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Sample records for cct repeats mediate

  1. Unique CCT repeats mediate transcription of the TWIST1 gene in mesenchymal cell lines

    SciTech Connect

    Ohkuma, Mizue; Funato, Noriko; Higashihori, Norihisa; Murakami, Masanori; Ohyama, Kimie; Nakamura, Masataka . E-mail: naka.gene@cmn.tmd.ac.jp

    2007-01-26

    TWIST1, a basic helix-loop-helix transcription factor, plays critical roles in embryo development, cancer metastasis and mesenchymal progenitor differentiation. Little is known about transcriptional regulation of TWIST1 expression. Here we identified DNA sequences responsible for TWIST1 expression in mesenchymal lineage cell lines. Reporter assays with TWIST1 promoter mutants defined the -102 to -74 sequences that are essential for TWIST1 expression in human and mouse mesenchymal cell lines. Tandem repeats of CCT, but not putative CREB and NF-{kappa}B sites in the sequences substantially supported activity of the TWIST1 promoter. Electrophoretic mobility shift assay demonstrated that the DNA sequences with the CCT repeats formed complexes with nuclear factors, containing, at least, Sp1 and Sp3. These results suggest critical implication of the CCT repeats in association with Sp1 and Sp3 factors in sustaining expression of the TWIST1 gene in mesenchymal cells.

  2. A human microsatellite DNA-mimicking oligodeoxynucleotide with CCT repeats negatively regulates TLR7/9-mediated innate immune responses via selected TLR pathways.

    PubMed

    Sun, Ran; Sun, Luguo; Bao, Musheng; Zhang, Yongsheng; Wang, Li; Wu, Xiuli; Hu, Dali; Liu, Yongjun; Yu, Yongli; Wang, Liying

    2010-03-01

    A human microsatellite DNA-mimicking ODN (MS ODN) composed of CCT repeats, designated as SAT05f, has been studied for its capacity of negatively regulating innate immunity induced by TLR7/TLR9 agonists in vitro and in mice. The result showed that SAT05f could down-regulate TLR7/9-dependent IFN-alpha production in cultured human PBMC stimulated by inactivated Flu virus PR8 or HSV-1 or CpG ODN or imiquimod, protect d-GalN-treated mice from lethal shock induced by TLR9 agonist, not by TLR3/4 agonist. In addition, SAT05f significantly inhibit IFN-alpha production from purified human plasmacytoid cells (pDCs) stimulated by CpG ODN. Interestingly, SAT05f could up-regulate CD80, CD86, and HLA-DR on the pDCs in vitro, implying that SAT05f-mediated inhibition on IFN-alpha production could be related to the activation of pDCs. The data suggest that SAT05f could be developed as a candidate medicament for the treatment of TLR7/9 activation-associated diseases by inhibiting TLR7/9 signaling pathways. PMID:20034855

  3. Methods for sequencing GC-rich and CCT repeat DNA templates

    DOEpatents

    Robinson, Donna L.

    2007-02-20

    The present invention is directed to a PCR-based method of cycle sequencing DNA and other polynucleotide sequences having high CG content and regions of high GC content, and includes for example DNA strands with a high Cytosine and/or Guanosine content and repeated motifs such as CCT repeats.

  4. Chiral Pharmaceutical Intermediaries Obtained by Reduction of 2-Halo-1-(4-substituted phenyl)-ethanones Mediated by Geotrichum candidum CCT 1205 and Rhodotorula glutinis CCT 2182

    PubMed Central

    Fardelone, Lucídio C.; Rodrigues, J. Augusto R.; Moran, Paulo J. S.

    2011-01-01

    Enantioselective reductions of p-R1-C6H4C(O)CH2R2 (R1 = Cl, Br, CH3, OCH3, NO2 and R2 = Br, Cl) mediated by Geotrichum candidum CCT 1205 and Rhodotorula glutinis CCT 2182 afforded the corresponding halohydrins with complementary R and S configurations, respectively, in excellent yield and enantiomeric excesses. The obtained (R)- or (S)-halohydrins are important building blocks in chemical and pharmaceutical industries. PMID:21687613

  5. An oligodeoxynucleotide with CCT repeats restrains CpG ODN-induced TLR9 trafficking.

    PubMed

    Zhang, Xiaoling; Sun, Wei; Wu, Xiuli; Wang, Hua; Yan, Youyou; Guo, Sheng; Song, Dandan; Li, Hainan; Gao, Shuang; Wang, Luowei; Yu, Yongli; Wang, Liying

    2014-01-01

    Toll-like receptor 9 (TLR9) can sense pathogen DNA and CpG ODN or even self-DNA by trafficking assisted by Unc93B1, an endoplasmic reticulum (ER) transmembrane protein, from ER to endolysosomes or cell surface. In previous study, we found that an oligodeoxynucleotide with CCT repeats (SAT05f) could selectively inhibit TLR7/9 activation. However, the mechanism for the inhibitory activity of SAT05f is still unknown. In present research, it was found that SAT05f could inhibit CpG ODN-induced the intracellular trafficking of TLR9 and Unc93B1 with feedback the responses of decreased surface TLR9 and enhanced TLR9 mRNA expression but not influence TLR9 protein level by using human plasmacytoid dendritic cell line CAL-1 cells, suggesting that SAT05f inhibits TLR9 activation by restraining TLR9 trafficking. Since the mitochondrial DNA released from injured tissue can cause systemic inflammatory response syndrome (SIRS), this study may provide valuable data for prevention and treatment of SIRS and rescue severe trauma patients. PMID:25374030

  6. Chaperonin CCT-Mediated AIB1 Folding Promotes the Growth of ERα-Positive Breast Cancer Cells on Hard Substrates

    PubMed Central

    Chen, Li; Zhang, Ze; Qiu, Juhui; Zhang, Lingling; Luo, Xiangdong; Jang, Jun

    2014-01-01

    Clinical observations have revealed a strong association between estrogen receptor alpha (ERα)-positive tumors and the development of bone metastases, however, the mechanism underlying this association remains unknown. We cultured MCF-7 (ERα-positive) on different rigidity substrates. Compared with cells grown on more rigid substrates (100 kPa), cells grown on soft substrates (10 kPa) exhibited reduced spreading ability, a lower ratio of cells in the S and G2/M cell cycle phases, and a decreased proliferation rate. Using stable isotope labeling by amino acids (SILAC), we further compared the whole proteome of MCF-7 cells grown on substrates of different rigidity (10 and 100 kPa), and found that the expression of eight members of chaperonin CCT increased by at least 2-fold in the harder substrate. CCT folding activity was increased in the hard substrate compared with the soft substrates. Amplified in breast cancer 1 (AIB1), was identified in CCT immunoprecipitates. CCT folding ability of AIB1 increased on 100-kPa substrate compared with 10- and 30-kPa substrates. Moreover, using mammalian two-hybrid protein-protein interaction assays, we found that the polyglutamine repeat sequence of the AIB1 protein was essential for interaction between CCTζ and AIB1. CCTζ-mediated AIB1 folding affects the cell area spreading, growth rate, and cell cycle. The expressions of the c-myc, cyclin D1, and PgR genes were higher on hard substrates than on soft substrate in both MCF-7 and T47D cells. ERα and AIB1 could up-regulate the mRNA and protein expression levels of the c-myc, cyclin D1, and PgR genes, and that 17 β-estradiol could enhance this effects. Conversely, 4-hydroxytamoxifen, could inhibit these effects. Taken together, our studies demonstrate that some ERα-positive breast cancer cells preferentially grow on more rigid substrates. CCT-mediated AIB1 folding appears to be involved in the rigidity response of breast cancer cells, which provides novel insight into the

  7. Is Retrieval Mediated after Repeated Testing?

    ERIC Educational Resources Information Center

    Kole, James A.; Healy, Alice F.

    2013-01-01

    In 2 main experiments, the mediated priming effect was used to determine whether retrieval continues to be mediated after repeated testing. In each experiment, participants used the keyword method to learn French vocabulary, then completed a modified lexical decision task in which they first translated a French word, and then made a lexical…

  8. The chicken FMR1 gene is highly conserved with a CCT 5{prime} - untranslated repeat and encodes an RNA-binding protein

    SciTech Connect

    Price, D.K.; Zhang, F.; Ashley, C.T. Jr.; Warren, S.T.

    1996-01-01

    The transcriptional silencing of the human gene, fragile X metal retardation 1 (FMR1), is due to abnormal methylation in response to an expanded 5{prime}-untranslated CGG trinucleotide repeat and accounts for most cases of fragile X syndrome, a frequent inherited form of metal retardation. Although the encoded fragile X mental retardation protein (FMRP) is known to have properties of a RNA-binding protein, the precise function of FMRP remains to be elucidated. We report the cloning of the chicken homolog of FMR1 and show strong evolutionary conservation, with nucleotide and amino acid identities of 85 and 92%, respectively, between chicken and human. In place of the mammalian CGG trinucleotide repeat, a 99-nt tripartite repetitive element containing a CCT trinucleotide repeat flanked on both sides by dinucleotide repeats was identified. Blocks of highly conserved 3{prime}-untranslated sequence were also found. Within the coding region, two copies each of the highly conserved K homology motif and the Arg-Gly-Gly (RGG) box motif, both ribonucleotide particle family domains implicated in RNA binding, were identified. Chicken FMRP was found to bind RNA in vitro, and this activity correlated with the presence of the carboxy-terminal portion of the protein that includes the RGG motifs. 49 refs., 7 figs.

  9. The Chaperonin Containing TCP1 Complex (CCT/TRiC) Is Involved in Mediating Sperm-Oocyte Interaction

    PubMed Central

    Dun, Matthew D.; Smith, Nathan D.; Baker, Mark A.; Lin, Minjie; Aitken, R. John; Nixon, Brett

    2011-01-01

    Sperm-oocyte interactions are among the most remarkable processes in cell biology. These cellular recognition events are initiated by an exquisitely specific adhesion of free-swimming spermatozoa to the zona pellucida, an acellular matrix that surrounds the ovulated oocyte. Decades of research focusing on this interaction have led to the establishment of a widely held paradigm that the zona pellucida receptor is a single molecular entity that is constitutively expressed on the sperm cell surface. In contrast, we have employed the techniques of blue native-polyacrylamide gel electrophoresis, far Western blotting, and proximity ligation to secure the first direct evidence in support of a novel hypothesis that zona binding is mediated by multimeric sperm receptor complex(es). Furthermore, we show that one such multimeric association, comprising the chaperonin-containing TCP1 complex (CCT/TRiC) and a zona-binding protein, zona pellucida-binding protein 2, is present on the surface of capacitated spermatozoa and could account for the zona binding activity of these cells. Collectively, these data provide an important biochemical insight into the molecular basis of sperm-zona pellucida interaction and a plausible explanation for how spermatozoa gain their ability to fertilize. PMID:21880732

  10. GroEL and CCT are catalytic unfoldases mediating out-of-cage polypeptide refolding without ATP.

    PubMed

    Priya, Smriti; Sharma, Sandeep Kumar; Sood, Vishal; Mattoo, Rayees U H; Finka, Andrija; Azem, Abdussalam; De Los Rios, Paolo; Goloubinoff, Pierre

    2013-04-30

    Chaperonins are cage-like complexes in which nonnative polypeptides prone to aggregation are thought to reach their native state optimally. However, they also may use ATP to unfold stably bound misfolded polypeptides and mediate the out-of-cage native refolding of large proteins. Here, we show that even without ATP and GroES, both GroEL and the eukaryotic chaperonin containing t-complex polypeptide 1 (CCT/TRiC) can unfold stable misfolded polypeptide conformers and readily release them from the access ways to the cage. Reconciling earlier disparate experimental observations to ours, we present a comprehensive model whereby following unfolding on the upper cavity, in-cage confinement is not needed for the released intermediates to slowly reach their native state in solution. As over-sticky intermediates occasionally stall the catalytic unfoldase sites, GroES mobile loops and ATP are necessary to dissociate the inhibitory species and regenerate the unfolding activity. Thus, chaperonin rings are not obligate confining antiaggregation cages. They are polypeptide unfoldases that can iteratively convert stable off-pathway conformers into functional proteins. PMID:23584019

  11. GroEL and CCT are catalytic unfoldases mediating out-of-cage polypeptide refolding without ATP

    PubMed Central

    Priya, Smriti; Sharma, Sandeep Kumar; Sood, Vishal; Mattoo, Rayees U. H.; Finka, Andrija; Azem, Abdussalam; De Los Rios, Paolo; Goloubinoff, Pierre

    2013-01-01

    Chaperonins are cage-like complexes in which nonnative polypeptides prone to aggregation are thought to reach their native state optimally. However, they also may use ATP to unfold stably bound misfolded polypeptides and mediate the out-of-cage native refolding of large proteins. Here, we show that even without ATP and GroES, both GroEL and the eukaryotic chaperonin containing t-complex polypeptide 1 (CCT/TRiC) can unfold stable misfolded polypeptide conformers and readily release them from the access ways to the cage. Reconciling earlier disparate experimental observations to ours, we present a comprehensive model whereby following unfolding on the upper cavity, in-cage confinement is not needed for the released intermediates to slowly reach their native state in solution. As over-sticky intermediates occasionally stall the catalytic unfoldase sites, GroES mobile loops and ATP are necessary to dissociate the inhibitory species and regenerate the unfolding activity. Thus, chaperonin rings are not obligate confining antiaggregation cages. They are polypeptide unfoldases that can iteratively convert stable off-pathway conformers into functional proteins. PMID:23584019

  12. OMICS in Ecology: Systems Level Analyses of Halobacterium salinarum Reveal Large-scale Temperature-Mediated Changes and a Requirement of CctA for Thermotolerance

    PubMed Central

    Weng, Rueyhung Roc; Shu, Hung-Wei; Chin, See-Wen; Kao, Yuchieh; Chen, Ting-Wen; Liao, Chen-Chung; Tsay, Yeou-Guang

    2014-01-01

    Abstract Halobacterium salinarum is an extremely halophilic archaeon that inhabits high-salinity aqueous environments in which the temperature can range widely, both daily and seasonally. An OMICS analysis of the 37°C and 49°C proteomes and transcriptomes for revealing the biomodules affected by temperature is reported here. Analysis of those genes/proteins displaying dramatic changes provided a clue to the coordinated changes in the expression of genes within five arCOG biological clusters. When proteins that exhibited minor changes in their spectral counts and insignificant p values were also examined, the apparent influence of the elevated temperatures on conserved chaperones, metabolism, translation, and other biomodules became more obvious. For instance, increases in all eight conserved chaperones and three arginine deiminase pathway enzymes and reductions in most tricarboxylic acid (TCA) cycle enzymes and ribosomal proteins suggest that complex system responses occurred as the temperature changed. When the requirement for the four proteins that showed the greatest induction at 49°C was analyzed, only CctA (chaperonin subunit α), but not Hsp5, DpsA, or VNG1187G, was essential for thermotolerance. Environmental stimuli and other perturbations may induce many minor gene expression changes. Simultaneous analysis of the genes exhibiting dramatic or minor changes in expression may facilitate the detection of systems level responses. PMID:24147786

  13. The role of the Chaperonin containing t-complex polypeptide 1, subunit 8 (CCT8) in B-cell non-Hodgkin's lymphoma.

    PubMed

    Yin, Haibing; Miao, Xiaobing; Wu, Yaxun; Wei, Yingze; Zong, Guijuan; Yang, Shuyun; Chen, Xudong; Zheng, Guihua; Zhu, Xinghua; Guo, Yan; Li, Chunsun; Chen, Yali; Wang, Yuchan; He, Song

    2016-06-01

    The chaperonin containing t-complex polypeptide 1 (CCT) is known to mediate folding of proteins. CCT, subunit 8 (CCT8), is the θ subunit of CCT complex chaperonin. CCT8 has been reported to be dysregulated in several tumor tissues. In this study, we investigated the role of CCT8 in B-cell non-Hodgkin's lymphoma (NHL). Clinically, the expression levels of CCT8 in reactive lymphoid hyperplasia (RLH) and B-cell NHL specimens were investigated using immunohistochemical analysis. We found that CCT8 was highly expressed in proliferating germinal center cells compared with the quiescent cells of the follicular mantle zone. Furthermore, CCT8 was highly expressed in progressive lymphomas than in indolent lymphomas. Kaplan-Meier curve showed that high expression of CCT8 was significantly associated with shorter overall survival in patients with diffuse large B-cell lymphoma. Moreover, we demonstrated that CCT8 could promote the proliferation of B-cell NHL cells. In addition, we found that CCT8 could accelerate the G1/S transition in B-cell NHL. Finally, we demonstrated that overexpression of CCT8 could reverse cell adhesion-mediated drug resistance (CAM-DR) phenotype. Our study may shed new insights into the important role of CCT8 in cancer development. PMID:27101149

  14. CGG repeat-associated translation mediates neurodegeneration in fragile X tremor ataxia syndrome.

    PubMed

    Todd, Peter K; Oh, Seok Yoon; Krans, Amy; He, Fang; Sellier, Chantal; Frazer, Michelle; Renoux, Abigail J; Chen, Kai-chun; Scaglione, K Matthew; Basrur, Venkatesha; Elenitoba-Johnson, Kojo; Vonsattel, Jean P; Louis, Elan D; Sutton, Michael A; Taylor, J Paul; Mills, Ryan E; Charlet-Berguerand, Nicholas; Paulson, Henry L

    2013-05-01

    Fragile X-associated tremor ataxia syndrome (FXTAS) results from a CGG repeat expansion in the 5' UTR of FMR1. This repeat is thought to elicit toxicity as RNA, yet disease brains contain ubiquitin-positive neuronal inclusions, a pathologic hallmark of protein-mediated neurodegeneration. We explain this paradox by demonstrating that CGG repeats trigger repeat-associated non-AUG-initiated (RAN) translation of a cryptic polyglycine-containing protein, FMRpolyG. FMRpolyG accumulates in ubiquitin-positive inclusions in Drosophila, cell culture, mouse disease models, and FXTAS patient brains. CGG RAN translation occurs in at least two of three possible reading frames at repeat sizes ranging from normal (25) to pathogenic (90), but inclusion formation only occurs with expanded repeats. In Drosophila, CGG repeat toxicity is suppressed by eliminating RAN translation and enhanced by increased polyglycine protein production. These studies expand the growing list of nucleotide repeat disorders in which RAN translation occurs and provide evidence that RAN translation contributes to neurodegeneration. PMID:23602499

  15. Conformational modulation mediated by polyglutamine expansion in CAG repeat expansion disease-associated proteins.

    PubMed

    Verani, Margherita; Bustamante, Maria; Martufi, Paola; Daldin, Manuel; Cariulo, Cristina; Azzollini, Lucia; Fodale, Valentina; Puglisi, Francesca; Weiss, Andreas; Macdonald, Douglas; Petricca, Lara; Caricasole, Andrea

    2016-09-16

    We have previously reported TR-FRET based immunoassays to detect a conformational change imparted on huntingtin protein by the polyglutamine expansion, which we confirmed using biophysical methodologies. Using these immunoassays, we now report that polyglutamine expansion influences the conformational properties of other polyglutamine disease proteins, exemplified by the androgen receptor (associated with spinal bulbar muscular atrophy) and TATA binding protein (associated with spinocerebellar ataxia 17). Using artificial constructs bearing short or long polyglutamine expansions or a multimerized, unrelated epitope (mimicking the increase in anti-polyglutamine antibody epitopes present in polyglutamine repeats of increasing length) we confirmed that the conformational TR-FRET based immunoassay detects an intrinsic conformational property of polyglutamine repeats. The TR-FRET based conformational immunoassay may represent a rapid, scalable tool to identify modulators of polyglutamine-mediated conformational change in different proteins associated with CAG triplet repeat disorders. PMID:27520369

  16. A repeatedly refuelable mediated biofuel cell based on a hierarchical porous carbon electrode

    PubMed Central

    Fujita, Shuji; Yamanoi, Shun; Murata, Kenichi; Mita, Hiroki; Samukawa, Tsunetoshi; Nakagawa, Takaaki; Sakai, Hideki; Tokita, Yuichi

    2014-01-01

    Biofuel cells that generate electricity from renewable fuels, such as carbohydrates, must be reusable through repeated refuelling, should these devices be used in consumer electronics. We demonstrate the stable generation of electricity from a glucose-powered mediated biofuel cell through multiple refuelling cycles. This refuelability is achieved by immobilizing nicotinamide adenine dinucleotide (NAD), an electron-transfer mediator, and redox enzymes in high concentrations on porous carbon particles constituting an anode while maintaining their electrochemical and enzymatic activities after the immobilization. This bioanode can be refuelled continuously for more than 60 cycles at 1.5 mA cm−2 without significant potential drop. Cells assembled with these bioanodes and bilirubin-oxidase-based biocathodes can be repeatedly used to power a portable music player at 1 mW cm−3 through 10 refuelling cycles. This study suggests that the refuelability within consumer electronics should facilitate the development of long and repeated use of the mediated biofuel cells as well as of NAD-based biosensors, bioreactors, and clinical applications. PMID:24820210

  17. A repeatedly refuelable mediated biofuel cell based on a hierarchical porous carbon electrode

    NASA Astrophysics Data System (ADS)

    Fujita, Shuji; Yamanoi, Shun; Murata, Kenichi; Mita, Hiroki; Samukawa, Tsunetoshi; Nakagawa, Takaaki; Sakai, Hideki; Tokita, Yuichi

    2014-05-01

    Biofuel cells that generate electricity from renewable fuels, such as carbohydrates, must be reusable through repeated refuelling, should these devices be used in consumer electronics. We demonstrate the stable generation of electricity from a glucose-powered mediated biofuel cell through multiple refuelling cycles. This refuelability is achieved by immobilizing nicotinamide adenine dinucleotide (NAD), an electron-transfer mediator, and redox enzymes in high concentrations on porous carbon particles constituting an anode while maintaining their electrochemical and enzymatic activities after the immobilization. This bioanode can be refuelled continuously for more than 60 cycles at 1.5 mA cm-2 without significant potential drop. Cells assembled with these bioanodes and bilirubin-oxidase-based biocathodes can be repeatedly used to power a portable music player at 1 mW cm-3 through 10 refuelling cycles. This study suggests that the refuelability within consumer electronics should facilitate the development of long and repeated use of the mediated biofuel cells as well as of NAD-based biosensors, bioreactors, and clinical applications.

  18. BRCA2 regulates DMC1-mediated recombination through the BRC repeats

    PubMed Central

    Martinez, Juan S.; von Nicolai, Catharina; Kim, Taeho; Ehlén, Åsa; Mazin, Alexander V.; Kowalczykowski, Stephen C.; Carreira, Aura

    2016-01-01

    In somatic cells, BRCA2 is needed for RAD51-mediated homologous recombination. The meiosis-specific DNA strand exchange protein, DMC1, promotes the formation of DNA strand invasion products (joint molecules) between homologous molecules in a fashion similar to RAD51. BRCA2 interacts directly with both human RAD51 and DMC1; in the case of RAD51, this interaction results in stimulation of RAD51-promoted DNA strand exchange. However, for DMC1, little is known regarding the basis and functional consequences of its interaction with BRCA2. Here we report that human DMC1 interacts directly with each of the BRC repeats of BRCA2, albeit most tightly with repeats 1–3 and 6–8. However, BRC1–3 bind with higher affinity to RAD51 than to DMC1, whereas BRC6–8 bind with higher affinity to DMC1, providing potential spatial organization to nascent filament formation. With the exception of BRC4, each BRC repeat stimulates joint molecule formation by DMC1. The basis for this stimulation is an enhancement of DMC1–ssDNA complex formation by the stimulatory BRC repeats. Lastly, we demonstrate that full-length BRCA2 protein stimulates DMC1-mediated DNA strand exchange between RPA–ssDNA complexes and duplex DNA, thus identifying BRCA2 as a mediator of DMC1 recombination function. Collectively, our results suggest unique and specialized functions for the BRC motifs of BRCA2 in promoting homologous recombination in meiotic and mitotic cells. PMID:26976601

  19. Repeated extinction and reversal learning of an approach response supports an arousal-mediated learning model

    PubMed Central

    Podlesnik, Christopher A.; Sanabria, Federico

    2016-01-01

    We assessed the effects of repeated extinction and reversals of two conditional stimuli (CS+/CS−) on an appetitive conditioned approach response in rats. Three results were observed that could not be accounted for by a simple linear operator model such as the one proposed by Rescorla and Wagner (1972): (1) responding to a CS− declined faster when a CS+ was simultaneously extinguished; (2) reacquisition of pre-extinction performance recovered rapidly within one session; and (3) reversal of CS+/CS− contingencies resulted in a more rapid recovery to the current CS− (former CS+) than the current CS+, accompanied by a slower acquisition of performance to the current CS+. An arousal parameter that mediates learning was introduced to a linear operator model to account for these effects. The arousal-mediated learning model adequately fit the data and predicted data from a second experiment with different rats in which only repeated reversals of CS+/CS− were assessed. According to this arousal-mediated learning model, learning is accelerated by US-elicited arousal and it slows down in the absence of US. Because arousal varies faster than conditioning, the model accounts for the decline in responding during extinction mainly through a reduction in arousal, not a change in learning. By preserving learning during extinction, the model is able to account for relapse effects like rapid reacquisition, renewal, and reinstatement. PMID:21172410

  20. Repeated extinction and reversal learning of an approach response supports an arousal-mediated learning model.

    PubMed

    Podlesnik, Christopher A; Sanabria, Federico

    2011-05-01

    We assessed the effects of repeated extinction and reversals of two conditional stimuli (CS+/CS-) on an appetitive conditioned approach response in rats. Three results were observed that could not be accounted for by a simple linear operator model such as the one proposed by Rescorla and Wagner (1972): (1) responding to a CS- declined faster when a CS+ was simultaneously extinguished; (2) reacquisition of pre-extinction performance recovered rapidly within one session; and (3) reversal of CS+/CS- contingencies resulted in a more rapid recovery to the current CS- (former CS+) than the current CS+, accompanied by a slower acquisition of performance to the current CS+. An arousal parameter that mediates learning was introduced to a linear operator model to account for these effects. The arousal-mediated learning model adequately fit the data and predicted data from a second experiment with different rats in which only repeated reversals of CS+/CS- were assessed. According to this arousal-mediated learning model, learning is accelerated by US-elicited arousal and it slows down in the absence of US. Because arousal varies faster than conditioning, the model accounts for the decline in responding during extinction mainly through a reduction in arousal, not a change in learning. By preserving learning during extinction, the model is able to account for relapse effects like rapid reacquisition, renewal, and reinstatement. PMID:21172410

  1. Evolution of simple sequence repeat-mediated phase variation in bacterial genomes.

    PubMed

    Bayliss, Christopher D; Palmer, Michael E

    2012-09-01

    Mutability as mechanism for rapid adaptation to environmental challenge is an alluringly simple concept whose apotheosis is realized in simple sequence repeats (SSR). Bacterial genomes of several species contain SSRs with a proven role in adaptation to environmental fluctuations. SSRs are hypermutable and generate reversible mutations in localized regions of bacterial genomes, leading to phase variable ON/OFF switches in gene expression. The application of genetic, bioinformatic, and mathematical/computational modeling approaches are revolutionizing our current understanding of how genomic molecular forces and environmental factors influence SSR-mediated adaptation and led to evolution of this mechanism of localized hypermutation in bacterial genomes. PMID:22954215

  2. A variable homopolymeric G-repeat defines small RNA-mediated posttranscriptional regulation of a chemotaxis receptor in Helicobacter pylori

    PubMed Central

    Pernitzsch, Sandy R.; Tirier, Stephan M.; Beier, Dagmar; Sharma, Cynthia M.

    2014-01-01

    Phase variation of hypermutable simple sequence repeats (SSRs) is a widespread and stochastic mechanism to generate phenotypic variation within a population and thereby contributes to host adaptation of bacterial pathogens. Although several examples of SSRs that affect transcription or coding potential have been reported, we now show that a SSR also impacts small RNA-mediated posttranscriptional regulation. Based on in vitro and in vivo analyses, we demonstrate that a variable homopolymeric G-repeat in the leader of the TlpB chemotaxis receptor mRNA of the human pathogen Helicobacter pylori is directly targeted by a small RNA (sRNA), RepG (Regulator of polymeric G-repeats). Whereas RepG sRNA is highly conserved, the tlpB G-repeat length varies among diverse H. pylori strains, resulting in strain-specific RepG-mediated tlpB regulation. Based on modification of the G-repeat length within one strain, we demonstrate that the G-repeat length determines posttranscriptional regulation and can mediate both repression and activation of tlpB through RepG. In vitro translation assays show that this regulation occurs at the translational level and that RepG influences tlpB translation dependent on the G-repeat length. In contrast to the digital ON–OFF switches through frame-shift mutations within coding sequences, such modulation of posttranscriptional regulation allows for a gradual control of gene expression. This connection to sRNA-mediated posttranscriptional regulation might also apply to other genes with SSRs, which could be targeting sites of cis- or trans-encoded sRNAs, and thereby could facilitate host adaptation through sRNA-mediated fine-tuning of virulence gene expression. PMID:24474799

  3. Tetratricopeptide repeat factor XAB2 mediates the end resection step of homologous recombination.

    PubMed

    Onyango, David O; Howard, Sean M; Neherin, Kashfia; Yanez, Diana A; Stark, Jeremy M

    2016-07-01

    We examined the influence of the tetratricopeptide repeat factor XAB2 on chromosomal break repair, and found that XAB2 promotes end resection that generates the 3' ssDNA intermediate for homologous recombination (HR). Namely, XAB2 is important for chromosomal double-strand break (DSB) repair via two pathways of HR that require end resection as an intermediate step, end resection of camptothecin (Cpt)-induced DNA damage, and RAD51 recruitment to ionizing radiation induced foci (IRIF), which requires end resection. Furthermore, XAB2 mediates specific aspects of the DNA damage response associated with end resection proficiency: CtIP hyperphosphorylation induced by Cpt and BRCA1 IRIF. XAB2 also promotes histone acetylation events linked to HR proficiency. From truncation mutation analysis, the capacity for XAB2 to promote HR correlates with its ability to form a complex with ISY1 and PRP19, which show a similar influence as XAB2 on HR. This XAB2 complex localizes to punctate structures consistent with interchromatin granules that show a striking adjacent-localization to the DSB marker γH2AX. In summary, we suggest that the XAB2 complex mediates DNA damage response events important for the end resection step of HR, and speculate that its adjacent-localization relative to DSBs marked by γH2AX is important for this function. PMID:27084940

  4. Tetratricopeptide repeat factor XAB2 mediates the end resection step of homologous recombination

    PubMed Central

    Onyango, David O.; Howard, Sean M.; Neherin, Kashfia; Yanez, Diana A.; Stark, Jeremy M.

    2016-01-01

    We examined the influence of the tetratricopeptide repeat factor XAB2 on chromosomal break repair, and found that XAB2 promotes end resection that generates the 3′ ssDNA intermediate for homologous recombination (HR). Namely, XAB2 is important for chromosomal double-strand break (DSB) repair via two pathways of HR that require end resection as an intermediate step, end resection of camptothecin (Cpt)-induced DNA damage, and RAD51 recruitment to ionizing radiation induced foci (IRIF), which requires end resection. Furthermore, XAB2 mediates specific aspects of the DNA damage response associated with end resection proficiency: CtIP hyperphosphorylation induced by Cpt and BRCA1 IRIF. XAB2 also promotes histone acetylation events linked to HR proficiency. From truncation mutation analysis, the capacity for XAB2 to promote HR correlates with its ability to form a complex with ISY1 and PRP19, which show a similar influence as XAB2 on HR. This XAB2 complex localizes to punctate structures consistent with interchromatin granules that show a striking adjacent-localization to the DSB marker γH2AX. In summary, we suggest that the XAB2 complex mediates DNA damage response events important for the end resection step of HR, and speculate that its adjacent-localization relative to DSBs marked by γH2AX is important for this function. PMID:27084940

  5. Clean coal technologies---An international seminar: Seminar evaluation and identification of potential CCT markets

    SciTech Connect

    Guziel, K.A.; Poch, L.A.; Gillette, J.L.; Buehring, W.A.

    1991-07-01

    The need for environmentally responsible electricity generation is a worldwide concern. Because coal is available throughout the world at a reasonable cost, current research is focusing on technologies that use coal with minimal environmental effects. The United States government is supporting research on clean coal technologies (CCTs) to be used for new capacity additions and for retrofits to existing capacity. To promote the worldwide adoption of US CCTs, the US Department of Energy, the US Agency for International Development, and the US Trade and Development Program sponsored a two-week seminar titled Clean Coal Technologies -- An International Seminar. Nineteen participants from seven countries were invited to this seminar, which was held at Argonne National Laboratory in June 1991. During the seminar, 11 US CCT vendors made presentations on their state-of-the-art and commercially available technologies. The presentations included technical, environmental, operational, and economic characteristics of CCTs. Information on financing and evaluating CCTs also was presented, and participants visited two CCT operating sites. The closing evaluation indicated that the seminar was a worthwhile experience for all participants and that it should be repeated. The participants said CCT could play a role in their existing and future electric capacity, but they agreed that more CCT demonstration projects were needed to confirm the reliability and performance of the technologies.

  6. CCT241533 is a potent and selective inhibitor of CHK2 which potentiates the cytotoxicity of PARP inhibitors

    PubMed Central

    Anderson, Victoria E; Walton, Michael I; Eve, Paul D; Boxall, Katherine J; Antoni, Laurent; Caldwell, John J; Pearl, Laurence H; Oliver, Antony W; Collins, Ian; Garrett, Michelle D

    2016-01-01

    CHK2 is a checkpoint kinase involved in the ATM-mediated response to double strand DNA breaks. Its potential as a drug target is still unclear but inhibitors of CHK2 may increase the efficacy of genotoxic cancer therapies in a p53 mutant background by eliminating one of the checkpoints or DNA repair pathways contributing to cellular resistance. We report here the identification and characterization of a novel CHK2 kinase inhibitor, CCT241533. X-ray crystallography confirmed that CCT241533 bound to CHK2 in the ATP pocket. This compound inhibits CHK2 with an IC50 of 3 nM and shows minimal cross reactivity against a panel of kinases at 1 μM. CCT241533 blocked CHK2 activity in human tumor cell lines in response to DNA damage, as demonstrated by inhibition of CHK2 autophosphorylation at S516, band-shift mobility changes and HDMX degradation. CCT241533 did not potentiate the cytotoxicity of a selection of genotoxic agents in several cell lines. However, this compound significantly potentiates the cytotoxicity of two structurally distinct Poly (ADP-ribose) polymerase (PARP) inhibitors. Clear induction of the pS516 CHK2 signal was seen with a PARP inhibitor alone and this activation was abolished by CCT241533, implying that the potentiation of PARP inhibitor cell killing by CCT241533 was due to inhibition of CHK2. Consequently CHK2 inhibitors may have therapeutic activity in combination with PARP inhibitors. PMID:21239475

  7. Structural Mechanisms of Mutant Huntingtin Aggregation Suppression by the Synthetic Chaperonin-like CCT5 Complex Explained by Cryoelectron Tomography*

    PubMed Central

    Darrow, Michele C.; Sergeeva, Oksana A.; Isas, Jose M.; Galaz-Montoya, Jesús G.; King, Jonathan A.; Langen, Ralf; Schmid, Michael F.; Chiu, Wah

    2015-01-01

    Huntington disease, a neurodegenerative disorder characterized by functional deficits and loss of striatal neurons, is linked to an expanded and unstable CAG trinucleotide repeat in the huntingtin gene (HTT). This DNA sequence translates to a polyglutamine repeat in the protein product, leading to mutant huntingtin (mHTT) protein aggregation. The aggregation of mHTT is inhibited in vitro and in vivo by the TCP-1 ring complex (TRiC) chaperonin. Recently, a novel complex comprised of a single type of TRiC subunit has been reported to inhibit mHTT aggregation. Specifically, the purified CCT5 homo-oligomer complex, when compared with TRiC, has a similar structure, ATP use, and substrate refolding activity, and, importantly, it also inhibits mHTT aggregation. Using an aggregation suppression assay and cryoelectron tomography coupled with a novel computational classification method, we uncover the interactions between the synthetic CCT5 complex (∼1 MDa) and aggregates of mutant huntingtin exon 1 containing 46 glutamines (mHTTQ46-Ex1). We find that, in a similar fashion to TRiC, synthetic CCT5 complex caps mHTT fibrils at their tips and encapsulates mHTT oligomers, providing a structural description of the inhibition of mHTTQ46-Ex1 by CCT5 complex and a shared mechanism of mHTT inhibition between TRiC chaperonin and the CCT5 complex: cap and contain. PMID:25995452

  8. Structural Mechanisms of Mutant Huntingtin Aggregation Suppression by the Synthetic Chaperonin-like CCT5 Complex Explained by Cryoelectron Tomography.

