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Sample records for finger transcriptional repressor

  1. Down-regulation of the zinc-finger homeobox protein TSHZ2 releases GLI1 from the nuclear repressor complex to restore its transcriptional activity during mammary tumorigenesis

    Science.gov (United States)

    Riku, Miho; Inaguma, Shingo; Ito, Hideaki; Tsunoda, Takumi; Ikeda, Hiroshi; Kasai, Kenji

    2016-01-01

    Although breast cancer is one of the most common malignancies, the molecular mechanisms underlying its development and progression are not fully understood. To identify key molecules involved, we screened publicly available microarray datasets for genes differentially expressed between breast cancers and normal mammary glands. We found that three of the genes predicted in this analysis were differentially expressed among human mammary tissues and cell lines. Of these genes, we focused on the role of the zinc-finger homeobox protein TSHZ2, which is down-regulated in breast cancer cells. We found that TSHZ2 is a nuclear protein harboring a bipartite nuclear localization signal, and we confirmed its function as a C-terminal binding protein (CtBP)-dependent transcriptional repressor. Through comprehensive screening, we identified TSHZ2-suppressing genes such as AEBP1 and CXCR4, which are conversely up-regulated by GLI1, the downstream transcription factor of Hedgehog signaling. We found that GLI1 forms a ternary complex with CtBP2 in the presence of TSHZ2 and that the transcriptional activity of GLI1 is suppressed by TSHZ2 in a CtBP-dependent manner. Indeed, knockdown of TSHZ2 increases the expression of AEBP1 and CXCR4 in TSHZ2-expressing immortalized mammary duct epithelium. Concordantly, immunohistochemical staining of mammary glands revealed that normal duct cells expresses GLI1 in the nucleus along with TSHZ2 and CtBP2, whereas invasive ductal carcinoma cells, which does not express TSHZ2, show the increase in the expression of AEBP1 and CXCR4 and in the cytoplasmic localization of GLI1. Thus, we propose that down-regulation of TSHZ2 is crucial for mammary tumorigenesis via the activation of GLI1. PMID:26744317

  2. The transcriptional repressor domain of Gli3 is intrinsically disordered

    DEFF Research Database (Denmark)

    Tsanev, Robert; Vanatalu, Kalju; Jarvet, Jüri

    2013-01-01

    The transcription factor Gli3 is acting mainly as a transcriptional repressor in the Sonic hedgehog signal transduction pathway. Gli3 contains a repressor domain in its N-terminus from residue G106 to E236. In this study we have characterized the intracellular structure of the Gli3 repressor doma...

  3. A novel GDNF-inducible gene, BMZF3, encodes a transcriptional repressor associated with KAP-1

    International Nuclear Information System (INIS)

    Suzuki, Chikage; Murakumo, Yoshiki; Kawase, Yukari; Sato, Tomoko; Morinaga, Takatoshi; Fukuda, Naoyuki; Enomoto, Atsushi; Ichihara, Masatoshi; Takahashi, Masahide

    2008-01-01

    The Krueppel-associated box (KRAB)-containing zinc finger proteins (ZFPs) comprise the largest family of zinc finger transcription factors that function as transcriptional repressors. In the study of glial cell line-derived neurotrophic factor (GDNF)-RET signaling, we have identified bone marrow zinc finger 3 (BMZF3), encoding a KRAB-ZFP, as a GDNF-inducible gene by differential display analysis. The expression of BMZF3 transcripts in the human neuroblastoma cell line TGW increased 1 h after GDNF stimulation, as determined by Northern blotting and quantitative reverse-transcriptase polymerase chain reaction. The BMZF3 possesses transcriptional repressor activity in the KRAB domain. BMZF3 interacts with a co-repressor protein, KRAB-associated protein 1 (KAP-1), through the KRAB domain and siRNA-mediated knockdown of KAP-1 abolished the transcriptional repressor activity of BMZF3, indicating that KAP-1 is necessary for BMZF3 function. Furthermore, siRNA-mediated silencing of BMZF3 inhibited cell proliferation. These findings suggest that BMZF3 is a transcriptional repressor induced by GDNF that plays a role in cell proliferation

  4. The transcriptional repressor domain of Gli3 is intrinsically disordered.

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    Robert Tsanev

    Full Text Available The transcription factor Gli3 is acting mainly as a transcriptional repressor in the Sonic hedgehog signal transduction pathway. Gli3 contains a repressor domain in its N-terminus from residue G106 to E236. In this study we have characterized the intracellular structure of the Gli3 repressor domain using a combined bioinformatics and experimental approach. According to our findings the Gli3 repressor domain while being intrinsically disordered contains predicted anchor sites for partner interactions. The obvious interaction partners to test were Ski and DNA; however, with both of these the structure of Gli3 repressor domain remained disordered. To locate residues important for the repressor function we mutated several residues within the Gli3 repressor domain. Two of these, H141A and H157N, targeting predicted helical regions, significantly decreased transcriptional repression and thus identify important functional parts of the domain.

  5. Transcriptional repressor DREAM regulates trigeminal noxious perception.

    Science.gov (United States)

    Benedet, Tomaso; Gonzalez, Paz; Oliveros, Juan C; Dopazo, Jose M; Ghimire, Kedar; Palczewska, Malgorzata; Mellstrom, Britt; Naranjo, Jose R

    2017-05-01

    Expression of the downstream regulatory element antagonist modulator (DREAM) protein in dorsal root ganglia and spinal cord is related to endogenous control mechanisms of acute and chronic pain. In primary sensory trigeminal neurons, high levels of endogenous DREAM protein are preferentially localized in the nucleus, suggesting a major transcriptional role. Here, we show that transgenic mice expressing a dominant active mutant of DREAM in trigeminal neurons show increased responses following orofacial sensory stimulation, which correlates with a decreased expression of prodynorphin and brain-derived neurotrophic factor in trigeminal ganglia. Genome-wide analysis of trigeminal neurons in daDREAM transgenic mice identified cathepsin L and the monoglyceride lipase as two new DREAM transcriptional targets related to pain. Our results suggest a role for DREAM in the regulation of trigeminal nociception. This article is part of the special article series "Pain". © 2016 International Society for Neurochemistry.

  6. Transcriptional repressor NIR interacts with the p53-inhibiting ubiquitin ligase MDM2.

    Science.gov (United States)

    Heyne, Kristina; Förster, Juliane; Schüle, Roland; Roemer, Klaus

    2014-04-01

    NIR (novel INHAT repressor) can bind to p53 at promoters and inhibit p53-mediated gene transactivation by blocking histone acetylation carried out by p300/CBP. Like NIR, the E3 ubiquitin ligase MDM2 can also bind and inhibit p53 at promoters. Here, we present data indicating that NIR, which shuttles between the nucleolus and nucleoplasm, not only binds to p53 but also directly to MDM2, in part via the central acidic and zinc finger domain of MDM2 that is also contacted by several other nucleolus-based MDM2/p53-regulating proteins. Like some of these, NIR was able to inhibit the ubiquitination of MDM2 and stabilize MDM2; however, unlike these nucleolus-based MDM2 regulators, NIR did not inhibit MDM2 to activate p53. Rather, NIR cooperated with MDM2 to repress p53-induced transactivation. This cooperative repression may at least in part involve p300/CBP. We show that NIR can block the acetylation of p53 and MDM2. Non-acetylated p53 has been documented previously to more readily associate with inhibitory MDM2. NIR may thus help to sustain the inhibitory p53:MDM2 complex, and we present evidence suggesting that all three proteins can indeed form a ternary complex. In sum, our findings suggest that NIR can support MDM2 to suppress p53 as a transcriptional activator.

  7. Groucho corepressor functions as a cofactor for the Knirps short-range transcriptional repressor.

    Science.gov (United States)

    Payankaulam, Sandhya; Arnosti, David N

    2009-10-13

    Despite the pervasive roles for repressors in transcriptional control, the range of action of these proteins on cis regulatory elements remains poorly understood. Knirps has essential roles in patterning the Drosophila embryo by means of short-range repression, an activity that is essential for proper regulation of complex transcriptional control elements. Short-range repressors function in a local fashion to interfere with the activity of activators or basal promoters within approximately 100 bp. In contrast, long-range repressors such as Hairy act over distances >1 kb. The functional distinction between these two classes of repressors has been suggested to stem from the differential recruitment of the CtBP corepressor to short-range repressors and Groucho to long-range repressors. Contrary to this differential recruitment model, we report that Groucho is a functional part of the Knirps short-range repression complex. The corepressor interaction is mediated via an eh-1 like motif present in the N terminus and a conserved region present in the central portion of Knirps. We also show that this interaction is important for the CtBP-independent repression activity of Knirps and is required for regulation of even-skipped. Our study uncovers a previously uncharacterized interaction between proteins previously thought to function in distinct repression pathways, and indicates that the Groucho corepressor can be differentially harnessed to execute short- and long-range repression.

  8. Whi7 is an unstable cell-cycle repressor of the Start transcriptional program.

    Science.gov (United States)

    Gomar-Alba, Mercè; Méndez, Ester; Quilis, Inma; Bañó, M Carmen; Igual, J Carlos

    2017-08-24

    Start is the main decision point in eukaryotic cell cycle in which cells commit to a new round of cell division. It involves the irreversible activation of a transcriptional program by G1 CDK-cyclin complexes through the inactivation of Start transcriptional repressors, Whi5 in yeast or Rb in mammals. Here we provide novel keys of how Whi7, a protein related at sequence level to Whi5, represses Start. Whi7 is an unstable protein, degraded by the SCF Grr1 ubiquitin-ligase, whose stability is cell cycle regulated by CDK1 phosphorylation. Importantly, Whi7 associates to G1/S gene promoters in late G1 acting as a repressor of SBF-dependent transcription. Our results demonstrate that Whi7 is a genuine paralog of Whi5. In fact, both proteins collaborate in Start repression bringing to light that yeast cells, as occurs in mammalian cells, rely on the combined action of multiple transcriptional repressors to block Start transition.The commitment of cells to a new cycle of division involves inactivation of the Start transcriptional repressor Whi5. Here the authors show that the sequence related protein Whi7 associates to G1/S gene promoters in late G1 and collaborates with Whi5 in Start repression.

  9. Targeted transcriptional repression using a chimeric TALE-SRDX repressor protein

    KAUST Repository

    Mahfouz, Magdy M.

    2011-12-14

    Transcriptional activator-like effectors (TALEs) are proteins secreted by Xanthomonas bacteria when they infect plants. TALEs contain a modular DNA binding domain that can be easily engineered to bind any sequence of interest, and have been used to provide user-selected DNA-binding modules to generate chimeric nucleases and transcriptional activators in mammalian cells and plants. Here we report the use of TALEs to generate chimeric sequence-specific transcriptional repressors. The dHax3 TALE was used as a scaffold to provide a DNA-binding module fused to the EAR-repression domain (SRDX) to generate a chimeric repressor that targets the RD29A promoter. The dHax3. SRDX protein efficiently repressed the transcription of the RD29A

  10. Regulation of gene expression by manipulating transcriptional repressor activity using a novel CoSRI technology.

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    Xu, Yue; Li, Song Feng; Parish, Roger W

    2017-07-01

    Targeted gene manipulation is a central strategy for studying gene function and identifying related biological processes. However, a methodology for manipulating the regulatory motifs of transcription factors is lacking as these factors commonly possess multiple motifs (e.g. repression and activation motifs) which collaborate with each other to regulate multiple biological processes. We describe a novel approach designated conserved sequence-guided repressor inhibition (CoSRI) that can specifically reduce or abolish the repressive activities of transcription factors in vivo. The technology was evaluated using the chimeric MYB80-EAR transcription factor and subsequently the endogenous WUS transcription factor. The technology was employed to develop a reversible male sterility system applicable to hybrid seed production. In order to determine the capacity of the technology to regulate the activity of endogenous transcription factors, the WUS repressor was chosen. The WUS repression motif could be inhibited in vivo and the transformed plants exhibited the wus-1 phenotype. Consequently, the technology can be used to manipulate the activities of transcriptional repressor motifs regulating beneficial traits in crop plants and other eukaryotic organisms. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  11. In vitro transcription accurately predicts lac repressor phenotype in vivo in Escherichia coli

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    Matthew Almond Sochor

    2014-07-01

    Full Text Available A multitude of studies have looked at the in vivo and in vitro behavior of the lac repressor binding to DNA and effector molecules in order to study transcriptional repression, however these studies are not always reconcilable. Here we use in vitro transcription to directly mimic the in vivo system in order to build a self consistent set of experiments to directly compare in vivo and in vitro genetic repression. A thermodynamic model of the lac repressor binding to operator DNA and effector is used to link DNA occupancy to either normalized in vitro mRNA product or normalized in vivo fluorescence of a regulated gene, YFP. An accurate measurement of repressor, DNA and effector concentrations were made both in vivo and in vitro allowing for direct modeling of the entire thermodynamic equilibrium. In vivo repression profiles are accurately predicted from the given in vitro parameters when molecular crowding is considered. Interestingly, our measured repressor–operator DNA affinity differs significantly from previous in vitro measurements. The literature values are unable to replicate in vivo binding data. We therefore conclude that the repressor-DNA affinity is much weaker than previously thought. This finding would suggest that in vitro techniques that are specifically designed to mimic the in vivo process may be necessary to replicate the native system.

  12. The transcriptional repressor DREAM is involved in thyroid gene expression

    International Nuclear Information System (INIS)

    D'Andrea, Barbara; Di Palma, Tina; Mascia, Anna; Motti, Maria Letizia; Viglietto, Giuseppe; Nitsch, Lucio; Zannini, Mariastella

    2005-01-01

    Downstream regulatory element antagonistic modulator (DREAM) was originally identified in neuroendocrine cells as a calcium-binding protein that specifically binds to downstream regulatory elements (DRE) on DNA, and represses transcription of its target genes. To explore the possibility that DREAM may regulate the endocrine activity of the thyroid gland, we analyzed its mRNA expression in undifferentiated and differentiated thyroid cells. We demonstrated that DREAM is expressed in the normal thyroid tissue as well as in differentiated thyroid cells in culture while it is absent in FRT poorly differentiated cells. In the present work, we also show that DREAM specifically binds to DRE sites identified in the 5' untranslated region (UTR) of the thyroid-specific transcription factors Pax8 and TTF-2/FoxE1 in a calcium-dependent manner. By gel retardation assays we demonstrated that thapsigargin treatment increases the binding of DREAM to the DRE sequences present in Pax8 and TTF-2/Foxe1 5' UTRs, and this correlates with a significant reduction of the expression of these genes. Interestingly, in poorly differentiated thyroid cells overexpression of exogenous DREAM strongly inhibits Pax8 expression. Moreover, we provide evidence that a mutated form of DREAM unable to bind Ca 2+ interferes with thyroid cell proliferation. Therefore, we propose that in thyroid cells DREAM is a mediator of the calcium-signaling pathway and it is involved in the regulation of thyroid cell function

  13. Clockwork orange encodes a transcriptional repressor important for circadian-clock amplitude in Drosophila.

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    Lim, Chunghun; Chung, Brian Y; Pitman, Jena L; McGill, Jermaine J; Pradhan, Suraj; Lee, Jongbin; Keegan, Kevin P; Choe, Joonho; Allada, Ravi

    2007-06-19

    Gene transcription is a central timekeeping process in animal clocks. In Drosophila, the basic helix-loop helix (bHLH)-PAS transcription-factor heterodimer, CLOCK/CYCLE (CLK/CYC), transcriptionally activates the clock components period (per), timeless (tim), Par domain protein 1 (Pdp1), and vrille (vri), which feed back and regulate distinct features of CLK/CYC function. Microarray studies have identified numerous rhythmically expressed transcripts, some of which are potential direct CLK targets. Here we demonstrate a circadian function for one such target, a bHLH-Orange repressor, CG17100/CLOCKWORK ORANGE (CWO). cwo is rhythmically expressed, and levels are reduced in Clk mutants, suggesting that cwo is CLK activated in vivo. cwo mutants display reduced-amplitude molecular and behavioral rhythms with lengthened periods. Molecular analysis suggests that CWO acts, in part, by repressing CLK target genes. We propose that CWO acts as a transcriptional and behavioral rhythm amplifier.

