetic engineering of tolerance to salt in an agriculturally important species of woody plants by Agrobacterium-mediated transformation with the codA gene of Arthrobacter globiformis. This gene encodes choline oxidase, which catalyzes the oxidation of choline to glycinebetaine. The binary plasmid vector pGC95.091, containing a kanamycin-resistance gene (nptII), a gene for ß-glucuronidase (gusA) and the

Mei Gao; Atsushi Sakamoto; Keisuke Miura; Norio Murata; Akira Sugiura; Ryutaro Tao

2000-01-01

75

Cloning and expression of a Streptomyces cholesterol oxidase gene in Streptomyces lividans with plasmid pIJ702.  

PubMed Central

The cholesterol oxidase gene (cho) of Streptomyces sp. was cloned into Streptomyces lividans with the vector pIJ702. Deletion analysis of the recombinant plasmid showed that entire coding sequence of the cho gene was located within a 2.5-kilobase segment of the chromosomal DNA obtained from the cholesterol oxidase-producing strain. When cloned cells of S. lividans were grown in an appropriate medium, the cells produced severalfold more cholesterol oxidase extracellularly than did the producing strain.

Murooka, Y; Ishizaki, T; Nimi, O; Maekawa, N

1986-01-01

76

The expression of lysyl-oxidase gene family members in myeloproliferative neoplasms.  

PubMed

Myeloproliferative neoplasms (MPNs) are malignant disorders originating from clonal expansion of a single neoplastic stem cell and characteristically show an increase in bone marrow reticulin fibers. Lysyl oxidases (LOXs) are copper-dependent amine oxidases that play a critical role in the biogenesis of connective tissue by crosslinking extracellular matrix proteins, collagen and elastin. Expression of LOX gene family members is increased in disorders associated with increased fibrosis. To evaluate involvement of LOX gene family in various MPNs. In-situ hybridization was used to detect Lysyl-Oxidase family members in bone marrow biopsies from patients with different MPNs. We compared normal bone marrows and those from patients with polycythemia vera, essential thrombocythemia, chronic myeloid leukemia, and primary myelofibrosis (PMF). Serum levels of lysyl-oxidase from patients with PMF and healthy controls were also examined. LOX gene family was not detected in normal bone marrows. All members of the LOX gene family were over expressed in PMF. In other MPNs a differential pattern of expression was observed. Differences in gene expression were statistically significant (P < 0.010). The medianserum LOX levels in normal controls was 28.4 ± 2.5 ng\\ml and 44.6 ± 9.44 ng\\ml in PMF (P = 0.02). The varying pattern of expression of LOX genes may reflect differences in the pathophysiology of bone marrow fibrosis in these MPNs. These observations could be used as the basis for future targeted therapy directed against bone marrow fibrosis. PMID:23494965

Tadmor, T; Bejar, J; Attias, D; Mischenko, E; Sabo, E; Neufeld, G; Vadasz, Z

2013-03-12

77

Monoamine oxidases A and B gene polymorphisms in migraine patients  

Microsoft Academic Search

Abnormal cortical activity and brainstem functioning are considered the possible etiopathogenetic factors of migraine. Monoamine oxidase A and B (MAO-A and -B) regulate the levels of monoamine neurotransmitters, so changes in their activity could participate in migraine pathogenesis. We have investigated the possible association of MAO-A and -B alleles and haplotypes with two common types of migraine, i.e. migraine without

Vedrana Filic; Anton Vladic; Jasminka Stefulj; Lipa Cicin-Sain; Melita Balija; Zvonimir Sucic; Branimir Jernej

2005-01-01

78

Pistil-Specific and Ethylene-Regulated Expression of 1-Aminocyclopropane-1-Carboxylate Oxidase Genes in Petunia Flowers.  

PubMed Central

The differential expression of the petunia 1-aminocyclopropane-1-carboxylate (ACC) oxidase gene family during flower development and senescence was investigated. ACC oxidase catalyzes the conversion of ACC to ethylene. The increase in ethylene production by petunia corollas during senescence was preceded by increased ACC oxidase mRNA and enzyme activity. Treatment of flowers with ethylene led to an increase in ethylene production, ACC oxidase mRNA, and ACC oxidase activity in corollas. In contrast, leaves did not exhibit increased ethylene production or ACC oxidase expression in response to ethylene. Gene-specific probes revealed that the ACO1 gene was expressed specifically in senescing corollas and in other floral organs following exposure to ethylene. The ACO3 and ACO4 genes were specifically expressed in developing pistil tissue. In situ hybridization experiments revealed that ACC oxidase mRNAs were specifically localized to the secretory cells of the stigma and the connective tissue of the receptacle, including the nectaries. Treatment of flower buds with ethylene led to patterns of ACC oxidase gene expression spatially distinct from the patterns observed during development. The timing and tissue specificity of ACC oxidase expression during pistil development were paralleled by physiological processes associated with reproduction, including nectar secretion, accumulation of stigmatic exudate, and development of the self-incompatible response.

Tang, X; Gomes, A; Bhatia, A; Woodson, WR

1994-01-01

79

Differential Expression and Turnover of the Tomato Polyphenol Oxidase Gene Family during Vegetative and Reproductive Development  

Microsoft Academic Search

Polyphenol oxidases (PPOs) are encoded by a highly conserved, seven-member gene family clustered within a 165-kb locus on chromosome 8 of tomato (Lycopersicon esculentum). Using gene- specific probes capable of differentiating between PPO A\\/C, PPO B, PPO D, and PPO E\\/F, we examined the spatial and temporal ex- pression of this gene family during vegetative and reproductive development. RNA blots

Piyada Thipyapong; Daniel M. Joel; John C. Steffens

80

Structure and function of cytokinin oxidase\\/dehydrogenase genes of maize, rice, Arabidopsis and other species  

Microsoft Academic Search

Cytokinin oxidases\\/dehydrogenases (CKX) catalyze the irreversible degradation of the cytokinins isopentenyladenine, zeatin,\\u000a and their ribosides in a single enzymatic step by oxidative side chain cleavage. To date the sequences of 17 fully annotated CKX genes are known, including two prokaryotic genes. The CKX gene families of Arabidopsis thaliana and rice comprise seven and at least ten members, respectively. The main

Thomas Schmülling; Tomáš Werner; Michael Riefler; Eva Krupková; Isabel Bartrina y Manns

2003-01-01

81

Measurement of copepod predation on nauplii using qPCR of the cytochrome oxidase I gene  

Microsoft Academic Search

A method to directly measure predation rates by older stage copepods upon copepod nauplii using species-specific primers for\\u000a the mitochondrial cytochrome oxidase subunit one gene (mtCOI) and real-time quantitative PCR (qPCR) was developed. The general\\u000a approach is to determine the mtCOI gene copy number of an individual prey organism and the copy number of the same gene in\\u000a the stomachs

Edward G. Durbin; Maria C. Casas; Tatiana A. Rynearson; David C. Smith

2008-01-01

82

Digenic inheritance of mutations in the coproporphyrinogen oxidase and protoporphyrinogen oxidase genes in a unique type of porphyria.  

PubMed

The simultaneous dysfunction of two enzymes within the heme biosynthetic pathway in a single patient is rare. Not more than 15 cases have been reported. A woman with a transient episode of severe photosensitivity showed a biochemical porphyrin profile suggestive of hereditary coproporphyria (HCP), whereas some of her relatives had a profile that was suggestive of variegate porphyria (VP). HCP and VP result from a partial enzymatic deficiency of coproporphyrinogen oxidase (CPOX) and protoporphyrinogen oxidase (PPOX), respectively. DNA analysis in the index patient revealed mutations in both the CPOX and PPOX genes, designated as c.557-15C>G and c.1289dupT, respectively. The CPOX mutation leads to a cryptic splice site resulting in retention of 14 nucleotides from intron 1 in the mRNA transcript. Both mutations encode null alleles and were associated with nonsense-mediated mRNA decay. Given the digenic inheritance of these null mutations, coupled with the fact that both HCP and VP can manifest with life-threatening acute neurovisceral attacks, the unusual aspect of this case is a relatively mild clinical phenotype restricted to dermal photosensitivity. PMID:21734717

van Tuyll van Serooskerken, Anne Moniek; de Rooij, Felix W; Edixhoven, Annie; Bladergroen, Reno S; Baron, Jens M; Joussen, Sylvia; Merk, Hans F; Steijlen, Peter M; Poblete-Gutiérrez, Pamela; te Velde, Kornelis; Wilson, J H Paul; Koole, Rita H; van Geel, Michel; Frank, Jorge

2011-07-07

83

Deletion of the gene for subunit III leads to defective assembly of bacterial cytochrome oxidase.  

PubMed Central

COIII is one of the major subunits in the mitochondrial and a bacterial cytochrome c oxidase, cytochrome aa3. It does not contain any of the enzyme's redox-active metal centres and can be removed from the enzyme without major changes in its established functions. We have deleted the COIII gene from Paracoccus denitrificans. The mutant still expresses spectroscopically detectable enzyme almost as the wild-type, but its cytochrome c oxidase activity is much lower. From 50 to 80% of cytochrome a is reduced and its absorption maximum is 2-3 nm blue-shifted. The EPR signal of ferric cytochrome a is heterogeneous indicating the presence of multiple cytochrome a species. Proteolysis of the membrane-bound oxidase shows new cleavage sites both in COI and COII. DEAE-chromatography of solubilized enzyme yields fractions that contain a COI + COII complex and in addition haem-binding, free COI as well as free COII. The mutant phenotype can be complemented by introducing the COIII gene back to cells in a plasmid vector. We conclude that cytochrome oxidase assembles inefficiently in the absence of COIII and that this subunit may facilitate a late step in the assembly. The different oxidase species in the mutant represent either accumulating intermediates of the assembly pathway or dissociation products of a labile COI + COII complex and its conformational variants. Images

Haltia, T; Finel, M; Harms, N; Nakari, T; Raitio, M; Wikstrom, M; Saraste, M

1989-01-01

84

Association analysis of monoamine oxidase A gene and bipolar affective disorder in Han Chinese  

Microsoft Academic Search

BACKGROUND: Monoamine oxidase A (MAOA) is a mitochondrial enzyme involved in degrading several different biological amines, including serotonin. Although several pieces of evidence suggested that MAOA is important in the etiology of bipolar affective disorder (BPD), associations for markers of the MAOA gene with BPD were not conclusive and the association has not been investigated in Taiwanese population. This study

Yi-Mei J Lin; Fabian Davamani; Wei-Chih Yang; Te-Jen Lai; H Sunny Sun

2008-01-01

85

Monoamine Oxidase a Promoter Gene Associated with Problem Behavior in Adults with Intellectual/Developmental Disabilities  

ERIC Educational Resources Information Center

|A functional polymorphism in the promoter of the gene encoding monoamine oxidase A has been associated with problem behavior in various populations. We examined the association of MAOA alleles in adult males with intellectual/developmental disabilities with and without established histories of problem behavior. These data were compared with a…

May, Michael E.; Srour, Ali; Hedges, Lora K.; Lightfoot, David A.; Phillips, John A., III; Blakely, Randy D.; Kennedy, Craig H.

2009-01-01

86

Different effects on ACC oxidase gene silencing triggered by RNA interference in transgenic tomato  

Microsoft Academic Search

RNA interference (RNAi) is a potent trigger for specific gene silencing of expression in a number of organisms and is an efficient way of shutting down gene expression. 1-Aminocyclopropane-1-carboxylate (ACC) oxidase catalyzes the oxidation of ACC to ethylene, a plant growth regulator that plays an important role in the tomato ripening process. In this research, to produce double-stranded (ds)RNA of

Ai-Sheng Xiong; Quan-Hong Yao; Ri-He Peng; Xian Li; Pei-Lai Han; Hui-Qin Fan

2005-01-01

87

The Effects of Serotonin Transporter Promoter and Monoamine Oxidase A Gene Polymorphisms on Trait Emotional Intelligence  

Microsoft Academic Search

Objective: The purpose of this study was to evaluate the influences of major serotonin-related genetic variants of the serotonin transporter-linked promoter region (5-HTTLPR), tryptophan hydroxylase 1 gene (TPH1) and monoamine oxidase A gene (MAOA-EcoRV) on trait emotional intelligence (EI). Methods: The Trait Meta-Mood Scale (TMMS) measuring trait EI and genotyping were performed in 336 healthy Korean college students (204 males,

Se Joo Kim; Jee In Kang; Kee Namkoong; Dong-Ho Song

2011-01-01

88

Expression of a Bacillus subtilis protoporphyrinogen oxidase gene in rice plants reduces sensitivity to peroxidizing herbicides  

Microsoft Academic Search

Protoporphyrinogen oxidase (Protox) in the porphyrin pathway is the target site of the peroxidizing herbicides such as carfentrazone-ethyl and oxyfluorfen. In an attempt to develop herbicide-resistant plants, transgenic rice plants were generated via expression of herbicide-insensitive Bacillus subtilis Protox gene fused to the transit sequence for targeting to the plastid using Agrobacterium-mediated gene transformation. Homozygous transgenic rice lines of T3

Y. I. Kuk; H. J. Lee; J. S. Chung; K. M. Kim; S. B. Lee; S. B. Ha; K. Back; J. O. Guh

2005-01-01

89

Isolation and characterization of structural genes for human and mouse cytochrome c oxidase subunit VIIaH  

Microsoft Academic Search

The cytochrome c oxidase enzyme in mammals is composed of thirteen subunits, most of which are encoded by nuclear genes. Some of these exist as heart\\/skeletal muscle-specific variants (isoforms), whereas other isoforms are expressed ubiquitously. In this thesis we report for the first time the presence and developmental expression of the heart isoform of Cytochrome c oxidase (COX) subunit VIIa

Saied Ali Jaradat

1998-01-01

90

Mitochondrial electron transport regulation of nuclear gene expression. Studies with the alternative oxidase gene of tobacco.  

PubMed Central

We have isolated a cDNA representing the tobacco (Nicotiana tabacum L. cv Bright Yellow) nuclear gene Aox1, which encodes the alternative oxidase of plant mitochondria. The clone contains the complete coding region (1059 base pairs) of a precursor protein of 353 amino acids with a calculated molecular mass of 39.8 kD. A putative transit peptide contains common signals believed to be important for import and processing of mitochondrially localized proteins. We have studied changes in Aox1 gene expression in tobacco in response to changes in cytochrome pathway activity. Inhibition of the cytochrome pathway by antimycin A resulted in a rapid and dramatic accumulation of Aox1 mRNA, whereas the level of mRNAs encoding two proteins of the cytochrome pathway did not change appreciably. This was accompanied by a dramatic increase in alternative pathway capacity and engagement in whole cells. Respiration under these conditions was unaffected by the uncoupler p-trifluoromethoxycarbonylcyanide (FCCP). When inhibition of the cytochrome pathway was relieved, levels of Aox1 mRNA returned to control levels, alternative pathway capacity and engagement declined, and respiration could once again be stimulated by FCCP. The results show that a mechanism involving changes in Aox1 gene expression exists whereby the capacity of the alternative pathway can be adjusted in response to changes in the activity of the cytochrome pathway.

Vanlerberghe, G C; McIntosh, L

1994-01-01

91

Expression of Phanerochaete chrysosporium genes encoding lignin peroxidases, manganese peroxidases, and glyoxal oxidase in wood  

Microsoft Academic Search

Lignin depolymerization is catalyzed by extracellular enzymes of white rot basidiomycetes such as Phanerochaete chrysosporium. Major components of this system include lignin peroxidases, manganese-dependent lignin peroxidases, and a peroxide-generating enzyme, glyoxal oxidase. Expression of Phanerochaete chrysosporium genes encoding ligninolytic enzymes was assessed in wood. Poly(A) RNA was extracted from colonized wood chips by magnetic capture, and specific transcripts were quantified

BERNARD J. H. JANSE; JILL GASKELL; D. Cullen; M. Akhtar

1998-01-01

92

Molecular cloning and characterization of the polyphenol oxidase gene from sweetpotato  

Microsoft Academic Search

Polyphenol oxidase is the enzyme responsible for enzymatic browning in sweetpotato that decreases the commercial value of\\u000a sweetpotato products. Here we reported the cloning and characterization of a new cDNA encoding PPO from sweetpotato, designated\\u000a as IbPPO (GeneBank accession number: AY822711). The full-length cDNA of IbPPO is 1984 bp with a 1767 bp open reading frame (ORF) encoding a 588

Z. Liao; R. Chen; M. Chen; Y. Yang; Y. Fu; Q. Zhang; X. Lan

2006-01-01

93

Thyroid Oxidase (THOX2) Gene Expression in the Rat Thyroid Cell Line FRTL-5  

Microsoft Academic Search

A cDNA encoding an NADPH oxidase flavoprotein was isolated from the rat thyroid gland. The predicted 1517-residue polypeptide was 82.5% identical to the human THOX2\\/DUOX2 and 74% similar to THOX1\\/DUOX1. Rat THOX2 lacks a stretch of 30 residues, corresponding to one exon in the human gene sequence. THOX2 mRNA was found to be expressed in cultured FRTL-5 cells. The level

Corinne Dupuy; Martine Pomerance; Renée Ohayon; Marie-Sophie Noël-Hudson; Danielle Dème; Mokhtar Chaaraoui; Jacques Francon; Alain Virion

2000-01-01

94

PapilioPhylogeny Based on Mitochondrial Cytochrome Oxidase I and II Genes  

Microsoft Academic Search

Butterflies of the genusPapiliohave served as the basis for numerous studies in insect physiology, genetics, and ecology. However, phylogenetic work on relationships among major lineages in the genus has been limited and inconclusive. We have sequenced 2.3 kb of DNA from the mitochondrial cytochrome oxidase I and II genes (COI and COII) for 23Papiliotaxa and two outgroups,Pachliopta neptunusandEurytides marcellus,in order

Michael S. Caterino; Felix A. H. Sperling

1999-01-01

95

Molecular basis of variegate porphyria: a de novo insertion mutation in the protoporphyrinogen oxidase gene  

Microsoft Academic Search

The porphyrias are disorders that result from the inherited or acquired dysregulation of one of the eight enzymes in the\\u000a heme biosynthetic pathway. Variegate porphyria (VP) is characterized by deficiencies in protoporphyrinogen oxidase (PPO) and\\u000a has recently been genetically linked (Z = 6.62) to the PPO gene on chromosome 1q21. In this study, we have identified two sequence variants in

HaMut Lam; Laryssa Dragan; Hui C. Tsou; Hans Merk; Monica Peacocke; Günter Goerz; Shigeru Sassa; Maureen Poh-Fitzpatrick; David R. Bickers; Angela M. Christiano

1996-01-01

96

D-Amino-acid oxidase gene from Rhodotorula gracilis (Rhodosporidium toruloides) ATCC 26217  

Microsoft Academic Search

The complete nucleotide sequence of the DA07 gene encoding D-amino-acid oxidase (DAAO) in the yeast Rhodotorula gracilis (Rhodosporidium toruloides) ATCC 26217 has been determined. The primary structure of DAAO was deduced from the nucleotide sequence of a cDNA clone that covered the entire amino acid coding sequence. Comparison of cDNA and genomic sequences of DA07 revealed the presence of five

Jorge Alonso; J. L Barredo; Bruno Diez; E. Mellado; Francisco Salto; Jose L. Garcia; Estrella Cortes

1998-01-01

97

Overexpression of a Gene Encoding Hydrogen Peroxide-Generating Oxalate Oxidase Evokes Defense Responses in Sunflower  

Microsoft Academic Search

Oxalate oxidase (OXO) converts oxalic acid (OA) and O2 to CO2 and hydrogen peroxide (H2O2), and acts as a source of H2O2 in certain plant-pathogen interactions. To determine if the H2O2 produced by OXO can function as a messenger for activation of defense genes and if OXO can confer resistance against an OA-producing pathogen, we analyzed transgenic sunflower (Helianthus annuus

Xu Hu; Dennis L. Bidney; Nasser Yalpani; Jonathan P. Duvick; Oswald Crasta; Otto Folkerts; Guihua Lu

2003-01-01

98

Cloning and In Situ Expression Studies of the Hydrogenobaculum Arsenite Oxidase Genes?  

PubMed Central

Novel arsenite [As(III)] oxidase structural genes (aoxAB) were cloned from Hydrogenobaculum bacteria isolated from an acidic geothermal spring. Reverse transcriptase PCR demonstrated expression throughout the outflow channel, and the aoxB cDNA clones exhibited distribution patterns relative to the physicochemical gradients in the spring. Microelectrode analyses provided evidence of quantitative As(III) transformation within the microbial mat.

Clingenpeel, Scott R.; D'Imperio, Seth; Oduro, Harry; Druschel, Greg K.; McDermott, Timothy R.

2009-01-01

99

Molecular cloning and biological activity of a novel lysyl oxidase-related gene expressed in cartilage.  

PubMed

We cloned a cDNA encoding a novel lysyl oxidase-related protein, named LOXC, by suppression subtractive hybridization between differentiated and calcified ATDC5 cells, a clonal mouse chondrogenic EC cell line. The deduced amino acid sequence of mouse LOXC consists of 757 amino acids and shows 50% identity with that of mouse lysyl oxidase. Northern blot analysis showed a distinct hybridization band of 5.4 kilobases, and Western blot analysis showed an immunoreactive band at 82 kilodaltons. Expression of LOXC mRNA was detected in osteoblastic MC3T3-E1 cells and embryonic fibroblast C3H10T1/2 cells, whereas none of NIH3T3 fibroblasts and myoblastic C2C12 cells expressed LOXC mRNA in vitro. Moreover, the LOXC mRNA and protein levels dramatically increased throughout a process of chondrogenic differentiation in ATDC5 cells. In vivo, LOXC gene expression was localized in hypertrophic and calcified chondrocytes of growth plates in adult mice. The conditioned media of COS-7 cells transfected with the full-length LOXC cDNA showed the lysyl oxidase activity in both type I and type II collagens derived from chick embryos, and these activities of LOXC were inhibited by beta-aminopropionitrile, a specific inhibitor of lysyl oxidase. Our data indicate that LOXC is expressed in cartilage in vivo and modulates the formation of a collagenous extracellular matrix. PMID:11292829

Ito, H; Akiyama, H; Iguchi, H; Iyama, K; Miyamoto, M; Ohsawa, K; Nakamura, T

2001-04-05

100

Common polymorphisms in human lysyl oxidase genes are not associated with the adolescent idiopathic scoliosis phenotype  

PubMed Central

Background Although adolescent idiopathic scoliosis affects approximately 3% of adolescents, the genetic contributions have proven difficult to identify. Work in model organisms, including zebrafish, chickens, and mice, has implicated the lysyl oxidase family of enzymes in the development of scoliosis. We hypothesized that common polymorphisms in the five human lysyl oxidase genes (LOX, LOXL1, LOXL2, LOXL3, and LOXL4) may be associated with the phenotype of adolescent idiopathic scoliosis. Methods This was a case-control genetic association study. A total of 112 coding and tag SNPs in LOX, LOXL1, LOXL2, LOXL3, and LOXL4 were genotyped in a discovery cohort of 138 cases and 411 controls. Genotypes were tested for association with adolescent idiopathic scoliosis by logistic regression with a two degree of freedom genotypic model and gender as a covariate. Fourteen SNPs with p < 0.1 in the discovery phase were genotyped in an independent replication cohort of 400 cases and 506 controls. Results No evidence for significant association was found between coding or tag SNPs in LOX, LOXL1, LOXL2, LOXL3, and LOXL4 and the phenotype of adolescent idiopathic scoliosis. Conclusions Despite suggestive evidence in model organisms, common variants and known coding SNPs in the five human lysyl oxidase genes do not confer increased genotypic risk for adolescent idiopathic scoliosis. The above methodology does not address rare variants or individually private mutations in these genes, and future research may focus on this area.

2011-01-01

101

Cytochrome c oxidase genes required for nitrogenase activity and diazotrophic growth in Anabaena sp. PCC 7120.  

PubMed

N2 fixation is an O2-sensitive process and some filamentous diazotrophic cyanobacteria that grow performing oxygenic photosynthesis confine their N2 fixation machinery to heterocysts, specialized cells that maintain a reducing environment adequate for N2 fixation. Respiration is thought to contribute to the diazotrophic metabolism of heterocysts and the genome of the heterocyst-forming cyanobacterium Anabaena sp. PCC 7120 bears three gene clusters putatively encoding cytochrome c oxidases. Transcript analysis of these cox gene clusters through RNA/DNA hybridization identified two cox operons, cox2 and cox3, that are induced after nitrogen step-down in an NtcA- and HetR-dependent manner and appear to be expressed specifically in heterocysts. In contrast, cox1 was expressed only in vegetative cells. Expression of cox2 and cox3 occurred at an intermediate stage (about 9 h) during the process of heterocyst development following nitrogen step-down. Inactivation of genes in the two inducible cox operons, but not separately in either of them, strongly reduced nitrogenase activity and prevented diazotrophic growth in aerobic conditions. These results show that the nitrogen-regulated cytochrome c oxidase-type respiratory terminal oxidases Cox2 and Cox3 are essential for heterocyst function in Anabaena sp. PCC 7120. PMID:12603731

Valladares, Ana; Herrero, Antonia; Pils, Dietmar; Schmetterer, Georg; Flores, Enrique

2003-03-01

102

Regulation of NADPH oxidase gene expression with PKA and cytokine IL-4 in neurons and microglia.  

PubMed

Neuronal excitation is mediated by the activation of NMDA receptor and associated with the formation of reactive oxygen species due to the activation of NADPH oxidase complex proteins. The activation of Gs protein coupled receptors (GPCRs) induces neuronal activation in the cAMP-dependent protein kinase A (PKA)-mediated signal cascade and regulates NADPH oxidase activity. However, it is unknown whether PKA regulates NADPH oxidase gene expression in neurons and microglia. In the present research, the NADPH oxidase gene expression was studied in rat cortical neurons and microglia in vitro. Purified microglial cells were identified with OX-42 antibody and they also expressed apolipoprotein E (ApoE). The time-dependent effect of cytokine interleukin-4 (IL-4) (20 ng/ml) in NADPH oxidase gene expression was studied in microglial cells. The levels of mRNA were determined by quantitative RT-PCR. The expression of NOX1, NOX2, and NCF2 was upregulated after IL-4 treatment for 4 h, but it was downregulated after 8-24 h. The expression of NCF1 was suppressed during any time of cytokine effect. IL-4 upregulated arginase1 (Arg1) and serine racemase1 (SRR1) gene expressions in microglia. Amyloid beta (Ab) suppressed NOX2, NCF1, and NCF2 gene expressions and upregulated glutamate cystine transporter (xCT), although IL-4 attenuated the effect of Ab (500 ?M) in the upregulation of xCT gene expression. The activation of PKA with agonist dibutyryl cAMP (dbcAMP) (100 ?M) induced the upregulation of Arg1 gene expression in microglia involving in the process of microglial activation. The transcription of NOX1, NOX2, and NCF1 was suppressed in microglial cells after dbcAMP treatment within 24 h. Neurons were identified with the microtubule-associated protein tau. The uniform distribution of tau along axons was established in normal neurons. Tau protein was redistributed after PKA agonist dbcAMP treatment for 24 h. L-glutamate (50 ?M) caused the apoptotic processes and the accumulation of tau in the soma of neurons and along axons. The activation of PKA for 24 h induced the transcriptional upregulation of NOX1 and NCF1 in cortical neurons. However, L-glutamate suppressed NOX1 gene expression in neurons. These data demonstrate that the effects of IL-4 and dbcAMP are similar in the regulation of SRR1, Arg1, and NADPH oxidase complex gene expressions in neurons and microglia. IL-4 prevents glutamate release from microglia suppressing xCT expression induced by Ab. These findings suggest that the activation of GPCR in PKA-mediated pathway leads to transcriptional regulation of NADPH oxidase complex. The modulation of GPCR activation may inhibit the oxidative stress in neurons. PMID:22565378

Savchenko, Valentina L

2012-05-08

103

Expression of Phanerochaete chrysosporium genes encoding lignin peroxidases, manganese peroxidases, and glyoxal oxidase in wood  

SciTech Connect

Lignin depolymerization is catalyzed by extracellular enzymes of white rot basidiomycetes such as Phanerochaete chrysosporium. Major components of this system include lignin peroxidases, manganese-dependent lignin peroxidases, and a peroxide-generating enzyme, glyoxal oxidase. Expression of Phanerochaete chrysosporium genes encoding ligninolytic enzymes was assessed in wood. Poly(A) RNA was extracted from colonized wood chips by magnetic capture, and specific transcripts were quantified by competitive reverse transcriptase PCR. mRNA levels varied substantially among lignin peroxidase genes, and transcript patterns were dramatically different from those in previous studies with defined media.

Janse, B.J.H. [Univ. of Stellenbosch (South Africa). Dept. of Microbiology; Gaskell, J.; Cullen, D. [Forest Products Lab., Madison, WI (United States). Inst. of Microbial and Biochemical Technology; Akhtar, M. [Forest Products Lab., Madison, WI (United States). Inst. of Microbial and Biochemical Technology]|[Univ of Wisconsin, Madison, WI (United States). Biotechnology Center

1998-09-01

104

The cyclope gene of Drosophila encodes a cytochrome c oxidase subunit VIc homolog.  

PubMed Central

Cytochrome c oxidase is the terminal enzyme of the mitochondrial electron transfer chain. In eukaryotes, the enzyme is composed of 3 mitochondrial DNA-encoded subunits and 7-10 (in mammals) nuclear DNA-encoded subunits. This enzyme has been extensively studied in mammals and yeast but, in Drosophila, very little is known and no mutant has been described so far. Here we report the genetic and molecular characterization of mutations in cyclope (cype) and the cloning of the gene encoding a cytochrome c oxidase subunit VIc homolog. cype is an essential gene whose mutations are lethal and show pleiotropic phenotypes. The 77-amino acid peptide encoded by cype is 46% identical and 59% similar to the human subunit (75 amino acids). The transcripts are expressed maternally and throughout development in localized regions. They are found predominantly in the central nervous system of the embryo; in the central region of imaginal discs; in the germarium, follicular, and nurse cells of the ovary; and in testis. A search in the Genome Annotation Database of Drosophila revealed the absence of subunit VIIb and the presence of 9 putative nuclear cytochrome c oxidase subunits with high identity scores when compared to the 10 human subunits.

Szuplewski, S; Terracol, R

2001-01-01

105

Identification, characterization, and localization of the human lysyl oxidase-related gene  

SciTech Connect

Lysyl oxidase (lox) initiates the formation of inter- and intra-strand covalent crosslinks of mature collagen and elastin in connective tissue. The lox gene has been cloned and mapped to human chromosome 5q23.3-31.2. The lysyl oxidase gene is approximately 15 kb in size and consists of seven exons. Lox mRNA is expressed at high levels in rat aorta and lung, and is undetectable in brain, kidney, liver, and heart. We have cloned and sequenced a lysyl oxidase-related cDNA, lox2, which exhibits amino acid sequence homology to the carboxyl end of lox. However, the function of lox2 is unknown. The tissue- and cell-specific expression patterns of lox2 have been examined by Northern blot analysis. Levels of lox2 mRNA in mouse and rat tissue is elevated in heart, lung, kidney and spleen; low in brain, and muscle, and is not detected in liver. In cultured cells, lox2 mRNA levels are high in human skin and corneal fibroblasts, human and rat lung fibroblasts, and rat lung epithelial-like cells. Low levels of lox2 mRNA are found in human pulmonary artery endothelial cells and neuroblastoma cells and are undetectable in human hepatoma cells. We have isolated multiple, unique, overlapping lox2 genomic clones from a human leukocyte genomic phage library. Using a genomic phage clone as a probe, we have mapped lox2 to human chromosome 15q23-24 using fluorescence in situ hybridization to human metaphase chromosomes. Characterization of the genomic phage clones indicates significant conservation of gene structure in the 3{prime} conserved region of lox2 relative to lox. This preservation of gene structure suggests a partial gene duplication between human chromosomes 15 and 5.

Carlisle, K.S.; Mellott, J.K. [Univ. of Florida College of Medicine, Gainesville, FL (United States); Yang, T.P. [Univ. of Florida College of Medicine, Gainesville, FL (United States)]|[Children`s Hospital of Philadelphia, PA (United States)] [and others

1994-09-01

106

GA-20 oxidase as a candidate for the semidwarf gene sdw1/denso in barley.  

PubMed

The barley sdw1/denso gene not only controls plant height but also yield and quality. The sdw1/denso gene was mapped to the long arm of chromosome 3H. Comparative genomic analysis revealed that the sdw1/denso gene was located in the syntenic region of the rice semidwarf gene sd1 on chromosome 1. The sd1 gene encodes a gibberellic acid (GA)-20 oxidase enzyme. The gene ortholog of rice sd1 was isolated from barley using polymerase chain reaction. The barley and rice genes showed a similar gene structure consisting of three exons and two introns. Both genes share 88.3% genomic sequence similarity and 89% amino acid sequence identity. A single nucleotide polymorphism was identified in intron 2 between barley varieties Baudin and AC Metcalfe with Baudin known to contain the denso semidwarf gene. The single nucleotide polymorphism (SNP) marker was mapped to chromosome 3H in a doubled haploid population of Baudin x AC Metcalfe with 178 DH lines. Quantitative trait locus analysis revealed that plant height cosegregated with the SNP. The sdw1/denso gene in barley is the most likely ortholog of the sd1 in rice. The result will facilitate understanding of the molecular mechanism controlling semidwarf phenotype and provide a diagnostic marker for selection of semidwarf gene in barley. PMID:19280236

Jia, Qiaojun; Zhang, Jingjuan; Westcott, Sharon; Zhang, Xiao-Qi; Bellgard, Mathew; Lance, Reg; Li, Chengdao

2009-03-12

107

Molecular Evolution at the Cytochrome Oxidase Subunit 2 Gene Among Divergent Populations of the Intertidal Copepod, Tigriopus californicus  

Microsoft Academic Search

The cytochrome c oxidase subunit 2 gene (COII) encodes a highly conserved protein that is directly responsible for the initial transfer of\\u000a electrons from cytochrome c to cytochrome c oxidase (COX) crucial to the production of ATP during cellular respiration. Despite its integral role in electron transport,\\u000a we have observed extensive intraspecific nucleotide and amino acid variation among 26 full-length

Paul D. Rawson; Ronald S. Burton

2006-01-01

108

Horizontal Gene Transfer Involved in the Convergent Evolution of the Plasmid-Encoded Enantioselective 6-Hydroxynicotine Oxidases  

Microsoft Academic Search

.   The D- and L-specific nicotine oxidases are flavoproteins involved in the oxidative degradation of nicotine by the Gram-positive\\u000a soil bacterium Arthrobacter nicotinovorans. Their structural genes are located on a 160-kbp plasmid together with those of other nicotine-degrading enzymes. They are\\u000a structurally unrelated at the DNA as well as at the protein level. Each of these oxidases possesses a high

S. Schenk; K. Decker

1999-01-01

109

Expression of the Talaromyces flavus glucose oxidase gene in cotton and tobacco reduces fungal infection, but is also phytotoxic  

Microsoft Academic Search

Glucose oxidase secreted by the fungus Talaromyces flavus generates, in the presence of glucose, hydrogen peroxide that is\\u000a toxic to phytopathogenic fungi responsible for economically important diseases in many crops. A glucose oxidase gene from\\u000a T. flavus, was modified with a carrot extensin signal peptide and fused to either a constitutive or root-specific plant promoter.\\u000a T1 tobacco plants expressing the enzyme

Fiona Murray; Danny Llewellyn; Helen McFadden; David Last; Elizabeth S. Dennis; W. James Peacock

1999-01-01

110

Enhancing Resistance to Sclerotinia minor in Peanut by Expressing a Barley Oxalate Oxidase Gene1  

PubMed Central

Sclerotinia minor Jagger is the causal agent of Sclerotinia blight, a highly destructive disease of peanut (Arachis hypogaea). Based on evidence that oxalic acid is involved in the pathogenicity of many Sclerotinia species, our objectives were to recover transgenic peanut plants expressing an oxalic acid-degrading oxalate oxidase and to evaluate them for increased resistance to S. minor. Transformed plants were regenerated from embryogenic cultures of three Virginia peanut cultivars (Wilson, Perry, and NC-7). A colorimetric enzyme assay was used to screen for oxalate oxidase activity in leaf tissue. Candidate plants with a range of expression levels were chosen for further analysis. Integration of the transgene was confirmed by Southern-blot analysis, and gene expression was demonstrated in transformants by northern-blot analysis. A sensitive fluorescent enzyme assay was used to quantify expression levels for comparison to the colorimetric protocol. A detached leaflet assay tested whether transgene expression could limit lesion size resulting from direct application of oxalic acid. Lesion size was significantly reduced in transgenic plants compared to nontransformed controls (65%–89% reduction at high oxalic acid concentrations). A second bioassay examined lesion size after inoculation of leaflets with S. minor mycelia. Lesion size was reduced by 75% to 97% in transformed plants, providing evidence that oxalate oxidase can confer enhanced resistance to Sclerotinia blight in peanut.

Livingstone, D. Malcolm; Hampton, Jaime L.; Phipps, Patrick M.; Grabau, Elizabeth A.

2005-01-01

111

A Phaseolus vulgaris NADPH oxidase gene is required for root infection by Rhizobia.  

PubMed

Plant NADPH oxidases [respiratory burst oxidase homologs (RBOHs)] have emerged as key players in the regulation of plant-pathogen interactions. Nonetheless, their role in mutualistic associations, such as the rhizobia-legume symbiosis, is poorly understood. In this work, nine members of the Phaseolus vulgaris Rboh gene family were identified. The transcript of one of these, PvRbohB, accumulated abundantly in shoots, roots and nodules. PvRbohB promoter activity was detected in meristematic regions of P. vulgaris roots, as well as during infection thread (IT) progression and nodule development. RNA interference (RNAi)-mediated PvRbohB down-regulation in transgenic roots reduced reactive oxygen species (ROS) production and lateral root density, and greatly impaired nodulation. Microscopy analysis revealed that progression of the ITs was impeded at the base of root hairs in PvRbohB-RNAi roots. Furthermore, the few nodules that formed in PvRbohB-down-regulated roots displayed abnormally wide ITs and reduced nitrogen fixation. These findings indicate that this common bean NADPH oxidase is crucial for successful rhizobial colonization and probably maintains proper IT growth and shape. PMID:22942250

Montiel, Jesús; Nava, Noreide; Cárdenas, Luis; Sánchez-López, Rosana; Arthikala, Manoj-Kumar; Santana, Olivia; Sánchez, Federico; Quinto, Carmen

2012-08-31

112

Investigation of cytocrom c oxidase gene subunits expression on the Multiple sclerosis  

PubMed Central

INTRODUCTION: Multiple sclerosis (MS) is an autoimmune inflamatory disease, which affects the (Central Nervous System) and leads to the destruction of myelin and atrophy of the axons. Genetic factors, in addition to environmental ones, seem to play a role in MS. Numerous studies have reported mitochondrial defects including a reduction in cytochrome c oxidase (COX) complex function related to the reduction of mitochondrial genes expression in the cortex tissue of patients with MS have been reported. MATERIALS AND METHODS: This study aimed to assess COX5B and COX2 genes expression in MS patients and compare it with normal subjects. We determine expression levels of genes COX5B and COX2, and also gene reference ß-actine using real–time polymerase chain reaction (RT-PCR) method. Data were obtained and obtained and standardized with the gene reference and were analyzed using independent sample t-test with SPSS and Excel programs. RESULT AND DISCUSSION: The resultshowed COX5B gene expression reduced significant in MS patients compared to normal subjects (P < ?0.05) whereas, there was no significant difference in the COX2 gene expression between normal subjects and patients. Thus, it can be claimed that down-regulation of mitochondrial electron transport chain genes supported the hypothesis that hypoxia-like tissue injury in MS may be due to mitochondrial genes, different expression impairment.

Safavizadeh, Naeimeh; Rahmani, Seyed Ali; Zaefizadeh, Mohamad

2013-01-01

113

Molecular cloning and expression characteristics of alternative oxidase gene of cotton ( Gossypium hirsutum )  

Microsoft Academic Search

A novel alternative oxidase (AOX) gene derived from cotton (Gossypium hirsutum), designated as GhAOX1, was cloned with RACE-PCR. The full-length cDNA of GhAOX1was 1,298 bp in size, containing a 996 bp open reading frame (ORF) which corresponds to a precursor protein of 332 amino acid\\u000a residues with a calculated molecular mass of 37.5 kDa. The predicted amino acid sequence exhibited 68.4%, 68.1%, 59.4%,

Fang Li; Yi Zhang; Meimei Wang; Ying Zhang; Xiaoliang Wu; Xingqi Guo

2008-01-01

114

Mitochondrial myopathy due to novel missense mutation in the cytochrome c oxidase 1 gene.  

PubMed

We report a novel heteroplasmic mutation p.Y440C in the mitochondrial DNA-encoded subunit I of the cytochrome c oxidase (COX) gene in a patient with late onset progressive painless weakness. Her muscle biopsy showed scattered COX-negative fibers and several small collections of inflammatory cells. The mutation was detected in the patient's muscle but not in her blood. The low mutant load in muscle could explain the patient's late onset of the myopathy and milder phenotype when compared to the previously published cases with MTCO1 mutations. PMID:22632780

Massie, Rami; Wang, Jing; Chen, Li-Chieh; Zhang, Victor W; Collins, Michael P; Wong, Lee-Jun C; Milone, Margherita

2012-05-24

115

Mutations in the Arabidopsis Gene IMMUTANS Cause a Variegated Phenotype by Inactivating a Chloroplast Terminal Oxidase Associated with Phytoene Desaturation  

Microsoft Academic Search

The immutans ( im ) mutant of Arabidopsis shows a variegated phenotype comprising albino and green somatic sectors. We have cloned the IM gene by transposon tagging and show that even stable null alleles give rise to a variegated phe- notype. The gene product has amino acid similarity to the mitochondrial alternative oxidase. We show that the IM pro- tein

Pierre Carol; David Stevenson; Cordelia Bisanz; Jürgen Breitenbach; Gerhard Sandmann; Regis Mache; George Coupland; Marcel Kuntz

1999-01-01

116

Structure and expression of the D-amino-acid oxidase gene from the yeast Rhodosporidium toruloides.  

PubMed

D-Amino-acid oxidase (DAO2; EC 1.4.3.3) catalyses the oxidative deamination of D-amino acids to alpha-keto acids and ammonia. The purified DAO protein from Rhodosporidium toruloides was used to determine its amino acid sequence. Three internal peptide sequences, YCQYLARELQ, IAGIDDQAAEPIR and RCTMDSSDP, were obtained and used to synthesize four fully degenerated oligonucleotides for cloning of the DAO gene. Both cDNA and genomic DNA encoding R. toruloides DAO were cloned and sequenced. Comparison of these two DNA sequences revealed that the DAO gene contains six exons and five introns. The gene encodes a polypeptide of 368 amino acids with a calculated molecular mass of 40,079 Da. Using an Escherichia coli protein expression system, the DAO protein of R. toruloides can easily be produced in an active form and purified in a large quantity. PMID:9477555

Liao, G J; Lee, Y J; Lee, Y H; Chen, L L; Chu, W S

1998-02-01

117

Functionally undefined gene, yggE , alleviates oxidative stress generated by monoamine oxidase in recombinant Escherichia coli  

Microsoft Academic Search

Real-time PCR analysis showed that yggE gene was about two and three times up-regulated in Escherichia coli cells exposed to UVA irradiation and thermal elevation, respectively, suggesting that this gene is responsive to physiological\\u000a stress. The yggE gene was introduced into E. coli BL21 cells, together with a monoamine oxidase (MAO) gene as a model source for oxidative stress generation. The distribution

Yoshihiro Ojima; Daisuke Kawase; Motomu Nishioka; Masahito Taya

2009-01-01

118

Cloning, sequencing, and characterization of five genes coding for Acyl-CoA oxidase isozymes in the yeast Yarrowia lipolytica  

Microsoft Academic Search

The Acyl-CoA oxidase (AOX) isozymes catalyze the first steps of peroxisomal ?-oxidation, which is important for the degradation\\u000a of fatty acids. Using conserved blocks in previously identified yeastPOX genes encoding AOXs, the authors have shown that fivePOX genes are present in the yeastYarrowia lipolytica. These genes show approx 63% identity among themselves, and 42% identity with thePOX genes from other

Huijie Wang; Marie-Thérése Le Dall; Yves Waché; Céline Laroche; Jean-Marc Belin; Jean-Marc Nicaud

1999-01-01

119

Identification of a gene causing human cytochrome c oxidase deficiency by integrative genomics  

PubMed Central

Identifying the genes responsible for human diseases requires combining information about gene position with clues about biological function. The recent availability of whole-genome data sets of RNA and protein expression provides powerful new sources of functional insight. Here we illustrate how such data sets can expedite disease-gene discovery, by using them to identify the gene causing Leigh syndrome, French-Canadian type (LSFC, Online Mendelian Inheritance in Man no. 220111), a human cytochrome c oxidase deficiency that maps to chromosome 2p16-21. Using four public RNA expression data sets, we assigned to all human genes a “score” reflecting their similarity in RNA-expression profiles to known mitochondrial genes. Using a large survey of organellar proteomics, we similarly classified human genes according to the likelihood of their protein product being associated with the mitochondrion. By intersecting this information with the relevant genomic region, we identified a single clear candidate gene, LRPPRC. Resequencing identified two mutations on two independent haplotypes, providing definitive genetic proof that LRPPRC indeed causes LSFC. LRPPRC encodes an mRNA-binding protein likely involved with mtDNA transcript processing, suggesting an additional mechanism of mitochondrial pathophysiology. Similar strategies to integrate diverse genomic information can be applied likewise to other disease pathways and will become increasingly powerful with the growing wealth of diverse, functional genomics data.

Mootha, Vamsi K.; Lepage, Pierre; Miller, Kathleen; Bunkenborg, Jakob; Reich, Michael; Hjerrild, Majbrit; Delmonte, Terrye; Villeneuve, Amelie; Sladek, Robert; Xu, Fenghao; Mitchell, Grant A.; Morin, Charles; Mann, Matthias; Hudson, Thomas J.; Robinson, Brian; Rioux, John D.; Lander, Eric S.

2003-01-01

120

DNA sequence analysis of the 24.5 Kilobase pair cytochrome oxidase subunit I mitochondrial gene from Podospora anserina : a gene with sixteen introns  

Microsoft Academic Search

The DNA sequence of a 26.7 Kilobase pair (103 base pairs = 1 Kb) region of the mitochondrial genomes of races s and A from Podospora anserina was determined. Within this region, the 24.5 Kb cytochrome oxidase subunit I gene was located and its exon sequences determined by computer analysis comparisons with other fungal genes. The Podospora COI gene was

Donald J. Cummings; François Michel; Kenneth L. MeNally

1989-01-01

121

Identification of forensically important Sarcophagidae (Diptera) based on partial mitochondrial cytochrome oxidase I and II genes.  

PubMed

Entomological evidence is of great importance in forensic cases for postmortem interval calculation. The use of Sarcophagidae (Diptera) for postmortem interval estimation is limited because morphological determination is often hampered because of similar characteristics in the larval, pupal, and even adult stage. To make the species identification more accurate and reliable, DNA-based identification is considered. In this study, we assessed the use of partial mitochondrial cytochrome oxidase I and II genes for discrimination of forensically important Sarcophagidae from Egypt and China [Sarcophaga argyrostoma (Robineau-Desvoidy), Sarcophaga dux (Thomson), Sarcophaga albiceps (Meigen), and Wohlfahrtia nuba (Wiedemann)]. This region was amplified using polymerase chain reaction followed by direct sequencing of the amplification products and using restriction enzymes HinfI and MfeI. Nucleotide sequence divergences were calculated using the Kimura 2-parameter distance model, and a neighbor-joining phylogenetic tree was generated. All examined specimens were assigned to the correct species. Combinations of the restriction enzymes HinfI and MfeI provide different restriction fragment length polymorphism profiles even among 3 sympatric species that belong to the Sarcophaga genus. Therefore, this study demonstrates that the studied partial mitochondrial cytochrome oxidase I and II genes were found to be instrumental for the molecular identification of these forensically important flesh fly species. PMID:23629402

Aly, Sanaa Mohamed; Wen, Jifang; Wang, Xiang

2013-06-01

122

Three-dimensional organization of three-domain copper oxidases: A review  

NASA Astrophysics Data System (ADS)

“Blue” copper-containing proteins are multidomain proteins that utilize a unique redox property of copper ions. Among other blue multicopper oxidases, three-domain oxidases belong to the group of proteins that exhibit a wide variety of compositions in amino acid sequences, functions, and occurrences in organisms. This paper presents a review of the data obtained from X-ray diffraction investigations of the three-dimensional structures of three-domain multicopper oxidases, such as the ascorbate oxidase catalyzing oxidation of ascorbate to dehydroascorbate and its three derivatives; the multicopper oxidase CueO (the laccase homologue); the laccases isolated from the basidiomycetes Coprinus cinereus, Trametes versicolor, Coriolus zonatus, Cerrena maxima, and Rigidoporus lignosus and the ascomycete Melanocarpus albomyces; and the bacterial laccases CotA from the endospore coats of Bacillus subtilis. A comparison of the molecular structures of the laccases of different origins demonstrates that, structurally, these objects are highly conservative. This obviously indicates that the catalytic activity of the enzymes under consideration is characterized by similar mechanisms.

Zhukhlistova, N. E.; Zhukova, Yu. N.; Lyashenko, A. V.; Za?tsev, V. N.; Mikha?lov, A. M.