    PubMed

    Darrow, Michele C; Sergeeva, Oksana A; Isas, Jose M; Galaz-Montoya, Jesús G; King, Jonathan A; Langen, Ralf; Schmid, Michael F; Chiu, Wah

    2015-07-10

    Huntington disease, a neurodegenerative disorder characterized by functional deficits and loss of striatal neurons, is linked to an expanded and unstable CAG trinucleotide repeat in the huntingtin gene (HTT). This DNA sequence translates to a polyglutamine repeat in the protein product, leading to mutant huntingtin (mHTT) protein aggregation. The aggregation of mHTT is inhibited in vitro and in vivo by the TCP-1 ring complex (TRiC) chaperonin. Recently, a novel complex comprised of a single type of TRiC subunit has been reported to inhibit mHTT aggregation. Specifically, the purified CCT5 homo-oligomer complex, when compared with TRiC, has a similar structure, ATP use, and substrate refolding activity, and, importantly, it also inhibits mHTT aggregation. Using an aggregation suppression assay and cryoelectron tomography coupled with a novel computational classification method, we uncover the interactions between the synthetic CCT5 complex (∼ 1 MDa) and aggregates of mutant huntingtin exon 1 containing 46 glutamines (mHTTQ46-Ex1). We find that, in a similar fashion to TRiC, synthetic CCT5 complex caps mHTT fibrils at their tips and encapsulates mHTT oligomers, providing a structural description of the inhibition of mHTTQ46-Ex1 by CCT5 complex and a shared mechanism of mHTT inhibition between TRiC chaperonin and the CCT5 complex: cap and contain. PMID:25995452

  9. LGSOWG CCT format CCB document: The standard CCT family of tape formats

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The tape format standardization approach recommended by the committee on CCT standardization is described and defined. All rules and conventions required to employ the superstructure approach to the CCT family of tape formats are presented for users of remote sensing data and producer of user tapes and the superstructure records are specified. The standard for future tape format design is presented as a guide to designing data records of a particular tape format. An example is provided showing how to incorporate the superstructure into an already established tape format.

  10. User's guide for CCT2WA (converting CCT's to work-addressable file)

    NASA Technical Reports Server (NTRS)

    Williams, S. D.; Hackler, D. B.

    1981-01-01

    The CCT2WA program, developed to convert the shuttle post-flight computer compatible tape data to a word addressable mass storage file, is described. The use of utility processors that can be used to copy word addressable files from mass storage to mass storage is also described.

  11. Epidermal growth factor-like repeats mediate lateral and reciprocal interactions of Ep-CAM molecules in homophilic adhesions.

    PubMed

    Balzar, M; Briaire-de Bruijn, I H; Rees-Bakker, H A; Prins, F A; Helfrich, W; de Leij, L; Riethmüller, G; Alberti, S; Warnaar, S O; Fleuren, G J; Litvinov, S V

    2001-04-01

    Ep-CAM is a new type of cell adhesion molecule (CAM) which does not structurally resemble the members of the four major families (cadherins, integrins, selectins, and CAMs of the immunoglobulin superfamily) and mediates Ca(2+)-independent, homophilic adhesions. The extracellular domain of Ep-CAM consists of a cysteine-rich region, containing two type II epidermal growth factor (EGF)-like repeats, followed by a cysteine-poor region. We generated mutated Ep-CAM forms with various deletions in the extracellular domain. These deletion mutants, together with monoclonal antibodies recognizing different epitopes in the extracellular domain, were used to investigate the role of the EGF-like repeats in the formation of intercellular contacts mediated by Ep-CAM molecules. We established that both EGF-like repeats are required for the formation of Ep-CAM-mediated homophilic adhesions, including the accumulation of Ep-CAM molecules at the cell-cell boundaries, and the anchorage of the Ep-CAM adhesion complex to F-actin via alpha-actinin. Deletion of either EGF-like repeat was sufficient to inhibit the adhesion properties of the molecule. The first EGF-like repeat of Ep-CAM is required for reciprocal interactions between Ep-CAM molecules on adjacent cells, as was demonstrated with blocking antibodies. The second EGF-like repeat was mainly required for lateral interactions between Ep-CAM molecules. Lateral interactions between Ep-CAM molecules result in the formation of tetramers, which might be the first and necessary step in the formation of Ep-CAM-mediated intercellular contacts. PMID:11259604

  12. Epidermal Growth Factor-Like Repeats Mediate Lateral and Reciprocal Interactions of Ep-CAM Molecules in Homophilic Adhesions

    PubMed Central

    Balzar, M.; Briaire-de Bruijn, I. H.; Rees-Bakker, H. A. M.; Prins, F. A.; Helfrich, W.; de Leij, L.; Riethmüller, G.; Alberti, S.; Warnaar, S. O.; Fleuren, G. J.; Litvinov, S. V.

    2001-01-01

    Ep-CAM is a new type of cell adhesion molecule (CAM) which does not structurally resemble the members of the four major families (cadherins, integrins, selectins, and CAMs of the immunoglobulin superfamily) and mediates Ca2+-independent, homophilic adhesions. The extracellular domain of Ep-CAM consists of a cysteine-rich region, containing two type II epidermal growth factor (EGF)-like repeats, followed by a cysteine-poor region. We generated mutated Ep-CAM forms with various deletions in the extracellular domain. These deletion mutants, together with monoclonal antibodies recognizing different epitopes in the extracellular domain, were used to investigate the role of the EGF-like repeats in the formation of intercellular contacts mediated by Ep-CAM molecules. We established that both EGF-like repeats are required for the formation of Ep-CAM-mediated homophilic adhesions, including the accumulation of Ep-CAM molecules at the cell-cell boundaries, and the anchorage of the Ep-CAM adhesion complex to F-actin via α-actinin. Deletion of either EGF-like repeat was sufficient to inhibit the adhesion properties of the molecule. The first EGF-like repeat of Ep-CAM is required for reciprocal interactions between Ep-CAM molecules on adjacent cells, as was demonstrated with blocking antibodies. The second EGF-like repeat was mainly required for lateral interactions between Ep-CAM molecules. Lateral interactions between Ep-CAM molecules result in the formation of tetramers, which might be the first and necessary step in the formation of Ep-CAM-mediated intercellular contacts. PMID:11259604

  13. Biochemical Characterization of Mutants in Chaperonin Proteins CCT4 and CCT5 Associated with Hereditary Sensory Neuropathy*

    PubMed Central

    Sergeeva, Oksana A.; Tran, Meme T.; Haase-Pettingell, Cameron; King, Jonathan A.

    2014-01-01

    Hereditary sensory neuropathies are a class of disorders marked by degeneration of the nerve fibers in the sensory periphery neurons. Recently, two mutations were identified in the subunits of the eukaryotic cytosolic chaperonin TRiC, a protein machine responsible for folding actin and tubulin in the cell. C450Y CCT4 was identified in a stock of Sprague-Dawley rats, whereas H147R CCT5 was found in a human Moroccan family. As with many genetically identified mutations associated with neuropathies, the underlying molecular basis of the mutants was not defined. We investigated the biochemical properties of these mutants using an expression system in Escherichia coli that produces homo-oligomeric rings of CCT4 and CCT5. Full-length versions of both mutant protein chains were expressed in E. coli at levels approaching that of the WT chains. Sucrose gradient centrifugation revealed chaperonin-sized complexes of both WT and mutant chaperonins, but with reduced recovery of C450Y CCT4 soluble subunits. Electron microscopy of negatively stained samples of C450Y CCT4 revealed few ring-shaped species, whereas WT CCT4, H147R CCT5, and WT CCT5 revealed similar ring structures. CCT5 complexes were assayed for their ability to suppress aggregation of and refold the model substrate γd-crystallin, suppress aggregation of mutant huntingtin, and refold the physiological substrate β-actin in vitro. H147R CCT5 was not as efficient in chaperoning these substrates as WT CCT5. The subtle effects of these mutations are consistent with the homozygous disease phenotype, in which most functions are carried out during development and adulthood, but some selective function is lost or reduced. PMID:25124038

  14. Development of CCT in the Chinese power industry

    SciTech Connect

    Jiang Zhesheng; Jiang Minhua

    1994-12-31

    This paper briefly describes the present situation of coal related pollution caused by utility boilers in China and the present status of development and application of CCT in Chinese power plants. The paper also introduces strategies to deal with the coal related pollution and predicts future prospects of CCT application.

  15. CONSOL`s perspective on CCT deployment

    SciTech Connect

    Burke, F.P.; Statnick, R.M.

    1997-12-31

    The principal focus of government investment in Clean Coal Technology must be to serve the interests of the US energy consumer. Because of its security of supply and low cost, coal will continue to be the fuel of choice in the existing domestic electricity generating market. The ability of coal to compete for new generating capacity will depend largely on natural gas prices and the efficiency of coal and gas-fired generating options. Furthermore, potential environmental regulations, coupled with utility deregulation, create a climate of economic uncertainty that may limit future investment decisions favorable to coal. Therefore, the federal government, through programs such as CCT, should promote the development of greenfield and retrofit coal use technology that improves generating efficiency and meets environmental requirements for the domestic electric market.

  16. A human CCT5 gene mutation causing distal neuropathy impairs hexadecamer assembly in an archaeal model

    PubMed Central

    Min, Wonki; Angileri, Francesca; Luo, Haibin; Lauria, Antonino; Shanmugasundaram, Maruda; Almerico, Anna Maria; Cappello, Francesco; de Macario, Everly Conway; Lednev, Igor K.; Macario, Alberto J. L.; Robb, Frank T.

    2014-01-01

    Chaperonins mediate protein folding in a cavity formed by multisubunit rings. The human CCT has eight non-identical subunits and the His147Arg mutation in one subunit, CCT5, causes neuropathy. Knowledge is scarce on the impact of this and other mutations upon the chaperone's structure and functions. To make progress, experimental models must be developed. We used an archaeal mutant homolog and demonstrated that the His147Arg mutant has impaired oligomeric assembly, ATPase activity, and defective protein homeostasis functions. These results establish for the first time that a human chaperonin gene defect can be reproduced and studied at the molecular level with an archaeal homolog. The major advantage of the system, consisting of rings with eight identical subunits, is that it amplifies the effects of a mutation as compared with the human counterpart, in which just one subunit per ring is defective. Therefore, the slight deficit of a non-lethal mutation can be detected and characterized. PMID:25345891

  17. CCT WG8 CMC Review Protocols: Development and Implementation

    NASA Astrophysics Data System (ADS)

    Strouse, G. F.; Ballico, M.; Bojkovski, J.; de Groot, M.; Liedberg, H. G.; Pokhodun, A. I.

    2008-06-01

    The primary objectives of the Consultative Committee on Thermometry Working Group 8 (CCT WG8) are to establish and maintain lists of service categories, to agree on detailed technical review criteria of submitted calibration and measurement capabilities (CMCs), and, where necessary, to develop rules for the preparation of CMC entries. One of the main tasks of CCT WG8 is the creation of harmonized CMC review protocols for thermometry and humidity that are scientifically based. The work of CCT WG8 is performed by the Regional Metrology Organization (RMO) Working Group on Thermometry chairpersons and invited technical experts. The CCT WG8 develops practical, pragmatic guidelines for CMC reviews that let the CMC review process proceed according to a set of objective numerical criteria and specified technical evidence to reduce the possibility of disagreement. The CCT WG8 CMC review protocols are designed so that CMC reviews are scientifically based and not designed to bluntly increase uncertainties. The CMC review protocols currently developed and accepted by CCT WG8 cover International Temperature Scale of 1990 (ITS-90) fixed-point cells, ITS-90 calibration temperature subranges for standard platinum resistance thermometers, industrial thermometers, radiation thermometry, and humidity. This article describes the methods used by the CCT WG8 committee to create the review protocols.

  18. CREB Binding Protein Interacts with Nucleoporin-Specific FG Repeats That Activate Transcription and Mediate NUP98-HOXA9 Oncogenicity

    PubMed Central

    Kasper, Lawryn H.; Brindle, Paul K.; Schnabel, Catherine A.; Pritchard, Colin E. J.; Cleary, Michael L.; van Deursen, Jan M. A.

    1999-01-01

    Genes encoding the Phe-Gly (FG) repeat-containing nucleoporins NUP98 and CAN/NUP214 are at the breakpoints of several chromosomal translocations associated with human acute myeloid leukemia (AML), but their role in oncogenesis is unclear. Here we demonstrate that the NUP98-HOXA9 fusion gene encodes two nuclear oncoproteins with either 19 or 37 NUP98 FG repeats fused to the DNA binding and PBX heterodimerization domains of the transcription factor HOXA9. Both NUP98-HOXA9 chimeras transformed NIH 3T3 fibroblasts, and this transformation required the HOXA9 domains for DNA binding and PBX interaction. Surprisingly, the FG repeats acted as very potent transactivators of gene transcription. This NUP98-derived activity is essential for transformation and can be replaced by the bona fide transactivation domain of VP16. Interestingly, FG repeat-containing segments derived from the nucleoporins NUP153 and CAN/NUP214 functioned similarly to those from NUP98. We further demonstrate that transactivation by FG repeat-rich segments of NUP98 correlates with their ability to interact functionally and physically with the transcriptional coactivators CREB binding protein (CBP) and p300. This finding shows, for the first time, that a translocation-generated fusion protein appears to recruit CBP/p300 as an important step of its oncogenic mechanism. Together, our results suggest that NUP98-HOXA9 chimeras are aberrant transcription factors that deregulate HOX-responsive genes through the transcriptional activation properties of nucleoporin-specific FG repeats that recruit CBP/p300. Indeed, FG repeat-mediated transactivation may be a shared pathogenic function of nucleoporins implicated human AML. PMID:9858599

  19. Repeat-mediated genetic and epigenetic changes at the FMR1 locus in the Fragile X-related disorders

    PubMed Central

    Usdin, Karen; Hayward, Bruce E.; Kumari, Daman; Lokanga, Rachel A.; Sciascia, Nicholas; Zhao, Xiao-Nan

    2014-01-01

    The Fragile X-related disorders are a group of genetic conditions that include the neurodegenerative disorder, Fragile X-associated tremor/ataxia syndrome (FXTAS), the fertility disorder, Fragile X-associated primary ovarian insufficiency (FXPOI) and the intellectual disability, Fragile X syndrome (FXS). The pathology in all these diseases is related to the number of CGG/CCG-repeats in the 5′ UTR of the Fragile X mental retardation 1 (FMR1) gene. The repeats are prone to continuous expansion and the increase in repeat number has paradoxical effects on gene expression increasing transcription on mid-sized alleles and decreasing it on longer ones. In some cases the repeats can simultaneously both increase FMR1 mRNA production and decrease the levels of the FMR1 gene product, Fragile X mental retardation 1 protein (FMRP). Since FXTAS and FXPOI result from the deleterious consequences of the expression of elevated levels of FMR1 mRNA and FXS is caused by an FMRP deficiency, the clinical picture is turning out to be more complex than once appreciated. Added complications result from the fact that increasing repeat numbers make the alleles somatically unstable. Thus many individuals have a complex mixture of different sized alleles in different cells. Furthermore, it has become apparent that the eponymous fragile site, once thought to be no more than a useful diagnostic criterion, may have clinical consequences for females who inherit chromosomes that express this site. This review will cover what is currently known about the mechanisms responsible for repeat instability, for the repeat-mediated epigenetic changes that affect expression of the FMR1 gene, and for chromosome fragility. It will also touch on what current and future options are for ameliorating some of these effects. PMID:25101111

  20. KTKEGV repeat motifs are key mediators of normal α-synuclein tetramerization: Their mutation causes excess monomers and neurotoxicity

    PubMed Central

    Dettmer, Ulf; Newman, Andrew J.; von Saucken, Victoria E.; Bartels, Tim; Selkoe, Dennis

    2015-01-01

    α-Synuclein (αS) is a highly abundant neuronal protein that aggregates into β-sheet–rich inclusions in Parkinson’s disease (PD). αS was long thought to occur as a natively unfolded monomer, but recent work suggests it also occurs normally in α-helix–rich tetramers and related multimers. To elucidate the fundamental relationship between αS multimers and monomers in living neurons, we performed systematic mutagenesis to abolish self-interactions and learn which structural determinants underlie native multimerization. Unexpectedly, tetramers/multimers still formed in cells expressing each of 14 sequential 10-residue deletions across the 140-residue polypeptide. We postulated compensatory effects among the six highly conserved and one to three additional αS repeat motifs (consensus: KTKEGV), consistent with αS and its homologs β- and γ-synuclein all forming tetramers while sharing only the repeats. Upon inserting in-register missense mutations into six or more αS repeats, certain mutations abolished tetramer formation, shown by intact-cell cross-linking and independently by fluorescent-protein complementation. For example, altered repeat motifs KLKEGV, KTKKGV, KTKEIV, or KTKEGW did not support tetramerization, indicating the importance of charged or small residues. When we expressed numerous different in-register repeat mutants in human neural cells, all multimer-abolishing but no multimer-neutral mutants caused frank neurotoxicity akin to the proapoptotic protein Bax. The multimer-abolishing variants became enriched in buffer-insoluble cell fractions and formed round cytoplasmic inclusions in primary cortical neurons. We conclude that the αS repeat motifs mediate physiological tetramerization, and perturbing them causes PD-like neurotoxicity. Moreover, the mutants we describe are valuable tools for studying normal and pathological properties of αS and screening for tetramer-stabilizing therapeutics. PMID:26153422

  1. Astronaut Allen during extravehicular activity (EVA) training in CCT

    NASA Technical Reports Server (NTRS)

    1993-01-01

    In the JSC Space Vehicle Mockup Facility, astronaut Andrew M. Allen retrieves gear to rehearse a suit-donning exercise on the middeck. Allen's very realistic environs are provided by the shuttle crew compartment trainer (CCT).

  2. Recombination of a 3-chlorobenzoate catabolic plasmid from Alcaligenes eutrophus NH9 mediated by direct repeat elements.

    PubMed

    Ogawa, N; Miyashita, K

    1995-11-01

    Alcaligenes eutrophus NH9 was isolated from soil. This strain can utilize 3-chlorobenzoate (3-CB) as a sole source of carbon and energy. Most of the 3-CB-negative segregants had lost one of the plasmids present in the parent strain. The genes for catabolism of 3-CB were located within a 9.2-kb SacI fragment of this plasmid (pENH91). The genes were found to hybridize with genes for components of the modified ortho cleavage pathway from Pseudomonas putida. In one of the 3-CB-negative segregants, the plasmid had undergone the deletion of a segment with a size of about 12.5 kb that covered the catabolic genes. The deletion event seemed to be the result of reciprocal recombination between two highly homologous sequences with sizes of 2.5 kb that were present as a direct repeat at the two ends of the region that included the catabolic genes. Nucleotide sequence analysis of homologous fragments revealed a structure that resembled an insertion sequence and relatedness to IS21. During repeated subculturing of NH9 on liquid media with 3-CB, the culture was taken over by a derivative strain (designated NH9A) in which the degradative plasmid carried a duplicate copy of the 12.5-kb region that contained the catabolic genes. The duplication of these genes seemed again to have been mediated by recombination between the direct repeat sequences. PMID:8526487

  3. Induction of HIV-1 long terminal repeat-mediated transcription by Neisseria gonorrhoeae.

    PubMed

    Chen, Adrienne; Boulton, Ian C; Pongoski, Jodi; Cochrane, Alan; Gray-Owen, Scott D

    2003-03-01

    Gonorrhoea enhances the transmission of HIV through increased viral shedding and the increased probability of seroconversion among previously HIV-negative individuals. However, the mechanism(s) underlying these influences remain poorly understood. We demonstrated that exposure to Neisseria gonorrhoeae induces the nuclear factor kappa B-dependent transcription from the HIV-1 long terminal repeat in derivatives of the Jurkat CD4 T cell line. These data suggest that gonococcal infection directly impacts HIV-1 transmission through the localized stimulation of viral expression. PMID:12598784

  4. Mechanism of Copper Mediated Triple Helix Formation at Neutral pH in Drosophila Satellite Repeats

    PubMed Central

    Paris, C.; Geinguenaud, F.; Gouyette, C.; Liquier, J.; Lacoste, J.

    2007-01-01

    The highly repeated Drosophila melanogaster AAGAGAG satellite sequence is present at each chromosome centromere of the fly. We demonstrate here how, under nearly physiological pH conditions, these sequences can form a pyrimidine triple helix containing T·A-T and CCu·G-C base triplets, stabilized by Cu2+ metal ions in amounts mirroring in vivo concentrations. Ultraviolet experiments were used to monitor the triple helix formation at pH 7.2 in presence of Cu2+ ions. Triplex melting is observed at 23°C. Furthermore, a characteristic signature of triple helix formation was obtained by Fourier transform infrared spectroscopy. The stabilization of the C·G-C base triplets at pH 7.2 is shown to occur via interactions of Cu2+ ions on the third strand cytosine N3 atom and on the guanine N7 atom of the polypurine target strand forming CCu·G-C triplets. Under the same neutral pH conditions in absence of Cu2+ ions, the triple helix fails to form. Possible biological implications are discussed. PMID:17208971

  5. Validation and genotyping of multiple human polymorphic inversions mediated by inverted repeats reveals a high degree of recurrence.

    PubMed

    Aguado, Cristina; Gayà-Vidal, Magdalena; Villatoro, Sergi; Oliva, Meritxell; Izquierdo, David; Giner-Delgado, Carla; Montalvo, Víctor; García-González, Judit; Martínez-Fundichely, Alexander; Capilla, Laia; Ruiz-Herrera, Aurora; Estivill, Xavier; Puig, Marta; Cáceres, Mario

    2014-03-01

    In recent years different types of structural variants (SVs) have been discovered in the human genome and their functional impact has become increasingly clear. Inversions, however, are poorly characterized and more difficult to study, especially those mediated by inverted repeats or segmental duplications. Here, we describe the results of a simple and fast inverse PCR (iPCR) protocol for high-throughput genotyping of a wide variety of inversions using a small amount of DNA. In particular, we analyzed 22 inversions predicted in humans ranging from 5.1 kb to 226 kb and mediated by inverted repeat sequences of 1.6-24 kb. First, we validated 17 of the 22 inversions in a panel of nine HapMap individuals from different populations, and we genotyped them in 68 additional individuals of European origin, with correct genetic transmission in ∼ 12 mother-father-child trios. Global inversion minor allele frequency varied between 1% and 49% and inversion genotypes were consistent with Hardy-Weinberg equilibrium. By analyzing the nucleotide variation and the haplotypes in these regions, we found that only four inversions have linked tag-SNPs and that in many cases there are multiple shared SNPs between standard and inverted chromosomes, suggesting an unexpected high degree of inversion recurrence during human evolution. iPCR was also used to check 16 of these inversions in four chimpanzees and two gorillas, and 10 showed both orientations either within or between species, providing additional support for their multiple origin. Finally, we have identified several inversions that include genes in the inverted or breakpoint regions, and at least one disrupts a potential coding gene. Thus, these results represent a significant advance in our understanding of inversion polymorphism in human populations and challenge the common view of a single origin of inversions, with important implications for inversion analysis in SNP-based studies. PMID:24651690

  6. Validation and Genotyping of Multiple Human Polymorphic Inversions Mediated by Inverted Repeats Reveals a High Degree of Recurrence

    PubMed Central

    Aguado, Cristina; Gayà-Vidal, Magdalena; Villatoro, Sergi; Oliva, Meritxell; Izquierdo, David; Giner-Delgado, Carla; Montalvo, Víctor; García-González, Judit; Martínez-Fundichely, Alexander; Capilla, Laia; Ruiz-Herrera, Aurora; Estivill, Xavier; Puig, Marta; Cáceres, Mario

    2014-01-01

    In recent years different types of structural variants (SVs) have been discovered in the human genome and their functional impact has become increasingly clear. Inversions, however, are poorly characterized and more difficult to study, especially those mediated by inverted repeats or segmental duplications. Here, we describe the results of a simple and fast inverse PCR (iPCR) protocol for high-throughput genotyping of a wide variety of inversions using a small amount of DNA. In particular, we analyzed 22 inversions predicted in humans ranging from 5.1 kb to 226 kb and mediated by inverted repeat sequences of 1.6–24 kb. First, we validated 17 of the 22 inversions in a panel of nine HapMap individuals from different populations, and we genotyped them in 68 additional individuals of European origin, with correct genetic transmission in ∼12 mother-father-child trios. Global inversion minor allele frequency varied between 1% and 49% and inversion genotypes were consistent with Hardy-Weinberg equilibrium. By analyzing the nucleotide variation and the haplotypes in these regions, we found that only four inversions have linked tag-SNPs and that in many cases there are multiple shared SNPs between standard and inverted chromosomes, suggesting an unexpected high degree of inversion recurrence during human evolution. iPCR was also used to check 16 of these inversions in four chimpanzees and two gorillas, and 10 showed both orientations either within or between species, providing additional support for their multiple origin. Finally, we have identified several inversions that include genes in the inverted or breakpoint regions, and at least one disrupts a potential coding gene. Thus, these results represent a significant advance in our understanding of inversion polymorphism in human populations and challenge the common view of a single origin of inversions, with important implications for inversion analysis in SNP-based studies. PMID:24651690

  7. Increased CCT-eta expression is a marker of latent and active disease and a modulator of fibroblast contractility in Dupuytren's contracture.

    PubMed

    Satish, Latha; O'Gorman, David B; Johnson, Sandra; Raykha, Christina; Gan, Bing Siang; Wang, James H-C; Kathju, Sandeep

    2013-07-01

    Dupuytren's contracture (DC) is a fibroproliferative disorder of unknown etiology characterized by a scar-like contracture that develops in the palm and/or digits. We have previously reported that the eta subunit of the chaperonin containing T-complex polypeptide (CCT-eta) is increased in fibrotic wound healing, and is essential for the accumulation of α-smooth muscle actin (α-SMA) in fibroblasts. The purpose of this study was to determine if CCT-eta is similarly implicated in the aberrant fibrosis seen in DC and to investigate the role of CCT-eta in the behavior of myo/fibroblasts in DC. Fibroblasts were obtained from DC-affected palmar fascia, from adjacent phenotypically normal palmar fascia in the same DC patients (PF), and from non-DC palmar fascial tissues in patients undergoing carpal tunnel (CT) release. Inherent contractility in these three populations was examined using fibroblast-populated collagen lattices (FPCLs) and by cell traction force microscopy. Expression of CCT-eta and α-SMA protein was determined by Western blot. The effect of CCT-eta inhibition on the contractility of DC cells was determined by deploying an siRNA versus CCT-eta. DC cells were significantly more contractile than both matching palmar fascial (PF) cells and CT cells in both assays, with PF cells demonstrating an intermediate contractility in the FPCL assay. Whereas α-SMA protein was significantly increased only in DC cells compared to PF and CT cells, CCT-eta protein was significantly increased in both PF and DC cells compared to CT cells. siRNA-mediated depletion of CCT-eta inhibited the accumulation of both CCT-eta and α-SMA protein in DC cells, and also significantly decreased the contractility of treated DC cells. These observations suggest that increased expression of CCT-eta appears to be a marker for latent and active disease in these patients and to be essential for the increased contractility exhibited by these fibroblasts. PMID:23292503

  8. Stacking multiple transgenes at a selected genomic site via repeated recombinase-mediated DNA cassette exchanges.

    PubMed

    Li, Zhongsen; Moon, Bryan P; Xing, Aiqiu; Liu, Zhan-Bin; McCardell, Richard P; Damude, Howard G; Falco, S Carl

    2010-10-01

    Recombinase-mediated DNA cassette exchange (RMCE) has been successfully used to insert transgenes at previously characterized genomic sites in plants. Following the same strategy, groups of transgenes can be stacked to the same site through multiple rounds of RMCE. A gene-silencing cassette, designed to simultaneously silence soybean (Glycine max) genes fatty acid ω-6 desaturase 2 (FAD2) and acyl-acyl carrier protein thioesterase 2 (FATB) to improve oleic acid content, was first inserted by RMCE at a precharacterized genomic site in soybean. Selected transgenic events were subsequently retransformed with the second DNA construct containing a Yarrowia lipolytica diacylglycerol acyltransferase gene (DGAT1) to increase oil content by the enhancement of triacylglycerol biosynthesis and three other genes, a Corynebacterium glutamicum dihydrodipicolinate synthetase gene (DHPS), a barley (Hordeum vulgare) high-lysine protein gene (BHL8), and a truncated soybean cysteine synthase gene (CGS), to improve the contents of the essential amino acids lysine and methionine. Molecular characterization confirmed that the second RMCE successfully stacked the four overexpression cassettes to the previously integrated FAD2-FATB gene-silencing cassette. Phenotypic analyses indicated that all the transgenes expressed expected phenotypes. PMID:20720171

  9. The Non-canonical Tetratricopeptide Repeat (TPR) Domain of Fluorescent (FLU) Mediates Complex Formation with Glutamyl-tRNA Reductase*

    PubMed Central

    Zhang, Min; Zhang, Feilong; Fang, Ying; Chen, Xuemin; Chen, Yuhong; Zhang, Wenxia; Dai, Huai-En; Lin, Rongcheng; Liu, Lin

    2015-01-01

    The tetratricopeptide repeat (TPR)-containing protein FLU is a negative regulator of chlorophyll biosynthesis in plants. It directly interacts through its TPR domain with glutamyl-tRNA reductase (GluTR), the rate-limiting enzyme in the formation of δ-aminolevulinic acid (ALA). Delineation of how FLU binds to GluTR is important for understanding the molecular basis for FLU-mediated repression of synthesis of ALA, the universal tetrapyrrole precursor. Here, we characterize the FLU-GluTR interaction by solving the crystal structures of the uncomplexed TPR domain of FLU (FLUTPR) at 1.45-Å resolution and the complex of the dimeric domain of GluTR bound to FLUTPR at 2.4-Å resolution. Three non-canonical TPR motifs of each FLUTPR form a concave surface and clamp the helix bundle in the C-terminal dimeric domain of GluTR. We demonstrate that a 2:2 FLUTPR-GluTR complex is the functional unit for FLU-mediated GluTR regulation and suggest that the formation of the FLU-GluTR complex prevents glutamyl-tRNA, the GluTR substrate, from binding with this enzyme. These results also provide insights into the spatial regulation of ALA synthesis by the membrane-located FLU protein. PMID:26037924

  10. Astronaut Wendy Lawrence participates in training session in the CCT

    NASA Technical Reports Server (NTRS)

    1994-01-01

    Seated in the pilot's seat of a JSC Shuttle trainer, astronaut Wendy B. Lawrence, STS-67 flight engineer, participates in a training session. The 1992 astronaut class graduate is in the crew compartment trainer (CCT) of JSC's Shuttle mockup and integration laboratory.

  11. Astronaut Scott Parazynski in hatch of CCT during training

    NASA Technical Reports Server (NTRS)

    1994-01-01

    Astronaut Scott E. Parazynski, STS-66 mission specialist, poses near the hatchway of the crew compartment trainer (CCT) (out of frame) in JSC's Shuttle mockup and integration laboratory. Crew members were about to begin a rehearsal of procedures to be followed during the launch and entry phases of their flight. That rehearsal was followed by a training session on emergency egress procedures.

  12. Astronaut Scott Parazynski in hatch of CCT during training

    NASA Technical Reports Server (NTRS)

    1994-01-01

    Astronaut Scott E. Parazynski, STS-66 mission specialist, poses at the hatch of the crew compartment trainer (CCT) prior to a rehearsal of launch and entry procedures for a November 1994 flight aboard the Space Shuttle Atlantis. Parazynski is wearing his launch and entry suit for this training session.

  13. Astronaut Tamara Jernigan in the CCT during a training session

    NASA Technical Reports Server (NTRS)

    1994-01-01

    Astronaut Tamara E. Jernigan, STS-67 payload commander, is shown here in the Shuttle Training Facility at JSC participating in a training session. Jernigan is training with the RMS controls in the Crew Compartment Trainer (CCT) of JSC's Shuttle mockup and integration laboratory.

  14. CDA Leadership Program Final Report: Emerging Themes. CCT Reports

    ERIC Educational Resources Information Center

    Baker, Terry L.; Gilmour, Kara

    2004-01-01

    The Education Development Center's Center for Children and Technology (EDC/CCT) conducted an assessment of the Center of Arts Education's (CAE) Curriculum Development and Access (CDA) Leadership grant program implemented in 18 of the original recipient sites of the Annenberg Partnership program. The overall goals of the research were to assess the…

  15. Contribution of the Type II Chaperonin, TRiC/CCT, to Oncogenesis

    PubMed Central

    Roh, Soung-Hun; Kasembeli, Moses; Bakthavatsalam, Deenadayalan; Chiu, Wah; Tweardy, David J.

    2015-01-01

    The folding of newly synthesized proteins and the maintenance of pre-existing proteins are essential in sustaining a living cell. A network of molecular chaperones tightly guides the folding, intracellular localization, and proteolytic turnover of proteins. Many of the key regulators of cell growth and differentiation have been identified as clients of molecular chaperones, which implies that chaperones are potential mediators of oncogenesis. In this review, we briefly provide an overview of the role of chaperones, including HSP70 and HSP90, in cancer. We further summarize and highlight the emerging the role of chaperonin TRiC (T-complex protein-1 ring complex, also known as CCT) in the development and progression of cancer mediated through its critical interactions with oncogenic clients that modulate growth deregulation, apoptosis, and genome instability in cancer cells. Elucidation of how TRiC modulates the folding and function of oncogenic clients will provide strategies for developing novel cancer therapies. PMID:26561808

  16. Identification of an Alu-repeat-mediated deletion of OPTN upstream region in a patient with a complex ocular phenotype.

    PubMed

    Schilter, Kala F; Reis, Linda M; Sorokina, Elena A; Semina, Elena V

    2015-11-01

    Genetic causes of ocular conditions remain largely unknown. To reveal the molecular basis for a congenital ocular phenotype associated with glaucoma we performed whole-exome sequencing (WES) and whole-genome copy number analyses of patient DNA. WES did not identify a causative variant. Copy number variation analysis identified a deletion of 10p13 in the patient and his unaffected father; the deletion breakpoint contained a single 37-bp sequence that is normally present in two distinct Alu repeats separated by ~181 kb. The deletion removed part of the upstream region of optineurin (OPTN) as well as the upstream sequence and two coding exons of coiled-coil domain containing 3 (CCDC3); analysis of the patient's second allele showed normal OPTN and CCDC3 sequences. Studies of zebrafish orthologs identified expression in the developing eye for both genes. OPTN is a known factor in dominant adult-onset glaucoma and Amyotrophic Lateral Sclerosis (ALS). The deletion eliminates 98 kb of the OPTN upstream sequence leaving only ~1 kb of the proximal promoter region. Comparison of transcriptional activation capability of the 3 kb normal and the rearranged del(10)(p13) OPTN promoter sequences demonstrated a statistically significant decrease for the deleted allele; sequence analysis of the entire deleted region identified multiple conserved elements with possible cis-regulatory activity. Additional screening of CCDC3 indicated that heterozygous loss-of-function alleles are unlikely to cause congenital ocular disease. In summary, we report the first regulatory region deletion involving OPTN, caused by Alu-mediated nonallelic homologous recombination and possibly contributing to the patient's ocular phenotype. In addition, our data indicate that Alu-mediated rearrangements of the OPTN upstream region may represent a new source of affected alleles in human conditions. Evaluation of the upstream OPTN sequences in additional ocular and ALS patients may help to determine the role

  17. Modulation of HIV transcription by CD8+ cells is mediated via multiple elements of the long terminal repeat

    PubMed Central

    Maslove, D M; Ni, L W; Hawley-Foss, N C; Badley, A D; Copeland, K F T

    2001-01-01

    HIV replication and LTR-mediated gene expression can be modulated by CD8+ cells in a cell type-dependent manner. We have previously shown that supernatant fluids of activated CD8+ cells of HIV-infected individuals suppress long terminal repeat (LTR)-mediated transcription of HIV in T cells while enhancing transcription in monocytic cells. Here, we have examined the effect of culture of T cells and monocytic cells with CD8+ supernatant fluids, and subsequent binding of transcription factors to the HIV-1 LTR. In transfections using constructs in which NFκB or NFAT-1 sites were mutated, the LTR retained the ability to respond positively to culture with CD8 supernatant fluid in monocytic cells. Nuclear extracts prepared from both Jurkat T cells and U38 monocytic cells cultured with CD8+ cell supernatant fluid demonstrated increased binding to the HIV-1 LTR at an AP-1 site which overlapped the chicken ovalbumin upstream promoter (COUP) site. In monocytic cells, increased binding activity was observed at the NFκB sites of the LTR. In contrast, an inhibition in binding at the NFκB sites was observed in Jurkat cells. Examination of two NFAT-1 sites revealed enhanced binding at −260 to −275 bp in U38 cells which was reduced by cellular activation. PMA and ionomycin-induced binding at a second NFAT-1 site (− 205 to −216 bp) was abrogated by CD8+ cell supernatant fluid in T cells. These results, taken together, suggest that factors present in CD8+ supernatant fluids may act through several sites of the LTR to modulate transcription in a cell type-dependant manner. PMID:11472432

  18. Modulation of STAT3 Folding and Function by TRiC/CCT Chaperonin

    PubMed Central

    Kasembeli, Moses; Lau, Wilson Chun Yu; Roh, Soung-Hun; Eckols, T. Kris; Frydman, Judith; Chiu, Wah; Tweardy, David J.

    2014-01-01

    Signal transducer and activator of transcription 3 (Stat3) transduces signals of many peptide hormones from the cell surface to the nucleus and functions as an oncoprotein in many types of cancers, yet little is known about how it achieves its native folded state within the cell. Here we show that Stat3 is a novel substrate of the ring-shaped hetero-oligomeric eukaryotic chaperonin, TRiC/CCT, which contributes to its biosynthesis and activity in vitro and in vivo. TRiC binding to Stat3 was mediated, at least in part, by TRiC subunit CCT3. Stat3 binding to TRiC mapped predominantly to the β-strand rich, DNA-binding domain of Stat3. Notably, enhancing Stat3 binding to TRiC by engineering an additional TRiC-binding domain from the von Hippel-Lindau protein (vTBD), at the N-terminus of Stat3, further increased its affinity for TRiC as well as its function, as determined by Stat3's ability to bind to its phosphotyrosyl-peptide ligand, an interaction critical for Stat3 activation. Thus, Stat3 levels and function are regulated by TRiC and can be modulated by manipulating its interaction with TRiC. PMID:24756126

  19. CCT-tunable LED device with excellent ACU by using micro-structure array film.

    PubMed

    Chen, Qiu; Li, Zongtao; Chen, Kaihang; Tang, Yong; Ding, Xinrui; Yu, Binhai

    2016-07-25

    We apply a microstructure array (MSA) film to improve the angular color uniformity (ACU) of a correlated-color-temperature-tunable LED (CCT-tunable LED) with tunable CCT ranging from 2700 to 6500 K. The effects of the MSA film area and the height between the film and LED are investigated and optimized. The resulting ACU is greatly improved for all CCT ranges with little luminous flux loss. For a typical CCT range of 3000-4000 K, with a full-covering MSA film and height H = 5 mm, the CCT deviation is significantly reduced from 1090 K to 218 K, with only 1.8% luminous flux loss. PMID:27464123

  20. Summary of panel session 3 -- Environmental issues affecting CCT deployment

    SciTech Connect

    Hausker, K.