  14. clockwork orange encodes a transcriptional repressor important for circadian clock amplitude in Drosophila

    Science.gov (United States)

    Lim, Chunghun; Chung, Brian Y.; Pitman, Jena L.; McGill, Jermaine J.; Pradhan, Suraj; Lee, Jongbin; Keegan, Kevin P.; Choe, Joonho; Allada, Ravi

    2007-01-01

    Summary Gene transcription is a central timekeeping process in animal clocks. In Drosophila, the basic helix-loop helix (bHLH)-PAS transcription factor heterodimer, CLOCK (CLK)/CYCLE(CYC) transcriptionally activates the clock components period (per), timeless (tim), Par domain protein 1 (Pdp1), and vrille (vri) that feedback and regulate distinct features of CLK/CYC function [1]. Microarray studies have identified numerous rhythmically expressed transcripts [2-7], some of which are potential direct CLK targets [7]. Here we demonstrate a circadian function for one such target, a bHLH-Orange repressor CG17100/CLOCKWORK ORANGE (CWO). cwo is rhythmically expressed and levels are reduced in Clk mutants, suggesting that cwo is CLK-activated in vivo. cwo mutants display reduced amplitude molecular and behavioral rhythms with lengthened periods. Molecular analysis suggests CWO acts, in part, by repressing CLK target genes. We propose that CWO acts as a transcriptional and behavioral rhythm amplifier. PMID:17555964

  15. Transcriptional Co-repressor Function of the Hippo Pathway Transducers YAP and TAZ

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    Minchul Kim

    2015-04-01

    Full Text Available YAP (yes-associated protein and TAZ are oncogenic transcriptional co-activators downstream of the Hippo tumor-suppressor pathway. However, whether YAP and/or TAZ (YAP/TAZ engage in transcriptional co-repression remains relatively unexplored. Here, we directly demonstrated that YAP/TAZ represses numerous target genes, including tumor-suppressor genes such as DDIT4 (DNA-damage-inducible transcript 4 and Trail (TNF-related apoptosis-inducing ligand. Mechanistically, the repressor function of YAP/TAZ requires TEAD (TEA domain transcription factors. A YAP/TAZ-TEAD complex recruits the NuRD complex to deacetylate histones and alters nucleosome occupancy at target genes. Functionally, repression of DDIT4 and Trail by YAP/TAZ is required for mTORC1 (mechanistic target of rapamycin complex 1 activation and cell survival, respectively. Our demonstration of the transcriptional co-repressor activity of YAP/TAZ opens a new avenue for understanding the Hippo signaling pathway.

  16. Oct-1 acts as a transcriptional repressor on the C-reactive protein promoter

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    Voleti, Bhavya; Hammond, David J.; Thirumalai, Avinash; Agrawal, Alok

    2012-01-01

    C-reactive protein (CRP), a plasma protein of the innate immune system, is produced by hepatocytes. A critical regulatory region (−42 to −57) on the CRP promoter contains binding site for the IL-6-activated transcription factor C/EBPβ. The IL-1β-activated transcription factor NF-κB binds to a κB site located nearby (−63 to −74). The κB site overlaps an octamer motif (−59 to −66) which is the binding site for the constitutively active transcription factor Oct-1. Oct-1 is known to function both as a transcriptional repressor and as an activator depending upon the promoter context. Also, Oct-1 can regulate gene expression either by binding directly to the promoter or by interacting with other transcription factors bound to the promoter. The aim of this study was to investigate the functions of Oct-1 in regulating CRP expression. In luciferase transactivation assays, overexpressed Oct-1 inhibited (IL-6+IL-1β)-induced CRP expression in Hep3B cells. Deletion of the Oct-1 site from the promoter drastically reduced the cytokine response because the κB site was altered as a consequence of deleting the Oct-1 site. Surprisingly, overexpressed Oct-1 inhibited the residual (IL-6+IL-1β)-induced CRP expression through the promoter lacking the Oct-1 site. Similarly, deletion of the Oct-1 site reduced the induction of CRP expression in response to overexpressed C/EBPβ, and overexpressed Oct-1 inhibited C/EBPβ-induced CRP expression through the promoter lacking the Oct-1 site. We conclude that Oct-1 acts as a transcriptional repressor of CRP expression and it does so by occupying its cognate site on the promoter and also via other transcription factors by an as yet undefined mechanism. PMID:22750226

  17. Genetic Deletion of the Transcriptional Repressor NFIL3 Enhances Axon Growth In Vitro but Not Axonal Repair In Vivo

    NARCIS (Netherlands)

    van der Kallen, Loek R; Eggers, Ruben; Ehlert, Erich M; Verhaagen, J.; Smit, August B; van Kesteren, Ronald E

    2015-01-01

    Axonal regeneration after injury requires the coordinated expression of genes in injured neurons. We previously showed that either reducing expression or blocking function of the transcriptional repressor NFIL3 activates transcription of regeneration-associated genes Arg1 and Gap43 and strongly

  18. The homeobox gene Mohawk represses transcription by recruiting the sin3A/HDAC co-repressor complex.

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    Anderson, Douglas M; Beres, Brian J; Wilson-Rawls, Jeanne; Rawls, Alan

    2009-03-01

    Mohawk is an atypical homeobox gene expressed in embryonic progenitor cells of skeletal muscle, tendon, and cartilage. We demonstrate that Mohawk functions as a transcriptional repressor capable of blocking the myogenic conversion of 10T1/2 fibroblasts. The repressor activity is located in three small, evolutionarily conserved domains (MRD1-3) in the carboxy-terminal half of the protein. Point mutation analysis revealed six residues in MRD1 are sufficient for repressor function. The carboxy-terminal half of Mohawk is able to recruit components of the Sin3A/HDAC co-repressor complex (Sin3A, Hdac1, and Sap18) and a subset of Polymerase II general transcription factors (Tbp, TFIIA1 and TFIIB). Furthermore, Sap18, a protein that bridges the Sin3A/HDAC complex to DNA-bound transcription factors, is co-immunoprecipitated by MRD1. These data predict that Mohawk can repress transcription through recruitment of the Sin3A/HDAC co-repressor complex, and as a result, repress target genes required for the differentiation of cells to the myogenic lineage. (c) 2009 Wiley-Liss, Inc.

  19. Clockwork Orange is a transcriptional repressor and a new Drosophila circadian pacemaker component.

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    Kadener, Sebastian; Stoleru, Dan; McDonald, Michael; Nawathean, Pipat; Rosbash, Michael

    2007-07-01

    Many organisms use circadian clocks to keep temporal order and anticipate daily environmental changes. In Drosophila, the master clock gene Clock promotes the transcription of several key target genes. Two of these gene products, PER and TIM, repress CLK-CYC-mediated transcription. To recognize additional direct CLK target genes, we designed a genome-wide approach and identified clockwork orange (cwo) as a new core clock component. cwo encodes a transcriptional repressor that synergizes with PER and inhibits CLK-mediated activation. Consistent with this function, the mRNA profiles of CLK direct target genes in cwo mutant flies manifest high trough values and low amplitude oscillations. Because behavioral rhythmicity fails to persist in constant darkness (DD) with little or no effect on average mRNA levels in flies lacking cwo, transcriptional oscillation amplitude appears to be linked to rhythmicity. Moreover, the mutant flies are long period, consistent with the late repression indicated by the RNA profiles. These findings suggest that CWO acts preferentially in the late night to help terminate CLK-CYC-mediated transcription of direct target genes including cwo itself. The presence of mammalian homologs with circadian expression features (Dec1 and Dec2) suggests that a similar feedback mechanism exists in mammalian clocks.

  20. FOXP3 is a novel transcriptional repressor for the breast cancer oncogene SKP2.

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    Zuo, Tao; Liu, Runhua; Zhang, Huiming; Chang, Xing; Liu, Yan; Wang, Lizhong; Zheng, Pan; Liu, Yang

    2007-12-01

    S-phase kinase-associated protein 2 (SKP2) is a component of the E3 ubiquitin ligase SKP1-Cul1-Fbox complex. Overexpression of SKP2 results in cell cycle dysregulation and carcinogenesis; however, the genetic lesions that cause this upregulation are poorly understood. We recently demonstrated that forkhead box P3 (FOXP3) is an X-linked breast cancer suppressor and an important repressor of the oncogene ERBB2/HER2. Since FOXP3 suppresses tumor growth regardless of whether the tumors overexpress ERBB2/HER2, additional FOXP3 targets may be involved in its tumor suppressor activity. Here, we show that mammary carcinomas from mice heterozygous for a Foxp3 mutation exhibited increased Skp2 expression. Ectopic expression of FOXP3 in mouse mammary cancer cells repressed SKP2 expression with a corresponding increase in p27 and polyploidy. Conversely, siRNA silencing of the FOXP3 gene in human mammary epithelial cells increased SKP2 expression. We also show that Foxp3 directly interacted with and repressed the Skp2 promoter. Moreover, the analysis of over 200 primary breast cancer samples revealed an inverse correlation between FOXP3 and SKP2 levels. Finally, we demonstrated that downregulation of SKP2 was critical for FOXP3-mediated growth inhibition in breast cancer cells that do not overexpress ERBB2/HER2. Our data provide genetic, biochemical, and functional evidence that FOXP3 is a novel transcriptional repressor for the oncogene SKP2.

  1. Mouse Hobit is a homolog of the transcriptional repressor Blimp-1 that regulates NKT cell effector differentiation

    NARCIS (Netherlands)

    van Gisbergen, Klaas P. J. M.; Kragten, Natasja A. M.; Hertoghs, Kirsten M. L.; Wensveen, Felix M.; Jonjic, Stipan; Hamann, Jörg; Nolte, Martijn A.; van Lier, Rene A. W.

    2012-01-01

    The transcriptional repressor Blimp-1 mediates the terminal differentiation of many cell types, including T cells. Here we identified Hobit (Znf683) as a previously unrecognized homolog of Blimp-1 that was specifically expressed in mouse natural killer T cells (NKT cells). Through studies of

  2. The banana fruit Dof transcription factor MaDof23 acts as a repressor and interacts with MaERF9 in regulating ripening-related genes.

    Science.gov (United States)

    Feng, Bi-hong; Han, Yan-chao; Xiao, Yun-yi; Kuang, Jian-fei; Fan, Zhong-qi; Chen, Jian-ye; Lu, Wang-jin

    2016-04-01

    The DNA binding with one finger (Dof) proteins, a family of plant-specific transcription factors, are involved in a variety of plant biological processes. However, little information is available on their involvement in fruit ripening. We have characterized 25 MaDof genes from banana fruit (Musa acuminata), designated as MaDof1-MaDof25 Gene expression analysis in fruit subjected to different ripening conditions revealed that MaDofs were differentially expressed during different stages of ripening. MaDof10, 23, 24, and 25 were ethylene-inducible and nuclear-localized, and their transcript levels increased during fruit ripening. Moreover, yeast two-hybrid and bimolecular fluorescence complementation analyses demonstrated a physical interaction between MaDof23 and MaERF9, a potential regulator of fruit ripening reported in a previous study. We determined that MaDof23 is a transcriptional repressor, whereas MaERF9 is a transcriptional activator. We suggest that they might act antagonistically in regulating 10 ripening-related genes, including MaEXP1/2/3/5, MaXET7, MaPG1, MaPME3, MaPL2, MaCAT, and MaPDC, which are associated with cell wall degradation and aroma formation. Taken together, our findings provide new insight into the transcriptional regulation network controlling banana fruit ripening. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  3. Inhibition of Snail Family Transcriptional Repressor 2 (SNAI2 Enhances Multidrug Resistance of Hepatocellular Carcinoma Cells.

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    Xin-Yu Zhao

    Full Text Available China accounts for almost half of the total number of liver cancer cases and deaths worldwide, and hepatocellular carcinoma (HCC is the most primary liver cancer. Snail family transcriptional repressor 2 (SNAI2 is known as an epithelial to mesenchymal transition-inducing transcription factor that drives neoplastic epithelial cells into mesenchymal phenotype. However, the roles of endogenous SNAI2 remain controversial in different types of malignant tumors. Herein, we surprisingly identify that anchorage-independent growth, including the formation of tumor sphere and soft agar colony, is significantly increased when SNAI2 expression is inhibited by shRNAs in HCC cells. Suppression of SNAI2 suffices to up-regulate several cancer stem genes. Although unrelated to the metastatic ability, SNAI2 inhibition does increase the efflux of Hoechst 33342 and enhance multidrug resistance in vitro and in vivo. In agreement with this data, we demonstrate for the first time that decreasing SNAI2 level can transcriptionally upregulate several ATP binding cassette (ABC transporter genes such as ABCB1. Moreover, ABC transporters' inhibitor verapamil can rescue the multidrug resistance induced by SNAI2 inhibition. Our results implicate that SNAI2 behaves as a tumor suppressor by inhibiting multidrug resistance via suppressing ABC transporter genes in HCC cells.

  4. The B-subdomain of the Xenopus laevis XFIN KRAB-AB domain is responsible for its weaker transcriptional repressor activity compared to human ZNF10/Kox1.

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    Nadine Born

    Full Text Available The Krüppel-associated box (KRAB domain interacts with the nuclear hub protein TRIM28 to initiate or mediate chromatin-dependent processes like transcriptional repression, imprinting or suppression of endogenous retroviruses. The prototype KRAB domain initially identified in ZNF10/KOX1 encompasses two subdomains A and B that are found in hundreds of zinc finger transcription factors studied in human and murine genomes. Here we demonstrate for the first time transcriptional repressor activity of an amphibian KRAB domain. After sequence correction, the updated KRAB-AB domain of zinc finger protein XFIN from the frog Xenopus laevis was found to confer transcriptional repression in reporter assays in Xenopus laevis A6 kidney cells as well as in human HeLa, but not in the minnow Pimephales promelas fish cell line EPC. Binding of the XFIN KRAB-AB domain to human TRIM28 was demonstrated in a classical co-immunoprecipitation approach and visualized in a single-cell compartmentalization assay. XFIN-AB displayed reduced potency in repression as well as lower strength of interaction with TRIM28 compared to ZNF10 KRAB-AB. KRAB-B subdomain swapping between the two KRAB domains indicated that it was mainly the KRAB-B subdomain of XFIN that was responsible for its lower capacity in repression and binding to human TRIM28. In EPC fish cells, ZNF10 and XFIN KRAB repressor activity could be partially restored to low levels by adding exogenous human TRIM28. In contrast to XFIN, we did not find any transcriptional repression activity for the KRAB-like domain of human PRDM9 in HeLa cells. PRDM9 is thought to harbor an evolutionary older domain related to KRAB whose homologs even occur in invertebrates. Our results support the notion that functional bona fide KRAB domains which confer transcriptional repression and interact with TRIM28 most likely co-evolved together with TRIM28 at the beginning of tetrapode evolution.