2008-01-01

123

Three-dimensional organization of three-domain copper oxidases: A review  

SciTech Connect

'Blue' copper-containing proteins are multidomain proteins that utilize a unique redox property of copper ions. Among other blue multicopper oxidases, three-domain oxidases belong to the group of proteins that exhibit a wide variety of compositions in amino acid sequences, functions, and occurrences in organisms. This paper presents a review of the data obtained from X-ray diffraction investigations of the three-dimensional structures of three-domain multicopper oxidases, such as the ascorbate oxidase catalyzing oxidation of ascorbate to dehydroascorbate and its three derivatives; the multicopper oxidase CueO (the laccase homologue); the laccases isolated from the basidiomycetes Coprinus cinereus, Trametes versicolor, Coriolus zonatus, Cerrena maxima, and Rigidoporus lignosus and the ascomycete Melanocarpus albomyces; and the bacterial laccases CotA from the endospore coats of Bacillus subtilis. A comparison of the molecular structures of the laccases of different origins demonstrates that, structurally, these objects are highly conservative. This obviously indicates that the catalytic activity of the enzymes under consideration is characterized by similar mechanisms.

Zhukhlistova, N. E., E-mail: amm@ns.crys.ras.ru; Zhukova, Yu. N.; Lyashenko, A. V. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Zaitsev, V. N. [University of St. Andrews, Centre for Biomolecular Sciences (United Kingdom); Mikhailov, A. M. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)

2008-01-15

124

Identification of a nitroalkane oxidase gene: naoA related to the growth of Streptomyces ansochromogenes.  

PubMed

naoA, encoding a nitroalkane oxidase that can catalyze toxic nitroalkanes to their corresponding aldehydes or ketones and hydrogen peroxide, was cloned from Streptomyces ansochromogenes, but its function related to the growth of Streptomyces is unknown. naoA was disrupted by the insertion of a kanamycin-resistance gene; the resulting strain can grow earlier than a wild-type strain under the same conditions. It was shown that naoA disruption accelerated growth of the naoA-disruption mutant, which could restore its phenotype and morphology as a wild-type strain by complementation of a single copy number of naoA inserted into the chromosome. The introduction of an extra copy of naoA into the wild-type strain resulted in delayed growth. The result suggested that naoA is an important gene related to the growth of S. ansochromogenes. PMID:18810541

Li, Yanhua; Zhang, Jihui; Tan, Huarong

2008-09-23

125

Homozygous variegate porphyria: a compound heterozygote with novel mutations in the protoporphyrinogen oxidase gene.  

PubMed

Homozygous variegate porphyria results from mutations in both alleles of the protoporphyrinogen oxidase (PPOX) gene. Our patient, a 36-year-old woman, has severe cutaneous manifestations. Her clinical and biochemical features are similar to the few other reported cases, including onset before 18 months of age, photosensitivity, absence of acute porphyric attacks, and elevated erythrocyte protoporphyrin. Mutation analysis of the PPOX gene revealed an in-frame 12 bp insert (c. 657-658 ins AAGGCCAGCGCC) encoding lysine-alanine-serine-alanine (KASA), and a G to A transition at the splice donor site of exon 11 (IVS 11-1 G-->A). Neither of these mutations has been reported previously. Our patient's mother has the splice site mutation and has had acute porphyric episodes. A maternal first cousin has the same mutation but no clinical manifestations. The medical and family history of our patient's father is uncertain. PMID:11298551

Palmer, R A; Elder, G H; Barrett, D F; Keohane, S G

2001-04-01

126

Molecular basis of variegate porphyria: a missense mutation in the protoporphyrinogen oxidase gene.  

PubMed

Variegate porphyria (VP) is an autosomal dominant disorder characterised by a partial defect in the activity of protoporphyrinogen oxidase (PPO), and has recently been genetically linked to the PPO gene on chromosome 1q22-23 (Z=6.62). In this study, we identified a mutation in the PPO gene in a patient with VP and two unaffected family members. The mutation consisted of a previously unreported T to C transition in exon 13 of the PPO gene, resulting in the substitution of a polar serine by a non-polar proline (S450P). This serine residue is evolutionarily highly conserved in man, mouse, and Bacillus subtilis, attesting to the importance of this residue. Interestingly, the gene for Gardner's syndrome (FAP) also segregates in this family, independently of the VP mutation. Gardner's syndrome or familial adenomatous polyposis (FAP) is also an autosomal dominantly inherited genodermatosis, and typically presents with colorectal cancer in early adult life secondary to extensive adenomatous polyps of the colon. The specific gene on chromosome 5 that is the site of the mutation in this disorder is known as APC (adenomatous polyposis coli), and the gene has been genetically linked to the region of 5q22. PMID:9541112

Frank, J; Lam, H; Zaider, E; Poh-Fitzpatrick, M; Christiano, A M

1998-03-01

127

Homozygous variegate porphyria: identification of mutations on both alleles of the protoporphyrinogen oxidase gene in a severely affected proband.  

PubMed

Homozygous variegate porphyria is a severe skin and neurologic disease manifesting in early infancy, and characterized by markedly reduced levels of the penultimate enzyme in the heme biosynthetic pathway, protoporphyrinogen oxidase. We investigated the molecular basis of variegate porphyria, usually an autosomal dominantly inherited trait, in a severely affected female proband and her parents. The mutation detection strategy included heteroduplex analysis, automated sequencing, and allele specific oligonucleotide hybridization. We identified two underlying missense mutations in the protoporphyrinogen oxidase gene, consisting of a G-to-A transition in exon 6 (G169E), and a G-to-A transition in exon 10 (G358R). Our study establishes the molecular basis of "homozygous" variegate porphyria for the first time, in demonstrating that this patient is a compound heterozygote for two different missense mutations in the protoporphyrinogen oxidase gene. PMID:9540991

Frank, J; McGrath, J; Lam, H; Graham, R M; Hawk, J L; Christiano, A M

1998-04-01

128

Exclusion of urate oxidase as a candidate gene for hyperuricosuria in the Dalmatian dog using an interbreed backcross.  

PubMed

Hyperuricosuria, an autosomal recessive disorder, is characterized by high levels of uric acid in the urine of Dalmatian dogs. Whereas high levels of uric acid are known to be caused by the silencing of the urate oxidase (uox) gene in humans and higher primates, the molecular basis for the Dalmatian defect is unknown. Transplantation studies show that the organ responsible for the Dalmatian phenotype is the liver, which is where urate oxidase is exclusively expressed and uric acid is converted into allantoin. We cloned and sequenced the canine uox cDNA and compared the sequence between a Dalmatian and non-Dalmatian dog. No change in cDNA sequence was identified. A Dalmatian x pointer backcross family was used to track the segregation of microsatellite markers surrounding the urate oxidase locus. The uox gene was excluded for Dalmatian hyperuricosuria based on the cDNA sequence identity and negative LOD scores. PMID:15958795

Safra, N; Ling, G V; Schaible, R H; Bannasch, D L

2005-06-15

129

D-amino-acid oxidase gene from Rhodotorula gracilis (Rhodosporidium toruloides) ATCC 26217.  

PubMed

The complete nucleotide sequence of the DAO1 gene encoding D-amino-acid oxidase (DAAO) in the yeast Rhodotorula gracilis (Rhodosporidium toruloides) ATCC 26217 has been determined. The primary structure of DAAO was deduced from the nucleotide sequence of a cDNA clone that covered the entire amino acid coding sequence. Comparison of cDNA and genomic sequences of DAO1 revealed the presence of five introns. Because this is the first gene of strain ATCC 26217 that has been cloned so far, the nucleotide sequences of these introns were compared to those from other fungi. Upstream of the structural gene there was a stretch of C + T-rich DNA similar to that found in the promoter region of a number of yeast genes. The cDNA gene, which encoded a protein of 368 amino acids (molecular mass 40 kDa), was overexpressed in Escherichia coli under the control of the strong lipoprotein promoter. Interestingly, a significant fraction (13-62%) of the total DAAO activity was recovered in its apoenzyme form, the percentage depending on the culture conditions. This fact allowed a rapid purification of the recombinant DAAO by affinity chromatography. The high level of expression achieved in E. coli and the possibility of modifying its catalytic properties by protein engineering provide a new model for the study of this enzyme. PMID:9579082

Alonso, J; Barredo, J L; Díez, B; Mellado, E; Salto, F; García, J L; Cortés, E

1998-04-01

130

The terminal quinol oxidase of the hyperthermophilic archaeon Acidianus ambivalens exhibits a novel subunit structure and gene organization.  

PubMed

A terminal quinol oxidase has been isolated from the plasma membrane of the crenarchaeon Acidianus ambivalens (DSM 3772) (formerly Desulfurolobus ambivalens), cloned, and sequenced. The detergent-solubilized complex oxidizes caldariella quinol at high rates and is completely inhibited by cyanide and by quinolone analogs, potent inhibitors of quinol oxidases. It is composed of at least five different subunits of 64.9, 38, 20.4, 18.8, and 7.2 kDa; their genes are located in two different operons. doxB, the gene for subunit I, is located together with doxC and two additional small open reading frames (doxE and doxF) in an operon with a complex transcription pattern. Two other genes of the oxidase complex (doxD and doxA) are located in a different operon and are cotranscribed into a common 1.2-kb mRNA. Both operons exist in duplicate on the genome of A. ambivalens. Only subunit I exhibits clear homology to other members of the superfamily of respiratory heme-copper oxidases; however, it reveals 14 transmembrane helices. In contrast, the composition of the accessory proteins is highly unusual; none is homologous to any known accessory protein of cytochrome oxidases, nor do homologs exist in the databases. DoxA is classified as a subunit II equivalent only by analogy of molecular size and hydrophobicity pattern to corresponding polypeptides of other oxidases. Multiple alignments and phylogenetic analysis of the heme-bearing subunit I (DoxB) locate this oxidase at the bottom of the phylogenetic tree, in the branch of heme-copper oxidases recently suggested to be incapable of superstoichiometric proton pumping. This finding is corroborated by lack of the essential amino acid residues delineating the putative H+-pumping channel. It is therefore concluded that A. ambivalens copes with its strongly acidic environment simply by an extreme turnover of its terminal oxidase, generating a proton gradient only by chemical charge separation. PMID:9023221

Purschke, W G; Schmidt, C L; Petersen, A; Schäfer, G

1997-02-01

131

Cytochrome Oxidase Activity and Mitochondrial Gene Expression in Skeletal Muscle of Patients with Chronic Obstructive Pulmonary Disease  

Microsoft Academic Search

Several recent studies have suggested that skeletal muscle bioenergetics are abnormal in patients with chronic obstructive pulmonary disease (COPD). This study investigates the activity of cyto- chrome oxidase (COX), the terminal enzyme in the mitochondrial electron transport chain, and the expression of two mitochondrial DNA genes related to COX (mRNA of subunit I of COX (COX-I) and the RNA component

JAUME SAULEDA; FRANCISCO GARCÍA-PALMER; RUDOLF J. WIESNER; SALVADOR TARRAGA; INGA HARTING; PURIFICACIÓN TOMÁS; CRISTINA GÓMEZ; CARLES SAUS; ANDREU PALOU; ALVAR G. N. AGUSTÍ

1998-01-01

132

Molecular Evolution of Tephritid Fruit Flies in the Genus Bactrocera Based on the Cytochrome Oxidase I Gene  

Microsoft Academic Search

Fruit flies of the genus Bactrocera (Diptera: Tephritidae) are one of the major economically important insects in Asia and Australia. Little attention has been given to analyses of molecular phylogenetic relationships among Bactrocera subgenera. By using mitochondrial cytochrome oxidase I gene (COI) sequences, the phylogenetic relationships among four subgenera, Asiadacus, Bactrocera, Hemigymnodacus, and Zeugodacus, were investigated. Nucleotide diversity within subgenera

Wanwisa Jamnongluk; Visut Baimai; Pattamaporn Kittayapong

2003-01-01

133

Description of the Cytochrome c Oxidase Subunit II Gene in Some Genera of New World Monkeys (Primates, Platyrrhini)  

Microsoft Academic Search

Nucleotide sequence variation at the mitochondrial cytochrome c oxidase subunit II gene (COII) was analyzed in 27 New World monkey specimens, nine newly reported herein. The study involved comparisons among platyrrhines and also between platyrrhines and catarrhines. The analysis of the frequencies of transitions and transversions at each codon position showed transitional saturation at third codon position. Neighbor-Joining trees obtained

Marina S. Ascunce; Esteban Hasson; Marta D. Mudry

2002-01-01

134

Abnormal behavior associated with a point mutation in the structural gene for monoamine oxidase A  

SciTech Connect

Genetic and metabolic studies have been done on a large kindred in which several males are affected by a syndrome of borderline mental retardation and abnormal behavior. The types of behavior that occurred include impulsive aggression, arson, attempted rape, and exhibitionism. Analysis of 24-hour urine samples indicated markedly disturbed monoamine metabolism. This syndrome was associated with a complete and selective deficiency of enzymatic activity of monoamine oxidase A (MAOA). In each of five affected males, a point mutation was identified in the eighth exon of the MAOA structural gene, which changes a glutamine to a termination codon. Thus, isolated complete MAOA deficiency in this family is associated with a recognizable behavioral phenotype that includes disturbed regulation of impulsive aggression.

Brunner, H.G. (Univ. Hospital, Nijmegan (Netherlands)); Nelen, M.; Ropers, H.H.; van Oost, B.A. (Univ. Hospital Nijmegen (Netherlands))

1993-10-22

135

DNA barcoding of Oryx leucoryx using the mitochondrial cytochrome C oxidase gene.  

PubMed

The massive destruction and deterioration of the habitat of Oryx leucoryx and illegal hunting have decimated Oryx populations significantly, and now these animals are almost extinct in the wild. Molecular analyses can significantly contribute to captive breeding and reintroduction strategies for the conservation of this endangered animal. A representative 32 identical sequences used for species identification through BOLD and GenBank/NCBI showed maximum homology 96.06% with O. dammah, which is a species of Oryx from Northern Africa, the next closest species 94.33% was O. gazella, the African antelope. DNA barcode sequences of the mitochondrial cytochrome C oxidase (COI) gene were determined for O. leucoryx; identification through BOLD could only recognize the genus correctly, whereas the species could not be identified. This was due to a lack of sequence data for O. leucoryx on BOLD. Similarly, BLAST analysis of the NCBI data base also revealed no COI sequence data for the genus Oryx. PMID:22535389

Elmeer, K; Almalki, A; Mohran, K A; Al-Qahtani, K N; Almarri, M

2012-03-08

136

Abnormal behavior associated with a point mutation in the structural gene for monoamine oxidase A.  

PubMed

Genetic and metabolic studies have been done on a large kindred in which several males are affected by a syndrome of borderline mental retardation and abnormal behavior. The types of behavior that occurred include impulsive aggression, arson, attempted rape, and exhibitionism. Analysis of 24-hour urine samples indicated markedly disturbed monoamine metabolism. This syndrome was associated with a complete and selective deficiency of enzymatic activity of monoamine oxidase A (MAOA). In each of five affected males, a point mutation was identified in the eighth exon of the MAOA structural gene, which changes a glutamine to a termination codon. Thus, isolated complete MAOA deficiency in this family is associated with a recognizable behavioral phenotype that includes disturbed regulation of impulsive aggression. PMID:8211186

Brunner, H G; Nelen, M; Breakefield, X O; Ropers, H H; van Oost, B A

1993-10-22

137

Cloning and Characterization of Three Fatty Alcohol Oxidase Genes from Candida tropicalis Strain ATCC 20336  

PubMed Central

Candida tropicalis (ATCC 20336) converts fatty acids to long-chain dicarboxylic acids via a pathway that includes among other reactions the oxidation of ?-hydroxy fatty acids to ?-aldehydes by a fatty alcohol oxidase (FAO). Three FAO genes (one gene designated FAO1 and two putative allelic genes designated FAO2a and FAO2b), have been cloned and sequenced from this strain. A comparison of the DNA sequence homology and derived amino acid sequence homology between these three genes and previously published Candida FAO genes indicates that FAO1 and FAO2 are distinct genes. Both genes were individually cloned and expressed in Escherichia coli. The substrate specificity and Km values for the recombinant FAO1 and FAO2 were significantly different. Particularly striking is the fact that FAO1 oxidizes ?-hydroxy fatty acids but not 2-alkanols, whereas FAO2 oxidizes 2-alkanols but not ?-hydroxy fatty acids. Analysis of extracts of strain H5343 during growth on fatty acids indicated that only FAO1 was highly induced under these conditions. FAO2 contains one CTG codon, which codes for serine (amino acid 177) in C. tropicalis but codes for leucine in E. coli. An FAO2a construct, with a TCG codon (codes for serine in E. coli) substituted for the CTG codon, was prepared and expressed in E. coli. Neither the substrate specificity nor the Km values for the FAO2a variant with a serine at position 177 were radically different from those of the variant with a leucine at that position.

Eirich, L. Dudley; Craft, David L.; Steinberg, Lisa; Asif, Afreen; Eschenfeldt, William H.; Stols, Lucy; Donnelly, Mark I.; Wilson, C. Ron

2004-01-01

138

Discovery of a Gene Involved in a Third Bacterial Protoporphyrinogen Oxidase Activity through Comparative Genomic Analysis and Functional Complementation ? †  

PubMed Central

Tetrapyrroles are ubiquitous molecules in nearly all living organisms. Heme, an iron-containing tetrapyrrole, is widely distributed in nature, including most characterized aerobic and facultative bacteria. A large majority of bacteria that contain heme possess the ability to synthesize it. Despite this capability and the fact that the biosynthetic pathway has been well studied, enzymes catalyzing at least three steps have remained “missing” in many bacteria. In the current work, we have employed comparative genomics via the SEED genomic platform, coupled with experimental verification utilizing Acinetobacter baylyi ADP1, to identify one of the missing enzymes, a new protoporphyrinogen oxidase, the penultimate enzyme in heme biosynthesis. COG1981 was identified by genomic analysis as a candidate protein family for the missing enzyme in bacteria that lacked HemG or HemY, two known protoporphyrinogen oxidases. The predicted amino acid sequence of COG1981 is unlike those of the known enzymes HemG and HemY, but in some genomes, the gene encoding it is found neighboring other heme biosynthetic genes. When the COG1981 gene was deleted from the genome of A. baylyi, a bacterium that lacks both hemG and hemY, the organism became auxotrophic for heme. Cultures accumulated porphyrin intermediates, and crude cell extracts lacked protoporphyrinogen oxidase activity. The heme auxotrophy was rescued by the presence of a plasmid-borne protoporphyrinogen oxidase gene from a number of different organisms, such as hemG from Escherichia coli, hemY from Myxococcus xanthus, or the human gene for protoporphyrinogen oxidase.

Boynton, Tye O.; Gerdes, Svetlana; Craven, Sarah H.; Neidle, Ellen L.; Phillips, John D.; Dailey, Harry A.

2011-01-01

139

Nine novel mutations in the protoporphyrinogen oxidase gene in Swedish families with variegate porphyria.  

PubMed

Variegate porphyria (VP) is an autosomal-dominant disorder that is caused by inheritance of a partial deficiency of the enzyme protoporphyrinogen oxidase (EC 1.3.3.4). It is characterized by cutaneous photosensitivity and/or various neurological manifestations. Protoporphyrinogen oxidase catalyses the penultimate step of haem biosynthesis, and mutations in the PPOX gene have been coupled to VP. In the present study, sequencing analysis revealed 10 different mutations in the PPOX gene in 14 out of 17 apparently unrelated Swedish VP families. Six of the identified mutations, 3G > A (exon 2), 454C > T (exon 5), 472G > C (exon 6), 614C > T (exon 6), 988G > C (exon 10) and IVS12 + 2T > G (intron 12), are single nucleotide substitutions, while 604delC (exon 6), 916-17delCT (exon 9) and 1330-31delCT (exon 13) are small deletions, and IVS12 + 2-3insT (intron 12) is a small insertion. Only one of these 10 mutations has been reported previously. Three of the mutations were each identified in two or more families, while the remaining mutations were specific for an individual family. In addition to the 10 mutations, one previously unreported single nucleotide polymorphism was identified. Mutation analysis of family members revealed two adults and four children who were silent carriers of the VP trait. Genetic analysis can now be added to the conventional biochemical analyses and used in investigation of putative carriers of a VP trait in these families. PMID:12859407

Wiman, A; Harper, P; Floderus, Y

2003-08-01

140

Genes for a microaerobically induced oxidase complex in Bradyrhizobium japonicum are essential for a nitrogen-fixing endosymbiosis.  

PubMed Central

We report the discovery of a Bradyrhizobium japonicum gene cluster (fixNOQP) in which mutations resulted in defective soybean root-nodule bacteroid development and symbiotic nitrogen fixation. The predicted, DNA-derived protein sequences suggested that FixN is a heme b and copper-binding oxidase subunit, FixO a monoheme cytochrome c, FixQ a polypeptide of 54 amino acids, and FixP a diheme cytochrome c and that they are all membrane-bound. The isolation and analysis of membrane proteins from B. japonicum wild-type and mutant cells revealed two c-type cytochromes of 28 and 32 kDa as the likely products of the fixO and fixP genes and showed that both were synthesized only under oxygen-limited growth conditions. Furthermore, fixN insertion and fixNO deletion mutants grown microaerobically or anaerobically (with nitrate) exhibited a strong decrease in whole-cell oxidase activity as compared with the wild type. The data suggest that the fixNOQP gene products are induced at low oxygen concentrations and constitute a member of the bacterial heme/copper cytochrome oxidase superfamily. The described features are compatible with the postulate that this oxidase complex is specifically required to support bacterial respiration in endosymbiosis. Images Fig. 4 Fig. 5

Preisig, O; Anthamatten, D; Hennecke, H

1993-01-01

141

Single nucleotide polymorphisms of the protoporphyrinogen oxidase gene: inter-population heterogeneity of allelic variation.  

PubMed

Five single nucleotide polymorphisms (SNPs) in the protoporphyrinogen oxidase gene (PPOX) were used for inter-population comparisons of six South African populations and two non-South African Caucasian populations. Novel polymorphisms identified in the promoter region and exon 11 of the PPOX gene, as well as three known variants in exon 1 and intron 2, were analysed using single-strand conformation polymorphism (SSCP) and restriction enzyme analyses. Significant population differences were found for four of the five polymorphisms analysed. A G-to-A transition was found at nucleotide position -1081 and is the first polymorphism to be identified in the 5' promoter region of the gene. A novel A-to-C substitution at nucleotide position 3880 in exon 11 was not detected in subjects of European descent. This study represents the first inter-population comparison of allelic variation at the PPOX locus. The significant differences observed between populations demonstrate the importance of population considerations when marker association studies are performed at this locus. PMID:11513556

Warnich, L; Waso, H F; Groenewald, I M; Bester, A E; de Villiers, J N; Kotze, M J; Lynch, A G; Louw, J H

2001-08-01

142

Sequence of the 18S-5S ribosomal gene region and the cytochrome oxidase II gene from mtDNA of Zea diploperennis  

Microsoft Academic Search

The coding and flanking sequences of the 18S-5S ribosomal RNA genes and the cytochrome oxidase subunit II gene of Zea diploperennis mitochondrial DNA have been determined and compared to the corresponding sequences of normal maize (Zea mays L.) Both length and substitution mutations are found in the coding region of the 18S rRNA gene, whereas only one substitution mutation is

B. Gwynn; R. E. Dewey; R. R. Sederoff; D. H. Timothy; C. S. Levjngs

1987-01-01

143

Molecular characterization of the Drosophila melanogaster urate oxidase gene, an ecdysone-repressible gene expressed only in the malpighian tubules.  

PubMed Central

The urate oxidase (UO) gene of Drosophila melanogaster is expressed during the third-instar larval and adult stages, exclusively within a subset of cells of the Malpighian tubules. The UO gene contains a 69-base-pair intron and encodes mature mRNAs of 1,224, 1,227, and 1,244 nucleotides, depending on the site of 3' endonucleolytic cleavage prior to polyadenylation. A direct repeat, 5'-AAGTGAGAGTGAT-3', is the proposed cis-regulatory element involved in 20-hydroxyecdysone repression of the UO gene. The deduced amino acid sequences of UO of D. melanogaster, rat, mouse, and pig and uricase II of soybean show 32 to 38% identity, with 22% of amino acid residues identical in all species. With use of P-element-mediated germ line transformation, 826 base pairs 5' and approximately 1,200 base pairs 3' of the D. melanogaster UO transcribed region contain all of the cis elements allowing for appropriate temporal regulation and Malpighian tubule-specific expression of the UO gene. Images

Wallrath, L L; Burnett, J B; Friedman, T B

1990-01-01

144

Identification of an Alternative Oxidase Induction Motif in the Promoter Region of the aod-1 Gene in Neurospora crassa  

PubMed Central

The nuclear aod-1 gene of Neurospora crassa encodes the alternative oxidase and is induced when the standard cytochrome-mediated respiratory chain of mitochondria is inhibited. To study elements of the pathway responsible for alternative oxidase induction, we generated a series of mutations in the region upstream from the aod-1 structural gene and transformed the constructs into an aod-1 mutant strain. Transformed conidia were plated on media containing antimycin A, which inhibits the cytochrome-mediated electron transport chain so that only cells expressing alternative oxidase will grow. Using this functional in vivo assay, we identified an alternative oxidase induction motif (AIM) that is required for efficient expression of aod-1. The AIM sequence consists of two CGG repeats separated by 7 bp and is similar to sequences known to be bound by members of the Zn(II)2Cys6 binuclear cluster family of transcription factors. The AIM motif appears to be conserved in other species found in the order Sordariales.

Chae, Michael S.; Lin, Colin C.; Kessler, Katherine E.; Nargang, Cheryl E.; Tanton, Lesley L.; Hahn, Leanne B.; Nargang, Frank E.

2007-01-01

145

Recurrent missense mutation in the protoporphyrinogen oxidase gene underlies variegate porphyria.  

PubMed

The porphyrias represent a heterogeneous group of disorders of porphyrin or porphyrin-precursor metabolism, resulting from the inherited or acquired dysregulation of one of the eight enzymes in the porphyrin-heme biosynthetic pathway. Variegate porphyria, one of the acute hepatic porphyrias, is characterized by a partial reduction in the activity of the penultimate enzyme in the heme biosynthetic pathway, protoporphyrinogen oxidase (PPO). Recently, VP has been linked to the PPO gene on chromosome 1q22-23, and several disease-causing mutations have been described. In this study, we identified the underlying genetic lesion in two unrelated patients with VP and investigated all available family members by polymerase chain reaction, heteroduplex analysis, automated sequencing, and restriction enzyme digestion. Mutation analyses in both families revealed a G-to-A transition in exon 6 of the PPO gene resulting in the substitution of arginine by histidine at position 168 of the protein (R168H). This arginine residue is evolutionarily conserved in human, mouse, and Bacillus subtilis, indicating the importance of this residue in PPO function. Our study establishes a recurrent missense mutation as the underlying genetic defect in two unrelated patients with VP and explains the occurrence of the phenotype in their families. PMID:9738863

Frank, J; Jugert, F K; Breitkopf, C; Goerz, G; Merk, H F; Christiano, A M

1998-08-27

146

Mutations in the translation initiation codon of the protoporphyrinogen oxidase gene underlie variegate porphyria.  

PubMed

Variegate porphyria (VP), one of the acute hepatic porphyrias, is characterized by a reduced catalytic activity of protoporphyrinogen oxidase (PPO), the penultimate enzyme in the porphyrin-haem biosynthetic pathway. VP has been linked to the PPO gene on chromosome 1q22-23, and several mutations underlying this disorder have been described recently. In this study, we identified two different missense mutations in the translation initiation codon of the PPO gene in two unrelated patients with VP. Mutation analysis was carried out using PCR, heteroduplex analysis, automated sequencing, and restriction enzyme digestion. In the first patient, the results revealed an A-to-T transversion (ATG --> TTG), resulting in the substitution of methionine by leucine (M1L). The mutation detected in the second patient was a T-to-C transition (ATG --> ACG), leading to the conversion of methionine to threonine (M1T). These mutations abolish the initiation of translation at the normal site, and consequently, translation of an abnormal messenger RNA (mRNA) would result in the synthesis of a truncated PPO protein lacking the amino terminus. PMID:10457135

Frank, J; McGrath, J A; Poh-Fitzpatrick, M B; Hawk, J L; Christiano, A M

1999-07-01

147

Functional studies of mutations in the human protoporphyrinogen oxidase gene in variegate porphyria.  

PubMed

The autosomal dominant disorder, variegate porphyria (VP), results from mutations in the protoporphyrinogen oxidase (PPOX) gene. We have investigated the effects of 22 disease-associated missense mutations in this gene on enzyme activity. Mutants were generated in the expression plasmid pHPPOX by site-directed mutagenesis. They were screened for PPOX activity by complementation of the Escherischia coli strain SAS38X which lacks PPOX activity. Ten mutants (G40E, L85P, G232R, de1281H, V282D, L295P, V335G, S350P, L444P, G453V) had no detectable PPOX activity. PPOX activity of the remaining 12 mutants (L15F, R38P, L73P, V84G, D143V, R152C, L154P, V158M, R168H, A172V, V290L, G453R) ranged from less than 1% to 9.2% of wild-type activity. Our findings show that all 22 mutations substantially impair or abolish PPOX activity in a prokaryotic expression system and add to the evidence that they cause VP. PMID:11929051

Morgan, Rhian R; da, Silva Vasco; Puy, Hervé; Deybach, Jean-Charles; Elder, George H

2002-02-01

148

Monoamine oxidase A gene DNA hypomethylation - a risk factor for panic disorder?  

PubMed

The monoamine oxidase A (MAOA) gene has been suggested as a prime candidate in the pathogenesis of panic disorder. In the present study, DNA methylation patterns in the MAOA regulatory and exon 1/intron 1 region were investigated for association with panic disorder with particular attention to possible effects of gender and environmental factors. Sixty-five patients with panic disorder (44 females, 21 males) and 65 healthy controls were analysed for DNA methylation status at 42 MAOA CpG sites via direct sequencing of sodium bisulfate treated DNA extracted from blood cells. The occurrence of recent positive and negative life events was ascertained. Male subjects showed no or only very minor methylation with some evidence for relative hypomethylation at one CpG site in intron 1 in patients compared to controls. Female patients exhibited significantly lower methylation than healthy controls at 10 MAOA CpG sites in the promoter as well as in exon/intron 1, with significance surviving correction for multiple testing at four CpG sites (p?0.001). Furthermore, in female subjects the occurrence of negative life events was associated with relatively decreased methylation, while positive life events were associated with increased methylation. The present pilot data suggest a potential role of MAOA gene hypomethylation in the pathogenesis of panic disorder particularly in female patients, possibly mediating a detrimental influence of negative life events. Future studies are warranted to replicate the present finding in independent samples, preferably in a longitudinal design. PMID:22436428

Domschke, Katharina; Tidow, Nicola; Kuithan, Henriette; Schwarte, Kathrin; Klauke, Benedikt; Ambrée, Oliver; Reif, Andreas; Schmidt, Hartmut; Arolt, Volker; Kersting, Anette; Zwanzger, Peter; Deckert, Jürgen

2012-03-21

149

No mitochondrial cytochrome oxidase (COX) gene mutations in 18 cases of COX deficiency.  

PubMed

Cytochrome c oxidase (COX) deficiency causes a variety of neuromuscular and non-neuromuscular disorders in childhood and adulthood and can theoretically undergo either a nuclear or a mitochondrial (mt) mode of inheritance, making genetic counseling in COX deficiency particularly hazardous. In an attempt to determine the respective roles of mtDNA and nuclear DNA mutations in COX deficiency, we sequenced the three mitochondrially encoded COX subunits (COXI-III) in a series of 18 patients with isolated COX deficiency, especially as COXI-III code for the catalytic site of the enzyme. We failed to detect any deleterious mutations in this series. Moreover, no mtDNA deletion was observed and sequencing of the flanking tRNA genes involved in the maturation of the COX transcripts failed to detect deleterious mutations as well. The present study supports the view that the disease-causing mutations do not lie in the mt genome but, rather, in the nuclear genes encoding either the COX subunits or the proteins involved in assembly of the complex and suggests a recurrent risk of 25% rather than other modes of inheritance in COX deficiencies. PMID:9402980

Parfait, B; Percheron, A; Chretien, D; Rustin, P; Munnich, A; Rötig, A

1997-12-01

150

Molecular evolution of the cytochrome c oxidase subunit 5A gene in primates  

PubMed Central

Background Many electron transport chain (ETC) genes show accelerated rates of nonsynonymous nucleotide substitutions in anthropoid primate lineages, yet in non-anthropoid lineages the ETC proteins are typically highly conserved. Here, we test the hypothesis that COX5A, the ETC gene that encodes cytochrome c oxidase subunit 5A, shows a pattern of anthropoid-specific adaptive evolution, and investigate the distribution of this protein in catarrhine brains. Results In a dataset comprising 29 vertebrate taxa, including representatives from all major groups of primates, there is nearly 100% conservation of the COX5A amino acid sequence among extant, non-anthropoid placental mammals. The most recent common ancestor of these species lived about 100 million years (MY) ago. In contrast, anthropoid primates show markedly elevated rates of nonsynonymous evolution. In particular, branch site tests identify five positively selected codons in anthropoids, and ancestral reconstructions infer that substitutions in these codons occurred predominantly on stem lineages (anthropoid, ape and New World monkey) and on the human terminal branch. Examination of catarrhine brain samples by immunohistochemistry characterizes for the first time COX5A protein distribution in the primate neocortex, and suggests that the protein is most abundant in the mitochondria of large-size projection neurons. Real time quantitative PCR supports previous microarray results showing COX5A is expressed in cerebral cortical tissue at a higher level in human than in chimpanzee or gorilla. Conclusion Taken together, these results suggest that both protein structural and gene regulatory changes contributed to COX5A evolution during humankind's ancestry. Furthermore, these findings are consistent with the hypothesis that adaptations in ETC genes contributed to the emergence of the energetically expensive anthropoid neocortex.

2008-01-01

151

Structural organization and transcription regulation of nuclear genes encoding the mammalian cytochrome c oxidase complex.  

PubMed

Cytochrome c Oxidase (COX) is the terminal component of the bacterial as well as the mitochondrial respiratory chain complex that catalyzes the conversion of redox energy to ATP. In eukaryotes, the oligomeric enzyme is bound to mitochondrial innermembrane with subunits ranging from 7 to 13. Thus, its biosynthesis involves a coordinate interplay between nuclear and mitochondrial genomes. The largest subunits, I, II, and III, which represent the catalytic core of the enzyme, are encoded by the mitochondrial DNA and are synthesized within the mitochondria. The rest of the smaller subunits implicated in the regulatory function are encoded on the nuclear DNA and imported into mitochondria following their synthesis in the cytosol. Some of the nuclear coded subunits are expressed in tissue and developmental specific isologs. The ubiquitous subunits IV, Va, Vb, VIb, VIc, VIIb, VIIc, and VIII (L) are detected in all the tissues, although the mRNA levels for the individual subunits vary in different tissues. The tissue specific isologs VIa (H), VIIa (H), and VIII (H) are exclusive to heart and skeletal muscle. cDNA sequence analysis of nuclear coded subunits reveals 60 to 90% conservation among species both at the amino acid and nucleotide level, with the exception of subunit VIII, which exhibits 40 to 80% interspecies homology. Functional genes for COX subunits IV, Vb, VIa 'L' & 'H', VIIa 'L' & 'H', VIIc and VIII (H) from different mammalian species and their 5' flanking putative promoter regions have been sequenced and extensively characterized. The size of the genes range from 2 to 10 kb in length. Although the number of introns and exons are identical between different species for a given gene, the size varies across the species. A majority of COX genes investigated, with the exception of muscle-specific COXVIII(H) gene, lack the canonical 'TATAA' sequence and contain GC-rich sequences at the immediate upstream region of transcription start site(s). In this respect, the promoter structure of COX genes resemble those of many house-keeping genes. The ubiquitous COX genes show extensive 5' heterogeneity with multiple transcription initiation sites that bind to both general as well as specialized transcription factors such as YY1 and GABP (NRF2/ets). The transcription activity of the promoter in most of the ubiquitous genes is regulated by factors binding to the 5' upstream Sp1, NRF1, GABP (NRF2), and YY1 sites. Additionally, the murine COXVb promoter contains a negative regulatory region that encompasses the binding motifs with partial or full consensus to YY1, GTG, CArG, and ets. Interestingly, the muscle-specific COX genes contain a number of striated muscle-specific regulatory motifs such as E box, CArG, and MEF2 at the proximal promoter regions. While the regulation of COXVIa (H) gene involves factors binding to both MEF2 and E box in a skeletal muscle-specific fashion, the COXVIII (H) gene is regulated by factors binding to two tandomly duplicated E boxes in both skeletal and cardiac myocytes. The cardiac-specific factor has been suggested to be a novel bHLH protein. Mammalian COX genes provide a valuable system to study mechanisms of coordinated regulation of nuclear and mitochondrial genes. The presence of conserved sequence motifs common to several of the nuclear genes, which encode mitochondrial proteins, suggest a possible regulatory function by common physiological factors like heme/O2/carbon source. Thus, a well-orchestrated regulatory control and cross talks between the nuclear and mitochondrial genomes in response to changes in the mitochondrial metabolic conditions are key factors in the overall regulation of mitochondrial biogenesis. PMID:9752724

Lenka, N; Vijayasarathy, C; Mullick, J; Avadhani, N G

1998-01-01

152

Characteristics of NADPH oxidase genes (Nox2, p22, p47, and p67) and Nox4 gene expressed in blood cells of juvenile Ciona intestinalis  

Microsoft Academic Search

To illuminate the origins of NADPH oxidase (Nox), we identified cDNA clones encoding Nox2, Nox4, p22 phagocyte oxidase (phox),\\u000a p47phox, and p67phox in a chordate phylogenetically distant to the vertebrates, the sea squirt Ciona intestinalis. We also examined the spatiotemporal expression of these genes in embryos and juveniles. The sequences of the Nox2, Nox4,\\u000a p22phox, p47phox, and p67phox cDNAs contained

Yuuki Inoue; Michio Ogasawara; Takuma Moroi; Masanobu Satake; Kaoru Azumi; Tadaaki Moritomo; Teruyuki Nakanishi

2005-01-01

153

Mutations in the Arabidopsis gene IMMUTANS cause a variegated phenotype by inactivating a chloroplast terminal oxidase associated with phytoene desaturation.  

PubMed Central

The immutans (im) mutant of Arabidopsis shows a variegated phenotype comprising albino and green somatic sectors. We have cloned the IM gene by transposon tagging and show that even stable null alleles give rise to a variegated phenotype. The gene product has amino acid similarity to the mitochondrial alternative oxidase. We show that the IM protein is synthesized as a precursor polypeptide that is imported into chloroplasts and inserted into the thylakoid membrane. The albino sectors of im plants contain reduced levels of carotenoids and increased levels of the carotenoid precursor phytoene. The data presented here are consistent with a role for the IM protein as a cofactor for carotenoid desaturation. The suggested terminal oxidase function of IM appears to be essential to prevent photooxidative damage during early steps of chloroplast formation. We propose a model in which IM function is linked to phytoene desaturation and, possibly, to the respiratory activity of the chloroplast.

Carol, P; Stevenson, D; Bisanz, C; Breitenbach, J; Sandmann, G; Mache, R; Coupland, G; Kuntz, M

1999-01-01

154

Semicarbazide-sensitive amine oxidase (SSAO) gene expression in alloxan-induced diabetes in mice.  

PubMed Central

BACKGROUND: Plasma activity of semicarbazide-sensitive amine oxidase (SSAO) has been reported to be significantly higher in diabetic patients compared to healthy controls. Due to the production of highly angiotoxic substances in SSAO-catalyzed reactions, it has been speculated that this could be a cause for the vascular complications frequently associated with diabetes. Little is known about how the enzyme activity is regulated, and why it is high in these patients. In the present study, we assessed the possibility of transcriptional regulation by analyzing SSAO activity and SSAO-mRNA levels in mice with alloxan-induced diabetes. MATERIALS AND METHODS: Diabetes was induced in NMRI mice by a single intravenous injection of alloxan. The enzyme activity was analyzed by a radiometric assay using (14) C-benzylamine as a substrate, and the mRNA-levels were analyzed by real-time PCR. RESULTS: We found that the enzyme activity was increased in lung and adipose tissue 1 day after induction, as the glucose levels start to rise. Seven days after the injection of alloxan, the activity in serum was increased, and this activity was positively correlated with blood glucose levels in the alloxan-treated animals. Although the enzyme activity was increased in adipose tissue as a result of the treatment, SSAO-mRNA levels in this tissue were decreased, possibly suggesting a negative feedback on the gene expression. CONCLUSIONS: The main conclusion from this study is that the increased enzyme activity observed in diabetes is not a result of increased SSAO gene transcription. We speculate that the enzyme activity is controlled by posttranslational modifications of the protein, and that the catalytic activity controls the gene expression.

Nordquist, Jenny E. L.; Gokturk, Camilla; Oreland, Lars

2002-01-01

155

Expression of ACC oxidase genes differs among sex genotypes and sex phases in cucumber.  

PubMed

Ethylene has been implicated as a sex-determining hormone in cucumber: its exogenous application increases femaleness, and gynoecious genotypes were reported to produce more ethylene. In this study, three full-length ACC oxidase cDNAs were isolated from cucumber floral buds. RFLP analysis of a population that segregates for the F(femaleness) locus indicated that CS-ACO2 is linked to F at a distance of 8.7 cM. Expression of two of the genes, CS-ACO2 and CS-ACO3, was monitored in flowers, shoot tips and leaves of different sex genotypes. In situ mRNA hybridization indicated different patternsof tissue- and stage-specific expression of CS-ACO2 and CS-ACO3 in developing flowers. CS-ACO3 expression in mid-stage female flowers was localized to the nectaries, pistil and in the arrested staminoids, whereas CS-ACO2 transcript levels accumulated later and were found in placental tissue, ovary and staminoids. In male flowers, petals and nectaries expressed both genes, whereas ACO2 expression was strong in pollen of mature flowers. In young buds, strong expression was observed along developing vascular bundles. Four sex genotypes were compared for CS-ACO2 and CS-ACO3 expression in the shoot apex and young leaf. FF genotypes had higher transcript levels in leaves but lower levels in the shoot apex and in young buds, as compared to ff genotypes; the shoot-tip pattern is, therefore, inversely correlated with femaleness, and the possibility of a feedback inhibition mechanism underlying such correlation is discussed. The two CS-ACO genes studied displayed a differential response to ethrel treatment in different organs and sex genotypes, further demonstrating the complexity of the mechanisms controlling ethylene production during cucumber floral development. PMID:10608661

Kahana, A; Silberstein, L; Kessler, N; Goldstein, R S; Perl-Treves, R

1999-11-01

156

Decreased shoot stature and grain  -amylase activity following ectopic expression of a gibberellin 2-oxidase gene in transgenic wheat  

Microsoft Academic Search

Ectopic expression of a gibberellin 2-oxidase gene (PcGA2ox1) decreased the content of bioactive gibber- ellins (GAs) in transgenic wheat, producing a range of dwarf plants with different degrees of severity. In at least one case, a single transformation event gave rise to T1 plants with different degrees of dwarfism, the pheno- types being stably inherited over at least four genera-

Nigel E. J. Appleford; Mark D. Wilkinson; Qian Ma; Daniel J. Evans; Marlon C. Stone; Stephen P. Pearce; Stephen J. Powers; Stephen G. Thomas; Huw D. Jones; Andrew L. Phillips; Peter Hedden; John R. Lenton

2007-01-01

157

Disease Resistance Conferred by Expression of a Gene Encoding H2O2Generating Glucose Oxidase in Transgenic Potato Plants  

Microsoft Academic Search

Plant defense responses to pathogen infection involve the production of active oxygen species, including hydrogen peroxide (H202). We obtained transgenic potato plants expressing a funga1 gene encoding glucose oxidase, which generates H202 when glucose is oxidized. H2O2 levels were elevated in both leaf and tuber tissues of these plants. Transgenic potato tubers exhibited strong resistance to a bacterial soft rot

Gusui Wu; Barry J. Shortt; Ellen B. Lawrence; Elaine B. Levine; Karen C. Fitzsimmons; Dilip M. Shah

1995-01-01

158

Association between Single Nucleotide Polymorphisms in the Lysyl Oxidase-Like 1 Gene and Spontaneous Cervical Artery Dissection  

Microsoft Academic Search

Background: Spontaneous cervical artery dissection (sCAD) is a common cause of stroke in patients below 55 years. Dermal connective tissue abnormalities have been observed in up to 60% of patients. A chromosomal locus for connective tissue abnormalities associated with sCAD has been mapped to chromosome 15q24 to a candidate region containing the lysyl oxidase-like 1 gene (LOXL1). LOXL1 an excellent

G. Kuhlenbäumer; F. Friedrichs; B. Kis; P. Berlit; D. Maintz; I. Nassenstein; D. Nabavi; R. Dittrich; M. Stoll; B. Ringelstein

2007-01-01

159

Mitochondrial cytochrome c oxidase subunit 1 ( cox1) gene sequence of Spirocerca lupi (Nematoda, Spirurida): Avenues for potential implications  

Microsoft Academic Search

Canine spirocercosis is a life-threatening parasitosis caused by Spirocerca lupi (Nematoda, Spirurida) that is presently emerging in several countries. This study characterised an informative region within the mitochondrial (mtDNA) gene encoding for the cytochrome c oxidase subunit 1 (cox1) of S. lupi by Polymerase Chain Reaction (PCR)-coupled sequencing. Specimens from five different countries in Europe, Asia and Africa were examined

Donato Traversa; Francesca Costanzo; Raffaella Iorio; Itamar Aroch; Eran Lavy

2007-01-01

160

Cytochrome o (cyoABCDE) and d (cydAB) oxidase gene expression in Escherichia coli is regulated by oxygen, pH, and the fnr gene product  

SciTech Connect

The aerobic respiratory chain of Escherichia coli contains two terminal oxidases that catalyze the oxidation of ubiquinol-8 and the reduction of oxygen to water. They are the cytochrome o oxidase complex encoded by cyoABCDE and the cytochrome d oxidase complex encoded by cydAB. To determine how these genes are regulated in response to a variety of environmental stimuli, including oxygen, we examined their expression by using lacZ protein fusions in wild-type and fnr mutant strains of E. coli. Based on the pattern of anaerobic cydAB expression observed, we propose the existence of a second, as yet unidentified, regulatory element that must function either to activate cydAB expression as oxygen becomes limiting or to repress cydAB expression aerobically. Whereas cytochrome o oxidase encoded by cyoABCDE appears to be produced only under oxygen-rich growth conditions, in keeping with its biochemical properties, cytochrome d oxidase is expressed moderately aerobically and is elevated yet further when oxygen becomes limiting so that the organism can cope better under oxygen starvation conditions. We also examined cyoABCDE and cydAB expression in response to growth on alternative carbon compounds and to changes in the culture medium pH and osmolarity.

Cotter, P.A.; Gunsalus, R.P. (Univ. of California, Los Angeles (USA)); Chepuri, V.; Gennis, R.B. (Univ. of Illinois, Urbana (USA))

1990-11-01

161

Gene expression and distribution of antibacterial L-amino acid oxidase in the rockfish Sebastes schlegeli.  

PubMed

Antibacterial factors in the epidermal mucus of fish have a potential importance in the first line of the host defense response to bacterial pathogens. We previously isolated a novel antibacterial protein termed SSAP (Sebastes schlegeli antibacterial protein) from the skin mucus of the rockfish S. schlegeli and identified it as a new member of the L-amino acid oxidase (LAO) family. In the present study, the localization of SSAP in S. schlegeli was investigated by reverse transcription (RT)-PCR, quantitative real time RT-PCR, Western blotting and measurements of LAO and antibacterial activities. SSAP mRNA was expressed dominantly in skin and gill and weakly in ovary or kidney as shown by RT-PCR and real time RT-PCR. The quantity of SSAP mRNA in skin varied among the individuals, ranging from 1.1 to 13.9 ng microg(-1) total RNA, although no relationship was found between the size of fish and gene expression. SSAP was exclusively detected in skin and gill by Western blotting using a specific anti-SSAP antiserum. In addition, the extracts of both tissues apparently showed LAO activity and antibacterial activity against Photobacterium damselae subsp. piscicida. This study demonstrates that SSAP is predominantly synthesized in skin and gill and probably functions as an antibacterial LAO in both tissues. PMID:17964810

Kitani, Yoichiro; Mori, Tsukasa; Nagai, Hiroshi; Toyooka, Keiko; Ishizaki, Shoichiro; Shimakura, Kuniyoshi; Shiomi, Kazuo; Nagashima, Yuji

2007-05-03

162

The Gene Action and Function of Two Dopa Oxidase Positive Melanocyte Mutants of the Fowl  

PubMed Central

Ultrastructural and autoradiographic analysis revealed the developmental genetic differences between the dopa oxidase positive pk and I mutations of the fowl. The differences were revealed by the results of five measurements involving homozygous mutant melanocytes, heterozygous melanocytes, and standard melanocytes at each of the loci. The measurements were: ultrastructural comparisons of melanosomes in pigmented epithelial (PE) and neural crest derived (NC) melanocytes, the number of 3H-dopa and 3H-leucine grains/µ2 of melanosome, the 3H-dopa/3H-leucine ratio, and the percentage of cytoplasmic 3H-leucine grains that were melanosomal. The pk mutation altered both PE and NC melanosomes. +/pk melanocytes were characterized by suppressed 3H-dopa/µ2 and 3H-dopa/ 3H-leucine values. +/pk cells, however, had the same percentage of melanosomal 3H-leucine grains as the "pk" standard. The I mutation altered only NC melanosomes. +/I melanocytes were characterized by 3H-dopa/µ2 and 3H-dopa/ 3H-leucine values similar to the "I" standard. +/I cells had a lower percentage of melanosomal 3H-leucine grains than the "I" standard, however. These data suggest that pk is a structural mutation affecting melanin binding to the premelanosome, while I seems to be a control gene mutation partially suppressing the production of premelanosomal components in NC melanocytes.

Brumbaugh, J. A.; Lee, K. W.