    1997-12-31

    The panelists discussed a variety of environmental issues that affect CCT deployment, and more broadly speaking, power development in general. The issues were both international and domestic in nature. The author summarizes the issues discussed. A summary is also presented which highlights ideas from the panelists that could be characterized as solutions to the demand for improved environmental performance and the surrounding uncertainties. The author offers some personal comments and observations.

  1. Astronaut Thuot during extravehicular activity (EVA) training in CCT

    NASA Technical Reports Server (NTRS)

    1993-01-01

    In Space Vehicle Mockup Facility, astronaut Pierre J. Thuot retrieves gear to rehearse a suit donning exercise on the middeck. Thuot's realistic environs are provided by the shuttle crew compartment trainer (CCT). Thuot, mission specialist, and four other NASA astronauts will spend two weeks in space aboard the Space Shuttle Columbia in March of 1994. He and astronaut Andrew M. Allen have been rehearsing contingency space walks. There is no scheduled extravehicular activity (EVA) for the STS-62 flight.

  2. Expression of CCT6A mRNA in chicken granulosa cells is regulated by progesterone.

    PubMed

    Wei, Qingqing; Zhu, Guiyu; Cui, Xinxing; Kang, Li; Cao, Dingguo; Jiang, Yunliang

    2013-08-01

    CCT6A, the zeta subunit of the chaperonin containing TCP1 complex, is the only cytosolic chaperonin in eukaryotes and is estimated to assist in the folding of multiple proteins including actin, tubulin, cyclin E, myosin, transducin and the Von Hippel Lindau tumor suppressor. In this study, we examined the expression of CCT6A and progesterone receptor (PGR) mRNA in various tissues of chickens and the regulation of CCT6A and PGR mRNA in ovarian granulosa cells. Northern blot analysis revealed that CCT6A had one transcript and was highly expressed in the ovary tissues from chickens at both the sexually immature and mature stages. CCT6A mRNA expression was increased maximally from pre-hierarchy follicles to F5 follicles and subsequently declined in pre-ovulatory and post-ovulatory follicles. The expression of PGR mRNA exhibited the similar pattern to CCT6A. In granulosa cells isolated from pre-ovulatory follicles, follicle-stimulating hormone (FSH) inhibited the expression of CCT6A mRNA, whereas progesterone activated CCT6A and suppressed PGR expression in a time-dependent manner. We further investigated the regulation of CCT6A transcription by progesterone by constructing various progressive deletions and mutants and identified the core promoter element of CCT6A and the binding region of progesterone, which is located from -2056 to -2051. Taken together, our results indicate that CCT6A likely plays an important role in follicle growth, and in granulosa cells, progesterone activates CCT6A transcription via a progesterone response element (PRE) located in the distal promoter of CCT6A. PMID:23644154

  3. Activation of NMDA receptors in the brainstem, RVM and NGC, mediates mechanical hyperalgesia produced by repeated intramuscular injections of acidic saline in rats

    PubMed Central

    Da Silva, LFS; DeSantana, JM; Sluka, KA

    2010-01-01

    Repeated injections of acidic saline into the gastrocnemius muscle induced both muscle and cutaneous hypersensitivity. We have previously shown that microinjection of local anesthetic into either the rostral ventromedial medulla (RVM) or the nucleus reticularis gigantocellularis (NGC) reverses this muscle and cutaneous hypersensitivity. Although prior studies show that NMDA receptors in the RVM play a clear role in mediating visceral and inflammatory hypersensitivity, the role of NMDA receptors in the NGC, or in non-inflammatory muscle pain is unclear. Therefore, the present study evaluated involvement of the NMDA receptors in the RVM and NGC in muscle and cutaneous hypersensitivity induced by repeated intramuscular injections of acidic saline. Repeated intramuscular injections of acidic saline, 5 days apart, resulted in a bilateral decrease in the withdrawal thresholds of the paw and muscle in all groups 24 h after the second injection. Microinjection of NMDA receptor antagonists into the RVM reversed both the muscle and cutaneous hypersensitivity. However, microinjection of NMDA receptor antagonists into the NGC only reversed cutaneous, but not muscle hypersensitivity. These results suggest that NMDA receptors in the RVM mediate both muscle and cutaneous hypersensitivity, but those in the NGC mediated only cutaneous hypersensitivity after muscle insult. PMID:19853525

  4. Completing the CCT mission: The challenge of change

    SciTech Connect

    Monk, J.R.

    1997-12-31

    In order to complete the clean coal technology mission it will be necessary to determine CCT`s role in the restructured electricity industry and develop a strategy to promote that role. First, one must understand where the industry is headed and how clean coal technology fits into that future. Then, one needs to develop a strategy for getting from here to there, from where CCT is today to where it must be in five, ten or twenty years to be a viable option for decision-makers. Coal makes sense for the United States for several important reasons, not the least of which is its abundance here. It also makes sense in terms of its economic impact on large areas of the nation. And if coal makes sense, especially economically, then clean coal technology makes even more sense because of its potential to capitalize on this abundant resource in an environmentally friendly manner. But after nearly thirty years of involvement in the political world at all levels from Washington, D.C. to Washington, Indiana, the author has learned the hard way that ``common sense`` does not always, or even often, carry the day in the policymaking process. He believes that the future of clean coal technology hinges on the ability in the next few months and years to mobilize all those who favor that technology to move forward in a cohesive and coordinated effort to affect the policymaking and political process and thereby promote and accelerate CCT development. If this can be done, then the nation will be well on the way to completing the clean coal technology mission and meeting the challenge of change.

  5. STS-56 Commander Cameron and Pilot Oswald at CCT hatch during JSC training

    NASA Technical Reports Server (NTRS)

    1993-01-01

    STS-56 Discovery, Orbiter Vehicle (OV) 103, Commander Kenneth Cameron (right) and Pilot Stephen S. Oswald, wearing launch and entry suits (LESs), stand at the side hatch of the crew compartment trainer (CCT), a shuttle mockup, prior to entering the mockup. Once inside the CCT, they will don their launch and entry helmets (LEHs) and participate in emergency egress (bailout) procedures. The CCT is located in JSC's Mockup and Integration Laboratory (MAIL) Bldg 9NE.

  6. Antacids Revisited with Modern Chemical Instruments: GCMS, AAS, and CCT

    NASA Astrophysics Data System (ADS)

    Burden, Stanley L.; Petzold, Christopher J.

    1999-11-01

    Data from multiple analytical methods are often required to identify or characterize samples. Typical undergraduate experiments utilize only one or two techniques in a given experiment. This paper describes a novel experiment that requires students to obtain and interpret data from several analytical techniques to identify the brand name of a commercial antacid. Students receive a ground sample of a commercial antacid. They are required to design a set of experiments utilizing computer controlled titrations (CCT), atomic absorption (AA), gas chromatography-mass spectroscopy (GCMS), and careful quantitative manual titrations using a visual indicator of their choice to determine the brand name of their sample from a list of six to eight choices.

  7. Two Dimensional Particle Transport in the Cct Tokamak Edge Plasma

    NASA Astrophysics Data System (ADS)

    Tynan, George Robert

    The physics of particle transport in the CCT tokamak plasma edge is studied experimentally in this dissertation. A full poloidal array of Langmuir probes is used to measure the equilibrium plasma and transport properties of the CCT edge plasma during Ohmic and H-mode discharges. During Ohmic L-mode, the equilibrium plasma density and electron temperature are found to vary on a magnetic flux surface. The equilibrium plasma distribution coincides with the distribution of particle transport. Inside the last closed flux surface, convective processes dominate particle transport. Several large convective cells are observed near the limiter radius. At and beyond the limiter radius, turbulent transport is significant. The turbulence appears to be driven by the convective plasma flows. In Ohmic L-mode-like discharges, plasma transport occurs predominantly through the low-field region of the tokamak with local bad curvature. The convective cells are destroyed at the L-H transition and replaced with a more poloidally symmetric, radially narrow jet of plasma flow at the limiter radius. The jet effectively isolates the plasma core from the scrape -off layer. The turbulence associated with the convective cells is reduced across the edge region. Radial particle transport across the limiter radius is thus inhibited and the global particle confinement is increased. The available data suggest that the residual H-mode particle transport is more poloidally symmetric.

  8. Lung injury mediated by antibodies to endothelium. II. Study of the effect of repeated antigen-antibody interactions in rabbits tolerant to heterologous antibody.

    PubMed Central

    Camussi, G.; Caldwell, P. R.; Andres, G.; Brentjens, J. R.

    1987-01-01

    The effect of repeated interactions of antibodies with cell surface antigens have been examined in in vitro, but not in in vivo systems. In this study are described the results of multiple antibody-cell surface antigen interactions in vivo. Rabbits were given repeated intravenous injections of goat antibodies to angiotensin converting enzyme (ACE), an antigen expressed on the surface of lung endothelial cells. For prevention of anaphylactic reactions, which would have been induced by multiple injections of heterologous immune or nonimmune IgG, the rabbits were made neonatally tolerant to goat IgG. Divalent immune IgG given daily for 21 days induced chronic antigenic modulation (antigen disappearance) with resistance to antibody-mediated inflammatory lesions. The rabbits, however, developed degenerative changes of alveolar endothelial and epithelial cells. Administration of immune IgG every other day for 43 days allowed partial reexpression of ACE and was associated with intravascular, but not interstitial, inflammatory changes. In contrast, repeated administration of monovalent immune Fab did not induce antigenic modulation but caused severe, lethal, interstitial pneumonitis. Thus, in this experimental model the development of acute interstitial inflammatory changes correlates with persistence of antigen and is abrogated by disappearance of antigen induced by divalent antibodies. Further, repeated endothelial antigen antibody interactions fail to induce chronic inflammatory or sclerosing lung lesions. Images Figure 5 Figure 6 Figure 11 Figure 12 Figure 13 Figure 1 Figure 2 Figure 3 Figure 4 Figure 7 Figure 7 Figure 9 Figure 10 PMID:3034065

  9. Membrane lipid compositional sensing by the inducible amphipathic helix of CCT.

    PubMed

    Cornell, Rosemary B

    2016-08-01

    The amphipathic helical (AH) membrane binding motif is recognized as a major device for lipid compositional sensing. We explore the function and mechanism of sensing by the lipid biosynthetic enzyme, CTP:phosphocholine cytidylyltransferase (CCT). As the regulatory enzyme in phosphatidylcholine (PC) synthesis, CCT contributes to membrane PC homeostasis. CCT directly binds and inserts into the surface of bilayers that are deficient in PC and therefore enriched in lipids that enhance surface charge and/or create lipid packing voids. These two membrane physical properties induce the folding of the CCT M domain into a ≥60 residue AH. Membrane binding activates catalysis by a mechanism that has been partially deciphered. We review the evidence for CCT compositional sensing, and the membrane and protein determinants for lipid selective membrane-interactions. We consider the factors that promote the binding of CCT isoforms to the membranes of the ER, nuclear envelope, or lipid droplets, but exclude CCT from other organelles and the plasma membrane. The CCT sensing mechanism is compared with several other proteins that use an AH motif for membrane compositional sensing. This article is part of a Special Issue entitled: The cellular lipid landscape edited by Tim P. Levine and Anant K. Menon. PMID:26747646

  10. Intel Teach to the Future[R] Leadership Forum: Formative Research. CCT Reports

    ERIC Educational Resources Information Center

    Pasnik, Shelley

    2004-01-01

    Consistent with the longitudinal evaluation of the Intel Teach to the Future Essentials Course that Education Development Center's Center for Children and Technology (CCT) has been conducting since the program's inception in 2000, the Intel Foundation commissioned CCT to conduct a formative evaluation of the Leadership Forum Pilot program. This…

  11. Current Comparative Table (CCT) automates customized searches of dynamic biological databases

    PubMed Central

    Landsteiner, Benjamin R.; Olson, Michael R.; Rutherford, Robert

    2005-01-01

    The Current Comparative Table (CCT) software program enables working biologists to automate customized bioinformatics searches, typically of remote sequence or HMM (hidden Markov model) databases. CCT currently supports BLAST, hmmpfam and other programs useful for gene and ortholog identification. The software is web based, has a BioPerl core and can be used remotely via a browser or locally on Mac OS X or Linux machines. CCT is particularly useful to scientists who study large sets of molecules in today's evolving information landscape because it color-codes all result files by age and highlights even tiny changes in sequence or annotation. By empowering non-bioinformaticians to automate custom searches and examine current results in context at a glance, CCT allows a remote database submission in the evening to influence the next morning's bench experiment. A demonstration of CCT is available at and the open source software is freely available from . PMID:15980582

  12. Comparison of Critical Trajectory Methods for Direct CCT Computation for Transient Stability

    NASA Astrophysics Data System (ADS)

    Priyadi, Ardyono; Yorino, Naoto; Sasaki, Yutaka; Tanaka, Masahide; Fujiwara, Takuma; Zoka, Yoshifumi; Kakui, Hironori; Takeshita, Mitsuhiro

    This paper studies new techniques for critical trajectory method, a recent new method proposed by the authors for obtaining critical clearing time (CCT) for transient stability analysis. A specific feature of the proposed method lies in its ability to provide exact CCT without approximations since no such methods have existed so far. The method is based on the computation of the critical trajectory, which is defined as the trajectory that starts from a point on a fault-on trajectory at CCT and reaches an end point. There are a few possible methods for the treatment of the end point conditions, computational performances of the methods are investigated in terms of accuracy of CCT and computational efficiency. It is shown that the proposed methods successfully provide the exact CCT that agrees with the conventional numerical simulation method.

  13. Incorporation of shuttle CCT parameters in computer simulation models

    NASA Technical Reports Server (NTRS)

    Huntsberger, Terry

    1990-01-01

    Computer simulations of shuttle missions have become increasingly important during recent years. The complexity of mission planning for satellite launch and repair operations which usually involve EVA has led to the need for accurate visibility and access studies. The PLAID modeling package used in the Man-Systems Division at Johnson currently has the necessary capabilities for such studies. In addition, the modeling package is used for spatial location and orientation of shuttle components for film overlay studies such as the current investigation of the hydrogen leaks found in the shuttle flight. However, there are a number of differences between the simulation studies and actual mission viewing. These include image blur caused by the finite resolution of the CCT monitors in the shuttle and signal noise from the video tubes of the cameras. During the course of this investigation the shuttle CCT camera and monitor parameters are incorporated into the existing PLAID framework. These parameters are specific for certain camera/lens combinations and the SNR characteristics of these combinations are included in the noise models. The monitor resolution is incorporated using a Gaussian spread function such as that found in the screen phosphors in the shuttle monitors. Another difference between the traditional PLAID generated images and actual mission viewing lies in the lack of shadows and reflections of light from surfaces. Ray tracing of the scene explicitly includes the lighting and material characteristics of surfaces. The results of some preliminary studies using ray tracing techniques for the image generation process combined with the camera and monitor effects are also reported.

  14. A SHORT SEQUENCE IMMEDIATELY UPSTREAM OF THE INTERNAL REPEAT ELEMENTS IS CRITICAL FOR KSHV LANA MEDIATED DNA REPLICATION AND IMPACTS EPISOME PERSISTENCE

    PubMed Central

    León Vázquez, Erika De; Juillard, Franceline; Rosner, Bernard; Kaye, Kenneth M.

    2013-01-01

    Kaposi’s sarcoma-associated herpesvirus LANA (1162 residues) mediates episomal persistence of viral genomes during latency. LANA mediates viral DNA replication and segregates episomes to daughter nuclei. A 59 residue deletion immediately upstream of the internal repeat elements rendered LANA highly deficient for DNA replication and modestly deficient for the ability to segregate episomes, while smaller deletions did not. The 59 amino acid deletion reduced LANA episome persistence by ~14-fold, while sequentially smaller deletions resulted in ~3-fold, or no deficiency. Three distinct LANA regions reorganized heterochromatin, one of which contains the deleted sequence, but the deletion did not abolish LANA’s ability to alter chromatin. Therefore, this work identifies a short internal LANA sequence that is critical for DNA replication, has modest effects on episome segregation, and substantially impacts episome persistence; this region may exert its effects through an interacting host cell protein(s). PMID:24314665

  15. Are APOE ɛ genotype and TOMM40 poly-T repeat length associations with cognitive ageing mediated by brain white matter tract integrity?

    PubMed

    Lyall, D M; Harris, S E; Bastin, M E; Muñoz Maniega, S; Murray, C; Lutz, M W; Saunders, A M; Roses, A D; Valdés Hernández, M del C; Royle, N A; Starr, J M; Porteous, D J; Wardlaw, J M; Deary, I J

    2014-01-01

    Genetic polymorphisms in the APOE ɛ and TOMM40 '523' poly-T repeat gene loci have been associated with significantly increased risk of Alzheimer's disease. This study investigated the independent effects of these polymorphisms on human cognitive ageing, and the extent to which nominally significant associations with cognitive ageing were mediated by previously reported genetic associations with brain white matter tract integrity in this sample. Most participants in the Lothian Birth Cohort 1936 completed a reasoning-type intelligence test at age 11 years, and detailed cognitive/physical assessments and structural diffusion tensor brain magnetic resonance imaging at a mean age of 72.70 years (s.d.=0.74). Participants were genotyped for APOE ɛ2/ɛ3/ɛ4 status and TOMM40 523 poly-T repeat length. Data were available from 758-814 subjects for cognitive analysis, and 522-543 for mediation analysis with brain imaging data. APOE genotype was significantly associated with performance on several different tests of cognitive ability, including general factors of intelligence, information processing speed and memory (raw P-values all<0.05), independently of childhood IQ and vascular disease history. Formal tests of mediation showed that several significant APOE-cognitive ageing associations--particularly those related to tests of information processing speed--were partially mediated by white matter tract integrity. TOMM40 523 genotype was not associated with cognitive ageing. A range of brain phenotypes are likely to form the anatomical basis for significant associations between APOE genotype and cognitive ageing, including white matter tract microstructural integrity. PMID:25247594

  16. The use of CpG-free plasmids to mediate persistent gene expression following repeated aerosol delivery of pDNA/PEI complexes.

    PubMed

    Davies, Lee A; Hyde, Stephen C; Nunez-Alonso, Graciela; Bazzani, Reto P; Harding-Smith, Rebekka; Pringle, Ian A; Lawton, Anna E; Abdullah, Syahril; Roberts, Thomas C; McCormick, Dominique; Sumner-Jones, Stephanie G; Gill, Deborah R

    2012-08-01

    Aerosol gene therapy offers great potential for treating acquired and inherited lung diseases. For treatment of chronic lung diseases such as cystic fibrosis, asthma and emphysema, non-viral gene therapy will likely require repeated administration to maintain transgene expression in slowly dividing, or terminally differentiated, lung epithelial cells. When complexed with plasmid DNA (pDNA), the synthetic polymer, 25 kDa branched Polyethylenimine (PEI), can be formulated for aerosol delivery to the lungs. We show that pDNA/PEI aerosol formulations can be repeatedly administered to airways of mice on at least 10 occasions with no detectable toxicity. Interestingly, peak reporter gene activity upon repeated delivery was significantly reduced by up to 75% compared with a single administration, despite similar pDNA lung deposition at each subsequent aerosol exposure. Although the precise mechanism of inhibition is unknown, it is independent of mouse strain, does not involve an immune response, and is mediated by PEI. Importantly, using a dosing interval of 56 days, delivery of a fourth-generation, CpG-free plasmid generated high-level, sustained transgene expression, which was further boosted at subsequent administrations. Together these data indicate that pDNA/PEI aerosol formulations offer a versatile platform for gene delivery to the lung resulting in sustained transgene expression suitable for treatment of chronic lung diseases. PMID:22575838

  17. Repeatability and Reproducibility of Measurements Using a NT-530P Noncontact Tono/Pachymeter and Correlation of Central Corneal Thickness with Intraocular Pressure

    PubMed Central

    Kamiya, Kazutaka; Fujiwara, Kazuko; Shimizu, Kimiya

    2013-01-01

    Purpose. To investigate the repeatability and reproducibility of intraocular pressure (IOP) and central corneal thickness (CCT) measurements using a noncontact tono/pachymeter (NT-530P) and to assess the correlation of CCT with IOP. Methods. Forty-six eyes of healthy volunteers were measured by two examiners. Three consecutive measurements per eye were performed. Repeatability was assessed using the coefficient of variation, and reproducibility was assessed using Bland-Altman plots. Linear correlations were used to determine agreement between CCT and noncorrected IOP and CCT and corrected IOP, which was calculated using a formula built into the NT-530P. Results. The coefficient of variation for IOP was 6.4% and for CCT was 0.4%. The 95% limits of agreement between examiners were −0.17 ± 1.42 mmHg (range: −2.95 to 2.61 mmHg) for IOP, −0.93 ± 4.37 μm (range: −9.50 to 7.64 μm) for CCT. The corrected IOP was significantly higher than the noncorrected IOP (P = 0.010.3). The noncorrected IOP significantly correlated with CCT (r = −0.4883, P = 0.0006). The corrected IOP showed no significant correlation with CCT (r = −0.0285, P = 0.8509). Conclusions. NT-530P offered repeatability and reproducibility in both IOP and CCT measurements. The corrected IOP calculated using the NT-530P was independent of the CCT, suggesting that this IOP may be less influenced by the central corneal thickness. PMID:24222904

  18. Peculiarities of piRNA-mediated post-transcriptional silencing of Stellate repeats in testes of Drosophila melanogaster.

    PubMed

    Kotelnikov, Roman N; Klenov, Mikhail S; Rozovsky, Yakov M; Olenina, Ludmila V; Kibanov, Mikhail V; Gvozdev, Vladimir A

    2009-06-01

    Silencing of Stellate genes in Drosophila melanogaster testes is caused by antisense piRNAs produced as a result of transcription of homologous Suppressor of Stellate (Su(Ste)) repeats. Mechanism of piRNA-dependent Stellate repression remains poorly understood. Here, we show that deletion of Su(Ste) suppressors causes accumulation of spliced, but not nonspliced Stellate transcripts both in the nucleus and cytoplasm, revealing post-transcriptional degradation of Stellate RNA as the predominant mechanism of silencing. We found a significant amount of Su(Ste) piRNAs and piRNA-interacting protein Aubergine (Aub) in the nuclear fraction. Immunostaining of isolated nuclei revealed co-localization of a portion of cellular Aub with the nuclear lamina. We suggest that the piRNA-Aub complex is potentially able to perform Stellate silencing in the cell nucleus. Also, we revealed that the level of the Stellate protein in Su(Ste)-deficient testes is increased much more dramatically than the Stellate mRNA level. Similarly, Su(Ste) repeats deletion exerts an insignificant effect on mRNA abundance of the Ste-lacZ reporter, but causes a drastic increase of beta-gal activity. In cell culture, exogenous Su(Ste) dsRNA dramatically decreases beta-gal activity of hsp70-Ste-lacZ construct, but not its mRNA level. We suggest that piRNAs, similarly to siRNAs, degrade only unmasked transcripts, which are accessible for translation. PMID:19321499

  19. Peculiarities of piRNA-mediated post-transcriptional silencing of Stellate repeats in testes of Drosophila melanogaster

    PubMed Central

    Kotelnikov, Roman N.; Klenov, Mikhail S.; Rozovsky, Yakov M.; Olenina, Ludmila V.; Kibanov, Mikhail V.; Gvozdev, Vladimir A.

    2009-01-01

    Silencing of Stellate genes in Drosophila melanogaster testes is caused by antisense piRNAs produced as a result of transcription of homologous Suppressor of Stellate (Su(Ste)) repeats. Mechanism of piRNA-dependent Stellate repression remains poorly understood. Here, we show that deletion of Su(Ste) suppressors causes accumulation of spliced, but not nonspliced Stellate transcripts both in the nucleus and cytoplasm, revealing post-transcriptional degradation of Stellate RNA as the predominant mechanism of silencing. We found a significant amount of Su(Ste) piRNAs and piRNA-interacting protein Aubergine (Aub) in the nuclear fraction. Immunostaining of isolated nuclei revealed co-localization of a portion of cellular Aub with the nuclear lamina. We suggest that the piRNA–Aub complex is potentially able to perform Stellate silencing in the cell nucleus. Also, we revealed that the level of the Stellate protein in Su(Ste)-deficient testes is increased much more dramatically than the Stellate mRNA level. Similarly, Su(Ste) repeats deletion exerts an insignificant effect on mRNA abundance of the Ste-lacZ reporter, but causes a drastic increase of β-gal activity. In cell culture, exogenous Su(Ste) dsRNA dramatically decreases β-gal activity of hsp70-Ste-lacZ construct, but not its mRNA level. We suggest that piRNAs, similarly to siRNAs, degrade only unmasked transcripts, which are accessible for translation. PMID:19321499

  20. STS-26 crew trains in JSC crew compartment trainer (CCT) shuttle mockup

    NASA Technical Reports Server (NTRS)

    1988-01-01

    STS-26 Discovery, Orbiter Vehicle (OV) 103, Commander Frederick H. Hauck tests cushion outside the crew compartment trainer (CCT) side hatch. Hauck, wearing new (navy blue) partial pressure suit (launch and entry suit (LES)) and helmet, tumbles out CCT side hatch onto cushion as technicians look on. During Crew Station Review (CSR) #3, the crew donned the new partial pressure suits and checked out crew escape system (CES) configurations to evaluate crew equipment and procedures related to emergency egress methods and proposed crew escape options. CCT is located in JSC's Shuttle Mockup and Integration Laboratory Bldg 9A.

  1. STS-31 Crew Training: Inflight Maintenance and Bailout Exercises in CCT and WETF

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The crew is shown in the CCT practicing on orbit maintenance tasks, along with bailout procedures. The crew is also shown practicing water survival techniques in the Weightless Environment Training Facility (WETF).

  2. Astronauts Allen and Gemar during extravehicular activity (EVA) training in CCT

    NASA Technical Reports Server (NTRS)

    1994-01-01

    Astronauts Charles D. (Sam) Gemar, and Andrew M. Allen participate in a training exercise at JSC's Crew Compartment Trainer (CCT), located in the Space Vehicle Mockup Facility. Gemar sits inside the airlock as Allen reviews procedures for EVA.

  3. STS-57 MS4 Voss, in LES, sits on CCT middeck during JSC egress training

    NASA Technical Reports Server (NTRS)

    1993-01-01

    STS-57 Endeavour, Orbiter Vehicle (OV) 105, Mission Specialist 4 (MS4) Janice E. Voss, wearing launch and entry suit (LES) and launch and entry helmet (LEH), listens to communications as she sits on the middeck of JSC's Crew Compartment Trainer (CCT), a space shuttle mockup. Voss, along with the other STS-57 crewmembers, is participating in side hatch emergency egress training. In the background, training instructors look on. The CCT is located in JSC's Mockup and Integration Laboratory (MAIL) Bldg 9NE.

  4. STS-54 MS1 Runco participates in camera familiarization in JSC's CCT

    NASA Technical Reports Server (NTRS)

    1992-01-01

    STS-54 Endeavour, Orbiter Vehicle (OV) 105, Mission Specialist 1 (MS1) Mario Runco, Jr holds a CANNON video camcorder on the middeck of JSC's Crew Compartment Trainer (CCT) during a camera familiarization session. Runco is seated on a stowed mission specialist seat in front of the forward middeck lockers as he contemplates how to best capture the subject (activity). The CCT is located in JSC's Mockup and Integration Laboratory (MAIL) Bldg 9NE.

  5. STS-45 Payload Specialists on JSC's CCT middeck during egress training

    NASA Technical Reports Server (NTRS)

    1991-01-01

    STS-45 Atlantis, Orbiter Vehicle (OV) 104, Payload Specialist Dirk D. Frimout (foreground) adjusts his launch and entry helmet (LEH) as Payload Specialist Byron K. Lichtenberg looks on. The crewmembers, wearing launch and entry suits (LESs) and LEHs, are seated on the middeck of the crew compartment trainer (CCT) during side hatch emergency egress training. The CCT is located in JSC's Mockup and Integration Laboratory (MAIL) Bldg 9A.

  6. STS-26 crew stowage review in Bldg 9A crew compartment trainer (CCT)

    NASA Technical Reports Server (NTRS)

    1988-01-01

    STS-26 Discovery, Orbiter Vehicle (OV) 103, crewmembers rehearse for their upcoming mission in the crew compartment trainer (CCT) located in the JSC Mockup and Integration Laboratory Bldg 9A. Standing on the CCT middeck, the crewmembers have just selected a snack from the meal tray assembly (foodtray) mounted on the forward middeck lockers. Left to right are Mission Specialist (MS) John M. Lounge, Commander Frederick H. Hauck, and MS George D. Nelson.

  7. STS-26 crew stowage review in Bldg 9A crew compartment trainer (CCT)

    NASA Technical Reports Server (NTRS)

    1988-01-01

    STS-26 Discovery, Orbiter Vehicle (OV) 103, crewmembers rehearse for their upcoming mission in the crew compartment trainer (CCT) located in the JSC Mockup and Integration Laboratory Bldg 9A. Standing on the CCT middeck, Pilot Richard O. Covey hands a snack package to Mission Specialist (MS) John M. Lounge (back to the camera). Covey selected the snack from the meal tray assemblies (foodtrays) mounted on the forward middeck lockers.

  8. Antiparallel protocadherin homodimers use distinct affinity- and specificity-mediating regions in cadherin repeats 1-4

    PubMed Central

    Nicoludis, John M; Vogt, Bennett E; Green, Anna G; Schärfe, Charlotta PI; Marks, Debora S; Gaudet, Rachelle

    2016-01-01

    Protocadherins (Pcdhs) are cell adhesion and signaling proteins used by neurons to develop and maintain neuronal networks, relying on trans homophilic interactions between their extracellular cadherin (EC) repeat domains. We present the structure of the antiparallel EC1-4 homodimer of human PcdhγB3, a member of the γ subfamily of clustered Pcdhs. Structure and sequence comparisons of α, β, and γ clustered Pcdh isoforms illustrate that subfamilies encode specificity in distinct ways through diversification of loop region structure and composition in EC2 and EC3, which contains isoform-specific conservation of primarily polar residues. In contrast, the EC1/EC4 interface comprises hydrophobic interactions that provide non-selective dimerization affinity. Using sequence coevolution analysis, we found evidence for a similar antiparallel EC1-4 interaction in non-clustered Pcdh families. We thus deduce that the EC1-4 antiparallel homodimer is a general interaction strategy that evolved before the divergence of these distinct protocadherin families. DOI: http://dx.doi.org/10.7554/eLife.18449.001 PMID:27472898

  9. Antiparallel protocadherin homodimers use distinct affinity- and specificity-mediating regions in cadherin repeats 1-4.

    PubMed

    Nicoludis, John M; Vogt, Bennett E; Green, Anna G; Schärfe, Charlotta Pi; Marks, Debora S; Gaudet, Rachelle

    2016-01-01

    Protocadherins (Pcdhs) are cell adhesion and signaling proteins used by neurons to develop and maintain neuronal networks, relying on trans homophilic interactions between their extracellular cadherin (EC) repeat domains. We present the structure of the antiparallel EC1-4 homodimer of human PcdhγB3, a member of the γ subfamily of clustered Pcdhs. Structure and sequence comparisons of α, β, and γ clustered Pcdh isoforms illustrate that subfamilies encode specificity in distinct ways through diversification of loop region structure and composition in EC2 and EC3, which contains isoform-specific conservation of primarily polar residues. In contrast, the EC1/EC4 interface comprises hydrophobic interactions that provide non-selective dimerization affinity. Using sequence coevolution analysis, we found evidence for a similar antiparallel EC1-4 interaction in non-clustered Pcdh families. We thus deduce that the EC1-4 antiparallel homodimer is a general interaction strategy that evolved before the divergence of these distinct protocadherin families. PMID:27472898

  10. Current Comparative Table (CCT) automates customized searches of dynamic biological databases.

    PubMed

    Landsteiner, Benjamin R; Olson, Michael R; Rutherford, Robert

    2005-07-01

    The Current Comparative Table (CCT) software program enables working biologists to automate customized bioinformatics searches, typically of remote sequence or HMM (hidden Markov model) databases. CCT currently supports BLAST, hmmpfam and other programs useful for gene and ortholog identification. The software is web based, has a BioPerl core and can be used remotely via a browser or locally on Mac OS X or Linux machines. CCT is particularly useful to scientists who study large sets of molecules in today's evolving information landscape because it color-codes all result files by age and highlights even tiny changes in sequence or annotation. By empowering non-bioinformaticians to automate custom searches and examine current results in context at a glance, CCT allows a remote database submission in the evening to influence the next morning's bench experiment. A demonstration of CCT is available at http://orb.public.stolaf.edu/CCTdemo and the open source software is freely available from http://sourceforge.net/projects/orb-cct. PMID:15980582

  11. The combined influence of fat consumption and repeated mental stress on brachial artery flow-mediated dilatation: a preliminary study.

    PubMed

    Poitras, Veronica J; Slattery, David J; Levac, Brendan M; Fergus, Stevenson; Gurd, Brendon J; Pyke, Kyra E

    2014-04-01

    Experienced separately, both acute mental stress and high-fat meal consumption can transiently impair endothelial function, and the purpose of the present study was to investigate their combined impact. On four separate days, 10 healthy men (23 years old) underwent brachial artery flow-mediated dilatation (FMD) tests, before and hourly for 4 h post-consumption of a high-fat (HFM; 54 g fat) or low-fat meal (LFM; 0 g fat; each meal ∼ 1000 calories), with hourly mental stress (mental arithmetic, speech) or control (counting) tasks (conditions HFM+S, LFM+S, HFM and LFM). Data are presented as means ± SD. Plasma triglycerides increased and remained elevated after the high-fat but not the low-fat meal (P = 0.004) and were not affected by mental stress (P = 0.329). Indices of stress reactivity increased during mental stress tasks (mean arterial pressure, ∼ 20 mmHg; heart rate, ∼ 22 beats min(-1); salivary cortisol, ∼ 2.37 nmol l(-1); and plasma noradrenaline, ∼ 0.17 ng ml(-1)) and were not influenced by meal (P > 0.05). There was no effect of the type of meal on FMD (P = 0.562); however, FMD was 4.5 ± 0.5% in the control conditions and 5.8 ± 0.6% in the mental stress conditions (P = 0.087), and this difference was significant when normalized for the shear stress stimulus (FMD/area under the curve of shear stress, P = 0.045). Overall, these preliminary data suggest that postprandial FMD was augmented with mental stress irrespective of meal type. These results are contrary to previous reports of impaired endothelial function after mental stress or fat consumption independently and highlight the need to further investigate the mechanisms underlying the interactions between these factors. PMID:24465021

  12. Hemodynamic and affective correlates assessed during performance on the Columbia card task (CCT).

    PubMed

    Holper, Lisa; Murphy, Ryan O

    2014-12-01

    The study aimed to test the potential of functional near-infrared spectroscopy (fNIRS) in combination with electrodermal activity (EDA) in a decision paradigm by means of the Columbia card task (CCT). The CCT is a dynamic decision task characterized by assessing subjects' risk-taking via eliciting voluntary stopping points in a series of incrementally increasingly risky choices. Using the combined fNIRS-EDA approach, we aim to examine the hemodynamic and affective correlates of both decision and outcome responses during performance on the CCT. Twenty healthy subjects completed the Cold and Hot CCT version while fNIRS over prefrontal cortex and EDA were recorded. Results showed that (1) in the decision phase fNIRS revealed larger total hemoglobin concentration changes [tHb] in the Cold as compared to the Hot CCT, whereas EDA revealed an opposite pattern with larger skin conductance responses (SCRs) to the Hot as compared to the Cold CCT. (2) No significant [tHb] signals or SCRs were found in the outcome phase. (3) Coherence calculations between fNIRS and EDA in the heart rate frequency showed a significant increase during the Hot as compared to the Cold CCT. Our findings designate fNIRS as suitable tool for monitoring decision-making processes. The combination of fNIRS and EDA demonstrates the potential of simultaneously assessing the interaction between hemodynamic and affective responses which can provide additional information concerning the relationship between these two physiological systems for various research areas. PMID:24242358

  13. Ca-activated K channels in apical membrane of mammalian CCT, and their role in K secretion.

    PubMed

    Frindt, G; Palmer, L G

    1987-03-01

    High conductance, Ca-activated K channels were studied in the apical membrane of the rat cortical collecting tubule (CCT) using the patch-clamp technique. In cell-attached patches the channels were found mainly in the closed state at the spontaneous apical membrane potential. They spent progressively more time in the open state as the pipette potential was made negative relative to the bath. In excised patches these channels had a high selectivity for K over Na and were activated by micromolar concentrations of Ca2+ on the cytoplasmic side of the membrane in a voltage-dependent manner. They had a low conductance to Rb and were blocked by Ba (1-100 microM) from the cytoplasmic side and tetraethylammonium (TEA) (0.2-1 mM) from the luminal side. Block by external TEA and small conductance to Rb were used to investigate the role of these channels in K transport by the isolated perfused rabbit CCT. Ba (2.5 mM), a well-studied blocker of apical K conductance in this segment, hyperpolarized the transepithelial voltage (VT) by 3.7 +/- 0.9 mV when added to the luminal solution of the perfused tubule. Addition of TEA (5 mM) to the luminal solution has no effect on VT. When Na transport was abolished by luminal amiloride, perfusion with 30 mM K (replacing Na) resulted in a lumen-negative VT (18-34 mV). Under these conditions, VT was reduced by 6.0 +/- 1.5 mV by 2.5 mM Ba, whereas TEA had no effect. Perfusion with 30 mM Rb (replacing Na) also caused a lumen-negative VT that was approximately 50% of that observed with 30 mM K. The apical K conductance of the perfused CCT appears to be insensitive to luminal TEA and only modestly selective for K over Rb. This conductance, at least under the conditions of our studies, is probably not mediated by the high conductance Ca-activated K channel. PMID:2435175

  14. Potential for thermal coal and Clean Coal Technology (CCT) in the Asia-Pacific

    SciTech Connect

    Johnson, C.J.; Long, S.