  5. THAP5 is a DNA-binding transcriptional repressor that is regulated in melanoma cells during DNA damage-induced cell death

    International Nuclear Information System (INIS)

    Balakrishnan, Meenakshi P.; Cilenti, Lucia; Ambivero, Camilla; Goto, Yamafumi; Takata, Minoru; Turkson, James; Li, Xiaoman Shawn; Zervos, Antonis S.

    2011-01-01

    Research highlights: → THAP5 is a DNA-binding protein and a transcriptional repressor. → THAP5 is induced in melanoma cells upon exposure to UV or treatment with cisplatin. → THAP5 induction correlates with the degree of apoptosis in melanoma cell population. → THAP5 is a pro-apoptotic protein involved in melanoma cell death. -- Abstract: THAP5 was originally isolated as a specific interactor and substrate of the mitochondrial pro-apoptotic Omi/HtrA2 protease. It is a human zinc finger protein characterized by a restricted pattern of expression and the lack of orthologs in mouse and rat. The biological function of THAP5 is unknown but our previous studies suggest it could regulate G2/M transition in kidney cells and could be involved in human cardiomyocyte cell death associated with coronary artery disease (CAD). In this report, we expanded our studies on the properties and function of THAP5 in human melanoma cells. THAP5 was expressed in primary human melanocytes as well as in all melanoma cell lines that were tested. THAP5 protein level was significantly induced by UV irradiation or cisplatin treatment, conditions known to cause DNA damage. The induction of THAP5 correlated with a significant increase in apoptotic cell death. In addition, we show that THAP5 is a nuclear protein that could recognize and bind a specific DNA motif. THAP5 could also repress the transcription of a reporter gene in a heterologous system. Our work suggests that THAP5 is a DNA-binding protein and a transcriptional repressor. Furthermore, THAP5 has a pro-apoptotic function and it was induced in melanoma cells under conditions that promoted cell death.

  6. THAP5 is a DNA-binding transcriptional repressor that is regulated in melanoma cells during DNA damage-induced cell death

    Energy Technology Data Exchange (ETDEWEB)

    Balakrishnan, Meenakshi P.; Cilenti, Lucia; Ambivero, Camilla [Biomolecular Science Center, Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL (United States); Goto, Yamafumi [Department of Dermatology, Shinshu University School of Medicine, Matsumoto (Japan); Takata, Minoru [Department of Dermatology, Okayama University Graduate School of Medical Dentistry and Pharmaceutical Sciences, Okayama (Japan); Turkson, James; Li, Xiaoman Shawn [Biomolecular Science Center, Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL (United States); Zervos, Antonis S., E-mail: azervos@mail.ucf.edu [Biomolecular Science Center, Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL (United States)

    2011-01-07

    Research highlights: {yields} THAP5 is a DNA-binding protein and a transcriptional repressor. {yields} THAP5 is induced in melanoma cells upon exposure to UV or treatment with cisplatin. {yields} THAP5 induction correlates with the degree of apoptosis in melanoma cell population. {yields} THAP5 is a pro-apoptotic protein involved in melanoma cell death. -- Abstract: THAP5 was originally isolated as a specific interactor and substrate of the mitochondrial pro-apoptotic Omi/HtrA2 protease. It is a human zinc finger protein characterized by a restricted pattern of expression and the lack of orthologs in mouse and rat. The biological function of THAP5 is unknown but our previous studies suggest it could regulate G2/M transition in kidney cells and could be involved in human cardiomyocyte cell death associated with coronary artery disease (CAD). In this report, we expanded our studies on the properties and function of THAP5 in human melanoma cells. THAP5 was expressed in primary human melanocytes as well as in all melanoma cell lines that were tested. THAP5 protein level was significantly induced by UV irradiation or cisplatin treatment, conditions known to cause DNA damage. The induction of THAP5 correlated with a significant increase in apoptotic cell death. In addition, we show that THAP5 is a nuclear protein that could recognize and bind a specific DNA motif. THAP5 could also repress the transcription of a reporter gene in a heterologous system. Our work suggests that THAP5 is a DNA-binding protein and a transcriptional repressor. Furthermore, THAP5 has a pro-apoptotic function and it was induced in melanoma cells under conditions that promoted cell death.

  7. Evolutionary expansion and divergence in a large family of primate-specific zinc finger transcription factor genes

    Energy Technology Data Exchange (ETDEWEB)

    Hamilton, A T; Huntley, S; Tran-Gyamfi, M; Baggott, D; Gordon, L; Stubbs, L

    2005-09-28

    Although most genes are conserved as one-to-one orthologs in different mammalian orders, certain gene families have evolved to comprise different numbers and types of protein-coding genes through independent series of gene duplications, divergence and gene loss in each evolutionary lineage. One such family encodes KRAB-zinc finger (KRAB-ZNF) genes, which are likely to function as transcriptional repressors. One KRAB-ZNF subfamily, the ZNF91 clade, has expanded specifically in primates to comprise more than 110 loci in the human genome, yielding large gene clusters in human chromosomes 19 and 7 and smaller clusters or isolated copies at other chromosomal locations. Although phylogenetic analysis indicates that many of these genes arose before the split between old world monkeys and new world monkeys, the ZNF91 subfamily has continued to expand and diversify throughout the evolution of apes and humans. The paralogous loci are distinguished by sequence divergence within their zinc finger arrays indicating a selection for proteins with different DNA binding specificities. RT-PCR and in situ hybridization data show that some of these ZNF genes can have tissue-specific expression patterns, however many KRAB-ZNFs that are near-ubiquitous could also be playing very specific roles in halting target pathways in all tissues except for a few, where the target is released by the absence of its repressor. The number of variant KRAB-ZNF proteins is increased not only because of the large number of loci, but also because many loci can produce multiple splice variants, which because of the modular structure of these genes may have separate and perhaps even conflicting regulatory roles. The lineage-specific duplication and rapid divergence of this family of transcription factor genes suggests a role in determining species-specific biological differences and the evolution of novel primate traits.

  8. Variation in auxin sensing guides AUX/IAA transcriptional repressor ubiquitylation and destruction.

    Science.gov (United States)

    Winkler, Martin; Niemeyer, Michael; Hellmuth, Antje; Janitza, Philipp; Christ, Gideon; Samodelov, Sophia L; Wilde, Verona; Majovsky, Petra; Trujillo, Marco; Zurbriggen, Matias D; Hoehenwarter, Wolfgang; Quint, Marcel; Calderón Villalobos, Luz Irina A

    2017-06-07

    Auxin is a small molecule morphogen that bridges SCF TIR1/AFB -AUX/IAA co-receptor interactions leading to ubiquitylation and proteasome-dependent degradation of AUX/IAA transcriptional repressors. Here, we systematically dissect auxin sensing by SCF TIR1 -IAA6 and SCF TIR1 -IAA19 co-receptor complexes, and assess IAA6/IAA19 ubiquitylation in vitro and IAA6/IAA19 degradation in vivo. We show that TIR1-IAA19 and TIR1-IAA6 have distinct auxin affinities that correlate with ubiquitylation and turnover dynamics of the AUX/IAA. We establish a system to track AUX/IAA ubiquitylation in IAA6 and IAA19 in vitro and show that it occurs in flexible hotspots in degron-flanking regions adorned with specific Lys residues. We propose that this signature is exploited during auxin-mediated SCF TIR1 -AUX/IAA interactions. We present evidence for an evolving AUX/IAA repertoire, typified by the IAA6/IAA19 ohnologues, that discriminates the range of auxin concentrations found in plants. We postulate that the intrinsic flexibility of AUX/IAAs might bias their ubiquitylation and destruction kinetics enabling specific auxin responses.

  9. Nucleolin modulates the subcellular localization of GDNF-inducible zinc finger protein 1 and its roles in transcription and cell proliferation

    International Nuclear Information System (INIS)

    Dambara, Atsushi; Morinaga, Takatoshi; Fukuda, Naoyuki; Yamakawa, Yoshinori; Kato, Takuya; Enomoto, Atsushi; Asai, Naoya; Murakumo, Yoshiki; Matsuo, Seiichi; Takahashi, Masahide

    2007-01-01

    GZF1 is a zinc finger protein induced by glial cell-line-derived neurotrophic factor (GDNF). It is a sequence-specific transcriptional repressor with a BTB/POZ (Broad complex, Tramtrack, Bric a brac/Poxvirus and zinc finger) domain and ten zinc finger motifs. In the present study, we used immunoprecipitation and mass spectrometry to identify nucleolin as a GZF1-binding protein. Deletion analysis revealed that zinc finger motifs 1-4 of GZF1 mediate its association with nucleolin. When zinc fingers 1-4 were deleted from GZF1 or nucleolin expression was knocked down by short interference RNA (siRNA), nuclear localization of GZF1 was impaired. These results suggest that nucleolin is involved in the proper subcellular distribution of GZF1. In addition, overexpression of nucleolin moderately inhibited the transcriptional repressive activity of GZF1 whereas knockdown of nucleolin expression by siRNA enhanced its activity. Thus, the repressive activity of GZF1 is modulated by the level at which nucleolin is expressed. Finally, we found that knockdown of GZF1 and nucleolin expression markedly impaired cell proliferation. These findings suggest that the physiological functions of GZF1 may be regulated by the protein's association with nucleolin

  10. Transcriptional repressor Tbx3 is required for the hormone-sensing cell lineage in mammary epithelium.

    Directory of Open Access Journals (Sweden)

    Kamini Kunasegaran

    Full Text Available The transcriptional repressor Tbx3 is involved in lineage specification in several tissues during embryonic development. Germ-line mutations in the Tbx3 gene give rise to Ulnar-Mammary Syndrome (comprising reduced breast development and Tbx3 is required for mammary epithelial cell identity in the embryo. Notably Tbx3 has been implicated in breast cancer, which develops in adult mammary epithelium, but the role of Tbx3 in distinct cell types of the adult mammary gland has not yet been characterized. Using a fluorescent reporter knock-in mouse, we show that in adult virgin mice Tbx3 is highly expressed in luminal cells that express hormone receptors, and not in luminal cells of the alveolar lineage (cells primed for milk production. Flow cytometry identified Tbx3 expression already in progenitor cells of the hormone-sensing lineage and co-immunofluorescence confirmed a strict correlation between estrogen receptor (ER and Tbx3 expression in situ. Using in vivo reconstitution assays we demonstrate that Tbx3 is functionally relevant for this lineage because knockdown of Tbx3 in primary mammary epithelial cells prevented the formation of ER+ cells, but not luminal ER- or basal cells. Interestingly, genes that are repressed by Tbx3 in other cell types, such as E-cadherin, are not repressed in hormone-sensing cells, highlighting that transcriptional targets of Tbx3 are cell type specific. In summary, we provide the first analysis of Tbx3 expression in the adult mammary gland at a single cell level and show that Tbx3 is important for the generation of hormone-sensing cells.

  11. Regulation of Nitrogen Metabolism by GATA Zinc Finger Transcription Factors in Yarrowia lipolytica

    Energy Technology Data Exchange (ETDEWEB)

    Pomraning, Kyle R.; Bredeweg, Erin L.; Baker, Scott E.

    2017-02-15

    ABSTRACT

    Fungi accumulate lipids in a manner dependent on the quantity and quality of the nitrogen source on which they are growing. In the oleaginous yeastYarrowia lipolytica, growth on a complex source of nitrogen enables rapid growth and limited accumulation of neutral lipids, while growth on a simple nitrogen source promotes lipid accumulation in large lipid droplets. Here we examined the roles of nitrogen catabolite repression and its regulation by GATA zinc finger transcription factors on lipid metabolism inY. lipolytica. Deletion of the GATA transcription factor genesgzf3andgzf2resulted in nitrogen source-specific growth defects and greater accumulation of lipids when the cells were growing on a simple nitrogen source. Deletion ofgzf1, which is most similar to activators of genes repressed by nitrogen catabolite repression in filamentous ascomycetes, did not affect growth on the nitrogen sources tested. We examined gene expression of wild-type and GATA transcription factor mutants on simple and complex nitrogen sources and found that expression of enzymes involved in malate metabolism, beta-oxidation, and ammonia utilization are strongly upregulated on a simple nitrogen source. Deletion ofgzf3results in overexpression of genes with GATAA sites in their promoters, suggesting that it acts as a repressor, whilegzf2is required for expression of ammonia utilization genes but does not grossly affect the transcription level of genes predicted to be controlled by nitrogen catabolite repression. Both GATA transcription factor mutants exhibit decreased expression of genes controlled by carbon catabolite repression via the repressormig1, including genes for beta-oxidation, highlighting the complex interplay between regulation of carbon, nitrogen, and lipid metabolism.

    IMPORTANCENitrogen source is

  12. Transcription Factor Ets-2 Acts as a Preinduction Repressor of Interleukin-2 (IL-2) Transcription in Naive T Helper Lymphocytes.

    Science.gov (United States)

    Panagoulias, Ioannis; Georgakopoulos, Tassos; Aggeletopoulou, Ioanna; Agelopoulos, Marios; Thanos, Dimitris; Mouzaki, Athanasia

    2016-12-23

    IL-2 is the first cytokine produced when naive T helper (Th) cells are activated and differentiate into dividing pre-Th0 proliferating precursors. IL-2 expression is blocked in naive, but not activated or memory, Th cells by the transcription factor Ets-2 that binds to the antigen receptor response element (ARRE)-2 of the proximal IL-2 promoter. Ets-2 acts as an independent preinduction repressor in naive Th cells and does not interact physically with the transcription factor NFAT (nuclear factor of activated T-cells) that binds to the ARRE-2 in activated Th cells. In naive Th cells, Ets-2 mRNA expression, Ets-2 protein levels, and Ets-2 binding to ARRE-2 decrease upon cell activation followed by the concomitant expression of IL-2. Cyclosporine A stabilizes Ets-2 mRNA and protein when the cells are activated. Ets-2 silences directly constitutive or induced IL-2 expression through the ARRE-2. Conversely, Ets-2 silencing allows for constitutive IL-2 expression in unstimulated cells. Ets-2 binding to ARRE-2 in chromatin is stronger in naive compared with activated or memory Th cells; in the latter, Ets-2 participates in a change of the IL-2 promoter architecture, possibly to facilitate a quick response when the cells re-encounter antigen. We propose that Ets-2 expression and protein binding to the ARRE-2 of the IL-2 promoter are part of a strictly regulated process that results in a physiological transition of naive Th cells to Th0 cells upon antigenic stimulation. Malfunction of such a repression mechanism at the molecular level could lead to a disturbance of later events in Th cell plasticity, leading to autoimmune diseases or other pathological conditions. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  13. Transcriptional repressor role of PocR on the 1,3-propanediol biosynthetic pathway by Lactobacillus panis PM1.