1975-01-01

163

Role of Lysyl oxidase-like 1 gene polymorphisms in Pakistani patients with pseudoexfoliative glaucoma  

PubMed Central

Purpose Single nucleotide polymorphisms (SNPs) rs1048661 (p.R141L) and rs3825942 (p.G153D) in the lysyl oxidase-like 1 (LOXL1) gene have been previously reported to be associated with pseudoexfoliation glaucoma (PEXG) in various Asian and European populations, but these SNPs have not yet been studied in the Pakistani population. Therefore the aim of the present study was to investigate the association of these two coding LOXL1 SNPs in Pakistani PEXG patients. Methods One hundred twenty-eight Pakistani patients diagnosed with PEXG and 180 healthy controls were recruited for the study. Genomic DNA was extracted and both SNPs were genotyped by direct sequencing. Association of genotype and allele frequencies with PEXG were analyzed using the Chi-square (?2) test. Results Genotype and allele frequencies of both rs1048661 and rs3825942 were found to be significantly associated with PEXG. The GG genotypes of both LOXL1 SNPs were associated with an increased risk of developing PEXG. In addition the G alleles of rs1048661 and rs3825942 confer an increased risk for PEXG with an odds ratio (OR) of 2.98 (95% CI 1.94–4.57) and OR 6.83 (95% CI 2.94–16.67), respectively. Conclusions A significant association was found for the G allele of rs1048661 and rs3825942 in PEXG patients of Pakistani origin.

Micheal, Shazia; Khan, Muhammad Imran; Akhtar, Farah; Ali, Mahmood; Ahmed, Asifa; den Hollander, Anneke I.

2012-01-01

164

Identification of a founder mutation in the protoporphyrinogen oxidase gene in variegate porphyria patients from chile.  

PubMed

Variegate porphyria (VP; OMIM 176200) is characterized by a partial defect in the activity of protoporphyrinogen oxidase (PPO), the seventh enzyme of the porphyrin-heme biosynthetic pathway. The disease is usually inherited as an autosomal dominant trait displaying incomplete penetrance. In an effort to characterize the spectrum of molecular defects in VP, we identified 3 distinct mutations in 6 VP families from Chile by PCR, heteroduplex analysis, automated sequencing, restriction enzyme digestion and haplotyping analysis. The mutations consisted of 2 deletions and 1 missense mutation, designated 1239delTACAC, 1330delT and R168H. The occurrence of the missense mutation R168H had been reported previously in American, German and Dutch VP families, suggesting that this may represent a frequent recurrent mutation. Interestingly, the mutation 1239delTACAC was found in patients from 4 unrelated families living in different parts of Chile, suggesting that it might represent a common mutation in Chile. Haplotype analysis using 15 microsatellite markers which closely flank the PPO gene on chromosome 1q22, spanning approximately 21 cM, revealed the presence of R168H on different haplotypes in 6 VP patients from 3 unrelated families. In contrast, we found the occurrence of 1239delTACAC on the same chromosome 1 haplotype in 11 mutation carriers from 4 unrelated families with VP. These findings are consistent with R168H representing a hotspot mutation and 1239delTACAC existing as a founder mutation in the PPO gene. Our data comprise the first genetic studies of the porphyrias in South America and will streamline the elucidation of the genetic defects in VP patients from Chile by allowing an initial screening for the founder mutation 1239delTACAC. PMID:11173967

Frank, J; Aita, V M; Ahmad, W; Lam, H; Wolff, C; Christiano, A M

2001-01-01

165

Evidence for the possible existence of a remnant L-gulono-gamma-lactone oxidase (GULO) gene in a teleost genome.  

PubMed

DNA fragments related to the cloudy catshark Scyliorhinus torazame L-gulono-gamma-lactone oxidase (GULO) cDNA were detected in a distant fish species. Although the Southern hybridization pattern was more distinct in species with active GULO, DNA fragments related to the GULO gene were also discovered in the common carp Cyprinus carpio. Additionally, in the common carp, inter-individual variation of the hybridization pattern was observed. Regular screening of available teleost fish gene libraries did not reveal GULO related DNA sequences. PMID:20420195

Ocalewicz, Konrad; Dabrowski, Konrad; Mambrini, Muriel

2010-01-01

166

The sequence of the gene for cytochrome c oxidase subunit I, a frameshift containing gene for cytochrome c oxidase subunit II and seven unassigned reading frames in Trypanosoma brucei mitochrondrial maxi-circle DNA.  

PubMed Central

A 9.2 kb segment of the maxi-circle of Trypanosoma brucei mitochondrial DNA contains the genes for cytochrome c oxidase subunits I and II (coxI and coxII) and seven Unassigned Reading Frames ("URFs"). The genes for coxI and coxII display considerable homology at the aminoacid level (38 and 25%, respectively) to the corresponding genes in fungal and mammalian mtDNA, the only striking point of divergence being an unusually high cysteine content (about 4.5%). The reading frame coding for cytochrome c oxidase subunit II is discontinuous: the C-terminal portion of about 40 aminoacids, is present in the DNA-sequence in a -1 reading frame with respect to the N-terminal moiety. URF5, 8 and 10, show a low but distinct homology (about 20%) to mammalian mitochondrial URF-1, 4 and 5, respectively. In URF5, the first AUG is found at codon 145, whereas extensive homology to mammalian URF-1 sequences occurs upstream of this position. The possibility exists that UUG can serve as an initiator codon. URF7 and URF9 have a highly unusual aminoacid composition and do not possess AUG or UUG initiator codons. These URFs probably do not have a protein-coding function. The segment does not contain conventional tRNA genes. Images

Hensgens, L A; Brakenhoff, J; De Vries, B F; Sloof, P; Tromp, M C; Van Boom, J H; Benne, R

1984-01-01

167

Coordination of cytochrome c oxidase gene expression in the remodelling of skeletal muscle.  

PubMed

Many fish species respond to low temperature by inducing mitochondrial biogenesis, reflected in an increase in activity of the mitochondrial enzyme cytochrome c oxidase (COX). COX is composed of 13 subunits, three encoded by mitochondrial (mt)DNA and 10 encoded by nuclear genes. We used real-time PCR to measure mRNA levels for the 10 nuclear-encoded genes that are highly expressed in muscle. We measured mRNA levels in white muscle of three minnow species, each at two temperatures: zebrafish (Danio rerio) acclimated to 11 and 30°C, goldfish (Carassius auratus) acclimated to 4 and 35°C, and northern redbelly dace (Chrosomus eos) collected in winter and summer. We hypothesized that temperature-induced changes in COX activity would be paralleled by COX nuclear-encoded subunit transcript abundance. However, we found mRNA for COX subunits showed pronounced differences in thermal responses. Though zebrafish COX activity did not change in the cold, the transcript levels of four subunits decreased significantly (COX5A1, 60% decrease; COX6A2, 70% decrease; COX6C, 50% decrease; COX7B, 55% decrease). Treatments induced changes in COX activity in both dace (2.9 times in winter fish) and goldfish (2.5 times in cold fish), but the response in transcript levels was highly variable. Some subunits failed to increase in one (goldfish COX7A2, dace COX6A2) or both (COX7B, COX6B2) species. Other transcripts increased 1.7-100 times. The most cold-responsive subunits were COX4-1 (7 and 21.3 times higher in dace and goldfish, respectively), COX5A1 (13.9 and 5 times higher), COX6B1 (6 and 10 times higher), COX6C (11 and 4 times higher) and COX7C (13.3 and 100 times higher). The subunits that most closely paralleled COX increases in the cold were COX5B2 (dace 2.5 times, goldfish 1.7 times) and COX6A2 (dace 4.1 times, goldfish 1.7 times). Collectively, these studies suggest that COX gene expression is not tightly coordinated during cold-induced mitochondrial remodelling in fish muscle. Further, they caution against arguments about the importance of transcriptional regulation based on measurement of mRNA levels of select subunits of multimeric proteins. PMID:21562175

Duggan, Ana T; Kocha, Katrinka M; Monk, Christopher T; Bremer, Katharina; Moyes, Christopher D

2011-06-01

168

Expression and characterization of six mutations in the protoporphyrinogen oxidase gene among Finnish variegate porphyria patients.  

PubMed Central

BACKGROUND: Variegate porphyria (VP) is an inherited disorder of heme biosynthesis that results from a partial deficiency of protoporphyrinogen oxidase (PPOX). Patients with VP may experience acute neurovisceral attacks and cutaneous photosensitivity. To date we have characterized 109 VP patients representing 19 VP families in the Finnish population of 5 million, both biochemically and clinically. MATERIALS AND METHODS: Mutations were identified by direct sequencing of the patients' genomic DNA. The effect of the mutations was determined by sequencing the reverse transcriptase polymerase chain reaction (RT-PCR) product amplified from total RNA extracted from the patients' lymphoblast cell lines and expressing the mutations in E. coli and COS-1 cells. RESULTS: Of the six mutations identified in the PPOX gene, three mutations (IVS2-2a-->c, 338G-->C, and 470A-->4C) caused splicing defects, one produced a frameshift (78insC) and two mutations (R152C and L401F) caused amino acid substitutions. In RT-PCR, the IVS2-2a-->c mutation caused a retention of a 36-bp fragment in the 3' end of intron 2, the 338G-->C mutation caused an exon 4 deletion, and the 470A-->C mutation caused an exon 5 deletion with retention of a 19-bp fragment of the 3' end of intron 5. In both prokaryotic and eukaryotic expression systems, the PPOX activities of five mutants were decreased to 0-5% of the normal activity. CONCLUSIONS: This study describes five novel mutations and one earlier described major mutation among Finnish VP patients. All mutations produced detectable transcripts, but resulted in decreased PPOX activity confirming the causality of the mutations and the biochemical defects in these patients.

von und zu Fraunberg, M.; Tenhunen, R.; Kauppinen, R.

2001-01-01

169

Phylogeny of Apaturinae butterflies (Lepidoptera: Nymphalidae) based on mitochondrial cytochrome oxidase I gene.  

PubMed

The phylogenetic relationships of genera in the subfamily Apaturinae were examined using mtDNA sequence data from 1,471 bp of cytochrome oxidase subunit?(COI). The mitochondrial COI gene from a total of 16 species in 11 genera were sequenced to obtain mtDNA data, along with those of 4 species obtained from GenBank, to construct the MP and the NJ trees using Athyma jina, Penthema adelma, Polyura nepenthes, and Charaxes bernardus as outgroups. The transitions at the third codon positions of the COI data set were found saturated, but they were retained for analysis, because they contain the majority of the phylogenetic information. The impacts of equal weight assumptions for all characters in the parsimonious analysis were assessed by potential alternations in clades in response to different transition/transversion weighting schemes. The results indicated four distinct major groups in Apaturinae. Moreover, several well supported and stable clades were found in the Apaturinae. The study also identified undetermined taxon groups whose positions were weakly supported and were subject to changes under different weighting schemes. Within the Apaturinae, the clustering results are approximately identical to the classical morphological classification. The mtDNA data suggest the genus Mimathyma as a monophyletic group. Lelecella limenitoides and Dilipa fenestra have close relationship with very strong support in all phylogenetic trees. It also supports the taxonomic revision of removing several species from Apatura to other genera, namely Mimathyma schrenckii, M. chevana, M. nycteis, Chitoria subcaerulea, C. fasciola, C. pallas, and Helcyra subalba. PMID:17884691

Zhang, Min; Cao, Tianwen; Zhang, Rui; Guo, Yaping; Duan, Yihao; Ma, Enbo

2007-09-01

170

Expression of thiamin biosynthetic genes (thiCOGE) and production of symbiotic terminal oxidase cbb3 in Rhizobium etli.  

PubMed Central

In this paper we report the cloning and sequence analysis of four genes, located on plasmid pb, which are involved in the synthesis of thiamin in Rhizobium etli (thiC, thiO, thiG, and thiE). Two precursors, 4-methyl-5-(beta-hydroxyethyl)thiazole monophosphate and 4-amino-5-hydroxymethylpyrimidine pyrophosphate, are coupled to form thiamin monophosphate, which is then phosphorylated to make thiamin pyrophosphate. The first open reading frame (ORF) product, of 610 residues, has significant homology (69% identity) with the product of thiC from Escherichia coli, which is involved in the synthesis of hydroxymethylpyrimidine. The second ORF product, of 327 residues, is the product of a novel gene denoted thiO. A protein motif involved in flavin adenine dinucleotide binding was found in the amino-terminal part of ThiO; also, residues involved in the catalytic site of D-amino acid oxidases are conserved in ThiO, suggesting that it catalyzes the oxidative deamination of some intermediate of thiamin biosynthesis. The third ORF product, of 323 residues, has significant homology (38% identity) with ThiG from E. coli, which is involved in the synthesis of the thiazole. The fourth ORF product, of 204 residues, has significant homology (47% identity) with the product of thiE from E. coli, which is involved in the condensation of hydroxymethylpyrimidine and thiazole. Strain CFN037 is an R. etli mutant induced by a single Tn5mob insertion in the promoter region of the thiCOGE gene cluster. The Tn5mob insertion in CFN037 occurred within a 39-bp region which is highly conserved in all of the thiC promoters analyzed and promotes constitutive expression of thiC. Primer extension analysis showed that thiC transcription in strain CFN037 originates within the Tn5 element. Analysis of c-type protein content and expression of the fixNOQP operon, which codes for the symbiotic terminal oxidase cbb3, revealed that CFN037 produces the cbb3 terminal oxidase. These data show a direct relationship between expression of thiC and production of the cbb3 terminal oxidase. This is consistent with the proposition that a purine-related metabolite, 5-aminoimidazole-4-carboxamide ribonucleotide, is a negative effector of the production of the symbiotic terminal oxidase cbb3 in R. etli.

Miranda-Rios, J; Morera, C; Taboada, H; Davalos, A; Encarnacion, S; Mora, J; Soberon, M

1997-01-01

171

Cloning of a Novel Nicotine Oxidase Gene from Pseudomonas sp. Strain HZN6 Whose Product Nonenantioselectively Degrades Nicotine to Pseudooxynicotine  

PubMed Central

Pseudomonas sp. strain HZN6 utilizes nicotine as its sole source of carbon, nitrogen, and energy. However, its catabolic mechanism has not been elucidated. In this study, self-formed adaptor PCR was performed to amplify the upstream sequence of the pseudooxynicotine amine oxidase gene. A 1,437-bp open reading frame (designated nox) was found to encode a nicotine oxidase (NOX) that shows 30% amino acid sequence identity with 6-hydroxy-l-nicotine oxidase from Arthrobacter nicotinovorans. The nox gene was cloned into a broad-host-range cloning vector and transferred into the non-nicotine-degrading bacteria Escherichia coli DH5? (DH-nox) and Pseudomonas putida KT2440 (KT-nox). The transconjugant KT-nox obtained nicotine degradation ability and yielded an equimolar amount of pseudooxynicotine, while DH-nox did not. Reverse transcription-PCR showed that the nox gene is expressed in both DH5? and KT2440, suggesting that additional factors required for nicotine degradation are present in a Pseudomonas strain(s), but not in E. coli. The mutant of strain HZN6 with nox disrupted lost the ability to degrade nicotine, but not pseudooxynicotine. These results suggested that the nox gene is responsible for the first step of nicotine degradation. The (RS)-nicotine degradation results showed that the two enantiomers were degraded at approximately the same rate, indicating that NOX does not show chiral selectivity. Site-directed mutagenesis revealed that both the conserved flavin adenine dinucleotide (FAD)-binding GXGXXG motif and His456 are essential for nicotine degradation activity.

Qiu, Jiguo; Ma, Yun; Zhang, Jing; Wen, Yuezhong

2013-01-01

172

Transcriptional activation of the alternative oxidase gene of the fungus Magnaporthe grisea by a respiratory-inhibiting fungicide and hydrogen peroxide  

Microsoft Academic Search

Alternative oxidase (AOX) is dramatically induced when the fungus Magnaporthe grisea is incubated with the fungicide SSF-126, which interacts with the cytochrome bc1 complex in the electron transport system of mitochondria. A full-length cDNA for the alternative oxidase gene (AOX) was obtained, and the deduced amino acid sequence revealed marked similarity to other AOXs, but lacks two cysteine residues at

Hideo Yukioka; Shuichiro Inagaki; Reiji Tanaka; Kenji Katoh; Nobuo Miki; Akira Mizutani; Michio Masuko

1998-01-01

173

Cloning and Molecular Analyses of a Gibberellin 20-Oxidase Gene Expressed Specifically in Developing Seeds of Watermelon1  

PubMed Central

To understand the biosynthesis and functional role of gibberellins (GAs) in developing seeds, we isolated Cv20ox, a cDNA clone from watermelon (Citrullus lanatus) that shows significant amino acid homology with GA 20-oxidases. The complementary DNA clone was expressed in Escherichia coli as a fusion protein, which oxidized GA12 at C-20 to the C19 compound GA9, a precursor of bioactive GAs. RNA-blot analysis showed that the Cv20ox gene was expressed specifically in developing seeds. The gene was strongly expressed in the integument tissues, and it was also expressed weakly in inner seed tissues. In parthenocarpic fruits induced by 1-(2-chloro-4-pyridyl)-3-phenylurea treatment, the expression pattern of Cv20ox did not change, indicating that the GA 20-oxidase gene is expressed primarily in the maternal cells of developing seeds. The promoter of Cv20ox was isolated and fused to the ?-glucuronidase (GUS) gene. In a transient expression system, ?-glucuronidase staining was detectable only in the integument tissues of developing watermelon seeds.

Kang, Hong-Gyu; Jun, Sung-Hoon; Kim, Junyul; Kawaide, Hiroshi; Kamiya, Yuji; An, Gynheung

1999-01-01

174

Cloning and molecular analyses of a gibberellin 20-oxidase gene expressed specifically in developing seeds of watermelon.  

PubMed

To understand the biosynthesis and functional role of gibberellins (GAs) in developing seeds, we isolated Cv20ox, a cDNA clone from watermelon (Citrullus lanatus) that shows significant amino acid homology with GA 20-oxidases. The complementary DNA clone was expressed in Escherichia coli as a fusion protein, which oxidized GA(12) at C-20 to the C(19) compound GA(9), a precursor of bioactive GAs. RNA-blot analysis showed that the Cv20ox gene was expressed specifically in developing seeds. The gene was strongly expressed in the integument tissues, and it was also expressed weakly in inner seed tissues. In parthenocarpic fruits induced by 1-(2-chloro-4-pyridyl)-3-phenylurea treatment, the expression pattern of Cv20ox did not change, indicating that the GA 20-oxidase gene is expressed primarily in the maternal cells of developing seeds. The promoter of Cv20ox was isolated and fused to the beta-glucuronidase (GUS) gene. In a transient expression system, beta-glucuronidase staining was detectable only in the integument tissues of developing watermelon seeds. PMID:10517828

Kang, H G; Jun, S H; Kim, J; Kawaide, H; Kamiya, Y; An, G

1999-10-01

175

Systematic screening of lysyl oxidase-like (LOXL) family genes demonstrates that LOXL2 is a susceptibility gene to intracranial aneurysms  

Microsoft Academic Search

Four lysyl oxidase family genes (LOXL1, LOXL2, LOXL3, and LOXL4), which catalyze cross-linking of collagen and elastin, were considered to be functional candidates for intracranial aneurysms\\u000a (IA) and were extensively screened for genetic susceptibility in Japanese IA patients. Total RNA was isolated from four paired\\u000a ruptured IA and superficial temporal artery (STA) tissue and examined by real-time RT-PCR. The expression

Hiroyuki Akagawa; Akira Narita; Haruhiko Yamada; Atsushi Tajima; Boris Krischek; Hidetoshi Kasuya; Tomokatsu Hori; Motoo Kubota; Naokatsu Saeki; Akira Hata; Tohru Mizutani; Ituro Inoue

2007-01-01

176

Hereditary Coproporphyria Associated with the Q306X Mutation in the Coproporphyrin Oxidase Gene Presenting with Acute Ataxia  

PubMed Central

Background Hereditary coproporphyria (HCPO) is a low-penetrance, autosomal dominant, acute hepatic porphyria characterized by the overproduction and excretion of coproporphyrin. The most common neurological manifestations of this entity include peripheral, predominantly motor dysfunction, and central nervous system dysfunction. Ataxia associated with HCPO has not been reported previously. The aim of this article is to report a patient with HCPO presenting with acute ataxia. Case Report We describe a 44-year-old patient presenting clinically with acute ataxia who was diagnosed with HCPO; mutations were analyzed in the coproporphyrin-oxidase III (CPOX) gene in the patient and in six asymptomatic first-degree relatives. Discussion The patient was heterozygous for a mutation causing the amino acid exchange Q306X in the CPOX gene. No relatives carried the same or another mutation in the CPOX gene. HCPO should be considered in the differential diagnosis for patients presenting with ataxia.

Jimenez-Jimenez, Felix Javier; Agundez, Jose A. G.; Martinez, Carmen; Navacerrada, Francisco; Plaza-Nieto, Jose Francisco; Pilo-de-la-Fuente, Belen; Alonso-Navarro, Hortensia; Garcia-Martin, Elena

2013-01-01

177

A human homologue of the Drosophila melanogaster sluggish-A (proline oxidase) gene maps to 22q11.2, and is a candidate gene for type-I hyperprolinaemia  

Microsoft Academic Search

We have cloned the complete coding region for a human homologue of the Drosophila melanogaster sluggish-A and yeast PUT1 genes, previously shown to encode proline oxidase activity in these organisms. The predicted 516-residue human protein shows\\u000a strong homology (51% amino acid sequence identity) to the D. melanogaster protein, indicating that this new human gene may encode proline oxidase. Northern analysis

Hugh D. Campbell; Graham C. Webb; Ian G. Young

1997-01-01

178

Evaluation of lysyl oxidase-like 1 gene polymorphisms in pseudoexfoliation syndrome in a Korean population  

PubMed Central

Purpose The purpose of this study was to evaluate association profiles of lysyl oxidase-like 1 (LOXL1) gene polymorphisms with pseudoexfoliation syndrome (XFS) in a Korean population. Methods A total of 110 Korean patients with XFS and 127 control subjects were included in this study. Genotypes of three single nucleotide polymorphisms (SNPs) of LOXL1 (rs1048661, rs3825942, and rs2165241) were analyzed with direct sequencing, and a case-control association study was performed. Genotype frequencies of each SNP were compared according to the XFS phenotypes. Results All three SNPs were significantly associated with XFS. The T allele at rs1048661 (odds ratio [OR]=14.29, 95% confidence interval [CI]=6.25–33.3) and the C allele at rs2165241 (OR=7.14, 95% CI=1.59–33.3) were risk alleles in Korean subjects, which was consistent with findings in other Asian populations. However, our findings were opposite to results from Caucasian populations in which the risk alleles at rs1048661 and rs2165241 were G and T, respectively. At the rs3825942, the G allele (OR=12.50, 95% CI=2.94–50.0) was a risk allele for XFS, which was similar to results from most other ethnic groups except black South Africans in whom the A allele increased the risk. In the haplotype analysis, the T-G-C haplotype composed of all three risk alleles was significantly overrepresented in XFS and conferred an 11.36 fold (95% CI=5.97–23.49) increased likelihood of XFS. There was no significant association between the genotype frequencies of the three SNPs and the XFS phenotypes. Conclusions Three SNPs of LOXL1 (rs1048661, rs3825942, and 2,165,241) are highly associated with XFS in a Korean population. The risk alleles of these SNPs were similar to those of other Asian populations, such as Japanese or Chinese, but differed from non-Asian populations, suggesting that still unidentified genetic or environmental factors may contribute to disease expression.

Park, Do Young; Won, Hong-Hee; Cho, Hyun-kyung

2013-01-01

179

Species differences in the temporal pattern of Drosophila urate oxidase gene expression are attributed to trans-acting regulatory changes.  

PubMed Central

The Drosophila melanogaster urate oxidase (UO)-encoding gene is expressed in the third-instar larva and adult. In contrast, the Drosophila pseudoobscura UO gene is only expressed in the adult, whereas the Drosophila virilis UO gene is expressed only in the third-instar larva. UO activity in these three Drosophila species is detected exclusively within the Malpighian tubules. By using P-element mediated germ-line transformation, UO genes from D. pseudoobscura and D. virilis were integrated into the D. melanogaster genome. The D. virilis and D. pseudoobscura UO transgenes were expressed in the third-instar larva and adult Malpighian tubules, which is the D. melanogaster temporal pattern of UO gene expression. These observations indicate that differences in the temporal patterns of regulation of UO genes among these three Drosophila species are not likely to be due to evolutionary changes in the sequence or complement of UO cis-acting regulatory elements. The species differences in UO regulation are probably the result of changes in one or more trans-acting factors required for UO gene expression in the third-instar larval and adult stages. Images

Wallrath, L L; Friedman, T B

1991-01-01

180

Isolation of the human peroxisomal acyl-CoA oxidase gene: organization, promoter analysis, and chromosomal localization.  

PubMed Central

Peroxisomal acyl-CoA oxidase (ACOX; EC 1.3.3.6) is the first enzyme of the fatty acid beta-oxidation pathway, which catalyzes the desaturation of acyl-CoAs to 2-trans-enoyl-CoAs, and it donates electrons directly to molecular oxygen, thereby producing H2O2. The discovery of carcinogenic peroxisome proliferators, which markedly increase the levels of this H2O2-producing ACOX in rat and mouse liver, generated interest in peroxisomal beta-oxidation system genes. The present study deals with the structural organization of human ACOX gene. This gene spans approximately 33 kb and consists of 14 exons and 13 introns. Primer-extension analysis revealed three principal cap sites, which were mapped at 50, 52, and 53 nt upstream of the initiator methionine codon. The 5' flanking region of the ACOX gene was sequenced up to 500 bp upstream of the cap sites. This promoter region is G + C-rich and contains three copies of the "GC box" hexanucleotides. Multiple GC boxes are a characteristic feature of the rat ACOX and bifunctional protein genes of the beta-oxidation system. A + T-rich TATA-boxlike sequences, TTTATTT and TTATT, have also been identified in this human ACOX gene, but typical CCAAT motifs are absent. This ACOX gene has been mapped to chromosome 17q25 by in situ hybridization, using a biotinlabeled probe. Images

Varanasi, U; Chu, R; Chu, S; Espinosa, R; LeBeau, M M; Reddy, J K

1994-01-01

181

Mutations in the human SC4MOL gene encoding a methyl sterol oxidase cause psoriasiform dermatitis, microcephaly, and developmental delay.  

PubMed

Defects in cholesterol synthesis result in a wide variety of symptoms, from neonatal lethality to the relatively mild dysmorphic features and developmental delay found in individuals with Smith-Lemli-Opitz syndrome. We report here the identification of mutations in sterol-C4-methyl oxidase–like gene (SC4MOL) as the cause of an autosomal recessive syndrome in a human patient with psoriasiform dermatitis, arthralgias, congenital cataracts, microcephaly, and developmental delay. This gene encodes a sterol-C4-methyl oxidase (SMO), which catalyzes demethylation of C4-methylsterols in the cholesterol synthesis pathway. C4-Methylsterols are meiosis-activating sterols (MASs). They exist at high concentrations in the testis and ovary and play roles in meiosis activation. In this study, we found that an accumulation of MASs in the patient led to cell overproliferation in both skin and blood. SMO deficiency also substantially altered immunocyte phenotype and in vitro function. MASs serve as ligands for liver X receptors ? and ?(LXR? and LXR?), which are important in regulating not only lipid transport in the epidermis, but also innate and adaptive immunity. Deficiency of SMO represents a biochemical defect in the cholesterol synthesis pathway, the clinical spectrum of which remains to be defined. PMID:21285510

He, Miao; Kratz, Lisa E; Michel, Joshua J; Vallejo, Abbe N; Ferris, Laura; Kelley, Richard I; Hoover, Jacqueline J; Jukic, Drazen; Gibson, K Michael; Wolfe, Lynne A; Ramachandran, Dhanya; Zwick, Michael E; Vockley, Jerry

2011-03-01

182

glcLocus ofEscherichia coli: Characterization of Genes Encoding the Subunits of Glycolate Oxidase and theglcRegulator Protein  

Microsoft Academic Search

Thelocusglc(min64.5),associatedwiththeglycolateutilizationtraitinEscherichiacoli,isknowntocontain glcB, encoding malate synthase G, and the gene(s) needed for glycolate oxidase activity. Subcloning, sequenc- ing,insertionmutagenesis,andexpressionstudiesshowedfiveadditionalgenes:glcCandintheotherdirection glcD,glcE,glcF, andglcGfollowed byglcB. The geneglcCmay encode theglcregulator protein. Consistently a chloramphenicol acetyltransferase insertion mutation abolished both glycolate oxidase and malate synthase G activities. The proteins encoded fromglcDandglcEdisplayed similarity to severalflavoenzymes, the one from glcF was found to be similar to iron-sulfur proteins, and

MARIA-TERESA PELLICER; JOSEFA BADIA; JUAN AGUILAR

183

High-level expression of the Penicillium notatum glucose oxidase gene in Pichia pastoris using codon optimization.  

PubMed

The glucose oxidase (GOD) gene from Penicillium notatum was expressed in Pichia pastoris. The 1,815 bp gene, god-w, encodes 604 amino acids. Recombinant GOD-w had optimal activity at 35-40°C and pH 6.2 and was stable, from pH 3 to 7 maintaining >75% maximum activity after incubation at 50°C for 1 h. GOD-w worked as well as commercial GODs to improve bread making. To achieve high-level expression of recombinant GOD in P. pastoris, 272 nucleotides involving 228 residues were mutated, consistent with the codon bias of P. pastoris. The optimized recombinant GOD-m yielded 615 U ml(-1) (2.5 g protein l(-1)) in a 3 l fermentor--410% higher than GOD-w (148 U ml(-1)), and thus is a low-cost alternative for the bread baking industry. PMID:22052258

Gao, Zhaowei; Li, Zhuofu; Zhang, Yuhong; Huang, Huoqing; Li, Mu; Zhou, Liwei; Tang, Yunming; Yao, Bin; Zhang, Wei

2011-11-04

184

Evidence for a genetic association between alleles of monoamine oxidase A gene and bipolar affective disorder  

SciTech Connect

We present evidence of a genetic association between bipolar disorder and alleles at 3 monoamine oxidase A (MAOA) markers, but not with alleles of a monoamine oxidase B (MAOB) polymorphism. The 3 MAOA markers, including one associated with low MAOA activity, show strong allelic association with each other but surprisingly not with MAOB. Our results are significantly only for females, though the number of males in our sample is too small to draw any definite conclusions. Our data is consistent with recent reports of reduced MAOA activity in patients with abnormal behavioral phenotypes. The strength of the association is weak, but significant, which suggests that alleles at the MAOA locus contribute to susceptibility to bipolar disorder rather than being a major determinant. 58 refs., 1 fig., 3 tabs.

Lim, L.C.C.; Sham, P.; Castle, D. [Institute of Psychiatry, London (United Kingdom)] [and others

1995-08-14

185

Genetic mapping of the gene affecting polyphenol oxidase activity in tetraploid durum wheat  

Microsoft Academic Search

The quality of durum wheat (Triticum turgidum ssp.durum) is influenced by polyphenol oxidase (PPO) activity and its corresponding substrates. A saturated molecular-marker linkage\\u000a map was constructed previously by using a set of recombinant inbred (RI) lines, derived from a cross between durum wheat cultivars\\u000a Jennah Khetifa and Cham 1. Quantitative trait loci (QTL) for PPO activity in seeds were mapped

Nobuyoshi Watanabe; A. S. M. G. Masum Akond; Miloudi M. Nachit

2006-01-01

186

Expression of ACC oxidase genes differs among sex genotypes and sex phases in cucumber  

Microsoft Academic Search

Ethylene has been implicated as a sex-determining hormone in cucumber: its exogenous application increases femaleness, and gynoecious genotypes were reported to produce more ethylene. In this study, three full-length ACC oxidase cDNAs were isolated from cucumber floral buds. RFLP analysis of a population that segregates for the F (femaleness) locus indicated that CS-ACO2 is linked to F at a distance

Anat Kahana; Leah Silberstein; Naama Kessler; Ronald S. Goldstein; Rafael Perl-Treves

1999-01-01

187

Functional gene markers for polyphenol oxidase locus in bread wheat ( Triticum aestivum L.)  

Microsoft Academic Search

Higher polyphenol oxidase (PPO) activity in wheat kernels and flour has been implicated in the time dependent darkening of\\u000a various end-products. Previous study conducted on a bread wheat (Triticum aestivum L.) doubled haploid (DH) mapping population derived from Chara (medium-high PPO) and WW2449 (low PPO) identified a major\\u000a QTL for PPO activity located on the long arm of chromosome 2A.

Rosy Raman; Harsh Raman; Peter Martin

2007-01-01

188

Monoamine oxidase-A polymorphisms might modify the association between the dopamine D2receptor gene and alcohol dependence  

PubMed Central

Objective Low monoamine oxidase (MAO) activity and the neurotransmitter dopamine are 2 important factors in the development of alcohol dependence. MAO is an important enzyme associated with the metabolism of biogenic amines. Therefore, the present study investigates whether the association between the dopamine D2 receptor (DRD2) gene and alcoholism is affected by different polymorphisms of the MAO type A (MAOA) gene. Methods A total of 427 Han Chinese men in Taiwan (201 control subjects and 226 with alcoholism) were recruited for the study. Of the subjects with alcoholism, 108 had pure alcohol dependence (ALC) and 118 had both alcohol dependence and anxiety, depression or both (ANX/DEP ALC). All subjects were assessed with the Chinese Version of the Modified Schedule of Affective Disorders and Schizophrenia-Lifetime. Alcohol dependence, anxiety and major depressive disorders were diagnosed according to Diagnostic and Statistical Manual of Mental Disorders, fourth edition criteria. Conclusion The genetic variant of the DRD2 gene was only associated with the ANX/DEP ALC phenotype, and the genetic variant of the MAOA gene was associated with pure ALC. Subjects carrying the MAOA 3-repeat allele and genotype A1/A1 of the DRD2 were 3.48 times (95% confidence interval = 1.47–8.25) more likely to be ANX/DEP ALC than the subjects carrying the MAOA 3-repeat allele and DRD2 A2/A2 genotype. The MAOA gene may modify the association between the DRD2 gene and ANX/DEP ALC phenotype.

Huang, San-Yuan; Lin, Wei-Wen; Wan, Fang-Jung; Chang, Ai-Ju; Ko, Huei-Chen; Wang, Tso-Jen; Wu, Pei-Lin; Lu, Ru-Band

2007-01-01

189

Molecular characterization and chromosome assignment of the porcine gene COX7A1 coding for the muscle specific cytochrome c oxidase subunit VIIa-M  

Microsoft Academic Search

The COX7A1 gene encodes a heart- and muscle-specific isoform of the subunit VIIA of cytochrome c oxidase, which is the last component of the mitochondrial electron transfer chain. Cloning and characterization of the porcine COX7A1 gene revealed a highly conserved organization with respect to other mammalian COX7A1 orthologs. The porcine gene consists of four exons spanning approximately 1.5 kb and

C. Drögemüller; H. Kuiper; R. Voß-Nemitz; B. Brenig; O. Distl; T. Leeb

2001-01-01

190

Molecular Cloning and Functional Characterization of the Dual Oxidase (BmDuox) Gene from the Silkworm Bombyx mori.  

PubMed

Reactive oxygen species (ROS) from nicotinamide adenine dinucleotide phosphate (NADPH) oxidases and their related dual oxidases are known to have significant roles in innate immunity and cell proliferation. In this study, the 5,545 bp cDNA of the silkworm Bombyx mori dual oxidase (BmDuox) gene containing a full-length open reading frame was cloned. It was shown to include an N-terminal signal peptide consisting of 28 amino acid residues, a 240 bp 5'-terminal untranslated region (5'-UTR), an 802 bp 3'-terminal region (3'-UTR), which contains nine ATTTA motifs, and a 4,503 bp open reading frame encoding a polypeptide of 1,500 amino acid residues. Structural analysis indicated that BmDuox contains a typical peroxidase domain at the N-terminus followed by a calcium-binding domain, a ferric-reducing domain, six transmembrane regions and binding domains for flavin adenine dinucleotide (FAD) and nicotinamide adenine dinucleotide (NAD). Transcriptional analysis revealed that BmDuox mRNA was expressed more highly in the head, testis and trachea compared to the midgut, hemocyte, Malpighian tube, ovary, fat bodies and silk glands. BmDuox mRNA was expressed during all the developmental stages of the silkworm. Subcellular localization revealed that BmDoux was present mainly in the periphery of the cells. Some cytoplasmic staining was detected, with rare signals in the nucleus. Expression of BmDuox was induced significantly in the larval midgut upon challenge by Escherichia coli and Bombyx mori nucleopolyhedrovirus (BmNPV). BmDuox-deleted larvae showed a marked increase in microbial proliferation in the midgut after ingestion of fluorescence-labeled bacteria compared to the control. We conclude that reducing BmDuox expression greatly increased the bacterial load, suggesting BmDuox has an important role in inhibiting microbial proliferation and the maintenance of homeostasis in the silkworm midgut. PMID:23936382

Hu, Xiaolong; Yang, Rui; Zhang, Xing; Chen, Lin; Xiang, Xingwei; Gong, Chengliang; Wu, Xiaofeng

2013-08-02

191

Genomic sequence and organization of the human gene for cytochrome c oxidase subunit (COX7A1) VIIa-M.  

PubMed

Cytochrome c oxidase (COX, EC 1.9.3.1), the last component of the mitochondrial electron transfer chain, is built up by 13 polypeptides; 3 of them are encoded by the mitochondrial genome while the 10 smaller subunits are encoded by the nuclear genome. Several nuclear-encoded subunits occur in two different tissue-specific isoforms, a constitutive "L"-form and an "M"-form specific for skeletal and heart muscle. In this article, we describe the genomic sequence and organization of the human gene for COX subunit VIIa-M (COX7A1) located on chromosome 19q13.1 and compare it to its bovine homologue. The coding region of the gene extends over 1.45 kb of genomic sequence, organized in four exons. Intron-exon boundaries are well conserved between cattle and humans. Although it is a gene for a tissue-specific isoform, it has some features of a housekeeping gene: it is located in a CpG island, like its bovine homologue, and no TATA or CCAAT boxes were found in the 5' flanking sequence. Southern hybridization of COX7A1 to human genomic DNA revealed no pseudogenes. Putative binding sites for ubiquitous transcription factors like Sp1 and specific expression in skeletal as well as in heart muscle have been found. In contrast to the bovine gene, the human gene contains putative binding sites for nuclear respiratory factor 2 (NRF-2), which is implicated in the activation of other respiratory enzymes. Therefore, the human and the bovine genes, although well conserved in their coding regions, could differ in the tissue-specific regulation of gene expression. Knowledge of the gene structure will facilitate the analysis of the involvement of subunit VIIa in mitochondrial myopathies and may provide clues to the function of this subunit in a multicomponent enzyme. PMID:9344674

Wolz, W; Kress, W; Mueller, C R

1997-10-15

192

Functionally undefined gene, yggE, alleviates oxidative stress generated by monoamine oxidase in recombinant Escherichia coli.  

PubMed

Real-time PCR analysis showed that yggE gene was about two and three times up-regulated in Escherichia coli cells exposed to UVA irradiation and thermal elevation, respectively, suggesting that this gene is responsive to physiological stress. The yggE gene was introduced into E. coli BL21 cells, together with a monoamine oxidase (MAO) gene as a model source for oxidative stress generation. The distribution of independently isolated transformants (two dozen isolates) was examined in terms of MAO activity and cell vitality. In the case of control strain expressing MAO alone, the largest number of transformants existed in the low range of MAO activity less than 2 units mg(-1) and the number significantly decreased at increased MAO activity. On the other hand, the distribution of MAO/YggE-coexpressing transformants shifted to higher MAO activity with frequent appearance in the activity range of 4-8 units mg(-1). The yggE gene product therefore has a possible function for alleviating the stress generated in the cells. PMID:18800193

Ojima, Yoshihiro; Kawase, Daisuke; Nishioka, Motomu; Taya, Masahito

2008-09-18

193

Structural organization and promoter analysis of the bovine cytochrome c oxidase subunit VIIc gene. A functional role for YY1.  

PubMed

Cytochrome c oxidase (COX) subunit VIIc is one of the nuclear encoded subunits of the 13-subunit holoenzyme that carries out the terminal step in the electron transport chain. We have isolated the gene for this subunit, previously shown to be ubiquitously expressed from a single copy gene in the genome, and show that 167 base pairs of DNA surrounding the transcriptional start site contain the minimal promoter of this gene. This basal promoter contains two YY1 sites and at least one site for NRF-2, which show binding to their cognate factors. Mutation of both YY1 sites eliminates most of the promoter activity. Mutation at the upstream YY1 site significantly reduces the efficiency of transcript initiation at the major start site and thus plays the dominant role in COX7C regulation. COX7C is, thus, the second nuclear gene of COX that is regulated by YY1, suggesting that it is a third common factor, along with NRF-1 and NRF-2, to be associated with COX gene regulation. PMID:9092564

Seelan, R S; Grossman, L I

1997-04-11

194

Evolutionary Dynamics of the Human NADPH Oxidase Genes CYBB, CYBA, NCF2, and NCF4: Functional Implications.  

PubMed

The phagocyte NADPH oxidase catalyzes the reduction of O2 to reactive oxygen species with microbicidal activity. It is composed of two membrane-spanning subunits, gp91-phox and p22-phox (encoded by CYBB and CYBA, respectively), and three cytoplasmic subunits, p40-phox, p47-phox, and p67-phox (encoded by NCF4, NCF1, and NCF2, respectively). Mutations in any of these genes can result in chronic granulomatous disease, a primary immunodeficiency characterized by recurrent infections. Using evolutionary mapping, we determined that episodes of adaptive natural selection have shaped the extracellular portion of gp91-phox during the evolution of mammals, which suggests that this region may have a function in host-pathogen interactions. On the basis of a resequencing analysis of approximately 35 kb of CYBB, CYBA, NCF2, and NCF4 in 102 ethnically diverse individuals (24 of African ancestry, 31 of European ancestry, 24 of Asian/Oceanians, and 23 US Hispanics), we show that the pattern of CYBA diversity is compatible with balancing natural selection, perhaps mediated by catalase-positive pathogens. NCF2 in Asian populations shows a pattern of diversity characterized by a differentiated haplotype structure. Our study provides insight into the role of pathogen-driven natural selection in an innate immune pathway and sheds light on the role of CYBA in endothelial, nonphagocytic NADPH oxidases, which are relevant in the pathogenesis of cardiovascular and other complex diseases. PMID:23821607

Tarazona-Santos, Eduardo; Machado, Moara; Magalhães, Wagner C S; Chen, Renee; Lyon, Fernanda; Burdett, Laurie; Crenshaw, Andrew; Fabbri, Cristina; Pereira, Latife; Pinto, Laelia; Redondo, Rodrigo A F; Sestanovich, Ben; Yeager, Meredith; Chanock, Stephen J

2013-07-02

195

Selective upregulation and amplification of the lysyl oxidase like-4 (LOXL4) gene in head and neck squamous cell carcinoma.  

PubMed

Members of the lysyl oxidase family (LOX) are copper and lysyl-tyrosine quinone cofactor-containing amine oxidases that are important for the assembly and maintenance of components of the extracellular matrix. Our previous results demonstrated that a novel member, LOXL4, is overexpressed in head and neck squamous cell carcinoma (HNSCC) compared to normal squamous epithelium. Results of the current study showed overexpression of the LOXL4 transcript in 74% (46 of 62) of invasive HNSCC tumours and 90% of both primary and metastatic HNSCC cell lines. Significant correlation was found between LOXL4 expression and local lymph node metastases versus primary tumour types (p<0.01) and higher tumour stages (p<0.01). Immunocytochemistry demonstrated cellular overexpression of the LOXL4 protein that correlated with the increased mRNA transcription in HNSCC cells. HNSCC cell lines displayed in significant subset of nuclei increased copies of the LOX4 gene locus on chromosome 10q24, demonstrated by fluorescence in situ hybridization (FISH). Extensive metaphase cytogenetic analysis was performed on UTSCC19A cells, identifying an isochromosome i(10)(q10). Taken together, these results highlight LOXL4 expression as a distinctive trait and suggest a functional role for LOXL4 in the molecular pathogenesis of invasive head and neck carcinomas. PMID:17354256

Görögh, T; Weise, J B; Holtmeier, C; Rudolph, P; Hedderich, J; Gottschlich, S; Hoffmann, M; Ambrosch, P; Csiszar, K

2007-05-01

196

Missense mutations in cytochrome c maturation genes provide new insights into Rhodobacter capsulatus cbb3-type cytochrome c oxidase biogenesis.  

PubMed

The Rhodobacter capsulatus cbb(3)-type cytochrome c oxidase (cbb(3)-Cox) belongs to the heme-copper oxidase superfamily, and its subunits are encoded by the ccoNOQP operon. Biosynthesis of this enzyme is complex and needs dedicated biogenesis genes (ccoGHIS). It also relies on the c-type cytochrome maturation (Ccm) process, which requires the ccmABCDEFGHI genes, because two of the cbb(3)-Cox subunits (CcoO and CcoP) are c-type cytochromes. Recently, we reported that mutants lacking CcoA, a major facilitator superfamily type transporter, produce very small amounts of cbb(3)-Cox unless the growth medium is supplemented with copper. In this work, we isolated "Cu-unresponsive" derivatives of a ccoA deletion strain that exhibited no cbb(3)-Cox activity even upon Cu supplementation. Molecular characterization of these mutants revealed missense mutations in the ccmA or ccmF gene, required for the Ccm process. As expected, Cu-unresponsive mutants lacked the CcoO and CcoP subunits due to Ccm defects, but remarkably, they contained the CcoN subunit of cbb(3)-Cox. Subsequent construction and examination of single ccm knockout mutants demonstrated that membrane insertion and stability of CcoN occurred in the absence of the Ccm process. Moreover, while the ccm knockout mutants were completely incompetent for photosynthesis, the Cu-unresponsive mutants grew photosynthetically at lower rates and produced smaller amounts of cytochromes c(1) and c(2) than did a wild-type strain due to their restricted Ccm capabilities. These findings demonstrate that different levels of Ccm efficiency are required for the production of various c-type cytochromes and reveal for the first time that maturation of the heme-Cu-containing subunit CcoN of R. capsulatus cbb(3)-Cox proceeds independently of that of the c-type cytochromes during the biogenesis of this enzyme. PMID:23123911

Ekici, Seda; Jiang, Xinpei; Koch, Hans-Georg; Daldal, Fevzi

2012-11-02

197

Features and applications of bilirubin oxidases.  

PubMed

Discovered in 1981 by Tanaka and Murao (Agric Biol Chem 45:2383-2384, 1981), bilirubin oxidase (BOD) is a sub-group of multicopper oxidases (MCOs) also utilizing four Cu(+/2+) ions. It catalyzes the oxidation of bilirubin to biliverdin, hence the classification of bilirubin oxidase, and has been primarily used in the determination of bilirubin in serum and thereby in the diagnostic of jaundice. Unlike laccases, the most studied MCOs, BODs display a high activity and stability at neutral pH, a high tolerance towards chloride anions and other chelators, and for some species, a high thermal tolerance. Therefore, BODs could potentially be an alternative to laccase which are so far mainly restricted to applications in acid media. Because of growing interest in BODs for numerous applications under mild pH conditions, based on the number of patents and publications published in the last 5 years, here I will summarize the available data on the biochemical properties of BODs, their occurrence, and their possible biotechnological use in (1) the field of Healthcare for the elaboration of biofuel cells or bilirubin sensors or (2) the field of environmentally desirable applications such as depollution, decolorization of dyes, and pulp bleaching. PMID:22878843

Mano, Nicolas

2012-08-03

198

Nuclear functions required for cytochrome c oxidase biogenesis in Saccharomyces cerevisiae: multiple trans-acting nuclear genes exert specific effects on expression of each of the cytochrome c oxidase subunits encoded on mitochondrial DNA.  

PubMed

Fourteen nuclear complementation groups of mutants that specifically affect the three mitochondrially-encoded subunits of yeast cytochrome c oxidase have been characterized. Genes represented by these complementation groups are not required for mitochondrial transcription, transcript processing, or translation per se but are required for the expression of one of the three genes--COX1, COX2, or COX3--which encode the cytochrome c oxicase subunits I, II, or III, respectively. Five of these genes affect the biogenesis of cytochrome c oxidase subunit I, 3 affect the biogenesis of subunit II, 3 affect the biogenesis of subunit III and 3 affect the biogenesis of both cytochrome c oxidase subunit I and cytochrome b, the product of COB. Among the 5 complementation groups of mutants that affect the expression of COX1, 2 lack COX1 transcripts, 1 produces incompletely processed COX1 transcripts, and 2 contain normal levels of normal-sized COX1 transcripts. In contrast, all 3 complementation groups which affect the expression of COX2 and all 3 complementation groups which affect the expression of COX3 exhibit no, or little, detectable difference with respect to the wild type pattern of transcripts. The 3 complementation groups which affect the expression of both COX1 and COB all have aberrant COX1 and COB transcript patterns. These findings indicate that multiple trans-acting nuclear genes are required for specific expression of each COX gene encoded on mitochondrial DNA and suggest that their products act at different steps in the expression of these mitochondrial genes. PMID:2833360

Kloeckener-Gruissem, B; McEwen, J E; Poyton, R O

1987-01-01

199

THE ISOAMYL OXIDASE GENE IN PENICILLIUM GRISEOFULVUM IS PART OF THE PATULIN BIOSYNTHETIC PATHWAY  

Technology Transfer Automated Retrieval System (TEKTRAN)

Genes for the patulin biosynthetic pathway are likely to be arranged in a cluster, as is the case for other mycotoxins. GeneWalking was performed to identify genes both upstream and downstream of the isoepoxydon dehydrogenase (idh) gene in Penicillium griseofulvum NRRL 2159A. A gene with high sequ...