    1991-11-22

    The Coal Project was able to make considerable progress in understanding the evolving energy situation in Asia and the future role of coal and Clean Coal Technologies. It is clear that there will be major growth in consumption of coal in Asia over the next two decades -- we estimate an increase of 1.2 billion metric tons. Second, all governments are concerned about the environmental impacts of increased coal use, however enforcement of regulations appears to be quite variable among Asian countries. There is general caution of the part of Asian utilities with respect to the introduction of CCT's. However, there appears to be potential for introduction of CCT's in a few countries by the turn of the century. It is important to emphasize that it will be a long term effort to succeed in getting CCT's introduced to Asia. The Coal Project recommends that the US CCT program be expanded to allow the early introduction of CCT's in a number of countries.

  15. Repeated PM2.5 exposure inhibits BEAS-2B cell P53 expression through ROS-Akt-DNMT3B pathway-mediated promoter hypermethylation

    PubMed Central

    Zhou, Wei; Tian, Dongdong; He, Jun; Wang, Yimei; Zhang, Lijun; Cui, Lan; jia, Li; Zhang, Li; Li, Lizhong; Shu, Yulei; Yu, Shouzhong; Zhao, Jun; Yuan, Xiaoyan; Peng, Shuangqing

    2016-01-01

    Long-term exposure to fine particulate matter (PM2.5) has been reported to be closely associated with the increased lung cancer risk in populations, but the mechanisms underlying PM-associated carcinogenesis are not yet clear. Previous studies have indicated that aberrant epigenetic alterations, such as genome-wide DNA hypomethylation and gene-specific DNA hypermethylation contribute to lung carcinogenesis. And silence or mutation of P53 tumor suppressor gene is the most prevalent oncogenic driver in lung cancer development. To explore the effects of PM2.5 on global and P53 promoter methylation changes and the mechanisms involved, we exposed human bronchial epithelial cells (BEAS-2B) to low concentrations of PM2.5 for 10 days. Our results indicated that PM2.5-induced global DNA hypomethylation was accompanied by reduced DNMT1 expression. PM2.5 also induced hypermethylation of P53 promoter and inhibited its expression by increasing DNMT3B protein level. Furthermore, ROS-induced activation of Akt was involved in PM2.5-induced increase in DNMT3B. In conclusion, our results strongly suggest that repeated exposure to PM2.5 induces epigenetic silencing of P53 through ROS-Akt-DNMT3B pathway-mediated promoter hypermethylation, which not only provides a possible explanation for PM-induced lung cancer, but also may help to identify specific interventions to prevent PM-induced lung carcinogenesis. PMID:26942697

  16. Assisted protein folding at low temperature: evolutionary adaptation of the Antarctic fish chaperonin CCT and its client proteins

    PubMed Central

    Cuellar, Jorge; Yébenes, Hugo; Parker, Sandra K.; Carranza, Gerardo; Serna, Marina; Valpuesta, José María; Zabala, Juan Carlos; Detrich, H. William

    2014-01-01

    ABSTRACT Eukaryotic ectotherms of the Southern Ocean face energetic challenges to protein folding assisted by the cytosolic chaperonin CCT. We hypothesize that CCT and its client proteins (CPs) have co-evolved molecular adaptations that facilitate CCT–CP interaction and the ATP-driven folding cycle at low temperature. To test this hypothesis, we compared the functional and structural properties of CCT–CP systems from testis tissues of an Antarctic fish, Gobionotothen gibberifrons (Lönnberg) (habitat/body T = −1.9 to +2°C), and of the cow (body T = 37°C). We examined the temperature dependence of the binding of denatured CPs (β-actin, β-tubulin) by fish and bovine CCTs, both in homologous and heterologous combinations and at temperatures between −4°C and 20°C, in a buffer conducive to binding of the denatured CP to the open conformation of CCT. In homologous combination, the percentage of G. gibberifrons CCT bound to CP declined linearly with increasing temperature, whereas the converse was true for bovine CCT. Binding of CCT to heterologous CPs was low, irrespective of temperature. When reactions were supplemented with ATP, G. gibberifrons CCT catalyzed the folding and release of actin at 2°C. The ATPase activity of apo-CCT from G. gibberifrons at 4°C was ∼2.5-fold greater than that of apo-bovine CCT, whereas equivalent activities were observed at 20°C. Based on these results, we conclude that the catalytic folding cycle of CCT from Antarctic fishes is partially compensated at their habitat temperature, probably by means of enhanced CP-binding affinity and increased flexibility of the CCT subunits. PMID:24659247

  17. STS-26 crew trains in JSC crew compartment trainer (CCT) shuttle mockup

    NASA Technical Reports Server (NTRS)

    1988-01-01

    STS-26 Discovery, Orbiter Vehicle (OV) 103, Mission Specialist (MS) George D. Nelson trains in the crew compartment trainer (CCT) located in JSC's Shuttle Mockup and Integration Laboratory Bldg 9A. Nelson, wearing new (navy blue) partial pressure suit (launch and entry suit (LES)) and helmet, is strapped into his launch and entry station on the CCT middeck. During Crew Station Review (CSR) #3, the crew donned the new partial pressure suits and checked out crew escape system (CES) configurations to evaluate crew equipment and procedures related to emergency egress methods and proposed crew escape options.

  18. STS-26 crew trains in JSC crew compartment trainer (CCT) shuttle mockup

    NASA Technical Reports Server (NTRS)

    1988-01-01

    STS-26 Discovery, Orbiter Vehicle (OV) 103, crewmembers sit on flight deck of the crew compartment trainer (CCT) shuttle mockup. Pilot Richard O. Covey (left) at pilot station controls and Mission Specialist (MS) John M. Lounge (center) and MS David C. Hilmers on aft flight deck are wearing the new (navy blue) partial pressure suits (launch and entry suits (LESs)). During Crew Station Review (CSR) #3, the crew donned the new partial pressure suits and checked out crew escape system (CES) configurations to evaluate crew equipment and procedures related to emergency egress methods and proposed crew escape options. CCT shuttle mockup is located in JSC's Shuttle Mockup and Integration Laboratory Bldg 9A.

  19. STS-26 crew trains in JSC crew compartment trainer (CCT) shuttle mockup

    NASA Technical Reports Server (NTRS)

    1988-01-01

    STS-26 Discovery, Orbiter Vehicle (OV) 103, Mission Specialist (MS) George D. Nelson trains in the crew compartment trainer (CCT) located in JSC's Shuttle Mockup and Integration Laboratory Bldg 9A. Nelson, wearing new (navy blue) partial pressure suit (launch and entry suit (LES)) and helmet, peers out the open CCT side hatch and prepares to deploy inflatable slide. Technicians observe the activity from scaffolding on either side of the hatch. During Crew Station Review (CSR) #3, the crew donned the new partial pressure suits and checked out crew escape system (CES) configurations to evaluate crew equipment and procedures related to emergency egress methods and proposed crew escape options.

  20. Weathering of clean coal technology (CCT) by-products and mine spoil mixtures

    SciTech Connect

    Fowler, R.K.; Soto, U.I.; Bigham, J.M.; Traina, S.J.

    1994-12-31

    Three CCT by-products (pH range 10.5 to 12.5) and two mine spoils (pH`s of 3.0 and 5.2) were mixed at four rates of CCT (0, 10, 20, and 40 wt. %) to simulate field application conditions. All samples were sequentially extracted with water at six sampling events over a 132 day period, The effect of by-product rate and mine spoil characteristics on leachate composition and final reaction products will be discussed.

  1. STS-27 Atlantis, OV-104, crewmembers in JSC crew compartment trainer (CCT)

    NASA Technical Reports Server (NTRS)

    1988-01-01

    STS-27 Atlantis, Orbiter Vehicle (OV) 104, crewmembers, wearing launch and entry suits (LESs), participate in exercises in the JSC crew compartment trainer (CCT). The four crewmembers are pictured in the stations they will man for the launch and entry phases of the mission. At forward controls are Pilot Guy S. Gardner (left) and Commander Robert L. Gibson. Behind them are Mission Specialist (MS) Richard M. Mullane (left) and MS Jerry L. Ross. CCT is located in JSC Mockup and Integration Laboratory Bldg 9A. Photo was taken by Bill Bowers of JSC.

  2. STS-36 Commander Creighton in LES outside CCT side hatch during JSC training

    NASA Technical Reports Server (NTRS)

    1989-01-01

    Standing on an inflated cushion outside the side hatch of the crew compartment trainer (CCT), STS-36 Commander John O. Creighton, wearing launch and entry suit (LES), smiles before climbing into the shuttle mockup. The crew escape system (CES) pole extends beyond the side hatch opening. Mission Specialist (MS) Richard M. Mullane is seen at the lower corner of the frame rolling on the safety cushion. CCT is located in JSC's Mockup and Integration Laboratory (MAIL) Bldg 9A. The crewmembers are practicing egress procedures that might be necessary in the event of an emergency aboard the shuttle.

  3. STS-29 Discovery, OV-103, crewmembers in JSC crew compartment trainer (CCT)

    NASA Technical Reports Server (NTRS)

    1989-01-01

    STS-29 Discovery, Orbiter Vehicle (OV) 103, crewmembers, wearing launch and entry suits (LESs), participate in exercises in the JSC crew compartment trainer (CCT). Four crewmembers are pictured in the stations they will man for entry phase of the mission. At forward controls are Pilot John E. Blaha (left) and Commander Michael L. Coats. Behind them are Mission Specialist (MS) James P. Bagian (left) and MS James F. Buchli. CCT is located in JSC Mockup and Integration Laboratory Bldg 9A. Photo was taken by Bill Bowers of JSC.

  4. STS-56 Commander Cameron and Pilot Oswald on CCT flight deck in JSC's MAIL

    NASA Technical Reports Server (NTRS)

    1993-01-01

    STS-56 Discovery, Orbiter Vehicle (OV) 103, Commander Kenneth Cameron, (left) and Pilot Stephen S. Oswald, wearing launch and entry suits (LESs) and launch and entry helmets (LEHs), are seated on the forward flight deck of the crew compartment trainer (CCT), a shuttle mockup. Cameron mans the commander station controls and Oswald the pilots station controls during an emergency egress (bailout) simulation. The view was taken from the aft flight deck looking forward and includes Cameron's and Oswald's profiles and the forward flight deck controls and checklists. The CCT is located in JSC's Mockup and Integration Laboratory (MAIL) Bldg 9NE.

  5. STS-34 crew poses on flight deck of JSC's crew compartment trainer (CCT)

    NASA Technical Reports Server (NTRS)

    1989-01-01

    STS-34 Atlantis, Orbiter Vehicle (OV) 104, crewmembers pose on flight deck of JSC's crew compartment trainer (CCT) for group portrait. Taking a break from training and wearing launch and entry suits (LESs) are (left to right) Pilot Michael J. McCulley, Mission Specialist (MS) Shannon W. Lucid, MS Franklin R. Chang-Diaz, MS Ellen S. Baker, and Commander Donald E. Williams. All crewmembers are in their designated stations for launch and entry except Baker who will occupy a seat on OV-104's middeck. The CCT is located in JSC's Mockup and Integration Laboratory (MAIL) Bldg 9A. The photograph was taken by Bill Bowers, a crew trainer at JSC.

  6. LANDSAT-D data format control book. Volume 6, appendix D: Thematic mapper Computer Compatible Tape (CCT-AT/PT)

    NASA Technical Reports Server (NTRS)

    Ahmed, H.

    1981-01-01

    The format of computer compatible tapes which contain LANDSAT 4 and D Prime thematic mapper data is defined. A complete specification of the CCT-AT (radiometric corrections applied and geometric matrices appended) and the CCT-PT (radiometric and geometric corrections) data formats is provided.

  7. The c-rel protooncogene product represses NF-kappa B p65-mediated transcriptional activation of the long terminal repeat of type 1 human immunodeficiency virus.

    PubMed Central

    Doerre, S; Sista, P; Sun, S C; Ballard, D W; Greene, W C

    1993-01-01

    The long terminal repeat (LTR) of the type 1 human immunodeficiency virus (HIV-1) and the 5' regulatory region of the gene encoding the interleukin 2 receptor alpha subunit (IL-2R alpha) share functional kappa B enhancer elements involved in the regulation of these inducible transcription units during T-cell activation. These kappa B enhancer elements are recognized by a structurally related family of interactive proteins that includes p50, p65, and the product of the c-rel protooncogene (c-Rel). Recent biochemical studies have shown that p65 and p50 form the prototypical NF-kappa B complex, which is rapidly translocated from the cytoplasm to the nucleus during T-cell activation. This intracellular signaling complex potently stimulates kappa B-directed transcription from either the HIV-1 LTR or the IL-2R alpha promoter via the strong transactivation domain present in p65. We now demonstrate that nuclear expression of human c-Rel, which is induced by either phorbol ester or tumor necrosis factor alpha with delayed kinetics relative to p65, markedly represses p65-mediated activation of these transcription units. These inhibitory effects of c-Rel correlate with its DNA-binding activity but not with its ability to heterodimerize with p50, suggesting that c-Rel inhibition involves competition with p50/p65 for occupancy of the kappa B enhancer element. Together, these findings suggest that one function of c-Rel is as a physiologic repressor of the HIV-1 LTR and IL-2R alpha promoters, serving to efficiently counter the strong transcriptional activating effects of p65. Images PMID:8430069

  8. Computational modeling of protein folding assistance by the eukaryotic chaperonin CCT

    NASA Astrophysics Data System (ADS)

    Jayasinghe, Manori; Stan, George

    2009-03-01

    Chaperonins are biological nanomachines that promote protein folding using energy derived from ATP hydrolysis. Structurally, chaperonins are large oligomeric complexes that form double-ring construct, enclosing a central cavity that serves as folding chamber. Our focus is on the substrate binding mechanisms of the Eukaryotic chaperonin CCT and Archaeal chaperonin Thermosome. We contrast our results with the annealing action of the bacterial chaperonin GroEL of E. coli., currently the best studied for chaperonin machinery. CCT was suggested to be more selective towards the substrate recognition where as GroEL is more promiscuous due to the hydrophobic interactions. We study the interaction of CCT with Tubulin, one of its stringent substrates. Using molecular docking and molecular dynamics simulations, we probe binding of a βtubulin peptide (205-274) to the CCTγ apical domain. We identify a versatile binding mechanism, involving mostly hydrophobic interactions with the helical region and electrostatic interactions with the helical protrusion region. This specific substrate-protein recognition mechanism is likely to be optimized for specific substrate protein-CCT subunit pairs.

  9. DAO spectroscopic classification of ASASSN-16fa = AT 2016cct in UGC 6434

    NASA Astrophysics Data System (ADS)

    Balam, D. D.; Graham, M. L.

    2016-05-01

    A spectrum of ASASSN-16fa = 2016cct (ATEL #9045) was obtained using the 1.82-m Plaskett telescope (National Research Council of Canada) covering the range 375-710 nm (resolution 0.35 nm) on UT May 13.26 that reveals the object to be a type-Ia (normal) supernova near maximum light.

  10. TRUE COLORS: LEDS AND THE RELATIONSHIP BETWEEN CCT, CRI, OPTICAL SAFETY, MATERIAL DEGRADATION, AND PHOTOBIOLOGICAL STIMULATION

    SciTech Connect

    Royer, Michael P.

    2014-08-30

    This document analyzes the optical, material, and photobiological hazards of LED light sources compared to conventional light sources. It documents that LEDs generally produce the same amount of blue light, which is the primary contributor to the risks, as other sources at the same CCT. Duv may have some effect on the amount of blue light, but CRI does not.

  11. Formative Evaluation of the Intel[R] Innovation in Education Institutes. Summary Report. CCT Reports

    ERIC Educational Resources Information Center

    Keane, Julie Thompson; Keisch, Deborah; Culp, Katie McMillan

    2004-01-01

    During the summer and fall of 2003, Education Development Center's Center for Children and Technology (CCT) undertook a formative evaluation of the Intel Innovation in Education institutes. The institutes are one- to two-and-a-half day district-level trainings intended to introduce professional development providers to the online resources and…

  12. Formative Evaluation of the Intel[R] Design and Discovery Curriculum Report. CCT Reports

    ERIC Educational Resources Information Center

    Culp, Katie McMillan; Keane, Julie Thompson; Meade, Terri; Nudell, Hannah

    2004-01-01

    Between May 2003 and January 2004, Education Development Center's Center for Children and Technology (CCT) undertook a formative evaluation of Design and Discovery, a hands-on, project-based design and engineering curriculum being disseminated as part of the Intel Innovation in Education initiatives. The Design and Discovery curriculum invites 11-…

  13. Three European payload specialists in CCT training for STS 61-A

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Three European scientists have been named as payload specialists for the Spacelab D-1 (STS 61A) mission. They are (l.-r.) Wubbo Ockels of Holland and the European Space Agency (ESA); Ernst Messerschmid and Reinhold Furrer, both of West Germany and the DFVLR. They are pictured in the crew compartment trainer (CCT) at JSC.

  14. STS-49 MS Thuot, in LES, at CCT side hatch during JSC's egress exercises

    NASA Technical Reports Server (NTRS)

    1992-01-01

    STS-49 Endeavour, Orbiter Vehicle (OV) 105, Mission Specialist (MS) Pierre J. Thuot, wearing launch and entry suit (LES), prepares to enter JSC's Crew Compartment Trainer (CCT) via the open side hatch as a technician looks on. Thuot along with the other STS-49 crewmembers is participating in a post-landing emergency egress exercise in JSC's Mockup and Integration Laboratory (MAIL) Bldg 9.

  15. Portrait of the STS 61-A crew in front of the CCT

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Portrait of the STS 61-A crew in front of the Crew Compartment Trainer (CCT). Sitting are (l.-r.) Wubbo Ockels, Henry W. Harsfield, Jr., and Bonnie J. Dunbar. Standing (l.-r.) are Guion S. Bluford, Jr., Ernst Messerschmid, Steven R. Nagel, James F. Buchli, Ulf Merbold, and Reinhard Furrer.

  16. Chaperonin containing T-complex polypeptide subunit eta (CCT-eta) is a specific regulator of fibroblast motility and contractility.

    PubMed

    Satish, Latha; Johnson, Sandra; Wang, James H-C; Post, J Christopher; Ehrlich, Garth D; Kathju, Sandeep

    2010-01-01

    Integumentary wounds in mammalian fetuses heal without scar; this scarless wound healing is intrinsic to fetal tissues and is notable for absence of the contraction seen in postnatal (adult) wounds. The precise molecular signals determining the scarless phenotype remain unclear. We have previously reported that the eta subunit of the chaperonin containing T-complex polypeptide (CCT-eta) is specifically reduced in healing fetal wounds in a rabbit model. In this study, we examine the role of CCT-eta in fibroblast motility and contractility, properties essential to wound healing and scar formation. We demonstrate that CCT-eta (but not CCT-beta) is underexpressed in fetal fibroblasts compared to adult fibroblasts. An in vitro wound healing assay demonstrated that adult fibroblasts showed increased cell migration in response to epidermal growth factor (EGF) and platelet derived growth factor (PDGF) stimulation, whereas fetal fibroblasts were unresponsive. Downregulation of CCT-eta in adult fibroblasts with short inhibitory RNA (siRNA) reduced cellular motility, both basal and growth factor-induced; in contrast, siRNA against CCT-beta had no such effect. Adult fibroblasts were more inherently contractile than fetal fibroblasts by cellular traction force microscopy; this contractility was increased by treatment with EGF and PDGF. CCT-eta siRNA inhibited the PDGF-induction of adult fibroblast contractility, whereas CCT-beta siRNA had no such effect. In each of these instances, the effect of downregulating CCT-eta was to modulate the behavior of adult fibroblasts so as to more closely approximate the characteristics of fetal fibroblasts. We next examined the effect of CCT-eta modulation on alpha-smooth muscle actin (alpha-SMA) expression, a gene product well known to play a critical role in adult wound healing. Fetal fibroblasts were found to constitutively express less alpha-SMA than adult cells. Reduction of CCT-eta with siRNA had minimal effect on cellular beta-actin but

  17. Development of a carbon dioxide pressure technique for chemical stabilization of alkaline clean coal technology (CCT) ash. Final report

    SciTech Connect

    Reddy, K.J.; Gloss, S.P.; Drever, J.I.; Tawfic, T.A.

    1995-06-01

    Clean Coal Technology (CCT) ash may contain trace elements such as arsenic (As), cadmium (Cd) and selenium (Se), some of which may become mobile and leach from a disposal facility. This study was undertaken to determine the effects of a carbon dioxide (CO{sub 2}) pressure treatment on the leachability of trace elements in CCT ash. The CO{sub 2} pressure treatment was optimized using a three by five factorial design as well as a multiple regression analysis. Low, medium and high levels of moisture, reaction time, pressure, temperature and concentration of CO{sub 2} were tested. Treated and untreated CCT ash samples were subjected to X-ray diffraction (XRD) and leachability studies. A 1:4 (solid:solution) suspension was used to monitor the pH changes after each treatment. Optimum CO{sub 2} treatment conditions rapidly precipitated calcite, and thus lowered the pH of CCT ash samples. For example, a stable pH drop from 12.47 to 7.05 for CCT-1, 12.74 to 9.34 for CCT-2 and 11.50 to 9.16 for CCT-3 was obtained. An increase in percent calcium carbonate (CaCO{sub 3}) content and percent CO{sub 2} uptake was observed in CO{sub 2} treated samples. Solubility studies suggested that Ca{sup 2+} concentration in CO{sub 2} treated CCT ash leachates appeared to be regulated by CaCO{sub 3}. Our results show that reacting moist CCT ash samples with CO{sub 2} under pressure is effective in lowering the concentrations of leachable trace elements (e.g., Cd, Pb, Cr, As and Se), which could prevent their migration from disposal environments into soils and groundwaters.

  18. STS-52 PS MacLean, backup PS Tryggvason, and PI pose on JSC's CCT flight deck

    NASA Technical Reports Server (NTRS)

    1992-01-01

    STS-52 Columbia, Orbiter Vehicle (OV) 102, Canadian Payload Specialist (PS) Steven G. MacLean (left) and backup Payload Specialist Bjarni V. Tryggvason (right) take a break from a camera training session in JSC's Crew Compartment Trainer (CCT). The two Canadian Space Agency (CSA) representatives pose on the CCT's aft flight deck with Canadian scientist David Zimick, the principal investigator (PI) for the materials experiment in low earth orbit (MELEO). MELEO is a component of the CANEX-2 experiment package, manifest to fly on the scheduled October 1992 STS-52 mission. The CCT is part of the shuttle Mockup and Integration Laboratory (MAIL) Bldg 9NE.

  19. Repeating thermocouple

    SciTech Connect

    Falk, R. A.

    1985-06-04

    Disclosed herein is a repeating use thermocouple assembly and method of making the same in which a cavity adjacent the tip of the thermocouple is filled with a thermosetting foundry sand and baked in place to provide support for the thermocouple tube without causing stresses during use which could cause breakage of the thermocouple tube.

  20. STS-26 crew trains in JSC crew compartment trainer (CCT) shuttle mockup

    NASA Technical Reports Server (NTRS)

    1988-01-01

    STS-26 Discovery, Orbiter Vehicle (OV) 103, Pilot Richard O. Covey trains in the crew compartment trainer (CCT) located in JSC's Shuttle Mockup and Integration Laboratory Bldg 9A. Covey, wearing new (navy blue) partial pressure suit (launch and entry suit (LES)) and communications carrier assembly (CCA), pulls himself up onto flight deck from the middeck through the interdeck access hatch. During Crew Station Review (CSR) #3, the crew donned the new partial pressure suits and checked out crew escape system (CES) configurations to evaluate crew equipment and procedures related to emergency egress methods and proposed crew escape options. CCT is in launch (vertical) position therefore the aft middeck bulkhead becomes the floor (note technician at the side hatch).

  1. STS-26 crew trains in JSC crew compartment trainer (CCT) shuttle mockup

    NASA Technical Reports Server (NTRS)

    1988-01-01

    STS-26 Discovery, Orbiter Vehicle (OV) 103, Mission Specialist (MS) George D. Nelson trains in the crew compartment trainer (CCT) located in JSC's Shuttle Mockup and Integration Laboratory Bldg 9A. Nelson, wearing new (navy blue) partial pressure suit (launch and entry suit (LES)) and helmet, maneuvers himself into middeck mission specialists seat as MS David C. Hilmers pulls himself up onto flight deck from the middeck through the interdeck access hatch. Side hatch is closed and stowed treadmill appears in the foreground. During Crew Station Review (CSR) #3, the crew donned the new partial pressure suits and checked out crew escape system (CES) configurations to evaluate crew equipment and procedures related to emergency egress methods and proposed crew escape options. CCT is in launch (vertical) position therefore the aft middeck bulkhead and airlock become the floor.

  2. STS-26 crew trains in JSC crew compartment trainer (CCT) shuttle mockup

    NASA Technical Reports Server (NTRS)

    1988-01-01

    STS-26 Discovery, Orbiter Vehicle (OV) 103, Mission Specialist (MS) John M. Lounge trains in the crew compartment trainer (CCT) located in JSC's Shuttle Mockup and Integration Laboratory Bldg 9A. Lounge, wearing new (navy blue) partial pressure suit (launch and entry suit (LES)) and communications carrier assembly (CCA), pulls himself up onto flight deck from the middeck through the interdeck access hatch. During Crew Station Review (CSR) #3, the crew donned the new partial pressure suits and checked out crew escape system (CES) configurations to evaluate crew equipment and procedures related to emergency egress methods and proposed crew escape options. CCT is in launch (vertical) position therefore the aft middeck bulkhead becomes the floor (note technician at the side hatch).

  3. STS-26 crew trains in JSC crew compartment trainer (CCT) shuttle mockup

    NASA Technical Reports Server (NTRS)

    1988-01-01

    STS-26 Discovery, Orbiter Vehicle (OV) 103, Mission Specialist (MS) George D. Nelson trains in the crew compartment trainer (CCT) located in JSC's Shuttle Mockup and Integration Laboratory Bldg 9A. Nelson, wearing new (navy blue) partial pressure suit (launch and entry suit (LES)) and helmet, exits CCT via slide inflated at side hatch. Technicians at the bottom of the slide prepare to help Nelson to his feet as a second set of technicians observe the activity from scaffolding on either side of the open hatch. During Crew Station Review (CSR) #3, the crew donned the new partial pressure suits and checked out crew escape system (CES) configurations to evaluate crew equipment and procedures related to emergency egress methods and proposed crew escape options.

  4. STS-26 crew trains in JSC crew compartment trainer (CCT) shuttle mockup

    NASA Technical Reports Server (NTRS)

    1988-01-01

    STS-26 Discovery, Orbiter Vehicle (OV) 103, Mission Specialist (MS) David C. Hilmers trains in the crew compartment trainer (CCT) located in JSC's Shuttle Mockup and Integration Laboratory Bldg 9A. Hilmers, wearing new (navy blue) partial pressure suit (launch and entry suit (LES)) and helmet, slides out CCT side hatch on his back via platform extension. Astronaut Steven R. Nagel, who has served as both mission specialist and pilot on two previous missions, briefs Hilmers. During Crew Station Review (CSR) #3, the crew donned the new partial pressure suits and checked out crew escape system (CES) configurations to evaluate crew equipment and procedures related to emergency egress methods and proposed crew escape options.

  5. STS-27 Atlantis, OV-104, crewmembers in JSC crew compartment trainer (CCT)

    NASA Technical Reports Server (NTRS)

    1988-01-01

    STS-27 Atlantis, Orbiter Vehicle (OV) 104, crewmembers, wearing launch and entry suits (LESs), participate in exercises in the JSC crew compartment trainer (CCT). Four crewmembers are pictured in the stations they will man for the launch and entry phases of the mission. They are joined by the fifth crewmember, 'borrowed' for a moment from the middeck. At forward controls are Pilot Guy S. Gardner (left) and Commander Robert L. Gibson. Behind them are Mission Specialist (MS) Richard M. Mullane (left) and MS Jerry L. Ross. MS William M. Shepherd stands at aft station. Shepherd will occupy Atlantis' middeck for launch and entry phase of the flight. CCT is located in JSC Mockup and Integration Laboratory Bldg 9A. Photo was taken by Bill Bowers of JSC.

  6. STS-28 Columbia, OV-102, crewmembers in JSC crew compartment trainer (CCT)

    NASA Technical Reports Server (NTRS)

    1989-01-01

    STS-28 Columbia, Orbiter Vehicle (OV) 102, crewmembers, wearing launch and entry suits (LESs), participate in exercises in the JSC crew compartment trainer (CCT). Four crewmembers are pictured in the stations they will man for the launch and entry phases of the mission. They are joined by the fifth crewmember, 'borrowed' for a moment from the middeck. At forward controls are Pilot Richard N. Richards (left) and Commander Brewster H. Shaw, Jr. Behind them are Mission Specialist (MS) James C. Adamson (left) and MS David C. Leestma. MS Mark N. Brown stands at aft station. Brown will occupy Columbia's middeck for launch and entry phase of the flight. CCT is located in JSC Mockup and Integration Laboratory Bldg 9A. Photo was taken by Bill Bowers of JSC.

  7. Study of CCT varying by volume scattering diffuser with moving and rotating white light LED

    NASA Astrophysics Data System (ADS)

    Ma, Shih-Hsin; Chen, Liang-Shiun; Huang, Wen-Chao

    2014-09-01

    In this study, the corrected color temperature (CCT) of white light, which originates from a white light LED (WLLED) and passes through a volume-scattering diffuser (VSD), is investigated. The VSD with thickness of 2mm is fabricated by mixing the 2um-sized PMMA scattering particles and the epoxy glue with different concentration values. Moreover, in order to understand the influences of the illuminated area and the scattering path of VSD on CCT values, the bulletheaded and lambertian-type WLLEDs are assembled for different positions and distinct orientations along the optical axis in a black cavity. A detailed comparison between results regarding the white light with and without passing through the VSD is offered. The results of this research will help to improve the colorful consistency of the LED lamps which use diffusers.

  8. STS-29 Discovery, OV-103, crewmembers in JSC crew compartment trainer (CCT)

    NASA Technical Reports Server (NTRS)

    1989-01-01

    STS-29 Discovery, Orbiter Vehicle (OV) 103, crewmembers, wearing launch and entry suits (LESs), participate in exercises in the JSC crew compartment trainer (CCT). Four crewmembers are pictured in the stations they will man for entry phase of the mission. They are joined by the fifth crewmember, 'borrowed' for a moment from the middeck. At forward controls are Pilot John E. Blaha (left) and Commander Michael L. Coats. Behind them are Mission Specialist (MS) James P. Bagian (left) and MS James F. Buchli. MS Robert C. Springer stands at aft station. Springer will occupy Discovery's middeck for entry phase of the flight while Bagian will occupy that post for launch. CCT is located in JSC Mockup and Integration Laboratory Bldg 9A. Photo was taken by Bill Bowers of JSC.

  9. STS-54 Commander Casper at airlock hatch on CCT middeck during JSC training

    NASA Technical Reports Server (NTRS)

    1992-01-01

    STS-54 Endeavour, Orbiter Vehicle (OV) 105, Commander John H. Casper manipulates the airlock hatch and its equalization valves on the middeck of JSC's Crew Compartment Trainer (CCT). Casper is rehearsing the sequence of events necessary for extravehicular activity (EVA) egress for the upcoming STS-54 mission. Visible in the airlock is an extravehicular mobility unit (EMU). Two of the STS-54 crewmembers will don EMUs and egress through the EV hatch into the payload bay (PLB) after Casper closes the intravehicular (IV) hatch behind them. The EVA crewmembers will spend four-plus hours on a planned spacewalk to evaluate EVA techniques and gear for the Space Station Freedom (SSF). The CCT is located in JSC's Mockup and Integration Laboratory (MAIL) Bldg 9NE.

  10. Sex-specific mediation effect of the right fusiform face area volume on the association between variants in repeat length of AVPR1A RS3 and altruistic behavior in healthy adults.

    PubMed

    Wang, Junping; Qin, Wen; Liu, Feng; Liu, Bing; Zhou, Yuan; Jiang, Tianzi; Yu, Chunshui

    2016-07-01

    Microsatellite variants in the arginine vasopressin receptor 1A gene (AVPR1A) RS3 have been associated with normal social behaviors variation and autism spectrum disorders (ASDs) in a sex-specific manner. However, neural mechanisms underlying these associations remain largely unknown. We hypothesized that AVPR1A RS3 variants affect altruistic behavior by modulating the gray matter volume (GMV) of specific brain regions in a sex-specific manner. We investigated 278 young healthy adults using the Dictator Game to assess altruistic behavior. All subjects were genotyped and main effect of AVPR1A RS3 repeat polymorphisms and interaction of genotype-by-sex on the GMV were assessed in a voxel-wise manner. We observed that male subjects with relatively short repeats allocated less money to others and exhibited a significantly smaller GMV in the right fusiform face area (FFA) compared with male long homozygotes. In male subjects, the GMV of the right FFA exhibited a significant positive correlation with altruistic behavior. A mixed mediation and moderation analysis further revealed both a significant mediation effect of the GMV of the right FFA on the association between AVPR1A RS3 repeat polymorphisms and allocation sums and a significant moderation effect of sex (only in males) on the mediation effect. Post hoc analysis showed that the GMV of the right FFA was significantly smaller in male subjects carrying allele 426 than in non-426 carriers. These results suggest that the GMV of the right FFA may be a potential mediator whereby the genetic variants in AVPR1A RS3 affect altruistic behavior in healthy male subjects. Hum Brain Mapp 37:2700-2709, 2016. © 2016 Wiley Periodicals, Inc. PMID:27027249

  11. STS-38 Atlantis, OV-104, crewmembers on Bldg 9A CCT flight deck

    NASA Technical Reports Server (NTRS)

    1990-01-01

    STS-38 Atlantis, Orbiter Vehicle (OV) 104, crewmembers participate in training activities in the One Gravity Mockup and Training Facilities Bldg 9A crew compartment trainer (CCT). Commander Richard O. Covey, Pilot Frank L. Culbertson, Mission Specialist (MS) Robert C. Springer, MS Carl J. Meade, and MS Charles D. 'Sam' Gemar are suited in launch and entry suits (LESs) and seated on flight deck. In flight seating arrangement are (from left to right) Culbertson, Covey, Meade, Springer, and Gemar (standing).

  12. STS-41 MS Akers tumbles out of JSC's CCT during egress exercises

    NASA Technical Reports Server (NTRS)

    1990-01-01

    STS-41 Mission Specialist (MS) Thomas D. Akers, wearing a launch and entry suit (LES) and launch and entry helmet (LEH), tumbles out of JSC's crew compartment trainer (CCT) during side hatch emergency egress exercises. Using the crew escape system (CES) pole, Akers simulated the procedures necessary to bailout of the Shuttle during the ascent phase. A technician assists Akers, rolling across an inflated safety pad, as a second technician looks on. In the open side hatch, another crewmember prepares for egress.

  13. STS-47 Commander Gibson and Pilot Brown at CCT side hatch during JSC training

    NASA Technical Reports Server (NTRS)

    1992-01-01

    STS-47 Endeavour, Orbiter Vehicle (OV) 105, Spacelab Japan (SLJ) Commander Robert L. Gibson (right) and Pilot Curtis L. Brown, Jr, wearing launch and entry suits (LESs), pose in front of the Crew Compartment Trainer (CCT) mockup side hatch during post landing emergency egress procedures held at JSC's Mockup and Integration Laboratory (MAIL) Bldg 9NE. Note that the crew escape system (CES) pole is in position at side hatch but is not extended.

  14. STS-34 crewmembers review IFM procedures on JSC's CCT mockup middeck

    NASA Technical Reports Server (NTRS)

    1989-01-01

    STS-34 crewmembers review inflight maintenance (IFM) procedures on the middeck of JSC's crew compartment trainer (CCT) located in the Mockup and Integration Laboratory (MAIL) Bldg 9A. IFM trainer, holding cable, discusses procedures with Mission Specialist (MS) Ellen S. Baker (center) and Pilot Michael J. McCulley. An open stowage locker appears in front of the group. Visible on the mockup's middeck are forward and aft stowage lockers, the airlock hatch, and the starboard wall mounted sleep restraints.

  15. STS-38 MS Springer climbs through CCT side hatch prior to egress training

    NASA Technical Reports Server (NTRS)

    1990-01-01

    STS-38 Mission Specialist (MS) Robert C. Springer, wearing launch and entry suit (LES), climbs through the side hatch of the crew compartment trainer (CCT) located in JSC's Mockup and Integration Laboratory (MAIL) Bldg 9A. Springer will practice emergency egress through the side hatch using the crew escape system (CES) pole (at Springer's left). The inflated safety cushion under Springer will break his fall as he rolls out of the side hatch.