    Science.gov (United States)

    Kang, Tae Sun; Korber, Darren R; Tanaka, Takuji

    2014-06-01

    The regulatory role of a transcriptional regulator (PocR) in the 1,3-propanediol biosynthetic pathway of Lactobacillus panis PM1 contributes to the optimization of 1,3-propanediol production by this strain, which potentially will lead to 1,3-propanediol manufacturing efficiencies. Lactobacillus panis PM1 can utilize a 1,3-propanediol (1,3-PDO) biosynthetic pathway, consisting of diol dehydratase (PduCDE) and 1,3-PDO dehydrogenase, as a NADH recycling system, to survive under various environmental conditions. In this study, we identified a key transcriptional repressor (PocR) which was annotated as a transcriptional factor of AraC family as part of the 1,3-PDO biosynthetic pathway of L. panis PM1. The over-expression of the PocR gene resulted in the significant repression (81 %) of pduC (PduCDE large subunit) transcription, and subsequently, the decreased activity of PduCDE by 22 %. As a result of the regulation of PduCDE, production of both 3-hydroxypropionaldehyde and 1,3-PDO in the PocR over-expressing strain were significantly decreased by 40 % relative to the control strain. These results clearly demonstrate the transcriptional repressor role of PocR in the 1,3-PDO biosynthetic pathway.

  14. Specific defects in different transcription complexes compensate for the requirement of the negative cofactor 2 repressor in Saccharomyces cerevisiae.

    Science.gov (United States)

    Peiró-Chova, Lorena; Estruch, Francisco

    2007-05-01

    Negative cofactor 2 (NC2) has been described as an essential and evolutionarily conserved transcriptional repressor, although in vitro and in vivo experiments suggest that it can function as both a positive and a negative effector of transcription. NC2 operates by interacting with the core promoter and components of the basal transcription machinery, like the TATA-binding protein (TBP). In this work, we have isolated mutants that suppress the growth defect caused by the depletion of NC2. We have identified mutations affecting components of three different complexes involved in the control of basal transcription: the mediator, TFIIH, and RNA pol II itself. Mutations in RNA pol II include both overexpression of truncated forms of the two largest subunits (Rpb1 and Rpb2) and reduced levels of these proteins. Suppression of NC2 depletion was also observed by reducing the amounts of the mediator essential components Nut2 and Med7, as well as by deleting any of the nonessential mediator components, except Med2, Med3, and Gal11 subunits. Interestingly, the Med2/Med3/Gal11 triad forms a submodule within the mediator tail. Our results support the existence of different components within the basic transcription complexes that antagonistically interact with the NC2 repressor and suggest that the correct balance between the activities of specific positive and negative components is essential for cell growth.

  15. PIAS proteins are involved in the SUMO-1 modification, intracellular translocation and transcriptional repressive activity of RET finger protein

    International Nuclear Information System (INIS)

    Matsuura, Tetsuo; Shimono, Yohei; Kawai, Kumi; Murakami, Hideki; Urano, Takeshi; Niwa, Yasumasa; Goto, Hidemi; Takahashi, Masahide

    2005-01-01

    Ret finger protein (RFP) is a nuclear protein that is highly expressed in testis and in various tumor cell lines. RFP functions as a transcriptional repressor and associates with Enhancer of Polycomb 1 (EPC1), a member of the Polycomb group proteins, and Mi-2β, a main component of the nucleosome remodeling and deacetylase (NuRD) complex. We show that RFP binds with PIAS (protein inhibitor of activated STAT) proteins, PIAS1, PIAS3, PIASxα and PIASy at their carboxyl-terminal region and is covalently modified by SUMO-1 (sumoylation). PIAS proteins enhance the sumoylation of RFP in a dose-dependent manner and induce the translocation of RFP into nuclear bodies reminiscent of the PML bodies. In addition, co-expression of PIAS proteins or SUMO-1 strengthened the transcriptional repressive activity of RFP. Finally, our immunohistochemical results show that RFP, SUMO-1 and PIASy localize in a characteristic nuclear structure juxtaposed with the inner nuclear membrane (XY body) of primary spermatocytes in mouse testis. These results demonstrate that the intracellular location and the transcriptional activity of RFP are modified by PIAS proteins which possess SUMO E3 ligase activities and suggest that they may play a co-operative role in spermatogenesis

  16. The ZEB1 transcription factor is a novel repressor of adiposity in female mice.

    Directory of Open Access Journals (Sweden)

    Jessica N Saykally

    Full Text Available BACKGROUND: Four genome-wide association studies mapped an "obesity" gene to human chromosome 10p11-12. As the zinc finger E-box binding homeobox 1 (ZEB1 transcription factor is encoded by the TCF8 gene located in that region, and as it influences the differentiation of various mesodermal lineages, we hypothesized that ZEB1 might also modulate adiposity. The goal of these studies was to test that hypothesis in mice. METHODOLOGY/PRINCIPAL FINDINGS: To ascertain whether fat accumulation affects ZEB1 expression, female C57BL/6 mice were fed a regular chow diet (RCD ad libitum or a 25% calorie-restricted diet from 2.5 to 18.3 months of age. ZEB1 mRNA levels in parametrial fat were six to ten times higher in the obese mice. To determine directly whether ZEB1 affects adiposity, wild type (WT mice and mice heterozygous for TCF8 (TCF8+/- were fed an RCD or a high-fat diet (HFD (60% calories from fat. By two months of age on an HFD and three months on an RCD, TCF8+/- mice were heavier than WT controls, which was attributed by Echo MRI to increased fat mass (at three months on an HFD: 0.517+/-0.081 total fat/lean mass versus 0.313+/-0.036; at three months on an RCD: 0.175+/-0.013 versus 0.124+/-0.012. No differences were observed in food uptake or physical activity, suggesting that the genotypes differ in some aspect of their metabolic activity. ZEB1 expression also increases during adipogenesis in cell culture. CONCLUSION/SIGNIFICANCE: These results show for the first time that the ZEB1 transcription factor regulates the accumulation of adipose tissue. Furthermore, they corroborate the genome-wide association studies that mapped an "obesity" gene at chromosome 10p11-12.

  17. Proline dehydrogenase activity of the transcriptional repressor PutA is required for induction of the put operon by proline.

    Science.gov (United States)

    Muro-Pastor, A M; Maloy, S

    1995-04-28

    The proline utilization (put) operon from Salmonella typhimurium consists of the putP gene, encoding a proline transporter, and the putA gene, encoding an enzyme with both proline dehydrogenase and 1-pyrroline-5-carboxylate dehydrogenase activities. In addition to these two enzymatic activities, the PutA protein is a transcriptional repressor that regulates the expression of putP and putA in response to the availability of proline. We report the isolation of super-repressor mutants of PutA that decrease expression from the putA promoter in the presence or absence of proline. None of the mutants exhibited increased affinity for the DNA in the put regulatory region in vitro. Although DNA binding by wild-type PutA was prevented by the addition of proline and an artificial electron acceptor, DNA binding by the two strongest super-repressors was not prevented under identical conditions. The proline dehydrogenase activity of the purified mutant proteins showed altered kinetic properties (increased Km(Pro), reduced Vmax, or a completely null phenotype). The observation that these mutations simultaneously affect induction by proline and proline dehydrogenase activity suggests that a single proline-binding site is involved in both proline dehydrogenase activity and induction of the expression of the put operon. Furthermore, the results indicate that the proline dehydrogenase activity of PutA is essential for induction of the put operon by proline.

  18. The Banana Transcriptional Repressor MaDEAR1 Negatively Regulates Cell Wall-Modifying Genes Involved in Fruit Ripening.

    Science.gov (United States)

    Fan, Zhong-Qi; Kuang, Jian-Fei; Fu, Chang-Chun; Shan, Wei; Han, Yan-Chao; Xiao, Yun-Yi; Ye, Yu-Jie; Lu, Wang-Jin; Lakshmanan, Prakash; Duan, Xue-Wu; Chen, Jian-Ye

    2016-01-01

    Ethylene plays an essential role in many biological processes including fruit ripening via modulation of ethylene signaling pathway. Ethylene Response Factors (ERFs) are key transcription factors (TFs) involved in ethylene perception and are divided into AP2, RAV, ERF, and DREB sub-families. Although a number of studies have implicated the involvement of DREB sub-family genes in stress responses, little is known about their roles in fruit ripening. In this study, we identified a DREB TF with a EAR motif, designated as MaDEAR1, which is a nucleus-localized transcriptional repressor. Expression analysis indicated that MaDEAR1 expression was repressed by ethylene, with reduced levels of histone H3 and H4 acetylation at its regulatory regions during fruit ripening. In addition, MaDEAR1 promoter activity was also suppressed in response to ethylene treatment. More importantly, MaDEAR1 directly binds to the DRE/CRT motifs in promoters of several cell wall-modifying genes including MaEXP1/3, MaPG1, MaXTH10, MaPL3, and MaPME3 associated with fruit softening during ripening and represses their activities. These data suggest that MaDEAR1 acts as a transcriptional repressor of cell wall-modifying genes, and may be negatively involved in ethylene-mediated ripening of banana fruit. Our findings provide new insights into the involvement of DREB TFs in the regulation of fruit ripening.

  19. Silencing the Transcriptional Repressor, ZCT1, Illustrates the Tight Regulation of Terpenoid Indole Alkaloid Biosynthesis in Catharanthus roseus Hairy Roots.

    Directory of Open Access Journals (Sweden)

    Noreen F Rizvi

    Full Text Available The Catharanthus roseus plant is the source of many valuable terpenoid indole alkaloids (TIAs, including the anticancer compounds vinblastine and vincristine. Transcription factors (TFs are promising metabolic engineering targets due to their ability to regulate multiple biosynthetic pathway genes. To increase TIA biosynthesis, we elicited the TIA transcriptional activators (ORCAs and other unidentified TFs with the plant hormone, methyl jasmonate (MJ, while simultaneously silencing the expression of the transcriptional repressor ZCT1. To silence ZCT1, we developed transgenic hairy root cultures of C. roseus that expressed an estrogen-inducible Zct1 hairpin for activating RNA interference. The presence of 17β-estradiol (5μM effectively depleted Zct1 in hairy root cultures elicited with MJ dosages that either optimize or inhibit TIA production (250 or 1000μM. However, silencing Zct1 was not sufficient to increase TIA production or the expression of the TIA biosynthetic genes (G10h, Tdc, and Str, illustrating the tight regulation of TIA biosynthesis. The repression of the TIA biosynthetic genes at the inhibitory MJ dosage does not appear to be solely regulated by ZCT1. For instance, while Zct1 and Zct2 levels decreased through activating the Zct1 hairpin, Zct3 levels remained elevated. Since ZCT repressors have redundant yet distinct functions, silencing all three ZCTs may be necessary to relieve their repression of alkaloid biosynthesis.

  20. The banana transcriptional repressor MaDEAR1 negatively regulates cell wall-modifying genes involved in fruit ripening

    Directory of Open Access Journals (Sweden)

    Zhong-qi Fan

    2016-07-01

    Full Text Available Ethylene plays an essential role in many biological processes including fruit ripening via modulation of ethylene signaling pathway. Ethylene Response Factors (ERFs are key transcription factors (TFs involved in ethylene perception and are divided into AP2, RAV, ERF and DREB sub-families. Although a number of studies have implicated the involvement of DREB sub-family genes in stress responses, little is known about their roles in fruit ripening. In this study, we identified a DREB TF with a EAR motif, designated as MaDEAR1, which is a nucleus-localized transcriptional repressor. Expression analysis indicated that MaDEAR1 expression was repressed by ethylene, with reduced levels of histone H3 and H4 acetylation at its regulatory regions during fruit ripening. In addition, MaDEAR1 promoter activity was also suppressed in response to ethylene treatment. More importantly, MaDEAR1 directly binds to the DRE/CRT motifs in promoters of several cell wall-modifying genes including MaEXP1/3, MaPG1, MaXTH10, MaPL3 and MaPME3 associated with fruit softening during ripening and represses their activities. These data suggest that MaDEAR1 acts as a transcriptional repressor of cell wall-modifying genes, and may be negatively involved in ethylene-mediated ripening of banana fruit. Our findings provide new insights into the involvement of DREB TFs in the regulation of fruit ripening.

  1. Small Ubiquitin-like Modifier (SUMO) Conjugation Impedes Transcriptional Silencing by the Polycomb Group Repressor Sex Comb on Midleg*

    OpenAIRE

    Smith, Matthew; Mallin, Daniel R.; Simon, Jeffrey A.; Courey, Albert J.

    2011-01-01

    The Drosophila protein Sex Comb on Midleg (Scm) is a member of the Polycomb group (PcG), a set of transcriptional repressors that maintain silencing of homeotic genes during development. Recent findings have identified PcG proteins both as targets for modification by the small ubiquitin-like modifier (SUMO) protein and as catalytic components of the SUMO conjugation pathway. We have found that the SUMO-conjugating enzyme Ubc9 binds to Scm and that this interaction, which requires the Scm C-te...

  2. The Groucho co-repressor is primarily recruited to local target sites in active chromatin to attenuate transcription.

    Directory of Open Access Journals (Sweden)

    Aamna Kaul

    2014-08-01

    Full Text Available Gene expression is regulated by the complex interaction between transcriptional activators and repressors, which function in part by recruiting histone-modifying enzymes to control accessibility of DNA to RNA polymerase. The evolutionarily conserved family of Groucho/Transducin-Like Enhancer of split (Gro/TLE proteins act as co-repressors for numerous transcription factors. Gro/TLE proteins act in several key pathways during development (including Notch and Wnt signaling, and are implicated in the pathogenesis of several human cancers. Gro/TLE proteins form oligomers and it has been proposed that their ability to exert long-range repression on target genes involves oligomerization over broad regions of chromatin. However, analysis of an endogenous gro mutation in Drosophila revealed that oligomerization of Gro is not always obligatory for repression in vivo. We have used chromatin immunoprecipitation followed by DNA sequencing (ChIP-seq to profile Gro recruitment in two Drosophila cell lines. We find that Gro predominantly binds at discrete peaks (<1 kilobase. We also demonstrate that blocking Gro oligomerization does not reduce peak width as would be expected if Gro oligomerization induced spreading along the chromatin from the site of recruitment. Gro recruitment is enriched in "active" chromatin containing developmentally regulated genes. However, Gro binding is associated with local regions containing hypoacetylated histones H3 and H4, which is indicative of chromatin that is not fully open for efficient transcription. We also find that peaks of Gro binding frequently overlap the transcription start sites of expressed genes that exhibit strong RNA polymerase pausing and that depletion of Gro leads to release of polymerase pausing and increased transcription at a bona fide target gene. Our results demonstrate that Gro is recruited to local sites by transcription factors to attenuate rather than silence gene expression by promoting histone

  3. NF-Y recruits both transcription activator and repressor to modulate tissue- and developmental stage-specific expression of human γ-globin gene.