200

Genetic diversity of the Asian shore crab, Hemigrapsus sanguineus, in Korea and Japan inferred from mitochondrial cytochrome c oxidase subunit I gene  

Microsoft Academic Search

The genetic diversity and population history of the Asian shore crab, Hemigrapsus sanguineus, were investigated with a nucleotide sequence analysis of 536 base pairs (bp) of the mitochondrial cytochrome c oxidase subunit I gene (COI) in 111 samples collected from four populations in Korea and one in Japan. In total, 28 haplotypes were defined by 27 variable nucleotide sites in

Moongeun Yoon; Sung-Eic Hong; Yoon Kwon Nam; Dong Soo Kim

2011-01-01

201

Increase in Anthraquinone Content in Rubia cordifolia Cells Transformed by rol Genes Does Not Involve Activation of the NADPH Oxidase Signaling Pathway  

Microsoft Academic Search

It has been reported that rol plant oncogenes located in Ri-plasmids of Agrobacterium rhizogenes activated synthesis of secondary metabolites in the transformed plant cells. The activator mechanism is still unknown. In this work, we studied whether the NADPH oxidase-signaling pathway, which regulates the synthesis of defense metabolites in plants, is involved in the activator function of the rol genes. It

V. P. Bulgakov; G. K. Tchernoded; N. P. Mischenko; Yu. N. Shkryl; V. P. Glazunov; S. A. Fedoreyev; Yu. N. Zhuravlev

2003-01-01

202

Role of a Newly Cloned Alternative Oxidase Gene ( BjAOX1a ) in Turnip Mosaic Virus (TuMV) Resistance in Mustard  

Microsoft Academic Search

A new alternative oxidase (AOX) gene, designated as BjAOX1a, of mustard (Brassica juncea) was cloned by reverse transcription-polymerase chain reaction (RT-PCR). The full-length cDNA of BjAOX1a was 1,346 bp in size and containing an open reading frame (ORF) of 1,083 bp in size. The predicted amino acid sequence exhibited\\u000a 82.17% homology to the alternative oxidase of Arabidopsis thaliana. Analysis of functional regions

Lei Zhu; Yanman Li; Neelam Ara; Jinghua Yang; Mingfang Zhang

203

Radioprotective effects of Bmi-1 involve epigenetic silencing of oxidase genes and enhanced DNA repair in normal human keratinocytes.  

PubMed

Normal human keratinocytes (NHKs) undergo premature senescence following exposure to ionizing radiation (IR). This study investigates the effect of Bmi-1, a polycomb group protein, on radiation-induced senescence response. When exposed to IR, NHK transduced with Bmi-1 (NHK/Bmi-1) showed reduced senescent phenotype and enhanced proliferation compared with control cells (NHK/B0). To investigate the underlying mechanism, we determined the production of reactive oxygen species (ROS), expression of ROS-generating enzymes, and DNA repair activities in cells. ROS level was increased upon irradiation but notably reduced by Bmi-1 transduction. Irradiation led to strong induction of oxidase genes, e.g., Lpo (lactoperoxidase), p22-phox, p47-phox, and Gp91, in NHK/B0 but their expression was almost completely silenced in NHK/Bmi-1. Induction of oxidase genes upon irradiation was linked with loss of trimethylated histone 3 at lysine 27 (H3K27Me3), but NHK/Bmi-1 expressed a higher level of H3K27Me3 compared with NHK/B0. Bmi-1 transduction suppressed IR-associated induction of jumanji domain containing 3 while enhancing the expression of EZH2, thereby preventing the loss of H3K27Me3 in the irradiated cells. Furthermore, NHK/Bmi-1 demonstrated increased repair of IR-induced DNA damage compared with NHK/B0. These results indicate that Bmi-1 elicits radioprotective effects on NHK by mitigating the genotoxicity of IR through epigenetic mechanisms. PMID:21307872

Dong, Qinghua; Oh, Ju-Eun; Chen, Wei; Kim, Roy; Kim, Reuben H; Shin, Ki-Hyuk; McBride, William H; Park, No-Hee; Kang, Mo K

2011-02-10

204

Effects of hydrogen sulfide on alternative pathway respiration and induction of alternative oxidase gene expression in rice suspension cells.  

PubMed

The toxic effects of H2S on plants are well documented. However, the molecular mechanisms reponsible for inhibition of plants by H2S are still not completely understood. We determined the effects of NaHS in the range of 0.5-10 mM on the growth of rice suspension culture cells, as well as on the expression of the alternative oxidase (AOX) gene. AOX is the terminal oxidase of the alternative pathway (AP) and exists in plant mitochondria. The results showed that H2S treatment enhanced the AP activity. During the process of H2S treatment for 4 h, the AP activity increased dramatically and achieved the peak value at a concentration of 2 mM NaHS. Then it declined at higher concentrations of NaHS (5-10 mM) and maintained a steady level. The AOX1 gene transcript level also showed a similar change as the AP activity. Interestingly, different NaHS concentrations seemed to have different effects on the expression of AOX1a, AOX1b, and AOX1c. The induction of AOX expression by low concentrations of NaHS was inferred through a reactive oxygen species (ROS)-independent pathway. At the same time, rice cells grown in culture were very sensitive to H2S, different H2S concentrations induced an increase in the cell viability. These results indicate that the H2S-induced AOX induction might play a role in inhibiting the ROS production and have an influence on cell viability. PMID:20737915

Xiao, Man; Ma, Jun; Li, Hongyu; Jin, Han; Feng, Hanqing

205

The aldehyde oxidase gene cluster in mice and rats. Aldehyde oxidase homologue 3, a novel member of the molybdo-flavoenzyme family with selective expression in the olfactory mucosa.  

PubMed

Mammalian molybdo-flavoenzymes are oxidases requiring FAD and molybdopterin (molybdenum cofactor) for their catalytic activity. This family of proteins was thought to consist of four members, xanthine oxidoreductase, aldehyde oxidase 1 (AOX1), and the aldehyde oxidase homologues 1 and 2 (AOH1 and AOH2, respectively). Whereas the first two enzymes are present in humans and various other mammalian species, the last two proteins have been described only in mice. Here, we report on the identification, in both mice and rats, of a novel molybdo-flavoenzyme, AOH3. In addition, we have cloned the cDNAs coding for rat AOH1 and AOH2, demonstrating that this animal species has the same complement of molybdo-flavoproteins as the mouse. The AOH3 cDNA is characterized by remarkable similarity to AOX1, AOH1, AOH2, and xanthine oxidoreductase cDNAs. Mouse AOH3 is selectively expressed in Bowman's glands of the olfactory mucosa, although small amounts of the corresponding mRNA are present also in the skin. In the former location, two alternatively spliced forms of the AOH3 transcript with different 3'-untranslated regions were identified. The general properties of AOH3 were determined by purification of mouse AOH3 from the olfactory mucosa. The enzyme possesses aldehyde oxidase activity and oxidizes, albeit with low efficiency, exogenous substrates that are recognized by AOH1 and AOX1. The Aoh3 gene maps to mouse chromosome 1 band c1 and rat chromosome 7 in close proximity to the Aox1, Aoh1, and Aoh2 loci and has an exon/intron structure almost identical to that of the other molybdo-flavoenzyme genes in the two species. PMID:15383531

Kurosaki, Mami; Terao, Mineko; Barzago, Maria Monica; Bastone, Antonio; Bernardinello, Davide; Salmona, Mario; Garattini, Enrico

2004-09-20

206

Over-expression of a gibberellin 2-oxidase gene from Phaseolus coccineus L. enhances gibberellin inactivation and induces dwarfism in Solanum species  

Microsoft Academic Search

Gibberellins (GAs) are endogenous hormones that play a predominant role in regulating plant stature by increasing cell division\\u000a and elongation in stem internodes. The product of the GA 2-oxidase gene from Phaseolus coccineus (PcGA2ox1) inactivates C19-GAs, including the bioactive GAs GA1 and GA4, by 2?-hydroxylation, reducing the availability of these GAs in plants. The PcGA2ox1 gene was introduced into Solanum

C. Dijkstra; E. Adams; A. Bhattacharya; A. F. Page; P. Anthony; S. Kourmpetli; J. B. Power; K. C. Lowe; S. G. Thomas; P. Hedden; A. L. Phillips; M. R. Davey

2008-01-01

207

The leader intron of Arabidopsis thaliana genes encoding cytochrome c oxidase subunit 5c promotes high-level expression by increasing transcript abundance and translation efficiency  

Microsoft Academic Search

The involvement of regions located upstream of the translation start site in the expression of two Arabidopsis thaliana nuclear COX5c genes encoding subunit 5c of mitochondrial cytochrome c oxidase has been analysed. It was observed that these regions, which include a leader intron, direct the tissue-specific expression of the gus reporter gene, mainly in root and shoot meristems, actively growing

Graciela C. Curi; Raquel L. Chan; Daniel H. Gonzalez

2005-01-01

208

Molecular, phylogenetic and comparative genomic analysis of the cytokinin oxidase/dehydrogenase gene family in the Poaceae.  

PubMed

The genomes of cereals such as wheat (Triticum aestivum) and barley (Hordeum vulgare) are large and therefore problematic for the map-based cloning of agronomicaly important traits. However, comparative approaches within the Poaceae permit transfer of molecular knowledge between species, despite their divergence from a common ancestor sixty million years ago. The finding that null variants of the rice gene cytokinin oxidase/dehydrogenase 2 (OsCKX2) result in large yield increases provides an opportunity to explore whether similar gains could be achieved in other Poaceae members. Here, phylogenetic, molecular and comparative analyses of CKX families in the sequenced grass species rice, brachypodium, sorghum, maize and foxtail millet, as well as members identified from the transcriptomes/genomes of wheat and barley, are presented. Phylogenetic analyses define four Poaceae CKX clades. Comparative analyses showed that CKX phylogenetic groupings can largely be explained by a combination of local gene duplication, and the whole-genome duplication event that predates their speciation. Full-length OsCKX2 homologues in barley (HvCKX2.1, HvCKX2.2) and wheat (TaCKX2.3, TaCKX2.4, TaCKX2.5) are characterized, with comparative analysis at the DNA, protein and genetic/physical map levels suggesting that true CKX2 orthologs have been identified. Furthermore, our analysis shows CKX2 genes in barley and wheat have undergone a Triticeae-specific gene-duplication event. Finally, by identifying ten of the eleven CKX genes predicted to be present in barley by comparative analyses, we show that next-generation sequencing approaches can efficiently determine the gene space of large-genome crops. Together, this work provides the foundation for future functional investigation of CKX family members within the Poaceae. PMID:21838715

Mameaux, Sabine; Cockram, James; Thiel, Thomas; Steuernagel, Burkhard; Stein, Nils; Taudien, Stefan; Jack, Peter; Werner, Peter; Gray, John C; Greenland, Andy J; Powell, Wayne

2011-08-15

209

Sphingosylphosphorylcholine down-regulates filaggrin gene transcription through NOX5-based NADPH oxidase and cyclooxygenase-2 in human keratinocytes.  

PubMed

Sphingosylphosphorylcholine (SPC) mediates various inflammatory and behavioral responses in atopic dermatitis. Recent studies have shown that dysfunction of the epidermal permeability barrier itself plays a primary role in the etiology of atopic dermatitis. However, the effects of SPC on major proteins essential to the development of the epidermal permeability barrier such as filaggrin, loricrin, involucrin, keratin 1, keratin 10 and small proline-rich proteins are still unclear. In this study, we demonstrated that SPC significantly reduces filaggrin gene transcription, implying that SPC plays a pivotal role in impairment of the epidermal permeability barrier in atopic dermatitis lesional skin. In cultured normal human keratinocytes (NHKs), SPC increases the intracellular level of reactive oxygen species (ROS) and up-regulates NADPH oxidase 5 (NOX5) gene transcription. SPC also stimulates prostaglandin (PG) E(2) production by increasing cyclooxygenase (COX)-2 expression in NHK. The effects of the prostanoid EP receptor agonists, limaprost, butaprost, and sulprostone on filaggrin gene expression in NHK suggest that the prostanoid EP2 receptor plays a significant role in the PGE(2)-mediated filaggrin down-regulation. In contrast, limaprost and butaprost do not affect NOX5 expression in NHK, implying that the NOX5-regulated ROS pathway stimulated by SPC may be upstream of the COX-2 pathway. We propose that the increase in SPC levels further aggravates dermatological symptoms of atopic dermatitis through SPC-induced down-regulation of filaggrin in NHK. PMID:20230798

Choi, Hyun; Kim, Shinhyoung; Kim, Hyoung-June; Kim, Kwang-Mi; Lee, Chang-Hoon; Shin, Jennifer H; Noh, Minsoo

2010-03-15

210

The genetic basis of "Scarsdale Gourmet Diet" variegate porphyria: a missense mutation in the protoporphyrinogen oxidase gene.  

PubMed

The porphyrias are disorders of porphyrin or porphyrin-precursor metabolism that result from inherited or acquired aberrations in the control of the porphyrin-heme biosynthetic pathway. Variegate porphyria (VP), one of the acute hepatic porphyrias, is characterized by a partial reduction in the activity of protoporphyrinogen oxidase (PPO), and recently, mutations in the PPO gene on chromosome 1q22-23 have been described. Our purpose was to identify the underlying genetic lesion in a severely affected patient with VP and to detect the silent mutation carriers in her family. The disease in this patient was precipitated by carbohydrate restriction as outlined in the "Scarsdale Gourmet Diet". Our mutation detection and confirmation strategy included PCR, automated sequencing, and restriction enzyme digestion. We identified a missense mutation in the patient and five family members. The mutation consisted of a previously unreported C-to-T transition in exon 5 of the PPO gene, resulting in the substitution of arginine by cysteine, designated R152C. This arginine residue is evolutionarily highly conserved in humans, mice, bacteria, yeast, and plants, indicating the importance of this residue in PPO. Our study established that a missense mutation in the PPO gene was the underlying mutation in this patient with VP and explained the occurrence of the phenotype in this family. PMID:9763307

Frank, J; Poh-Fitzpatrick, M B; King, L E; Christiano, A M

1998-08-01

211

A Laterally Acquired Galactose Oxidase-Like Gene Is Required for Aerial Development during Osmotic Stress in Streptomyces coelicolor  

PubMed Central

Phylogenetic reconstruction revealed that most Actinobacterial orthologs of S. coelicolor SCO2837, encoding a metal-dependent galactose oxidase-like protein, are found within Streptomyces and were probably acquired by horizontal gene transfer from fungi. Disruption of SCO2837 (glxA) caused a conditional bld phenotype that could not be reversed by extracellular complementation. Studies aimed at characterising the regulation of expression of glxA showed that it is not a target for other bld genes. We provide evidence that glxA is required for osmotic adaptation, although independently from the known osmotic stress response element SigB. glxA has been predicted to be part of an operon with the transcription unit comprising the upstream cslA gene and glxA. However, both phenotypic and expression studies indicate that it is also expressed from an independent promoter region internal to cslA. GlxA displays an in situ localisation pattern similar to that one observed for CslA at hyphal tips, but localisation of the former is independent of the latter. The functional role of GlxA in relation to CslA is discussed.

Liman, Recep; Facey, Paul D.; van Keulen, Geertje; Dyson, Paul J.; Del Sol, Ricardo

2013-01-01

212

High-resolution melting analysis of 15 genes in 60 patients with cytochrome-c oxidase deficiency.  

PubMed

Cytochrome-c oxidase (COX) deficiency is one of the common childhood mitochondrial disorders. Mutations in genes for the assembly factors SURF1 and SCO2 are prevalent in children with COX deficiency in the Slavonic population. Molecular diagnosis is difficult because of the number of genes involved in COX biogenesis and assembly. The aim of this study was to screen for mutations in 15 nuclear genes that encode the 10 structural subunits, their isoforms and two assembly factors of COX in 60 unrelated Czech children with COX deficiency. Nine novel variants were identified in exons and adjacent intronic regions of COX4I2, COX6A1, COX6A2, COX7A1, COX7A2 and COX10 using high-resolution melting (HRM) analysis. Online bioinformatics servers were used to predict the importance of the newly identified amino-acid substitutions. The newly characterized variants updated the contemporary spectrum of known genetic sequence variations that are present in the Czech population, which will be important for further targeted mutation screening in Czech COX-deficient children. HRM and predictive bioinformatics methodologies are advantageous because they are low-cost screening tools that complement large-scale genomic studies and reduce the required time and effort. PMID:22592081

Vondrackova, Alzbeta; Vesela, Katerina; Hansikova, Hana; Docekalova, Dagmar Zajicova; Rozsypalova, Eva; Zeman, Jiri; Tesarova, Marketa

2012-05-17

213

Genetic and in silico comparative mapping of the polyphenol oxidase gene in bread wheat (Triticum aestivum L.).  

PubMed

Polyphenol oxidases (PPOs) are involved in the time-dependent darkening and discolouration of Asian noodles and other wheat end products. In this study, a doubled haploid (DH) population derived from Chara (moderately high PPO activity)/WW2449 (low PPO activity) was screened for PPO activity based on L-DOPA and L-tyrosine assays using whole seeds. Both these assays were significantly genetically correlated (r = 0.91) in measuring the PPO activity in this DH population. Quantitative trait loci (QTLs) analysis utilising a skeleton map enabled us to identify a major QTL controlling PPO activity based on L-DOPA and L-tyrosine on the long arm of chromosome 2A. The simple sequence repeat (SSR) marker GWM294b explained over 82% of the line mean phenotypic variation from samples collected in both 2000 and 2003. Four SSR markers were validated for PPO linkage in genetically diverse backgrounds and proven to correctly predict the PPO activity in more than 92% of wheat lines. Physical mapping using deletion lines of Chinese Spring has confirmed the location of the GWM294b, GWM312 and WMC170 on chromosome 2AL, between deletion breakpoints 2AL-C to 0.85. In order to identify functional gene markers, data searches for alignments between rice BAC/PAC clones assembled on chromosome 1 and 4, chromosome 7, and (1) the wheat expressed sequence tags mapped in deletion bin (2AL-C to 0.85) and (2) the coding sequence of a previously cloned wheat PPO gene were made and found significant sequence similarities with the PPO gene or common central domain of tyrosinase. Available PPO gene sequences in the National Centre for Biotechnology Information (NCBI) database have revealed that there is a significant molecular diversity at the nucleotide and amino acid level in the wheat PPO genes. PMID:15918034

Raman, Rosy; Raman, Harsh; Johnstone, Katie; Lisle, Chris; Smith, Alison; Martin, Peter; Matin, Peter; Allen, Helen

2005-05-26

214

Gremlin utilizes canonical and non-canonical TGF? signaling to induce lysyl oxidase (LOX) genes in human trabecular meshwork cells.  

PubMed

The TGF?/BMP signaling pathways are involved in glaucomatous damage to the trabecular meshwork (TM) leading to elevated intraocular pressure (IOP), which is a major risk factor for the development and progression of glaucoma. The BMP antagonist gremlin is elevated in glaucomatous TM cells and tissues and can directly elevate IOP. Gremlin utilizes the TGF?2/SMAD pathway to induce TM extracellular matrix (ECM) proteins. The purpose of this study is to determine whether expression of the ECM cross-linking lysyl oxidase (LOX) genes is regulated by gremlin in cultured human TM cells. Human TM cells were treated with recombinant gremlin, and expression of the LOX genes was examined by quantitative RT-PCR and western immunoblotting. TM cells were pretreated with TGFBR inhibitors (LY364947 or SB431542), an inhibitor of the SMAD signaling pathway (SIS3), or with JNK (SP600125) and p38 MAPK (SB203580) inhibitors to identify the signaling pathway(s) involved in gremlin induction of LOX protein expression. All five LOX genes (LOX and LOXL1-4) were induced by gremlin. Gremlin induction of LOX genes and protein expression was blocked by TGFBR inhibitors as well as by inhibitors of the SMAD3, JNK and p38 MAPK signaling pathways. We conclude that gremlin employs both canonical TGF?/SMAD and the non-canonical JNK and p38 MAPK signaling pathways to induce LOX genes and proteins in cultured human TM cells. Increased LOX levels may be at least partially responsible for gremlin-mediated IOP elevation and increased aqueous humor outflow resistance leading to glaucoma. PMID:23748100

Sethi, Anirudh; Wordinger, Robert J; Clark, Abbot F

2013-06-05

215

ACC oxidase genes expressed in the wood-forming tissues of loblolly pine (Pinus taeda L.) include a pair of nearly identical paralogs (NIPs).  

PubMed

1-Aminocyclopropane-1-carboxylate (ACC) oxidase catalyzes the final reaction of the ethylene biosynthetic pathway, converting the unusual cyclic amino acid, ACC, into ethylene. Past studies have shown a possible link between ethylene and compression wood formation in conifers, but the relationship has received no more than modest study at the gene expression level. In this study, a cDNA clone encoding a putative ACC oxidase, PtACO1, was isolated from a cDNA library produced using mRNA from lignifying xylem of loblolly pine (Pinus taeda) trunk wood. The cDNA clone comprised an open reading frame of 1461 bp encoding a protein of 333 amino acids. Using PCR amplification techniques, a genomic clone corresponding to PtACO1 was isolated and shown to contain three introns with typical GT/AG boundaries defining the splice junctions. The PtACO1 gene product shared 70% identity with an ACC oxidase from European white birch (Betula pendula), and phylogenetic analyses clearly placed the gene product in the ACC oxidase cluster of the Arabidopsis thaliana 2-oxoglutarate-dependent dioxygenase superfamily tree. The PtACO1 sequence was used to identify additional ACC oxidase clones from loblolly pine root cDNA libraries characterized as part of an expressed sequence tag (EST) discovery project. The PtACO1 sequence was also used to recover additional paralogous sequences from genomic DNA, one of which (PtACO2) turned out to be >98% identical to PtACO1 in the nucleotide coding sequence, leading to its classification as a "nearly identical paralog" (NIP). Quantitative PCR analyses showed that the expression level of PtACO1-like transcripts varied in different tissues, as well as in response to hormonal treatments and bending. Possible roles for PtACO1 in compression wood formation in loblolly pine and the discovery of its NIP are discussed in light of these results. PMID:20053371

Yuan, S; Wang, Y; Dean, J F D

2010-01-04

216

The NADPH Oxidase Subunit NOX4 Is a New Target Gene of the Hypoxia-inducible Factor-1  

PubMed Central

NADPH oxidases are important sources of reactive oxygen species (ROS), possibly contributing to various disorders associated with enhanced proliferation. NOX4 appears to be involved in vascular signaling and may contribute to the response to hypoxia. However, the exact mechanisms controlling NOX4 levels under hypoxia are not resolved. We found that hypoxia rapidly enhanced NOX4 mRNA and protein levels in pulmonary artery smooth-muscle cells (PASMCs) as well as in pulmonary vessels from mice exposed to hypoxia. This response was dependent on the hypoxia-inducible transcription factor HIF-1? because overexpression of HIF-1? increased NOX4 expression, whereas HIF-1? depletion prevented this response. Mutation of a putative hypoxia-responsive element in the NOX4 promoter abolished hypoxic and HIF-1?–induced activation of the NOX4 promoter. Chromatin immunoprecipitation confirmed HIF-1? binding to the NOX4 gene. Induction of NOX4 by HIF-1? contributed to maintain ROS levels after hypoxia and hypoxia-induced proliferation of PASMCs. These findings show that NOX4 is a new target gene of HIF-1? involved in the response to hypoxia. Together with our previous findings that NOX4 mediates HIF-1? induction under normoxia, these data suggest an important role of the signaling axis between NOX4 and HIF-1? in various cardiovascular disorders under hypoxic and also nonhypoxic conditions.

Diebold, Isabel; Petry, Andreas; Hess, John

2010-01-01

217

Characterization of Fasciola hepatica genotypes from cattle and sheep in Iran using cytochrome C oxidase gene (CO1).  

PubMed

The present study compared the genetic variation among 19 different isolates of Fasciola hepatica from cattle and sheep in different areas of Iran using sequence data for mitochondrial DNA gene, the subunit 1 of cytochrome C oxidase gene (CO1). Four different CO1 genotypes were detected among F. hepatica isolates that showed five variable nucleotide positions (accession nos.; GQ398051, GQ398052, GQ398053, GQ398054). Nucleotide sequence variation among 19 isolates for CO1 analyzed in this study ranged from 0% to 0.98% in Iran. Among the five polymorphism sites identified in this study, only one (T to G at position 51 in 5'end of GQ175362) resulted in putative amino acid alteration of phenylalanine (TTT) to leucine (TTG) in CO1. A phylogenetic analysis of the sequence data revealed that host associations and geographic location are likely not useful markers for Fasciola genotype classification. In addition, morphological analysis showed that the ratios of body length and body width of some (n?=?5) of the 19 examined F. hepatica isolates were intermediate between F. hepatica and Fasciola gigantica, representing the substantial polymorphism of the F. hepatica species and the difficulty in the accurate recognition based on morphological features. In conclusion, Iranian F. hepatica exhibited the presence of considerable genetic diversity at CO1. PMID:22186976

Moazeni, Mohammad; Sharifiyazdi, Hassan; Izadpanah, Afshin

2011-12-21

218

Population genetic structure of the melon fly, Bactrocera cucurbitae (Coquillett) (Diptera: Tephritidae) based on mitochondrial cytochrome oxidase (COI) gene sequences.  

PubMed

Population genetic structure of melon fly analysed with mitochondrial cytochrome oxidase I gene suggested that melon fly populations across the globe is homogeneous with non-significant variation of 0.000-0.003 base substitutions per site. Test isolates representing various geographic situations across the world were placed in 26 mitochondrial haplotypes based on variations associated with a maximum of three mutational steps and the predominant haplotype i.e. H1 was present in all melon fly populations except Hawaiian population. Evolution of mtCOI gene suggested that the fly could have originated some 0.4 million years ago. The present study also indicated that the B. cucurbitae population expansion is an event of post Pleistocene warm climatic conditions with small number of founder population. The invasion of B. cucurbitae in Hawaii was associated with the large population size and the global presence of the fly is associated with human mediated dispersal. The very low genetic variation suggested that the fly management might be possible by large scale sterile insect techniques programme. PMID:22660946

Prabhakar, Chandra S; Mehta, Pawan K; Sood, Pankaj; Singh, Sunil K; Sharma, Prachi; Sharma, Prem N

2012-06-02

219

[Association between the canine monoamine oxidase B (MAOB) gene polymorphisms and behavior of puppies in open-field test].  

PubMed

Excitability, activity and exploration behavior of puppies in a novel open-field were tested in a total of 204 two-month-old German shepherd dog, labrador retriever or English springer spaniel puppies. The polymorphisms of monoamine oxidase B gene (MAOB) were detected by PCR-RFLP. Statistics analysis indicated that genotype and allele frequencies of the polymorphisms were significantly different among three breeds (P < 0.01). With GLM analysis of SAS software, association analysis was conducted between MAOB gene polymorphisms and locomotion and vocalization behavior parameters in the open-field test. The results showed that MAOB gene polymorphisms had a significant effect on walking time, squares crossed, lying time, the times of standing up against walls(P < 0.01 or P < 0.05) and were associated with the times of posture change (P=0.064). Walking time and squares crossed were higher in TT genotype puppies than those in TC and CC puppies (P < 0.05) and the times of posture change and standing up against walls were also higher than those in CC (P < 0.05). In addition, lying time in CC genotype puppies were higher than that in TT (P < 0.05). MAOB had a positive effect on walking time, lying time, squares crossed, the times of posture change, the times of standing up against walls in the three dog breeds that was highly statistically significant (P < 0.01 or P < 0.05). Our results imply that MAOB gene significantly affects the excitability, activity and exploration behavior of puppies in open-field test and TT genotype has favorable effects in these behavior traits. PMID:17098705

Li, Xiao-Hui; Xu, Han-Kun; Mao, Da-Gan; Ma, Da-Jun; Chen, Peng; Yang, Li-Guo

2006-11-01

220

Negative emotionality: monoamine oxidase B gene variants modulate personality traits in healthy humans  

PubMed Central

Monoamine oxidase A and B (MAOA and MAOB) appear to be involved in the pathogenesis of Major Depression, and vulnerability of Major Depression is associated with personality traits relating to positive and negative affect. This study aimed to investigate associations between MAOA and MAOB polymorphisms and personality traits of positive and negative emotionality in healthy volunteers, to elucidate mechanisms underlying personality and the risk for depression. Healthy Caucasian volunteers (N = 150) completed the Multiphasic Personality Questionnaire (MPQ), which includes independent superfactors of Positive Emotionality and Negative Emotionality. Participants were genotyped for 8 MAOA and 12 MAOB single nucleotide polymorphisms (SNPs). Association analyses for both SNPs and haplotypes were performed using the permutation approach implemented in PLINK. Negative Emotionality was significantly associated with the two highly linked MAOB polymorphisms rs10521432 and rs6651806 (p < 0.002). Findings were extended in haplotype analyses. For MAOB the 4-SNP haplotype GACG formed from rs1799836, rs10521432, rs6651806 and rs590551 was significantly related to lower Negative Emotionality scores (p < 0.002). MAOA was not related to personality in this study. Our finding provides the first evidence that MAOB polymorphisms influence levels of negative emotionality in healthy human volunteers. If confirmed, these results could lead to a better understanding of personality traits and inter-individual susceptibility developing psychiatric disorders such as major depression.

Dlugos, Andrea M.; Palmer, Abraham A.

2013-01-01

221

Association of lysyl oxidase-like 1 gene polymorphisms with exfoliation syndrome in Koreans  

PubMed Central

Purpose To evaluate the association of the lysyl oxidase-like 1 (LOXL1) single nucleotide polymorphisms (SNPs) in the Korean population with exfoliation syndrome (XFS) and to investigate the association between the SNPs and phenotypes of XFS. Methods Eighty-nine unrelated patients with XFS and 146 unrelated control subjects were recruited. LOXL1 SNPs, rs1048661, rs3825942, and rs2165241, were genotyped by direct DNA sequencing. Association between cases and controls was analyzed and phenotypic features of XFS were compared in terms of the SNPs. Results The three SNPs were found to be significantly associated with XFS. After adjusting for rs3825942, rs2165241, and other factors influencing the prevalence of XFS, only rs1048661 among three SNPs remained significant (95% confidence interval=4.11–35.78, p=6.11×10?6). T allele and TT genotype of rs1048661 and C allele and CC genotype of rs2165241 were associated with XFS, showing risk alleles and genotypes opposite to those reported in Caucasians. In the haplotype analysis, T-G-C was the only risk haplotype (p=3.35×10?12), which was not associated with XFS in Caucasians. No significant differences were noted in the allele and genotype frequencies depending on phenotypic features of XFS. Conclusions Three LOXL1 SNPs are associated with XFS in the Korean population. Risk alleles and genotypes of rs1048661 and rs2165241 in Korean have a similar pattern with those of East Asians, including Japanese and Northern Chinese, while they have a different pattern from those of Caucasians.

Sagong, Min; Gu, Byoung Young

2011-01-01

222

NADPH oxidase-derived reactive oxygen species increases expression of monocyte chemotactic factor genes in cultured adipocytes.  

PubMed

Excess glucose and free fatty acids delivered to adipose tissue causes local inflammation, which contributes to insulin resistance. Glucose and palmitate generate reactive oxygen species (ROS) in adipocytes, leading to monocyte chemotactic factor gene expression. Docosahexaenoate (DHA) has the opposite effect. In this study, we evaluated the potential sources of ROS in the presence of excess nutrients. Differentiated 3T3-L1 adipocytes were exposed to palmitate and DHA (250 ?M) in either 5 or 25 mM glucose to evaluate the relative roles of mitochondrial electron transport and NADPH oxidases (NOX) as sources of ROS. Excess glucose and palmitate did not increase mitochondrial oxidative phosphorylation. However, glucose exposure increased glycolysis. Of the NOX family members, only NOX4 was expressed in adipocytes. Moreover, its activity was increased by excess glucose and palmitate and decreased by DHA. Silencing NOX4 inhibited palmitate- and glucose-stimulated ROS generation and monocyte chemotactic factor gene expression. NADPH, a substrate for NOX, and pentose phosphate pathway activity increased with glucose but not palmitate and decreased with DHA exposure. Inhibition of the pentose phosphate pathway by glucose-6-phosphate dehydrogenase inhibitors and siRNA suppressed ROS generation and monocyte chemotactic factor gene expression induced by both glucose and palmitate. Finally, both high glucose and palmitate induced NOX4 translocation into lipid rafts, effects that were blocked by DHA. Excess glucose and palmitate generate ROS via NOX4 rather than by mitochondrial oxidation in cultured adipocytes. NOX4 is regulated by both NADPH generated in the PPP and translocation of NOX4 into lipid rafts, leading to expression of monocyte chemotactic factors. PMID:22287546

Han, Chang Yeop; Umemoto, Tomio; Omer, Mohamed; Den Hartigh, Laura J; Chiba, Tsuyoshi; LeBoeuf, Renee; Buller, Carolyn L; Sweet, Ian R; Pennathur, Subramaniam; Abel, E Dale; Chait, Alan

2012-01-27

223

NADPH Oxidase-derived Reactive Oxygen Species Increases Expression of Monocyte Chemotactic Factor Genes in Cultured Adipocytes*  

PubMed Central

Excess glucose and free fatty acids delivered to adipose tissue causes local inflammation, which contributes to insulin resistance. Glucose and palmitate generate reactive oxygen species (ROS) in adipocytes, leading to monocyte chemotactic factor gene expression. Docosahexaenoate (DHA) has the opposite effect. In this study, we evaluated the potential sources of ROS in the presence of excess nutrients. Differentiated 3T3-L1 adipocytes were exposed to palmitate and DHA (250 ?m) in either 5 or 25 mm glucose to evaluate the relative roles of mitochondrial electron transport and NADPH oxidases (NOX) as sources of ROS. Excess glucose and palmitate did not increase mitochondrial oxidative phosphorylation. However, glucose exposure increased glycolysis. Of the NOX family members, only NOX4 was expressed in adipocytes. Moreover, its activity was increased by excess glucose and palmitate and decreased by DHA. Silencing NOX4 inhibited palmitate- and glucose-stimulated ROS generation and monocyte chemotactic factor gene expression. NADPH, a substrate for NOX, and pentose phosphate pathway activity increased with glucose but not palmitate and decreased with DHA exposure. Inhibition of the pentose phosphate pathway by glucose-6-phosphate dehydrogenase inhibitors and siRNA suppressed ROS generation and monocyte chemotactic factor gene expression induced by both glucose and palmitate. Finally, both high glucose and palmitate induced NOX4 translocation into lipid rafts, effects that were blocked by DHA. Excess glucose and palmitate generate ROS via NOX4 rather than by mitochondrial oxidation in cultured adipocytes. NOX4 is regulated by both NADPH generated in the PPP and translocation of NOX4 into lipid rafts, leading to expression of monocyte chemotactic factors.

Han, Chang Yeop; Umemoto, Tomio; Omer, Mohamed; Den Hartigh, Laura J.; Chiba, Tsuyoshi; LeBoeuf, Renee; Buller, Carolyn L.; Sweet, Ian R.; Pennathur, Subramaniam; Abel, E. Dale; Chait, Alan

2012-01-01

224

The monoamine oxidase A (MAO-A) gene, family function and maltreatment as predictors of destructive behaviour during male adolescent alcohol consumption  

Microsoft Academic Search

Aim To investigate possible interactions between a polymorphism in the monoamine oxidase A (MAO-A) gene promoter, family relations and maltreatment\\/sexual abuse on adolescent alcohol-related problem behaviour among male adolescents. Design, setting and participants A cross-sectional study of a randomized sample of 66 male individuals from a total population of 16- and 19-year adolescents from a Swedish county. Boys, who volunteered

Kent W. Nilsson; Rickard L. Sjöberg; Hanna-Linn Wargelius; Jerzy Leppert; Leif Lindström; Lars Oreland

2007-01-01

225

Second-site, intragenic alterations in the gene encoding subunit II of cytochrome c oxidase from yeast can suppress two different missense mutations  

Microsoft Academic Search

Cytochrome c oxidase, a multi-subunit enzyme complex, accepts electrons from cytochrome c and transfers them to molecular oxygen to form water. Subunit II (Cox2p) of the enzyme complex provides the initial entry site for the electrons from cytochrome c. We report here the characterization of a yeast strain bearing a mutation in the gene encoding Cox2p which abolishes the activity

Quentin Machingo; Michael Mazourek; Vicki Cameron

2001-01-01

226

A Phylogenetic Analysis of Cuckoo Bumblebees ( Psithyrus, Lepeletier) and Bumblebees ( Bombus, Latreille) Inferred from Sequences of the Mitochondrial Gene Cytochrome Oxidase I  

Microsoft Academic Search

PCR amplification and direct sequencing of a 532-bp region of the mtCO-1(cytochrome oxidase I) gene from five true bumblebee species and six cuckoo bumblebee species were performed. The sequences were then aligned to the corresponding sequence in the honey bee. Phylogenetic analyses based on parsimony and maximum likelihood indicate that the cuckoo bumblebees form a monophyletic group within the true

Bo Vest Pedersen

1996-01-01

227

Truncating mutations in the Wilson disease gene ATP7B are associated with very low serum ceruloplasmin oxidase activity and an early onset of Wilson disease  

Microsoft Academic Search

BACKGROUND: Mutations in the gene ATP7B cause Wilson disease, a copper storage disorder with a high phenotypic and genetic heterogeneity. We aimed to evaluate whether 'severe' protein-truncating ATP7B mutations (SMs) are associated with low serum ceruloplasmin oxidase activities and an early age of onset when compared to missense mutations (MMs). METHODS: The clinical phenotype of 59 genetically confirmed WD patients

Uta Merle; Karl Heinz Weiss; Christoph Eisenbach; Sabine Tuma; Peter Ferenci; Wolfgang Stremmel

2010-01-01

228

Combination of polymorphic variants in serotonin transporter and monoamine oxidase-A genes may influence the risk for early-onset alcoholism.  

PubMed

The combinatory effect of polymorphisms in serotonin transporter and monoamine oxidase-A genes on the aetiopathogenesis of alcoholism was investigated in a sample of 714 individuals. Increased frequency of subjects having three 'suspected' genotypes (5-HTTLPR-LL, STin2-1010 and MAO-A 3-repeat allele) was found among type-2 alcoholic patients (P=0.0189). Results highlight serotonergic/genetic contribution to early-onset alcoholism. PMID:22627167

Bordukalo-Niksic, Tatjana; Stefulj, Jasminka; Matosic, Ana; Mokrovic, Gordana; Cicin-Sain, Lipa

2012-05-23

229

Constitutive expression of a fungal glucose oxidase gene in transgenic tobacco confers chilling tolerance through the activation of antioxidative defence system  

Microsoft Academic Search

Scientific evidences in the literature have shown that plants treated exogenously with micromole concentration of hydrogen\\u000a peroxide (H2O2) acquire abiotic stress tolerance potential, without substantial disturbances in the endogenous H2O2 pool. In this study, we enhanced the endogenous H2O2 content of tobacco (Nicotiana tabaccum L. cv. SR1) plants by the constitutive expression of a glucose oxidase (GO; EC 1.1.3.4) gene

Subbiyan Maruthasalam; Yi Lun Liu; Ching Mei Sun; Pei Ying Chen; Chih Wen Yu; Pei Fang Lee; Chin Ho Lin

2010-01-01

230

Association of A\\/G Polymorphism in Intron 13 of the Monoamine Oxidase B Gene with Schizophrenia in a Spanish Population  

Microsoft Academic Search

Background: Monoamine oxidase B (MAO-B) enzyme is involved in the oxidative metabolism of dopamine. We studied whether the A644G polymorphism in intron 13 of the MAO-B gene is a risk factor for schizophrenia. Methods: 242 subjects diagnosed with schizophrenia and related disorders and 290 hospital-based controls participated in the study. Genomic DNA was isolated from whole blood and genotyped with

Patricia Gassó; Miquel Bernardo; Sergi Mas; Anna Crescenti; Clemente Garcia; Eduard Parellada; Amalia Lafuente

2008-01-01

231

N-Ethylmaleimide-resistant acyl-coenzyme A oxidase from Arthrobacter ureafaciens NBRC 12140: Molecular cloning, gene expression and characterization of the recombinant enzyme  

Microsoft Academic Search

N-Ethylmaleimide (NEM)-resistant acyl-coenzyme A oxidase (ACO) has been desired for the determination of free fatty acids (FFAs). In order to meet this demand, we prepared recombinant ACO from Arthrobacter ureafaciens NBRC 12140. The coding region of the gene was 2109, encoding a protein of 703 amino acids with a predicted molecular mass of 76.5 kDa. The heterologous expression level in Escherichia

Mikio Bakke; Chiaki Setoyama; Retsu Miura; Naoki Kajiyama

2007-01-01

232

A novel human lysyl oxidase-like gene (LOXL4) on chromosome 10q24 has an altered scavenger receptor cysteine rich domain  

Microsoft Academic Search

We have identified a novel 14-exon human lysyl oxidase-like gene, LOXL4, on chromosome 10q24. The cDNA and derived amino acid sequence of LOXL4 demonstrates a conserved C-terminal region including the characteristic copper-binding site, lysyl and tyrosyl residues and a cytokine receptor-like domain. One of the four N-terminal SRCR domains contains a 13 amino acid insertion encoded by a short exon

L. Asuncion; B. Fogelgren; K. S. K. Fong; S. F. T. Fong; Y. Kim; K. Csiszar

2001-01-01

233

Phylogenetic relationships of Habronema microstoma and Habronema muscae (Spirurida: Habronematidae) within the order Spirurida inferred using mitochondrial cytochrome c oxidase subunit 1 ( cox1 ) gene analysis  

Microsoft Academic Search

The present study investigated genetic variability within a population of Habronema microstoma and Habronema muscae (Spirurida: Habronematidae) affecting horses in an endemic area of central Italy using polymerase chain reaction (PCR)-coupled\\u000a sequencing of the mitochondrial cytochrome c oxidase subunit 1 gene (cox1). No different cox1 sequences were detected in any of the H. muscae individual, while two haplotypes representing H.

Raffaella Iorio; Jan Šlapeta; Domenico Otranto; Barbara Paoletti; Annunziata Giangaspero; Donato Traversa

2009-01-01

234

Suppression of lysyl oxidase gene expression by methylation in pelvic organ prolapse  

Microsoft Academic Search

Introduction and hypothesis  We measured promoter methylation in the LOX gene in women with pelvic organ prolapse and in women without prolapse.\\u000a \\u000a \\u000a \\u000a Methods  Genomic DNA was isolated from the uterosacral ligaments of eight women with prolapse and eight women without prolapse as controls.\\u000a Genomic DNA was digested with BamHI and underwent sodium bisulfite modification. The LOX gene promoter region of ?246 to

John Klutke; Frank Z. Stanczyk; Qing Ji; Joseph David Campeau; Carl Georg Klutke

2010-01-01

235

ACC oxidase (ACO) genes in Trifolium occidentale (L.) and their relationship to ACO genes in white clover (T. repens L.) and T. pallescens (L.).  

PubMed

The identification and expression of two ACC oxidase (ACO) genes during leaf development in Trifolium occidentale (L.), one of the putative ancestral genomes of the allotetraploid, T. repens (L.; white clover), is described. In common with observations made in T. repens, the ACO genes displayed differential expression, with a TR-ACO2-like gene (designated TO-ACO2) confined to developing and early mature-green leaf tissue while expression of a TR-ACO3-like gene (designated TO-ACO3) is highest in leaves at the onset and during senescence. Biochemical analysis of TO-ACO2 revealed that both accumulation of the protein (determined by western analysis with a TR-ACO2 antibody) and enzyme activity matched the transcriptional activity of TO-ACO2. Western analysis also revealed that the Tr-ACO2 antibody recognised a protein of 37 kDa as a putative TP-ACO2 in T. pallescens. The 3'-UTRs of TO-ACO2 and TO-ACO3 were then compared with the 3'-UTRs of a TR-ACO2-like and TR-ACO3-like gene from T. pallescens, the other proposed ancestral genome (or closely related to the ancestor) of T. repens, with identity values of 87.8% for the ACO2-like genes and 94.8% for the ACO3-like genes. Comparison of the 3'-UTRs of TO-ACO2 with a TO-ACO2-like gene in T. repens (designated TR(O)-ACO2) and TP-ACO2 with a TP-ACO2-like gene in T. repens (designated TR(P)-ACO2) revealed identities of 100% and 96.6%, respectively, lending good support to T. occidentale as one of the ancestral genomes of T. repens. A similar comparison of the 3'-UTRs of TO-ACO3 with a TO-ACO3-like gene in T. repens (designated TR(O)-ACO3) and TP-ACO3 with a TP-ACO3-like gene in T. repens (designated TR(P)-ACO3) revealed identities of 99.5% and 97.9%, respectively, again supporting T. occidentale as one of the ancestral genomes. Further, these data confirm that both TO-ACO-like and TP-ACO-like genes are expressed in the allotetraploid T. repens. PMID:21320784

Du, Zhenning; Leung, Susanna; Dorling, Sarah J; McManus, Michael T

2011-01-21

236

Association of the -262C/T polymorphism in the catalase gene promoter and the C242T polymorphism of the NADPH oxidase P22phox gene with essential arterial hypertension in patients with diabetes mellitus type 2.  

PubMed

Abstract Aim: The aim of the present study was to test the association between genetic polymorphisms with functional effects on redox regulation: the -262C/T of the catalase gene promoter (rs1001179), the C242T of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase P22phox gene (rs4673), and the 594C/T polymorphism of the glutathione peroxidase gene (rs1050450) and arterial hypertension (AH) in patients with type 2 diabetes. Methods: 810 Slovenian subjects (Caucasians) with type 2 diabetes were enrolled in the cross-sectional study. Genotypes were determined by real-time PCR. Results: Univariate analysis failed to demonstrate an association between either the -262C/T of the catalase gene promoter (rs1001179) or the C242T polymorphism of the P22phox gene (rs4673) or the 594C/T polymorphism of the glutathione peroxidase gene (rs1050450) and AH. After adjustment for age, body mass index, fibrinogen level and high sensitivity C-reactive protein level, rs4673 was found to be an independent risk factor for AH in subjects with type 2 diabetes, whereas rs1001179 and rs1050450 were not. Conclusion: According to the results of cross-sectional study, the tested polymorphism of the NADPH oxidase P22phox gene (rs4673) was found to be associated with the development of AH, indicating that the oxidative stress gene NADPH oxidase might be implicated in the pathogenesis of AH in subjects with type 2 diabetes. PMID:23701472

Petrovi?, Daniel

2013-05-23

237

Nucleotide sequence of a segment of Drosophila mitochondrial DNA that contains the genes for cytochrome c oxidase subunits II and III and ATPase subunit 6.  

PubMed Central

The nucleotide sequence of a segment of the mtDNA molecule of Drosophila yakuba has been determined, within which have been identified the genes for tRNAleuUUR, cytochrome c oxidase subunit II (COII), tRNAlys, tRNAasp, URFA6L, ATPase subunit 6 (ATPase6), cytochrome c oxidase subunit III (COIII) and tRNAgly. The genes are arranged in the order given and all are transcribed from the same strand of the molecule in a direction opposite to that in which replication proceeds around the molecule. The tRNAlys gene is unusual among mitochondrial tRNAlys genes in that it contains a CTT anticodon. The triplet AGA is used to specify an amino acid in all of the COII, COIII, ATPase6, and URFA6L genes. However, the AGA codons found in these four polypeptide genes correspond in position to codons which specify nine different amino acids, but never arginine, in the equivalent polypeptide gene which have been sequenced from mtDNAs of mouse, yeast and Zea mays.

Clary, D O; Wolstenholme, D R

1983-01-01

238

Synergistic interaction between semicarbazide-sensitive amine oxidase and angiotensin-converting enzyme in diabetes: functional analysis by gene ontology.  

PubMed

Plasma semicarbazide-sensitive amine oxidase (SSAO) and angiotensin-converting enzyme (ACE) were studied for their correlation with diabetes (DM) complication. The effect of interaction between SSAO and ACE in DM complication is of interest. Studying the functional change due to interaction between SSAO and ACE is difficult. In this work, the author used a new gene ontology technology to predict the functional change resulting from the interaction between SSAO and ACE. According to this study, there is a synergetic effect resulting from the interaction between SSAP and ACE. This can imply that co-expression of SSAP-ACE leads to more severe complication of DM. However, the author can also demonstrate that some molecular functions such as proteasome activator activity of SSAO and hydrolase activity, metallopeptidase activity, and zinc ion binding of ACE are suppressed after co-expression. These results provide good information for further study in diabetes medicine. However, further experimental works are required to support this in silico research. PMID:18413170

Wiwanitkit, Viroj

2008-04-16

239

Genetic analysis of variegate porphyria (VP) in Italy: identification of six novel mutations in the protoporphyrinogen oxidase (PPOX) gene.  

PubMed

Variegate Porphyria (VP) is one of the acute hepatic porphyrias, and is clinically characterised by skin lesions and acute neuropsychiatric/visceral attacks that occur separately or together. The disorder is caused by a partial deficiency of protoporphyrinogen oxidase, the penultimate enzyme in the heme biosynthetic pathway, and a number of mutations have been described for the corresponding gene (PPOX). Here we report a genetic analysis of VP in Italy, and the identification of six novel and three previously characterised mutations from nine affected individuals and families. Among those newly identified, two mutations were small deletions (c.418_419delAA; c.759delA), leading to the formation of premature stop codons, two were splicing defects (IVS10+2T>G; IVS12+1G>C), one was a nonsense (c.384G>A=p.W128X) and one a missense mutation (c.848T>A=I283N). This is the first study of the molecular genetics of Variegate Porphyria in patients of Italian origin, and the finding of six novel mutations out of nine identified confirms the genetic heterogeneity observed for this disorder. PMID:12655566

D'Amato, Mauro; Bonuglia, Margherita; Barile, Simona; Griso, Daniela; Macri, Annelisa; Biolcati, Gianfranco

2003-04-01

240

Identification of a recurrent mutation in the protoporphyrinogen oxidase gene in Swiss patients with variegate porphyria: clinical and genetic implications.  