  16. STS-38 Pilot Culbertson rolls through CCT side hatch during egress training

    NASA Technical Reports Server (NTRS)

    1990-01-01

    STS-38 Pilot Frank L. Culbertson, wearing launch and entry suit (LES) and launch and entry helmet (LEH), rolls through the side hatch of the crew compartment trainer (CCT) located in JSC's Mockup and Integration Laboratory (MAIL) Bldg 9A. Assisted by technicians, Culbertson practices emergency egress through the side hatch using the crew escape system (CES) pole which extends out the side hatch. The inflated safety cushion breaks Culbertson's fall as he rolls out of the side hatch.

  17. STS-49 MS Thornton, in LES, at the CCT side hatch during JSC egress exercises

    NASA Technical Reports Server (NTRS)

    1992-01-01

    STS-49 Endeavour, Orbiter Vehicle (OV) 105, Mission Specialist (MS) Kathryn C. Thornton, wearing launch and entry suit (LES) and with foot propped on open side hatch, prepares to enter JSC's Crew Compartment Trainer (CCT) located in the Mockup and Integration Laboratory (MAIL) Bldg 9. Thornton along with other STS-49 crewmembers is participating in post-landing emergency egress training. Photo taken by NASA JSC contract photographer Mark Sowa.

  18. CACTA-like transposable element in ZmCCT attenuated photoperiod sensitivity and accelerated the postdomestication spread of maize

    PubMed Central

    Yang, Qin; Li, Zhi; Li, Wenqiang; Ku, Lixia; Wang, Chao; Ye, Jianrong; Li, Kun; Yang, Ning; Li, Yipu; Zhong, Tao; Li, Jiansheng; Chen, Yanhui; Yan, Jianbing; Yang, Xiaohong; Xu, Mingliang

    2013-01-01

    The postdomestication adaptation of maize to longer days required reduced photoperiod sensitivity to optimize flowering time. We performed a genome-wide association study and confirmed that ZmCCT, encoding a CCT domain-containing protein, is associated with the photoperiod response. In early-flowering maize we detected a CACTA-like transposable element (TE) within the ZmCCT promoter that dramatically reduced flowering time. TE insertion likely occurred after domestication and was selected as maize adapted to temperate zones. This process resulted in a strong selective sweep within the TE-related block of linkage disequilibrium. Functional validations indicated that the TE represses ZmCCT expression to reduce photoperiod sensitivity, thus accelerating maize spread to long-day environments. PMID:24089449

  19. Preclinical pharmacology, antitumor activity, and development of pharmacodynamic markers for the novel, potent AKT inhibitor CCT128930.

    PubMed

    Yap, Timothy A; Walton, Mike I; Hunter, Lisa-Jane K; Valenti, Melanie; de Haven Brandon, Alexis; Eve, Paul D; Ruddle, Ruth; Heaton, Simon P; Henley, Alan; Pickard, Lisa; Vijayaraghavan, Gowri; Caldwell, John J; Thompson, Neil T; Aherne, Wynne; Raynaud, Florence I; Eccles, Suzanne A; Workman, Paul; Collins, Ian; Garrett, Michelle D

    2011-02-01

    AKT is frequently deregulated in cancer, making it an attractive anticancer drug target. CCT128930 is a novel ATP-competitive AKT inhibitor discovered using fragment- and structure-based approaches. It is a potent, advanced lead pyrrolopyrimidine compound exhibiting selectivity for AKT over PKA, achieved by targeting a single amino acid difference. CCT128930 exhibited marked antiproliferative activity and inhibited the phosphorylation of a range of AKT substrates in multiple tumor cell lines in vitro, consistent with AKT inhibition. CCT128930 caused a G(1) arrest in PTEN-null U87MG human glioblastoma cells, consistent with AKT pathway blockade. Pharmacokinetic studies established that potentially active concentrations of CCT128930 could be achieved in human tumor xenografts. Furthermore, CCT128930 also blocked the phosphorylation of several downstream AKT biomarkers in U87MG tumor xenografts, indicating AKT inhibition in vivo. Antitumor activity was observed with CCT128930 in U87MG and HER2-positive, PIK3CA-mutant BT474 human breast cancer xenografts, consistent with its pharmacokinetic and pharmacodynamic properties. A quantitative immunofluorescence assay to measure the phosphorylation and total protein expression of the AKT substrate PRAS40 in hair follicles is presented. Significant decreases in pThr246 PRAS40 occurred in CCT128930-treated mouse whisker follicles in vivo and human hair follicles treated ex vivo, with minimal changes in total PRAS40. In conclusion, CCT128930 is a novel, selective, and potent AKT inhibitor that blocks AKT activity in vitro and in vivo and induces marked antitumor responses. We have also developed a novel biomarker assay for the inhibition of AKT in human hair follicles, which is currently being used in clinical trials. PMID:21191045

  20. Preclinical pharmacology, antitumor activity and development of pharmacodynamic markers for the novel, potent AKT inhibitor CCT128930

    PubMed Central

    Yap, Timothy A.; Walton, Mike I.; Hunter, Lisa-Jane K.; Valenti, Melanie; de Haven Brandon, Alexis; Eve, Paul D.; Ruddle, Ruth; Heaton, Simon P.; Henley, Alan; Pickard, Lisa; Vijayaraghavan, Gowri; Caldwell, John J.; Thompson, Neil T.; Aherne, Wynne; Raynaud, Florence I.; Eccles, Suzanne A.; Workman, Paul; Collins, Ian; Garrett, Michelle D.

    2016-01-01

    AKT is frequently deregulated in cancer, making it an attractive anticancer drug target. CCT128930 is a novel ATP-competitive AKT inhibitor discovered using fragment and structure-based approaches. It is a potent, advanced lead pyrrolopyrimidine compound exhibiting selectivity for AKT over PKA, achieved by targeting a single amino acid difference. CCT128930 exhibited marked antiproliferative activity and inhibited the phosphorylation of a range of AKT substrates in multiple tumor cell lines in vitro, consistent with AKT inhibition. CCT128930 caused a G1 arrest in PTEN-null U87MG human glioblastoma cells, consistent with AKT pathway blockade. Pharmacokinetic studies established that potentially active concentrations of CCT128930 could be achieved in human tumor xenografts. Furthermore, CCT128930 also blocked the phosphorylation of several downstream AKT biomarkers in U87MG tumor xenografts, indicating AKT inhibition in vivo. Antitumor activity was observed with CCT128930 in U87MG and HER2-positive, PIK3CA-mutant BT474 human breast cancer xenografts, consistent with its pharmacokinetic and pharmacodynamic properties. A quantitative immunofluorescence assay to measure the phosphorylation and total protein expression of the AKT substrate PRAS40 in hair follicles is presented. Significant decreases in pThr246 PRAS40 occurred in CCT128930-treated mouse whisker follicles in vivo and human hair follicles treated ex vivo, with minimal changes in total PRAS40. In conclusion, CCT128930 is a novel, selective and potent AKT inhibitor, which blocks AKT activity in vitro and in vivo and induces marked antitumor responses. We have also developed a novel biomarker assay for the inhibition of AKT in human hair follicles, which is currently being employed in clinical trials. PMID:21191045

  1. Low-Temperature-Induced Expression of Rice Ureidoglycolate Amidohydrolase is Mediated by a C-Repeat/Dehydration-Responsive Element that Specifically Interacts with Rice C-Repeat-Binding Factor 3

    PubMed Central

    Li, Juan; Qin, Rui-Ying; Li, Hao; Xu, Rong-Fang; Yang, Ya-Chun; Ni, Da-Hu; Ma, Hui; Li, Li; Wei, Peng-Cheng; Yang, Jian-Bo

    2015-01-01

    Nitrogen recycling and redistribution are important for the environmental stress response of plants. In non-nitrogen-fixing plants, ureide metabolism is crucial to nitrogen recycling from organic sources. Various studies have suggested that the rate-limiting components of ureide metabolism respond to environmental stresses. However, the underlying regulation mechanism is not well understood. In this report, rice ureidoglycolate amidohydrolase (OsUAH), which is a recently identified enzyme catalyzing the final step of ureide degradation, was identified as low-temperature- (LT) but not abscisic acid- (ABA) regulated. To elucidate the LT regulatory mechanism at the transcriptional level, we isolated and characterized the promoter region of OsUAH (POsUAH). Series deletions revealed that a minimal region between –522 and –420 relative to the transcriptional start site was sufficient for the cold induction of POsUAH. Detailed analyses of this 103-bp fragment indicated that a C-repeat/dehydration-responsive (CRT/DRE) element localized at position –434 was essential for LT-responsive expression. A rice C-repeat-binding factors/DRE-binding proteins 1 (CBFs/DREB1s) subfamily member, OsCBF3, was screened to specifically bind to the CRT/DRE element in the minimal region both in yeast one-hybrid assays and in in vitro gel-shift analysis. Moreover, the promoter could be exclusively trans-activated by the interaction between the CRT/DRE element and OsCBF3 in vivo. These findings may help to elucidate the regulation mechanism of stress-responsive ureide metabolism genes and provide an example of the member-specific manipulation of the CBF/DREB1 subfamily. PMID:26617632

  2. Archive of Digital Chirp Sub-bottom Profile Data Collected During USGS Cruises 08CCT02 and 08CCT03, Mississippi Gulf Islands, July and September 2008

    USGS Publications Warehouse

    Barry, K.M.; Cavers, D.A.; Kneale, C.W.

    2011-01-01

    In July and September of 2008, the U.S. Geological Survey (USGS) conducted geophysical surveys to investigate the geologic controls on island framework from Ship Island to Horn Island, MS, for the Northern Gulf of Mexico (NGOM) Ecosystem Change and Hazard Susceptibility project. This project is also part of a broader USGS study on Coastal Change and Transport (CCT). This report serves as an archive of unprocessed digital Chirp sub-bottom profile data, trackline maps, navigation files, Geographic Information System (GIS) files, Field Activity Collection System (FACS) logs, observer's logbook, and formal Federal Geographic Data Committee (FGDC) metadata. Gained (a relative increase in signal amplitude) digital images of the sub-bottom profiles are also provided. Refer to the Acronyms page for expansion of acronyms and abbreviations used in this report.

  3. Direct repeat-mediated DNA deletion of the mating type MAT1-2 genes results in unidirectional mating type switching in Sclerotinia trifoliorum

    PubMed Central

    Xu, Liangsheng; Jardini, Teresa M.; Chen, Weidong

    2016-01-01

    The necrotrophic fungal pathogen Sclerotinia trifoliorum exhibits ascospore dimorphism and unidirectional mating type switching - self-fertile strains derived from large ascospores produce both self-fertile (large-spores) and self-sterile (small-spores) offsprings in a 4:4 ratio. The present study, comparing DNA sequences at MAT locus of both self-fertile and self-sterile strains, found four mating type genes (MAT1-1-1, MAT1-1-5, MAT1-2-1 and MAT1-2-4) in the self-fertile strain. However, a 2891-bp region including the entire MAT1-2-1 and MAT1-2-4 genes had been completely deleted from the MAT locus in the self-sterile strain. Meanwhile, two copies of a 146-bp direct repeat motif flanking the deleted region were found in the self-fertile strain, but only one copy of this 146-bp motif (a part of the MAT1-1-1 gene) was present in the self-sterile strain. The two direct repeats were believed to be responsible for the deletion through homologous intra-molecular recombination in meiosis. Tetrad analyses showed that all small ascospore-derived strains lacked the missing DNA between the two direct repeats that was found in all large ascospore-derived strains. In addition, heterokaryons at the MAT locus were observed in field isolates as well as in laboratory derived isolates. PMID:27255676

  4. Direct repeat-mediated DNA deletion of the mating type MAT1-2 genes results in unidirectional mating type switching in Sclerotinia trifoliorum.

    PubMed

    Xu, Liangsheng; Jardini, Teresa M; Chen, Weidong

    2016-01-01

    The necrotrophic fungal pathogen Sclerotinia trifoliorum exhibits ascospore dimorphism and unidirectional mating type switching - self-fertile strains derived from large ascospores produce both self-fertile (large-spores) and self-sterile (small-spores) offsprings in a 4:4 ratio. The present study, comparing DNA sequences at MAT locus of both self-fertile and self-sterile strains, found four mating type genes (MAT1-1-1, MAT1-1-5, MAT1-2-1 and MAT1-2-4) in the self-fertile strain. However, a 2891-bp region including the entire MAT1-2-1 and MAT1-2-4 genes had been completely deleted from the MAT locus in the self-sterile strain. Meanwhile, two copies of a 146-bp direct repeat motif flanking the deleted region were found in the self-fertile strain, but only one copy of this 146-bp motif (a part of the MAT1-1-1 gene) was present in the self-sterile strain. The two direct repeats were believed to be responsible for the deletion through homologous intra-molecular recombination in meiosis. Tetrad analyses showed that all small ascospore-derived strains lacked the missing DNA between the two direct repeats that was found in all large ascospore-derived strains. In addition, heterokaryons at the MAT locus were observed in field isolates as well as in laboratory derived isolates. PMID:27255676

  5. True ternary fission, the collinear cluster tripartition (CCT) of {sup 252}Cf

    SciTech Connect

    Oertzen, W. von; Pyatkov, Y. V.; Kamanin, D.

    2012-10-20

    In systematic work over the last decade (see Pyatkov et al. [12] and refs therein), the ternary fission decay of heavy nuclei, in {sup 235}U(n,fff) and {sup 252}Cf(sf) has been studied in a collinear geometry. The name used for this process is (CCT), with three fragments of similar size in a collinear decay, it is the true ternary fission. This decay has been observed in spontaneous fission as well as in a neutron induced reaction. The measurements are based on different experimental set-ups, with binary coincidences containing TOF and energy determinations. With two detector telescopes placed at 180 Degree-Sign , the measurements of masses and energies of each of the registered two fragments, give complete kinematic solutions. Thus the missing mass events in binary coincidences can be determined, these events are obtained by blocking one of the lighter fragments on a structure in front of the detectors. The relatively high yield of CCT (more than 10{sup -3} per binary fission) is explained. It is due to the favourable Q-values (more positive than for binary) and the large phase space of the ternary CCT-decay, dominated by three (magic) clusters: e.g. isotopes of Sn, Ca and Ni, {sup 132}Sn+{sup 50}Ca+{sup 70}Ni. It is shown that the collinear (prolate) geometry has the favoured potential energy relative to the oblate shapes. The ternary fission is considered to be a sequential process. With this assumption the kinetic energies of the fragments have been calculated by Vijay et al.. The third fragments have very low kinetic energies (below 20 MeV) and have thus escaped their detection in previous work on 'ternary fission', where in addition an oblate shape and a triangle for the momentum vectors have been assumed.

  6. Shuttle crew escape systems test conducted in JSC Bldg 9A CCT

    NASA Technical Reports Server (NTRS)

    1987-01-01

    Shuttle crew escape systems test is conducted by astronauts Steven R. Nagel (left) and Manley L. (Sonny) Carter in JSC One Gravity Mockup and Training Facilities Bldg 9A crew compartment trainer (CCT). Nagel and Carter are evaluating methods for crew escape during Space Shuttle controlled gliding flight. JSC test was done in advance of tests scheduled for facilities in California and Utah. Here, Carter serves as test subject evaluating egress positioning for the tractor rocket escape method - one of the two systems currently being closely studied by NASA.

  7. STS-36 Commander Creighton and Pilot Casper during egress training at JSC CCT

    NASA Technical Reports Server (NTRS)

    1989-01-01

    STS-36 Commander John O. Creighton (right) and Pilot John H. Casper, wearing launch and entry suits (LESs), pose for this photo before participating in emergency egress training in JSC's Mockup and Integration Laboratory (MAIL) Bldg 9A. Behind the crewmembers is the open side hatch of the crew compartment trainer (CCT), a shuttle mockup. The crewmembers will practice egress procedures necessary in the event of an emergency onboard the shuttle. Creighton and Casper are scheduled to fly aboard Atlantis, Orbiter Vehicle (OV) 104, for an upcoming Department of Defense (DOD) mission.

  8. STS-65 Japanese Payload Specialist Mukai at CCT side hatch during training

    NASA Technical Reports Server (NTRS)

    1993-01-01

    STS-65 Japanese Payload Specialist Chiaki Mukai takes a break from training at the Johnson Space Center (JSC). Wearing a training version of the orange launch and entry suit (LES), Mukai stands at the crew compartment trainer (CCT) side hatch in the Mockup and Integration Laboratory (MAIL) Bldg 9NE. Note the crew escape system (CES) pole device extending out the side hatch which would accommodate crewmembers in bailout from a troubled spacecraft. Mukai represents the National Space Development Agency (NASDA) of Japan and will serve as a payload specialist aboard Columbia, Orbiter Vehicle (OV) 102, during the STS-65 International Microgravity Laboratory 2 (IML-2) mission.

  9. Effects of Teacher-Mediated Repeated Viewings of Stories in American Sign Language on Classifier Production of Students Who Are Deaf or Hard of Hearing

    ERIC Educational Resources Information Center

    Beal-Alvarez, Jennifer

    2012-01-01

    Students who are deaf and use sign language frequently have language delays that affect their literacy skills. Students who use American Sign Language (ASL) often lack fluent language models in both the home and school settings, delaying both the development of a first language and the development of literacy in printed English. Mediated and…

  10. Potential for thermal coal and Clean Coal Technology (CCT) in the Asia-Pacific. Final technical report

    SciTech Connect

    Johnson, C.J.; Long, S.

    1991-11-22

    The Coal Project was able to make considerable progress in understanding the evolving energy situation in Asia and the future role of coal and Clean Coal Technologies. It is clear that there will be major growth in consumption of coal in Asia over the next two decades -- we estimate an increase of 1.2 billion metric tons. Second, all governments are concerned about the environmental impacts of increased coal use, however enforcement of regulations appears to be quite variable among Asian countries. There is general caution of the part of Asian utilities with respect to the introduction of CCT`s. However, there appears to be potential for introduction of CCT`s in a few countries by the turn of the century. It is important to emphasize that it will be a long term effort to succeed in getting CCT`s introduced to Asia. The Coal Project recommends that the US CCT program be expanded to allow the early introduction of CCT`s in a number of countries.

  11. Improvement of LysM-Mediated Surface Display of Designed Ankyrin Repeat Proteins (DARPins) in Recombinant and Nonrecombinant Strains of Lactococcus lactis and Lactobacillus Species

    PubMed Central

    Zadravec, Petra; Štrukelj, Borut

    2015-01-01

    Safety and probiotic properties make lactic acid bacteria (LAB) attractive hosts for surface display of heterologous proteins. Protein display on nonrecombinant microorganisms is preferred for therapeutic and food applications due to regulatory requirements. We displayed two designed ankyrin repeat proteins (DARPins), each possessing affinity for the Fc region of human IgG, on the surface of Lactococcus lactis by fusing them to the Usp45 secretion signal and to the peptidoglycan-binding C terminus of AcmA, containing lysine motif (LysM) repeats. Growth medium containing a secreted fusion protein was used to test its heterologous binding to 10 strains of species of the genus Lactobacillus, using flow cytometry, whole-cell enzyme-linked immunosorbent assay (ELISA), and fluorescence microscopy. The fusion proteins bound to the surfaces of all lactobacilli; however, binding to the majority of bacteria was only 2- to 5-fold stronger than that of the control. Lactobacillus salivarius ATCC 11741 demonstrated exceptionally strong binding (32- to 55-fold higher than that of the control) and may therefore be an attractive host for nonrecombinant surface display. Genomic comparison of the species indicated the exopolysaccharides of Lb. salivarius as a possible reason for the difference. Additionally, a 15-fold concentration-dependent increase in nonrecombinant surface display on L. lactis was demonstrated by growing bacteria with sublethal concentrations of the antibiotics chloramphenicol and erythromycin. Nonrecombinant surface display on LAB, based on LysM repeats, was optimized by selecting Lactobacillus salivarius ATCC 11741 as the optimal host and by introducing antibiotics as additives for increasing surface display on L. lactis. Additionally, effective display of DARPins on the surfaces of nonrecombinant LAB has opened up several new therapeutic possibilities. PMID:25576617

  12. Repeated dosing of ABT-102, a potent and selective TRPV1 antagonist, enhances TRPV1-mediated analgesic activity in rodents, but attenuates antagonist-induced hyperthermia.

    PubMed

    Honore, Prisca; Chandran, Prasant; Hernandez, Gricelda; Gauvin, Donna M; Mikusa, Joseph P; Zhong, Chengmin; Joshi, Shailen K; Ghilardi, Joseph R; Sevcik, Molly A; Fryer, Ryan M; Segreti, Jason A; Banfor, Patricia N; Marsh, Kennan; Neelands, Torben; Bayburt, Erol; Daanen, Jerome F; Gomtsyan, Arthur; Lee, Chih-Hung; Kort, Michael E; Reilly, Regina M; Surowy, Carol S; Kym, Philip R; Mantyh, Patrick W; Sullivan, James P; Jarvis, Michael F; Faltynek, Connie R

    2009-03-01

    Transient receptor potential vanilloid type 1 (TRPV1) is a ligand-gated ion channel that functions as an integrator of multiple pain stimuli including heat, acid, capsaicin and a variety of putative endogenous lipid ligands. TRPV1 antagonists have been shown to decrease inflammatory pain in animal models and to produce limited hyperthermia at analgesic doses. Here, we report that ABT-102, which is a potent and selective TRPV1 antagonist, is effective in blocking nociception in rodent models of inflammatory, post-operative, osteoarthritic, and bone cancer pain. ABT-102 decreased both spontaneous pain behaviors and those evoked by thermal and mechanical stimuli in these models. Moreover, we have found that repeated administration of ABT-102 for 5-12 days increased its analgesic activity in models of post-operative, osteoarthritic, and bone cancer pain without an associated accumulation of ABT-102 concentration in plasma or brain. Similar effects were also observed with a structurally distinct TRPV1 antagonist, A-993610. Although a single dose of ABT-102 produced a self-limiting increase in core body temperature that remained in the normal range, the hyperthermic effects of ABT-102 effectively tolerated following twice-daily dosing for 2 days. Therefore, the present data demonstrate that, following repeated administration, the analgesic activity of TRPV1 receptor antagonists is enhanced, while the associated hyperthermic effects are attenuated. The analgesic efficacy of ABT-102 supports its advancement into clinical studies. PMID:19135797

  13. Leucine-rich repeat kinase 2 binds to neuronal vesicles through protein interactions mediated by its C-terminal WD40 domain.

    PubMed

    Piccoli, Giovanni; Onofri, Franco; Cirnaru, Maria Daniela; Kaiser, Christoph J O; Jagtap, Pravinkumar; Kastenmüller, Andreas; Pischedda, Francesca; Marte, Antonella; von Zweydorf, Felix; Vogt, Andreas; Giesert, Florian; Pan, Lifeng; Antonucci, Flavia; Kiel, Christina; Zhang, Mingjie; Weinkauf, Sevil; Sattler, Michael; Sala, Carlo; Matteoli, Michela; Ueffing, Marius; Gloeckner, Christian Johannes

    2014-06-01

    Mutations in the leucine-rich repeat kinase 2 gene (LRRK2) are associated with familial and sporadic Parkinson's disease (PD). LRRK2 is a complex protein that consists of multiple domains, including predicted C-terminal WD40 repeats. In this study, we analyzed functional and molecular features conferred by the WD40 domain. Electron microscopic analysis of the purified LRRK2 C-terminal domain revealed doughnut-shaped particles, providing experimental evidence for its WD40 fold. We demonstrate that LRRK2 WD40 binds and sequesters synaptic vesicles via interaction with vesicle-associated proteins. In fact, a domain-based pulldown approach combined with mass spectrometric analysis identified LRRK2 as being part of a highly specific protein network involved in synaptic vesicle trafficking. In addition, we found that a C-terminal sequence variant associated with an increased risk of developing PD, G2385R, correlates with a reduced binding affinity of LRRK2 WD40 to synaptic vesicles. Our data demonstrate a critical role of the WD40 domain within LRRK2 function. PMID:24687852

  14. Leucine-Rich Repeat Kinase 2 Binds to Neuronal Vesicles through Protein Interactions Mediated by Its C-Terminal WD40 Domain

    PubMed Central

    Piccoli, Giovanni; Onofri, Franco; Cirnaru, Maria Daniela; Kaiser, Christoph J. O.; Jagtap, Pravinkumar; Kastenmüller, Andreas; Pischedda, Francesca; Marte, Antonella; von Zweydorf, Felix; Vogt, Andreas; Giesert, Florian; Pan, Lifeng; Antonucci, Flavia; Kiel, Christina; Zhang, Mingjie; Weinkauf, Sevil; Sattler, Michael; Sala, Carlo; Matteoli, Michela; Ueffing, Marius

    2014-01-01

    Mutations in the leucine-rich repeat kinase 2 gene (LRRK2) are associated with familial and sporadic Parkinson's disease (PD). LRRK2 is a complex protein that consists of multiple domains, including predicted C-terminal WD40 repeats. In this study, we analyzed functional and molecular features conferred by the WD40 domain. Electron microscopic analysis of the purified LRRK2 C-terminal domain revealed doughnut-shaped particles, providing experimental evidence for its WD40 fold. We demonstrate that LRRK2 WD40 binds and sequesters synaptic vesicles via interaction with vesicle-associated proteins. In fact, a domain-based pulldown approach combined with mass spectrometric analysis identified LRRK2 as being part of a highly specific protein network involved in synaptic vesicle trafficking. In addition, we found that a C-terminal sequence variant associated with an increased risk of developing PD, G2385R, correlates with a reduced binding affinity of LRRK2 WD40 to synaptic vesicles. Our data demonstrate a critical role of the WD40 domain within LRRK2 function. PMID:24687852

  15. Regulation of rat cortical 5-hydroxytryptamine2A-receptor mediated electrophysiological responses by repeated daily treatment with electroconvulsive shock or imipramine

    PubMed Central

    Marek, Gerard J.

    2008-01-01

    Down-regulation of 5-hydroxytryptamine2A (5-HT2A) receptors has been a consistent effect induced by most antidepressant drugs. In contrast, electroconvulsive shock (ECS) up-regulates the number of 5-HT2A receptor binding sites. However, the effects of antidepressants on 5-HT2A receptor-mediated responses on identified cells of the cerebral cortex has not been examined. The purpose of the present study was to compare the effects of the tricyclic antidepressant imipramine and ECS on 5-HT2A receptor-mediated electrophysiological responses involving glutamatergic and GABAergic neurotransmission in the rat medial prefrontal cortex (mPFC) and piriform cortex, respectively. The electrophysiological effects of activating 5-HT2A receptors was consistent with 5-HT2A receptor binding regulation for imipramine and ECS except for the mPFC where chronic ECS decreased the potency of 5-HT at a 5-HT2A receptor-mediated response. These findings are consistent with the general hypothesis that chronic antidepressant treatments shift the balance of serotonergic neurotransmission towards inhibitory effects in the cortex. PMID:18294819

  16. Archive of digital Chirp subbottom profile data collected during USGS cruises 09CCT03 and 09CCT04, Mississippi and Alabama Gulf Islands, June and July 2009

    USGS Publications Warehouse

    Forde, Arnell S.; Dadisman, Shawn V.; Flocks, James G.; Wiese, Dana S.

    2011-01-01

    In June and July of 2009, the U.S. Geological Survey (USGS) conducted geophysical surveys to investigate the geologic controls on island framework from Cat Island, Mississippi, to Dauphin Island, Alabama, as part of a broader USGS study on Coastal Change and Transport (CCT). The surveys were funded through the Northern Gulf of Mexico Ecosystem Change and Hazard Susceptibility Project as part of the Holocene Evolution of the Mississippi-Alabama Region Subtask (http://ngom.er.usgs.gov/task2_2/index.php). This report serves as an archive of unprocessed digital Chirp seismic profile data, trackline maps, navigation files, Geographic Information System (GIS) files, Field Activity Collection System (FACS) logs, and formal Federal Geographic Data Committee (FGDC) metadata. Single-beam and Swath bathymetry data were also collected during these cruises and will be published as a separate archive. Gained (a relative increase in signal amplitude) digital images of the seismic profiles are also provided. Refer to the Acronyms page for expansion of acronyms and abbreviations used in this report.

  17. Cdc48p interacts with Ufd3p, a WD repeat protein required for ubiquitin-mediated proteolysis in Saccharomyces cerevisiae.

    PubMed Central

    Ghislain, M; Dohmen, R J; Levy, F; Varshavsky, A

    1996-01-01

    A library of random 10 residue peptides fused to the N-terminus of a reporter protein was screened in the yeast Saccharomyces cerevisiae for sequences that can target the reporter for degradation by the N-end rule pathway, a ubiquitin (Ub)-dependent proteolytic system that recognizes potential substrates through binding to their destabilizing N-terminal residues. One of the N-terminal sequences identified by this screen was used in a second screen for mutants incapable of degrading the corresponding reporter fusion. A mutant thus identified had an abnormally low content of free Ub. This mutant was found to be allelic to a previously isolated mutant in a Ub-dependent proteolytic system distinct from the N-end rule pathway. We isolated the gene involved, termed UFD3, which encodes an 80 kDa protein containing tandem repeats of a motif that is present in many eukaryotic proteins and called the WD repeat. Both co-immunoprecipitation and two-hybrid assays demonstrated that Ufd3p is an in vivo ligand of Cdc48p, an essential ATPase required for the cell cycle progression and the fusion of endoplasmic reticulum membranes. Further, we showed that, similarly to Ufd3p, Cdc48p is also required for the Ub-dependent proteolysis of test substrates. The discovery of the Ufd3p--Cdc48p complex and the finding that this complex is a part of the Ub system open up a new direction for studies of the function of Ub in the cell cycle and membrane dynamics. Images PMID:8890162

  18. KEY COMPARISON: Final Report on CCT-K7: Key comparison of water triple point cells

    NASA Astrophysics Data System (ADS)

    Stock, M.; Solve, S.; del Campo, D.; Chimenti, V.; Méndez-Lango, E.; Liedberg, H.; Steur, P. P. M.; Marcarino, P.; Dematteis, R.; Filipe, E.; Lobo, I.; Kang, K. H.; Gam, K. S.; Kim, Y.-G.; Renaot, E.; Bonnier, G.; Valin, M.; White, R.; Dransfield, T. D.; Duan, Y.; Xiaoke, Y.; Strouse, G.; Ballico, M.; Sukkar, D.; Arai, M.; Mans, A.; de Groot, M.; Kerkhof, O.; Rusby, R.; Gray, J.; Head, D.; Hill, K.; Tegeler, E.; Noatsch, U.; Duris, S.; Kho, H. Y.; Ugur, S.; Pokhodun, A.; Gerasimov, S. F.

    2006-01-01

    The triple point of water serves to define the kelvin, the unit of thermodynamic temperature, in the International System of Units (SI). Furthermore, it is the most important fixed point of the International Temperature Scale of 1990 (ITS-90). Any uncertainty in the realization of the triple point of water contributes directly to the measurement uncertainty over the wide temperature range from 13.8033 K to 1234.93 K. The Consultative Committee for Thermometry (CCT) decided at its 21st meeting in 2001 to carry out a comparison of water triple point cells and charged the BIPM with its organization. Water triple point cells from 20 national metrology institutes were carried to the BIPM and were compared with highest accuracy with two reference cells. The small day-to-day changes of the reference cells were determined by a least-squares technique. Prior to the measurements at the BIPM, the transfer cells were compared with the corresponding national references and therefore also allow comparison of the national references of the water triple point. This report presents the results of this comparison and gives detailed information about the measurements made at the BIPM and in the participating laboratories. It was found that the transfer cells show a standard deviation of 50 µK the difference between the extremes is 160 µK. The same spread is observed between the national references. The most important result of this work is that a correlation between the isotopic composition of the cell water and the triple point temperature was observed. To reduce the spread between different realizations, it is therefore proposed that the definition of the kelvin should refer to water of a specified isotopic composition. The CCT recommended to the International Committee of Weights and Measures (CIPM) to clarify the definition of the kelvin in the SI brochure by explicitly referring to water with the isotopic composition of Vienna Standard Mean Ocean Water (VSMOW). The CIPM

  19. The safety profile of a cationic lipid-mediated cystic fibrosis gene transfer agent following repeated monthly aerosol administration to sheep.

    PubMed

    Alton, Eric W F W; Baker, Alison; Baker, Eilidh; Boyd, A Christopher; Cheng, Seng H; Coles, Rebecca L; Collie, D David S; Davidson, Heather; Davies, Jane C; Gill, Deborah R; Gordon, Catherine; Griesenbach, Uta; Higgins, Tracy; Hyde, Stephen C; Innes, J Alastair; McCormick, Dominique; McGovern, Michael; McLachlan, Gerry; Porteous, David J; Pringle, Ian; Scheule, Ronald K; Shaw, Darren J; Smith, Sionagh; Sumner-Jones, Stephanie G; Tennant, Peter; Vrettou, Christina

    2013-12-01

    Clinically effective gene therapy for Cystic Fibrosis has been a goal for over 20 years. A plasmid vector (pGM169) that generates persistent expression and reduced host inflammatory responses in mice has raised prospects for translation to the clinic. The UK CF Gene Therapy Consortium is currently evaluating long-term repeated delivery of pGM169 complexed with the cationic lipid GL67A in a large Multidose Trial. This regulatory-compliant evaluation of aerosol administration of nine doses of pGM169/GL67A at monthly intervals, to the sheep lung, was performed in preparation for the Multidose Trial. All sheep tolerated treatment well with no adverse effects on haematology, serum chemistry, lung function or histopathology. Acute responses were observed in relation to bronchoalveolar cellularity comprising increased neutrophils and macrophage numbers 1 day post-delivery but these increases were transient and returned to baseline. Importantly there was no cumulative inflammatory effect or lung remodelling with successive doses. Molecular analysis confirmed delivery of pGM169 DNA to the airways and pGM169-specific mRNA was detected in bronchial brushing samples at day 1 following doses 1, 5 and 9. In conclusion, nine doses of pGM169/GL67A were well tolerated with no significant evidence of toxicity that would preclude adoption of a similar strategy in CF patients. PMID:24090839

  20. Clustered regulatory interspaced short palindromic repeats (CRISPR)-mediated mutagenesis and phenotype rescue by piggyBac transgenesis in a nonmodel Drosophila species.

    PubMed

    Tanaka, R; Murakami, H; Ote, M; Yamamoto, D

    2016-08-01

    How behavioural diversity emerged in evolution is an unexplored subject in biology. To tackle this problem, genes and circuits for a behaviour need to be determined in different species for phylogenetic comparisons. The recently developed clustered regulatory interspaced short palindromic repeats/CRISPR associated protein9 (CRISPR/Cas9) system made such a challenge possible by providing the means to induce mutations in a gene of interest in any organism. Aiming at elucidating diversification in genetic and neural networks for courtship behaviour, we attempted to generate a genetic tool kit in Drosophila subobscura, a nonmodel species distantly related to the genetic model Drosophila melanogaster. Here we report the generation of yellow (y) and white mutations with the aid of the CRISPR/Cas9 system, and the rescue of the y mutant phenotype by germline transformation of the newly established y mutant fly line with a y(+) -marked piggyBac vector. This successful mutagenesis and transformation in D. subobscura open up an avenue for comprehensive genetic analyses of higher functions in this and other nonmodel Drosophila species, representing a key step toward systematic comparisons of genes and circuitries underlying behaviour amongst species. PMID:27015359

  1. The molecular architecture of the eukaryotic chaperonin TRiC/CCT

    PubMed Central

    Leitner, Alexander; Joachimiak, Lukasz A.; Bracher, Andreas; Mönkemeyer, Leonie; Walzthoeni, Thomas; Chen, Bryan; Pechmann, Sebastian; Holmes, Susan; Cong, Yao; Ma, Boxue; Ludtke, Steve; Chiu, Wah; Hartl, F. Ulrich; Aebersold, Ruedi; Frydman, Judith

    2012-01-01

    Summary TRiC/CCT is a highly conserved and essential chaperonin that uses ATP cycling to facilitate folding of approximately 10% of the eukaryotic proteome. This 1 MDa hetero-oligomeric complex consists of two stacked rings of eight paralogous subunits each. Previously proposed TRiC models differ substantially in their subunit arrangements and ring register. Here, we integrate chemical crosslinking, mass spectrometry and combinatorial modeling to reveal the definitive subunit arrangement of TRiC. In vivo disulfide mapping provided additional validation for the crosslinking-derived arrangement as the definitive TRiC topology. This subunit arrangement allowed the refinement of a structural model using existing X-ray diffraction data. The new structure explains all available crosslink experiments, provides a rationale for previously unexplained structural features and reveals a surprising asymmetry of charges within the chaperonin folding chamber. PMID:22503819

  2. Energy Saving Melting and Revert Reduction Technology (Energy SMARRT): Development of CCT Diagrams

    SciTech Connect

    Chumbley, L Scott

    2011-08-20

    One of the most energy intensive industries in the U.S. today is in the melting and casting of steel alloys for use in our advanced technological society. While the majority of steel castings involve low or mild carbon steel for common construction materials, highly-alloyed steels constitute a critical component of many industries due to their excellent properties. However, as the amount of alloying additions increases, the problems associated with casting these materials also increases, resulting in a large waste of energy due to inefficiency and a lack of basic information concerning these often complicated alloy systems. Superaustenitic stainless steels constitute a group of Fe-based alloys that are compositionally balanced to have a purely austenitic matrix and exhibit favorable pitting and crevice corrosion resistant properties and mechanical strength. However, intermetallic precipitates such as sigma (³) and Laves can form during casting or exposure to high-temperature processing, which degrade the corrosion and mechanical properties of the material. Knowledge of the times and temperatures at which these detrimental phases form is imperative if a company is to efficiently produce castings of high quality in the minimum amount of time, using the lowest amount of energy possible, while producing the least amount of material waste. Anecdotal evidence from company representatives revealed that large castings frequently had to be scrapped due to either lower than expected corrosion resistance or extremely low fracture toughness. It was suspected that these poor corrosion and / or mechanical properties were directly related to the type, amount, and location of various intermetallic phases that formed during either the cooling cycle of the castings or subsequent heat treatments. However, no reliable data existed concerning either the time-temperature-transformation (TTT) diagrams or the continuous-cooling-transformation (CCT) diagrams of the super-austenitics. The

  3. Progress report for the CCT-WG5 high temperature fixed point research plan

    SciTech Connect

    Machin, G.; Woolliams, E. R.; Anhalt, K.; Bloembergen, P.; Sadli, M.; Yamada, Y.