    Directory of Open Access Journals (Sweden)

    Xingguo Zhu

    Full Text Available The human embryonic, fetal and adult β-like globin genes provide a paradigm for tissue- and developmental stage-specific gene regulation. The fetal γ-globin gene is expressed in fetal erythroid cells but is repressed in adult erythroid cells. The molecular mechanism underlying this transcriptional switch during erythroid development is not completely understood. Here, we used a combination of in vitro and in vivo assays to dissect the molecular assemblies of the active and the repressed proximal γ-globin promoter complexes in K562 human erythroleukemia cell line and primary human fetal and adult erythroid cells. We found that the proximal γ-globin promoter complex is assembled by a developmentally regulated, general transcription activator NF-Y bound strongly at the tandem CCAAT motifs near the TATA box. NF-Y recruits to neighboring DNA motifs the developmentally regulated, erythroid transcription activator GATA-2 and general repressor BCL11A, which in turn recruit erythroid repressor GATA-1 and general repressor COUP-TFII to form respectively the NF-Y/GATA-2 transcription activator hub and the BCL11A/COUP-TFII/GATA-1 transcription repressor hub. Both the activator and the repressor hubs are present in both the active and the repressed γ-globin promoter complexes in fetal and adult erythroid cells. Through changes in their levels and respective interactions with the co-activators and co-repressors during erythroid development, the activator and the repressor hubs modulate erythroid- and developmental stage-specific transcription of γ-globin gene.

  4. The transcription repressors Bach2 and Bach1 promote B cell development by repressing the myeloid program.

    Science.gov (United States)

    Itoh-Nakadai, Ari; Hikota, Reina; Muto, Akihiko; Kometani, Kohei; Watanabe-Matsui, Miki; Sato, Yuki; Kobayashi, Masahiro; Nakamura, Atsushi; Miura, Yuichi; Yano, Yoko; Tashiro, Satoshi; Sun, Jiying; Ikawa, Tomokatsu; Ochiai, Kyoko; Kurosaki, Tomohiro; Igarashi, Kazuhiko

    2014-12-01

    Mature lymphoid cells express the transcription repressor Bach2, which imposes regulation on humoral and cellular immunity. Here we found critical roles for Bach2 in the development of cells of the B lineage, commencing from the common lymphoid progenitor (CLP) stage, with Bach1 as an auxiliary. Overexpression of Bach2 in pre-pro-B cells deficient in the transcription factor EBF1 and single-cell analysis of CLPs revealed that Bach2 and Bach1 repressed the expression of genes important for myeloid cells ('myeloid genes'). Bach2 and Bach1 bound to presumptive regulatory regions of the myeloid genes. Bach2(hi) CLPs showed resistance to myeloid differentiation even when cultured under myeloid conditions. Our results suggest that Bach2 functions with Bach1 and EBF1 to promote B cell development by repressing myeloid genes in CLPs.

  5. FOXP3 is a novel transcriptional repressor for the breast cancer oncogene SKP2

    OpenAIRE

    Zuo, Tao; Liu, Runhua; Zhang, Huiming; Chang, Xing; Liu, Yan; Wang, Lizhong; Zheng, Pan; Liu, Yang

    2007-01-01

    S-phase kinase-associated protein 2 (SKP2) is a component of the E3 ubiquitin ligase SKP1-Cul1-Fbox complex. Overexpression of SKP2 results in cell cycle dysregulation and carcinogenesis; however, the genetic lesions that cause this upregulation are poorly understood. We recently demonstrated that forkhead box P3 (FOXP3) is an X-linked breast cancer suppressor and an important repressor of the oncogene ERBB2/HER2. Since FOXP3 suppresses tumor growth regardless of whether the tumors overexpres...

  6. The general transcriptional repressor Tup1 is required for dimorphism and virulence in a fungal plant pathogen.

    Directory of Open Access Journals (Sweden)

    Alberto Elías-Villalobos

    2011-09-01

    Full Text Available A critical step in the life cycle of many fungal pathogens is the transition between yeast-like growth and the formation of filamentous structures, a process known as dimorphism. This morphological shift, typically triggered by multiple environmental signals, is tightly controlled by complex genetic pathways to ensure successful pathogenic development. In animal pathogenic fungi, one of the best known regulators of dimorphism is the general transcriptional repressor, Tup1. However, the role of Tup1 in fungal dimorphism is completely unknown in plant pathogens. Here we show that Tup1 plays a key role in orchestrating the yeast to hypha transition in the maize pathogen Ustilago maydis. Deletion of the tup1 gene causes a drastic reduction in the mating and filamentation capacity of the fungus, in turn leading to a reduced virulence phenotype. In U. maydis, these processes are controlled by the a and b mating-type loci, whose expression depends on the Prf1 transcription factor. Interestingly, Δtup1 strains show a critical reduction in the expression of prf1 and that of Prf1 target genes at both loci. Moreover, we observed that Tup1 appears to regulate Prf1 activity by controlling the expression of the prf1 transcriptional activators, rop1 and hap2. Additionally, we describe a putative novel prf1 repressor, named Pac2, which seems to be an important target of Tup1 in the control of dimorphism and virulence. Furthermore, we show that Tup1 is required for full pathogenic development since tup1 deletion mutants are unable to complete the sexual cycle. Our findings establish Tup1 as a key factor coordinating dimorphism in the phytopathogen U. maydis and support a conserved role for Tup1 in the control of hypha-specific genes among animal and plant fungal pathogens.

  7. Transcriptional repressor domain of MBD1 is intrinsically disordered and interacts with its binding partners in a selective manner.

    KAUST Repository

    Hameed, Umar Farook Shahul

    2014-05-09

    Methylation of DNA CpG sites is a major mechanism of epigenetic gene silencing and plays important roles in cell division, development and carcinogenesis. One of its regulators is the 64-residue C-terminal Transcriptional Repressor Domain (the TRD) of MBD1, which recruits several repressor proteins such as MCAF1, HDAC3 and MPG that are essential for the gene silencing. Using NMR spectroscopy, we have characterized the solution structure of the C-terminus of MBD1 (MBD1-c, residues D507 to Q605), which included the TRD (A529 to P592). Surprisingly, the MBD1-c is intrinsically disordered. Despite its lack of a tertiary folding, MBD1-c could still bind to different partner proteins in a selective manner. MPG and MCAF1Δ8 showed binding to both the N-terminal and C-terminal residues of MBD1-c but HDAC3 preferably bound to the C-terminal region. This study reveals how MBD1-c discriminates different binding partners, and thus, expands our understanding of the mechanisms of gene regulation by MBD1.

  8. The Nuclear Factor of Activated T Cells (Nfat) Transcription Factor Nfatp (Nfatc2) Is a Repressor of Chondrogenesis

    Science.gov (United States)

    Ranger, Ann M.; Gerstenfeld, Louis C.; Wang, Jinxi; Kon, Tamiyo; Bae, Hyunsu; Gravallese, Ellen M.; Glimcher, Melvin J.; Glimcher, Laurie H.

    2000-01-01

    Nuclear factor of activated T cells (NFAT) transcription factors regulate gene expression in lymphocytes and control cardiac valve formation. Here, we report that NFATp regulates chondrogenesis in the adult animal. In mice lacking NFATp, resident cells in the extraarticular connective tissues spontaneously differentiate to cartilage. These cartilage cells progressively differentiate and the tissue undergoes endochondral ossification, recapitulating the development of endochondral bone. Proliferation of already existing articular cartilage cells also occurs in some older animals. At both sites, neoplastic changes in the cartilage cells occur. Consistent with these data, NFATp expression is regulated in mesenchymal stem cells induced to differentiate along a chondrogenic pathway. Lack of NFATp in articular cartilage cells results in increased expression of cartilage markers, whereas overexpression of NFATp in cartilage cell lines extinguishes the cartilage phenotype. Thus, NFATp is a repressor of cartilage cell growth and differentiation and also has the properties of a tumor suppressor. PMID:10620601

  9. Zinc finger protein 521 overexpression increased transcript levels of ...

    Indian Academy of Sciences (India)

    2016-02-12

    Feb 12, 2016 ... Zfp521 enhanced transcription levels of both EGFP and endogenous Fndc5. This result was confirmed by overexpression the aforementioned vectors in HEK cells and indicated that Zfp521 functions upstream of Fndc5 expression. It is most likely that Zfp521 may act through the binding to its response ...

  10. Tcf7l2/Tcf4 Transcriptional Repressor Function Requires HDAC Activity in the Developing Vertebrate CNS.

    Directory of Open Access Journals (Sweden)

    Hui Wang

    Full Text Available The generation of functionally distinct neuronal subtypes within the vertebrate central nervous system (CNS requires the precise regulation of progenitor gene expression in specific neuronal territories during early embryogenesis. Accumulating evidence has implicated histone deacetylase (HDAC proteins in cell specification, proliferation, and differentiation in diverse embryonic and adult tissues. However, although HDAC proteins have shown to be expressed in the developing vertebrate neural tube, their specific role in CNS neural progenitor fate specification remains unclear. Prior work from our lab showed that the Tcf7l2/Tcf4 transcription factor plays a key role in ventral progenitor lineage segregation by differential repression of two key specification factors, Nkx2.2 and Olig2. In this study, we found that administration of HDAC inhibitors (Valproic Acid (VPA, Trichostatin-A (TSA, or sodium butyrate in chick embryos in ovo disrupted normal progenitor gene segregation in the developing neural tube, indicating that HDAC activity is required for this process. Further, using functional and pharmacological approaches in vivo, we found that HDAC activity is required for the differential repression of Nkx2.2 and Olig2 by Tcf7l2/Tcf4. Finally, using dominant-negative functional assays, we provide evidence that Tcf7l2/Tcf4 repression also requires Gro/TLE/Grg co-repressor factors. Together, our data support a model where the transcriptional repressor activity of Tcf7l2/Tcf4 involves functional interactions with both HDAC and Gro/TLE/Grg co-factors at specific target gene regulatory elements in the developing neural tube, and that this activity is required for the proper segregation of the Nkx2.2 (p3 and Olig2 (pMN expressing cells from a common progenitor pool.

  11. Haploinsufficiency of MeCP2-interacting transcriptional co-repressor SIN3A causes mild intellectual disability by affecting the development of cortical integrity

    NARCIS (Netherlands)

    Witteveen, Josefine S.; Willemsen, Marjolein H.; Dombroski, Thais C. D.; van Bakel, Nick H. M.; Nillesen, Willy M.; van Hulten, Josephus A.; Jansen, Eric J. R.; Verkaik, Dave; Veenstra-Knol, Hermine E.; van Ravenswaaij-Arts, Conny M. A.; Wassink-Ruiter, Jolien S. Klein; Vincent, Marie; David, Albert; Le Caignec, Cedric; Schieving, Jolanda; Gilissen, Christian; Foulds, Nicola; Rump, Patrick; Strom, Tim; Cremer, Kirsten; Zink, Alexander M.; Engels, Hartmut; de Munnik, Sonja A.; Visser, Jasper E.; Brunner, Han G.; Martens, Gerard J. M.; Pfundt, Rolph; Kleefstra, Tjitske; Kolk, Sharon M.

    Numerous genes are associated with neurodevelopmental disorders such as intellectual disability and autism spectrum disorder ( ASD), but their dysfunction is often poorly characterized. Here we identified dominant mutations in the gene encoding the transcriptional repressor and MeCP2 interactor

  12. Haploinsufficiency of MeCP2-interacting transcriptional co-repressor SIN3A causes mild intellectual disability by affecting the development of cortical integrity

    NARCIS (Netherlands)

    Witteveen, J.S.; Willemsen, M.H.; Dombroski, T.C.; Bakel, N.H. van; Nillesen, W.M.; Hulten, J.A. van; Jansen, E.J.; Verkaik, D.; Veenstra-Knol, H.E.; Ravenswaaij-Arts, C.M.A. van; Wassink-Ruiter, J.S.; Vincent, M.; David, A.; Le Caignec, C.; Schieving, J.; Gilissen, C.; Foulds, N.; Rump, P.; Strom, T.; Cremer, K.; Zink, A.M.; Engels, H.; Munnik, S.A. de; Visser, J.E.; Brunner, H.G.; Martens, G.J.; Pfundt, R.P.; Kleefstra, T.; Kolk, S.M.

    2016-01-01

    Numerous genes are associated with neurodevelopmental disorders such as intellectual disability and autism spectrum disorder (ASD), but their dysfunction is often poorly characterized. Here we identified dominant mutations in the gene encoding the transcriptional repressor and MeCP2 interactor

  13. Proto-oncogene FBI-1 (Pokemon/ZBTB7A) Represses Transcription of the Tumor Suppressor Rb Gene via Binding Competition with Sp1 and Recruitment of Co-repressors*S⃞

    Science.gov (United States)

    Jeon, Bu-Nam; Yoo, Jung-Yoon; Choi, Won-Il; Lee, Choong-Eun; Yoon, Ho-Geun; Hur, Man-Wook

    2008-01-01

    FBI-1 (also called Pokemon/ZBTB7A) is a BTB/POZ-domain Krüppel-like zinc-finger transcription factor. Recently, FBI-1 was characterized as a proto-oncogenic protein, which represses tumor suppressor ARF gene transcription. The expression of FBI-1 is increased in many cancer tissues. We found that FBI-1 potently represses transcription of the Rb gene, a tumor suppressor gene important in cell cycle arrest. FBI-1 binds to four GC-rich promoter elements (FREs) located at bp –308 to –188 of the Rb promoter region. The Rb promoter also contains two Sp1 binding sites: GC-box 1 (bp –65 to –56) and GC-box 2 (bp –18 to –9), the latter of which is also bound by FBI-1. We found that FRE3 (bp –244 to –236) is also a Sp1 binding element. FBI-1 represses transcription of the Rb gene not only by binding to the FREs, but also by competing with Sp1 at the GC-box 2 and the FRE3. By binding to the FREs and/or the GC-box, FBI-1 represses transcription of the Rb gene through its POZ-domain, which recruits a co-repressor-histone deacetylase complex and deacetylates histones H3 and H4 at the Rb gene promoter. FBI-1 inhibits C2C12 myoblast cell differentiation by repressing Rb gene expression. PMID:18801742

  14. The MogR Transcriptional Repressor Regulates Nonhierarchal Expression of Flagellar Motility Genes and Virulence in Listeria monocytogenes.

    Directory of Open Access Journals (Sweden)

    2006-04-01

    Full Text Available Flagella are surface structures critical for motility and virulence of many bacterial species. In Listeria monocytogenes, MogR tightly represses expression of flagellin (FlaA during extracellular growth at 37 degrees C and during intracellular infection. MogR is also required for full virulence in a murine model of infection. Using in vitro and in vivo infection models, we determined that the severe virulence defect of MogR-negative bacteria is due to overexpression of FlaA. Specifically, overproduction of FlaA in MogR-negative bacteria caused pleiotropic defects in bacterial division (chaining phenotype, intracellular spread, and virulence in mice. DNA binding and microarray analyses revealed that MogR represses transcription of all known flagellar motility genes by binding directly to a minimum of two TTTT-N(5-AAAA recognition sites positioned within promoter regions such that RNA polymerase binding is occluded. Analysis of MogR protein levels demonstrated that modulation of MogR repression activity confers the temperature-specificity to flagellar motility gene expression. Epistasis analysis revealed that MogR repression of transcription is antagonized in a temperature-dependent manner by the DegU response regulator and that DegU further regulates FlaA levels through a posttranscriptional mechanism. These studies provide the first known example to our knowledge of a transcriptional repressor functioning as a master regulator controlling nonhierarchal expression of flagellar motility genes.