PubMed

Variegate porphyria (VP), one of the acute hepatic porphyrias, results from an autosomal dominantly inherited deficiency of protoporphyrinogen oxidase (PPOX), the seventh enzyme in heme biosynthesis. Affected individuals can develop both cutaneous symptoms and potentially life-threatening neurovisceral attacks. Thirty unrelated VP index patients and families are currently known in the Swiss Porphyrin Reference Laboratory in Zürich. In 16 of a total of 24 genetically tested families, we detected a recurrent mutation in the PPOX gene, designated 1082-1083insC, reflecting a prevalence of 67%. Haplotype analysis revealed that 1082-1083insC arose on a common genetic background and, thus, represents a novel founder mutation in the Swiss population. Knowledge on the carrier status within a family does not only allow for adequate genetic counseling but also for prevention of the potentially life-threatening acute porphyric attacks. Hence, future molecular screening in Swiss VP patients might be facilitated by first seeking for mutation 1082-1083insC. PMID:19656457

Van Tuyll Van Serooskerke, A M; Schneider-Yin, X; Schimmel, R J; Bladergroen, R S; Poblete-Gutiérrez, P; Barman, J; van Geel, M; Frank, J; Minder, E I

2009-07-01

241

Lack of association of Lysyl oxidase (LOX) gene polymorphisms with intracranial aneurysm in a south Indian population.  

PubMed

Intracranial aneurysm (IA) accounts for 85 % of haemorrhagic stroke and is mainly caused due to weakening of arterial wall. Lysyl oxidase (LOX) is a cuproenzyme involved in cross linking structural proteins collagen and elastin, thus providing structural stability to artery. Using a case-control study design, we tested the hypothesis whether the variants in LOX gene flanking the two LD block, can increase risk of aSAH among South Indian patients, either independently, or by interacting with other risk factors of the disease. SNPs were genotyped by fluorescence-based competitive allele-specific PCR (KASPar) chemistry. We selected 200 radiologically confirmed aneurysmal cases and 235 ethnically and age and gender matched controls from the Dravidian Malayalam speaking population of South India. We observed marked interethnic differences in the genotype distribution of LOX variants when compared to Japanese and African populations. However, there was no significant association with any of the LOX variants with IA. This study also could not observe any significant role of LOX polymorphisms in influencing IA either directly or indirectly through its confounding factors such as hypertension and gender in South Indian population. PMID:24065528

Sathyan, Sanish; Koshy, Linda; Sarada Lekshmi, K R; Easwer, H V; Premkumar, S; Alapatt, Jacob P; Nair, Suresh; Bhattacharya, R N; Banerjee, Moinak

2013-09-25

242

The choline oxidase gene codA confers salt tolerance to transgenic Eucalyptus globulus in a semi-confined condition.  

PubMed

The performance of tree species is influenced by environmental factors and growth stages. To evaluate the practical performance of transgenic tree species, it is insufficient to grow small, young trees under controlled conditions, such as in a growth chamber. Three transgenic Eucalyptus globulus lines, carrying the choline oxidase gene, were investigated for their salt tolerance and expression of the transgene at the young plantlet stage in a special netted-house. To clarify the characteristics at the young as well during the later stages, salt tolerance and the properties of the transgenic lines at large juvenile and adult stages were evaluated in the special netted-house. All transgenic lines showed high glycinebetaine content, particularly in young leaves. Trees of the transgenic line 107-1 showed low damage because of salinity stress based on the results from the chlorophyll analysis and malondialdehyde content, and they survived the high-salt-shock treatment at the large juvenile and adult stages. Only this line showed salt tolerance at all stages in the special netted-house. In this evaluation in the special netted-house, the tolerant line among young plantlets might perform better at all stages. Since evaluation in these special netted-house mimics field evaluation, line 107-1 is a potential tolerant line. PMID:22752644

Yu, Xiang; Kikuchi, Akira; Matsunaga, Etsuko; Morishita, Yoshihiko; Nanto, Kazuya; Sakurai, Nozomu; Suzuki, Hideyuki; Shibata, Daisuke; Shimada, Teruhisa; Watanabe, Kazuo N

2013-06-01

243

Lipid levels are associated with a regulatory polymorphism of the monoamine oxidase-A gene promoter (MAOA-uVNTR)  

PubMed Central

Summary Background The monoamine oxidase-A (MAOA) gene plays a vital role in the metabolism of neurotransmitters, e.g, serotonin, norepinephrine, and dopamine. A polymorphism in the promoter region (MAOA-uVNTR) affects transcriptional efficiency. Allelic variation in MAOA-uVNTR has been associated with body mass index (BMI). We extended previous work by examining relations among this polymorphism and serum lipid levels. Material/Methods The sample consisted of 74 males enrolled in a study of caregivers for relatives with dementia. Regression models, adjusted for age, race, group status (caregiver/control), and cholesterol lowering medication (yes/no), were used to examine associations between high verses low MAOA-uVNTR activity alleles and total cholesterol, HDL, LDL, VLDL, LDL/HDL ratio, triglycerides, and BMI. Results Higher total cholesterol (p<0.03), LDL/HDL ratio (p<0.01), triglycerides (p<0.02), and VLDL (p<0.02) were associated with low activity MAOA-uVNTR alleles. HDL and LDL were modestly related to MAOA-uVNTR activity, however, they did not reach the conventional significance level (p<0.07 and p<0.10, respectively). BMI (p<0.74) was unrelated to MAOA-uVNTR transcription. Conclusions The present findings suggest that MAOA-uVNTR may influence lipid levels and individuals with less active alleles are at increased health risk.

Brummett, Beverly H.; Boyle, Stephen H.; Siegler, Ilene C.; Zuchner, Stephan; Ashley-Koch, Allison; Williams, Redford B.

2009-01-01

244

Identification of forensically important flesh flies based on a shorter fragment of the cytochrome oxidase subunit I gene in China.  

PubMed

With the development of molecular identification, there has been a great deal of discussion about the feature of the mitochondrial DNA (mtDNA) fragments. Although longer fragments may minimize stochastic variation across taxa and be more likely to reflect broader patterns of nucleotide divergence, shorter fragments have many advantages, such as quick, easy and economical. Extensive application of long mtDNA segments for species identification cannot always be achieved as a result of constraints in time and money. In the present study, a molecular identification method involving the sequencing of a 272-bp 'barcode' fragment of the mitochondrial cytochrome oxidase subunit I (COI) gene from 55 specimens, representing 7 Chinese sarcophagid species from varying populations, was evaluated. Phylogenetic analysis of the sequenced segments showed that all sarcophagid specimens were properly assigned into seven species, which indicated the possibility of separation congeneric species with the short fragments. The results of this research will be instrumental for the implementation of the Chinese Sarcophagidae database. PMID:22150605

Guo, Y D; Cai, J F; Meng, F M; Chang, Y F; Gu, Y; Lan, L M; Liang, L; Wen, J F

2011-12-12

245

D-amino acid oxidase gene therapy sensitizes glioma cells to the antiglycolytic effect of 3-bromopyruvate.  

PubMed

Glioma tumors are refractory to conventional treatment. Glioblastoma multiforme is the most aggressive type of primary brain tumors in humans. In this study, we introduce oxidative stress-energy depletion (OSED) therapy as a new suggested treatment for glioblastoma. OSED utilizes D-amino acid oxidase (DAO), which is a promising therapeutic protein that induces oxidative stress and apoptosis through generating hydrogen peroxide (H2O2). OSED combines DAO with 3-bromopyruvate (3BP), a hexokinase II (HK II) inhibitor that interferes with Warburg effect, a metabolic alteration of most tumor cells that is characterized by enhanced aerobic glycolysis. Our data revealed that 3BP induced depletion of energetic capabilities of glioma cells. 3BP induced H2O2 production as a novel mechanism of its action. C6 glioma transfected with DAO and treated with D-serine together with 3BP-sensitized glioma cells to 3BP and decreased markedly proliferation, clonogenic power and viability in a three-dimensional tumor model with lesser effect on normal astrocytes. DAO gene therapy using atelocollagen as an in vivo transfection agent proved effective in a glioma tumor model in Sprague-Dawley (SD) rats, especially after combination with 3BP. OSED treatment was safe and tolerable in SD rats. OSED therapy may be a promising therapeutic modality for glioma. PMID:21921941

El Sayed, S M; Abou El-Magd, R M; Shishido, Y; Chung, S P; Sakai, T; Watanabe, H; Kagami, S; Fukui, K

2011-09-16

246

Mitochondrial cytochrome c oxidase subunit 1 (cox1) gene sequence of Spirocerca lupi (Nematoda, Spirurida): avenues for potential implications.  

PubMed

Canine spirocercosis is a life-threatening parasitosis caused by Spirocerca lupi (Nematoda, Spirurida) that is presently emerging in several countries. This study characterised an informative region within the mitochondrial (mtDNA) gene encoding for the cytochrome c oxidase subunit 1 (cox1) of S. lupi by Polymerase Chain Reaction (PCR)-coupled sequencing. Specimens from five different countries in Europe, Asia and Africa were examined and two different sequence variants of cox1 (i.e. haplotypes) were determined, displaying nucleotidic variation at 6 of 689 positions. All of these positions were invariable among all the parasite individuals from Europe (haplotype 1) and among the African and Asian individuals (haplotype 2), but differed between Europe and Asia/Africa. The S. lupi cox1 sequences were consistent with those of other common Spirurida previously reported at both nucleotidic and phylogenetic levels. This study provides molecular information essential for identification of the nematode, irrespective of its life cycle stage. Crucial implications for the specific molecular diagnosis of clinical spirocercosis and investigation of the evolution, population genetics, ecology and epidemiology of S. lupi are discussed. PMID:17428608

Traversa, Donato; Costanzo, Francesca; Iorio, Raffaella; Aroch, Itamar; Lavy, Eran

2007-04-10

247

Expression of alternative oxidase in tomato  

SciTech Connect

Tomato fruit ripening is characterized by an increase in ethylene biosynthesis, a burst in respiration (i.e. the climacteric), fruit softening and pigmentation. As whole tomatoes ripened from mature green to red, there was an increase in the alternative oxidase capacity. Aging pink tomato slices for 24 and 48 hrs also showed an increase of alternative oxidase and cytochrome oxidase capacities. Monoclonal antibodies prepared to the Sauromatum guttatum alternative oxidase were used to follow the appearance of alternative oxidase in tomato fruits. There is a corresponding increase in a 36kDa protein with an increase in alternative oxidase capacity. Effects of ethylene and norbornadiene on alternative oxidase capacity were also studied. We are using an alternative oxidase cDNA clone from potato to study the expression of mRNA in ripening and wounded tomatoes to determine if the gene is transcriptionally regulated.

Kakefuda, M.; McIntosh, L. (Michigan State Univ., East Lansing (USA))

1990-05-01

248

Variation in the Lysyl Oxidase (LOX) Gene Is Associated with Keratoconus in Family-Based and Case-Control Studies  

PubMed Central

Purpose. Keratoconus is a bilateral noninflammatory progressive corneal disorder with complex genetic inheritance and a common cause for cornea transplantation in young adults. A genomewide linkage scan in keratoconus families identified a locus at 5q23.2, overlapping the gene coding for the lysyl oxidase (LOX). LOX encodes an enzyme responsible for collagen cross-linking in a variety of tissues including the cornea. Corneal collagen cross-linking with long-wave ultraviolet light and riboflavin is a promising new treatment for keratoconus. To determine whether LOX is a genetic determinant of the pathogenesis of keratoconus, we analyzed association results of LOX polymorphisms in two independent case-control samples and in keratoconus families. Methods. Association results were analyzed of single-nucleotide polymorphisms (SNPs) in the LOX gene from a Genome-Wide Association Study (GWAS) investigation in two independent panels of patients with keratoconus and controls and in keratoconus families. Results. Evidence of association was found at SNPs rs10519694 and rs2956540 located in intron 4 of LOX in the GWAS discovery case-control panel with P values of 2.3 × 10?3 and 7 × 10?3, respectively. The same two SNPs were found to be associated with keratoconus by family-based association testing with P values of 2.7 × 10?3 and 7.7 × 10?4, respectively. Meta P values of 4.0 × 10?5 and 4.0 × 10?7 were calculated for SNPs rs10519694 and rs2956540 by analyzing case-control and family samples simultaneously. Sequencing of LOX exons in a subset of keratoconus patients identified two polymorphisms, rs1800449 and rs2288393, located in LOX transcripts I and II, associated with keratoconus in case-control and family samples with a meta P value of 0.02. Conclusions. Results provided strong genetic evidence that LOX variants lead to increased susceptibility to developing of keratoconus.

Bykhovskaya, Yelena; Li, Xiaohui; Epifantseva, Irina; Haritunians, Talin; Siscovick, David; Aldave, Anthony; Szczotka-Flynn, Loretta; Iyengar, Sudha K.; Taylor, Kent D.; Rotter, Jerome I.; Rabinowitz, Yaron S

2012-01-01

249

Differentiation of Serpulina species by NADH oxidase gene (nox) sequence comparisons and nox-based polymerase chain reaction tests.  

PubMed

The NADH oxidase genes (nox) of 18 strains of intestinal spirochaetes were partially sequenced over 1246 bases. Strains examined included 17 representatives from six species of the genus Serpulina, and the type strain 513A(T) of the human intestinal spirochaete Brachyspira aalborgi. Sequences were aligned and used to investigate phylogenetic relationships between the organisms. Nox sequence identities between strains within the genus Serpulina were within the range 86.3-100%, whilst the nox gene of B. aalborgi shared between 78.8-83.0% sequence identity with the nox sequences of the various Serpulina strains. A phenogram produced based on sequence dissimilarities was in good agreement with the current classification of species in the genus Serpulina, although an atypical strongly beta-haemolytic porcine strain (P280/1), previously thought to be S. innocens, appeared distinct from other members of this species. Primer pairs were developed from the nox sequence alignments for use in polymerase chain reaction (PCR) identification of the pathogenic species S. hyodysenteriae (NOX1), S. intermedia (NOX2), and S. pilosicoli (NOX3), and for the combined non-pathogenic species S. innocens and S. murdochii (NOX4). The PCRs were optimised using 80 strains representing all currently described species in the genus Serpulina, as well as the type strain of B. aalborgi. Tests NOX1 and NOX4 specifically amplified DNA from all members of their respective target species, whilst tests NOX2 and NOX3 were less sensitive. NOX2 amplified DNA from all 10 strains of S. intermedia from pigs but from only 4 of 10 strains from chickens, whilst NOX3 amplified DNA from only 18 of 21 S. pilosicoli strains, even at low stringency. Tests NOX1 and NOX4 should prove useful in veterinary diagnostic laboratories, whilst NOX2 and NOX3 require further refinement. PMID:10392777

Atyeo, R F; Stanton, T B; Jensen, N S; Suriyaarachichi, D S; Hampson, D J

1999-06-01

250

No evidence for allelic association between bipolar disorder and monoamine oxidase A gene polymorphisms  

SciTech Connect

We have tested the hypothesis that DNA markers in the MAOA gene show allelic association with bipolar affective disorder. Eighty-four unrelated Caucasian patients with DSM III-R bipolar disorder and 84 Caucasian controls were typed for three markers in MAOA: a dinucleotide repeat in intron 2, a VNTR in intron 1, and an Fnu4HI RFLP in exon 8. No evidence for allelic association was observed between any of the markers and bipolar disorder. 9 refs., 1 tab.

Craddock, N.; Daniels, J.; Roberts, E. [Univ. of Wales, College of Medicine, Cardiff (United Kingdom)] [and others

1995-08-14

251

Unravelling mitochondrial retrograde regulation in the abiotic stress induction of rice ALTERNATIVE OXIDASE 1 genes.  

PubMed

Mitochondrial retrograde regulation (MRR) is the transduction of mitochondrial signals to mediate nuclear gene expression. It is not clear whether MRR is a common regulation mechanism in plant abiotic stress response. In this study, we analysed the early abiotic stress response of the rice OsAOX1 genes, and the induction of OsAOX1a and OsAOX1b (OsAOX1a/b) was selected as a working model for the stress-induced MRR studies. We found that the induction mediated by the superoxide ion (O2·(-) )-generating chemical methyl viologen was stronger than that of hydrogen peroxide (H2 O2 ). The addition of reactive oxygen species (ROS) scavengers demonstrated that the stress induction was reduced by eliminating O2·(-) . Furthermore, the stress induction did not rely on chloroplast- or cytosol-derived O2·(-) . Next, we generated transgenic plants overexpressing the superoxide dismutase (SOD) gene at different subcellular locations. The results suggest that only the mitochondrial SOD, OsMSD, attenuated the stress induction of OsAOX1a/b specifically. Therefore, our findings demonstrate that abiotic stress initiates the MRR on OsAOX1a/b and that mitochondrial O2·(-) is involved in the process. PMID:22994594

Li, Chun-Rong; Liang, Dan-Dan; Li, Juan; Duan, Yong-Bo; Li, Hao; Yang, Ya-Chun; Qin, Rui-Ying; Li, Li; Wei, Peng-Cheng; Yang, Jian-Bo

2012-10-19

252

Molecular characterization and chromosome assignment of the porcine gene COX7A1 coding for the muscle specific cytochrome c oxidase subunit VIIa-M.  

PubMed

The COX7A1 gene encodes a heart- and muscle-specific isoform of the subunit VIIA of cytochrome c oxidase, which is the last component of the mitochondrial electron transfer chain. Cloning and characterization of the porcine COX7A1 gene revealed a highly conserved organization with respect to other mammalian COX7A1 orthologs. The porcine gene consists of four exons spanning approximately 1.5 kb and codes for a peptide of 80 amino acids. The COX7A1 gene showed no variation between pigs from different breeds. The gene was assigned by FISH and RH-mapping to SSC 6q1.1-->q1.2 which is in agreement with previously established comparative maps. PMID:11856879

Drögemüller, C; Kuiper, H; Voss-Nemitz, R; Brenig, B; Distl, O; Leeb, T

2001-01-01

253

Co-occurrence of the Multicopper Oxidases Tyrosinase and Laccase in Lichens in Sub-order Peltigerineae  

PubMed Central

• Background and Aims Following previous findings of high extracellular redox activity in lichens and the presence of laccases in lichen cell walls, the work presented here additionally demonstrates the presence of tyrosinases. Tests were made for the presence of tyrosinases in 40 species of lichens, and from selected species their cellular location and molecular weights were determined. The effects of stress and inhibitors on enzyme activity were also studied. • Methods Tyrosinase and laccase activities were assayed spectrophotometrically using a variety of substrates. The molecular mass of the enzymes was estimated using polyacrylamide gel electrophoresis. • Key Results Extracellular tyrosinase and laccase activity was measured in 40 species of lichens from different taxonomic groupings and contrasting habitats. Out of 20 species tested from the sub-order Peltigerineae, all displayed significant tyrosinase and laccase activity, while activity was low or absent in other species tested. Representatives from both groups of lichens displayed low peroxidase activities. Identification of the enzymes as tyrosinases was confirmed by the ability of lichen thalli or leachates derived by shaking lichens in distilled water to metabolize substrates such as l-dihydroxyphenylalanine (DOPA), tyrosine and epinephrine readily in the absence of hydrogen peroxide, the sensitivity of the enzymes to the inhibitors cyanide, azide and hexylresorcinol, activation by SDS and having typical tyrosinase molecular masses of approx. 60?kDa. Comparing different species within the Peltigerineae showed that the activities of tyrosinases and laccase were correlated to each other. Desiccation and wounding stimulated laccase activity, while only wounding stimulated tyrosinase activity. • Conclusions Cell walls of lichens in sub-order Peltigerineae have much higher activities and a greater diversity of cell wall redox enzymes compared with other lichens. Possible roles of tyrosinases include melanization, removal of toxic phenols or quinones, and production of herbivore deterrents.

LAUFER, ZSANETT; BECKETT, RICHARD P.; MINIBAYEVA, FARIDA V.

2006-01-01

254

Monoamine oxidase a and B gene polymorphisms and negative and positive symptoms in schizophrenia.  

PubMed

Given that schizophrenia is a heterogeneous disorder, the analysis of clinical characteristics could help to identify homogeneous phenotypes that may be of relevance in genetic studies. Linkage and association studies have suggested that a locus predisposing to schizophrenia may reside within Xp11. We analyzed uVNTR and rs1137070, polymorphisms from MAOA and rs1799836 of MAOB genes to perform single SNP case-control association study in a sample of 344 schizophrenia patients and 124 control subjects. Single polymorphism analysis of uVNTR, rs1137070 and rs1799836 SNPs did not show statistical differences between cases and controls. Multivariate ANOVA analysis of clinical characteristics showed statistical differences between MAOB/rs1799836 and affective flattening scores (F = 4.852, P = 0.009), and significant association between MAOA/uVNTR and affective flattening in female schizophrenia patients (F = 4.236, P = 0.016) after Bonferroni's correction. Our preliminary findings could suggest that severity of affective flattening may be associated by modifier variants of MAOA and MAOB genes in female Mexican patients with schizophrenia. However, further large-scale studies using quantitative symptom-based phenotypes and several candidate variants should be analyzed to obtain a final conclusion. PMID:23738213

Camarena, Beatriz; Fresán, Ana; Aguilar, Alejandro; Escamilla, Raúl; Saracco, Ricardo; Palacios, Jorge; Tovilla, Alfonso; Nicolini, Humberto

2012-04-19

255

[Identification of mutations in the protoporphyrin oxidase gene and its diagnostic implications in porphyria variegata in Chile].  

PubMed

Variegate porphyria (VP) results from a hereditary deficiency of protoporphyrinogen oxidase (PPOX) that is transmitted in an autosomal dominan fashion. The diagnosis is based on the clinical symptoms and is confirmed biochemically. Sometimes, however, these diagnostic tools reveal limitations in establishing the definitive diagnosis of the prevailing type of acute porphyria. In these patients, molecular genetic analyses can be useful. We performed molecular genetic studies in 13 Chilean families by PCR amplification of the PPOX gene, conformation sensitive gel electrophoresis, and automated DNA sequencing. In five symptomatic patients from different families, respectively, the biochemical data confirmed the diagnosis of VP. In seven other families, however, the biochemical studies were not conclusive. Furthermore, the original biochemical analysis in one clinically severely affected patient from a further family even suggested the diagnosis of erythropoietic protoporphyria (EPP). Beside the respective index patients, we studied 78 asymptomatic family members and 50 healthy, unrelated individuals for control purposes. In five families, the previous diagnosis of VP could be confirmed genetically. Further, half of the asymptomatic relatives revealed a mutation in the PPOX gene, consisting of three missense mutations and two deletion mutations. Mutation R168H that had been already described previously in German VP families was found in a Chilean family of German origin. Further, two novel missense mutations, designated L74P and G232S, could be detected. In four Chilean families, we found the deletion 1330deICT that had also been previously described in three Swedish VP families. The second deletion, 1239delTACAC, has not been described anywhere else but Chile and could be identified in seven families. One patient who was initially diagnosed with EPP turned out to be a compound heterozygote for mutations on both alleles of the PPOX gene. In conclusion, our molecular genetic analyses unequivocally confirmed the diagnosis of VP in seven families who originally had revealed inconclusive biochemical data. Further, early genetic analysis allows for the identification of asymptomatic mutation carriers, thereby offering the possibility of adequate counselling and the prevention of potentially life-threatening acute porphyric attacks. PMID:17146940

Wolff, Carlos; Frank, Jorge; Poblete-Gutiérrez, Pamela

256

Gibberellin 3-oxidase Gene Expression Patterns Influence Gibberellin Biosynthesis, Growth, and Development in Pea.  

PubMed

Gibberellins (GAs) are key modulators of plant growth and development. PsGA3ox1 (LE) encodes a GA 3?-hydroxylase that catalyzes the conversion of GA20 to biologically active GA1. To further clarify the role of GA3ox expression during pea (Pisum sativum) plant growth and development, we generated transgenic pea lines (in a lele background) with cauliflower mosaic virus-35S-driven expression of PsGA3ox1 (LE). PsGA3ox1 transgene expression led to higher GA1 concentrations in a tissue-specific and development-specific manner, altering GA biosynthesis and catabolism gene expression and plant phenotype. PsGA3ox1 transgenic plants had longer internodes, tendrils, and fruits, larger stipules, and displayed delayed flowering, increased apical meristem life, and altered vascular development relative to the null controls. Transgenic PsGA3ox1 overexpression lines were then compared with lines where endogenous PsGA3ox1 (LE) was introduced, by a series of backcrosses, into the same genetic background (BC LEle). Most notably, the BC LEle plants had substantially longer internodes containing much greater GA1 levels than the transgenic PsGA3ox1 plants. Induction of expression of the GA deactivation gene PsGA2ox1 appears to make an important contribution to limiting the increase of internode GA1 to modest levels for the transgenic lines. In contrast, PsGA3ox1 (LE) expression driven by its endogenous promoter was coordinated within the internode tissue to avoid feed-forward regulation of PsGA2ox1, resulting in much greater GA1 accumulation. These studies further our fundamental understanding of the regulation of GA biosynthesis and catabolism at the tissue and organ level and demonstrate that the timing/localization of GA3ox expression within an organ affects both GA homeostasis and GA1 levels, and thereby growth. PMID:23979969

Reinecke, Dennis M; Wickramarathna, Aruna D; Ozga, Jocelyn A; Kurepin, Leonid V; Jin, Alena L; Good, Allen G; Pharis, Richard P

2013-08-26

257

Allelic variation of polyphenol oxidase (PPO) genes located on chromosomes 2A and 2D and development of functional markers for the PPO genes in common wheat.  

PubMed

Polyphenol oxidase (PPO) activity is highly related to the undesirable browning of wheat-based end products, especially Asian noodles. Characterization of PPO genes and the development of their functional markers are of great importance for marker-assisted selection in wheat breeding. In the present study, complete genomic DNA sequences of two PPO genes, one each located on chromosomes 2A and 2D and their allelic variants were characterized by means of in silico cloning and experimental validation. Sequences were aligned at both DNA and protein levels. Two haplotypes on chromosome 2D showed 95.2% sequence identity at the DNA level, indicating much more sequence diversity than those on chromosome 2A with 99.6% sequence identity. Both of the PPO genes on chromosomes 2A and 2D contain an open reading frame (ORF) of 1,731 bp, encoding a PPO precursor peptide of 577 amino acids with a predicted molecular mass of approximately 64 kD. Two complementary dominant STS markers, PPO16 and PPO29, were developed based on the PPO gene haplotypes located on chromosome 2D; they amplify a 713-bp fragment in cultivars with low PPO activity and a 490-bp fragment in those with high PPO activity, respectively. The two markers were mapped on chromosome 2DL using a doubled haploid population derived from the cross Zhongyou 9507/CA9632, and a set of nullisomic-tetrasomic lines and ditelosomic line 2DS of Chinese Spring. QTL analysis indicated that the PPO gene co-segregated with the two STS markers and was closely linked to SSR marker Xwmc41 on chromosome 2DL, explaining from 9.6 to 24.4% of the phenotypic variance for PPO activity across three environments. In order to simultaneously detect PPO loci on chromosomes 2A and 2D, a multiplexed marker combination PPO33/PPO16 was developed and yielded distinguishable DNA patterns in a number of cultivars. The STS marker PPO33 for the PPO gene on chromosome 2A was developed from the same gene sequences as PPO18 that we reported previously, and can amplify a 481-bp and a 290-bp fragment from cultivars with low and high PPO activity, respectively. A total of 217 Chinese wheat cultivars and advanced lines were used to validate the association between the polymorphic fragments and grain PPO activity. The results showed that the marker combination PPO33/PPO16 is efficient and reliable for evaluating PPO activity and can be used in wheat breeding programs aimed for noodle and other end product quality improvement. PMID:17426955

He, X Y; He, Z H; Zhang, L P; Sun, D J; Morris, C F; Fuerst, E P; Xia, X C

2007-04-11

258

Oxidase Test Protocol  

NSDL National Science Digital Library

The oxidase test is used to detect the presence of the enzyme cytochrome oxidase in microorganisms.  While used as a taxonomic tool for many microorganisms, the test was established initially to differentiate Neisseria spp. (oxidase positive) from Acinetobacter (oxidase negative) and Pseudomonas spp. (oxidase positive) from the Enterobacteriaceae (oxidase negative).

American Society For Microbiology;

2010-11-11

259

Visual expression analysis of the responses of the alternative oxidase gene ( aox1) to heat shock, oxidative, and osmotic stresses in conidia of citric acid-producing Aspergillus niger  

Microsoft Academic Search

The citric acid-producing filamentous fungus Aspergillus niger WU-2223L shows cyanide-insensitive respiration catalyzed by alternative oxidase in addition to the cytochrome pathway. Sequence analysis of the 5’ flanking region of the alternative oxidase gene (aox1) revealed a potential heat shock element (HSE) and a stress response element (STRE). We have previously confirmed aox1 expression in conidia. In this study, to confirm

Yuki Honda; Takasumi Hattori; Kohtaro Kirimura

260

Amino Acid Catabolism by an areA-Regulated Gene Encoding an l-Amino Acid Oxidase with Broad Substrate Specificity in Aspergillus nidulans  

PubMed Central

The filamentous fungus Aspergillus nidulans can use a wide range of compounds as nitrogen sources. The synthesis of the various catabolic enzymes needed to breakdown these nitrogen sources is regulated by the areA gene, which encodes a GATA transcription factor required to activate gene expression under nitrogen-limiting conditions. The areA102 mutation results in pleiotropic effects on nitrogen source utilization, including better growth on certain amino acids as nitrogen sources. Mutations in the sarA gene were previously isolated as suppressors of the strong growth of an areA102 strain on l-histidine as a sole nitrogen source. We cloned the sarA gene by complementation of a sarA mutant and showed that it encodes an l-amino acid oxidase enzyme with broad substrate specificity. Elevated expression of this enzyme activity in an areA102 background accounts for the strong growth of these strains on amino acids that are substrates for this enzyme. Loss of function sarA mutations, which abolish the l-amino acid oxidase activity, reverse the areA102 phenotype. Growth tests with areA102 and sarA mutants show that this enzyme is the primary route of catabolism for some amino acids, while other amino acids are metabolized through alternative pathways that yield either ammonium or glutamate for growth.

Davis, Meryl A.; Askin, Marion C.; Hynes, Michael J.

2005-01-01

261

Systematic screening of lysyl oxidase-like (LOXL) family genes demonstrates that LOXL2 is a susceptibility gene to intracranial aneurysms.  

PubMed

Four lysyl oxidase family genes (LOXL1, LOXL2, LOXL3, and LOXL4), which catalyze cross-linking of collagen and elastin, were considered to be functional candidates for intracranial aneurysms (IA) and were extensively screened for genetic susceptibility in Japanese IA patients. Total RNA was isolated from four paired ruptured IA and superficial temporal artery (STA) tissue and examined by real-time RT-PCR. The expression of LOXL2 in the paired IA and STA tissues was elevated in the IA tissue. A total of 55 single nucleotide polymorphisms (SNPs) of LOXL1-4 were genotyped for an allelic association study in 402 Japanese IA patients and 462 Japanese non-IA controls. Allelic associations were evaluated with the chi-square test and the permutation test especially designed for adjustment of multiple testing. SNPs of LOXL1 and LOXL4 were not significantly associated with IA, while several SNPs of LOXL2 and LOXL3 showed nominally significant associations in IA patients. We detected an empirically significant association with one SNP of LOXL2 in familial IA patients after adjustment for multiple testing [chi(2) = 10.23, empirical P = 0.023, OR (95% CI) = 1.49 (1.17, 1.90)]. Furthermore, multilocus interaction was evaluated by multifactor dimensionality reduction analysis. We found that the SNPs of LOXL2 have an interactive effect with elastin (ELN) and LIM kinase 1 (LIMK1) that have been previously found to be associated with IA. In conclusion, one SNP of LOXL2 showed a significant association with IA individually, and we also detected a gene-gene interaction of LOXL2 with ELN/LIMK1, which may play an important role in susceptibility to IA. PMID:17287949

Akagawa, Hiroyuki; Narita, Akira; Yamada, Haruhiko; Tajima, Atsushi; Krischek, Boris; Kasuya, Hidetoshi; Hori, Tomokatsu; Kubota, Motoo; Saeki, Naokatsu; Hata, Akira; Mizutani, Tohru; Inoue, Ituro

2007-02-08

262

Comprehensive Set of Integrative Plasmid Vectors for Copper-Inducible Gene Expression in Myxococcus xanthus  

PubMed Central

Myxococcus xanthus is widely used as a model system for studying gliding motility, multicellular development, and cellular differentiation. Moreover, M. xanthus is a rich source of novel secondary metabolites. The analysis of these processes has been hampered by the limited set of tools for inducible gene expression. Here we report the construction of a set of plasmid vectors to allow copper-inducible gene expression in M. xanthus. Analysis of the effect of copper on strain DK1622 revealed that copper concentrations of up to 500 ?M during growth and 60 ?M during development do not affect physiological processes such as cell viability, motility, or aggregation into fruiting bodies. Of the copper-responsive promoters in M. xanthus reported so far, the multicopper oxidase cuoA promoter was used to construct expression vectors, because no basal expression is observed in the absence of copper and induction linearly depends on the copper concentration in the culture medium. Four different plasmid vectors have been constructed, with different marker selection genes and sites of integration in the M. xanthus chromosome. The vectors have been tested and gene expression quantified using the lacZ gene. Moreover, we demonstrate the functional complementation of the motility defect caused by lack of PilB by the copper-induced expression of the pilB gene. These versatile vectors are likely to deepen our understanding of the biology of M. xanthus and may also have biotechnological applications.

Gomez-Santos, Nuria; Treuner-Lange, Anke; Moraleda-Munoz, Aurelio; Garcia-Bravo, Elena; Garcia-Hernandez, Raquel; Martinez-Cayuela, Marina; Perez, Juana; S?gaard-Andersen, Lotte

2012-01-01

263

Isolation and Purification of Pyranose 2-Oxidase from Phanerochaete chrysosporium and Characterization of Gene Structure and Regulation  

PubMed Central

Pyranose 2-oxidase (POX) was recovered from Phanerochaete chrysosporium BKM-F-1767 solid substrate culture using mild extraction conditions and was purified. 13C-nuclear magnetic resonance confirmed production of d-arabino-hexos-2-ulose (glucosone) from d-glucose with the oxidase. Peptide fingerprints generated by liquid chromatography-tandem mass spectrometry of tryptic digests and analysis of the corresponding cDNA revealed a structurally unusual sequence for the P. chrysosporium POX. Relatively high levels of pox transcript were detected under carbon-starved culture conditions but not under nutrient sufficiency. This regulation pattern is similar to that observed for lignin peroxidases, manganese peroxidases, and glyoxal oxidase of P. chrysosporium, supporting evidence that POX has a role in lignocellulose degradation.

de Koker, Theodorus H.; Mozuch, Michael D.; Cullen, Daniel; Gaskell, Jill; Kersten, Philip J.

2004-01-01

264

The Bradyrhizobium japonicum fixGHIS genes are required for the formation of the high-affinity cbb3-type cytochrome oxidase  

Microsoft Academic Search

We report structural and functional analyses of the Bradyrhizobium japonicum\\u000a \\u000a fixGHIS genes, which map immediately downstream of the fixNOQP operon for the symbiotically essential cbb\\u000a \\u000a 3-type heme-copper oxidase complex. Expression of fixGHIS, like that of fixNOQP, is strongly induced in cells grown microaerobically or anaerobically. A fixGHI deletion led to the same prominent phenotypes as those known from a fixNOQP

Oliver Preisig; Rachel Zufferey; Hauke Hennecke

1996-01-01

265

Conversion of pipecolic acid into lysine in Penicillium chrysogenum requires pipecolate oxidase and saccharopine reductase: characterization of the lys7 gene encoding saccharopine reductase.  

PubMed

Pipecolic acid is a component of several secondary metabolites in plants and fungi. This compound is useful as a precursor of nonribosomal peptides with novel pharmacological activities. In Penicillium chrysogenum pipecolic acid is converted into lysine and complements the lysine requirement of three different lysine auxotrophs with mutations in the lys1, lys2, or lys3 genes allowing a slow growth of these auxotrophs. We have isolated two P. chrysogenum mutants, named 7.2 and 10.25, that are unable to convert pipecolic acid into lysine. These mutants lacked, respectively, the pipecolate oxidase that converts pipecolic acid into piperideine-6-carboxylic acid and the saccharopine reductase that catalyzes the transformation of piperideine-6-carboxylic acid into saccharopine. The 10.25 mutant was unable to grow in Czapek medium supplemented with alpha-aminoadipic acid. A DNA fragment complementing the 10.25 mutation has been cloned; sequence analysis of the cloned gene (named lys7) revealed that it encoded a protein with high similarity to the saccharopine reductase from Neurospora crassa, Magnaporthe grisea, Saccharomyces cerevisiae, and Schizosaccharomyces pombe. Complementation of the 10.25 mutant with the cloned gene restored saccharopine reductase activity, confirming that lys7 encodes a functional saccharopine reductase. Our data suggest that in P. chrysogenum the conversion of pipecolic acid into lysine proceeds through the transformation of pipecolic acid into piperideine-6-carboxylic acid, saccharopine, and lysine by the consecutive action of pipecolate oxidase, saccharopine reductase, and saccharopine dehydrogenase. PMID:11717275

Naranjo, L; Martin de Valmaseda, E; Bañuelos, O; Lopez, P; Riaño, J; Casqueiro, J; Martin, J F

2001-12-01

266

CLONING OF RED CLOVER AND ALFALFA POLYPHENOL OXIDASE GENES AND EXPRESSION OF ACTIVE ENZYMES IN TRANSGENIC ALFALFA  

Technology Transfer Automated Retrieval System (TEKTRAN)

Red clover contains high levels of polyphenol oxidase (PPO) activity and o-diphenol substrates. This results in a characteristic post-harvest browning reaction associated with decreased protein degradation during ensiling. To define PPO's role in inhibition of post-harvest proteolysis, we are taking...

267

Genetic and in silico comparative mapping of the polyphenol oxidase gene in bread wheat ( Triticum aestivum L.)  

Microsoft Academic Search

Polyphenol oxidases (PPOs) are involved in the time-dependent darkening and discolouration of Asian noodles and other wheat end products. In this study, a doubled haploid (DH) population derived from Chara (moderately high PPO activity)\\/WW2449 (low PPO activity) was screened for PPO activity based on

Rosy Raman; Harsh Raman; Katie Johnstone; Chris Lisle; Alison Smith; Peter Matin; Helen Allen

2005-01-01

268

Cytochrome c oxidase subunit III (COX3) gene, an informative marker for phylogenetic analysis and differentiation of Babesia species in China.  

PubMed

In this study a 552-bp region of the cytochrome c oxidase subunit III (COX3) was amplified by polymerase chain reaction (PCR) and sequenced from individual Babesia species. Sequence variation between Babesia species from China ranged between 0 and 32.4%. We analyzed the phylogenetic performance of the partial sequence of the COX3 gene to resolve Babesia relationships as compared to the nuclear 18S rRNA and the mitochondrial cytochrome b (COB) gene, These data indicate that the COX3 gene seems to be superior to the COB gene and the 18S rRNA in recognizing close lineages among some Babesia species. Our work indicates that the COX3 gene does complement and corroborate the phylogenetic inferences observed with the nuclear 18S rRNA and the COB gene previously reported. The combined phylogenetic analysis based on the nuclear 18S rRNA and the COX3 gene significantly improved (bootstrap) intraspecies support of the phylogenetic relationship. The presence of additional variable sites in the COX3 gene allowed an improved interspecies differentiation of Babesia species in this study. The data could be applicable for the survey of parasite dynamics, epidemiological studies as well as prevention and control of the disease. PMID:23619098

Tian, Zhancheng; Liu, Guangyuan; Yin, Hong; Luo, Jianxun; Guan, Guiquan; Xie, Junren; Luo, Jin; Zheng, Jinfeng; Tian, Meiyuan; Yuan, Xiaosong; Wang, Fangfang; Chen, Ronggui; Wang, Haijun

2013-04-22

269

Association of NADPH oxidase p22phox gene C242T, A640G and -930A/G polymorphisms with primary knee osteoarthritis in the Greek population.  

PubMed

Osteoarthritis (OA) is the most common form of arthritis with still unknown pathogenic etiology and considerable contribution of genetic factors. Recently, a new emerging role of oxidative stress in the pathology of OA has been reported, lacking however elucidation of the underlying mechanism. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase being a complex enzyme produced by chondrocytes, presents the major source of reactive oxygen species and main contributor of increased oxidative stress. The present study aims to evaluate the association of NADPH oxidase p22phox gene C242T, A640G and -A930G polymorphisms with primary knee OA in the Greek population. One hundred fifty five patients with primary symptomatic knee OA participated in the study along with 139 matched controls. Genotypes were determined using polymerase chain reaction and restriction fragment length polymorphism technique. Allelic and genotypic frequencies were compared between both study groups. NADPH p22phox -A930G polymorphism was significantly associated with knee OA in the crude analysis (P = 0.018). No significant difference was detected for C242T and A640G polymorphisms (P > 0.05). The association between -A930G polymorphism and knee OA disappeared when the results were adjusted for obesity (P = 0.078, odds ratio 0.54, 95 % CI 0.272-1.071). The interaction between all three polymorphisms was not significant. The present study shows that NADPH oxidase p22phox gene C242T, A640G and -A930G polymorphisms are not risk factors for knee OA susceptibility in the Greek population. Further studies are needed to give a global view of the importance of this polymorphism in the pathogenesis of OA. PMID:23922196

Lepetsos, Panagiotis; Pampanos, Andreas; Lallos, Stergios; Kanavakis, Emmanouil; Korres, Dimitrios; Papavassiliou, Athanasios G; Efstathopoulos, Nicolaos

2013-08-07

270

Evidence for Lateral Transfer of Genes Encoding Ferredoxins, Nitroreductases, NADH Oxidase, and Alcohol Dehydrogenase 3 from Anaerobic Prokaryotes to Giardia lamblia and Entamoeba histolytica  

PubMed Central

Giardia lamblia and Entamoeba histolytica are amitochondriate, microaerophilic protists which use fermentation enzymes like those of bacteria to survive anaerobic conditions within the intestinal lumen. Genes encoding fermentation enzymes and related electron transport peptides (e.g., ferredoxins) in giardia organisms and amebae are hypothesized to be derived from either an ancient anaerobic eukaryote (amitochondriate fossil hypothesis), a mitochondrial endosymbiont (hydrogen hypothesis), or anaerobic bacteria (lateral transfer hypothesis). The goals here were to complete the molecular characterization of giardial and amebic fermentation enzymes and to determine the origins of the genes encoding them, when possible. A putative giardia [2Fe-2S]ferredoxin which had a hypothetical organelle-targeting sequence at its N terminus showed similarity to mitochondrial ferredoxins and the hydrogenosomal ferredoxin of Trichomonas vaginalis (another luminal protist). However, phylogenetic trees were star shaped, with weak bootstrap support, so we were unable to confirm or rule out the endosymbiotic origin of the giardia [2Fe-2S]ferredoxin gene. Putative giardial and amebic 6-kDa ferredoxins, ferredoxin-nitroreductase fusion proteins, and oxygen-insensitive nitroreductases each tentatively supported the lateral transfer hypothesis. Although there were not enough sequences to perform meaningful phylogenetic analyses, the unique common occurrence of these peptides and enzymes in giardia organisms, amebae, and the few anaerobic prokaryotes suggests the possibility of lateral transfer. In contrast, there was more robust phylogenetic evidence for the lateral transfer of G. lamblia genes encoding an NADH oxidase from a gram-positive coccus and a microbial group 3 alcohol dehydrogenase from thermoanaerobic prokaryotes. In further support of lateral transfer, the G. lamblia NADH oxidase and adh3 genes appeared to have an evolutionary history distinct from those of E. histolytica.

Nixon, Julie E. J.; Wang, Amy; Field, Jessica; Morrison, Hilary G.; McArthur, Andrew G.; Sogin, Mitchell L.; Loftus, Brendan J.; Samuelson, John

2002-01-01

271

Direct Identification of a Bacterial Manganese(II) Oxidase, the Multicopper Oxidase MnxG, from Spores of Several Different Marine Bacillus Species  

Microsoft Academic Search

Microorganisms catalyze the formation of naturally occurring Mn oxides, but little is known about the biochemical mechanisms of this important biogeochemical process. We used tandem mass spectrometry to directly analyze the Mn(II)-oxidizing enzyme from marine Bacillus spores, identified as an Mn oxide band with an in-gel activity assay. Nine distinct peptides recovered from the Mn oxide band of two Bacillus

Gregory J. Dick; Justin W. Torpey; Terry J. Beveridge; Bradley M. Tebo

2008-01-01

272

Phylogeographic analysis of the firefly, Luciola lateralis, in Japan and Korea based on mitochondrial cytochrome oxidase II gene sequences (Coleoptera: Lampyridae).  

PubMed

Luciola lateralis is widely distributed throughout the Korean Peninsula, northeast China, Sakhalin, and Japan. Two ecological types are recognized in Japan based on flash and hatching time characteristics. The mitochondrial cytochrome oxidase II gene was surveyed by restriction fragment length polymorphism analysis for Japan (46 populations) and Korea (two populations). Eleven haplotypes were detected. Gene trees revealed that haplotypes between Japan and Korea are much more differentiated in nucleotide sequences (8.1%) than those within Japan (0.3-1.4%) and Korea (0.7%). Haplotypes between Honshu and Hokkaido are not separated as clades, and the two ecological types cannot be segregated from each other phylogenetically. We suggest that the Japanese populations of this species may have dispersed within one million years ago and that ecological differences may be the result of physiological adaptation to cold climates. PMID:15524308

Suzuki, Hirobumi; Sato, Yasushi; Ohba, Nobuyoshi; Bae, Jin-Sik; Jin, Byung-Rae; Sohn, Hung-Dae; Kim, Sam-Eun

2004-10-01

273

A novel human lysyl oxidase-like gene (LOXL4) on chromosome 10q24 has an altered scavenger receptor cysteine rich domain.  

PubMed

We have identified a novel 14-exon human lysyl oxidase-like gene, LOXL4, on chromosome 10q24. The cDNA and derived amino acid sequence of LOXL4 demonstrates a conserved C-terminal region including the characteristic copper-binding site, lysyl and tyrosyl residues and a cytokine receptor-like domain. One of the four N-terminal SRCR domains contains a 13 amino acid insertion encoded by a short exon not present within the closely homologous LOXL2 and LOXL3 genes. The 3.5-kb LOXL4 mRNA is present in pancreas and testis and at lower levels in several other tissues. Fibroblasts, smooth muscle and osteosarcoma (HOS) cells express LOXL4. No expression was detected in HCT-116 and DLD-1 colon, MCF-7 breast and DU-145 prostate cancer cell lines. PMID:11691588

Asuncion, L; Fogelgren, B; Fong, K S; Fong, S F; Kim, Y; Csiszar, K

2001-11-01

274

The polyphenol oxidase gene family in poplar: phylogeny, differential expression and identification of a novel, vacuolar isoform  

Microsoft Academic Search

Polyphenol oxidases (PPOs) are oxidative enzymes that convert monophenols and o-diphenols to o-quinones using molecular oxygen. The quinone products are highly reactive following tissue damage and can interact with cellular\\u000a constituents and cause oxidative browning and cross-linking. The induction of PPO in some plants as a result of wounding,\\u000a herbivore attack, or pathogen infection has implicated them in defense. However,

Lan T. Tran; C. Peter Constabel

275

Isolation and characterization of a mutant protoporphyrinogen oxidase gene from Chlamydomonas reinhardtii conferring resistance to porphyric herbicides  

Microsoft Academic Search

In plant and algal cells, inhibition of the enzyme protoporphyrinogen oxidase (Protox) by the N-phenyl heterocyclic herbicide S-23142 causes massive protoporphyrin IX accumulation, resulting in membrane deterioration and cell lethality in the light. We have identified a 40.4 kb genomic fragment encoding S-23142 resistance by using transformation to screen an indexed cosmid library made from nuclear DNA of the dominant

Barbara L. Randolph-Anderson; Ryo Sato; Anita M. Johnson; Elizabeth H. Harris; Charles R. Hauser; Kenji Oeda; Fumiharu Ishige; Shoichi Nishio; Nicholas W. Gillham; John E. Boynton

1998-01-01

276

Cloning and Molecular Analyses of a Gibberellin 20Oxidase Gene Expressed Specifically in Developing Seeds of Watermelon  

Microsoft Academic Search

To understand the biosynthesis and functional role of gibberellins (GAs) in developing seeds, we isolated Cv20ox, a cDNA clone from watermelon (Citrullus lanatus) that shows significant amino acid homology with GA 20-oxidases. The complementary DNA clone was expressed in Escherichia coli as a fusion protein, which oxi- dized GA12 at C-20 to the C19 compound GA9, a precursor of bioactive

Hong-Gyu Kang; Sung-Hoon Jun; Junyul Kim; Hiroshi Kawaide; Yuji Kamiya

1999-01-01

277

Genomic Sequence and Organization of the Human Gene for Cytochrome c Oxidase Subunit (COX7A1) VIIa-M  

Microsoft Academic Search

Cytochrome c oxidase (COX, EC 1.9.3.1), the last component of the mitochondrial electron transfer chain, is built up by 13 polypeptides; 3 of them are encoded by the mitochondrial genome while the 10 smaller subunits are encoded by the nuclear genome. Several nuclear-encoded subunits occur in two different tissue-specific isoforms, a constitutive “L”-form and an “M”-form specific for skeletal and

Werner Wolz; Wolfram Kress; Clemens R. Mueller

1997-01-01

278

Activation of Human Monoamine Oxidase B Gene Expression by a Protein Kinase C MAPK Signal Transduction Pathway Involves c-Jun and Egr-1*  

PubMed Central

Monoamine oxidases (MAO) A and B deaminate a number of biogenic amines. Aberrant expression of MAO is implicated in several psychiatric and neurogenerative disorders. In this study, we have shown that phorbol 12-myristate 13-acetate (PMA) increases human MAO B, but not MAO A, gene expression. The sequence between ?246 and ?225 bp consists of overlapping binding sites (Sp1/Egr-1/Sp1) that are recognized by Sp1, Sp3, and PMA-inducible Egr-1 is essential for PMA activation. PMA transiently increases egr-1 and c-jun gene expression. Mutation studies show that Egr-1 and c-Jun transactivate the MAO B promoter and increase endogenous MAO B transcripts via the Sp1/Egr-1/Sp1 overlapping binding sites. Sp3 inhibits Sp1 and Egr-1 activation of MAO B gene expression. c-fos gene expression was increased by PMA but not involved in MAO B gene transcription. Furthermore, protein kinase C inhibitor blocks the PMA-dependent activation of MAO B. Co-transfection of the MAO B promoter with dominant negative forms of Ras, Raf-1, MEKK1, MEK1, MEK3, MEK7, ERK2, JNK1, and p38/RK inhibit the PMA-dependent activation of the MAO B promoter. These results indicate that MAO B expression is selectively induced by the activation of protein kinase C and MAPK signaling pathway and that c-Jun and Egr-1 appear to be the ultimate targets of this regulation.