    2013-09-11

    An overview of the progress in High Temperature Fixed Point (HTFP) research conducted under the auspices of the CCT-WG5 research plan is reported. In brief highlights are: Provisional long term stability of HTFPs has been demonstrated. Optimum construction methods for HTFPs have been established and high quality HTFPs of Co-C, Pt-C and Re-C have been constructed for thermodynamic temperature assignment. The major sources of uncertainty in the assignment of thermodynamic temperature have been identified and quantified. The status of absolute radiometric temperature measurement has been quantified through the circulation of a set of HTFPs. The measurement campaign to assign low uncertainty thermodynamic temperatures to a selected set of HTFPs will begin in mid-2012. It is envisaged that this will be complete by 2015 leading to HTFPs becoming routine reference standards for radiometry and high temperature metrology.

  4. STS-36 crewmembers in LESs pose for portrait on JSC's CCT flight deck

    NASA Technical Reports Server (NTRS)

    1989-01-01

    STS-36 Atlantis, Orbiter Vehicle (OV) 104, crewmembers, wearing launch and entry suits (LESs) and launch and entry helmets (LEHs), are stationed in their assigned positions on the flight deck of the crew compartment trainer (CCT) during a simulation at JSC's Mockup and Integration Laboratory (MAIL) Bldg 9A. On the forward flight deck are Commander John O. Creighton at the commanders station (far right) and Pilot John H. Casper at the pilots station (far left). Seated behind them in the mission specialists seats on the aft flight deck are Mission Specialist (MS) Pierre J. Thout (left) and MS David C. Hilmers (center). MS Richard M. Mullane stands since his seat is on the middeck. He joined the crew on the flight deck for this portrait taken with a fisheye lens.

  5. STS-65 payload specialists Favier and Mukai on CCT middeck during training

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Attired in launch and entry suits (LESs) and launch and entry helmets (LEHs) and seated on the Crew Compartment Trainer (CCT) middeck, payload specialists Jean-Jacques Favier and Chiaki Mukai rehearse launch and entry procedures. Favier of the French space agency, Centre National D'Etudes Spatiales (CNES), is backup for Mukai, the payload specialist representing the National Space Development Agency (NASDA) of Japan. Favier will communicate with the International Microgravity Laboratory 2's (IML-2's) crew from the ground during the scheduled 13-day flight. The two joined six NASA astronauts at Johnson Space Center's (JSC's) Mockup and Integration Laboratory (MAIL) Bldg 9NE for the training session. The STS-65 IML-2 mission will fly aboard Columbia, Orbiter Vehicle (OV) 102, next year.

  6. Clustered Regularly Interspaced Short Palindromic Repeat-Dependent, Biofilm-Specific Death of Pseudomonas aeruginosa Mediated by Increased Expression of Phage-Related Genes

    PubMed Central

    Heussler, Gary E.; Cady, Kyle C.; Koeppen, Katja; Bhuju, Sabin; Stanton, Bruce A.

    2015-01-01

    ABSTRACT The clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated (CRISPR/Cas) system is an adaptive immune system present in many archaea and bacteria. CRISPR/Cas systems are incredibly diverse, and there is increasing evidence of CRISPR/Cas systems playing a role in cellular functions distinct from phage immunity. Previously, our laboratory reported one such alternate function in which the type 1-F CRISPR/Cas system of the opportunistic pathogen Pseudomonas aeruginosa strain UCBPP-PA14 (abbreviated as P. aeruginosa PA14) inhibits both biofilm formation and swarming motility when the bacterium is lysogenized by the bacteriophage DMS3. In this study, we demonstrated that the presence of just the DMS3 protospacer and the protospacer-adjacent motif (PAM) on the P. aeruginosa genome is necessary and sufficient for this CRISPR-dependent loss of these group behaviors, with no requirement of additional DMS3 sequences. We also demonstrated that the interaction of the CRISPR system with the DMS3 protospacer induces expression of SOS-regulated phage-related genes, including the well-characterized pyocin operon, through the activity of the nuclease Cas3 and subsequent RecA activation. Furthermore, our data suggest that expression of the phage-related genes results in bacterial cell death on a surface due to the inability of the CRISPR-engaged strain to downregulate phage-related gene expression, while these phage-related genes have minimal impact on growth and viability under planktonic conditions. Deletion of the phage-related genes restores biofilm formation and swarming motility while still maintaining a functional CRISPR/Cas system, demonstrating that the loss of these group behaviors is an indirect effect of CRISPR self-targeting. PMID:25968642

  7. Accumulation of Heterochromatin Components on the Terminal Repeat Sequence of Kaposi's Sarcoma-Associated Herpesvirus Mediated by the Latency-Associated Nuclear Antigen

    PubMed Central

    Sakakibara, Shuhei; Ueda, Keiji; Nishimura, Ken; Do, Eunju; Ohsaki, Eriko; Okuno, Toshiomi; Yamanishi, Koichi

    2004-01-01

    In the latent infection of Kaposi's sarcoma-associated herpesvirus (KSHV), its 160-kb circularized episomal DNA is replicated and maintained in the host nucleus. KSHV latency-associated nuclear antigen (LANA) is a key factor for maintaining viral latency. LANA binds to the terminal repeat (TR) DNA of the viral genome, leading to its localization to specific dot structures in the nucleus. In such an infected cell, the expression of the viral genes is restricted by a mechanism that is still unclear. Here, we found that LANA interacts with SUV39H1 histone methyltransferase, a key component of heterochromatin formation, as determined by use of a DNA pull-down assay with a biotinylated DNA fragment that contained a LANA-specific binding sequence and a maltose-binding protein pull-down assay. The diffuse localization of LANA on the chromosomes of uninfected cells changed to a punctate one with the introduction of a bacterial artificial chromosome containing most of the TR region, and SUV39H1 clearly colocalized with the LANA-associated dots. Thus, the LANA foci in KSHV-infected cells seemed to include SUV39H1 as well as heterochromatin protein 1. Furthermore, a chromatin immunoprecipitation assay revealed that the TR and the open reading frame (ORF) K1 and ORF50/RTA genes, but not the ORF73/LANA gene, lay within the heterochromatin during KSHV latency. Taken together, these observations indicate that LANA recruits heterochromatin components to the viral genome, which may lead to the establishment of viral latency and govern the transcription program. PMID:15220403

  8. The Coxiella burnetii Ankyrin Repeat Domain-Containing Protein Family Is Heterogeneous, with C-Terminal Truncations That Influence Dot/Icm-Mediated Secretion ▿

    PubMed Central

    Voth, Daniel E.; Howe, Dale; Beare, Paul A.; Vogel, Joseph P.; Unsworth, Nathan; Samuel, James E.; Heinzen, Robert A.

    2009-01-01

    Coxiella burnetii is an obligate intracellular bacterium that directs biogenesis of a parasitophorous vacuole (PV) for replication. Effectors of PV maturation are likely translocated into the host cytosol by a type IV secretion system (T4SS) with homology to the Dot/Icm apparatus of Legionella pneumophila. Since secreted bacterial virulence factors often functionally mimic the activities of host proteins, prokaryotic proteins with eukaryotic features are considered candidate T4SS substrates. Genes encoding proteins with eukaryotic-type ankyrin repeat domains (Anks) were identified upon genome sequencing of the C. burnetii Nine Mile reference isolate, which is associated with a case of human acute Q fever. Interestingly, recent genome sequencing of the G and K isolates, derived from human chronic endocarditis patients, and of the Dugway rodent isolate revealed remarkable heterogeneity in the Ank gene family, with the Dugway isolate harboring the largest number of full-length Ank genes. Using L. pneumophila as a surrogate host, we identified 10 Dugway Anks and 1 Ank specific to the G and K endocarditis isolates translocated into the host cytosol in a Dot/Icm-dependent fashion. A 10-amino-acid C-terminal region appeared to be necessary for translocation, with some Anks also requiring the chaperone IcmS for secretion. Ectopically expressed Anks localized to a variety of subcellular regions in mammalian cells, including microtubules, mitochondria, and the PV membrane. Collectively, these data suggest that C. burnetii isolates translocate distinct subsets of the Ank protein family into the host cytosol, where they modulate diverse functions, some of which may be unique to C. burnetii pathotypes. PMID:19411324

  9. Reflections on the Looking at Student Work Project of the Center for Arts Education 2003. CCT Reports

    ERIC Educational Resources Information Center

    Baker, Terry L.

    2004-01-01

    The 2002-2003 meetings of the Looking at Student Work project (LASW) represent a new phase of the project featuring new organizing principles and practices. Previous year's sessions were observed and documented by EDC/CCT research staff and by Center for Arts Education (CAE) staff. Because the 2002-2003 version of the project introduced new…

  10. A novel third type of recurrent NF1 microdeletion mediated by nonallelic homologous recombination between LRRC37B-containing low-copy repeats in 17q11.2.

    PubMed

    Bengesser, Kathrin; Cooper, David N; Steinmann, Katharina; Kluwe, Lan; Chuzhanova, Nadia A; Wimmer, Katharina; Tatagiba, Marcos; Tinschert, Sigrid; Mautner, Victor-Felix; Kehrer-Sawatzki, Hildegard

    2010-06-01

    Large microdeletions encompassing the neurofibromatosis type-1 (NF1) gene and its flanking regions at 17q11.2 belong to the group of genomic disorders caused by aberrant recombination between segmental duplications. The most common NF1 microdeletions (type-1) span 1.4-Mb and have breakpoints located within NF1-REPs A and C, low-copy repeats (LCRs) containing LRRC37-core duplicons. We have identified a novel type of recurrent NF1 deletion mediated by nonallelic homologous recombination (NAHR) between the highly homologous NF1-REPs B and C. The breakpoints of these approximately 1.0-Mb ("type-3") NF1 deletions were characterized at the DNA sequence level in three unrelated patients. Recombination regions, spanning 275, 180, and 109-bp, respectively, were identified within the LRRC37B-P paralogues of NF1-REPs B and C, and were found to contain sequences capable of non-B DNA formation. Both LCRs contain LRRC37-core duplicons, abundant and highly dynamic sequences in the human genome. NAHR between LRRC37-containing LCRs at 17q21.31 is known to have mediated the 970-kb polymorphic inversions of the MAPT-locus that occurred independently in different primate species, but also underlies the syndromes associated with recurrent 17q21.31 microdeletions and reciprocal microduplications. The novel NF1 microdeletions reported here provide further evidence for the unusually high recombinogenic potential of LRRC37-containing LCRs in the human genome. PMID:20506354

  11. Time-dependent effects of repeated THC treatment on dopamine D2/3 receptor-mediated signalling in midbrain and striatum.

    PubMed

    Tournier, Benjamin B; Tsartsalis, Stergios; Dimiziani, Andrea; Millet, Philippe; Ginovart, Nathalie

    2016-09-15

    This study examined the time-course of alterations in levels and functional sensitivities of dopamine D2/3 receptors (D2/3R) during the course and up to 6 weeks following cessation of chronic treatment with Delta(9)-Tetrahydrocannabinol (THC) in rats. THC treatment led to an increase in D2/3R levels in striatum, as assessed using [(3)H]-(+)-PHNO, that was readily observable after one week of treatment, remained stably elevated during the subsequent 2 weeks of treatment, but fully reversed within 2 weeks of THC discontinuation. THC-induced D2/3R alterations were more pronounced and longer lasting in the dopamine cell body regions of the midbrain, wherein [(3)H]-(+)-PHNO binding was still elevated at 2 weeks but back to control values at 6 weeks after THC cessation. Parallel analyses of the psychomotor effects of pre- and post-synaptic doses of quinpirole also showed a pattern of D2/3R functional supersensitivity indicative of more rapid subsidence in striatum than in midbrain following drug cessation. These results indicate that chronic THC is associated with a biochemical and functional sensitization of D2/3R signaling, that these responses show a region-specific temporal pattern and are fully reversible following drug discontinuation. These results suggest that an increased post-synaptic D2/3R function and a decreased DA presynaptic signaling, mediated by increased D2/3R autoinhibition, may predominate during distinct phases of withdrawal and may contribute both to the mechanisms leading to relapse and to cannabinoid withdrawal symptoms. The different rates of normalization of D2/3R function in striatum and midbrain may be critical information for the development of new pharmacotherapies for cannabis dependence. PMID:27233824

  12. Comparative proteomic analysis of the shoot apical meristem in maize between a ZmCCT-associated near-isogenic line and its recurrent parent.

    PubMed

    Wu, Liuji; Wang, Xintao; Wang, Shunxi; Wu, Liancheng; Tian, Lei; Tian, Zhiqiang; Liu, Ping; Chen, Yanhui

    2016-01-01

    The ZmCCT, one of the most important genes affecting photoperiod response, delays flowering under long-day conditions in maize (Zea mays). In this study we used the isobaric tags for relative and absolute quantification (iTRAQ) technique-based proteomics approach to identify differentially expressed proteins between a near-isogenic line (NIL) and its recurrent parent, contrasting in alleles of ZmCCT. A total of 5,259 distinct proteins were identified. Among them, 386 proteins were differentially expressed between NIL-cml line (ZmCCT-positive) and H4 line (ZmCCT-negative). Functional categorization showed that the differentially proteins were mainly involved in energy production, photosynthesis, signal transduction, and cell organization and biogenesis. Our results showed that during shoot apical meristem (SAM) development cell division proteins, carbohydrate metabolism-related proteins, and flower inhibition-related proteins were more abundant in the ZmCCT-positive line than the ZmCCT-negative line. These results, taken together with morphological observations, showed that the effect of ZmCCT on flowering might be caused by its effect on one or all of these biological processes. Although the exact roles of these putative related proteins remain to be examined, our results obtained using the proteomics approach lead to a better understanding of the photoperiodicity mechanism in maize plants. PMID:27468931

  13. Comparative proteomic analysis of the shoot apical meristem in maize between a ZmCCT-associated near-isogenic line and its recurrent parent

    PubMed Central

    Wu, Liuji; Wang, Xintao; Wang, Shunxi; Wu, Liancheng; Tian, Lei; Tian, Zhiqiang; Liu, Ping; Chen, Yanhui

    2016-01-01

    The ZmCCT, one of the most important genes affecting photoperiod response, delays flowering under long-day conditions in maize (Zea mays). In this study we used the isobaric tags for relative and absolute quantification (iTRAQ) technique-based proteomics approach to identify differentially expressed proteins between a near-isogenic line (NIL) and its recurrent parent, contrasting in alleles of ZmCCT. A total of 5,259 distinct proteins were identified. Among them, 386 proteins were differentially expressed between NIL-cml line (ZmCCT-positive) and H4 line (ZmCCT-negative). Functional categorization showed that the differentially proteins were mainly involved in energy production, photosynthesis, signal transduction, and cell organization and biogenesis. Our results showed that during shoot apical meristem (SAM) development cell division proteins, carbohydrate metabolism–related proteins, and flower inhibition-related proteins were more abundant in the ZmCCT-positive line than the ZmCCT-negative line. These results, taken together with morphological observations, showed that the effect of ZmCCT on flowering might be caused by its effect on one or all of these biological processes. Although the exact roles of these putative related proteins remain to be examined, our results obtained using the proteomics approach lead to a better understanding of the photoperiodicity mechanism in maize plants. PMID:27468931

  14. Preparation and characterization of vanadia-titania mixed oxide for immobilization of Serratia rubidaea CCT 5732 and Klebsiella marcescens bacteria

    SciTech Connect

    Saragiotto Colpini, Leda Maria Correia Goncalves, Regina A.; Goncalves, Jose Eduardo; Maieru Macedo Costa, Creusa

    2008-08-04

    Vanadia-titania mixed oxide was synthesized by sol-gel method and characterized by several techniques. Texturally, it is formed by mesopores and presents high-specific surface area and controlled porosity. Scanning electron microscopy revealed that vanadium is homogeneously distributed in the material. Structurally, it was possible to identify characteristic V=O stretching bands by IR. The analysis of X-ray diffraction showed that the material, particularly vanadium, is highly dispersed. Application experiments were carried out through the immobilization of Serratia rubidae CCT 5732 and Klebsiella marcescens bacteria by adsorption on the surface of mixed oxide. The micrographies revealed that the bacteria were adsorbed on the entire support, with average surface densities of 8.55 x 10{sup 11} cells/m{sup 2} (Serratia rubidae CCT 5732) and 3.40 x 10{sup 11} cells/m{sup 2} (K. marcescens)

  15. Production and characterization of tyrosinase activity in Pycnoporus sanguineus CCT-4518 Crude extract

    PubMed Central

    Duarte, Lívia Teixeira; Tiba, Joyce Batista; Santiago, Mariângela Fontes; Garcia, Telma Alves; Freitas Bara, Maria Teresa

    2012-01-01

    Tyrosinase is an enzyme of industrial interest. The production and characterization of tyrosinase from P. sanguineus CCT-4518 were investigated. The selection of inductors, luminosity influence, inoculum size and type of culture medium on the production of tyrosinase and the effect of inhibitors on enzyme activity were performed. Optimum conditions for intracellular tyrosinase production was observed after 2 days using 0.15% L-tyrosine as inducer, in the presence of light, with inoculum size of 10 mycelium discs, using 2% malt extract broth medium, incubated at 30°C, and constant agitation of 150 rpm. Tyrosinase activity was completely inhibited by the addition of 6 mM salicylhydroxamic acid or phenylthiourea, however an inhibition of 4.15% was recorded by the addition of 0.1 mM sodium azide. No inhibition could be detected in case of 0.1 mM phenyl methanesulfonyl fluoride addition. Optimal conditions for intracellular tyrosinase activity using L-dopa as substrate were observed at pH 6.6 and 45°C. Thermal stability studies indicated that the enzyme is stable at 45°C for 15 minutes. Higher temperatures decreased tyrosinase activity. Enzyme production was confirmed by non-denaturing polyacrylamide gel electrophoresis and the protein profile was investigated by denaturing polyacrylamide gel electrophoresis. PMID:24031800

  16. The structural basis of substrate recognition by the eukaryotic chaperonin TRiC/CCT.

    PubMed

    Joachimiak, Lukasz A; Walzthoeni, Thomas; Liu, Corey W; Aebersold, Ruedi; Frydman, Judith

    2014-11-20

    The eukaryotic chaperonin TRiC (also called CCT) is the obligate chaperone for many essential proteins. TRiC is hetero-oligomeric, comprising two stacked rings of eight different subunits each. Subunit diversification from simpler archaeal chaperonins appears linked to proteome expansion. Here, we integrate structural, biophysical, and modeling approaches to identify the hitherto unknown substrate-binding site in TRiC and uncover the basis of substrate recognition. NMR and modeling provided a structural model of a chaperonin-substrate complex. Mutagenesis and crosslinking-mass spectrometry validated the identified substrate-binding interface and demonstrate that TRiC contacts full-length substrates combinatorially in a subunit-specific manner. The binding site of each subunit has a distinct, evolutionarily conserved pattern of polar and hydrophobic residues specifying recognition of discrete substrate motifs. The combinatorial recognition of polypeptides broadens the specificity of TRiC and may direct the topology of bound polypeptides along a productive folding trajectory, contributing to TRiC's unique ability to fold obligate substrates. PMID:25416944

  17. The structural basis of substrate recognition by the eukaryotic chaperonin TRiC/CCT

    PubMed Central

    Joachimiak, Lukasz A.; Walzthoeni, Thomas; Liu, Corey; Aebersold, Ruedi; Frydman, Judith

    2014-01-01

    Summary The eukaryotic chaperonin TRiC (also called CCT) is the obligate chaperone for many essential proteins. TRiC is hetero-oligomeric, comprising two stacked rings of eight different subunits each. Subunit diversification from simpler archaeal chaperonins appears linked to proteome expansion. Here, we integrate structural, biophysical and modeling approaches to identify the hitherto unknown substrate-binding site in TRiC and uncover the basis of substrate recognition. NMR and modeling provided a structural model of a chaperonin-substrate complex. Mutagenesis and crosslinking-mass spectrometry validated the identified substrate binding interface and demonstrate that TRiC contacts full-length substrates combinatorially in a subunit-specific manner. The binding site of each subunit has a distinct, evolutionarily conserved, pattern of polar and hydrophobic residues specifying recognition of discrete substrate motifs. The combinatorial recognition of polypeptides broadens the specificity of TRiC and may direct the topology of bound polypeptides along a productive folding trajectory, contributing to its unique ability to fold obligate substrates. PMID:25416944

  18. Edible films based on cassava starch and fructooligosaccharides produced by Bacillus subtilis natto CCT 7712.

    PubMed

    Bersaneti, Gabrielly Terassi; Mantovan, Janaina; Magri, Agnes; Mali, Suzana; Celligoi, Maria Antonia Pedrine Colabone

    2016-10-20

    The objectives of this work were to produce fructooligosaccharides (FOSs) by using the microorganism Bacillus subtilis natto CCT 7712 and to employ these FOSs as a functional ingredient in cassava starch edible films, which were characterized according to their microstructure, mechanical and barrier properties. The produced FOSs could be easily dissolved, resulting in homogeneous filmogenic solutions, which were easily manipulated to obtain films by casting. FOSs were added in different concentrations (0, 1, 5 and 10g/100g solids), and glycerol was used as a plasticizer (20g/100g solids). All formulations resulted in films that had a good appearance and were easily removable from the plates without bubbles or cracks. The FOSs exerted a plasticizing effect on the starch films and decreased their glass transition temperature. The addition of FOSs resulted in higher solubility and elongation and a decreased water vapor permeability of the films. FOSs were shown to be a promising ingredient for use in edible starch films. PMID:27474664

  19. LPS impairs phospholipid synthesis by triggering beta-transducin repeat-containing protein (beta-TrCP)-mediated polyubiquitination and degradation of the surfactant enzyme acyl-CoA:lysophosphatidylcholine acyltransferase I (LPCAT1).

    PubMed

    Zou, Chunbin; Butler, Phillip L; Coon, Tiffany A; Smith, Rebecca M; Hammen, Gary; Zhao, Yutong; Chen, Bill B; Mallampalli, Rama K

    2011-01-28

    Acyl-CoA:lysophosphatidylcholine acyltransferase 1 (LPCAT1) is a relatively newly described and yet indispensable enzyme needed for generation of the bioactive surfactant phospholipid, dipalmitoylphosphatidylcholine (DPPtdCho). Here, we show that lipopolysaccharide (LPS) causes LPCAT1 degradation using the Skp1-Cullin-F-box ubiquitin E3 ligase component, β-transducin repeat-containing protein (β-TrCP), that polyubiquitinates LPCAT1, thereby targeting the enzyme for proteasomal degradation. LPCAT1 was identified as a phosphoenzyme as Ser(178) within a phosphodegron was identified as a putative molecular recognition site for glycogen synthase kinase-3β (GSK-3β) phosphorylation that recruits β-TrCP docking within the enzyme. β-TrCP ubiquitinates LPCAT1 at an acceptor site (Lys(221)), as substitution of Lys(221) with Arg abrogated LPCAT1 polyubiquitination. LPS profoundly reduced immunoreactive LPCAT1 levels and impaired lung surfactant mechanics, effects that were overcome by siRNA to β-TrCP and GSK-3β or LPCAT1 gene transfer, respectively. Thus, LPS appears to destabilize the LPCAT1 protein by GSK-3β-mediated phosphorylation within a canonical phosphodegron for β-TrCP docking and site-specific ubiquitination. LPCAT1 is the first lipogenic substrate for β-TrCP, and the results suggest that modulation of the GSK-3β-SCFβ(TrCP) E3 ligase effector pathway might be a unique strategy to optimize dipalmitoylphosphatidylcholine levels in sepsis. PMID:21068446

  20. RNA-Seq Analysis of Oil Palm under Cold Stress Reveals a Different C-Repeat Binding Factor (CBF) Mediated Gene Expression Pattern in Elaeis guineensis Compared to Other Species

    PubMed Central

    Xia, Wei; Mason, Annaliese S.; Yang, Yaodong; Ma, Zilong; Peng, Ming

    2014-01-01

    Elaeis guineensis as a tropical oil-crop is particularly sensitive to low temperature. Improvement of cold-tolerance may significantly increase the total cultivation area of this tropical oil-crop worldwide. We sequenced cold-treated and control (untreated) samples of Elaeis guineensis. De novo assembly generated 51,452 unigenes with an average length of 703 bp. Subsequently, these expressed sequences were functionally annotated. In the K category (transcription factors) of COG (Cluster of Orthologous Group) annotation, the largest proportion of genes induced and repressed at least two-fold under cold stress were from the AP2/ERE family, indicating that C-repeat binding factor, (CBFs, members of the AP2/ERE family) may play a central role in cold tolerance in Elaeis guineensis. Subsequently, the CBF-mediated signal transduction pathway was reconstructed based on transcriptome data and the gene expression profile involving the pathway was examined using real-time quantitative RT-PCR (qRT-PCR). CBFs reached maximum transcript level both at medium (4 h) and long period time points (7 days), contrary to the expression pattern of CBFs in Arabidopsis and rice. Moreover, the promoters of downstream Cold Responsive gene (CORs) regulated by CBFs were analyzed. Conservation, mutation and absence of the DRE core motif were detected in the promoters of six CORs. These mutations in DRE motifs suggest that CORs may not be induced via cold stress in Elaeis guineensis. PMID:25479236

  1. RNA-seq analysis of oil palm under cold stress reveals a different C-repeat binding factor (CBF) mediated gene expression pattern in Elaeis guineensis compared to other species.

    PubMed

    Lei, Xintao; Xiao, Yong; Xia, Wei; Mason, Annaliese S; Yang, Yaodong; Ma, Zilong; Peng, Ming

    2014-01-01

    Elaeis guineensis as a tropical oil-crop is particularly sensitive to low temperature. Improvement of cold-tolerance may significantly increase the total cultivation area of this tropical oil-crop worldwide. We sequenced cold-treated and control (untreated) samples of Elaeis guineensis. De novo assembly generated 51,452 unigenes with an average length of 703 bp. Subsequently, these expressed sequences were functionally annotated. In the K category (transcription factors) of COG (Cluster of Orthologous Group) annotation, the largest proportion of genes induced and repressed at least two-fold under cold stress were from the AP2/ERE family, indicating that C-repeat binding factor, (CBFs, members of the AP2/ERE family) may play a central role in cold tolerance in Elaeis guineensis. Subsequently, the CBF-mediated signal transduction pathway was reconstructed based on transcriptome data and the gene expression profile involving the pathway was examined using real-time quantitative RT-PCR (qRT-PCR). CBFs reached maximum transcript level both at medium (4 h) and long period time points (7 days), contrary to the expression pattern of CBFs in Arabidopsis and rice. Moreover, the promoters of downstream Cold Responsive gene (CORs) regulated by CBFs were analyzed. Conservation, mutation and absence of the DRE core motif were detected in the promoters of six CORs. These mutations in DRE motifs suggest that CORs may not be induced via cold stress in Elaeis guineensis. PMID:25479236

  2. All Repeats are Not Equal: A Module-Based Approach to Guide Repeat Protein Design

    PubMed Central

    Regan, Lynne

    2013-01-01

    Repeat proteins composed of tandem arrays of a short structural motif often mediate protein-protein interactions. Past efforts to design repeat protein-based molecular recognition tools have focused on the creation of templates from the consensus of individual repeats, regardless of their natural context. Such an approach assumes that all repeats are essentially equivalent. In this study we present the results of a ‘module-based’ approach, in which modules composed of tandem repeats are aligned to identify repeat-specific features. Using this approach to analyze tetratricopeptide repeat modules that contain 3 tandem repeats (3TPRs), we identify two classes of 3TPR modules with distinct structural signatures that are correlated with different sets of functional residues. Our analyses also reveal a high degree of correlation between positions across the entire ligand-binding surface, indicative of a coordinated, coevolving binding surface. Extension of our analyses to different repeat protein modules reveals more examples of repeat-specific features, especially in armadillio repeat (ARM) modules. In summary, the module-based analyses that we present effectively capture key repeat-specific features that will be important to include in future repeat protein design templates. PMID:23434848

  3. CCT244747 is a novel, potent and selective CHK1 inhibitor with oral efficacy alone and in combination with genotoxic anticancer drugs

    PubMed Central

    Walton, Mike I; Eve, Paul D; Hayes, Angela; Valenti, Melanie R; De Haven Brandon, Alexis K; Box, Gary; Hallsworth, Albert; Smith, Elizabeth L; Boxall, Kathy J; Lainchbury, Michael; Matthews, Thomas P; Jamin, Yann; Robinson, Simon P; Aherne, G Wynne; Reader, John C; Chesler, Louis; Raynaud, Florence I; Eccles, Suzanne A; Collins, Ian; Garrett, Michelle D

    2012-01-01

    Purpose Many tumors exhibit defective cell cycle checkpoint control and increased replicative stress. CHK1 is critically involved in the DNA damage response and maintenance of replication fork stability. We have therefore discovered a novel, potent, highly selective, orally active, ATP competitive CHK1 inhibitor, CCT244747, and present its preclinical pharmacology and therapeutic activity. Experimental design Cellular CHK1 activity was assessed using an ELISA assay and cytotoxicity a SRB assay. Biomarker modulation was measured using immunoblotting and cell cycle effects by flow cytometry. Single agent, oral CCT244747 antitumor activity was evaluated in a MYCN-driven transgenic mouse model of neuroblastoma by MRI and in genotoxic combinations in human tumor xenografts by growth delay. Results CCT244747 inhibited cellular CHK1 activity (IC50 29-170nM), significantly enhanced the cytotoxicity of several anticancer drugs and abrogated drug-induced S and G2 arrest in multiple tumor cell lines. Biomarkers of CHK1 (pS296 CHK1) activity and cell cycle inactivity (pY15 CDK1) were induced by genotoxics and inhibited by CCT244747 both in vitro and in vivo, producing enhanced DNA damage and apoptosis. Active tumor concentrations of CCT244747 were obtained following oral administration. The antitumor activity of both gemcitabine and irinotecan were significantly enhanced by CCT244747 in several human tumor xenografts, giving concomitant biomarker modulation indicative of CHK1 inhibition. CCT244747 also showed marked antitumor activity as a single agent in a MYCN-driven neuroblastoma. Conclusion CCT244747 represents the first structural disclosure of a highly selective, orally active CHK1 inhibitor and warrants further evaluation alone or combined with genotoxic anticancer therapies. PMID:22929806

  4. Repeated Course Enrollments.

    ERIC Educational Resources Information Center

    Windham, Patricia

    This report resents tables of repeated course enrollment data in Florida community colleges for the fall 1993 cohort. Overall, the percent of repeats in college preparatory courses was greater than that of college credit courses. Within ICS codes, the highest percentage of credit repeat enrollments was in mathematics; the second highest was in…

  5. Programmed Cell Death Protein 5 Interacts with the Cytosolic Chaperonin Containing Tailless Complex Polypeptide 1 (CCT) to Regulate β-Tubulin Folding* ♦

    PubMed Central

    Tracy, Christopher M.; Gray, Amy J.; Cuéllar, Jorge; Shaw, Tanner S.; Howlett, Alyson C.; Taylor, Ryan M.; Prince, John T.; Ahn, Natalie G.; Valpuesta, José M.; Willardson, Barry M.

    2014-01-01

    Programmed cell death protein 5 (PDCD5) has been proposed to act as a pro-apoptotic factor and tumor suppressor. However, the mechanisms underlying its apoptotic function are largely unknown. A proteomics search for binding partners of phosducin-like protein, a co-chaperone for the cytosolic chaperonin containing tailless complex polypeptide 1 (CCT), revealed a robust interaction between PDCD5 and CCT. PDCD5 formed a complex with CCT and β-tubulin, a key CCT-folding substrate, and specifically inhibited β-tubulin folding. Cryo-electron microscopy studies of the PDCD5·CCT complex suggested a possible mechanism of inhibition of β-tubulin folding. PDCD5 bound the apical domain of the CCTβ subunit, projecting above the folding cavity without entering it. Like PDCD5, β-tubulin also interacts with the CCTβ apical domain, but a second site is found at the sensor loop deep within the folding cavity. These orientations of PDCD5 and β-tubulin suggest that PDCD5 sterically interferes with β-tubulin binding to the CCTβ apical domain and inhibits β-tubulin folding. Given the importance of tubulins in cell division and proliferation, PDCD5 might exert its apoptotic function at least in part through inhibition of β-tubulin folding. PMID:24375412

  6. Complete cDNA and deduced amino acid sequence of the chaperonin containing T-complex polypeptide 1 (CCT) delta subunit from Aedes triseriatus mosquitoes.

    PubMed

    Blitvich, B J; Rayms-Keller, A; Blair, C D; Beaty, B J

    2001-01-01

    The chaperonin containing t-complex polypeptide 1 (CCT) assists in the ATP-dependent folding and assembly of newly translated actin and tubulin in the eukaryotic cytosol. CCT is composed of eight different subunits, each encoded by an independent gene. In this report, we used RT-PCR amplification and 5'- and 3'-rapid amplification of cDNA ends (RACE) to determine the complete cDNA sequence of the CCT delta subunit from Aedes triseriatus mosquitoes. The CCT delta cDNA is 1936 nucleotides in length and encodes a putative 533 amino acid protein with a calculated molecular mass of 57,179 daltons and pI of 7.15. Hydrophobic residues comprise 39.8% of the amino acid sequence and putative motifs for ATP-binding and ATPase-activity are present. The amino acid sequence displays strong sequence similarity to Drosophila melanogaster (92%), human (85%), puffer fish (84%) and mouse (84%) counterparts. CCT delta mRNA was detected in both biosynthetically active (embryonating) and dormant (diapausing) Ae. triseriatus embryos by RT-PCR analysis. PMID:11762197

  7. The S-Domain Receptor Kinase Arabidopsis Receptor Kinase2 and the U Box/Armadillo Repeat-Containing E3 Ubiquitin Ligase9 Module Mediates Lateral Root Development under Phosphate Starvation in Arabidopsis1[C][W][OPEN

    PubMed Central

    Deb, Srijani; Sankaranarayanan, Subramanian; Wewala, Gayathri; Widdup, Ellen; Samuel, Marcus A.

    2014-01-01

    When plants encounter nutrient-limiting conditions in the soil, the root architecture is redesigned to generate numerous lateral roots (LRs) that increase the surface area of roots, promoting efficient uptake of these deficient nutrients. Of the many essential nutrients, reduced availability of inorganic phosphate has a major impact on plant growth because of the requirement of inorganic phosphate for synthesis of organic molecules, such as nucleic acids, ATP, and phospholipids, that function in various crucial metabolic activities. In our screens to identify a potential role for the S-domain receptor kinase1-6 and its interacting downstream signaling partner, the Arabidopsis (Arabidopsis thaliana) plant U box/armadillo repeat-containing E3 ligase9 (AtPUB9), we identified a role for this module in regulating LR development under phosphate-starved conditions. Our results show that Arabidopsis double mutant plants lacking AtPUB9 and Arabidopsis Receptor Kinase2 (AtARK2; ark2-1/pub9-1) display severely reduced LRs when grown under phosphate-starved conditions. Under these starvation conditions, these plants accumulated very low to no auxin in their primary root and LR tips as observed through expression of the auxin reporter DR5::uidA transgene. Exogenous auxin was sufficient to rescue the LR developmental defects in the ark2-1/pub9-1 lines, indicating a requirement of auxin accumulation for this process. Our subcellular localization studies with tobacco (Nicotiana tabacum) suspension-cultured cells indicate that interaction between ARK2 and AtPUB9 results in accumulation of AtPUB9 in the autophagosomes. Inhibition of autophagy in wild-type plants resulted in reduction of LR development and auxin accumulation under phosphate-starved conditions, suggesting a role for autophagy in regulating LR development. Thus, our study has uncovered a previously unknown signaling module (ARK2-PUB9) that is required for auxin-mediated LR development under phosphate-starved conditions

  8. N-terminal domain-mediated homodimerization is required for photoreceptor activity of Arabidopsis CRYPTOCHROME 1.

    PubMed

    Sang, Yi; Li, Qing-Hua; Rubio, Vicente; Zhang, Yan-Chun; Mao, Jian; Deng, Xing-Wang; Yang, Hong-Quan

    2005-05-01

    Cryptochromes (CRY) are blue light receptors that share sequence similarity with photolyases, flavoproteins that catalyze the repair of UV light-damaged DNA. Transgenic Arabidopsis thaliana seedlings expressing the C-terminal domains of the Arabidopsis CRY fused to beta-glucuronidase (GUS) display a constitutive photomorphogenic (COP) phenotype, indicating that the signaling mechanism of Arabidopsis CRY is mediated through the C-terminal domain. The role of the Arabidopsis CRY N-terminal photolyase-like domain in CRY action remains poorly understood. Here, we report the essential role of the Arabidopsis CRY1 N-terminal domain (CNT1) in the light activation of CRY1 photoreceptor activity. Yeast two-hybrid assay, in vitro binding, in vivo chemical cross-linking, gel filtration, and coimmunoprecipitation studies indicate that CRY1 homodimerizes in a light-independent manner. Mutagenesis and transgenic studies demonstrate that CNT1-mediated dimerization is required for light activation of the C-terminal domain of CRY1 (CCT1). Transgenic data and native gel electrophoresis studies suggest that multimerization of GUS is both responsible and required for mediating a COP phenotype on fusion to CCT1. These results indicate that the properties of the GUS multimer are analogous to those of the light-modified CNT1 dimer. Irradiation with blue light modifies the properties of the CNT1 dimer, resulting in a change in CCT1, activating CCT1, and eventually triggering the CRY1 signaling pathway. PMID:15805487

  9. Confounding dynamic risk taking propensity with a momentum prognostic strategy: the case of the Columbia Card Task (CCT)

    PubMed Central

    Markiewicz, Łukasz; Kubińska, Elżbieta; Tyszka, Tadeusz

    2015-01-01

    Figner et al. (2009) developed the Columbia Card Task (CCT) to measure risk-taking attitudes. This tool consists of two versions: in the COLD version the decision maker needs to state in advance how many cards (out of 32) they want to turn over (so called static risk taking), in the HOT version they have the possibility of turning over all 32 cards one-by-one until they decide to finish (dynamic risk taking). We argue that the HOT version confounds an individual’s willingness to accept risk with their beliefs in trend continuation vs. trend reversal in a prognostic task. In two experimental studies we show that people believing in trend continuation (momentum subjects) turn over more cards than those believing in trend reversal (contrarians) in the HOT version of the task. However, this is not the case in the COLD version. Thus, we provide evidence that, when considered as a dynamic risk propensity measure, the number of turned over cards in the HOT version of the CCT is a contaminated measure and reflects two phenomena: (1) risk preference and (2) the decision-maker’s belief in trend continuation. We speculate that other dynamic risk taking measures can also be biased by a momentum strategy. PMID:26300799

  10. CCT- and CRI-tuning of white light-emitting diodes using three-dimensional non-close-packed colloidal photonic crystals with photonic stop-bands.