  15. Insights into structural and functional diversity of Dof (DNA binding with one finger) transcription factor.

    Science.gov (United States)

    Gupta, S; Malviya, N; Kushwaha, H; Nasim, J; Bisht, N C; Singh, V K; Yadav, D

    2015-03-01

    The structural, functional and in-silico studies of Dof transcription factor attempted so far reveals immense opportunity to analyze the plant genomes in terms of number of Dof genes and discuss in light of the evolution. The multiple functions of Dof genes needs to explored for crop improvement. Transcription factors play a very vital role in gene regulation at transcriptional level and are being extensively studied across phylas. In recent years, sequencing of plant genomes has led to genome-wide identification and characterizations of diverse types of plant-specific transcription factor gene family providing key insights into their structural and functional diversity. The DNA binding with one finger (Dof), a class belonging to C2H2-type zinc finger family proteins, is a plant-specific transcription factor having multiple roles such as seed maturation and germination, phytohormone and light-mediated regulation and plant responses to biotic and abiotic stresses. Dof proteins are present across plant lineage, from green algae to higher angiosperm, and represent a unique class of transcription factor having bifunctional binding activities, with both DNA and proteins, to regulate the complex transcriptional machinery in plant cells. The structural and functional diversity of the Dof transcription factor family along with the bioinformatics analysis highlighting the phylogeny of Dof families is reviewed in light of its importance in plant biotechnology for crop improvement.

  16. Arabidopsis thaliana VOZ (Vascular plant One-Zinc finger) transcription factors are required for proper regulation of flowering time.

    Science.gov (United States)

    Celesnik, Helena; Ali, Gul S; Robison, Faith M; Reddy, Anireddy S N

    2013-04-15

    Transition to flowering in plants is tightly controlled by environmental cues, which regulate the photoperiod and vernalization pathways, and endogenous signals, which mediate the autonomous and gibberellin pathways. In this work, we investigated the role of two Zn(2+)-finger transcription factors, the paralogues AtVOZ1 and AtVOZ2, in Arabidopsis thaliana flowering. Single atvoz1-1 and atvoz2-1 mutants showed no significant phenotypes as compared to wild type. However, atvoz1-1 atvoz2-1 double mutant plants exhibited several phenotypes characteristic of flowering-time mutants. The double mutant displayed a severe delay in flowering, together with additional pleiotropic phenotypes. Late flowering correlated with elevated expression of FLOWERING LOCUS C (FLC), which encodes a potent floral repressor, and decreased expression of its target, the floral promoter FD. Vernalization rescued delayed flowering of atvoz1-1 atvoz2-1 and reversed elevated FLC levels. Accumulation of FLC transcripts in atvoz1-1 atvoz2-1 correlated with increased expression of several FLC activators, including components of the PAF1 and SWR1 chromatin-modifying complexes. Additionally, AtVOZs were shown to bind the promoter of MOS3/SAR3 and directly regulate expression of this nuclear pore protein, which is known to participate in the regulation of flowering time, suggesting that AtVOZs exert at least some of their flowering regulation by influencing the nuclear pore function. Complementation of atvoz1-1 atvoz2-1 with AtVOZ2 reversed all double mutant phenotypes, confirming that the observed morphological and molecular changes arise from the absence of functional AtVOZ proteins, and validating the functional redundancy between AtVOZ1 and AtVOZ2.

  17. The Transcriptional Repressor MYB2 Regulates Both Spatial and Temporal Patterns of Proanthocyandin and Anthocyanin Pigmentation in Medicago truncatula.

    Science.gov (United States)

    Jun, Ji Hyung; Liu, Chenggang; Xiao, Xirong; Dixon, Richard A

    2015-10-01

    Accumulation of anthocyanins and proanthocyanidins (PAs) is limited to specific cell types and developmental stages, but little is known about how antagonistically acting transcriptional regulators work together to determine temporal and spatial patterning of pigmentation at the cellular level, especially for PAs. Here, we characterize MYB2, a transcriptional repressor regulating both anthocyanin and PA biosynthesis in the model legume Medicago truncatula. MYB2 was strongly upregulated by MYB5, a major regulator of PA biosynthesis in M. truncatula and a component of MYB-basic helix loop helix-WD40 (MBW) activator complexes. Overexpression of MYB2 abolished anthocyanin and PA accumulation in M. truncatula hairy roots and Arabidopsis thaliana seeds, respectively. Anthocyanin deposition was expanded in myb2 mutant seedlings and flowers accompanied by increased anthocyanin content. PA mainly accumulated in the epidermal layer derived from the outer integument in the M. truncatula seed coat, starting from the hilum area. The area of PA accumulation and ANTHOCYANIDIN REDUCTASE expression was expanded into the seed body at the early stage of seed development in the myb2 mutant. Genetic, biochemical, and cell biological evidence suggests that MYB2 functions as part of a multidimensional regulatory network to define the temporal and spatial pattern of anthocyanin and PA accumulation linked to developmental processes. © 2015 American Society of Plant Biologists. All rights reserved.

  18. Elk3 from hamster-a ternary complex factor with strong transcriptional repressor activity

    DEFF Research Database (Denmark)

    Hjortoe, G.M.; Weilguny, D.; Willumsen, Berthe Marie

    2005-01-01

    the transcription of genes that are activated during entry into G1. We have isolated the Cricetulus griseus Elk3 gene from the Chinese hamster ovary (CHO) cell line and investigated the transcriptional potential of this factor. Transient transfections revealed that, in addition to its regulation of the c......-fos promoter, Elk3 from CHO cells seems to inhibit other promoters controlling expression of proteins involved in G1/S phase progression; Cyclin D1 and DHFR. As has been described for the Elk3 homologs Net (Mouse) and Sap-2 (Human), the results of the present study further indicate that hamster Elk3...

  19. The LIM homeodomain transcription factor LHX6: a transcriptional repressor that interacts with pituitary homeobox 2 (PITX2) to regulate odontogenesis.

    Science.gov (United States)

    Zhang, Zichao; Gutierrez, Diana; Li, Xiao; Bidlack, Felicitas; Cao, Huojun; Wang, Jianbo; Andrade, Kelsey; Margolis, Henry C; Amendt, Brad A

    2013-01-25

    LHX6 is a LIM-homeobox transcription factor expressed during embryogenesis; however, the molecular mechanisms regulating LHX6 transcriptional activities are unknown. LHX6 and the PITX2 homeodomain transcription factor have overlapping expression patterns during tooth and craniofacial development, and in this report, we demonstrate new transcriptional mechanisms for these factors. PITX2 and LHX6 are co-expressed in the oral and dental epithelium and epithelial cell lines. Lhx6 expression is increased in Pitx2c transgenic mice and decreased in Pitx2 null mice. PITX2 activates endogenous Lhx6 expression and the Lhx6 promoter, whereas LHX6 represses its promoter activity. Chromatin immunoprecipitation experiments reveal endogenous PITX2 binding to the Lhx6 promoter. LHX6 directly interacts with PITX2 to inhibit PITX2 transcriptional activities and activation of multiple promoters. Bimolecular fluorescence complementation assays reveal an LHX6·PITX2 nuclear interaction in living cells. LHX6 has a dominant repressive effect on the PITX2 synergistic activation with LEF-1 and β-catenin co-factors. Thus, LHX6 acts as a transcriptional repressor and represses the expression of several genes involved in odontogenesis. We have identified specific defects in incisor, molar, mandible, bone, and root development and late stage enamel formation in Lhx6 null mice. Amelogenin and ameloblastin expression is reduced and/or delayed in the Lhx6 null mice, potentially resulting from defects in dentin deposition and ameloblast differentiation. Our results demonstrate that LHX6 regulates cell proliferation in the cervical loop and promotes cell differentiation in the anterior region of the incisor. We demonstrate new molecular mechanisms for LHX6 and an interaction with PITX2 for normal craniofacial and tooth development.

  20. The leukemia associated ETO nuclear repressor gene is regulated by the GATA-1 transcription factor in erythroid/megakaryocytic cells

    Directory of Open Access Journals (Sweden)

    Gullberg Urban

    2010-05-01

    Full Text Available Abstract Background The Eight-Twenty-One (ETO nuclear co-repressor gene belongs to the ETO homologue family also containing Myeloid Translocation Gene on chromosome 16 (MTG16 and myeloid translocation Gene-Related protein 1 (MTGR1. By chromosomal translocations ETO and MTG16 become parts of fusion proteins characteristic of morphological variants of acute myeloid leukemia. Normal functions of ETO homologues have as yet not been examined. The goal of this work was to identify structural and functional promoter elements upstream of the coding sequence of the ETO gene in order to explore lineage-specific hematopoietic expression and get hints to function. Results A putative proximal ETO promoter was identified within 411 bp upstream of the transcription start site. Strong ETO promoter activity was specifically observed upon transfection of a promoter reporter construct into erythroid/megakaryocytic cells, which have endogeneous ETO gene activity. An evolutionary conserved region of 228 bp revealed potential cis-elements involved in transcription of ETO. Disruption of the evolutionary conserved GATA -636 consensus binding site repressed transactivation and disruption of the ETS1 -705 consensus binding site enhanced activity of the ETO promoter. The promoter was stimulated by overexpression of GATA-1 into erythroid/megakaryocytic cells. Electrophoretic mobility shift assay with erythroid/megakaryocytic cells showed specific binding of GATA-1 to the GATA -636 site. Furthermore, results from chromatin immunoprecipitation showed GATA-1 binding in vivo to the conserved region of the ETO promoter containing the -636 site. The results suggest that the GATA -636 site may have a role in activation of the ETO gene activity in cells with erythroid/megakaryocytic potential. Leukemia associated AML1-ETO strongly suppressed an ETO promoter reporter in erythroid/megakaryocytic cells. Conclusions We demonstrate that the GATA-1 transcription factor binds and

  1. Engineering zinc finger protein transcription factors : The therapeutic relevance of switching endogenous gene expression on or off at command

    NARCIS (Netherlands)

    Gommans, WM; Haisma, HJ; Rots, MG

    2005-01-01

    Modulating gene expression directly at the DNA level represents a novel approach to control cellular processes. In this respect, zinc finger protein DNA-binding domains can be engineered to target virtually any gene. Coupling of a transcription activation or repression domain to these zinc fingers

  2. Hippo Component TAZ Functions as a Co-repressor and Negatively Regulates ΔNp63 Transcription through TEA Domain (TEAD) Transcription Factor*

    Science.gov (United States)

    Valencia-Sama, Ivette; Zhao, Yulei; Lai, Dulcie; Janse van Rensburg, Helena J.; Hao, Yawei; Yang, Xiaolong

    2015-01-01

    Transcriptional co-activator with a PDZ binding domain (TAZ) is a WW domain-containing transcriptional co-activator and a core component of an emerging Hippo signaling pathway that regulates organ size, tumorigenesis, metastasis, and drug resistance. TAZ regulates these biological functions by up-regulating downstream cellular genes through transactivation of transcription factors such as TEAD and TTF1. To understand the molecular mechanisms underlying TAZ-induced tumorigenesis, we have recently performed a gene expression profile analysis by overexpressing TAZ in mammary cells. In addition to the TAZ-up-regulated genes that were confirmed in our previous studies, we identified a large number of cellular genes that were down-regulated by TAZ. In this study, we have confirmed these down-regulated genes (including cytokines, chemokines, and p53 gene family members) as bona fide downstream transcriptional targets of TAZ. By using human breast and lung epithelial cells, we have further characterized ΔNp63, a p53 gene family member, and shown that TAZ suppresses ΔNp63 mRNA, protein expression, and promoter activity through interaction with the transcription factor TEAD. We also show that TEAD can inhibit ΔNp63 promoter activity and that TAZ can directly interact with ΔNp63 promoter-containing TEAD binding sites. Finally, we provide functional evidence that down-regulation of ΔNp63 by TAZ may play a role in regulating cell migration. Altogether, this study provides novel evidence that the Hippo component TAZ can function as a co-repressor and regulate biological functions by negatively regulating downstream cellular genes. PMID:25995450

  3. Hippo Component TAZ Functions as a Co-repressor and Negatively Regulates ΔNp63 Transcription through TEA Domain (TEAD) Transcription Factor.

    Science.gov (United States)

    Valencia-Sama, Ivette; Zhao, Yulei; Lai, Dulcie; Janse van Rensburg, Helena J; Hao, Yawei; Yang, Xiaolong

    2015-07-03

    Transcriptional co-activator with a PDZ binding domain (TAZ) is a WW domain-containing transcriptional co-activator and a core component of an emerging Hippo signaling pathway that regulates organ size, tumorigenesis, metastasis, and drug resistance. TAZ regulates these biological functions by up-regulating downstream cellular genes through transactivation of transcription factors such as TEAD and TTF1. To understand the molecular mechanisms underlying TAZ-induced tumorigenesis, we have recently performed a gene expression profile analysis by overexpressing TAZ in mammary cells. In addition to the TAZ-up-regulated genes that were confirmed in our previous studies, we identified a large number of cellular genes that were down-regulated by TAZ. In this study, we have confirmed these down-regulated genes (including cytokines, chemokines, and p53 gene family members) as bona fide downstream transcriptional targets of TAZ. By using human breast and lung epithelial cells, we have further characterized ΔNp63, a p53 gene family member, and shown that TAZ suppresses ΔNp63 mRNA, protein expression, and promoter activity through interaction with the transcription factor TEAD. We also show that TEAD can inhibit ΔNp63 promoter activity and that TAZ can directly interact with ΔNp63 promoter-containing TEAD binding sites. Finally, we provide functional evidence that down-regulation of ΔNp63 by TAZ may play a role in regulating cell migration. Altogether, this study provides novel evidence that the Hippo component TAZ can function as a co-repressor and regulate biological functions by negatively regulating downstream cellular genes. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  4. Overexpression of the transcriptional repressor complex BCL-6/BCoR leads to nuclear aggregates distinct from classical aggresomes.

    Directory of Open Access Journals (Sweden)

    Elisabeth Buchberger

    Full Text Available Nuclear inclusions of aggregated proteins have primarily been characterized for molecules with aberrant poly-glutamine repeats and for mutated or structurally altered proteins. They were termed "nuclear aggresomes" and misfolding was shown to promote association with molecular chaperones and proteasomes. Here, we report that two components of a transcriptional repressor complex (BCL-6 and BCoR of wildtype amino acid sequence can independently or jointly induce the formation of nuclear aggregates when overexpressed. The observation that the majority of cells rapidly downregulate BCL-6/BCoR levels, supports the notion that expression of these proteins is under tight control. The inclusions occur when BCL-6/BCoR expression exceeds 150-fold of endogenous levels. They preferentially develop in the nucleus by a gradual increase in aggregate size to form large, spheroid structures which are not associated with heat shock proteins or marked by ubiquitin. In contrast, we find the close association of BCL-6/BCoR inclusions with PML bodies and a reduction in aggregation upon the concomitant overexpression of histone deacetylases or heat shock protein 70. In summary, our data offer a perspective on nuclear aggregates distinct from classical "nuclear aggresomes": Large complexes of spheroid structure can evolve in the nucleus without being marked by the cellular machinery for protein refolding and degradation. However, nuclear proteostasis can be restored by balancing the levels of chaperones.