Wong, Wai K.; Out, Xiao-Ming; Chen, Kevin; Shih, Jean C.

2010-01-01

279

Structure, Organization, and Transcriptional Regulation of a Family of Copper Radical Oxidase Genes in the Lignin-Degrading Basidiomycete Phanerochaete chrysosporium  

PubMed Central

The white rot basidiomycete Phanerochaete chrysosporium produces an array of nonspecific extracellular enzymes thought to be involved in lignin degradation, including lignin peroxidases, manganese peroxidases, and the H2O2-generating copper radical oxidase, glyoxal oxidase (GLX). Preliminary analysis of the P. chrysosporium draft genome had identified six sequences with significant similarity to GLX and designated cro1 through cro6. The predicted mature protein sequences diverge substantially from one another, but the residues coordinating copper and constituting the radical redox site are conserved. Transcript profiles, microscopic examination, and lignin analysis of inoculated thin wood sections are consistent with differential regulation as decay advances. The cro2-encoded protein was detected by liquid chromatography-tandem mass spectrometry in defined medium. The cro2 cDNA was successfully expressed in Aspergillus nidulans under the control of the A. niger glucoamylase promoter and secretion signal. The recombinant CRO2 protein had a substantially different substrate preference than GLX. The role of structurally and functionally diverse cro genes in lignocellulose degradation remains to be established.

Vanden Wymelenberg, Amber; Sabat, Grzegorz; Mozuch, Michael; Kersten, Philip J.; Cullen, Dan; Blanchette, Robert A.

2006-01-01

280

Structure, organization, and transcriptional regulation of a family of copper radical oxidase genes in the lignin-degrading basidiomycete Phanerochaete chrysosporium.  

PubMed

The white rot basidiomycete Phanerochaete chrysosporium produces an array of nonspecific extracellular enzymes thought to be involved in lignin degradation, including lignin peroxidases, manganese peroxidases, and the H2O2-generating copper radical oxidase, glyoxal oxidase (GLX). Preliminary analysis of the P. chrysosporium draft genome had identified six sequences with significant similarity to GLX and designated cro1 through cro6. The predicted mature protein sequences diverge substantially from one another, but the residues coordinating copper and constituting the radical redox site are conserved. Transcript profiles, microscopic examination, and lignin analysis of inoculated thin wood sections are consistent with differential regulation as decay advances. The cro2-encoded protein was detected by liquid chromatography-tandem mass spectrometry in defined medium. The cro2 cDNA was successfully expressed in Aspergillus nidulans under the control of the A. niger glucoamylase promoter and secretion signal. The recombinant CRO2 protein had a substantially different substrate preference than GLX. The role of structurally and functionally diverse cro genes in lignocellulose degradation remains to be established. PMID:16820482

Vanden Wymelenberg, Amber; Sabat, Grzegorz; Mozuch, Michael; Kersten, Philip J; Cullen, Dan; Blanchette, Robert A

2006-07-01

281

Identification and characterisation of a deletion (537delAT) in the protoporphyrinogen oxidase gene in a South African variegate porphyria family.  

PubMed

Variegate porphyria is an autosomal dominant disorder of haem metabolism resulting from a partial decrease in protoporphyrinogen oxidase activity. Variegate porphyria is highly prevalent in South Africa, the result of a founder effect now confirmed genetically as a single point mutation (R59W) which has been described in nearly all South African variegate porphyria patients studied. Only two other mutations (H20P, R168C) have been reported in South Africa. We utilised simultaneous, single-stranded conformational polymorphism and heteroduplex analysis, and direct sequencing to identify a further mutation; a 2 bp deletion in exon 6 which results in a premature stop codon 11 codons downstream from the mutation and is the first reported deletion in the protoporphyrinogen oxidase gene in a South African family. The familial segregation of this mutation strongly suggests that it is the disease causing mutation for variegate porphyria in this family. This further evidence for allelic heterogeneity limits the utility of tests for the R59W mutation in the diagnosis of variegate porphyria in South Africa. PMID:9829909

Corrigall, A V; Hift, R J; Hancock, V; Meissner, D; Davids, L; Kirsch, R E; Meissner, P N

1998-01-01

282

Histamine oxidation in mouse adipose tissue is controlled by the AOC3 gene-encoded amine oxidase  

Microsoft Academic Search

Introduction  Histaminergic status can modify adipose tissue (AT) development: histamine-free mice exhibit visceral obesity, and treatments\\u000a with H3-antagonists reduce body weight gain. However, direct histamine effects on AT remain poorly documented: it has been\\u000a observed that histamine stimulates lipolysis in rodent adipocytes when its oxidation by amine oxidases (AOs) is blocked by\\u000a inhibitors such as semicarbazide.\\u000a \\u000a \\u000a \\u000a \\u000a Objective  The aim of this work

Z. Iffiú-Soltész; E. Wanecq; D. Prévot; S. Grès; C. Carpéné

2010-01-01

283

Monoamine oxidase: A gene polymorphism, tryptophan hydroxylase gene polymorphism and antidepressant response to fluvoxamine in Japanese patients with major depressive disorder  

Microsoft Academic Search

Monoamine oxidase A (MAOA) and tryptophan hydroxylase (TPH) are the staple enzymes in the metabolism of serotonin (5-HT). The genetic polymorphisms of these two enzymes might individually alter the production, release, reuptake or degradation of 5-HT during the treatment of selective serotonin reuptake inhibitors (SSRIs), leading to the individual differences in the antidepressant effects of SSRIs. The authors investigated whether

Keizo Yoshida; Shingo Naito; Hitoshi Takahashi; Kazuhiro Sato; Kenichi Ito; Mitsuhiro Kamata; Hisashi Higuchi; Tetsuo Shimizu; Kunihiko Itoh; Kazuyuki Inoue; Takehiko Tezuka; Toshio Suzuki; Tadashi Ohkubo; Kazunobu Sugawara; Koichi Otani

2002-01-01

284

Bilirubin oxidase from Bacillus pumilus: a promising enzyme for the elaboration of efficient cathodes in biofuel cells.  

PubMed

A CotA multicopper oxidase (MCO) from Bacillus pumilus, previously identified as a laccase, has been studied and characterized as a new bacterial bilirubin oxidase (BOD). The 59 kDa protein containing four coppers, was successfully over-expressed in Escherichia coli and purified to homogeneity in one step. This 509 amino-acid enzyme, having 67% and 26% sequence identity with CotA from Bacillus subtilis and BOD from Myrothecium verrucaria, respectively, shows higher turnover activity towards bilirubin compared to other bacterial MCOs. The current density for O(2) reduction, when immobilized in a redox hydrogel, is only 12% smaller than the current obtained with Trachyderma tsunodae BOD. Under continuous electrocatalysis, an electrode modified with the new BOD is more stable, and has a higher tolerance towards NaCl, than a T. tsunodae BOD modified electrode. This makes BOD from B. pumilus an attractive new candidate for application in biofuel cells (BFCs) and biosensors. PMID:22410485

Durand, Fabien; Kjaergaard, Christian Hauge; Suraniti, Emmanuel; Gounel, Sébastien; Hadt, Ryan G; Solomon, Edward I; Mano, Nicolas

2012-02-25

285

The cbb 3-type cytochrome c oxidase from Rhodobacter sphaeroides, a proton-pumping heme-copper oxidase  

Microsoft Academic Search

Rhodobactersphaeroides expresses a bb3-type quinol oxidase, and two cytochrome c oxidases: cytochrome aa3 and cytochrome cbb3. We report here the characterization of the genes encoding this latter oxidase. The ccoNOQP gene cluster of R. sphaeroides contains four open reading frames with high similarity to all ccoNOQP\\/fixNOQP gene clusters reported so far. CcoN has the six highly conserved histidines proposed to

Mayra Toledo-Cuevas; Blanca Barquera; Robert B Gennis; Mårten Wikström; J. Arturo Garc??a-Horsman

1998-01-01

286

Synthetic liver X receptor agonist T0901317 inhibits semicarbazide-sensitive amine oxidase gene expression and activity in apolipoprotein E knockout mice.  

PubMed

Semicarbazide-sensitive amine oxidase (SSAO) catalyzes oxidative deamination of primary aromatic and aliphatic amines. Increased SSAO activity has been found in atherosclerosis and diabetes mellitus. We hypothesize that the anti-atherogenic effect of liver X receptors (LXRs) might be related to the inhibition of SSAO gene expression and its activity. In this study, we investigated the effect of LXR agonist T0901317 on SSAO gene expression and its activity in apolipoprotein E knockout (apoE(-/-)) mice. Male apoE(-/-) mice (8 weeks old) were randomly divided into four groups: basal control group; vehicle group; prevention group; and treatment group. SSAO gene expression was analyzed by real-time quantitative polymerase chain reaction and its activity was determined. The activity of superoxide dismutase and content of malondialdehyde in the aorta and liver were also determined. In T0901317-treated mice, SSAO gene expression was significantly decreased in the aorta, liver, small intestine, and brain. SSAO activities in serum and in these tissues were also inhibited. The amount of superoxide dismutase in the aorta and liver of the prevention group and treatment group was significantly higher compared with the vehicle group (P<0.05). Malondialdehyde in the tissues of these two groups was significantly lower compared with the vehicle group (P<0.05). Our results showed that T0901317 inhibits SSAO gene expression and its activity in atherogenic apoE(-/-) mice. The atheroprotective effect of LXR agonist T0901317 is related to the inhibition of SSAO gene expression and its activity. PMID:18330481

Dai, Xiaoyan; Ou, Xiang; Hao, Xinrui; Cao, Dongli; Tang, Yaling; Hu, Yanwei; Li, Xiaoxu; Tang, Chaoke

2008-03-01

287

Functional analysis of the Trichoderma harzianum nox1 gene, encoding an NADPH oxidase, relates production of reactive oxygen species to specific biocontrol activity against Pythium ultimum.  

PubMed

The synthesis of reactive oxygen species (ROS) is one of the first events following pathogenic interactions in eukaryotic cells, and NADPH oxidases are involved in the formation of such ROS. The nox1 gene of Trichoderma harzianum was cloned, and its role in antagonism against phytopathogens was analyzed in nox1-overexpressed transformants. The increased levels of nox1 expression in these transformants were accompanied by an increase in ROS production during their direct confrontation with Pythium ultimum. The transformants displayed an increased hydrolytic pattern, as determined by comparing protease, cellulase, and chitinase activities with those for the wild type. In confrontation assays against P. ultimum the nox1-overexpressed transformants were more effective than the wild type, but not in assays against Botrytis cinerea or Rhizoctonia solani. A transcriptomic analysis using a Trichoderma high-density oligonucleotide (HDO) microarray also showed that, compared to gene expression for the interaction of wild-type T. harzianum and P. ultimum, genes related to protease, cellulase, and chitinase activities were differentially upregulated in the interaction of a nox1-overexpressed transformant with this pathogen. Our results show that nox1 is involved in T. harzianum ROS production and antagonism against P. ultimum. PMID:21421791

Montero-Barrientos, M; Hermosa, R; Cardoza, R E; Gutiérrez, S; Monte, E

2011-03-18

288

The origin of the Tibetan Mastiff and species identification of Canis based on mitochondrial cytochrome c oxidase subunit I (COI) gene and COI barcoding.  

PubMed

DNA barcoding is an effective technique to identify species and analyze phylogenesis and evolution. However, research on and application of DNA barcoding in Canis have not been carried out. In this study, we analyzed two species of Canis, Canis lupus (n = 115) and Canis latrans (n = 4), using the cytochrome c oxidase subunit I (COI) gene (1545 bp) and COI barcoding (648 bp DNA sequence of the COI gene). The results showed that the COI gene, as the moderate variant sequence, applied to the analysis of the phylogenesis of Canis members, and COI barcoding applied to species identification of Canis members. Phylogenetic trees and networks showed that domestic dogs had four maternal origins (A to D) and that the Tibetan Mastiff originated from Clade A; this result supports the theory of an East Asian origin of domestic dogs. Clustering analysis and networking revealed the presence of a closer relative between the Tibetan Mastiff and the Old English sheepdog, Newfoundland, Rottweiler and Saint Bernard, which confirms that many well-known large breed dogs in the world, such as the Old English sheepdog, may have the same blood lineage as that of the Tibetan Mastiff. PMID:22440462

Li, Y; Zhao, X; Pan, Z; Xie, Z; Liu, H; Xu, Y; Li, Q

2011-12-01

289

Evolutionary and structural analysis of the cytochrome c oxidase subunit I (COI) gene from Haematobia irritans, Stomoxys calcitrans and Musca domestica (Diptera: Muscidae) mitochondrial DNA.  

PubMed

This work describes the molecular characterization of the cytochrome c oxidase subunit I (COI) gene of the mitochondrial DNA from three species of great medical and veterinary importance: the horn fly, Haematobia irritans, the stable fly, Stomoxys calcitrans and the house fly, Musca domestica (Diptera: Muscidae) (Linnaeus). The nucleotide sequence in all species was 1536 bp in size and coded for a 512 amino acid peptide. The nucleotide bias for an A+T-rich sequence is linked to three features: a high A+T content throughout the entire gene, a high A+T content in the third codon position, and a predominance of A+T-rich codons. An anomalous TCG (serine) start codon was identified. Comparative analysis among members of the Muscidae, Scatophagidae, Calliphoridae and Drosophilidae showed high levels of nucleotide sequence conservation. Analysis of the divergent amino acids and COI protein topologies among these three Muscidae species agreed with the evolutionary model suggested for the insect mitochondrial COI protein. The characterization of the structure and evolution of this gene could be informative for further evolutionary analysis of dipteran species. PMID:16147869

de Oliveira, Marcos Túlio; de Azeredo-Espin, Ana Maria Lima; Lessinger, Ana Cláudia

2005-04-01

290

Numerous transcription initiation sites exist for the maize mitochondrial genes for subunit 9 of the ATP synthase and subunit 3 of cytochrome oxidase.  

PubMed Central

Transcripts for plant mitochondrial genes are frequently present as multiple size classes. In maize, these differences often result from variation in the 5' noncoding region. To determine where transcription initiates, primary (unprocessed) transcripts were specifically labeled in vitro by the capping reaction catalyzed by guanylyltransferase. Direct mapping of transcription initiation sites was accomplished by hybridization of in vitro-capped RNA with the 5' flanking sequences of mitochondrial genes and subsequent digestion with single-strand-specific RNases. The RNase protection experiments identified three transcription initiation sites for subunit 3 of cytochrome oxidase and at least six transcription initiation sites for subunit 9 of ATP synthase. Thus, transcript size heterogeneity is primarily the result of multiple transcription initiation sites for these genes rather than RNA processing. Primer extension analyses of maize mitochondrial RNA were used to precisely establish the sequences at the initiation sites. Comparison of sequences at transcription initiation sites suggests that some homology exists at these sites, although no highly conserved consensus sequence is obvious. Images

Mulligan, R M; Lau, G T; Walbot, V

1988-01-01

291

Gene environment interactions with a novel variable Monoamine Oxidase A transcriptional enhancer are associated with antisocial personality disorder.  

PubMed

Monoamine Oxidase A (MAOA) is a critical enzyme in the catabolism of monoaminergic neurotransmitters. MAOA transcriptional activity is thought to be regulated by a well characterized 30 base pair (bp) variable nucleotide repeat (VNTR) that lies approximately ?1000 bp upstream of the transcriptional start site (TSS). However, clinical associations between this VNTR genotype and behavioral states have been inconsistent. Herein, we describe a second, 10 bp VNTR that lies ?1500 bp upstream of the TSS. We provide in vitro and in silico evidence that this new VNTR region may be more influential in regulating MAOA transcription than the more proximal VNTR and that methylation of this CpG-rich VNTR is genotype dependent in females. Finally, we demonstrate that genotype at this new VNTR interacts significantly with history of child abuse to predict antisocial personality disorder (ASPD) in women and accounts for variance in addition to that explained by the prior VNTR. PMID:21554924

Philibert, Robert A; Wernett, Pamela; Plume, Jeff; Packer, Hans; Brody, Gene H; Beach, Steven R H

2011-05-07

292

Analysis of the 5? untranslated region (5?UTR) of the alcohol oxidase 1 (AOX1) gene in recombinant protein expression in Pichia pastoris  

PubMed Central

Pichia pastoris is a methylotrophic yeast that has been genetically engineered to express over one thousand heterologous proteins valued for industrial, pharmaceutical and basic research purposes. In most cases, the 5? untranslated region (UTR) of the alcohol oxidase 1 (AOX1) gene is fused to the coding sequence of the recombinant gene for protein expression in this yeast. Because the effect of the AOX1 5?UTR on protein expression is not known, site-directed mutagenesis was performed in order to decrease or increase the length of this region. Both of these types of changes were shown to affect translational efficiency, not transcript stability. While increasing the length of the 5?UTR clearly decreased expression of a ?-galactosidase reporter in a proportional manner, a deletion analysis demonstrated that the AOX1 5?UTR contains a complex mixture of both positive and negative cis-acting elements, suggesting that the construction of a synthetic 5?UTR optimized for a higher level of expression may be challenging.

Staley, Chris A.; Huang, Amy; Nattestad, Maria; Oshiro, Kristin T.; Ray, Laura E.; Mulye, Tejas; Li, Zhiguo Harry; Le, Thu; Stephens, Justin J.; Gomez, Seth R.; Moy, Allison D.; Nguyen, Jackson C.; Franz, Andreas H.; Lin-Cereghino, Joan; Lin-Cereghino, Geoff P.

2012-01-01

293

[Comparative analysis of variability of three mitochondrial genes of cytochrome oxidase complex (cox1, cox2, and cox3) in wild and domestic carp (Cyprinus carpio L.)].  

PubMed

For the first time, we studied the polymorphism of three mitochondrial genes of the cytochrome oxidase complex (cox1, cox2, and cox3) in natural populations of wild carp living in the Volga, Amur, and Don River Basins, as well as in European Hungarian carp and two pedigree lines of Ropsha carp of domestic breeding. The highest level of nucleotide and haplotype diversity in the studied samples was detected for the cox1 gene (pi = 0.61, h = 100%). Two lines of the Ropsha carp (pi = 0.61, h = 100%) and the Far East population of Amur wild carp from Shershikh strait (Am: pi = 0.20, h = 70%) were the most polymorphic for three genes. The second sample of Amur wild carp from the Amur River (Ac), as well as the samples of Volga and Don wild carp and Hungarian carp had lower values of variability. The presence of two main genealogical lines of the wild carp and carp was demonstrated based on the total sequence of three genes, as well as the corresponding amino acid sequences in the studied area. One of these lines (line I) is typical of the sample of Amur wild carp (Am) and three members of the Ropsha carp. Line II is developed by sequences of Volga, Don, and Amur wild carp (Ac), as well as European Hungarian carp and seven other members of the Ropsha carp. Three to four sublines, which differ in nucleotide and amino acid substitutions, were found within the lines. Possible reasons for the origin of genomic variability in wild carp, as well as in European and Russian breeds of carp, are discussed. PMID:23516901

Torgunakova, O A; Egorova, T A; Semenova, S K

2012-12-01

294

Phylogeography of stable fly (Diptera: Muscidae) estimated by diversity at ribosomal 16S and cytochrome oxidase I mitochondrial genes.  

PubMed

The blood-feeding cosmopolitan stable fly, Stomoxys calcitrans L. (Diptera: Muscidae), is thought to disperse rapidly and widely, and earlier studies of allozyme variation were consistent with high vagility in this species. The geographic origins of New World populations are unknown. Diversity at mitochondrial loci r16S and cytochrome oxidase I was examined in 277 stable flies from 11 countries, including five zoogeographical regions. Of 809 nucleotides, 174 were polymorphic and 133 were parsimony informative. Seventy-six haplotypes were found in frequencies consistent with the Wright-Fisher infinite allele model. None were shared among four or more zoogeographical regions. The null hypothesis of mutation neutrality was not rejected, thereby validating the observed distribution. Fifty-nine haplotypes were singular, eight were private and confined to the Old World, and three of 76 haplotypes were shared between the Old and New World. Only 19 haplotypes were found in the New World, 14 of which were singletons. Haplotype and nucleotide diversities were heterogeneous among countries and regions. The most diversity was observed in sub-Saharan Africa. Regional differentiation indices were C(RT) = 0.26 and N(RT) = 0.31, indicating populations were highly structured macrogeographically. Palearctic and New World flies were the least differentiated from each other. There were strong genetic similarities among populations in the Nearctic, Neotropical, and Palearctic regions, and it is most likely that New World populations were derived from the Palearctic after 1492 CE, in the colonial era. PMID:18047198

Marquez, J G; Cummings, M A; Krafsur, E S

2007-11-01

295

Clinical, biochemical, and neuropsychiatric evaluation of a patient with a contiguous gene syndrome due to a microdeletion Xp11.3 including the Norrie disease locus and monoamine oxidase (MAOA and MAOB) genes.  

PubMed

Norrie disease is a rare X-linked recessive disorder characterized by blindness from infancy. The gene for Norrie disease has been localized to Xp11.3. More recently, the genes for monoamine oxidase (MAOA, MAOB) have been mapped to the same region. This study evaluates the clinical, biochemical, and neuropsychiatric data in an affected male and 2 obligate heterozygote females from a single family with a submicroscopic deletion involving Norrie disease and MAO genes. The propositus was a profoundly retarded, blind male; he also had neurologic abnormalities including myoclonus and stereotopy-habit disorder. Both obligate carrier females had a normal IQ. The propositus' mother met diagnostic criteria for "chronic hypomania and schizotypal features." The propositus' MAO activity was undetectable and the female heterozygotes had reduced levels comparable to patients receiving MAO inhibiting antidepressants. MAO substrate and metabolite abnormalities were found in the propositus' plasma and CSF. This study indicates that subtle biochemical and possibly neuropsychiatric abnormalities may be detected in some heterozygotes with the microdeletion in Xp11.3 due to loss of the gene product for the MAO genes; this deletion can also explain some of the complex phenotype of this contiguous gene syndrome in the propositus. PMID:1308352

Collins, F A; Murphy, D L; Reiss, A L; Sims, K B; Lewis, J G; Freund, L; Karoum, F; Zhu, D; Maumenee, I H; Antonarakis, S E

1992-01-01

296

Duplicate polyphenol oxidase genes on barley chromosome 2H and their functional differentiation in the phenol reaction of spikes and grains.  

PubMed

Polyphenol oxidases (PPOs) are copper-containing metalloenzymes encoded in the nucleus and transported into the plastids. Reportedly, PPOs cause time-dependent discoloration (browning) of end-products of wheat and barley, which impairs their appearance quality. For this study, two barley PPO homologues were amplified using PCR with a primer pair designed in the copper binding domains of the wheat PPO genes. The full-lengths of the respective PPO genes were cloned using a BAC library, inverse-PCR, and 3'-RACE. Linkage analysis showed that the polymorphisms in PPO1 and PPO2 co-segregated with the phenol reaction phenotype of awns. Subsequent RT-PCR experiments showed that PPO1 was expressed in hulls and awns, and that PPO2 was expressed in the caryopses. Allelic variation of PPO1 and PPO2 was analysed in 51 barley accessions with the negative phenol reaction of awns. In PPO1, amino acid substitutions of five types affecting functionally important motif(s) or C-terminal region(s) were identified in 40 of the 51 accessions tested. In PPO2, only one mutant allele with a precocious stop codon resulting from an 8 bp insertion in the first exon was found in three of the 51 accessions tested. These observations demonstrate that PPO1 is the major determinant controlling the phenol reaction of awns. Comparisons of PPO1 single mutants and the PPO1PPO2 double mutant indicate that PPO2 controls the phenol reaction in the crease on the ventral side of caryopses. An insertion of a hAT-family transposon in the promoter region of PPO2 may be responsible for different expression patterns of the duplicate PPO genes in barley. PMID:20616156

Taketa, Shin; Matsuki, Kanako; Amano, Satoko; Saisho, Daisuke; Himi, Eiko; Shitsukawa, Naoki; Yuo, Takahisa; Noda, Kazuhiko; Takeda, Kazuyoshi

2010-07-08

297

A Penicillium expansum glucose oxidase-encoding gene, GOX2, is essential for gluconic acid production and acidification during colonization of deciduous fruit.  

PubMed

Penicillium expansum, the causal agent of blue mold rot, causes severe postharvest maceration of fruit through secretion of total, d-gluconic acid (GLA). Two P. expansum glucose oxidase (GOX)-encoding genes, GOX1 and GOX2, were analyzed. GOX activity and GLA accumulation were strongly related to GOX2 expression, which increased with pH to a maximum at pH 7.0, whereas GOX1 was expressed at pH 4.0, where no GOX activity or extracellular GLA were detected. This differential expression was also observed at the leading edge of the decaying tissue, where GOX2 expression was dominant. The roles of the GOX genes in pathogenicity were further studied through i) development of P. expansum goxRNAi mutants exhibiting differential downregulation of GOX2, ii) heterologous expression of the P. expansum GOX2 gene in the nondeciduous fruit-pathogen P. chrysogenum, and iii) modulation of GLA production by FeSO(4) chelation. Interestingly, in P. expansum, pH and GLA production elicited opposite effects on germination and biomass accumulation: 26% of spores germinated at pH 7.0 when GOX activity and GLA were highest whereas, in P. chrysogenum at the same pH, when GLA did not accumulate, 72% of spores germinated. Moreover, heterologous expression of P. expansum GOX2 in P. chrysogenum resulted in enhanced GLA production and reduced germination, suggesting negative regulation of spore germination and GLA production. These results demonstrate that pH modulation, mediated by GLA accumulation, is an important factor in generating the initial signal or signals for fungal development leading to host-tissue colonization by P. expansum. PMID:22352719

Barad, Shiri; Horowitz, Sigal Brown; Moscovitz, Oren; Lichter, Amnon; Sherman, Amir; Prusky, Dov

2012-06-01

298

Mitochondrial cytochrome c oxidase subunit 1 gene and nuclear rDNA regions of Enterobius vermicularis parasitic in captive chimpanzees with special reference to its relationship with pinworms in humans  

Microsoft Academic Search

Sequences of mitochondrial cytochrome c oxidase subunit 1 (CO1) gene, nuclear internal transcribed spacer 2 (ITS2) region of ribosomal DNA (rDNA), and 5S rDNA of Enterobius vermicularis from captive chimpanzees in five zoos\\/institutions in Japan were analyzed and compared with those of pinworm eggs from humans in Japan. Three major types of variants appearing in both CO1 and ITS2 sequences,

Tadao Nakano; Munehiro Okamoto; Yatsukaho Ikeda; Hideo Hasegawa

2006-01-01

299

NADPH oxidase inhibitor diphenyleneiodonium and reduced glutathione mitigate ethephon-mediated leaf senescence, H2O2 elevation and senescence-associated gene expression in sweet potato (Ipomoea batatas).  

PubMed

Ethephon, an ethylene releasing compound, promoted leaf senescence, H2O2 elevation, and senescence-associated gene expression in sweet potato. It also affected the glutathione and ascorbate levels, which in turn perturbed H2O2 homeostasis. The decrease of reduced glutathione and the accumulation of dehydroascorbate correlated with leaf senescence and H2O2 elevation at 72h in ethephon-treated leaves. Exogenous application of reduced glutathione caused quicker and significant increase of its intracellular level and resulted in the attenuation of leaf senescence and H2O2 elevation. A small H2O2 peak produced within the first 4h after ethephon application was also eliminated by reduced glutathione. Diphenyleneiodonium (DPI), an NADPH oxidase inhibitor, delayed leaf senescence and H2O2 elevation at 72h, and its influence was effective only within the first 4h after ethephon treatment. Ethephon-induced senescence-associated gene expression was repressed by DPI and reduced glutathione at 72h in pretreated leaves. Leaves treated with l-buthionine sulfoximine, an endogenous glutathione synthetase inhibitor, did enhance senescence-associated gene expression, and the activation was strongly repressed by reduced glutathione. In conclusion, ethephon-mediated leaf senescence, H2O2 elevation and senescence-associated gene expression are all alleviated by reduced glutathione and NADPH oxidase inhibitor DPI. The speed and the amount of intracellular reduced glutathione accumulation influence its effectiveness of protection against ethephon-mediated effects. Reactive oxygen species generated from NADPH oxidase likely serves as an oxidative stress signal and participates in ethephon signaling. The possible roles of NADPH oxidase and reduced glutathione in the regulation of oxidative stress signal in ethephon are discussed. PMID:23834930

Chen, Hsien-Jung; Huang, Chin-Shu; Huang, Guan-Jhong; Chow, Te-Jin; Lin, Yaw-Huei

2013-07-06

300

Oxygen-dependent expression of cytochrome c oxidase subunit 4-2 gene expression is mediated by transcription factors RBPJ, CXXC5 and CHCHD2  

PubMed Central

Cytochrome c oxidase (COX) is the terminal enzyme of the electron transport chain, made up of 13 subunits encoded by both mitochondrial and nuclear DNA. Subunit 4 (COX4), a key regulatory subunit, exists as two isoforms, the ubiquitous isoform 1 and the tissue-specific (predominantly lung) isoform 2 (COX4I2). COX4I2 renders lung COX about 2-fold more active compared with liver COX, which lacks COX4I2. We previously identified a highly conserved 13-bp sequence in the proximal promoter of COX4I2 that functions as an oxygen responsive element (ORE), maximally active at a 4% oxygen concentration. Here, we have identified three transcription factors that bind this conserved ORE, namely recombination signal sequence–binding protein J? (RBPJ), coiled-coil-helix-coiled-coil-helix domain 2 (CHCHD2) and CXXC finger protein 5 (CXXC5). We demonstrate that RBPJ and CHCHD2 function towards activating the ORE at 4% oxygen, whereas CXXC5 functions as an inhibitor. To validate results derived from cultured cells, we show using RNA interference a similar effect of these transcription factors in the gene regulation of COX4I2 in primary pulmonary arterial smooth muscle cells. Depending on the oxygen tension, a concerted action of the three transcription factors regulates the expression of COX4I2 that, as we discuss, could augment both COX activity and its ability to cope with altered cellular energy requirements.

Aras, Siddhesh; Pak, Oleg; Sommer, Natascha; Finley, Russell; Huttemann, Maik; Weissmann, Norbert; Grossman, Lawrence I.

2013-01-01

301

Genetic susceptibility for individual cooperation preferences: the role of monoamine oxidase A gene (MAOA) in the voluntary provision of public goods.  

PubMed

In the context of social dilemmas, previous research has shown that human cooperation is mainly based on the social norm of conditional cooperation. While in most cases individuals behave according to such a norm, deviant behavior is no exception. Recent research further suggests that heterogeneity in social behavior might be associated with varying genetic predispositions. In this study, we investigated the relationship between individuals' behavior in a public goods experiment and the promoter-region functional repeat polymorphism in the monoamine oxidase A gene (MAOA). In a dynamic setting of increasing information about others' contributions, we analyzed differences in two main components of conditional cooperation, namely the players' own contribution and their beliefs regarding the contribution of other players. We showed that there is a significant association between individuals' behavior in a repeated public goods game and MAOA. Our results suggest that male carriers of the low activity alleles cooperate significantly less than those carrying the high activity alleles given a situation where subjects had to rely on their innate beliefs about others' contributions. With increasing information about the others' cooperativeness, the genetic effect diminishes. Furthermore, significant opposing effects for female subjects carrying two low activity alleles were observed. PMID:21698196

Mertins, Vanessa; Schote, Andrea B; Hoffeld, Wolfgang; Griessmair, Michele; Meyer, Jobst

2011-06-16

302

Mutation T318M in the CYP11B2 gene encoding P450c11AS (aldosterone synthase) causes corticosterone methyl oxidase II deficiency.  

PubMed Central

Corticosterone methyl oxidase (CMO) deficiency refers to disorders of aldosterone synthesis due to mutations in the CYP11B2 gene encoding cytochrome P450c11AS, which is the adrenal aldosterone synthase. Type I CMO deficiency is associated with low concentrations of 18OH-corticosterone and aldosterone, due to severe mutations in P450c11AS; while type II CMO deficiency is associated with high concentrations of 18OH-corticosterone and low concentrations of aldosterone, due to less severe mutations of P450c11AS. A single type of mutation, compound homozygosity for R181W and V386A, has been reported as the cause of CMOII deficiency in an inbred population. We now report a patient with a typical clinical and hormonal picture of CMOII deficiency. Direct sequencing of patient and parent DNAs showed that the mother's allele contributed R181W and the deletion/frameshift mutation delta C372, while the father's allele contributed T318M and V386A. These mutants were recreated in cDNA expression vectors singly and in the parental pairs, showing that neither allele contributed any measurable activity. This would suggest the patient should have CMOI deficiency. These studies suggest that other factors besides P450c11AS are involved in the genesis of the distinctive CMOI and CMOII phenotypes.

Zhang, G; Rodriguez, H; Fardella, C E; Harris, D A; Miller, W L

1995-01-01

303

Genetic variation of Gongylonema pulchrum from wild animals and cattle in Japan based on ribosomal RNA and mitochondrial cytochrome c oxidase subunit I genes.  

PubMed

The gullet worm (Gongylonema pulchrum) has been recorded from a variety of mammals worldwide, including monkeys and humans. Due to its wide host range, it has been suggested that the worm may be transmitted locally to any mammalian host by chance. To investigate this notion, the ribosomal RNA gene (rDNA), mainly regions of the internal transcribed spacers (ITS) 1 and 2, and a cytochrome c oxidase subunit I (COI) region of mitochondrial DNA of G. pulchrum were characterized using parasites from the following hosts located in Japan: cattle, sika deer, wild boars, Japanese macaques, a feral Reeves's muntjac and captive squirrel monkeys. The rDNA nucleotide sequences of G. pulchrum were generally well conserved regardless of their host origin. However, a few insertions/deletions of nucleotides along with a few base substitutions in the ITS1 and ITS2 regions were observed in G. pulchrum from sika deer, wild boars and Japanese macaques, and those differed from G. pulchrum in cattle, the feral Reeves's muntjac and captive squirrel monkeys. The COI sequences of G. pulchrum were further divided into multiple haplotypes and two groups of haplotypes, i.e. those from a majority of sika deer, wild boars and Japanese macaques and those from cattle and zoo animals, were clearly differentiated. Our findings indicate that domestic and sylvatic transmission cycles of the gullet worm are currently present, at least in Japan. PMID:22967753

Makouloutou, P; Setsuda, A; Yokoyama, M; Tsuji, T; Saita, E; Torii, H; Kaneshiro, Y; Sasaki, M; Maeda, K; Une, Y; Hasegawa, H; Sato, H

2012-09-12

304

The role of an E box binding basic helix loop helix protein in the cardiac muscle-specific expression of the rat cytochrome oxidase subunit VIII gene.  

PubMed

We have characterized the rat gene for muscle-specific cytochrome oxidase VIII (COX VIII(H)) and mapped the distal promoter region responsible for transcription activation in C2C12 skeletal myocytes and H9C2 cardiomyocytes. In both cell types, the promoter elements responding to the induced differentiation of myocytes map to two E boxes, designated as E1 and E2 boxes with a core sequence of CAGCTG. Gel mobility shift analysis showed that both E1 and E2 box motifs form complexes with nuclear extracts from H9C2 cardiomyocytes that were supershifted with monoclonal antibody to E2A but not with antibody to myo-D. Extracts from induced and uninduced H9C2 cardiomyocytes yielded different gel mobility patterns and also different E2A antibody supershifts suggesting a difference in the DNA-bound protein complexes cross-reacting with the E2A antibody. Transcriptional activity of the promoter construct containing intact E boxes was inhibited by coexpression with Id in differentiated H9C2 cardiomyocytes. Our results show the involvement of an E box binding basic helix loop helix protein in the cardiac muscle-specific regulation of the COX VIII(H) promoter. PMID:8939982

Lenka, N; Basu, A; Mullick, J; Avadhani, N G

1996-11-22

305

Genetic Susceptibility for Individual Cooperation Preferences: The Role of Monoamine Oxidase A Gene (MAOA) in the Voluntary Provision of Public Goods  

PubMed Central

In the context of social dilemmas, previous research has shown that human cooperation is mainly based on the social norm of conditional cooperation. While in most cases individuals behave according to such a norm, deviant behavior is no exception. Recent research further suggests that heterogeneity in social behavior might be associated with varying genetic predispositions. In this study, we investigated the relationship between individuals' behavior in a public goods experiment and the promoter-region functional repeat polymorphism in the monoamine oxidase A gene (MAOA). In a dynamic setting of increasing information about others' contributions, we analyzed differences in two main components of conditional cooperation, namely the players' own contribution and their beliefs regarding the contribution of other players. We showed that there is a significant association between individuals' behavior in a repeated public goods game and MAOA. Our results suggest that male carriers of the low activity alleles cooperate significantly less than those carrying the high activity alleles given a situation where subjects had to rely on their innate beliefs about others' contributions. With increasing information about the others' cooperativeness, the genetic effect diminishes. Furthermore, significant opposing effects for female subjects carrying two low activity alleles were observed.

Mertins, Vanessa; Schote, Andrea B.; Hoffeld, Wolfgang; Griessmair, Michele; Meyer, Jobst

2011-01-01

306

Evidence that the methylation state of the monoamine oxidase A (MAOA) gene predicts brain activity of MAO A enzyme in healthy men.  

PubMed

Human brain function is mediated by biochemical processes, many of which can be visualized and quantified by positron emission tomography (PET). PET brain imaging of monoamine oxidase A (MAO A)-an enzyme metabolizing neurotransmitters-revealed that MAO A levels vary widely between healthy men and this variability was not explained by the common MAOA genotype (VNTR genotype), suggesting that environmental factors, through epigenetic modifications, may mediate it. Here, we analyzed MAOA methylation in white blood cells (by bisulphite conversion of genomic DNA and subsequent sequencing of cloned DNA products) and measured brain MAO A levels (using PET and [(11)C]clorgyline, a radiotracer with specificity for MAO A) in 34 healthy non-smoking male volunteers. We found significant interindividual differences in methylation status and methylation patterns of the core MAOA promoter. The VNTR genotype did not influence the methylation status of the gene or brain MAO A activity. In contrast, we found a robust association of the regional and CpG site-specific methylation of the core MAOA promoter with brain MAO A levels. These results suggest that the methylation status of the MAOA promoter (detected in white blood cells) can reliably predict the brain endophenotype. Therefore, the status of MAOA methylation observed in healthy males merits consideration as a variable contributing to interindividual differences in behavior. PMID:22948232

Shumay, Elena; Logan, Jean; Volkow, Nora D; Fowler, Joanna S

2012-09-04

307

Mutations in monoamine oxidase (MAO) genes in mice lead to hypersensitivity to serotonin-enhancing drugs: implications for drug side effects in humans.  

PubMed

A possible side effect of serotonin-enhancing drugs is the serotonin syndrome, which can be lethal. Here we examined possible hypersensitivity to two such drugs, the serotonin precursor 5-hydroxy-L-tryptophan (5-HTP) and the atypical opioid tramadol, in mice lacking the genes for both monoamine oxidase A (MAOA) and MAOB. MAOA/B-knockout (KO) mice displayed baseline serotonin syndrome behaviors, and these behavioral responses were highly exaggerated following 5-HTP or tramadol versus baseline and wild-type (WT) littermates. Compared with MAOA/B-WT mice, baseline tissue serotonin levels were increased ?2.6-3.9-fold in MAOA/B-KO mice. Following 5-HTP, serotonin levels were further increased ?4.5-6.2-fold in MAOA/B-KO mice. These exaggerated responses are in line with the exaggerated responses following serotonin-enhancing drugs that we previously observed in mice lacking the serotonin transporter (SERT). These findings provide a second genetic mouse model suggestive of possible human vulnerability to the serotonin syndrome in individuals with lesser-expressing MAO or SERT polymorphisms that confer serotonergic system changes.The Pharmacogenomics Journal advance online publication, 11 September 2012; doi:10.1038/tpj.2012.35. PMID:22964922

Fox, M A; Panessiti, M G; Moya, P R; Tolliver, T J; Chen, K; Shih, J C; Murphy, D L

2012-09-11

308

Overexpression of alternative oxidase gene confers aluminum tolerance by altering the respiratory capacity and the response to oxidative stress in tobacco cells.  

PubMed

Aluminum (Al) stress represses mitochondrial respiration and produces reactive oxygen species (ROS) in plants. Mitochondrial alternative oxidase (AOX) uncouples respiration from mitochondrial ATP production and may improve plant performance under Al stress by preventing excess accumulation of ROS. We tested respiratory changes and ROS production in isolated mitochondria and whole cell of tobacco (SL, ALT 301) under Al stress. Higher capacities of AOX pathways relative to cytochrome pathways were observed in both isolated mitochondria and whole cells of ALT301 under Al stress. AOX1 when studied showed higher AOX1 expression in ALT 301 than SL cells under stress. In order to study the function of tobacco AOX gene under Al stress, we produced transformed tobacco cell lines by introducing NtAOX1 expressed under the control of the cauliflower mosaic virus (CaMV) 35 S promoter in sensitive (SL) Nicotiana tabacum L. cell lines. The enhancement of endogenous AOX1 expression and AOX protein with or without Al stress was in the order of transformed tobacco cell lines > ALT301 > wild type (SL). A decreased respiratory inhibition and reduced ROS production with a better growth capability were the significant features that characterized AOX1 transformed cell lines under Al stress. These results demonstrated that AOX plays a critical role in Al stress tolerance with an enhanced respiratory capacity, reducing mitochondrial oxidative stress burden and improving the growth capability in tobacco cells. PMID:22965419

Panda, Sanjib Kumar; Sahoo, Lingaraj; Katsuhara, Maki; Matsumoto, Hideaki

2013-06-01

309

Rcf1 and Rcf2, Members of the Hypoxia-Induced Gene 1 Protein Family, Are Critical Components of the Mitochondrial Cytochrome bc1-Cytochrome c Oxidase Supercomplex  

PubMed Central

We report that Rcf1 (formerly Aim31), a member of the conserved hypoxia-induced gene 1 (Hig1) protein family, represents a novel component of the yeast cytochrome bc1-cytochrome c oxidase (COX) supercomplex. Rcf1 (respiratory supercomplex factor 1) partitions with the COX complex, and evidence that it may act as a bridge to the cytochrome bc1 complex is presented. Rcf1 interacts with the Cox3 subunit and can do so prior to their assembly into the COX complex. A close proximity of Rcf1 and members of the ADP/ATP carrier (AAC) family was also established. Rcf1 displays overlapping function with another Hig1-related protein, Rcf2 (formerly Aim38), and their joint presence is required for optimal COX enzyme activity and the correct assembly of the cytochrome bc1-COX supercomplex. Rcf1 and Rcf2 can independently associate with the cytochrome bc1-COX supercomplex, indicating that at least two forms of this supercomplex exist within mitochondria. We provide evidence that the association with the cytochrome bc1-COX supercomplex and regulation of the COX complex are a conserved feature of Hig1 family members. Based on our findings, we propose a model where the Hig1 proteins regulate the COX enzyme activity through Cox3 and associated Cox12 protein, in a manner that may be influenced by the neighboring AAC proteins.

Strogolova, Vera; Furness, Andrew; Robb-McGrath, Micaela; Garlich, Joshua

2012-01-01

310

Evidence that the methylation state of the monoamine oxidase A (MAOA) gene predicts brain activity of MAOA enzyme in healthy men  

PubMed Central

Human brain function is mediated by biochemical processes, many of which can be visualized and quantified by positron emission tomography (PET). PET brain imaging of monoamine oxidase A (MAOA)—an enzyme metabolizing neurotransmitters—revealed that MAOA levels vary widely between healthy men and this variability was not explained by the common MAOA genotype (VNTR genotype), suggesting that environmental factors, through epigenetic modifications, may mediate it. Here, we analyzed MAOA methylation in white blood cells (by bisulphite conversion of genomic DNA and subsequent sequencing of cloned DNA products) and measured brain MAOA levels (using PET and [11C]clorgyline, a radiotracer with specificity for MAOA) in 34 healthy non-smoking male volunteers. We found significant interindividual differences in methylation status and methylation patterns of the core MAOA promoter. The VNTR genotype did not influence the methylation status of the gene or brain MAOA activity. In contrast, we found a robust association of the regional and CpG site-specific methylation of the core MAOA promoter with brain MAOA levels. These results suggest that the methylation status of the MAOA promoter (detected in white blood cells) can reliably predict the brain endophenotype. Therefore, the status of MAOA methylation observed in healthy males merits consideration as a variable contributing to interindividual differences in behavior.

Shumay, Elena; Logan, Jean; Volkow, Nora D.; Fowler, Joanna S.

2012-01-01

311

Association of a Monoamine Oxidase-A Gene Promoter Polymorphism with ADHD and Anxiety in Boys with Autism Spectrum Disorder  

ERIC Educational Resources Information Center

|The aim of the present study was to examine the association between a variable number tandem repeat (VNTR) functional polymorphism in the promoter region of the MAO-A gene and severity of ADHD and anxiety in boys with ASD. Parents and teachers completed a DSM-IV-referenced rating scale for 5- to 14-year-old boys with ASD (n = 43). Planned…

Roohi, Jasmin; DeVincent, Carla J.; Hatchwell, Eli; Gadow, Kenneth D.

2009-01-01

312

Deletion of Genes Encoding Cytochrome Oxidases and Quinol Monooxygenase Blocks the Aerobic-Anaerobic Shift in Escherichia coli K-12 MG1655 ? †  

PubMed Central

The constitutive activation of the anoxic redox control transcriptional regulator (ArcA) in Escherichia coli during aerobic growth, with the consequent production of a strain that exhibits anaerobic physiology even in the presence of air, is reported in this work. Removal of three terminal cytochrome oxidase genes (cydAB, cyoABCD, and cbdAB) and a quinol monooxygenase gene (ygiN) from the E. coli K-12 MG1655 genome resulted in the activation of ArcA aerobically. These mutations resulted in reduction of the oxygen uptake rate by nearly 98% and production of d-lactate as a sole by-product under oxic and anoxic conditions. The knockout strain exhibited nearly identical physiological behaviors under both conditions, suggesting that the mutations resulted in significant metabolic and regulatory perturbations. In order to fully understand the physiology of this mutant and to identify underlying metabolic and regulatory reasons that prevent the transition from an aerobic to an anaerobic phenotype, we utilized whole-genome transcriptome analysis, 13C tracing experiments, and physiological characterization. Our analysis showed that the deletions resulted in the activation of anaerobic respiration under oxic conditions and a consequential shift in the content of the quinone pool from ubiquinones to menaquinones. An increase in menaquinone concentration resulted in the activation of ArcA. The activation of the ArcB/ArcA regulatory system led to a major shift in the metabolic flux distribution through the central metabolism of the mutant strain. Flux analysis indicated that the mutant strain had undetectable fluxes around the tricarboxylic acid (TCA) cycle and elevated flux through glycolysis and anaplerotic input to oxaloacetate. Flux and transcriptomics data were highly correlated and showed similar patterns.

Portnoy, Vasiliy A.; Scott, David A.; Lewis, Nathan E.; Tarasova, Yekaterina; Osterman, Andrei L.; Palsson, Bernhard ?.

2010-01-01

313

Tissue variant effects of heme inhibitors on the mouse cytochrome c oxidase gene expression and catalytic activity of the enzyme complex.  