    PubMed

    Lai, Chun-Feng; Chang, Chung-Chieh; Wang, Ming-Jye; Wu, Mau-Kuen

    2013-07-01

    This study exhibited the correlated color temperature (CCT)- and color-rendering index (CRI)-tuning behavior of light emission from white light-emitting diodes (WLEDs) using three-dimensional non-close-packed (3D NCP) colloidal photonic crystals (CPhCs). The CCT of approximately 5300 K (characteristic of cold WLEDs) of white light propagated through the NCP CPhCs dropped to 3000 K (characteristic of warm WLEDs) because of the photonic stop-bands based on the photonic band structures of NCP CPhCs. This study successfully developed a novel technique that introduces lower-cost CCT- and CRI-tuning cold WLEDs with a CRI of over 90 that of warm WLEDs by using 3D NCP CPhCs. PMID:24104495

  11. DNA Triplet Repeat Expansion and Mismatch Repair

    PubMed Central

    Iyer, Ravi R.; Pluciennik, Anna; Napierala, Marek; Wells, Robert D.

    2016-01-01

    DNA mismatch repair is a conserved antimutagenic pathway that maintains genomic stability through rectification of DNA replication errors and attenuation of chromosomal rearrangements. Paradoxically, mutagenic action of mismatch repair has been implicated as a cause of triplet repeat expansions that cause neurological diseases such as Huntington disease and myotonic dystrophy. This mutagenic process requires the mismatch recognition factor MutSβ and the MutLα (and/or possibly MutLγ) endonuclease, and is thought to be triggered by the transient formation of unusual DNA structures within the expanded triplet repeat element. This review summarizes the current knowledge of DNA mismatch repair involvement in triplet repeat expansion, which encompasses in vitro biochemical findings, cellular studies, and various in vivo transgenic animal model experiments. We present current mechanistic hypotheses regarding mismatch repair protein function in mediating triplet repeat expansions and discuss potential therapeutic approaches targeting the mismatch repair pathway. PMID:25580529

  12. Reconfigurable multiport EPON repeater

    NASA Astrophysics Data System (ADS)

    Oishi, Masayuki; Inohara, Ryo; Agata, Akira; Horiuchi, Yukio

    2009-11-01

    An extended reach EPON repeater is one of the solutions to effectively expand FTTH service areas. In this paper, we propose a reconfigurable multi-port EPON repeater for effective accommodation of multiple ODNs with a single OLT line card. The proposed repeater, which has multi-ports in both OLT and ODN sides, consists of TRs, BTRs with the CDR function and a reconfigurable electrical matrix switch, can accommodate multiple ODNs to a single OLT line card by controlling the connection of the matrix switch. Although conventional EPON repeaters require full OLT line cards to accommodate subscribers from the initial installation stage, the proposed repeater can dramatically reduce the number of required line cards especially when the number of subscribers is less than a half of the maximum registerable users per OLT. Numerical calculation results show that the extended reach EPON system with the proposed EPON repeater can save 17.5% of the initial installation cost compared with a conventional repeater, and can be less expensive than conventional systems up to the maximum subscribers especially when the percentage of ODNs in lightly-populated areas is higher.

  13. Revisiting the TALE repeat.

    PubMed

    Deng, Dong; Yan, Chuangye; Wu, Jianping; Pan, Xiaojing; Yan, Nieng

    2014-04-01

    Transcription activator-like (TAL) effectors specifically bind to double stranded (ds) DNA through a central domain of tandem repeats. Each TAL effector (TALE) repeat comprises 33-35 amino acids and recognizes one specific DNA base through a highly variable residue at a fixed position in the repeat. Structural studies have revealed the molecular basis of DNA recognition by TALE repeats. Examination of the overall structure reveals that the basic building block of TALE protein, namely a helical hairpin, is one-helix shifted from the previously defined TALE motif. Here we wish to suggest a structure-based re-demarcation of the TALE repeat which starts with the residues that bind to the DNA backbone phosphate and concludes with the base-recognition hyper-variable residue. This new numbering system is consistent with the α-solenoid superfamily to which TALE belongs, and reflects the structural integrity of TAL effectors. In addition, it confers integral number of TALE repeats that matches the number of bound DNA bases. We then present fifteen crystal structures of engineered dHax3 variants in complex with target DNA molecules, which elucidate the structural basis for the recognition of bases adenine (A) and guanine (G) by reported or uncharacterized TALE codes. Finally, we analyzed the sequence-structure correlation of the amino acid residues within a TALE repeat. The structural analyses reported here may advance the mechanistic understanding of TALE proteins and facilitate the design of TALEN with improved affinity and specificity. PMID:24622844

  14. Quantum repeated games revisited

    NASA Astrophysics Data System (ADS)

    Frąckiewicz, Piotr

    2012-03-01

    We present a scheme for playing quantum repeated 2 × 2 games based on Marinatto and Weber’s approach to quantum games. As a potential application, we study the twice repeated Prisoner’s Dilemma game. We show that results not available in the classical game can be obtained when the game is played in the quantum way. Before we present our idea, we comment on the previous scheme of playing quantum repeated games proposed by Iqbal and Toor. We point out the drawbacks that make their results unacceptable.

  15. U-box protein carboxyl terminus of Hsc70-interacting protein (CHIP) mediates poly-ubiquitylation preferentially on four-repeat Tau and is involved in neurodegeneration of tauopathy.

    PubMed

    Hatakeyama, Shigetsugu; Matsumoto, Masaki; Kamura, Takumi; Murayama, Miyuki; Chui, Du-Hua; Planel, Emmanuel; Takahashi, Ryosuke; Nakayama, Keiichi I; Takashima, Akihiko

    2004-10-01

    Neurofibrillary tangles (NFTs), which are composed of hyperphosphorylated and ubiquitylated tau, are exhibited at regions where neuronal loss occurs in neurodegenerative diseases; however, the mechanisms of NFT formation remain unknown. Molecular studies of frontotemporal dementia with parkinsonism-17 demonstrated that increasing the ratio of tau with exon 10 insertion induced fibrillar tau accumulation. Here, we show that carboxyl terminus of Hsc70-interacting protein (CHIP), a U-box protein, recognizes the microtubule-binding repeat region of tau and preferentially ubiquitylates four-repeat tau compared with three-repeat tau. Overexpression of CHIP induced the prompt degradation of tau, reduced the formation of detergent-insoluble tau and inhibited proteasome inhibitor-induced cell death. NFT bearing neurons in progressive supranuclear palsy, in which four-repeat tau is a component, showed the accumulation of CHIP. Thus, CHIP is a ubiquitin ligase for four-repeat tau and maintains neuronal survival by regulating the quality control of tau in neurons. PMID:15447663

  16. Archive of digital Chirp subbottom profile data collected during USGS cruise 08CCT01, Mississippi Gulf Islands, July 2008

    USGS Publications Warehouse

    Forde, Arnell S.; Dadisman, Shawn V.; Flocks, James G.; Worley, Charles R.

    2011-01-01

    In July of 2008, the U.S. Geological Survey (USGS) conducted geophysical surveys to investigate the geologic controls on island framework from Ship Island to Horn Island, Mississippi, for the Northern Gulf of Mexico (NGOM) Ecosystem Change and Hazard Susceptibility project. Funding was provided through the Geologic Framework and Holocene Coastal Evolution of the Mississippi-Alabama Region Subtask (http://ngom.er.usgs.gov/task2_2/index.php); this project is also part of a broader USGS study on Coastal Change and Transport (CCT). This report serves as an archive of unprocessed digital Chirp seismic reflection data, trackline maps, navigation files, Geographic Information System (GIS) files, Field Activity Collection System (FACS) logs, observer's logbook, and formal Federal Geographic Data Committee (FGDC) metadata. Gained (a relative increase in signal amplitude) digital images of the seismic profiles are also provided. Refer to the Acronyms page for expansion of acronyms and abbreviations used in this report.

  17. Simple sequence repeats in Haemophilus influenzae.

    PubMed

    Power, Peter M; Sweetman, W A; Gallacher, N J; Woodhall, M R; Kumar, G A; Moxon, E R; Hood, D W

    2009-03-01

    Simple sequence repeat (SSRs) of DNA are subject to high rates of mutation and are important mediators of adaptation in Haemophilus influenzae. Previous studies of the Rd KW20 genome identified the primacy of tetranucleotide SSRs in mediating phase variation (the rapid reversible switching of gene expression) of surface exposed structures such as lipopolysaccharide. The recent sequencing of the genomes of multiple strains of H. influenzae allowed the comparison of the SSRs (repeat units of one to nine nucleotides in length) in detail across four complete H. influenzae genomes and then comparison with a further 12 genomes when they became available. The SSR loci were broadly classified into three groups: (1) those that did not vary; (2) those for which some variation between strains was observed but this could not be linked to variation of gene expression; and (3) those that both varied and were located in regions consistent with mediating phase variable gene expression. Comparative analysis of 988 SSR associated loci confirmed that tetranucleotide repeats were the major mediators of phase variation and extended the repertoire of known tetranucleotide SSR loci by identifying ten previously uncharacterised tetranucleotide SSR loci with the potential to mediate phase variation which were unequally distributed across the H. influenzae pan-genome. Further, analysis of non-tetranucleotide SSR in the 16 strains revealed a number of mononucleotide, dinucleotide, pentanucleotide, heptanucleotide, and octanucleotide SSRs which were consistent with these tracts mediating phase variation. This study substantiates previous findings as to the important role that tetranucleotide SSRs play in H. influenzae biology. Two Brazilian isolates showed the most variation in their complement of SSRs suggesting the possibility of geographic and phenotypic influences on SSR distribution. PMID:19095084

  18. The Pentapeptide Repeat Proteins

    SciTech Connect

    Vetting,M.; Hegde, S.; Fajardo, J.; Fiser, A.; Roderick, S.; Takiff, H.; Blanchard, J.

    2006-01-01

    The Pentapeptide Repeat Protein (PRP) family has over 500 members in the prokaryotic and eukaryotic kingdoms. These proteins are composed of, or contain domains composed of, tandemly repeated amino acid sequences with a consensus sequence of [S, T,A, V][D, N][L, F]-[S, T,R][G]. The biochemical function of the vast majority of PRP family members is unknown. The three-dimensional structure of the first member of the PRP family was determined for the fluoroquinolone resistance protein (MfpA) from Mycobacterium tuberculosis. The structure revealed that the pentapeptide repeats encode the folding of a novel right-handed quadrilateral {beta}-helix. MfpA binds to DNA gyrase and inhibits its activity. The rod-shaped, dimeric protein exhibits remarkable size, shape and electrostatic similarity to DNA.

  19. Characterization of DNA sequences that mediate nuclear protein binding to the regulatory region of the Pisum sativum (pea) chlorophyl a/b binding protein gene AB80: identification of a repeated heptamer motif.

    PubMed

    Argüello, G; García-Hernández, E; Sánchez, M; Gariglio, P; Herrera-Estrella, L; Simpson, J

    1992-05-01

    Two protein factors binding to the regulatory region of the pea chlorophyl a/b binding protein gene AB80 have been identified. One of these factors is found only in green tissue but not in etiolated or root tissue. The second factor (denominated ABF-2) binds to a DNA sequence element that contains a direct heptamer repeat TCTCAAA. It was found that presence of both of the repeats is essential for binding. ABF-2 is present in both green and etiolated tissue and in roots and factors analogous to ABF-2 are present in several plant species. Computer analysis showed that the TCTCAAA motif is present in the regulatory region of several plant genes. PMID:1303797

  20. Honesty through repeated interactions.

    PubMed

    Rich, Patricia; Zollman, Kevin J S

    2016-04-21

    In the study of signaling, it is well known that the cost of deception is an essential element for stable honest signaling in nature. In this paper, we show how costs for deception can arise endogenously from repeated interactions between individuals. Utilizing the Sir Philip Sidney game as an illustrative case, we show that repeated interactions can sustain honesty with no observable signal costs, even when deception cannot be directly observed. We provide a number of potential experimental tests for this theory which distinguish it from the available alternatives. PMID:26869213

  1. Analysis of the subgroup A avian sarcoma and leukosis virus receptor: the 40-residue, cysteine-rich, low-density lipoprotein receptor repeat motif of Tva is sufficient to mediate viral entry.

    PubMed

    Rong, L; Bates, P

    1995-08-01

    The genes encoding the receptor for subgroup A Rous sarcoma viruses (tva) were recently cloned from both chicken and quail cells (P. Bates, J. A. T. Young, and H. E. Varmus, Cell 74:1043-1051, 1993; J. A. T. Young, P. Bates, and H. E. Varmus, J. Virol. 67:1811-1816, 1993). Previous work suggested that only the extracellular domain of Tva interacts with the virus (P. Bates, J. A. T. Young, and H. E. Varmus, Cell 74:1043-1051, 1993). Tva is a small membrane-associated protein containing in its extracellular domain a 40-amino-acid region which is closely related to the low-density lipoprotein receptor (LDLR) repeat motif. To determine the region of the Tva extracellular domain responsible for viral receptor function, we created chimeric proteins containing various regions of the Tva extracellular domain fused with a murine CD8 membrane anchor. Analysis of these proteins demonstrates that any chimera containing the Tva LDLR repeat motif can specifically bind the envelope protein of subgroup A avian sarcoma and leukosis viruses. Furthermore, NIH 3T3 cell lines expressing these chimeric proteins were efficiently infected by subgroup A avian sarcoma and leukosis virus vectors. Our results demonstrate that the 40-residue-long LDLR repeat motif of Tva is responsible for viral receptor function. PMID:7609052

  2. Bidirectional Manchester repeater

    NASA Technical Reports Server (NTRS)

    Ferguson, J.

    1980-01-01

    Bidirectional Manchester repeater is inserted at periodic intervals along single bidirectional twisted pair transmission line to detect, amplify, and transmit bidirectional Manchester 11 code signals. Requiring only 18 TTL 7400 series IC's, some line receivers and drivers, and handful of passive components, circuit is simple and relatively inexpensive to build.

  3. Triggering of repeated earthquakes

    NASA Astrophysics Data System (ADS)

    Sobolev, G. A.; Zakrzhevskaya, N. A.; Sobolev, D. G.

    2016-03-01

    Based on the analysis of the world's earthquakes with magnitudes M ≥ 6.5 for 1960-2013, it is shown that they cause global-scale coherent seismic oscillations which most distinctly manifest themselves in the period interval of 4-6 min during 1-3 days after the event. After these earthquakes, a repeated shock has an increased probability to occur in different seismically active regions located as far away as a few thousand km from the previous event, i.e., a remote interaction of seismic events takes place. The number of the repeated shocks N( t) decreases with time, which characterizes the memory of the lithosphere about the impact that has occurred. The time decay N( t) can be approximated by the linear, exponential, and powerlaw dependences. No distinct correlation between the spatial locations of the initial and repeated earthquakes is revealed. The probable triggering mechanisms of the remote interaction between the earthquakes are discussed. Surface seismic waves traveling several times around the Earth's, coherent oscillations, and global source are the most preferable candidates. This may lead to the accumulation and coalescence of ruptures in the highly stressed or weakened domains of a seismically active region, which increases the probability of a repeated earthquake.

  4. Repeated Causal Decision Making

    ERIC Educational Resources Information Center

    Hagmayer, York; Meder, Bjorn

    2013-01-01

    Many of our decisions refer to actions that have a causal impact on the external environment. Such actions may not only allow for the mere learning of expected values or utilities but also for acquiring knowledge about the causal structure of our world. We used a repeated decision-making paradigm to examine what kind of knowledge people acquire in…

  5. Accumulate repeat accumulate codes

    NASA Technical Reports Server (NTRS)

    Abbasfar, Aliazam; Divsalar, Dariush; Yao, Kung

    2004-01-01

    In this paper we propose an innovative channel coding scheme called 'Accumulate Repeat Accumulate codes' (ARA). This class of codes can be viewed as serial turbo-like codes, or as a subclass of Low Density Parity Check (LDPC) codes, thus belief propagation can be used for iterative decoding of ARA codes on a graph. The structure of encoder for this class can be viewed as precoded Repeat Accumulate (RA) code or as precoded Irregular Repeat Accumulate (IRA) code, where simply an accumulator is chosen as a precoder. Thus ARA codes have simple, and very fast encoder structure when they representing LDPC codes. Based on density evolution for LDPC codes through some examples for ARA codes, we show that for maximum variable node degree 5 a minimum bit SNR as low as 0.08 dB from channel capacity for rate 1/2 can be achieved as the block size goes to infinity. Thus based on fixed low maximum variable node degree, its threshold outperforms not only the RA and IRA codes but also the best known LDPC codes with the dame maximum node degree. Furthermore by puncturing the accumulators any desired high rate codes close to code rate 1 can be obtained with thresholds that stay close to the channel capacity thresholds uniformly. Iterative decoding simulation results are provided. The ARA codes also have projected graph or protograph representation that allows for high speed decoder implementation.

  6. Duct Leakage Repeatability Testing

    SciTech Connect

    Walker, Iain; Sherman, Max

    2014-01-01

    Duct leakage often needs to be measured to demonstrate compliance with requirements or to determine energy or Indoor Air Quality (IAQ) impacts. Testing is often done using standards such as ASTM E1554 (ASTM 2013) or California Title 24 (California Energy Commission 2013 & 2013b), but there are several choices of methods available within the accepted standards. Determining which method to use or not use requires an evaluation of those methods in the context of the particular needs. Three factors that are important considerations are the cost of the measurement, the accuracy of the measurement and the repeatability of the measurement. The purpose of this report is to evaluate the repeatability of the three most significant measurement techniques using data from the literature and recently obtained field data. We will also briefly discuss the first two factors. The main question to be answered by this study is to determine if differences in the repeatability of these tests methods is sufficient to indicate that any of these methods is so poor that it should be excluded from consideration as an allowed procedure in codes and standards.

  7. A Gradient of ATP Affinities Generates an Asymmetric Power Stroke Driving the Chaperonin TRIC/CCT Folding Cycle

    PubMed Central

    Reissmann, Stefanie; Joachimiak, Lukasz A.; Chen, Bryan; Meyer, Anne S.; Nguyen, Anthony; Frydman, Judith

    2012-01-01

    SUMMARY The eukaryotic chaperonin TRiC/CCT uses ATP cycling to fold many essential proteins that other chaperones cannot fold. This 1 MDa hetero-oligomer consists of two identical stacked rings assembled from eight paralogous subunits, each containing a conserved ATP-binding domain. Here, we report a dramatic asymmetry in the ATP utilization cycle of this ring-shaped chaperonin, despite its apparently symmetric architecture. Only four of the eight different subunits bind ATP at physiological concentrations. ATP binding and hydrolysis by the low-affinity subunits is fully dispensable for TRiC function in vivo. The conserved nucleotide-binding hierarchy among TRiC subunits is evolutionarily modulated through differential nucleoside contacts. Strikingly, high-and low-affinity subunits are spatially segregated within two contiguous hemispheres in the ring, generating an asymmetric power stroke that drives the folding cycle. This unusual mode of ATP utilization likely serves to orchestrate a directional mechanism underlying TRiC/CCT’s unique ability to fold complex eukaryotic proteins. PMID:23041314

  8. Effect of Niobium on the Ferrite Continuous-Cooling-Transformation (CCT) Curve of Ultrahigh-Thickness Cr-Mo Steel

    NASA Astrophysics Data System (ADS)

    Lee, Sanghoon; Na, Hyesung; Kim, Byunghoon; Kim, Dongjin; Kang, Chungyun

    2013-06-01

    Pressure vessels made for petrochemical and power plants using Cr-Mo steel must be thick (≥400 mm) and have high tensile strength (≥600 MPa). However, the tensile strength in the middle portion of the vessel is very low as a result of ferrite formation. Therefore, research was performed to study the ferrite transformation that occurs in the middle portion of high-thickness Cr-Mo steel when Nb is added to it. The ferrite-formation start time of the continuous-cooling-transformation (CCT) curve decreased with an increase in Nb content until the latter reached 0.05 pct. On cooling from the austenitizing temperature, some of the NbC present at the austenitizing temperature of 1203 K (930 °C) goes into austenite solution in the temperature range of 1173 K to 1073 K (900 °C to 800 °C). However, the ferrite curve shifted to the left for the alloy containing 0.075 pct Nb. It is postulated that the surplus NbC could act as ferrite nucleation sites despite the lower cooling rate. As a result, the hardenability improved in the order of the following Nb content: 0.05 pct, 0.025 pct, 0 pct, and 0.075 pct.

  9. Final report on CCT-K2.5: NRC/NMIJ/INRIM comparison of capsule-type standard platinum resistance thermometers from 13.8 K to 273.16 K

    NASA Astrophysics Data System (ADS)

    Hill, K. D.; Nakano, T.; Steur, P.

    2015-01-01

    A comparison of capsule-type standard platinum resistance thermometers (CSPRT) was carried out between NRC (Canada), NMIJ (Japan), and INRIM (Italy) over the temperature range 13.8 K to 273.16 K. The principal goal was to link the NMIJ realization of the International Temperature Scale of 1990 to the results of the Consultative Committee for Thermometry Key Comparison CCT-K2 over this temperature range. Additionally, in the intervening years since the CCT-K2 measurements were carried out, INRIM has improved the Italian national standards in the temperature range of the comparison, and was interested in the opportunity to update that assessment. The comparison has revealed the calibrations at NMIJ to be in agreement with the KCRV of CCT-K2 within the expanded uncertainty for all temperatures of the comparison. The linkage to the CCT-K2 data supports the inclusion of the NMIJ CMCs in Appendix C of the KCDB. The INRIM data are also consistent with the KCRV of CCT-K2 within the expanded uncertainty of the comparison. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCT, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  10. C9orf72 repeat expansions cause neurodegeneration in Drosophila through arginine-rich proteins

    PubMed Central

    Ridler, Charlotte E.; Clayton, Emma L.; Devoy, Anny; Moens, Thomas; Norona, Frances E.; Woollacott, Ione O.C.; Pietrzyk, Julian; Cleverley, Karen; Nicoll, Andrew J.; Pickering-Brown, Stuart; Dols, Jacqueline; Cabecinha, Melissa; Hendrich, Oliver; Fratta, Pietro; Fisher, Elizabeth M.C.; Partridge, Linda; Isaacs, Adrian M.

    2016-01-01

    An expanded GGGGCC repeat in C9orf72 is the most common genetic cause of frontotemporal dementia and amyotrophic lateral sclerosis. A fundamental question is whether toxicity is driven by the repeat RNA itself and/or by dipeptide repeat proteins generated by repeat-associated, non-ATG translation. To address this question we developed in vitro and in vivo models to dissect repeat RNA and dipeptide repeat protein toxicity. Expression of pure repeats in Drosophila caused adult-onset neurodegeneration attributable to poly-(glycine-arginine) proteins. Thus expanded repeats promoted neurodegeneration through neurotoxic proteins. Expression of individual dipeptide repeat proteins with a non-GGGGCC RNA sequence showed both poly-(glycine-arginine) and poly-(proline-arginine) proteins caused neurodegeneration. These findings are consistent with a dual toxicity mechanism, whereby both arginine-rich proteins and repeat RNA contribute to C9orf72-mediated neurodegeneration. PMID:25103406

  11. Duct Leakage Repeatability Testing

    SciTech Connect

    Walker, Iain; Sherman, Max

    2014-08-01

    The purpose of this report is to evaluate the repeatability of the three most significant measurement techniques for duct leakage using data from the literature and recently obtained field data. We will also briefly discuss the first two factors. The main question to be answered by this study is to determine if differences in the repeatability of these tests methods is sufficient to indicate that any of these methods is so poor that it should be excluded from consideration as an allowed procedure in codes and standards. The three duct leak measurement methods assessed in this report are the two duct pressurization methods that are commonly used by many practitioners and the DeltaQ technique. These are methods B, C and A, respectively of the ASTM E1554 standard. Although it would be useful to evaluate other duct leak test methods, this study focused on those test methods that are commonly used and are required in various test standards, such as BPI (2010), RESNET (2014), ASHRAE 62.2 (2013), California Title 24 (CEC 2012), DOE Weatherization and many other energy efficiency programs.

  12. Repeated measures with zeros.

    PubMed

    Berk, K N; Lachenbruch, P A

    2002-08-01

    Consider repeated measures data with many zeros. For the case with one grouping factor and one repeated measure, we examine several models, assuming that the nonzero data are roughly lognormal. One of the simplest approaches is to model the zeros as left-censored observations from the lognormal distribution. A random effect is assumed for subjects. The censored model makes a strong assumption about the relationship between the zeros and the nonzero values. To check on this, you can instead assume that some of the zeros are 'true' zeros and model them as Bernoulli. Then the other values are modeled with a censored lognormal. A logistic model is used for the Bernoulli p, the probability of a true nonzero. The fit of the pure left-censored lognormal can be assessed by testing the hypothesis that p is 1, as described by Moulton and Halsey. The model can also be simplified by omitting the censoring, leaving a logistic model for the zeros and a lognormal model for the nonzero values. This is approximately equivalent to modeling the zero and nonzero values separately, a two-part model. In contrast to the censored model, this model assumes only a slight relationship (a covariance component) between the occurrence of zeros and the size of the nonzero values. The models are compared in terms of an example with data from children's private speech. PMID:12197298

  13. The rapamycin sensitivity of human T-cell leukaemia virus type I-induced T-cell proliferation is mediated independently of the polypyrimidine motifs in the 5' long terminal repeat.

    PubMed

    Rose, N; Lever, A

    2001-02-01

    The immunosuppressant rapamycin can regulate the translation of a subset of messenger RNAs, a phenotype which has been linked to the presence of a polypyrimidine motif [C(N)(4-14)] downstream of the mRNA cap structure. T-cell clones naturally infected with transcriptionally active human T-cell leukaemia virus, type I (HTLV-I) undergo autologous proliferation; this phenotype is inhibited by rapamycin but not FK506, which reverses the rapamycin effect. Within the R region of the HTLV-I 5' long terminal repeat (LTR) there are seven polypyrimidine motifs. We sought to determine if these were involved in the sensitivity of proliferation to the presence of rapamycin. Here we illustrate the generation of an in vitro model of this rapamycin-sensitivity and the analysis of LTR mutants which were created to determine the importance of the polypyrimidine motifs. Reporter gene assays suggest the effect is independent of the polypyrimidine motifs in the virus leader sequence. PMID:11161283

  14. Repeat Customer Success in Extension

    ERIC Educational Resources Information Center

    Bess, Melissa M.; Traub, Sarah M.

    2013-01-01

    Four multi-session research-based programs were offered by two Extension specialist in one rural Missouri county. Eleven participants who came to multiple Extension programs could be called "repeat customers." Based on the total number of participants for all four programs, 25% could be deemed as repeat customers. Repeat customers had…

  15. RepeatsDB: a database of tandem repeat protein structures

    PubMed Central

    Di Domenico, Tomás; Potenza, Emilio; Walsh, Ian; Gonzalo Parra, R.; Giollo, Manuel; Minervini, Giovanni; Piovesan, Damiano; Ihsan, Awais; Ferrari, Carlo; Kajava, Andrey V.; Tosatto, Silvio C.E.

    2014-01-01

    RepeatsDB (http://repeatsdb.bio.unipd.it/) is a database of annotated tandem repeat protein structures. Tandem repeats pose a difficult problem for the analysis of protein structures, as the underlying sequence can be highly degenerate. Several repeat types haven been studied over the years, but their annotation was done in a case-by-case basis, thus making large-scale analysis difficult. We developed RepeatsDB to fill this gap. Using state-of-the-art repeat detection methods and manual curation, we systematically annotated the Protein Data Bank, predicting 10 745 repeat structures. In all, 2797 structures were classified according to a recently proposed classification schema, which was expanded to accommodate new findings. In addition, detailed annotations were performed in a subset of 321 proteins. These annotations feature information on start and end positions for the repeat regions and units. RepeatsDB is an ongoing effort to systematically classify and annotate structural protein repeats in a consistent way. It provides users with the possibility to access and download high-quality datasets either interactively or programmatically through web services. PMID:24311564

  16. Environmental stress induces trinucleotide repeat mutagenesis in human cells.

    PubMed

    Chatterjee, Nimrat; Lin, Yunfu; Santillan, Beatriz A; Yotnda, Patricia; Wilson, John H

    2015-03-24

    The dynamic mutability of microsatellite repeats is implicated in the modification of gene function and disease phenotype. Studies of the enhanced instability of long trinucleotide repeats (TNRs)-the cause of multiple human diseases-have revealed a remarkable complexity of mutagenic mechanisms. Here, we show that cold, heat, hypoxic, and oxidative stresses induce mutagenesis of a long CAG repeat tract in human cells. We show that stress-response factors mediate the stress-induced mutagenesis (SIM) of CAG repeats. We show further that SIM of CAG repeats does not involve mismatch repair, nucleotide excision repair, or transcription, processes that are known to promote TNR mutagenesis in other pathways of instability. Instead, we find that these stresses stimulate DNA rereplication, increasing the proportion of cells with >4 C-value (C) DNA content. Knockdown of the replication origin-licensing factor CDT1 eliminates both stress-induced rereplication and CAG repeat mutagenesis. In addition, direct induction of rereplication in the absence of stress also increases the proportion of cells with >4C DNA content and promotes repeat mutagenesis. Thus, environmental stress triggers a unique pathway for TNR mutagenesis that likely is mediated by DNA rereplication. This pathway may impact normal cells as they encounter stresses in their environment or during development or abnormal cells as they evolve metastatic potential. PMID:25775519

  17. Environmental stress induces trinucleotide repeat mutagenesis in human cells

    PubMed Central

    Chatterjee, Nimrat; Lin, Yunfu; Santillan, Beatriz A.; Yotnda, Patricia; Wilson, John H.

    2015-01-01

    The dynamic mutability of microsatellite repeats is implicated in the modification of gene function and disease phenotype. Studies of the enhanced instability of long trinucleotide repeats (TNRs)—the cause of multiple human diseases—have revealed a remarkable complexity of mutagenic mechanisms. Here, we show that cold, heat, hypoxic, and oxidative stresses induce mutagenesis of a long CAG repeat tract in human cells. We show that stress-response factors mediate the stress-induced mutagenesis (SIM) of CAG repeats. We show further that SIM of CAG repeats does not involve mismatch repair, nucleotide excision repair, or transcription, processes that are known to promote TNR mutagenesis in other pathways of instability. Instead, we find that these stresses stimulate DNA rereplication, increasing the proportion of cells with >4 C-value (C) DNA content. Knockdown of the replication origin-licensing factor CDT1 eliminates both stress-induced rereplication and CAG repeat mutagenesis. In addition, direct induction of rereplication in the absence of stress also increases the proportion of cells with >4C DNA content and promotes repeat mutagenesis. Thus, environmental stress triggers a unique pathway for TNR mutagenesis that likely is mediated by DNA rereplication. This pathway may impact normal cells as they encounter stresses in their environment or during development or abnormal cells as they evolve metastatic potential. PMID:25775519

  18. The clinical development candidate CCT245737 is an orally active CHK1 inhibitor with preclinical activity in RAS mutant NSCLC and Eμ-MYC driven B-cell lymphoma

    PubMed Central

    Walton, Mike I.; Eve, Paul D.; Hayes, Angela; Henley, Alan T.; Valenti, Melanie R.; De Haven Brandon, Alexis K.; Box, Gary; Boxall, Kathy J.; Tall, Matthew; Swales, Karen; Matthews, Thomas P.; McHardy, Tatiana; Lainchbury, Michael; Osborne, James; Hunter, Jill E.; Perkins, Neil D.; Aherne, G. Wynne; Reader, John C.; Raynaud, Florence I.; Eccles, Suzanne A.; Collins, Ian; Garrett, Michelle D.

    2016-01-01

    CCT245737 is the first orally active, clinical development candidate CHK1 inhibitor to be described. The IC50 was 1.4nM against CHK1 enzyme and it exhibited>1,000-fold selectivity against CHK2 and CDK1. CCT245737 potently inhibited cellular CHK1 activity (IC50 30-220nM) and enhanced gemcitabine and SN38 cytotoxicity in multiple human tumor cell lines and human tumor xenograft models. Mouse oral bioavailability was complete (100%) with extensive tumor exposure. Genotoxic-induced CHK1 activity (pS296 CHK1) and cell cycle arrest (pY15 CDK1) were inhibited both in vitro and in human tumor xenografts by CCT245737, causing increased DNA damage and apoptosis. Uniquely, we show CCT245737 enhanced gemcitabine antitumor activity to a greater degree than for higher doses of either agent alone, without increasing toxicity, indicating a true therapeutic advantage for this combination. Furthermore, development of a novel ELISA assay for pS296 CHK1 autophosphorylation, allowed the quantitative measurement of target inhibition in a RAS mutant human tumor xenograft of NSCLC at efficacious doses of CCT245737. Finally, CCT245737 also showed significant single-agent activity against a MYC-driven mouse model of B-cell lymphoma. In conclusion, CCT245737 is a new CHK1 inhibitor clinical development candidate scheduled for a first in man Phase I clinical trial, that will use the novel pS296 CHK1 ELISA to monitor target inhibition. PMID:26295308

  19. The clinical development candidate CCT245737 is an orally active CHK1 inhibitor with preclinical activity in RAS mutant NSCLC and Eµ-MYC driven B-cell lymphoma.

    PubMed

    Walton, Mike I; Eve, Paul D; Hayes, Angela; Henley, Alan T; Valenti, Melanie R; De Haven Brandon, Alexis K; Box, Gary; Boxall, Kathy J; Tall, Matthew; Swales, Karen; Matthews, Thomas P; McHardy, Tatiana; Lainchbury, Michael; Osborne, James; Hunter, Jill E; Perkins, Neil D; Aherne, G Wynne; Reader, John C; Raynaud, Florence I; Eccles, Suzanne A; Collins, Ian; Garrett, Michelle D

    2016-01-19

    CCT245737 is the first orally active, clinical development candidate CHK1 inhibitor to be described. The IC50 was 1.4 nM against CHK1 enzyme and it exhibited>1,000-fold selectivity against CHK2 and CDK1. CCT245737 potently inhibited cellular CHK1 activity (IC50 30-220 nM) and enhanced gemcitabine and SN38 cytotoxicity in multiple human tumor cell lines and human tumor xenograft models. Mouse oral bioavailability was complete (100%) with extensive tumor exposure. Genotoxic-induced CHK1 activity (pS296 CHK1) and cell cycle arrest (pY15 CDK1) were inhibited both in vitro and in human tumor xenografts by CCT245737, causing increased DNA damage and apoptosis. Uniquely, we show CCT245737 enhanced gemcitabine antitumor activity to a greater degree than for higher doses of either agent alone, without increasing toxicity, indicating a true therapeutic advantage for this combination. Furthermore, development of a novel ELISA assay for pS296 CHK1 autophosphorylation, allowed the quantitative measurement of target inhibition in a RAS mutant human tumor xenograft of NSCLC at efficacious doses of CCT245737. Finally, CCT245737 also showed significant single-agent activity against a MYC-driven mouse model of B-cell lymphoma. In conclusion, CCT245737 is a new CHK1 inhibitor clinical development candidate scheduled for a first in man Phase I clinical trial, that will use the novel pS296 CHK1 ELISA to monitor target inhibition. PMID:26295308

  20. Zolpidem, triazolam, and diazepam decrease distress vocalizations in mouse pups: differential antagonism by flumazenil and beta-Carboline-3-carboxylate-t-butyl ester (beta-CCt).