  5. The filamentous growth MAPK Pathway Responds to Glucose Starvation Through the Mig1/2 transcriptional repressors in Saccharomyces cerevisiae.

    Science.gov (United States)

    Karunanithi, Sheelarani; Cullen, Paul J

    2012-11-01

    In the budding yeast S. cerevisiae, nutrient limitation induces a MAPK pathway that regulates filamentous growth and biofilm/mat formation. How nutrient levels feed into the regulation of the filamentous growth pathway is not entirely clear. We characterized a newly identified MAPK regulatory protein of the filamentous growth pathway, Opy2. A two-hybrid screen with the cytosolic domain of Opy2 uncovered new interacting partners including a transcriptional repressor that functions in the AMPK pathway, Mig1, and its close functional homolog, Mig2. Mig1 and Mig2 coregulated the filamentous growth pathway in response to glucose limitation, as did the AMP kinase Snf1. In addition to associating with Opy2, Mig1 and Mig2 interacted with other regulators of the filamentous growth pathway including the cytosolic domain of the signaling mucin Msb2, the MAP kinase kinase Ste7, and the MAP kinase Kss1. As for Opy2, Mig1 overproduction dampened the pheromone response pathway, which implicates Mig1 and Opy2 as potential regulators of pathway specificity. Taken together, our findings provide the first regulatory link in yeast between components of the AMPK pathway and a MAPK pathway that controls cellular differentiation.

  6. Small ubiquitin-like modifier (SUMO) conjugation impedes transcriptional silencing by the polycomb group repressor Sex Comb on Midleg.

    Science.gov (United States)

    Smith, Matthew; Mallin, Daniel R; Simon, Jeffrey A; Courey, Albert J

    2011-04-01

    The Drosophila protein Sex Comb on Midleg (Scm) is a member of the Polycomb group (PcG), a set of transcriptional repressors that maintain silencing of homeotic genes during development. Recent findings have identified PcG proteins both as targets for modification by the small ubiquitin-like modifier (SUMO) protein and as catalytic components of the SUMO conjugation pathway. We have found that the SUMO-conjugating enzyme Ubc9 binds to Scm and that this interaction, which requires the Scm C-terminal sterile α motif (SAM) domain, is crucial for the efficient sumoylation of Scm. Scm is associated with the major Polycomb response element (PRE) of the homeotic gene Ultrabithorax (Ubx), and efficient PRE recruitment requires an intact Scm SAM domain. Global reduction of sumoylation augments binding of Scm to the PRE. This is likely to be a direct effect of Scm sumoylation because mutations in the SUMO acceptor sites in Scm enhance its recruitment to the PRE, whereas translational fusion of SUMO to the Scm N terminus interferes with this recruitment. In the metathorax, Ubx expression promotes haltere formation and suppresses wing development. When SUMO levels are reduced, we observe decreased expression of Ubx and partial haltere-to-wing transformation phenotypes. These observations suggest that SUMO negatively regulates Scm function by impeding its recruitment to the Ubx major PRE.

  7. Small Ubiquitin-like Modifier (SUMO) Conjugation Impedes Transcriptional Silencing by the Polycomb Group Repressor Sex Comb on Midleg*

    Science.gov (United States)

    Smith, Matthew; Mallin, Daniel R.; Simon, Jeffrey A.; Courey, Albert J.

    2011-01-01

    The Drosophila protein Sex Comb on Midleg (Scm) is a member of the Polycomb group (PcG), a set of transcriptional repressors that maintain silencing of homeotic genes during development. Recent findings have identified PcG proteins both as targets for modification by the small ubiquitin-like modifier (SUMO) protein and as catalytic components of the SUMO conjugation pathway. We have found that the SUMO-conjugating enzyme Ubc9 binds to Scm and that this interaction, which requires the Scm C-terminal sterile α motif (SAM) domain, is crucial for the efficient sumoylation of Scm. Scm is associated with the major Polycomb response element (PRE) of the homeotic gene Ultrabithorax (Ubx), and efficient PRE recruitment requires an intact Scm SAM domain. Global reduction of sumoylation augments binding of Scm to the PRE. This is likely to be a direct effect of Scm sumoylation because mutations in the SUMO acceptor sites in Scm enhance its recruitment to the PRE, whereas translational fusion of SUMO to the Scm N terminus interferes with this recruitment. In the metathorax, Ubx expression promotes haltere formation and suppresses wing development. When SUMO levels are reduced, we observe decreased expression of Ubx and partial haltere-to-wing transformation phenotypes. These observations suggest that SUMO negatively regulates Scm function by impeding its recruitment to the Ubx major PRE. PMID:21278366

  8. PA3225 Is a Transcriptional Repressor of Antibiotic Resistance Mechanisms in Pseudomonas aeruginosa

    OpenAIRE

    Hall, Clayton W.; Zhang, Li; Mah, Thien-Fah

    2017-01-01

    ABSTRACT The tssABC1 locus is part of the Hcp secretion island I (HSI-I) type VI secretion system (T6SS) in Pseudomonas aeruginosa. Previous work implicated the tssC1 gene in P. aeruginosa biofilm-specific antibiotic resistance, and tssC1 is preferentially expressed in biofilms compared to planktonic cells. Using a DNA-dependent protein pulldown approach, we discovered that PA3225, an uncharacterized LysR-type transcriptional regulator, specifically bound to the tssABC1 upstream regulatory re...

  9. PA3225 Is a Transcriptional Repressor of Antibiotic Resistance Mechanisms in Pseudomonas aeruginosa.

    Science.gov (United States)

    Hall, Clayton W; Zhang, Li; Mah, Thien-Fah

    2017-08-01

    The tssABC1 locus is part of the Hcp secretion island I (HSI-I) type VI secretion system (T6SS) in Pseudomonas aeruginosa Previous work implicated the tssC1 gene in P. aeruginosa biofilm-specific antibiotic resistance, and tssC1 is preferentially expressed in biofilms compared to planktonic cells. Using a DNA-dependent protein pulldown approach, we discovered that PA3225, an uncharacterized LysR-type transcriptional regulator, specifically bound to the tssABC1 upstream regulatory region. The deletion of PA3225 led to a 2-fold decrease in tssA1 expression levels in planktonic cells compared to the wild type, and tssA1 expression was slightly reduced in ΔPA3225 biofilms compared to wild-type biofilms. Intriguingly, further investigations revealed that the ΔPA3225 mutant was less susceptible to multiple, structurally unrelated antibiotics with various mechanisms of action when grown planktonically. The ΔPA3225 mutant was additionally more resistant to ciprofloxacin when grown in a biofilm. The decreased antibiotic susceptibility of the ΔPA3225 strain was linked to the transcriptional upregulation of the MexAB-OprM efflux pump. By using transcriptome sequencing (RNA-seq), other PA3225-regulated genes were identified, and the products of these genes, such as the putative ABC transporter PA3228, may also contribute to antibiotic resistance. Copyright © 2017 Hall et al.

  10. CYCLING DOF FACTOR 1 represses transcription through the TOPLESS co-repressor to control photoperiodic flowering in Arabidopsis.

    Science.gov (United States)

    Goralogia, Greg S; Liu, Tong-Kun; Zhao, Lin; Panipinto, Paul M; Groover, Evan D; Bains, Yashkarn S; Imaizumi, Takato

    2017-10-01

    CYCLING DOF FACTOR 1 (CDF1) and its homologs play an important role in the floral transition by repressing the expression of floral activator genes such as CONSTANS (CO) and FLOWERING LOCUS T (FT) in Arabidopsis. The day-length-specific removal of CDF1-dependent repression is a critical mechanism in photoperiodic flowering. However, the mechanism by which CDF1 represses CO and FT transcription remained elusive. Here we demonstrate that Arabidopsis CDF proteins contain non-EAR motif-like conserved domains required for interaction with the TOPLESS (TPL) co-repressor protein. This TPL interaction confers a repressive function on CDF1, as mutations of the N-terminal TPL binding domain largely impair the ability of CDF1 protein to repress its targets. TPL proteins are present on specific regions of the CO and FT promoters where CDF1 binds during the morning. In addition, TPL binding increases when CDF1 expression is elevated, suggesting that TPL is recruited to these promoters in a time-dependent fashion by CDFs. Moreover, reduction of TPL activity induced by expressing a dominant negative version of TPL (tpl-1) in phloem companion cells results in early flowering and a decreased sensitivity to photoperiod in a manner similar to a cdf loss-of-function mutant. Our results indicate that the mechanism of CDF1 repression is through the formation of a CDF-TPL transcriptional complex, which reduces the expression levels of CO and FT during the morning for seasonal flowering. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

  11. Chromosomal instability in mouse embryonic fibroblasts null for the transcriptional co-repressor Ski

    Science.gov (United States)

    Marcelain, Katherine; Armisen, Ricardo; Aguirre, Adam; Ueki, Nobuhide; Toro, Jessica; Colmenares, Clemencia; Hayman, Michael J

    2011-01-01

    Ski is a transcriptional regulator that has been considered an oncoprotein, given its ability to induce oncogenic transformation in avian model systems. However, studies in mouse and in some human tumor cells have also indicated a tumor suppressor activity for this protein. We found that Ski−/− mouse embryo fibroblasts exhibit high levels of genome instability, namely aneuploidy, consistent with a tumor suppressor function for Ski. Time-lapse microscopy revealed lagging chromosomes and chromatin/chromosome bridges as the major cause of micronuclei formation and the subsequent aneuploidy. Although these cells arrested in mitosis after treatment with spindle disrupting drugs and exhibited a delayed metaphase/anaphase transition, Spindle Assembly Checkpoint (SAC) was not sufficient to prevent chromosome missegregation, consistent with a weakened SAC. Our in vivo analysis also showed dynamic metaphase plate rearrangements with switches in polarity in cells arrested in metaphase. Importantly, after ectopic expression of Ski the cells that displayed this metaphase arrest died directly during metaphase or after aberrant cell division, relating SAC activation and mitotic cell death. This increased susceptibility to undergo mitosis-associated cell death reduced the number of micronuclei-containing cells. The presented data support a new role for Ski in the mitotic process and in maintenance of genetic stability, providing insights into the mechanism of tumor suppression mediated by this protein. PMID:21412778

  12. Transcriptional activation capacity of the novel PLAG family of zinc finger proteins.

    Science.gov (United States)

    Kas, K; Voz, M L; Hensen, K; Meyen, E; Van de Ven, W J

    1998-09-04

    We have isolated and characterized two novel cDNAs encoding C2H2 zinc finger proteins showing high sequence homology to PLAG1, a protein ectopically activated by promoter swapping or promoter substitution in pleomorphic adenomas with chromosomal abnormalities at chromosome 8q12. PLAG1 and the two new PLAG1 family members (PLAGL1 and PLAGL2) constitute a novel subfamily of zinc finger proteins that recognize DNA and/or RNA. To examine the potential of the three human proteins to modulate transcription, we constructed several PLAG/GAL4 DNA binding domain fusion proteins and measured their ability to activate transcription of a reporter gene construct in different mammalian cell lines and in yeast. Although the carboxyl-terminal part of PLAGL1 shows strong overall transcriptional activity in mesenchymal (COS-1) and epithelial cells (293), both PLAG1 and PLAGL2 transactivate in mesenchymal cells only if depleted from a repressing region. This effect is less profound in epithelial cells. These data suggest that the activation in pleomorphic adenomas of PLAG1 most likely results in uncontrolled activation of downstream target genes.

  13. The switch from fermentation to respiration in Saccharomyces cerevisiae is regulated by the Ert1 transcriptional activator/repressor.

    Science.gov (United States)

    Gasmi, Najla; Jacques, Pierre-Etienne; Klimova, Natalia; Guo, Xiao; Ricciardi, Alessandra; Robert, François; Turcotte, Bernard

    2014-10-01

    In the yeast Saccharomyces cerevisiae, fermentation is the major pathway for energy production, even under aerobic conditions. However, when glucose becomes scarce, ethanol produced during fermentation is used as a carbon source, requiring a shift to respiration. This adaptation results in massive reprogramming of gene expression. Increased expression of genes for gluconeogenesis and the glyoxylate cycle is observed upon a shift to ethanol and, conversely, expression of some fermentation genes is reduced. The zinc cluster proteins Cat8, Sip4, and Rds2, as well as Adr1, have been shown to mediate this reprogramming of gene expression. In this study, we have characterized the gene YBR239C encoding a putative zinc cluster protein and it was named ERT1 (ethanol regulated transcription factor 1). ChIP-chip analysis showed that Ert1 binds to a limited number of targets in the presence of glucose. The strongest enrichment was observed at the promoter of PCK1 encoding an important gluconeogenic enzyme. With ethanol as the carbon source, enrichment was observed with many additional genes involved in gluconeogenesis and mitochondrial function. Use of lacZ reporters and quantitative RT-PCR analyses demonstrated that Ert1 regulates expression of its target genes in a manner that is highly redundant with other regulators of gluconeogenesis. Interestingly, in the presence of ethanol, Ert1 is a repressor of PDC1 encoding an important enzyme for fermentation. We also show that Ert1 binds directly to the PCK1 and PDC1 promoters. In summary, Ert1 is a novel factor involved in the regulation of gluconeogenesis as well as a key fermentation gene. Copyright © 2014 by the Genetics Society of America.