PubMed

The in vivo effects of heme biosynthesis inhibitors, succinylacetone and CoCl2 on the cytochrome c oxidase (COX) gene expression and enzyme activity in different mouse tissues were investigated. Succinylacetone and CoCl2 showed tissue-specific differences in their ability to modulate heme aa3 content. A single dose of succinylacetone treatment for 8 h reduced the heme aa3 content of kidney mitochondria with no effect on the liver. CoCl2 treatment for 8 h, however, selectively affected the heme aa3 level in the liver. Reduced mitochondrial heme aa3 with both treatments was accompanied by approximately 50% reduced, mitochondrial genome-encoded COX I and II mRNAs and nuclear genome-encoded COX Vb mRNAs, but no change in COX IV mRNA level. Use of isolated mouse liver and brain mitochondrial systems showed a 50-80% reduction in mitochondrial transcription and translation rates in heme-depleted tissues. Blue native gel electrophoresis followed by immunoblot analysis showed that the complex from heme-depleted tissues contained a 30-50% reduction in levels of subunits I, IV, Vb and near normal levels of subunit VIc, indicating altered subunit content. Treatment of submitochondrial particles with protein kinase A and ATP resulted in partial dissociation of COX, suggesting a mechanistic basis for the reduced subunit content of the complex from heme-depleted tissues. Surprisingly, the enzyme from heme-depleted tissues showed twofold to fourfold higher turnover rates for cytochrome c oxidation, suggesting alterations in the kinetic characteristics of the enzyme following heme reduction. This is probably the first evidence that the tissue heme level regulates not only the mammalian COX gene expression, but also the catalytic activity of the enzyme, probably by affecting its stability. PMID:10542064

Vijayasarathy, C; Damle, S; Lenka, N; Avadhani, N G

1999-11-01

314

Physical linkage of the lysyl oxidase-like (LOXL1) gene to the PML gene on human chromosome 15q22  

Microsoft Academic Search

A contig was constructed centered on the PML (promyelocytic leukemia) gene. Using an exon-trapping approach to identify potential genes from a pool of cosmids located 5? of the PML gene, four exons were identified that showed 100% sequence homology with the previously cloned lysyl oxydase-like (LOXL1) gene. An exon probe identified a single transcript of 2.4 kb on a multitissue

A. Goy; F. Gilles; Y. Remache; A. D. Zelenetz

2000-01-01

315

Expression of Thiamin Biosynthetic Genes (thiCOGE) and Production of Symbiotic Terminal Oxidase cbb3 in Rhizobium etli  

Microsoft Academic Search

In this paper we report the cloning and sequence analysis of four genes, located on plasmid pb, which are involved in the synthesis of thiamin in Rhizobium etli (thiC, thiO, thiG, and thiE). Two precursors, 4-methyl- 5-(b-hydroxyethyl)thiazole monophosphate and 4-amino-5-hydroxymethylpyrimidine pyrophosphate, are cou- pled to form thiamin monophosphate, which is then phosphorylated to make thiamin pyrophosphate. The first open reading

JUAN MIRANDA-RIOS; CLAUDIA MORERA; HERMENEGILDO TABOADA; ARACELI DAVALOS; SERGIO ENCARNACION; JAIME MORA; MARIO SOBERON

1997-01-01

316

Transforming Growth Factor-? Induces Extracellular Matrix Protein Cross-Linking Lysyl Oxidase (LOX) Genes in Human Trabecular Meshwork Cells  

PubMed Central

Purpose. The profibrotic cytokine TGF? is associated with glaucoma and plays an important role in the regulation of extracellular matrix metabolism in the trabecular meshwork (TM). The purpose of this study was to determine whether expression of ECM cross-linking LOX genes is regulated by TGF? in TM cells. Methods. Expression of the five LOX genes (LOX, LOXL1, LOXL2, LOXL3, and LOXL4) was examined in cultured human TM cells by using RT-PCR, quantitative RT-PCR, and Western immunoblot analysis. TM cells were treated with recombinant TGF?1, -2, and -3, to determine the effects on LOX and LOXL1 to -4 expression. The TM cells were pretreated with TGFBR inhibitors (LY364947, SB431542), canonical Smad signaling pathway (SIS3 or Smad2, -3, and -4 siRNAs) inhibitors, or inhibitors of the non-Smad signaling pathways (SP600125, SR11302), to identify the signaling pathway(s) involved in TGF? induction of LOX and LOXL gene and protein expression. A novel LOX activity assay was used to determine the effects of the LOX inhibitor BAPN on tropoelastin cross-linking. Results. All five LOX genes (LOX, LOXL1 to -4) were expressed in cultured human TM cells and were induced by all three isoforms of TGF?. This TGF? induction of LOX and LOXL expression was blocked by TGF? inhibitors as well as by inhibitors of the canonical Smad2, -3, and -4 signaling and non-Smad JNK/AP-1 signaling pathways (P < 0.05). Conclusions. Both Smad and non-Smad signaling pathways are involved in TGF?-mediated LOX induction, suggesting complex regulation of these important extracellular matrix cross-linking enzymes. Increased LOX activity may be at least partially responsible for TGF?-mediated IOP elevation and increased aqueous humor outflow resistance.

Sethi, Anirudh; Mao, Weiming; Wordinger, Robert J.

2011-01-01

317

The Diamine Oxidase Gene Is Associated with Hypersensitivity Response to Non-Steroidal Anti-Inflammatory Drugs  

PubMed Central

Non-steroidal anti-inflammatory drugs (NSAIDs) are the drugs most frequently involved in hypersensitivity drug reactions. Histamine is released in the allergic response to NSAIDs and is responsible for some of the clinical symptoms. The aim of this study is to analyze clinical association of functional polymorphisms in the genes coding for enzymes involved in histamine homeostasis with hypersensitivity response to NSAIDs. We studied a cohort of 442 unrelated Caucasian patients with hypersensitivity to NSAIDs. Patients who experienced three or more episodes with two or more different NSAIDs were included. If this requirement was not met diagnosis was established by challenge. A total of 414 healthy unrelated controls ethnically matched with patients and from the same geographic area were recruited. Analyses of the SNPs rs17740607, rs2073440, rs1801105, rs2052129, rs10156191, rs1049742 and rs1049793 in the HDC, HNMT and DAO genes were carried out by means of TaqMan assays. The detrimental DAO 16 Met allele (rs10156191), which causes decreased metabolic capacity, is overrepresented among patients with crossed-hypersensitivity to NSAIDs with an OR ?=?1.7 (95% CI ?=?1.3–2.1; Pc ?=?0.0003) with a gene-dose effect (P?=?0.0001). The association was replicated in two populations from different geographic areas (Pc ?=?0.008 and Pc ?=?0.004, respectively). Conclusions and implications The DAO polymorphism rs10156191 which causes impaired metabolism of circulating histamine is associated with the clinical response in crossed-hypersensitivity to NSAIDs and could be used as a biomarker of response.

Agundez, Jose A. G.; Ayuso, Pedro; Cornejo-Garcia, Jose A.; Blanca, Miguel; Torres, Maria J.; Dona, Inmaculada; Salas, Maria; Blanca-Lopez, Natalia; Canto, Gabriela; Rondon, Carmen; Campo, Paloma; Laguna, Jose J.; Fernandez, Javier; Martinez, Carmen; Garcia-Martin, Elena

2012-01-01

318

Identification of regulatory elements involved in expression and induction by sucrose and UV-B light of the Arabidopsis thaliana COX5b-2 gene, encoding an isoform of cytochrome c oxidase subunit 5b.  

PubMed

The promoter sequences required for expression of the Arabidopsis thaliana COX5b-2 gene, encoding an isoform of cytochrome c oxidase subunit 5b, were analyzed using plants transformed with deleted and mutagenized forms of the promoter fused to gus. A 1000-bp promoter fragment produces expression in root and shoot meristems, leaf and cotyledon tips, and anthers. Deletion analysis indicated the presence of positive and negative regulatory elements. A regulatory element located between -660 and -620 from the translation start site was identified as a G-box by mutagenic analysis. Mutation of the G-box, that is present within the coding region of the preceding gene in the genome, increases expression of COX5b-2 in cotyledon and leaf lamina and abolishes induction by ultraviolet-B (UV-B) light, which presumably acts through the removal of an inhibitory factor. Identified positive regulatory elements include a site II element (TGGGCC), a related element with the sequence TGGGTC and four initiator elements (YTCANTYY) that completely abolish expression when mutated in combination. Site II elements are also involved in the response to sucrose. The results imply that the COX5b-2 gene has retained expression characteristics presented by most respiratory chain component genes, but its expression mechanisms have diverged from those employed by COX5b-1, the other gene encoding cytochrome c oxidase subunit 5b in Arabidopsis. PMID:19781003

Comelli, Raúl N; Gonzalez, Daniel H

2009-08-26

319

Copper Deficiency Leads to Anemia, Duodenal Hypoxia, Upregulation of HIF-2? and Altered Expression of Iron Absorption Genes in Mice  

PubMed Central

Iron and copper are essential trace metals, actively absorbed from the proximal gut in a regulated fashion. Depletion of either metal can lead to anemia. In the gut, copper deficiency can affect iron absorption through modulating the activity of hephaestin - a multi-copper oxidase required for optimal iron export from enterocytes. How systemic copper status regulates iron absorption is unknown. Mice were subjected to a nutritional copper deficiency-induced anemia regime from birth and injected with copper sulphate intraperitoneally to correct the anemia. Copper deficiency resulted in anemia, increased duodenal hypoxia and Hypoxia inducible factor 2? (HIF-2?) levels, a regulator of iron absorption. HIF-2? upregulation in copper deficiency appeared to be independent of duodenal iron or copper levels and correlated with the expression of iron transporters (Ferroportin - Fpn, Divalent Metal transporter – Dmt1) and ferric reductase – Dcytb. Alleviation of copper-dependent anemia with intraperitoneal copper injection resulted in down regulation of HIF-2?-regulated iron absorption genes in the gut. Our work identifies HIF-2? as an important regulator of iron transport machinery in copper deficiency.

Matak, Pavle; Zumerle, Sara; Mastrogiannaki, Maria; El Balkhi, Souleiman; Delga, Stephanie; Mathieu, Jacques R. R.; Canonne-Hergaux, Francois; Poupon, Joel; Sharp, Paul A.; Vaulont, Sophie; Peyssonnaux, Carole

2013-01-01

320

Enhanced expression of alternative oxidase genes is involved in the tolerance of rice (Oryza sativa L.) seedlings to drought stress.  

PubMed

Drought stress significantly enhanced the capacity of the alternative respiratory pathway and induced AOX1a and AOX1b transcripts in rice seedling leaves. The drought-stressed seedlings pretreated with the inhibitor of the alternative respiratory pathway, 1 mM salicylhydroxamic acid, had a lower level of relative water content than the seedlings either subjected to drought or salicylhydroxamic acid treatment alone. This observation suggests that the alternative respiratory pathway could play a role in the tolerance of rice seedlings to drought stress. Pretreatment with exogenous hydrogen peroxide, salicylic acid, and abscisic acid alone mitigated the water loss of rice leaves exposed to drought stress. Exogenous application of hydrogen peroxide and salicylic acid increased the capacity of the alternative respiratory pathway and induced AOX1a and AOX1b transcripts, while exogenous abscisic acid failed to induce any expression of AOX1 genes. These observations suggest that rice AOX1a and AOX1b genes may be responsive especially to drought stress but not be induced by all of the stress signals related to drought. PMID:19957440

Feng, Han-Qing; Li, Hong-Yu; Sun, Kun

321

Homocysteine induces VCAM-1 gene expression through NF-kappaB and NAD(P)H oxidase activation: protective role of Mediterranean diet polyphenolic antioxidants.  

PubMed

Hyperhomocysteinemia is a recognized risk factor for vascular disease, but pathogenetic mechanisms involved in its vascular actions are largely unknown. Because VCAM-1 expression is crucial in monocyte adhesion and early atherogenesis, we evaluated the NF-kappaB-related induction of VCAM-1 by homocysteine (Hcy) and the possible inhibitory effect of dietary polyphenolic antioxidants, such as trans-resveratrol (RSV) and hydroxytyrosol (HT), which are known inhibitors of NF-kappaB-mediated VCAM-1 induction. In human umbilical vein endothelial cells (HUVEC), Hcy, at 100 micromol/l, but not cysteine, induced VCAM-1 expression at the protein and mRNA levels, as shown by enzyme immunoassay and Northern analysis, respectively. Transfection studies with deletional VCAM-1 promoter constructs demonstrated that the two tandem NF-kappaB motifs in the VCAM-1 promoter are necessary for Hcy-induced VCAM-1 gene expression. Hcy-induced NF-kappaB activation was confirmed by EMSA, as shown by the nuclear translocation of its p65 (RelA) subunit and the degradation of the inhibitors IkappaB-alpha and IkappaB-beta by Western analysis. Hcy also increased intracellular reactive oxygen species by NAD(P)H oxidase activation, as shown by the membrane translocation of its p47(phox) subunit. NF-kappaB inhibitors decreased Hcy-induced intracellular reactive oxygen species and VCAM-1 expression. Finally, we found that nutritionally relevant concentrations of RSV and HT, but not folate and vitamin B6, reduce (by >60% at 10(-6) mol/l) Hcy-induced VCAM-1 expression and monocytoid cell adhesion to the endothelium. These data indicate that pathophysiologically relevant Hcy concentrations induce VCAM-1 expression through a prooxidant mechanism involving NF-kappaB. Natural Mediterranean diet antioxidants can inhibit such activation, suggesting their possible therapeutic role in Hcy-induced vascular damage. PMID:17586618

Carluccio, Maria Annunziata; Ancora, Maria Assunta; Massaro, Marika; Carluccio, Marisa; Scoditti, Egeria; Distante, Alessandro; Storelli, Carlo; De Caterina, Raffaele

2007-06-22

322

Gibberellin 3-oxidase Gene Expression Patterns Influence Gibberellin Biosynthesis, Growth, and Development in Pea1[W][OPEN  

PubMed Central

Gibberellins (GAs) are key modulators of plant growth and development. PsGA3ox1 (LE) encodes a GA 3?-hydroxylase that catalyzes the conversion of GA20 to biologically active GA1. To further clarify the role of GA3ox expression during pea (Pisum sativum) plant growth and development, we generated transgenic pea lines (in a lele background) with cauliflower mosaic virus-35S-driven expression of PsGA3ox1 (LE). PsGA3ox1 transgene expression led to higher GA1 concentrations in a tissue-specific and development-specific manner, altering GA biosynthesis and catabolism gene expression and plant phenotype. PsGA3ox1 transgenic plants had longer internodes, tendrils, and fruits, larger stipules, and displayed delayed flowering, increased apical meristem life, and altered vascular development relative to the null controls. Transgenic PsGA3ox1 overexpression lines were then compared with lines where endogenous PsGA3ox1 (LE) was introduced, by a series of backcrosses, into the same genetic background (BC LEle). Most notably, the BC LEle plants had substantially longer internodes containing much greater GA1 levels than the transgenic PsGA3ox1 plants. Induction of expression of the GA deactivation gene PsGA2ox1 appears to make an important contribution to limiting the increase of internode GA1 to modest levels for the transgenic lines. In contrast, PsGA3ox1 (LE) expression driven by its endogenous promoter was coordinated within the internode tissue to avoid feed-forward regulation of PsGA2ox1, resulting in much greater GA1 accumulation. These studies further our fundamental understanding of the regulation of GA biosynthesis and catabolism at the tissue and organ level and demonstrate that the timing/localization of GA3ox expression within an organ affects both GA homeostasis and GA1 levels, and thereby growth.

Reinecke, Dennis M.; Wickramarathna, Aruna D.; Ozga, Jocelyn A.; Kurepin, Leonid V.; Jin, Alena L.; Good, Allen G.; Pharis, Richard P.

2013-01-01

323

Phylogenetic position of Linguatula arctica and Linguatula serrata (Pentastomida) as inferred from the nuclear 18S rRNA gene and the mitochondrial cytochrome c oxidase subunit I gene.  

PubMed

Genomic DNA was isolated from a Linguatula serrata female expelled from a dog imported to Norway from Romania and from four Linguatula arctica females collected from semi-domesticated reindeer from northern Norway and subjected to PCR amplification of the complete nuclear 18S rRNA gene and a 1,045-bp portion of the mitochondrial cytochrome c oxidase subunit I gene (cox1). The two species differed at two of 1,830 nucleotide positions (99.9 % identity) of the complete 18S rRNA gene sequences and at 102 of 1,045 nucleotide positions (90.2 % identity) of the partial cox1 sequences. The four isolates of L. arctica showed no genetic variation in either gene. The new cox1 primers may facilitate the diagnosis of various developmental stages of L. arctica and L. serrata in their hosts. In separate phylogenetic analyses using the maximum likelihood method on sequence data from either gene, L. arctica and L. serrata clustered with members of the order Cephalobaenida rather than with members of the order Porocephalida, in which the genus Linguatula is currently placed based on morphological characters. The phylogenetic relationship of L. arctica, L. serrata and other pentastomids to other metazoan groups could not be clearly resolved, but the pentastomids did not seem to have a sister relationship to crustaceans of the subclass Branchiura as found in other studies. A more extensive taxon sampling, including molecular characterisation of more pentastomid taxa across different genera, seems to be necessary in order to estimate the true relationship of the Pentastomida to other metazoan groups. PMID:23873617

Gjerde, Bjørn

2013-07-20

324

Oxidases and related redox systems  

SciTech Connect

This book contains the proceedings of a symposium on oxidases and related redoxsystems. Topics covered include: Oxidases and related redoxsystems, Flavoprotein oxidases and oxygenases, Peroxidases, and Cytochrome P-450 and related proteins.

King, T.E. (Inst. for Structural and Functional Studies, Univ. City Science Center, Philadelphia, PA (US)); Mason, H.S. (Dept. of Biochemistry, Oregon Health Sciences Univ., Portland, OR (US)); Morrison, M. (Saint Jude Children's Hospital, Memphis, TN (USA). Dept. of Biochemical and Chemical Pharmacology)

1988-01-01

325

Expression of Pisum sativum PsAO3 gene, which encodes an aldehyde oxidase utilizing abscisic aldehyde, is induced under progressively but not rapidly imposed drought stress.  

PubMed

Aldehyde oxidase (AO; EC 1.2.3.1) catalyzes the final step of abscisic acid (ABA) biosynthesis, which is the oxidation of abscisic aldehyde (ABAld) to ABA. Gene expression analyses indicate that the stress-induced Pisum sativum PsAO? isoform, which effectively uses ABAld as a substrate, is encoded by the PsAO3 gene. PsAO3 was heterologously expressed in Pichia pastoris and the recombinant PsAO3 protein revealed substrate preferences highly similar to the native PsAO? protein present in the pea leaves and roots. Both proteins prefer indole-3-aldehyde and naphthaldehyde as substrates, although high activities against abscisic aldehyde and citral were also observed. The Km values of PsAO3 for naphthaldehyde and abscisic aldehyde (4.6 and 5.1 ?M, respectively) were the lowest among the substrates tested. PsAO3 activity was almost completely inhibited by potassium cyanide, diphenyleneiodonium, and methanol. Rapidly imposed drought stress did not increase the level of PsAO3 mRNA or activity of any AO isoform, although an enhanced ABA accumulation and induction of PsNCED2 and -3 (9-cis-epoxycarotenoid dioxygenase; EC 1.13.11.51) expression, both in the pea roots and leaves, was observed. During a progressively induced drought, the level of PsAO3 transcript and PsAO? activity increased significantly in the roots and leaves, whereas ABA accumulation occurred only in the leaves where it was accompanied by induction of the PsNCED3 expression. Therefore, we suppose that next to NCED, also AO (mainly PsAO?) might be involved in regulation of the drought-induced ABA synthesis. However, while the "constitutive activity" of PsAO? is sufficient for the fast generation of ABA under rapid drought stress, the enhanced PsAO? activity is required for the progressive and long-term ABA accumulation in the leaves under progressive drought stress. PMID:23876699

Zdunek-Zastocka, Edyta; Sobczak, Miros?aw

2013-07-06

326

Molecular relationships and classification of several tufted capuchin lineages (Cebus apella, Cebus xanthosternos and Cebus nigritus, Cebidae), by means of mitochondrial cytochrome oxidase II gene sequences.  

PubMed

The morphological systematics of the tufted capuchins is confusing. In an attempt to clarify the complex systematics and phylogeography of this taxon, we provide a first molecular analysis. We obtained mitochondrial cytochrome oxidase II (mtCOII) gene sequences from 49 tufted capuchins that had exact geographic origins from diverse lineages in Colombia, Peru, Bolivia, French Guyana, Brazil, Argentina and Paraguay and that belonged to clearly recognized morphological taxa. This project had 4 main findings: (1) we determined 2 established and related taxa in the northern Amazon River area, which we named C. a. apella and C. a. fatuellus. C. a. apella is distributed from French Guyana until, at least, the Negro River in the northern Brazilian Amazon, whereas C. a. fatuellus is distributed throughout the Colombian Eastern Llanos and the northern Colombian Amazon. We also determined 2 other southern C. apella taxa, which we named C. a. macrodon and C. a. cay. C. a. macrodon has a western and southern Amazon distribution, while C. a. cay has a more southern distribution outside the Amazon basin. (2) In the upper Amazon basin, there is a unique lineage (C. a. macrocephalus) with 1 widely distributed haplotype. The 4 morphological subspecies (C. a. maranonis, C. a. macrocephalus, C. a. peruanus, C. a. pallidus), and maybe a fifth unknown subspecies, described in this area were molecularly undifferentiated at least for the mitochondrial gene analyzed. (3) Our molecular analysis determined that 1 individual of C. robustus fell into the lineage of C. a. macrocephalus. Therefore, this form does not receive any specific name. (4) The animals classified a priori as C. nigritus and C. xanthosternos (because of their morphological phenotypes and by their geographical origins) were clearly differentiated from the other specimens analyzed with the molecular marker employed. Therefore, we consider that these 2 lineages could be assigned the status of full species following the biological species definition. (5) In 2001, Groves described 4 tufted capuchin species (C. apella, C. libidinosus, C. nigritus and C. xanthosternos), while Silva Jr. determined 7 species (C. apella, C. macrocephalus, C. libidinosus, C. cay, C. nigritus, C. robustus and C. xanthosternos). The tests of Swofford-Olsen-Waddell-Hillis, of Shimodaira and Hasegawa and of Templeton did not fit with either of these two classificatory schemes, although Groves' scheme was better with regard to our data than that of Silva Jr. (6) All the temporal splits among the tufted capuchin taxa studied were estimated to have occurred during the last phase of the Pleistocene by using the ? statistic applied to the median joining haplotype network. PMID:23128150

Ruiz-García, Manuel; Castillo, Maria Ignacia; Lichilín-Ortiz, Nicolás; Pinedo-Castro, Myreya

2012-10-30

327

PPAR? and Proline Oxidase in Cancer  

PubMed Central

Proline is metabolized by its own specialized enzymes with their own tissue and subcellular localizations and mechanisms of regulation. The central enzyme in this metabolic system is proline oxidase, a flavin adenine dinucleotide-containing enzyme which is tightly bound to mitochondrial inner membranes. The electrons from proline can be used to generate ATP or can directly reduce oxygen to form superoxide. Although proline may be derived from the diet and biosynthesized endogenously, an important source in the microenvironment is from degradation of extracellular matrix by matrix metalloproteinases. Previous studies showed that proline oxidase is a p53-induced gene and its overexpression can initiate proline-dependent apoptosis by both intrinsic and extrinsic pathways. Another important factor regulating proline oxidase is peroxisome proliferator activated receptor gamma (PPAR?). Importantly, in several cancer cells, proline oxidase may be an important mediator of the PPAR?-stimulated generation of ROS and induction of apoptosis. Knockdown of proline oxidase expression by antisense RNA markedly decreased these PPAR?-stimulated effects. These findings suggest an important role in the proposed antitumor effects of PPAR?. Moreover, it is possible that proline oxidase may contribute to the other metabolic effects of PPAR?.

Phang, James M.; Pandhare, Jui; Zabirnyk, Olga; Liu, Yongmin

2008-01-01

328

Mitochondrial Cytochrome c Oxidase and F1Fo-ATPase Dysfunction in Peppers (Capsicum annuum L.) with Cytoplasmic Male Sterility and Its Association with orf507 and ?atp6-2 Genes  

PubMed Central

Cytoplasmic male sterility (CMS) in pepper (Capsicum annuum L.) has been associated with novel genes in the mitochondria, such as orf507 and ?atp6-2. Plant sterility has been proved to result from the rearrangement of the mitochondrial genome. Previous studies have demonstrated that orf507 is co-transcribed with the cox II gene, and ?atp6-2 is truncated at the 3? region of the atp6-2 that is found in the maintainer line. Until this time, little has been known about the relationship between the novel gene and the function of its corresponding enzyme in mitochondria from the CMS pepper line. Moreover, the aberrant function of the mitochondrial enzymes is seldom reported in pepper. In this study, we observed that anther abortion occurred after the tetrad stage in the CMS line (HW203A), which was accompanied by premature programmed cell death (PCD) in the tapetum. The spatiotemporal expression patterns of orf507 and ?atp6-2 were analyzed together with the corresponding enzyme activities to investigate the interactions of the genes and mitochondrial enzymes. The two genes were both highly expressed in the anther. The orf507 was down-regulated in HW203A (CMS line), with nearly no expression in HW203B (the maintainer line). In contrast, the cytochrome c oxidase activity in HW203A showed the opposite trend, reaching its highest peak at the tetrad stage when compared with HW203B at the same stage. The ?atp6-2 in the CMS line was also down-regulated, but it was up-regulated in the maintainer line. The corresponding F1Fo-ATPase activity in the CMS line was gradually decreased along with the development of the anther, which showed the same trend for ?atp6-2 gene expression. On the contrary, with up-regulated gene expression of atp6-2 in the maintainer line, the F1Fo-ATPase activity sharply decreased after the initial development stage, but gradually increased following the tetrad stage, which was contrary to what happened in the CMS line. Taken together, all these results may provide evidence for the involvement of aberrant mitochondrial cytochrome c oxidase and F1Fo-ATPase in CMS pepper anther abortion. Moreover, the novel orf507 and ?atp6-2 genes in the mitochondria may be involved in the dysfunction of the cytochrome c oxidase and F1Fo-ATPase, respectively, which are responsible for the abortion of anthers in the CMS line.

Ji, Jiaojiao; Huang, Wei; Yin, Chuanchuan; Gong, Zhenhui

2013-01-01

329

Mitochondrial Cytochrome c Oxidase and F1Fo-ATPase Dysfunction in Peppers (Capsicum annuum L.) with Cytoplasmic Male Sterility and Its Association with orf507 and ?atp6-2 Genes.  

PubMed

Cytoplasmic male sterility (CMS) in pepper (Capsicum annuum L.) has been associated with novel genes in the mitochondria, such as orf507 and ?atp6-2. Plant sterility has been proved to result from the rearrangement of the mitochondrial genome. Previous studies have demonstrated that orf507 is co-transcribed with the cox II gene, and ?atp6-2 is truncated at the 3' region of the atp6-2 that is found in the maintainer line. Until this time, little has been known about the relationship between the novel gene and the function of its corresponding enzyme in mitochondria from the CMS pepper line. Moreover, the aberrant function of the mitochondrial enzymes is seldom reported in pepper. In this study, we observed that anther abortion occurred after the tetrad stage in the CMS line (HW203A), which was accompanied by premature programmed cell death (PCD) in the tapetum. The spatiotemporal expression patterns of orf507 and ?atp6-2 were analyzed together with the corresponding enzyme activities to investigate the interactions of the genes and mitochondrial enzymes. The two genes were both highly expressed in the anther. The orf507 was down-regulated in HW203A (CMS line), with nearly no expression in HW203B (the maintainer line). In contrast, the cytochrome c oxidase activity in HW203A showed the opposite trend, reaching its highest peak at the tetrad stage when compared with HW203B at the same stage. The ?atp6-2 in the CMS line was also down-regulated, but it was up-regulated in the maintainer line. The corresponding F(1)F(o)-ATPase activity in the CMS line was gradually decreased along with the development of the anther, which showed the same trend for ?atp6-2 gene expression. On the contrary, with up-regulated gene expression of atp6-2 in the maintainer line, the F(1)F(o)-ATPase activity sharply decreased after the initial development stage, but gradually increased following the tetrad stage, which was contrary to what happened in the CMS line. Taken together, all these results may provide evidence for the involvement of aberrant mitochondrial cytochrome c oxidase and F(1)F(o)-ATPase in CMS pepper anther abortion. Moreover, the novel orf507 and ?atp6-2 genes in the mitochondria may be involved in the dysfunction of the cytochrome c oxidase and F(1)F(o)-ATPase, respectively, which are responsible for the abortion of anthers in the CMS line. PMID:23296278

Ji, Jiaojiao; Huang, Wei; Yin, Chuanchuan; Gong, Zhenhui

2013-01-07

330

A Diphenol Oxidase Gene Is Part of a Cluster of Genes Involved in Catecholamine Metabolism and Sclerotization in Drosophila. II. Molecular Localization of the Dox-A2 Coding Region  

PubMed Central

Mutations at the Dox-A2 (2-53.9) locus alter the A2 component of diphenol oxidase, an enzyme having an important role in cuticle formation. This locus is in the dopa decarboxylase, Df( 2L)TW130 region, which contains a cluster of at least 14 genes involved in catecholamine metabolism and the formation, sclerotization and melanization of cuticle in Drosophila. The region is subdivided by deficiencies, and localization of breakpoints in cloned DNA reveals a dense subcluster of six genes in the 23 kb proximal to Ddc. Five lethal loci distal to Ddc comprise a second such subcluster. The proximal breakpoints of deficiencies Df(2L)hk18 and Df(2L)OD15 define a 14.3- to 16.8-kb region containing Dox-A2 and l(2 )37Bb, and those of Df(2L)OD15 and Df(2L)TW203 define a 9.3- to 12.1-kb region containing l(2)37Ba, l(2)37Bc and l( 2)37Be.—Southern blots show two of the Dox-A2 mutations are small deletions (0.1 and 1.1 kb). The Dox-A2 locus mRNA is 1.7 kb. cDNA clones indicate that the 3' end is centromere proximal and that the coding region contains at least one small intron. The Dox-A2 locus is within 3.4 to 4.4 kb of the Df(2L)OD15 breakpoint, placing four of the vital loci within a maximum of 15.5 kb. The location of Dox-A2 in a cluster of genes affecting cuticle formation is discussed.

Pentz, Ellen Steward; Wright, Theodore R. F.

1986-01-01

331

Coniferyl alcohol oxidase — a catechol oxidase?  

Microsoft Academic Search

The physico-chemical properties of coniferyl alcohol oxidase (CAO), a copper containing glycoprotein spatiotemporally associated with lignification in conifers, is reported here. By electron paramagnetic resonance spectroscopy, only type 3 copper was indicated in CAO. CAO oxidizes several laccase substrates; however, it is not a blue-copper protein and monoclonal antibodies against both native and deglycosylated CAO did not recognize any of

Preethi V. Udagama-Randeniya; Rodney A. Savidge

1995-01-01

332

Cytochrome oxidase in health and disease  

Microsoft Academic Search

Yeast and bovine cytochrome c oxidases (COX) are composed of 12 and 13 different polypeptides, respectively. In both cases, the three subunits constituting the catalytic core are encoded by mitochondrial DNA. The other subunits are all products of nuclear genes that are translated on cytoplasmic ribosomes and imported through different transport routes into mitochondria. Biogenesis of the functional complex depends

Antoni Barrientos; Mario H. Barros; Isabelle Valnot; Agnes Rötig; Pierre Rustin; Alexander Tzagoloff

2002-01-01

333

Function and Expression Analysis of Gibberellin Oxidases in Apple  

Microsoft Academic Search

Three cDNAs, encoding gibberellin (GA) 20-oxidase (MdGA20ox1, identical to AB037114), 3-oxidase (MdGA3ox1), and 2-oxidase (MdGA2ox1), were isolated from apple cv. Fuji (Malus x domestica). Southern blot analysis indicated that each of these genes belongs to a gene family. Standard enzyme assays show that the\\u000a MdGA20ox1-MBP fusion protein can sequentially oxidize three times at C-20 position of GA12 and GA53 and

Huijun Zhao; Jiangli Dong; Tao Wang

2010-01-01

334

Regulation of murine cytochrome c oxidase Vb gene expression during myogenesis: YY-1 and heterogeneous nuclear ribonucleoprotein D-like protein (JKTBP1) reciprocally regulate transcription activity by physical interaction with the BERF-1/ZBP-89 factor.  

PubMed

A transcription suppressor element (sequence -481 to -320) containing a G-rich motif (designated GTG) and a newly identified CAT-rich motif (designated CATR) was previously shown to modulate expression of the mouse cytochrome c oxidase Vb gene during myogenesis. Here, we show that the GTG element is critical for transcription activation in both undifferentiated and differentiated myocytes. Mutations of the CATR motif abolished transcription repression in myoblasts while limiting transcription activation in differentiated myotubes, suggesting contrasting functional attributes of this DNA motif at different stages of myogenesis. Results show that the activity of the transcription suppressor motif is modulated by an orchestrated interplay between ubiquitous transcription factors: ZBP-89, YY-1, and a member of the heterogeneous nuclear ribonucleoprotein D-like protein (also known as JKTBP1) family. In undifferentiated muscle cells, GTG motif-bound ZBP-89 physically and functionally interacted with CATR motif-bound YY-1 to mediate transcription repression. In differentiated myotubes, heterogeneous nuclear ribonucleoprotein D-like protein/JKTBP1 bound to the CATR motif exclusive of YY-1 and interacted with ZBP-89 in attenuating repressor activity, leading to transcription activation. Our results show a novel mechanism of protein factor switching in transcription regulation of the cytochrome c oxidase Vb gene during myogenesis. PMID:15190078

Boopathi, Ettickan; Lenka, Nibedita; Prabu, Subbuswamy K; Fang, Ji-Kang; Wilkinson, Frank; Atchison, Michael; Giallongo, Agata; Avadhani, Narayan G

2004-06-09

335

Tyrosinase and Catechol Oxidase  

Microsoft Academic Search

THE nature of tyrosinase has been under discussion for a very long time. Raper and his school1, Graubard and Nelson2, and Keilin and Mann3 believe it to be a distinct enzyme, different from catechol oxidase. Onslow and Robinson4, McCance5, and Richter6 believe it to be a catechol oxidase plus o-chinone plus dehydrogenase. Kubowitz7, whose work appeared in a recent issue

L. Califano; D. Kertesz

1938-01-01

336

A novel proteolytic processing of prolysyl oxidase.  

PubMed

Lysyl oxidase (LOX) is an amine oxidase that is critical for the stability of connective tissues. The secreted proLOX is enzymatically quiescent and is activated through proteolytic cleavage between residues Gly(162) and Asp(163) (residue numbers according to the mouse LOX) by bone morphogenetic protein (BMP)-1 gene products. Here we report a novel processing of proLOX identified in vitro and in vivo. Two forms of mature LOX were identified and characterized by their immunoreactivity to specific antibodies, amine oxidase activity, and mass spectrometry. One form was identified as a well-characterized BMP-1 processed LOX protein. Another was found to be a truncated form of LOX resulting from the cleavage at the carboxy terminus of Arg(192). The truncated form of LOX still appeared to retain amine oxidase activity. The results from the proLOX gene deletion and mutation experiments indicated that the processing occurs independent of the cleavage of proLOX by BMP-1 gene products and likely requires the presence of LOX propeptide. These results indicate that proLOX could be processed by two different mechanisms producing two forms of active LOX. PMID:21591931

Atsawasuwan, Phimon; Mochida, Yoshiyuki; Katafuchi, Michitsuna; Tokutomi, Kentaro; Mocanu, Viorel; Parker, Carol E; Yamauchi, Mitsuo

2011-05-18

337

A novel proteolytic processing of prolysyl oxidase  

PubMed Central

Lysyl oxidase (LOX) is an amine oxidase that is critical for the stability of connective tissues. The secreted proLOX is enzymatically quiescent and is activated through proteolytic cleavage between residue Gly162 and Asp163 (residue numbers according to the mouse LOX) by bone morphogenetic protein (BMP)-1 gene products. Here we report a novel processing of proLOX identified in vitro and in vivo. Two forms of mature LOX were identified and characterized by their immunoreactivity to specific antibodies, amine oxidase activity and mass spectrometry. One form was identified as a well characterized BMP-1 processed LOX protein. Another was found to be a truncated form of LOX (tLOX) resulting from the cleavage at the carboxy terminus of Arg192. The tLOX still appeared to retain amine oxidase activity. The results from the proLOX gene deletion and mutation experiments indicated that the processing occurs independent of the cleavage of proLOX by BMP-1 gene products and likely requires the presence of LOX propeptide. These results indicate that proLOX could be processed by two different mechanisms producing two forms of active LOX.

Atsawasuwan, Phimon; Mochida, Yoshiyuki; Katafuchi, Michitsuna; Tokutomi, Kentaro; Mocanu, Viorel; Parker, Carol E.; Yamauchi, Mitsuo

2012-01-01

338

Azorhizobium caulinodans respires with at least four terminal oxidases.  

PubMed Central

In culture, Azorhizobium caulinodans used at least four terminal oxidases, cytochrome aa3 (cytaa3), cytd, cyto, and a second a-type cytochrome, which together mediated general, respiratory electron (e-) transport to O2. To genetically dissect physiological roles for these various terminal oxidases, corresponding Azorhizobium apocytochrome genes were cloned, and three cytaa3 mutants, a cytd mutant, and a cytaa3, cytd double mutant were constructed by reverse genetics. These cytochrome oxidase mutants were tested for growth, oxidase activities, and N2 fixation properties both in culture and in symbiosis with the host plant Sesbania rostrata. The cytaa3 mutants grew normally, fixed N2 normally, and remained fully able to oxidize general respiratory e- donors (NADH, succinate) which utilize a cytc-dependent oxidase. By difference spectroscopy, a second, a-type cytochrome was detected in the cytaa3 mutants. This alternative a-type cytochrome (Amax = 610 nm) was also present in the wild type but was masked by bona fide cytaa3 (Amax = 605 nm). In late exponential-phase cultures, the cytaa3 mutants induced a new, membrane-bound, CO-binding cytc550, which also might serve as a cytc oxidase (a fifth terminal oxidase). The cloned Azorhizobium cytaa3 genes were strongly expressed during exponential growth but were deactivated prior to onset of stationary phase. Azorhizobium cytd mutants showed 40% lower N2 fixation rates in culture and in planta, but aerobic growth rates were wild type. The cytaa3, cytd double mutant showed 70% lower N2 fixation rates in planta. Pleiotropic cytc mutants were isolated by screening for strains unable to use N,N,N',N'-tetramethyl-p-phenylenediamine as a respiratory e- donor. These mutants synthesized no detectable cytc, excreted coproporphyrin, grew normally in aerobic minimal medium, grew poorly in rich medium, and fixed N2 poorly both in culture and in planta. Therefore, while aerobic growth was sustained by quinol oxidases alone, N2 fixation required cytc oxidase activities. Assuming that the terminal oxidases function as do their homologs in other bacteria, Azorhizobium respiration simultaneously employs both quinol and cytc oxidases. Because Azorhizobium terminal oxidase mutants were able to reformulate their terminal oxidase mix and grow more or less normally in aerobic culture, these terminal oxidases are somewhat degenerate. Its extensive terminal oxidase repertoire might allow Azorhizobium spp. to flourish in wide-ranging O2 environments. Images

Kitts, C L; Ludwig, R A

1994-01-01

339

Gene isolation and characterization of two acyl CoA oxidases from soybean with broad substrate specificities and enhanced expression in the growing seedling axis  

Microsoft Academic Search

The first committed step in the ß-oxidation of fatty acids is catalyzed by the enzyme acyl-CoA oxidase (ACOX), which oxidizes a fatty acyl-CoA to a 2-trans-enoyl-CoA. To understand the role of ß-oxidation during seedling growth in soybean, two ACOX cDNAs were isolated by screening a seedling library with a DNA fragment obtained by RT-PCR by using degenerate oligonucleotides. The two

Ameeta K. Agarwal; Youlin Qi; Deepti G. Bhat; B. Mark Woerner; Sherri M. Brown

2001-01-01

340

Enhanced de novo shoot morphogenesis in vitro by expression of antisense 1-aminocyclopropane-1-carboxylate oxidase gene in transgenic mustard plants  

Microsoft Academic Search

The role of ethylene in shoot morphogenesis in vitro was investigated via the production of transgenic mustard (Brassica juncea (L.) Czern & Coss cv. Indian Mustard) plants with impaired ethylene biosynthesis using the antisense-RNA approach. Mustard plants transformed with antisense MEFE5 encoding 1-aminocyclo propane-1-carboxylate (ACC) oxidase, which catalyses the conversion of ACC to ethylene in mustard, were characterized with respect

Eng-Chong Pua; Justin E. E. Lee

1995-01-01

341

Differential induction of stearoyl-CoA desaturase and acyl-CoA oxidase genes by fibrates in HepG2 cells  

Microsoft Academic Search

1We studied whether two typical effects of fibrates, induction of stearoyl-CoA desaturase (EC 1.14.99.5) and peroxisome proliferation, are related. The effect of bezafibrate on the activity and mRNA of stearoyl-CoA desaturase and acyl-CoA oxidase in the liver and epididymal white adipose tissue of male Sprague–Dawley rats was determined. The same parameters were measured in HepG2 cells, a cell line resistant

Cristina Rodr??guez; Agatha Cabrero; Núria Roglans; Tomás Adzet; Rosa M. Sánchez; Manuel Vázquez; Carlos J. Ciudad; Juan C. Laguna

2001-01-01

342

Identification of a Gene for Pyruvate-Insensitive Mitochondrial Alternative Oxidase Expressed in the Thermogenic Appendices in Arum maculatum1[W][OA  

PubMed Central

Heat production in thermogenic plants has been attributed to a large increase in the expression of the alternative oxidase (AOX). AOX acts as an alternative terminal oxidase in the mitochondrial respiratory chain, where it reduces molecular oxygen to water. In contrast to the mitochondrial terminal oxidase, cytochrome c oxidase, AOX is nonprotonmotive and thus allows the dramatic drop in free energy between ubiquinol and oxygen to be dissipated as heat. Using reverse transcription-polymerase chain reaction-based cloning, we reveal that, although at least seven cDNAs for AOX exist (AmAOX1a, -1b, -1c, -1d, -1e, -1f, and -1g) in Arum maculatum, the organ and developmental regulation for each is distinct. In particular, the expression of AmAOX1e transcripts appears to predominate in thermogenic appendices among the seven AmAOXs. Interestingly, the amino acid sequence of AmAOX1e indicates that the ENV element found in almost all other AOX sequences, including AmAOX1a, -1b, -1c, -1d, and -1f, is substituted by QNT. The existence of a QNT motif in AmAOX1e was confirmed by nano-liquid chromatography-tandem mass spectrometry analysis of mitochondrial proteins from thermogenic appendices. Further functional analyses with mitochondria prepared using a yeast heterologous expression system demonstrated that AmAOX1e is insensitive to stimulation by pyruvate. These data suggest that a QNT type of pyruvate-insensitive AOX, AmAOX1e, plays a crucial role in stage- and organ-specific heat production in the appendices of A. maculatum.

Ito, Kikukatsu; Ogata, Takafumi; Kakizaki, Yusuke; Elliott, Catherine; Albury, Mary S.; Moore, Anthony L.

2011-01-01

343

The alternative oxidase (AOX) gene in Vibrio fischeri is controlled by NsrR and upregulated in response to nitric oxide  

PubMed Central

Summary Alternative oxidase (AOX) is a respiratory oxidase found in certain eukaryotes and bacteria; however, its role in bacterial physiology is unclear. Exploiting the genetic tractability of the bacterium Vibrio fischeri, we explore the regulation of aox expression and AOX function. Using quantitative PCR and reporter assays, we demonstrate that aox expression is induced in the presence of nitric oxide (NO), and that the NO-responsive regulatory protein NsrR mediates the response. We have identified key amino acid residues important for NsrR function and experimentally confirmed a bioinformatically predicted NsrR binding site upstream of aox. Microrespirometry demonstrated that oxygen consumption by V. fischeri CydAB quinol oxidase is inhibited by NO treatment, whereas oxygen consumption by AOX is less sensitive to NO. NADH oxidation assays using inverted membrane vesicles confirmed that NO directly inhibits CydAB, and that AOX is resistant to NO inhibition. These results indicate a role for V. fischeri AOX in aerobic respiration during NO stress.

Dunn, Anne K.; Karr, Elizabeth A.; Wang, Yanling; Batton, Aaron R.; Ruby, Edward G.; Stabb, Eric V.

2013-01-01

344

Prokaryotic orthologues of mitochondrial alternative oxidase and plastid terminal oxidase  

Microsoft Academic Search

The mitochondrial alternative oxidase (AOX) and the plastid terminal oxidase (PTOX) are two similar members of the membrane-bound diiron carboxylate group of proteins. AOX is a ubiquinol oxidase present in all higher plants, as well as some algae, fungi, and protists. It may serve to dampen reactive oxygen species generation by the respiratory electron transport chain. PTOX is a plastoquinol

Allison E. McDonald; Sasan Amirsadeghi; Greg C. Vanlerberghe

2003-01-01

345

The structure and inhibition of human diamine oxidase†,‡  

PubMed Central

Humans have three functioning genes that code for copper-containing amine oxidases. The product of the AOC1 gene is a so-called diamine oxidase (hDAO), named for its substrate preference for diamines, particularly histamine. hDAO has been cloned and expressed in insect cells and the structure of the native enzyme determined by X-ray crystallography to a resolution of 1.8 Å. The homodimeric structure has the archetypal amine oxidase fold. Two active sites, one in each subunit, are characterized by the presence of a copper ion and a topaquinone residue formed by the post-translational modification of a tyrosine. Although hDAO shares 37.9 % sequence identity with another human copper amine oxidase, semicarbazide sensitive amine oxidase or vascular adhesion protein-1, its substrate binding pocket and entry channel are distinctly different in accord with the different substrate specificities. The structures of two inhibitor complexes of hDAO, berenil and pentamidine, have been refined to resolutions of 2.1 Å and 2.2 Å, respectively. They bind non-covalently in the active site channel. The inhibitor binding suggests that an aspartic acid residue, conserved in all diamine oxidases but absent from other amine oxidases, is responsible for the diamine specificity by interacting with the second amino group of preferred diamine substrates.

McGrath, Aaron P; Hilmer, Kimberly M; Collyer, Charles A; Shepard, Eric M; Elmore, Bradley O.; Brown, Doreen E; Dooley, David M; Guss, J Mitchell

2009-01-01

346

Inventory control: cytochrome c oxidase assembly regulates mitochondrial translation.  

PubMed

Mitochondria maintain genome and translation machinery to synthesize a small subset of subunits of the oxidative phosphorylation system. To build up functional enzymes, these organellar gene products must assemble with imported subunits that are encoded in the nucleus. New findings on the early steps of cytochrome c oxidase assembly reveal how the mitochondrial translation of its core component, cytochrome c oxidase subunit 1 (Cox1), is directly coupled to the assembly of this respiratory complex. PMID:21179059

Mick, David U; Fox, Thomas D; Rehling, Peter

2011-01-01

347

CHARACTERISTICS OF POLYPHENOL OXIDASES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Polyphenol oxidase (PPO, EC 1.14.18.1 or EC 1.10.3.1) catalyzes the oxidation of o-diphenols to o-quinones. Highly reactive o-quinones couple with phenolics and specific amino acids on proteins to form the characteristic browning products in many wounded fruits, vegetables, and leaf tissues of plant...

348

Adipogenesis-related increase of semicarbazide-sensitive amine oxidase and monoamine oxidase in human adipocytes.  

PubMed

A strong induction of semicarbazide-sensitive amine oxidase (SSAO) has previously been reported during murine preadipocyte lineage differentiation but it remains unknown whether this emergence also occurs during adipogenesis in man. Our aim was to compare SSAO and monoamine oxidase (MAO) expression during in vitro differentiation of human preadipocytes and in adipose and stroma-vascular fractions of human fat depots. A human preadipocyte cell strain from a patient with Simpson-Golabi-Behmel syndrome was first used to follow amine oxidase expression during in vitro differentiation. Then, human preadipocytes isolated from subcutaneous adipose tissues were cultured under conditions promoting ex vivo adipose differentiation and tested for MAO and SSAO expression. Lastly, human adipose tissue was separated into mature adipocyte and stroma-vascular fractions for analyses of MAO and SSAO at mRNA, protein and activity levels. Both SSAO and MAO were increased from undifferentiated preadipocytes to lipid-laden cells in all the models: 3T3-F442A and 3T3-L1 murine lineages, human SGBS cell strain or human preadipocytes in primary culture. In human subcutaneous adipose tissue, the adipocyte-enriched fraction exhibited seven-fold higher amine oxidase activity and contained three- to seven-fold higher levels of mRNAs encoded by MAO-A, MAO-B, AOC3 and AOC2 genes than the stroma-vascular fraction. MAO-A and AOC3 genes accounted for the majority of their respective MAO and SSAO activities in human adipose tissue. Most of the SSAO and MAO found in adipose tissue originated from mature adipocytes. Although the mechanism and role of adipogenesis-related increase in amine oxidase expression remain to be established, the resulting elevated levels of amine oxidase activities found in human adipocytes may be of potential interest for therapeutic intervention in obesity. PMID:17400359

Bour, Sandy; Daviaud, Danièle; Gres, Sandra; Lefort, Corinne; Prévot, Danielle; Zorzano, Antonio; Wabitsch, Martin; Saulnier-Blache, Jean-Sébastien; Valet, Philippe; Carpéné, Christian

2007-02-24

349

Ethylene Synthesis Regulated by Biphasic Induction of 1-Aminocyclopropane-1-Carboxylic Acid Synthase and 1-Aminocyclopropane-1-Carboxylic Acid Oxidase Genes Is Required for Hydrogen Peroxide Accumulation and Cell Death in Ozone-Exposed Tomato1  

PubMed Central

We show that above a certain threshold concentration, ozone leads to leaf injury in tomato (Lycopersicon esculentum). Ozone-induced leaf damage was preceded by a rapid increase in 1-aminocyclopropane-1-carboxylic acid (ACC) synthase activity, ACC content, and ethylene emission. Changes in mRNA levels of specific ACC synthase, ACC oxidase, and ethylene receptor genes occurred within 1 to 5 h. Expression of the genes encoding components of ethylene biosynthesis and perception, and biochemistry of ethylene synthesis suggested that ozone-induced ethylene synthesis in tomato is under biphasic control. In transgenic plants containing an LE-ACO1 promoter-?-glucuronidase fusion construct, ?-glucuronidase activity increased rapidly at the beginning of the O3 exposure and had a spatial distribution resembling the pattern of extracellular H2O2 production at 7 h, which coincided with the cell death pattern after 24 h. Ethylene synthesis and perception were required for active H2O2 production and cell death resulting in visible tissue damage. The results demonstrate a selective ozone response of ethylene biosynthetic genes and suggest a role for ethylene, in combination with the burst of H2O2 production, in regulating the spread of cell death.

Moeder, Wolfgang; Barry, Cornelius S.; Tauriainen, Airi A.; Betz, Christian; Tuomainen, Jaana; Utriainen, Merja; Grierson, Donald; Sandermann, Heinrich; Langebartels, Christian; Kangasjarvi, Jaakko

2002-01-01

350

NADPH oxidase 4 regulates cardiomyocyte differentiation via redox activation of c-Jun protein and the cis-regulation of GATA-4 gene transcription.  