    PubMed

    Rowlett, J K; Tornatzky, W; Cook, J M; Ma, C; Miczek, K A

    2001-04-01

    In response to stressful events, neonatal mice emit ultrasonic vocalizations (USVs), which are suppressed by BZ agonists. The present study examined the role of the benzodiazepine/alpha1 (BZ/alpha1) receptor subtype in the suppression engendered by the BZ/alpha1-preferring agonist zolpidem and the nonselective BZ agonists triazolam and diazepam. The role of BZ receptor subtypes was explored further by conducting antagonism studies using the BZ/alpha1-preferring antagonist beta-carboline-3-carboxylate-t-butyl ester (beta-CCt), in comparison with the nonselective BZ antagonist flumazenil. Mouse pups (CFW strain) were separated from their dam and littermates at day 7, and placed for 4 min in a test chamber with reduced ambient temperature (19 +/- 1 degrees C) for recording USVs, motor incoordination (measured as a pup rolling on its back per grid cross), and body temperature. Zolpidem, triazolam, and diazepam suppressed USVs in a dose-dependent manner, concomitant with increases in incoordination and augmentation of hypothermia. These effects of the three BZ agonists were blocked by flumazenil in a manner consistent with surmountable antagonism. The ability of zolpidem, but not triazolam or diazepam, to suppress USVs and augment hypothermia was antagonized by beta-CCt, whereas the increase in motor incoordination engendered by zolpidem, triazolam, and diazepam was not sensitive to beta-CCt administration. Collectively, these results suggest that zolpidem suppresses distress USVs in mouse pups by a mechanism distinct from that of typical BZs. Furthermore, suppression of distress USVs by zolpidem may involve BZ/alpha1 receptors and a nonanxiolytic mechanism, such as hypothermia. PMID:11259551

  1. Promoter-bound trinucleotide repeat mRNA drives epigenetic silencing in fragile X syndrome.

    PubMed

    Colak, Dilek; Zaninovic, Nikica; Cohen, Michael S; Rosenwaks, Zev; Yang, Wang-Yong; Gerhardt, Jeannine; Disney, Matthew D; Jaffrey, Samie R

    2014-02-28

    Epigenetic gene silencing is seen in several repeat-expansion diseases. In fragile X syndrome, the most common genetic form of mental retardation, a CGG trinucleotide-repeat expansion adjacent to the fragile X mental retardation 1 (FMR1) gene promoter results in its epigenetic silencing. Here, we show that FMR1 silencing is mediated by the FMR1 mRNA. The FMR1 mRNA contains the transcribed CGG-repeat tract as part of the 5' untranslated region, which hybridizes to the complementary CGG-repeat portion of the FMR1 gene to form an RNA·DNA duplex. Disrupting the interaction of the mRNA with the CGG-repeat portion of the FMR1 gene prevents promoter silencing. Thus, our data link trinucleotide-repeat expansion to a form of RNA-directed gene silencing mediated by direct interactions of the trinucleotide-repeat RNA and DNA. PMID:24578575

  2. Promoter-Bound Trinucleotide Repeat mRNA Drives Epigenetic Silencing in Fragile X Syndrome

    PubMed Central

    Colak, Dilek; Zaninovic, Nikica; Cohen, Michael S.; Rosenwaks, Zev; Yang, Wang-Yong; Gerhardt, Jeannine; Disney, Matthew D.; Jaffrey, Samie R.

    2015-01-01

    Epigenetic gene silencing is seen in several repeat-expansion diseases. In fragile X syndrome, the most common genetic form of mental retardation, a CGG trinucleotide–repeat expansion adjacent to the fragile X mental retardation 1 (FMR1) gene promoter results in its epigenetic silencing. Here, we show that FMR1 silencing is mediated by the FMR1 mRNA. The FMR1 mRNA contains the transcribed CGG-repeat tract as part of the 5′ untranslated region, which hybridizes to the complementary CGG-repeat portion of the FMR1 gene to form an RNA·DNA duplex. Disrupting the interaction of the mRNA with the CGG-repeat portion of the FMR1 gene prevents promoter silencing. Thus, our data link trinucleotide-repeat expansion to a form of RNA-directed gene silencing mediated by direct interactions of the trinucleotide-repeat RNA and DNA. PMID:24578575

  3. Saturation of repeated quantum measurements

    NASA Astrophysics Data System (ADS)

    Haapasalo, Erkka; Heinosaari, Teiko; Kuramochi, Yui

    2016-08-01

    We study sequential measurement scenarios where the system is repeatedly subjected to the same measurement process. We first provide examples of such repeated measurements where further repetitions of the measurement do not increase our knowledge on the system after some finite number of measurement steps. We also prove, however, that repeating the Lüders measurement of an unsharp two-outcome observable never saturates in this sense, and we characterize the observable measured in the limit of infinitely many repetitions. Our result implies that a repeated measurement can be used to correct the inherent noise of an unsharp observable.

  4. Repeated, but Not Acute, Stress Suppresses Inflammatory Plasma Extravasation

    NASA Astrophysics Data System (ADS)

    Strausbaugh, Holly J.; Dallman, Mary F.; Levine, Jon D.

    1999-12-01

    Clinical findings suggest that inflammatory disease symptoms are aggravated by ongoing, repeated stress, but not by acute stress. We hypothesized that, compared with single acute stressors, chronic repeated stress may engage different physiological mechanisms that exert qualitatively different effects on the inflammatory response. Because inhibition of plasma extravasation, a critical component of the inflammatory response, has been associated with increased disease severity in experimental arthritis, we tested for a potential repeated stress-induced inhibition of plasma extravasation. Repeated, but not single, exposures to restraint stress produced a profound inhibition of bradykinin-induced synovial plasma extravasation in the rat. Experiments examining the mechanism of inhibition showed that the effect of repeated stress was blocked by adrenalectomy, but not by adrenal medullae denervation, suggesting that the adrenal cortex mediates this effect. Consistent with known effects of stress and with mediation by the adrenal cortex, restraint stress evoked repeated transient elevations of plasma corticosterone levels. This elevated corticosterone was necessary and sufficient to produce inhibition of plasma extravasation because the stress-induced inhibition was blocked by preventing corticosterone synthesis and, conversely, induction of repeated transient elevations in plasma corticosterone levels mimicked the effects of repeated stress. These data suggest that repetition of a mild stressor can induce changes in the physiological state of the animal that enable a previously innocuous stressor to inhibit the inflammatory response. These findings provide a potential explanation for the clinical association between repeated stress and aggravation of inflammatory disease symptoms and provide a model for study of the biological mechanisms underlying the stress-induced aggravation of chronic inflammatory diseases.

  5. Expansion and Function of Repeat Domain Proteins During Stress and Development in Plants.

    PubMed

    Sharma, Manisha; Pandey, Girdhar K

    2015-01-01

    The recurrent repeats having conserved stretches of amino acids exists across all domains of life. Subsequent repetition of single sequence motif and the number and length of the minimal repeating motifs are essential characteristics innate to these proteins. The proteins with tandem peptide repeats are essential for providing surface to mediate protein-protein interactions for fundamental biological functions. Plants are enriched in tandem repeat containing proteins typically distributed into various families. This has been assumed that the occurrence of multigene repeats families in plants enable them to cope up with adverse environmental conditions and allow them to rapidly acclimatize to these conditions. The evolution, structure, and function of repeat proteins have been studied in all kingdoms of life. The presence of repeat proteins is particularly profuse in multicellular organisms in comparison to prokaryotes. The precipitous expansion of repeat proteins in plants is presumed to be through internal tandem duplications. Several repeat protein gene families have been identified in plants. Such as Armadillo (ARM), Ankyrin (ANK), HEAT, Kelch-like repeats, Tetratricopeptide (TPR), Leucine rich repeats (LRR), WD40, and Pentatricopeptide repeats (PPR). The structure and functions of these repeat proteins have been extensively studied in plants suggesting a critical role of these repeating peptides in plant cell physiology, stress and development. In this review, we illustrate the structural, functional, and evolutionary prospects of prolific repeat proteins in plants. PMID:26793205

  6. Expansion and Function of Repeat Domain Proteins During Stress and Development in Plants

    PubMed Central

    Sharma, Manisha; Pandey, Girdhar K.

    2016-01-01

    The recurrent repeats having conserved stretches of amino acids exists across all domains of life. Subsequent repetition of single sequence motif and the number and length of the minimal repeating motifs are essential characteristics innate to these proteins. The proteins with tandem peptide repeats are essential for providing surface to mediate protein–protein interactions for fundamental biological functions. Plants are enriched in tandem repeat containing proteins typically distributed into various families. This has been assumed that the occurrence of multigene repeats families in plants enable them to cope up with adverse environmental conditions and allow them to rapidly acclimatize to these conditions. The evolution, structure, and function of repeat proteins have been studied in all kingdoms of life. The presence of repeat proteins is particularly profuse in multicellular organisms in comparison to prokaryotes. The precipitous expansion of repeat proteins in plants is presumed to be through internal tandem duplications. Several repeat protein gene families have been identified in plants. Such as Armadillo (ARM), Ankyrin (ANK), HEAT, Kelch-like repeats, Tetratricopeptide (TPR), Leucine rich repeats (LRR), WD40, and Pentatricopeptide repeats (PPR). The structure and functions of these repeat proteins have been extensively studied in plants suggesting a critical role of these repeating peptides in plant cell physiology, stress and development. In this review, we illustrate the structural, functional, and evolutionary prospects of prolific repeat proteins in plants. PMID:26793205

  7. All-photonic quantum repeaters

    NASA Astrophysics Data System (ADS)

    Azuma, Koji; Tamaki, Kiyoshi; Lo, Hoi-Kwong

    2015-04-01

    Quantum communication holds promise for unconditionally secure transmission of secret messages and faithful transfer of unknown quantum states. Photons appear to be the medium of choice for quantum communication. Owing to photon losses, robust quantum communication over long lossy channels requires quantum repeaters. It is widely believed that a necessary and highly demanding requirement for quantum repeaters is the existence of matter quantum memories. Here we show that such a requirement is, in fact, unnecessary by introducing the concept of all-photonic quantum repeaters based on flying qubits. In particular, we present a protocol based on photonic cluster-state machine guns and a loss-tolerant measurement equipped with local high-speed active feedforwards. We show that, with such all-photonic quantum repeaters, the communication efficiency scales polynomially with the channel distance. Our result paves a new route towards quantum repeaters with efficient single-photon sources rather than matter quantum memories.

  8. All-photonic quantum repeaters.

    PubMed

    Azuma, Koji; Tamaki, Kiyoshi; Lo, Hoi-Kwong

    2015-01-01

    Quantum communication holds promise for unconditionally secure transmission of secret messages and faithful transfer of unknown quantum states. Photons appear to be the medium of choice for quantum communication. Owing to photon losses, robust quantum communication over long lossy channels requires quantum repeaters. It is widely believed that a necessary and highly demanding requirement for quantum repeaters is the existence of matter quantum memories. Here we show that such a requirement is, in fact, unnecessary by introducing the concept of all-photonic quantum repeaters based on flying qubits. In particular, we present a protocol based on photonic cluster-state machine guns and a loss-tolerant measurement equipped with local high-speed active feedforwards. We show that, with such all-photonic quantum repeaters, the communication efficiency scales polynomially with the channel distance. Our result paves a new route towards quantum repeaters with efficient single-photon sources rather than matter quantum memories. PMID:25873153

  9. All-photonic quantum repeaters

    PubMed Central

    Azuma, Koji; Tamaki, Kiyoshi; Lo, Hoi-Kwong

    2015-01-01

    Quantum communication holds promise for unconditionally secure transmission of secret messages and faithful transfer of unknown quantum states. Photons appear to be the medium of choice for quantum communication. Owing to photon losses, robust quantum communication over long lossy channels requires quantum repeaters. It is widely believed that a necessary and highly demanding requirement for quantum repeaters is the existence of matter quantum memories. Here we show that such a requirement is, in fact, unnecessary by introducing the concept of all-photonic quantum repeaters based on flying qubits. In particular, we present a protocol based on photonic cluster-state machine guns and a loss-tolerant measurement equipped with local high-speed active feedforwards. We show that, with such all-photonic quantum repeaters, the communication efficiency scales polynomially with the channel distance. Our result paves a new route towards quantum repeaters with efficient single-photon sources rather than matter quantum memories. PMID:25873153

  10. Sequence repeats and protein structure

    NASA Astrophysics Data System (ADS)

    Hoang, Trinh X.; Trovato, Antonio; Seno, Flavio; Banavar, Jayanth R.; Maritan, Amos

    2012-11-01

    Repeats are frequently found in known protein sequences. The level of sequence conservation in tandem repeats correlates with their propensities to be intrinsically disordered. We employ a coarse-grained model of a protein with a two-letter amino acid alphabet, hydrophobic (H) and polar (P), to examine the sequence-structure relationship in the realm of repeated sequences. A fraction of repeated sequences comprises a distinct class of bad folders, whose folding temperatures are much lower than those of random sequences. Imperfection in sequence repetition improves the folding properties of the bad folders while deteriorating those of the good folders. Our results may explain why nature has utilized repeated sequences for their versatility and especially to design functional proteins that are intrinsically unstructured at physiological temperatures.

  11. Estimating repeatability of egg size

    USGS Publications Warehouse

    Flint, P.L.; Rockwell, R.F.; Sedinger, J.S.

    2001-01-01

    Measures of repeatability have long been used to assess patterns of variation in egg size within and among females. We compared different analytical approaches for estimating repeatability of egg size of Black Brant. Separate estimates of repeatability for eggs of each clutch size and laying sequence number varied from 0.49 to 0.64. We suggest that using the averaging egg size within clutches results in underestimation of variation within females and thereby overestimates repeatability. We recommend a nested design that partitions egg-size variation within clutches, among clutches within females, and among females. We demonstrate little variation in estimates of repeatability resulting from a nested model controlling for egg laying sequence and a nested model in which we assumed laying sequence was unknown.

  12. Mechanisms of RNA-induced toxicity in CAG repeat disorders

    PubMed Central

    Nalavade, R; Griesche, N; Ryan, D P; Hildebrand, S; Krauß, S

    2013-01-01

    Several inherited neurodegenerative disorders are caused by CAG trinucleotide repeat expansions, which can be located either in the coding region or in the untranslated region (UTR) of the respective genes. Polyglutamine diseases (polyQ diseases) are caused by an expansion of a stretch of CAG repeats within the coding region, translating into a polyQ tract. The polyQ tract expansions result in conformational changes, eventually leading to aggregate formation. It is widely believed that the aggregation of polyQ proteins is linked with disease development. In addition, in the last couple of years, it has been shown that RNA-mediated mechanisms also have a profound role in neurotoxicity in both polyQ diseases and diseases caused by elongated CAG repeat motifs in their UTRs. Here, we review the different molecular mechanisms assigned to mRNAs with expanded CAG repeats. One aspect is the mRNA folding of CAG repeats. Furthermore, pathogenic mechanisms assigned to CAG repeat mRNAs are discussed. First, we discuss mechanisms that involve the sequestration of the diverse proteins to the expanded CAG repeat mRNA molecules. As a result of this, several cellular mechanisms are aberrantly regulated. These include the sequestration of MBNL1, leading to misregulated splicing; sequestration of nucleolin, leading to reduced cellular rRNA; and sequestration of proteins of the siRNA machinery, resulting in the production of short silencing RNAs that affect gene expression. Second, we discuss the effect of expanded CAG repeats on the subcellular localization, transcription and translation of the CAG repeat mRNA itself. Here we focus on the MID1 protein complex that triggers an increased translation of expanded CAG repeat mRNAs and a mechanism called repeat-associated non-ATG translation, which leads to proteins aberrantly translated from CAG repeat mRNAs. In addition, therapeutic approaches for CAG repeat disorders are discussed. Together, all the findings summarized here show that

  13. Mechanisms of RNA-induced toxicity in CAG repeat disorders.

    PubMed

    Nalavade, R; Griesche, N; Ryan, D P; Hildebrand, S; Krauss, S

    2013-01-01

    Several inherited neurodegenerative disorders are caused by CAG trinucleotide repeat expansions, which can be located either in the coding region or in the untranslated region (UTR) of the respective genes. Polyglutamine diseases (polyQ diseases) are caused by an expansion of a stretch of CAG repeats within the coding region, translating into a polyQ tract. The polyQ tract expansions result in conformational changes, eventually leading to aggregate formation. It is widely believed that the aggregation of polyQ proteins is linked with disease development. In addition, in the last couple of years, it has been shown that RNA-mediated mechanisms also have a profound role in neurotoxicity in both polyQ diseases and diseases caused by elongated CAG repeat motifs in their UTRs. Here, we review the different molecular mechanisms assigned to mRNAs with expanded CAG repeats. One aspect is the mRNA folding of CAG repeats. Furthermore, pathogenic mechanisms assigned to CAG repeat mRNAs are discussed. First, we discuss mechanisms that involve the sequestration of the diverse proteins to the expanded CAG repeat mRNA molecules. As a result of this, several cellular mechanisms are aberrantly regulated. These include the sequestration of MBNL1, leading to misregulated splicing; sequestration of nucleolin, leading to reduced cellular rRNA; and sequestration of proteins of the siRNA machinery, resulting in the production of short silencing RNAs that affect gene expression. Second, we discuss the effect of expanded CAG repeats on the subcellular localization, transcription and translation of the CAG repeat mRNA itself. Here we focus on the MID1 protein complex that triggers an increased translation of expanded CAG repeat mRNAs and a mechanism called repeat-associated non-ATG translation, which leads to proteins aberrantly translated from CAG repeat mRNAs. In addition, therapeutic approaches for CAG repeat disorders are discussed. Together, all the findings summarized here show that

  14. Protein Repeats from First Principles.

    PubMed

    Turjanski, Pablo; Parra, R Gonzalo; Espada, Rocío; Becher, Verónica; Ferreiro, Diego U

    2016-01-01

    Some natural proteins display recurrent structural patterns. Despite being highly similar at the tertiary structure level, repeating patterns within a single repeat protein can be extremely variable at the sequence level. We use a mathematical definition of a repetition and investigate the occurrences of these in sequences of different protein families. We found that long stretches of perfect repetitions are infrequent in individual natural proteins, even for those which are known to fold into structures of recurrent structural motifs. We found that natural repeat proteins are indeed repetitive in their families, exhibiting abundant stretches of 6 amino acids or longer that are perfect repetitions in the reference family. We provide a systematic quantification for this repetitiveness. We show that this form of repetitiveness is not exclusive of repeat proteins, but also occurs in globular domains. A by-product of this work is a fast quantification of the likelihood of a protein to belong to a family. PMID:27044676

  15. Protein Repeats from First Principles

    PubMed Central

    Turjanski, Pablo; Parra, R. Gonzalo; Espada, Rocío; Becher, Verónica; Ferreiro, Diego U.

    2016-01-01

    Some natural proteins display recurrent structural patterns. Despite being highly similar at the tertiary structure level, repeating patterns within a single repeat protein can be extremely variable at the sequence level. We use a mathematical definition of a repetition and investigate the occurrences of these in sequences of different protein families. We found that long stretches of perfect repetitions are infrequent in individual natural proteins, even for those which are known to fold into structures of recurrent structural motifs. We found that natural repeat proteins are indeed repetitive in their families, exhibiting abundant stretches of 6 amino acids or longer that are perfect repetitions in the reference family. We provide a systematic quantification for this repetitiveness. We show that this form of repetitiveness is not exclusive of repeat proteins, but also occurs in globular domains. A by-product of this work is a fast quantification of the likelihood of a protein to belong to a family. PMID:27044676

  16. Protein Repeats from First Principles

    NASA Astrophysics Data System (ADS)

    Turjanski, Pablo; Parra, R. Gonzalo; Espada, Rocío; Becher, Verónica; Ferreiro, Diego U.

    2016-04-01

    Some natural proteins display recurrent structural patterns. Despite being highly similar at the tertiary structure level, repeating patterns within a single repeat protein can be extremely variable at the sequence level. We use a mathematical definition of a repetition and investigate the occurrences of these in sequences of different protein families. We found that long stretches of perfect repetitions are infrequent in individual natural proteins, even for those which are known to fold into structures of recurrent structural motifs. We found that natural repeat proteins are indeed repetitive in their families, exhibiting abundant stretches of 6 amino acids or longer that are perfect repetitions in the reference family. We provide a systematic quantification for this repetitiveness. We show that this form of repetitiveness is not exclusive of repeat proteins, but also occurs in globular domains. A by-product of this work is a fast quantification of the likelihood of a protein to belong to a family.

  17. Archive of digital chirp subbottom profile data collected during USGS Cruise 13CCT04 offshore of Petit Bois Island, Mississippi, August 2013

    USGS Publications Warehouse

    Forde, Arnell S.; Flocks, James G.; Kindinger, Jack G.; Bernier, Julie C.; Kelso, Kyle W.; Wiese, Dana S.

    2015-01-01

    From August 13-23, 2013, the U.S. Geological Survey (USGS), in cooperation with the U.S. Army Corps of Engineers (USACE) conducted geophysical surveys to investigate the geologic controls on barrier island framework and long-term sediment transport offshore of Petit Bois Island, Mississippi. This investigation is part of a broader USGS study on Coastal Change and Transport (CCT). These surveys were funded through the Mississippi Coastal Improvements Program (MsCIP) with partial funding provided by the Northern Gulf of Mexico Ecosystem Change and Hazard Susceptibility Project. This report serves as an archive of unprocessed digital chirp subbottom data, trackline maps, navigation files, Geographic Information System (GIS) files, Field Activity Collection System (FACS) logs, and formal Federal Geographic Data Committee (FGDC) metadata. Gained-showing a relative increase in signal amplitude-digital images of the seismic profiles are provided.

  18. Mediation Analysis

    PubMed Central

    MacKinnon, David P.; Fairchild, Amanda J.; Fritz, Matthew S.

    2010-01-01

    Mediating variables are prominent in psychological theory and research. A mediating variable transmits the effect of an independent variable on a dependent variable. Differences between mediating variables and confounders, moderators, and covariates are outlined. Statistical methods to assess mediation and modern comprehensive approaches are described. Future directions for mediation analysis are discussed. PMID:16968208

  19. Limitations on quantum key repeaters.

    PubMed

    Bäuml, Stefan; Christandl, Matthias; Horodecki, Karol; Winter, Andreas

    2015-01-01

    A major application of quantum communication is the distribution of entangled particles for use in quantum key distribution. Owing to noise in the communication line, quantum key distribution is, in practice, limited to a distance of a few hundred kilometres, and can only be extended to longer distances by use of a quantum repeater, a device that performs entanglement distillation and quantum teleportation. The existence of noisy entangled states that are undistillable but nevertheless useful for quantum key distribution raises the question of the feasibility of a quantum key repeater, which would work beyond the limits of entanglement distillation, hence possibly tolerating higher noise levels than existing protocols. Here we exhibit fundamental limits on such a device in the form of bounds on the rate at which it may extract secure key. As a consequence, we give examples of states suitable for quantum key distribution but unsuitable for the most general quantum key repeater protocol. PMID:25903096

  20. Hysteresis of magnetostructural transitions: Repeatable and non-repeatable processes

    NASA Astrophysics Data System (ADS)

    Provenzano, Virgil; Della Torre, Edward; Bennett, Lawrence H.; ElBidweihy, Hatem

    2014-02-01

    The Gd5Ge2Si2 alloy and the off-stoichiometric Ni50Mn35In15 Heusler alloy belong to a special class of metallic materials that exhibit first-order magnetostructural transitions near room temperature. The magnetic properties of this class of materials have been extensively studied due to their interesting magnetic behavior and their potential for a number of technological applications such as refrigerants for near-room-temperature magnetic refrigeration. The thermally driven first-order transitions in these materials can be field-induced in the reverse order by applying a strong enough field. The field-induced transitions are typically accompanied by the presence of large magnetic hysteresis, the characteristics of which are a complicated function of temperature, field, and magneto-thermal history. In this study we show that the virgin curve, the major loop, and sequentially measured MH loops are the results of both repeatable and non-repeatable processes, in which the starting magnetostructural state, prior to the cycling of field, plays a major role. Using the Gd5Ge2Si2 and Ni50Mn35In15 alloys, as model materials, we show that a starting single phase state results in fully repeatable processes and large magnetic hysteresis, whereas a mixed phase starting state results in non-repeatable processes and smaller hysteresis.

  1. Repeating seismic events in China.

    PubMed

    Schaff, David P; Richards, Paul G

    2004-02-20

    About 10% of seismic events in and near China from 1985 to 2000 were repeating events not more than about 1 kilometer from each other. We cross-correlated seismograms from approximately 14,000 earthquakes and explosions and measured relative arrival times to approximately 0.01 second, enabling lateral location precision of about 100 to 300 meters. Such precision is important for seismic hazard studies, earthquake physics, and nuclear test ban verification. Recognition and measurement of repeating signals in archived data and the resulting improvement in location specificity quantifies the inaccuracy of current procedures for picking onset times and locating events. PMID:14976310

  2. Pure laparoscopic hepatectomy as repeat surgery and repeat hepatectomy

    PubMed Central

    Isetani, Masashi; Morise, Zenichi; Kawabe, Norihiko; Tomishige, Hirokazu; Nagata, Hidetoshi; Kawase, Jin; Arakawa, Satoshi

    2015-01-01

    AIM: To assess clinical outcomes of laparoscopic hepatectomy (LH) in patients with a history of upper abdominal surgery and repeat hepatectomy. METHODS: This study compared the perioperative courses of patients receiving LH at our institution that had or had not previously undergone upper abdominal surgery. Of the 80 patients who underwent LH, 22 had prior abdominal surgeries, including hepatectomy (n = 12), pancreatectomy (n = 3), cholecystectomy and common bile duct excision (n = 1), splenectomy (n = 1), total gastrectomy (n = 1), colectomy with the involvement of transverse colon (n = 3), and extended hysterectomy with extensive lymph-node dissection up to the upper abdomen (n = 1). Clinical indicators including operating time, blood loss, hospital stay, and morbidity were compared among the groups. RESULTS: Eighteen of the 22 patients who had undergone previous surgery had severe adhesions in the area around the liver. However, there were no conversions to laparotomy in this group. In the 58 patients without a history of upper abdominal surgery, the median operative time was 301 min and blood loss was 150 mL. In patients with upper abdominal surgical history or repeat hepatectomy, the operative times were 351 and 301 min, and blood loss was 100 and 50 mL, respectively. The median postoperative stay was 17, 13 and 12 d for patients with no history of upper abdominal surgery, patients with a history, and patients with repeat hepatectomy, respectively. There were five cases with complications in the group with no surgical history, compared to only one case in the group with a prior history. There were no statistically significant differences in the perioperative results between the groups with and without upper abdominal surgical history, or with repeat hepatectomy. CONCLUSION: LH is feasible and safe in patients with a history of upper abdominal surgery or repeat hepatectomy. PMID:25624731

  3. Do Twelfths Terminate or Repeat?

    ERIC Educational Resources Information Center

    Ambrose, Rebecca; Burnison, Erica

    2015-01-01

    When finding the decimal equivalent of a fraction with 12 in the denominator, will it terminate or repeat? This question came from a seventh grader in author Erica Burnison's class as the student was pondering a poster generated by one of her classmates. Not only was the question intriguing, but it also affirmed the belief in the power of…

  4. Pentapeptide Repeat Proteins and Cyanobacteria

    SciTech Connect

    Buchko, Garry W.

    2009-10-16

    Cyanobacteria are unique in many ways and one unusual feature is the presence of a suite of proteins that contain at least one domain with a minimum of eight tandem repeated five-residues (Rfr) of the general consensus sequence A[N/D]LXX. The function of such pentapeptide repeat proteins (PRPs) are still unknown, however, their prevalence in cyanobacteria suggests that they may play some role in the unique biological activities of cyanobacteria. As part of an inter-disciplinary Membrane Biology Grand Challenge at the Environmental Molecular Sciences Laboratory (Pacific Northwest National Laboratory) and Washington University in St. Louis, the genome of Cyanothece 51142 was sequenced and its molecular biology studied with relation to circadian rhythms. The genome of Cyanothece encodes for 35 proteins that contain at least one PRP domain. These proteins range in size from 105 (Cce_3102) to 930 (Cce_2929) kDa with the PRP domains ranging in predicted size from 12 (Cce_1545) to 62 (cce_3979) tandem pentapeptide repeats. Transcriptomic studies with 29 out of the 35 genes showed that at least three of the PRPs in Cyanothece 51142 (cce_0029, cce_3083, and cce_3272) oscillated with repeated periods of light and dark, further supporting a biological function for PRPs. Using X-ray diffraction crystallography, the structure for two pentapeptide repeat proteins from Cyanothece 51142 were determined, cce_1272 (aka Rfr32) and cce_4529 (aka Rfr23). Analysis of their molecular structures suggests that all PRP may share the same structural motif, a novel type of right-handed quadrilateral β-helix, or Rfr-fold, reminiscent of a square tower with four distinct faces. Each pentapeptide repeat occupies one face of the Rfr-fold with four consecutive pentapeptide repeats completing a coil that, in turn, stack upon each other to form “protein skyscrapers”. Details of the structural features of the Rfr-fold are reviewed here together with a discussion for the possible role of end

  5. Long Tract of Untranslated CAG Repeats Is Deleterious in Transgenic Mice

    PubMed Central

    Lin, Min-Jon; Li, Chui-Yen; Wang, Li-Chun; Chen, Luen-Kui; Pan, Huichin

    2011-01-01

    The most frequent trinucleotide repeat found in human disorders is the CAG sequence. Expansion of CAG repeats is mostly found in coding regions and is thought to cause diseases through a protein mechanism. Recently, expanded CAG repeats were shown to induce toxicity at the RNA level in Drosophila and C. elegans. These findings raise the possibility that CAG repeats may trigger RNA-mediated pathogenesis in mammals. Here, we demonstrate that transgenic mice expressing EGFP transcripts with long CAG repeats in the 3′ untranslated region develop pathogenic features. Expression of the transgene was directed to the muscle in order to compare the resulting phenotype to that caused by the CUG expansion, as occurs in myotonic dystrophy. Transgenic mice expressing 200, but not those expressing 0 or 23 CAG repeats, showed alterations in muscle morphology, histochemistry and electrophysiology, as well as abnormal behavioral phenotypes. Expression of the expanded CAG repeats in testes resulted in reduced fertility due to defective sperm motility. The production of EGFP protein was significantly reduced by the 200 CAG repeats, and no polyglutamine-containing product was detected, which argues against a protein mechanism. Moreover, nuclear RNA foci were detected for the long CAG repeats. These data support the notion that expanded CAG repeat RNA can cause deleterious effects in mammals. They also suggest the possible involvement of an RNA mechanism in human diseases with long CAG repeats. PMID:21283659

  6. The Diversity and Evolution of Wolbachia Ankyrin Repeat Domain Genes

    PubMed Central

    Siozios, Stefanos; Ioannidis, Panagiotis; Klasson, Lisa; Andersson, Siv G. E.; Braig, Henk R.; Bourtzis, Kostas

    2013-01-01

    Ankyrin repeat domain-encoding genes are common in the eukaryotic and viral domains of life, but they are rare in bacteria, the exception being a few obligate or facultative intracellular Proteobacteria species. Despite having a reduced genome, the arthropod strains of the alphaproteobacterium Wolbachia contain an unusually high number of ankyrin repeat domain-encoding genes ranging from 23 in wMel to 60 in wPip strain. This group of genes has attracted considerable attention for their astonishing large number as well as for the fact that ankyrin proteins are known to participate in protein-protein interactions, suggesting that they play a critical role in the molecular mechanism that determines host-Wolbachia symbiotic interactions. We present a comparative evolutionary analysis of the wMel-related ankyrin repeat domain-encoding genes present in different Drosophila-Wolbachia associations. Our results show that the ankyrin repeat domain-encoding genes change in size by expansion and contraction mediated by short directly repeated sequences. We provide examples of intra-genic recombination events and show that these genes are likely to be horizontally transferred between strains with the aid of bacteriophages. These results confirm previous findings that the Wolbachia genomes are evolutionary mosaics and illustrate the potential that these bacteria have to generate diversity in proteins potentially involved in the symbiotic interactions. PMID:23390535

  7. Excision of plastid marker genes using directly repeated DNA sequences.

    PubMed

    Mudd, Elisabeth A; Madesis, Panagiotis; Avila, Elena Martin; Day, Anil

    2014-01-01

    Excision of marker genes using DNA direct repeats makes use of the predominant homologous recombination pathways present in the plastids of algae and plants. The method is simple, efficient, and widely applicable to plants and microalgae. Marker excision frequency is dependent on the length and number of directly repeated sequences. When two repeats are used a repeat size of greater than 600 bp promotes efficient excision of the marker gene. A wide variety of sequences can be used to make the direct repeats. Only a single round of transformation is required, and there is no requirement to introduce site-specific recombinases by retransformation or sexual crosses. Selection is used to maintain the marker and ensure homoplasmy of transgenic plastid genomes. Release of selection allows the accumulation of marker-free plastid genomes generated by marker excision, which is spontaneous, random, and a unidirectional process. Positive selection is provided by linking marker excision to restoration of the coding region of an herbicide resistance gene from two overlapping but incomplete coding regions. Cytoplasmic sorting allows the segregation of cells with marker-free transgenic plastids. The marker-free shoots resulting from direct repeat-mediated excision of marker genes have been isolated by vegetative propagation of shoots in the T0 generation. Alternatively, accumulation of marker-free plastid genomes during growth, development and flowering of T0 plants allows the collection of seeds that give rise to a high proportion of marker-free T1 seedlings. The simplicity and convenience of direct repeat excision facilitates its widespread use to isolate marker-free crops. PMID:24599849

  8. Observations of Soft Gamma Repeaters

    NASA Technical Reports Server (NTRS)

    Kouveliotou, Chryssa

    2004-01-01

    Magnetars (Soft Gamma Repeaters and Anomalous X-ray Pulsars) are a subclass of neutron stars characterized by their recurrent X-ray bursts. While in an active (bursting) state (lasting anywhere between days and years), they are emit&ng hundreds of predominantly soft (kT=30 kev), short (0.1-100 ms long) events. Their quiescent source x-ray light ewes exhibit puhlions rotational period rate changes (spin-down) indicate that their magnetic fields are extremely high, of the order of 10^14- 10^l5 G. Such high B-field objects, dubbed "magnetars", had been predicted to exist in 1992, but the first concrete observational evidence were obtained in 1998 for two of these sources. I will discuss here the history of Soft Gamma Repeaters, and their spectral, timing and flux characteristics both in the persistent and their burst emission.

  9. A repeating fast radio burst.

    PubMed

    Spitler, L G; Scholz, P; Hessels, J W T; Bogdanov, S; Brazier, A; Camilo, F; Chatterjee, S; Cordes, J M; Crawford, F; Deneva, J; Ferdman, R D; Freire, P C C; Kaspi, V M; Lazarus, P; Lynch, R; Madsen, E C; McLaughlin, M A; Patel, C; Ransom, S M; Seymour, A; Stairs, I H; Stappers, B W; van Leeuwen, J; Zhu, W W

    2016-03-10

    Fast radio bursts are millisecond-duration astronomical radio pulses of unknown physical origin that appear to come from extragalactic distances. Previous follow-up observations have failed to find additional bursts at the same dispersion measure (that is, the integrated column density of free electrons between source and telescope) and sky position as the original detections. The apparent non-repeating nature of these bursts has led to the suggestion that they originate in cataclysmic events. Here we report observations of ten additional bursts from the direction of the fast radio burst FRB 121102. These bursts have dispersion measures and sky positions consistent with the original burst. This unambiguously identifies FRB 121102 as repeating and demonstrates that its source survives the energetic events that cause the bursts. Additionally, the bursts from FRB 121102 show a wide range of spectral shapes that appear to be predominantly intrinsic to the source and which vary on timescales of minutes or less. Although there may be multiple physical origins for the population of fast radio bursts, these repeat bursts with high dispersion measure and variable spectra specifically seen from the direction of FRB 121102 support an origin in a young, highly magnetized, extragalactic neutron star. PMID:26934226

  10. A repeating fast radio burst

    NASA Astrophysics Data System (ADS)

    Spitler, L. G.; Scholz, P.; Hessels, J. W. T.; Bogdanov, S.; Brazier, A.; Camilo, F.; Chatterjee, S.; Cordes, J. M.; Crawford, F.; Deneva, J.; Ferdman, R. D.; Freire, P. C. C.; Kaspi, V. M.; Lazarus, P.; Lynch, R.; Madsen, E. C.; McLaughlin, M. A.; Patel, C.; Ransom, S. M.; Seymour, A.; Stairs, I. H.; Stappers, B. W.; van Leeuwen, J.; Zhu, W. W.

    2016-03-01

    Fast radio bursts are millisecond-duration astronomical radio pulses of unknown physical origin that appear to come from extragalactic distances. Previous follow-up observations have failed to find additional bursts at the same dispersion measure (that is, the integrated column density of free electrons between source and telescope) and sky position as the original detections. The apparent non-repeating nature of these bursts has led to the suggestion that they originate in cataclysmic events. Here we report observations of ten additional bursts from the direction of the fast radio burst FRB 121102. These bursts have dispersion measures and sky positions consistent with the original burst. This unambiguously identifies FRB 121102 as repeating and demonstrates that its source survives the energetic events that cause the bursts. Additionally, the bursts from FRB 121102 show a wide range of spectral shapes that appear to be predominantly intrinsic to the source and which vary on timescales of minutes or less. Although there may be multiple physical origins for the population of fast radio bursts, these repeat bursts with high dispersion measure and variable spectra specifically seen from the direction of FRB 121102 support an origin in a young, highly magnetized, extragalactic neutron star.