PubMed

NADPH oxidase 4 (Nox4) generates reactive oxygen species (ROS) that can modulate cellular phenotype and function in part through the redox modulation of the activity of transcription factors. We demonstrate here the potential of Nox4 to drive cardiomyocyte differentiation in pluripotent embryonal carcinoma cells, and we show that this involves the redox activation of c-Jun. This in turn acts to up-regulate GATA-4 expression, one of the earliest markers of cardiotypic differentiation, through a defined and highly conserved cis-acting motif within the GATA-4 promoter. These data therefore suggest a mechanism whereby ROS act in pluripotential cells in vivo to regulate the initial transcription of critical tissue-restricted determinant(s) of the cardiomyocyte phenotype, including GATA-4. The ROS-dependent activation, mediated by Nox4, of widely expressed redox-regulated transcription factors, such as c-Jun, is fundamental to this process. PMID:23589292

Murray, Thomas V A; Smyrnias, Ioannis; Shah, Ajay M; Brewer, Alison C

2013-04-15

351

Regulation of cyclooxygenase-2 and cytosolic phospholipase A2 gene expression by lipopolysaccharide through the RNA-binding protein HuR: involvement of NADPH oxidase, reactive oxygen species and mitogen-activated protein kinases  

PubMed Central

BACKGROUND AND PURPOSE Lipopolysaccharide (LPS)-induced expression of cyclooxygenase-2 (COX-2) and cytosolic phospholipase A2 (cPLA2) has been implicated in several respiratory diseases. HuR is known to enhance the expression of genes by binding to 3?-untranslated region (3?-UTR) of mRNA and stabilizing mRNA. However, the exact mechanisms by which HuR affects the stability of mRNA and modulates LPS-induced COX-2 and cPLA2 expression in human tracheal smooth muscle cells (HTSMCs) are not known. EXPERIMENTAL APPROACH The expression of prostaglandin E2 (PGE2) was measured by ELISA, and pro-inflammatory proteins were determined by use of a promoter assay, PCR or Western blot analysis. Overexpression of siRNAs to knock down the target components was used to manipulate the expression of HuR. Release of reactive oxygen species (ROS) was detected by fluorescence dye. The activation of signalling components was assessed by comparing phosphorylation levels, localization of protein kinases or coimmunoprecipitation assay. KEY RESULTS LPS induced COX-2 and cPLA2 expression via post-translational regulation of mRNA stabilization, which were attenuated by transfection with HuR siRNA in HTSMCs. In addition, LPS-stimulated NADPH oxidase activation and ROS generation were attenuated by the NADPH oxidase inhibitors diphenyleneiodonium chloride (DPI) and apocynin (APO). Generation of ROS induced phosphorylation of p42/p44 mitogen-activated protein kinase (MAPK), p38 MAPK and JNK1/2, which was attenuated by DPI and APO and the ROS scavenger N-acetylcysteine. CONCLUSIONS AND IMPLICATIONS These results suggested that in HTSMCs, LPS-induced COX-2 and cPLA2 expression is mediated through NADPH oxidase/ROS-dependent MAPKs associated with HuR accumulation in the cytoplasm. Activated MAPKs may regulate the nucleocytoplasmic shuttling of HuR, and thus induce the cytoplasmic accumulation of HuR.

Lin, Wei-Ning; Lin, Chih-Chung; Cheng, Hsin-Yi; Yang, Chuen-Mao

2011-01-01

352

A Plastid Terminal Oxidase Associated with Carotenoid Desaturation during Chromoplast Differentiation1  

Microsoft Academic Search

The Arabidopsis IMMUTANS gene encodes a plastid homolog of the mitochondrial alternative oxidase, which is associated with phytoene desaturation. Upon expression in Escherichia coli, this protein confers a detectable cyanide-resistant electron transport to isolated membranes. In this assay this activity is sensitive to n-propyl-gallate, an inhibitor of the alternative oxidase. This protein appears to be a plastid terminal oxidase (PTOX)

Eve-Marie Josse; Andrew J. Simkin; Joel Gaffe; Anne-Marie Laboure; Marcel Kuntz; Pierre Carol

2000-01-01

353

Involvement of SenC in Assembly of Cytochrome c Oxidase in Rhodobacter capsulatus  

Microsoft Academic Search

SenC, a Sco1 homolog found in the purple photosynthetic bacteria, has been implicated in affecting photosynthesis and respiratory gene expression, as well as assembly of cytochrome c oxidase. In this study, we show that SenC from Rhodobacter capsulatus is involved in the assembly of a fully functional cbb3-type cytochrome c oxidase, as revealed by decreased cytochrome c oxidase activity in

Danielle L. Swem; Lee R. Swem; Aaron Setterdahl; Carl E. Bauer

2005-01-01

354

De novo microdeletion of Xp11.3 exclusively encompassing the monoamine oxidase A and B genes in a male infant with episodic hypotonia: a genomics approach to personalized medicine.  

PubMed

Monoamine oxidase A and B (MAOA and MAOB) play key roles in deaminating neurotransmitters and various other biogenic amines. Patients deficient in one or both enzymes have distinct metabolic and neurologic profiles. MAOB deficient patients exhibit normal clinical characteristics and behavior, while MAOA deficient patients have borderline intellectual deficiency and impaired impulse control. Patients who lack both MAOA and MAOB have the most extreme laboratory values (urine, blood, and CSF serotonin 4-6 times normal, with elevated O-methylated amine metabolites and reduced deaminated metabolites) in addition to severe intellectual deficiency and behavioral problems. Mice lacking maoa and moab exhibit decreased proliferation of neural stem cells beginning in late gestation and persisting into adulthood. These mice show significantly increased monoamine levels, particularly serotonin, as well as anxiety-like behaviors as adults, suggesting that brain maturation in late embryonic development is adversely affected by elevated serotonin levels. We report the case of a male infant with a de novo Xp11.3 microdeletion exclusively encompassing the MAOA and MAOB genes. This newly recognized X-linked disorder is characterized by severe intellectual disability and unusual episodes of hypotonia, which resemble atonic seizures, but have no EEG correlate. A customized low dietary amine diet was implemented in an attempt to prevent the cardiovascular complications that can result from the excessive intake of these compounds. This is the second report of this deletion and the first attempt to maintain the patient's cardiovascular health through dietary manipulation. Even though a diet low in tyramine, phenylethylamine, and dopa/dopamine is necessary for long-term management, it will not rescue the abnormal monoamine profile seen in combined MAOA and MAOB deficiency. Our patient displays markedly elevated levels of serotonin in blood, serum, urine, and CSF while on this diet. Serotonin biosynthesis inhibitors like para-chlorophenylalanine and p-ethynylphenylalanine may be needed to lower serotonin levels in patients with absent monoamine oxidase enzymes. PMID:22365943

O'Leary, Ryan E; Shih, Jean C; Hyland, Keith; Kramer, Nancy; Asher, Y Jane Tavyev; Graham, John M

2012-02-03

355

De novo microdeletion of Xp11.3 exclusively encompassing the monoamine oxidase A and B genes in a male infant with episodic hypotonia: A genomics approach to personalized medicine  

PubMed Central

Monoamine oxidase A and B (MAOA and MAOB) play key roles in deaminating neurotransmitters and various other biogenic amines. Patients deficient in one or both enzymes have distinct metabolic and neurologic profiles. MAOB deficient patients exhibit normal clinical characteristics and behavior, while MAOA deficient patients have borderline intellectual deficiency and impaired impulse control. Patients who lack both MAOA and MAOB have the most extreme laboratory values (urine, blood, and CSF serotonin 4–6 times normal, with elevated O-methylated amine metabolites and reduced deaminated metabolites) in addition to severe intellectual deficiency and behavioral problems. Mice lacking maoa and moab exhibit decreased proliferation of neural stem cells beginning in late gestation and persisting into adulthood These mice show significantly increased monoamine levels, particularly serotonin, as well as anxiety-like behaviors as adults, suggesting that brain maturation in late embryonic development is adversely affected by elevated serotonin levels. We report the case of a male infant with a de novo Xp11.3 microdeletion exclusively encompassing the MAOA and MAOB genes. This newly recognized X-linked disorder is characterized by severe intellectual disability and unusual episodes of hypotonia, which resemble atonic seizures, but have no EEG correlate. A customized low dietary amine diet was implemented in an attempt to prevent the cardiovascular complications that can result from the excessive intake of these compounds. This is the second report of this deletion and the first attempt to maintain the patient’s cardiovascular health through dietary manipulation. Even though a diet low in tyramine, phenylethylamine, and dopa/dopamine is necessary for long-term management, it will not rescue the abnormal monoamine profile seen in combined MAOA and MAOB deficiency. Our patient displays markedly elevated levels of serotonin in blood, serum, urine, and CSF while on this diet. Serotonin biosynthesis inhibitors like para-chlorophenylalanine and p-ethynylphenylalanine may be needed to lower serotonin levels in patients with absent monoamine oxidase enzymes.

O'Leary, Ryan E.; Shih, Jean C.; Hyland, Keith; Kramer, Nancy; Asher, Y. Jane Tavyev; Graham, John M.

2012-01-01

356

Lysyl Oxidase and Lysyl Oxidase-Like Enzymes  

Microsoft Academic Search

\\u000a Lysyl oxidase (LOX) and its four congeners, lysyl oxidase-like 1 (LOXL1), -2, -3, and -4, have received much investigative\\u000a attention in recent years. LOX itself, is the prototypic form of these amine oxidase enzymes. LOX has long been considered\\u000a to function exclusively as the enzyme that oxidizes peptidyl lysine in its collagen and elastin substrates, thereby initiating\\u000a formation of the

Herbert M. Kagan; Faina Ryvkin

357

A molecular pinwheel multicopper(I) cluster, [(L(S-))6Cu(I)13(S2-)2]3+ with mu4-sulfido, mu3-thiolato and nitrogen ligands.  

PubMed

A copper(I) complex with new N2S thiol ligand transforms to a multicopper(I) cluster, [(L(S-))6Cu(I)13(S2-)2]3+ (1); its X-ray structure exhibiting mu4-sulfido and mu3-thiolato coordination is presented and compared to other cuprous thiolato/sulfido clusters including that observed in the copper enzyme nitrous oxide reductase. PMID:16446829

Lee, Yunho; Sarjeant, Amy A Narducci; Karlin, Kenneth D

2005-12-21

358

A Community-Based Study of Cigarette Smoking Behavior in Relation to Variation in Three Genes Involved in Dopamine Metabolism: Catechol-O-methyltransferase (COMT), Dopamine Beta-Hydroxylase (DBH) and Monoamine Oxidase-A (MAO-A)  

PubMed Central

Objective Cigarette smoking behavior may be influenced by catechol-O-methlyltransferase (COMT), dopamine beta-hydroxylase (DBH), and monamine oxidase-A (MAO-A), genes that play roles in dopamine metabolism. The association between common polymorphisms of these genes and smoking behavior was assessed among 10,059 Caucasian volunteers in Washington County, MD in 1989. Methods Age-adjusted logistic regression was used to measure the association between variants of these single nucleotide polymorphisms and smoking initiation and persistent smoking. Results Overall, no association was seen between each genotype and smoking behavior. However, among younger (<54 years) women, the COMT GG genotype was positively associated with smoking initiation (OR=1.3; 95% CI: 1.1, 1.5), and the MAO-A TT genotype was inversely associated with persistent smoking (OR=0.5; 95% CI: 0.3, 0.9). Men who smoked fewer than 10 cigarettes per day were more likely to be persistent smokers if they had the COMT GG (OR=1.7; 95% CI: 1.0, 2.9) or the DBH GG (OR=1.6; 95% CI: 1.0, 2.6) genotypes. Conclusion Overall the results of this large community-based study do not provide evidence to support the presence of important associations between variants of COMT, DBH, or MAO-A and smoking initiation or persistent smoking.

Shiels, Meredith S.; Huang, Han Yao; Hoffman, Sandra C.; Shugart, Yin Yao; Bolton, Judy Hoffman; Platz, Elizabeth A.; Helzlsouer, Kathy J.; Alberg, Anthony J.

2008-01-01

359

The cbb3-type cytochrome c oxidase from Rhodobacter sphaeroides, a proton-pumping heme-copper oxidase.  

PubMed

Rhodobacter sphaeroides expresses a bb3-type quinol oxidase, and two cytochrome c oxidases: cytochrome aa3 and cytochrome cbb3. We report here the characterization of the genes encoding this latter oxidase. The ccoNOQP gene cluster of R. sphaeroides contains four open reading frames with high similarity to all ccoNOQP/fixNOQP gene clusters reported so far. CcoN has the six highly conserved histidines proposed to be involved in binding the low spin heme, and the binuclear center metals. ccoO and ccoP code for membrane bound mono- and diheme cytochromes c. ccoQ codes for a small hydrophobic protein of unknown function. Upstream from the cluster there is a conserved Fnr/FixK-like box which may regulate its expression. Analysis of a R. sphaeroides mutant in which the ccoNOQP gene cluster was inactivated confirms that this cluster encodes the cbb3-type oxidase previously purified. Analysis of proton translocation in several strains shows that cytochrome cbb3 is a proton pump. We also conclude that cytochromes cbb3 and aa3 are the only cytochrome c oxidases in the respiratory chain of R. sphaeroides. PMID:9711295

Toledo-Cuevas, M; Barquera, B; Gennis, R B; Wikström, M; García-Horsman, J A

1998-07-20

360

Ascorbate Oxidase-Dependent Changes in the Redox State of the Apoplast Modulate Gene Transcript Accumulation Leading to Modified Hormone Signaling and Orchestration of Defense Processes in Tobacco1[W  

PubMed Central

The role of the redox state of the apoplast in hormone responses, signaling cascades, and gene expression was studied in transgenic tobacco (Nicotiana tabacum) plants with modified cell wall-localized ascorbate oxidase (AO). High AO activity specifically decreased the ascorbic acid (AA) content of the apoplast and altered plant growth responses triggered by hormones. Auxin stimulated shoot growth only when the apoplastic AA pool was reduced in wild-type or AO antisense lines. Oxidation of apoplastic AA in AO sense lines was associated with loss of the auxin response, higher mitogen-activated protein kinase activities, and susceptibility to a virulent strain of the pathogen Pseudomonas syringae. The total leaf glutathione pool, the ratio of reduced glutathione to glutathione disulfide, and glutathione reductase activities were similar in the leaves of all lines. However, AO sense leaves exhibited significantly lower dehydroascorbate reductase and ascorbate peroxidase activities than wild-type and antisense leaves. The abundance of mRNAs encoding antioxidant enzymes was similar in all lines. However, the day/night rhythms in the abundance of transcripts encoding the three catalase isoforms were changed in response to the AA content of the apoplast. Other transcripts influenced by AO included photorespiratory genes and a plasma membrane Ca2+ channel-associated gene. We conclude that the redox state of the apoplast modulates plant growth and defense responses by regulating signal transduction cascades and gene expression patterns. Hence, AO activity, which modulates the redox state of the apoplastic AA pool, strongly influences the responses of plant cells to external and internal stimuli.

Pignocchi, Cristina; Kiddle, Guy; Hernandez, Iker; Foster, Simon J.; Asensi, Amparo; Taybi, Tahar; Barnes, Jeremy; Foyer, Christine H.

2006-01-01

361

Coupling of energy metabolism and synaptic transmission at the transcriptional level: Role of nuclear respiratory factor 1 in regulating both cytochrome c oxidase and NMDA glutamate receptor subunit genes  

PubMed Central

Neuronal activity and energy metabolism are tightly coupled processes. Regions high in neuronal activity, especially of the glutamatergic type, have high levels of cytochrome c oxidase (COX). Perturbations in neuronal activity affect the expressions of COX and glutamatergic N-methyl-D-aspartate receptor subunit 1 (NR1). The present study sought to test our hypothesis that the coupling extends to the transcriptional level, whereby NR1 and possibly other NR subunits and COX are co-regulated by the same transcription factor, nuclear respiratory factor 1 (NRF-1), which regulates all COX subunit genes. By means of multiple approaches, including in silico analysis, electrophoretic mobility shift and supershift assays, in vivo chromatin immunoprecipitation, promoter mutations, and real-time quantitative PCR, NRF-1 was found to functionally bind to the promoters of Grin 1 (NR1), Grin 2b (NR2b) and COX subunit genes, but not of Grin2a and Grin3a genes. These transcripts were up-regulated by KCl and down-regulated by TTX in cultured primary neurons. However, silencing of NRF-1 with small interference RNA blocked the up-regulation of Grin1, Grin2b, and COX induced by KCl, and over-expression of NRF-1 rescued these transcripts that were suppressed by TTX. NRF-1 binding sites on Grin1 and Grin2b genes are also highly conserved among mice, rats, and humans. Thus, NRF-1 is an essential transcription factor critical in the co-regulation of NR1, NR2b, and COX, and coupling exists at the transcriptional level to ensure coordinated expressions of proteins important for synaptic transmission and energy metabolism.

Dhar, Shilpa S.; Wong-Riley, Margaret T. T.

2009-01-01

362

NADH oxidase of plasma membranes  

Microsoft Academic Search

NADH oxidase is a cyanide-resistant and hormone-responsive oxidase intrinsic to the plasma membrane of both plant and animal cells. The activity has many unique characteristics that distinguish it from other oxidases and oxidoreductases of both organelles and internal membranes and from other oxidoreductases of the plasma membrane. Among these are resistance to inhibition by cyanide, catalase, superoxide dismutase, and phenylchloromer-curibenzoate.

D. James Morré; Andrew O. Brightman

1991-01-01

363

TNF-{alpha} upregulates the A{sub 2B} adenosine receptor gene: The role of NAD(P)H oxidase 4  

SciTech Connect

Proliferation of vascular smooth muscle cells (VSMC), oxidative stress, and elevated inflammatory cytokines are some of the components that contribute to plaque formation in the vasculature. The cytokine tumor necrosis factor-alpha (TNF-{alpha}) is released during vascular injury, and contributes to lesion formation also by affecting VSMC proliferation. Recently, an A{sub 2B} adenosine receptor (A{sub 2B}AR) knockout mouse illustrated that this receptor is a tissue protector, in that it inhibits VSMC proliferation and attenuates the inflammatory response following injury, including the release of TNF-{alpha}. Here, we show a regulatory loop by which TNF-{alpha} upregulates the A{sub 2B}AR in VSMC in vitro and in vivo. The effect of this cytokine is mimicked by its known downstream target, NAD(P)H oxidase 4 (Nox4). Nox4 upregulates the A{sub 2B}AR, and Nox inhibitors dampen the effect of TNF-{alpha}. Hence, our study is the first to show that signaling associated with Nox4 is also able to upregulate the tissue protecting A{sub 2B}AR.

St Hilaire, Cynthia; Koupenova, Milka; Carroll, Shannon H.; Smith, Barbara D. [Department of Biochemistry, Whitaker Cardiovascular Institute, Boston University School of Medicine, 715 Albany Street, Boston, MA 02118 (United States); Ravid, Katya [Department of Biochemistry, Whitaker Cardiovascular Institute, Boston University School of Medicine, 715 Albany Street, Boston, MA 02118 (United States)], E-mail: ravid@biochem.bumc.bu.edu

2008-10-24

364

Genetic characterization of the partial mitochondrial cytochrome oxidase c subunit I (cox 1) gene of the zoonotic parasitic nematode, Ancylostoma ceylanicum from humans, dogs and cats.  

PubMed

Ancylostoma ceylanicum is the only zoonotic hookworm species that is able to produce patent infections in humans with the majority of cases reported in South East Asia. Over the past few years, there have been an increasing number of studies investigating the prevalence of this parasitic zoonosis using molecular diagnostic tools and a single genetic locus as marker for species identification. As there can be limitations in using a single genetic locus for epidemiological studies and genetic discrimination, the complementary use of a more variable locus will provide additional evidence to support the zoonotic exchange of hookworm species between humans and animals. In the present study, the cytochrome c oxidase subunit 1 (cox 1) sequence of A. ceylanicum from positive human and animal fecal samples were determined and compared with published reference sequences. Phylogenetic analysis demonstrated that isolates of A. ceylanicum were divided into two clusters, one consisting 3 human isolates and the other comprising 19 isolates of human and animal origin from different geographical locations within Malaysia. The two groups of A. ceylanicum could be distinguished from one another through five fixed nucleotide differences at locations 891, 966, 1008, 1077 and 1083. The detection of genetically distinct groups and considerable level of genetic variation within the cox 1 sequence of A. ceylanicum might suggest potential haplotype-linked differences in zoonotic, epidemiological and pathobiological characteristics, a hypothesis that still needs further investigation. PMID:23774318

Ngui, Romano; Mahdy, Mohammed A K; Chua, Kek Heng; Traub, Rebecca; Lim, Yvonne A L

2013-06-14

365

Evidence for interplay between genes and maternal stress in utero: monoamine oxidase A polymorphism moderates effects of life events during pregnancy on infant negative emotionality at 5?weeks.  

PubMed

The low activity variant of the monoamine oxidase A (MAOA) functional promoter polymorphism, MAOA-LPR, in interaction with adverse environments (G?×?E) is associated with child and adult antisocial behaviour disorders. MAOA is expressed during foetal development so in utero G?×?E may influence early neurodevelopment. We tested the hypothesis that MAOA G?×?E during pregnancy predicts infant negative emotionality soon after birth. In an epidemiological longitudinal study starting in pregnancy, using a two stage stratified design, we ascertained MAOA-LPR status (low vs. high activity variants) from the saliva of 209 infants (104 boys and 105 girls), and examined predictions to observed infant negative emotionality at 5?weeks post-partum from life events during pregnancy. In analyses weighted to provide estimates for the general population, and including possible confounders for life events, there was an MAOA status by life events interaction (P?=?0.017). There was also an interaction between MAOA status and neighbourhood deprivation (P?=?0.028). Both interactions arose from a greater effect of increasing life events on negative emotionality in the MAOA-LPR low activity, compared with MAOA-LPR high activity infants. The study provides the first evidence of moderation by MAOA-LPR of the effect of the social environment in pregnancy on negative emotionality in infancy, an early risk for the development of child and adult antisocial behaviour disorders. PMID:23480342

Hill, J; Breen, G; Quinn, J; Tibu, F; Sharp, H; Pickles, A

2013-05-07

366

DEVELOPMENTAL REGULATION OF PEACH ACC OXIDASE-GUS FUSIONS IN TRANSGENIC TOMATO FRUITS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Fruit ripening involves changes in the expression of a large number of genes including the well-characterized 1-Aminocyclopropane-1-caboxylic acid oxidase which catalyzes the conversion of 1-aminocyclopropane-1-caboxylate to ethylene. We isolated a genomic DNA sequence encoding ACC oxidase from pea...

367

Epigenetic inhibition of lysyl oxidase transcription after transformation by ras oncogene  

Microsoft Academic Search

Lysyl oxidase is an extracellular enzyme involved in connective tissue maturation that also acts as a phenotypic suppressor of the ras oncogene. To understand how this suppressor is controlled, gene transcription was studied and the promoter was characterized. Nuclear runoff transcription assays indicated that the markedly reduced amounts of lysyl oxidase message detected after ras transformation resulted from inhibition of

Sara Contente; Kaylene Kenyon; Priya Sriraman; Savitri Subramanyan; Robert M. Friedman

1999-01-01

368

Recovery of choline oxidase activity by in vitro recombination of individual segments  

Microsoft Academic Search

Initial attempts to express a choline oxidase from Arthrobacter pascens (APChO-syn) in Escherichia coli starting from a synthetic gene only led to inactive protein. However, activity was regained by the systematic exchange of\\u000a individual segments of the gene with segments from a choline oxidase-encoding gene from Arthrobacter globiformis yielding a functional chimeric enzyme. Next, a sequence alignment of the exchanged

Birgit Heinze; Nina Hoven; Timothy O’Connell; Karl-Heinz Maurer; Sebastian Bartsch; Uwe T. Bornscheuer

2008-01-01

369

Role of amine oxidase expression to maintain putrescine homeostasis in Rhodococcus opacus.  

PubMed

While applications of amine oxidases are increasing, few have been characterised and our understanding of their biological role and strategies for bacteria exploitation are limited. By altering the nitrogen source (NH4Cl, putrescine and cadaverine (diamines) and butylamine (monoamine)) and concentration, we have identified a constitutive flavin dependent oxidase (EC 1.4.3.10) within Rhodococcus opacus. The activity of this oxidase can be increased by over two orders of magnitude in the presence of aliphatic diamines. In addition, the expression of a copper dependent diamine oxidase (EC 1.4.3.22) was observed at diamine concentrations>1mM or when cells were grown with butylamine, which acts to inhibit the flavin oxidase. A Michaelis-Menten kinetic treatment of the flavin oxidase delivered a Michaelis constant (KM)=190?M and maximum rate (kcat)=21.8s(-1) for the oxidative deamination of putrescine with a lower KM (=60?M) and comparable kcat (=18.2s(-1)) for the copper oxidase. MALDI-TOF and genomic analyses have indicated a metabolic clustering of functionally related genes. From a consideration of amine oxidase specificity and sequence homology, we propose a putrescine degradation pathway within Rhodococcus that utilises oxidases in tandem with subsequent dehydrogenase and transaminase enzymes. The implications of PUT homeostasis through the action of the two oxidases are discussed with respect to stressors, evolution and application in microbe-assisted phytoremediation or bio-augmentation. PMID:23540932

Foster, Alexander; Barnes, Nicole; Speight, Robert; Morris, Peter C; Keane, Mark A

2013-01-17

370

Cloning and characterization of a fifth human lysyl oxidase isoenzyme: the third member of the lysyl oxidase-related subfamily with four scavenger receptor cysteine-rich domains  

Microsoft Academic Search

We report the complete cDNA sequence of the human lysyl oxidase-like 4 (LOXL4) gene, a new member of the lysyl oxidase (LO) gene family. The predicted polypeptide is 756 amino acids long, including a 24-residue signal peptide. The C-terminal region contains a LO domain similar to those of LOX, LOXL, LOXL2 and LOXL3. The N-terminal region has four subregions similar

Joni M. Mäki; Hilkka Tikkanen; Kari I. Kivirikko

2001-01-01

371

Typing of Candida glabrata in Clinical Isolates by Comparative Sequence Analysis of the Cytochrome c Oxidase Subunit 2 Gene Distinguishes Two Clusters of Strains Associated with Geographical Sequence Polymorphisms  

PubMed Central

We tested whether comparative sequence analysis of the mitochondrion-encoded cytochrome c oxidase subunit 2 gene (COX2) could be used to distinguish intraspecific variants of Candida glabrata. Mitochondrial genes are suitable for investigation of close phylogenetic relationships because they evolve much faster than nuclear genes, which in general exhibit very limited intraspecific variation. For this survey we used 11 clinical isolates of C. glabrata from three different geographical locations in Brazil, 10 isolates from one location in the United States, 1 American Type Culture Collection strain as an internal control, and the published sequence of strain CBS 138. The complete coding region of COX2 was amplified from total cellular DNA, and both strands were sequenced twice for each strain. These sequences were aligned with published sequences from other fungi, and the numbers of substitutions and phylogenetic relationships were determined. Typing of these strains was done by using 17 substitutions, with 8 being nonsynonymous and 9 being synonymous. Also, cDNAs made from purified mitochondrial polyadenylated RNA were sequenced to confirm that our sequences correspond to the expressed copies and not nuclear pseudogenes and that a frameshift mutation exists in the 3? end of the coding region (position 673) relative to the Saccharomyces cerevisiae sequence and the previously published C. glabrata sequence. We estimated the average evolutionary rate of COX2 to be 11.4% sequence divergence/108 years and that phylogenetic relationships of yeasts based on these sequences are consistent with rRNA sequence data. Our analysis of COX2 sequences enables typing of C. glabrata strains based on 13 haplotypes and suggests that positions 51 and 519 indicate a geographical polymorphism that discriminates strains isolated in the United States and strains isolated in Brazil. This provides for the first time a means of typing of Candida strains that cause infections by use of direct sequence comparisons and the associated divergence estimates.

Sanson, Gerdine F. O.; Briones, Marcelo R. S.

2000-01-01

372

Lysyl oxidase like 4, a novel target gene of TGF-?1 signaling, can negatively regulate TGF-?1-induced cell motility in PLC\\/PRF\\/5 hepatoma cells  

Microsoft Academic Search

Transforming growth factor-?1 (TGF-?1) is a multi-functional cytokine involved in the regulation of cell proliferation, differentiation and extracellular matrix formation. In search for novel genes mediating the TGF-?1 function at downstream signaling, we performed a cDNA microarray analysis and identified 60 genes whose expression is regulated by TGF-?1 in the liver cancer cell line PLC\\/PRF\\/5. Among them, we report here

Dong Joon Kim; Dong Chul Lee; Suk-Jin Yang; Jung Ju Lee; Eun Mi Bae; Dong Min Kim; Sang Hyun Min; Soo Jung Kim; Dong Chul Kang; Byung Chan Sang; Pyung Keun Myung; Kyung Chan Park; Young Il Yeom

2008-01-01

373

Catechol oxidase — structure and activity  

Microsoft Academic Search

Recently determined structures of copper-containing plant catechol oxidase in three different catalytic states have provided new insights into the mechanism of this enzyme and its relationship to other copper type-3 proteins. Moreover, the active site of catechol oxidase has been found to be structurally conserved with the oxygen-binding site of a molluscan hemocyanin.

Christoph Eicken; Bernt Krebs; James C Sacchettini

1999-01-01

374

Expression of phenol oxidase and heat-shock genes during the development of Agaricus bisporus fruiting bodies, healthy and infected by Lecanicillium fungicola.  

PubMed

The fungal pathogen Lecanicillium fungicola (formerly Verticillium fungicola) is responsible for severe losses worldwide in the mushroom (Agaricus bisporus) industry. Infected crops are characterised by masses of undifferentiated tissue (bubbles) growing in place of sporophores. The expression of three laccase genes (lcc1, lcc2 and lcc3), two tyrosinase genes (AbPPO1 and AbPPO2) and the hspA gene encoding a heat-shock protein known to be potentially associated with host-pathogen interaction was investigated in mycelial aggregates and during the development of healthy sporophores and bubbles of a susceptible cultivar. The lcc3, AbPPO2 and hspA genes were each expressed at different levels at the different stages of sporophore morphogenesis, whilst they showed a stable expression throughout bubble development. The transcript levels were similar in bubbles and at the first developmental stage of healthy fruiting bodies, both showing no tissue differentiation. These observations suggest that lcc3, AbPPO2 and hspA are associated with A. bisporus morphogenesis. Comparing the expression of the hspA gene in three susceptible and three tolerant strains showed that the latter displayed a higher level of transcript in the primordium, which is the stage receptive to the pathogen. The six strains exhibited a comparable expression in the vegetative mycelium, non-receptive to L. fungicola. PMID:19711071

Largeteau, Michèle L; Latapy, Camille; Minvielle, Nathalie; Regnault-Roger, Catherine; Savoie, Jean-Michel

2009-08-27

375

Transcriptional coupling of synaptic transmission and energy metabolism: Role of nuclear respiratory factor 1 in co-regulating neuronal nitric oxide synthase and cytochrome c oxidase genes in neurons  

PubMed Central

SUMMARY Neuronal activity is highly dependent on energy metabolism; yet, the two processes have traditionally been regarded as independently regulated at the transcriptional level. Recently, we found that the same transcription factor, nuclear respiratory factor 1 (NRF-1) co-regulates an important energy-generating enzyme, cytochrome c oxidase, as well as critical subunits of glutamatergic receptors. The present study tests our hypothesis that the co-regulation extends to the next level of glutamatergic synapses, namely, neuronal nitric oxide synthase, which generates nitric oxide as a downstream signaling molecule. Using in silico analysis, electrophoretic mobility shift assay, chromatin immunoprecipitation, promoter mutations, and NRF-1 silencing, we documented that NRF-1 functionally bound to Nos1, but not Nos2 (inducible) and Nos3 (endothelial) gene promoters. Both COX and Nos1 transcripts were up-regulated by depolarizing KCl treatment and down-regulated by TTX-mediated impulse blockade in neurons. However, NRF-1 silencing blocked the up-regulation of both Nos1 and COX induced by KCl depolarization, and over-expression of NRF-1 rescued both Nos1 and COX transcripts downregulated by TTX. These findings are consistent with our hypothesis that synaptic neuronal transmission and energy metabolism are tightly coupled at the molecular level.

Dhar, Shilpa S.; Liang, Huan Ling; Wong-Riley, Margaret T. T.

2009-01-01

376

Molecular cloning and characterization of the NADPH oxidase from the kuruma shrimp, Marsupenaeus japonicus: early gene up-regulation after Vibrio penaeicida and poly(I:C) stimulations in vitro.  

PubMed

Free radicals such as nitric oxide (NO) and reactive oxygen species (ROS) are involved in many physiological processes. In humans, there are 5 homologs of nicotinamide adenine dinucleotide phosphate (NADPH) oxidases (Noxes) that generate superoxide (O(2)(-)), which can dismute to produce ROS, and play significant roles in innate immunity and cell proliferation. Though Noxes have been identified in vertebrates (humans and fishes) and some insects, there are very few reports investigating Noxes in crustaceans. In the present study, we describe the entire cDNA sequence (4216 bp) of Marsupenaeus japonicus (kuruma shrimp) Nox (MjNox) generated using reverse transcriptase-polymerase chain reaction (RT-PCR) and random amplification of cDNA ends (RACE). The open reading frame of MjNox encodes a protein of 1280 amino acids with an estimated mass of 146 kDa that has 46.8% sequence homology with the Nox gene of the fruit fly, Drosophila melanogaster. Highly conserved amino acid sequences were observed in the NADPH binding domain. Transcriptional analysis revealed that MjNox mRNA is highly expressed in the lymphoid organ, hepatopancreas and hemocytes of the healthy kuruma shrimp. In the hemocytes, MjNox expression reached its peak 4 h after stimulation with either Vibrio penaeicida or poly(I:C) and decreased to its normal level after 12 h.This study is the first to identify and clone a Nox family member (MjNox) from a crustacean species. PMID:22133377

Inada, Mari; Sudhakaran, Raja; Kihara, Keisuke; Nishi, Junichi; Yoshimine, Maki; Mekata, Tohru; Kono, Tomoya; Sakai, Masahiro; Yoshida, Terutoyo; Itami, Toshiaki

2011-11-22

377

Cloning and expression pattern of peroxisomal beta-oxidation genes palmitoyl-CoA oxidase, multifunctional protein and 3-ketoacyl-CoA thiolase in mussel Mytilus galloprovincialis and thicklip grey mullet Chelon labrosus.  

PubMed

Due to the ability to respond after exposure to organic toxic compounds, peroxisome proliferation is used as biomarker of exposure to organic pollutants in mussels and in fish. Mussels are worldwide studied as sentinels of pollution in marine environments while mullets such as the thicklip grey mullet Chelon labrosus have been proposed as appropriate sentinel species since they inhabit highly polluted environments. In order to study genes of the inducible peroxisomal beta-oxidation pathway in mussels Mytilus galloprovincialis and in C. labrosus, genes coding for the three enzymes in the inducible peroxisomal beta-oxidation pathway, palmitoyl-CoA oxidase (AOX1), multifunctional protein (MFP1 in mullet and MFP2 in mussels), and 3-ketoacyl-CoA thiolase (THIO), were cloned. Additionally, a fragment of the peroxisomal Delta(2), Delta(4) dienoyl-CoA reductase 2 (DECR) necessary for the beta-oxidation of unsaturated fatty acids was cloned in mullets. The whole open reading frame of aox1 sequenced in both mussels and mullets revealed high homology with known aox1 sequences, with highly conserved important domains such as the FAD binding motif or the typical peroxisomal targeting signal (PTS1). A thorough in silico analysis of the gene and genome databases allowed to identify in fish and molluscs sequence homologs of all the enzymes necessary for 2 of the 3 different paralog peroxisomal beta-oxidation pathways described in metazoans (AOX1, AOX3, MFP1, MFP2, THIO and sterol carrier protein X). Only the enzyme necessary for the oxidation of branched chain fatty acids, AOX2, described in mammalian, avian and amphibian species, seems to be lacking from the genomes of fish and molluscs. In order to study the expression and regulation capacity of peroxisomal beta-oxidation genes, aox1 and thio expression was determined in different tissues of mature and immature mullets and mussels collected in January and June, both genes being expressed higher in the digestive gland of mussels collected in June compared to January. Finally, in silico studies of the promoter regions in the piscine genomes available in the Ensembl genome repository, allowed the identification of putative peroxisome proliferator response elements that could explain the possible cellular and molecular mechanisms leading to peroxisome proliferation in fish. Further studies are needed to decipher molecular mechanisms of peroxisome proliferation in aquatic organisms under exposure to peroxisome proliferator xenobiotics. PMID:19465092

Bilbao, Eider; Cajaraville, Miren P; Cancio, Ibon

2009-05-22

378

Conversion of Pipecolic Acid into Lysine in Penicillium chrysogenum Requires Pipecolate Oxidase and Saccharopine Reductase: Characterization of the lys7 Gene Encoding Saccharopine Reductase  

Microsoft Academic Search

Pipecolic acid is a component of several secondary metabolites in plants and fungi. This compound is useful as a precursor of nonribosomal peptides with novel pharmacological activities. In Penicillium chrysogenum pipecolic acid is converted into lysine and complements the lysine requirement of three different lysine auxotrophs with mutations in the lys1, lys2 ,o rlys3 genes allowing a slow growth of

LEOPOLDO NARANJO; EVA MARTIN DE VALMASEDA; OSCAR BANUELOS; PILAR LOPEZ; JORGE RIANO; JAVIER CASQUEIRO; JUAN F. MARTIN

2001-01-01

379

Evidence for Lateral Transfer of Genes Encoding Ferredoxins, Nitroreductases, NADH Oxidase, and Alcohol Dehydrogenase 3 from Anaerobic Prokaryotes to Giardialamblia and Entamoebahistolytica  

Microsoft Academic Search

Giardia lamblia and Entamoeba histolytica are amitochondriate, microaerophilic protists which use fermen- tation enzymes like those of bacteria to survive anaerobic conditions within the intestinal lumen. Genes encoding fermentation enzymes and related electron transport peptides (e.g., ferredoxins) in giardia organisms and amebae are hypothesized to be derived from either an ancient anaerobic eukaryote (amitochondriate fossil hypothesis), a mitochondrial endosymbiont (hydrogen

Julie E. J. Nixon; Amy Wang; Jessica Field; Hilary G. Morrison; Andrew G. McArthur; Mitchell L. Sogin; Brendan J. Loftus; John Samuelson

2002-01-01

380

Characterization of novel gene expression related to glyoxal oxidase by agro-infiltration of the leaves of accession Baihe-35-1 of Vitis pseudoreticulata involved in production of H2O2 for resistance to Erysiphe necator.  

PubMed

Glyoxal oxidase (GLOX), an extracellular H(2)O(2)-producing enzyme, has been reported in Phanerochaete chrysosporium and Ustilago maydis. We previously isolated a grapevine GLOX gene from the highly resistant to Erysiphe necator Chinese wild Vitis pseudoreticulata accession Baihe-35-1 and designated it as VpGLOX (GenBank accession no. DQ201181). Transient expression of VpGLOX can suppress Powdery Mildew in susceptible genotype were studied. To further investigate the function of the VpGLOX gene, real-time PCR and Western blot analysis were performed to examine expression patterns at transcriptional and translational levels, respectively. The results showed that VpGLOX expression at the transcriptional level increased significantly in the disease-resistant accession Baihe-35-1 after Erysiphe necator inoculation, but no significant changes in the susceptible accession, V. pseudoreticulata accession Guangxi-2 could be observed. As evident from a Western blot analysis, VpGLOX protein increased slightly in Baihe-35-1 after E. necator inoculation, but not statistical significant difference changes in Guangxi-2. The immunolocalization via immunogold electron microscopy showed that VpGLOX was mainly located in the adaxial epidermal cell wall of E. necator-inoculated leaves of both Baihe-35-1 and Guangxi-2. Agrobacterium-mediated transient expression assays revealed that VpGLOX expression could produce H(2)O(2), which may directly play a role in defense mechanism during plant-pathogen interactions. Our results could provide further insight into the biological role of VpGLOX in the defense response against E. necator in V. pseudoreticulata. PMID:23090239

Zhao, Heqing; Guan, Xin; Xu, Yan; Wang, Yuejin

2012-10-23

381

Lysyl oxidase like 4, a novel target gene of TGF-beta1 signaling, can negatively regulate TGF-beta1-induced cell motility in PLC/PRF/5 hepatoma cells.  

PubMed

Transforming growth factor-beta1 (TGF-beta1) is a multi-functional cytokine involved in the regulation of cell proliferation, differentiation and extracellular matrix formation. In search for novel genes mediating the TGF-beta1 function at downstream signaling, we performed a cDNA microarray analysis and identified 60 genes whose expression is regulated by TGF-beta1 in the liver cancer cell line PLC/PRF/5. Among them, we report here lysyl oxidase like 4 (LOXL4) as a novel target of TGF-beta1 signaling, and provide experimental evidence for its expression regulation and function. LOXL4 was found to be the only member of LOX family whose expression is induced by TGF-beta1 in hepatoma cells. Deletion mapping of the LOXL4 promoter indicated that the TGF-beta1 regulation of LOXL4 expression is mediated through the binding of AP1 transcription factor to a conserved region of the promoter. This was confirmed by the chromatin immunoprecipitation assay that captured c-Fos-bound chromatin from TGF-beta1-treated cells. Forced expression of LOXL4 in PLC/PRF/5 cells resulted in inhibition of cell motility through Matrigel in the presence of TGF-beta1 treatment. In parallel, LOXL4 suppressed the expression of laminins and alpha3 integrin and the activity of MMP2. These results suggest that LOXL4 may function as a negative feedback regulator of TGF-beta1 in cell invasion by inhibiting the metabolism of extracellular matrix (ECM) components. PMID:18586005

Kim, Dong Joon; Lee, Dong Chul; Yang, Suk-Jin; Lee, Jung Ju; Bae, Eun Mi; Kim, Dong Min; Min, Sang Hyun; Kim, Soo Jung; Kang, Dong Chul; Sang, Byung Chan; Myung, Pyung Keun; Park, Kyung Chan; Yeom, Young Il

2008-06-27

382

Molecular phylogeny of the subfamily Gerbillinae (Muridae, Rodentia) with emphasis on species living in the Xinjiang-Uygur Autonomous Region of China and based on the mitochondrial cytochrome b and cytochrome c oxidase subunit II genes.  

PubMed

Rodents belonging to the subfamily Gerbillinae and living in the Xinjiang-Uygur autonomous region of China were collected in field surveys between 2001 and 2003. We found four Meriones species, including M. chengi M. liycus, M. meridianus, and M. tamariscinus, as well as related species from different genera, Rhombomys opimus and Brachiones przewaliskii For phylogenetic analyses of these gerbilline species, DNA sequences of parts of the mitochondrial cytochrome b (Cytb) and cytochrome c oxidase subunit II (COII) genes were examined with the neighbor Joining, maximum parsimony, maximum likelihood, and Bayesian inference methods. Our phylogenetic analyses suggest that the genus Meriones is not monophyletic and place M. tamaricinus as the sister taxon to a clade comprising Brachiones, Psammomys, Rhombomys, and the other Meriones species. The remaining Meriones species separate into three lineages: M. meridianus (including M. chengi), Meriones unguiculatus, and a clade that includes multiple Meriones species originating from Asia, the Middle East, and Africa. The phylogenetic relationships among the genera Brachines, Meriones, Psammomys, and Rhombomys remain ambiguous, probably due to the saturation of mutations that occurs in fast-evolving mitochondrial DNA. In addition, intraspecific variation was observed for M. meridianus, and this mostly correlated with collection localities, i.e., the northern and southern parts of the Xinjiang region. This variation corresponded to interspecific levels of divergence among other lineages of Meriones. Interestingly, no differences were observed in either the Cytb or COII gene sequences isolated from M. chengi collected from the Turfan Basin in the north and those from M. meridianus in the south, suggesting that M. chengi may be a synonym of M. meridianus. PMID:20192696

Ito, Mamoru; Jiang, Wei; Sato, Jun J; Zhen, Qiang; Jiao, Wei; Goto, Kazuo; Sato, Hiroshi; Ishiwata, Kenji; Oku, Yuzaburo; Chai, June-Jie; Kamiya, Haruo

2010-03-01

383

Knockout Corner: Knockout mice for monoamine oxidase A.  

PubMed

A line of transgenic mice was isolated in which transgene integration had caused a deletion in the gene encoding monoamine oxidase A, an enzyme that degrades serotonin and norepinephrine. This has provided an animal model of MAOA deficiency in humans, a condition characterized by borderline mental retardation and impulsive aggression. PMID:11281992

Seif, Isabelle; De Maeyer, Edward

1999-09-01

384

Recombinant Hansenula polymorpha as a biocatalyst: coexpression of the spinach glycolate oxidase ( GO ) and the S. cerevisiae catalase T ( CTT1 ) gene  

Microsoft Academic Search

The methylotrophic yeast Hansenula polymorpha has been developed as an efficient production system for heterologous proteins. The system offers the possibility to cointegrate\\u000a heterologous genes in anticipated fixed copy numbers into the chromosome. As a consequence coproduction of different proteins\\u000a in stoichiometric ratios can be envisaged. This provides options to design this yeast as an industrial biocatalyst in procedures\\u000a where

G. Gellissen; M. Piontek; U. Dahlems; V. Jenzelewski; J. E. Gavagan; R. DiCosimo; D. L. Anton; Z. A. Janowicz

1996-01-01

385

NADPH Oxidase and Neurodegeneration  

PubMed Central

NADPH oxidase (Nox) is a unique, multi-protein, electron transport system that produces large amounts of superoxide via the reduction of molecular oxygen. Nox-derived reactive oxygen species (ROS) are known to be involved in a variety of physiological processes, including host defense and signal transduction. However, over the past decade, the involvement of (Nox)-dependent oxidative stress in the pathophysiology of several neurodegenerative diseases has been increasingly recognized. ROS produced by Nox proteins contribute to neurodegenerative diseases through distinct mechanisms, such as oxidation of DNA, proteins, lipids, amino acids and metals, in addition to activation of redox-sensitive signaling pathways. In this review, we discuss the recent literature on Nox involvement in neurodegeneration, focusing on Parkinson and Alzheimer diseases.

Hernandes, Marina S; Britto, Luiz R G

2012-01-01

386

Enhancing plant growth and fiber production by silencing GA 2-oxidase.  

PubMed

Enhancing plant height and growth rates is a principal objective of the fiber, pulp, wood and biomass product industries. Many biotechnological systems have been established to advance that task with emphasis on increasing the concentration of the plant hormone gibberellin, or on its signalling. In this respect, the most studied gibberellin biosynthesis enzyme is the GA 20-oxidase which catalyses the rate limiting step of the pathway. Overexpression of the gene resulted in an excessively high activity of the gibberellin deactivating enzyme, GA 2-oxidase. Consequently, this feedback regulation limits the intended outcome. We assume that silencing GA 2-oxidase transcription would abolish this antithetical effect, thereby allowing greater gibberellin accumulation. Here, we show that silencing the gibberellin deactivating enzyme in tobacco model plants results in a dramatic improvement of their growth characteristics, compared with the wild type and GA 20-oxidase over-expressing plants. Moreover, the number of xylem fiber cells in the silenced lines exceeded that of GA 20-oxidase over-expressing plants, potentially, making GA 2-oxidase silencing more profitable for the wood and fiber industries. Interestingly, crossing GA 20-oxidase over-expressing plants with GA 2-oxidase silenced plants did not yield consequential additive effects. Our findings unveil the benefits of silencing GA 2-oxidase to substantially increase tobacco growth and fiber production, which suggest using this approach in cultivated forest plantations and industrial herbaceous plants, worldwide. PMID:20070875

Dayan, Jonathan; Schwarzkopf, Maayan; Avni, Adi; Aloni, Roni

2010-01-13

387

The Escherichia coli CydX protein is a member of the CydAB cytochrome bd oxidase complex and is required for cytochrome bd oxidase activity.  

PubMed

Cytochrome bd oxidase operons from more than 50 species of bacteria contain a short gene encoding a small protein that ranges from ?30 to 50 amino acids and is predicted to localize to the cell membrane. Although cytochrome bd oxidases have been studied for more than 70 years, little is known about the role of this small protein, denoted CydX, in oxidase activity. Here we report that Escherichia coli mutants lacking CydX exhibit phenotypes associated with reduced oxidase activity. In addition, cell membrane extracts from ?cydX mutant strains have reduced oxidase activity in vitro. Consistent with data showing that CydX is required for cytochrome bd oxidase activity, copurification experiments indicate that CydX interacts with the CydAB cytochrome bd oxidase complex. Together, these data support the hypothesis that CydX is a subunit of the CydAB cytochrome bd oxidase complex that is required for complex activity. The results of mutation analysis of CydX suggest that few individual amino acids in the small protein are essential for function, at least in the context of protein overexpression. In addition, the results of analysis of the paralogous small transmembrane protein AppX show that the two proteins could have some overlapping functionality in the cell and that both have the potential to interact with the CydAB complex. PMID:23749980

VanOrsdel, Caitlin E; Bhatt, Shantanu; Allen, Rondine J; Brenner, Evan P; Hobson, Jessica J; Jamil, Aqsa; Haynes, Brittany M; Genson, Allyson M; Hemm, Matthew R

2013-06-07

388

Characterisation of full-length mitochondrial copies and partial nuclear copies (numts) of the cytochrome b and cytochrome c oxidase subunit I genes of Toxoplasma gondii, Neospora caninum, Hammondia heydorni and Hammondia triffittae (Apicomplexa: Sarcocystidae).  

PubMed

Genomic DNA was extracted from three oocyst isolates of Hammondia triffittae from foxes and two oocyst isolates of Hammondia heydorni from dogs, as well as from cell culture-derived tachyzoites of Toxoplasma gondii (RH strain) and Neospora caninum (NC-Liverpool strain), and examined by PCR with primers targeting the cytochrome b (cytb) and the cytochrome c oxidase subunit I (cox1) genes in order to characterise both genes and, if possible, the