  14. The role of the DNA-binding One Zinc Finger (DOF) transcription factor family in plants.

    Science.gov (United States)

    Noguero, Mélanie; Atif, Rana Muhammad; Ochatt, Sergio; Thompson, Richard D

    2013-08-01

    The DOF (DNA-binding One Zinc Finger) family of transcription factors is involved in many fundamental processes in higher plants, including responses to light and phytohormones as well as roles in seed maturation and germination. DOF transcription factor genes are restricted in their distribution to plants, where they are in many copies in both gymnosperms and angiosperms and also present in lower plants such as the moss Physcomitrella patens and in the alga Chlamydomonas reinhardtii which possesses a single DOF gene. DOF transcription factors bind to their promoter targets at the consensus sequence AAAG. This binding depends upon the presence of the highly conserved DOF domain in the protein. Depending on the target gene, DOF factor binding may activate or repress transcription. DOF factors are expressed in most if not all tissues of higher plants, but frequently appear to be functionally redundant. Recent next-generation sequencing data provide a more comprehensive survey of the distribution of DOF sequence classes among plant species and within tissue types, and clues as to the evolution of functions assumed by this transcription factor family. DOFs do not appear to be implicated in the initial differentiation of the plant body plan into organs via the resolution of meristematic zones, in contrast to MADS-box and homeobox transcription factors, which are found in other non-plant eukaryotes, and this may reflect a more recent evolutionary origin. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  15. Transcriptional Repressor NIR Functions in the Ribosome RNA Processing of Both 40S and 60S Subunits

    Science.gov (United States)

    Wang, Yingshuang; Kong, Ruirui; Hu, Lelin; Schuele, Roland; Du, Xiaojuan; Ke, Yang

    2012-01-01

    Background NIR was identified as an inhibitor of histone acetyltransferase and it represses transcriptional activation of p53. NIR is predominantly localized in the nucleolus and known as Noc2p, which is involved in the maturation of the 60S ribosomal subunit. However, how NIR functions in the nucleolus remains undetermined. In the nucleolus, a 47S ribosomal RNA precursor (pre-rRNA) is transcribed and processed to produce 18S, 5.8S and 28S rRNAs. The 18S rRNA is incorporated into the 40S ribosomal subunit, whereas the 28S and 5.8S rRNAs are incorporated into the 60S subunit. U3 small nucleolar RNA (snoRNA) directs 18S rRNA processing and U8 snoRNA mediates processing of 28S and 5.8 S rRNAs. Functional disruption of nucleolus often causes p53 activation to inhibit cell proliferation. Methodology/Principal Findings Western blotting showed that NIR is ubiquitously expressed in different human cell lines. Knock-down of NIR by siRNA led to inhibition of the 18S, 28S and 5.8S rRNAs evaluated by pulse-chase experiment. Pre-rRNA particles (pre-rRNPs) were fractionated from the nucleus by sucrose gradient centrifugation and analysis of the pre-RNPs components showed that NIR existed in the pre-RNPs of both the 60S and 40S subunits and co-fractionated with 32S and 12S pre-rRNAs in the 60S pre-rRNP. Protein-RNA binding experiments demonstrated that NIR is associated with the 32S pre-rRNA and U8 snoRNA. In addition, NIR bound U3 snoRNA. It is a novel finding that depletion of NIR did not affect p53 protein level but de-repressed acetylation of p53 and activated p21. Conclusions We provide the first evidence for a transcriptional repressor to function in the rRNA biogenesis of both the 40S and 60S subunits. Our findings also suggested that a nucleolar protein may alternatively signal to p53 by affecting the p53 modification rather than affecting p53 protein level. PMID:22363708

  16. Bacillus subtilis IolQ (DegA) is a transcriptional repressor of iolX encoding NAD+-dependent scyllo-inositol dehydrogenase.

    Science.gov (United States)

    Kang, Dong-Min; Michon, Christophe; Morinaga, Tetsuro; Tanaka, Kosei; Takenaka, Shinji; Ishikawa, Shu; Yoshida, Ken-Ichi

    2017-07-11

    Bacillus subtilis is able to utilize at least three inositol stereoisomers as carbon sources, myo-, scyllo-, and D-chiro-inositol (MI, SI, and DCI, respectively). NAD + -dependent SI dehydrogenase responsible for SI catabolism is encoded by iolX. Even in the absence of functional iolX, the presence of SI or MI in the growth medium was found to induce the transcription of iolX through an unknown mechanism. Immediately upstream of iolX, there is an operon that encodes two genes, yisR and iolQ (formerly known as degA), each of which could encode a transcriptional regulator. Here we performed an inactivation analysis of yisR and iolQ and found that iolQ encodes a repressor of the iolX transcription. The coding sequence of iolQ was expressed in Escherichia coli and the gene product was purified as a His-tagged fusion protein, which bound to two sites within the iolX promoter region in vitro. IolQ is a transcriptional repressor of iolX. Genetic evidences allowed us to speculate that SI and MI might possibly be the intracellular inducers, however they failed to antagonize DNA binding of IolQ in in vitro experiments.

  17. The Drosophila Zinc Finger Transcription Factor Ouija Board Controls Ecdysteroid Biosynthesis through Specific Regulation of spookier.

    Directory of Open Access Journals (Sweden)

    Tatsuya Komura-Kawa

    2015-12-01

    Full Text Available Steroid hormones are crucial for many biological events in multicellular organisms. In insects, the principal steroid hormones are ecdysteroids, which play essential roles in regulating molting and metamorphosis. During larval and pupal development, ecdysteroids are synthesized in the prothoracic gland (PG from dietary cholesterol via a series of hydroxylation and oxidation steps. The expression of all but one of the known ecdysteroid biosynthetic enzymes is restricted to the PG, but the transcriptional regulatory networks responsible for generating such exquisite tissue-specific regulation is only beginning to be elucidated. Here, we report identification and characterization of the C2H2-type zinc finger transcription factor Ouija board (Ouib necessary for ecdysteroid production in the PG in the fruit fly Drosophila melanogaster. Expression of ouib is predominantly limited to the PG, and genetic null mutants of ouib result in larval developmental arrest that can be rescued by administrating an active ecdysteroid. Interestingly, ouib mutant animals exhibit a strong reduction in the expression of one ecdysteroid biosynthetic enzyme, spookier. Using a cell culture-based luciferase reporter assay, Ouib protein stimulates transcription of spok by binding to a specific ~15 bp response element in the spok PG enhancer element. Most remarkable, the developmental arrest phenotype of ouib mutants is rescued by over-expression of a functionally-equivalent paralog of spookier. These observations imply that the main biological function of Ouib is to specifically regulate spookier transcription during Drosophila development.

  18. SUMOylation of the KRAB zinc-finger transcription factor PARIS/ZNF746 regulates its transcriptional activity

    Energy Technology Data Exchange (ETDEWEB)

    Nishida, Tamotsu, E-mail: nishida@gene.mie-u.ac.jp; Yamada, Yoshiji

    2016-05-13

    Parkin-interacting substrate (PARIS), a member of the family of Krüppel-associated box (KRAB)-containing zinc-finger transcription factors, is a substrate of the ubiquitin E3 ligase parkin. PARIS represses the expression of peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α), although the underlying mechanisms remain largely unknown. In the present study, we demonstrate that PARIS can be SUMOylated, and its SUMOylation plays a role in the repression of PGC-1a promoter activity. Protein inhibitor of activated STAT y (PIASy) was identified as an interacting protein of PARIS and shown to enhance its SUMOylation. PIASy repressed PGC-1a promoter activity, and this effect was attenuated by PARIS in a manner dependent on its SUMOylation status. Co-expression of SUMO-1 with PIASy completely repressed PGC-1a promoter activity independently of PARIS expression. PARIS-mediated PGC-1a promoter repression depended on the activity of histone deacetylases (HDAC), whereas PIASy repressed the PGC-1a promoter in an HDAC-independent manner. Taken together, these results suggest that PARIS and PIASy modulate PGC-1a gene transcription through distinct molecular mechanisms. -- Highlights: •PARIS can be SUMOylated in vivo and in vitro. •SUMOylation of PARIS functions in the repression of PGC-1a promoter activity. •PIASy interacts with PARIS and enhances its SUMOylation. •PIASy influences PARIS-mediated repression of PGC-1a promoter activity.

  19. The tumor suppressor gene hypermethylated in cancer 1 is transcriptionally regulated by E2F1

    DEFF Research Database (Denmark)

    Jenal, Mathias; Trinh, Emmanuelle; Britschgi, Christian

    2009-01-01

    The Hypermethylated in Cancer 1 (HIC1) gene encodes a zinc finger transcriptional repressor that cooperates with p53 to suppress cancer development. We and others recently showed that HIC1 is a transcriptional target of p53. To identify additional transcriptional regulators of HIC1, we screened...

  20. Functional promoter variant in zinc finger protein 202 predicts severe atherosclerosis and ischemic heart disease

    DEFF Research Database (Denmark)

    Frikke-Schmidt, R.; Nordestgaard, Børge; Grande, Peer

    2008-01-01

    Objectives This study was designed to test the hypotheses that single nucleotide polymorphisms ( SNPs), in zinc finger protein 202 ( ZNF202), predict severe atherosclerosis and ischemic heart disease ( IHD). Background ZNF202 is a transcriptional repressor controlling promoter elements in genes...

  1. Mediation of suppression of c-fos transcription in rasT24-transformed rat cells by a cis-acting repressor element.

    Science.gov (United States)

    Osei-Frimpong, J; Sepulveda, J; Rangdaeng, S; Lebovitz, R M

    1994-06-01

    Prolonged expression of activated ras mutants resulted in both neoplastic transformation and suppression of serum-induced c-fos expression in Rat1 fibroblasts. Expression of other serum-inducible genes, including c-jun and beta-actin, was not suppressed in ras-transformed Rat1 cells, indicating that these effects are specific for c-fos and that growth-factor signal transduction pathways remain essentially intact. Run-on transcription studies indicated that c-fos transcription was blocked at the level of initiation in these cells. Transient transfection studies using 360 bp from the wild-type c-fos promoter as well as a series of mutated c-fos promoter fragments linked to the chloramphenicol acetyltransferase gene indicated that repression of c-fos was mediated by approximately 49 bp immediately upstream of the dyad symmetry element (DSE). Deletion of this region, referred to as the upstream repressor region (URR), restored serum inducibility to the c-fos promoter in ras-transformed cells. In contrast, suppression of c-fos transcription was not affected by either deletion of 240 bp between the DSE and the TATA element or by base-substitution mutations that inactive the ternary complex factor and fos-AP-1-like binding sites. In addition, in vitro competition studies indicated that ras-transformed cells express one or more repressor factors that interact with as-yet-unidentified elements within the c-fos promoter (possibly the URR) and block serum induction of c-fos. These findings suggest that prolonged expression of activated ras results in the activation of one or more as-yet-unidentified proteins that suppress transcription of the c-fos gene by interacting with the URR.

  2. Physical and functional sensitivity of zinc finger transcription factors to redox change.

    Science.gov (United States)

    Wu, X; Bishopric, N H; Discher, D J; Murphy, B J; Webster, K A

    1996-01-01

    Redox regulation of DNA-binding proteins through the reversible oxidation of key cysteine sulfhydryl groups has been demonstrated to occur in vitro for a range of transcription factors. The direct redox regulation of DNA binding has not been described in vivo, possibly because most protein thiol groups are strongly buffered against oxidation by the highly reduced intracellular environment mediated by glutathione, thioredoxin, and associated pathways. For this reason, only accessible protein thiol groups with high thiol-disulfide oxidation potentials are likely to be responsive to intracellular redox changes. In this article, we demonstrate that zinc finger DNA-binding proteins, in particular members of the Sp-1 family, appear to contain such redox-sensitive -SH groups. These proteins displayed a higher sensitivity to redox regulation than other redox-responsive factors both in vitro and in vivo. This effect was reflected in the hyperoxidative repression of transcription from promoters with essential Sp-1 binding sites, including the simian virus 40 early region, glycolytic enzyme, and dihydrofolate reductase genes. Promoter analyses implicated the Sp-1 sites in this repression. Non-Sp-1-dependent redox-regulated genes including metallothionein and heme oxygenase were induced by the same hyperoxic stress. The studies demonstrate that cellular redox changes can directly regulate gene expression in vivo by determining the level of occupancy of strategically positioned GC-binding sites. PMID:8622648

  3. Epigenetic regulation of puberty via Zinc finger protein-mediated transcriptional repression.

    Science.gov (United States)

    Lomniczi, Alejandro; Wright, Hollis; Castellano, Juan Manuel; Matagne, Valerie; Toro, Carlos A; Ramaswamy, Suresh; Plant, Tony M; Ojeda, Sergio R

    2015-12-16

    In primates, puberty is unleashed by increased GnRH release from the hypothalamus following an interval of juvenile quiescence. GWAS implicates Zinc finger (ZNF) genes in timing human puberty. Here we show that hypothalamic expression of several ZNFs decreased in agonadal male monkeys in association with the pubertal reactivation of gonadotropin secretion. Expression of two of these ZNFs, GATAD1 and ZNF573, also decreases in peripubertal female monkeys. However, only GATAD1 abundance increases when gonadotropin secretion is suppressed during late infancy. Targeted delivery of GATAD1 or ZNF573 to the rat hypothalamus delays puberty by impairing the transition of a transcriptional network from an immature repressive epigenetic configuration to one of activation. GATAD1 represses transcription of two key puberty-related genes, KISS1 and TAC3, directly, and reduces the activating histone mark H3K4me2 at each promoter via recruitment of histone demethylase KDM1A. We conclude that GATAD1 epitomizes a subset of ZNFs involved in epigenetic repression of primate puberty.

  4. D-Serine/N-methyl-D-aspartate receptor signaling decreases DNA-binding activity of the transcriptional repressor DREAM in Müller glia from the retina.

    Science.gov (United States)

    Chavira-Suárez, Erika; Ramírez, Mónica; Lamas, Mónica

    2008-02-20

    In the adult retina, N-methyl-D-aspartate (NMDA) neurotoxicity induces Müller cell reactive gliosis which is characterized by changes in gene expression that lead to proliferation and affect retinal physiology. The amino acid D-serine is synthesized in Müller cells and modulates these processes acting as a coagonist of NMDA receptors. We have found that the transcription factor DREAM (downstream regulatory element antagonist modulator), which acts as a transcriptional repressor by binding as a tetramer to regulatory elements located in the promoter region of target genes, is expressed in these cells and that its DNA-binding activity is modulated by NMDA receptor activation. Consistently, immunocytochemical analysis demonstrates that NMDA receptor activation induces changes in the nuclear localization of this transcription factor. DREAM is a pleiotropic transcription factor capable to repress and activate genes involved in several physiological events in different tissues. These results link, for the first time, this transcription factor with NMDA-receptor activation. Given the relevance of glutamatergic transmission in the retina and the remarkable functional plasticity of Müller cells, these findings support the notion that the NMDA receptor-dependent modulation of DREAM activity could play a role in relevant physiological processes ranging from retinal response to injury to differentiation capacity of retinal progenitor cells.

  5. Post-transcriptional regulation of the trypanosome heat shock response by a zinc finger protein.

    Directory of Open Access Journals (Sweden)

    Dorothea Droll

    Full Text Available In most organisms, the heat-shock response involves increased heat-shock gene transcription. In Kinetoplastid protists, however, virtually all control of gene expression is post-transcriptional. Correspondingly, Trypanosoma brucei heat-shock protein 70 (HSP70 synthesis after heat shock depends on regulation of HSP70 mRNA turnover. We here show that the T. brucei CCCH zinc finger protein ZC3H11 is a post-transcriptional regulator of trypanosome chaperone mRNAs. ZC3H11 is essential in bloodstream-form trypanosomes and for recovery of insect-form trypanosomes from heat shock. ZC3H11 binds to mRNAs encoding heat-shock protein homologues, with clear specificity for the subset of trypanosome chaperones that is required for protein refolding. In procyclic forms, ZC3H11 was required for stabilisation of target chaperone-encoding mRNAs after heat shock, and the HSP70 mRNA was also decreased upon ZC3H11 depletion in bloodstream forms. Many mRNAs bound to ZC3H11 have a consensus AUU repeat motif in the 3'-untranslated region. ZC3H11 bound preferentially to AUU repeats in vitro, and ZC3H11 regulation of HSP70 mRNA in bloodstream forms depended on its AUU repeat region. Tethering of ZC3H11 to a reporter mRNA increased reporter expression, showing that it is capable of actively stabilizing an mRNA. These results show that expression of trypanosome heat-shock genes is controlled by a specific RNA-protein interaction. They also show that heat-shock-induced chaperone expression in procyclic trypanosome enhances parasite survival at elevated temperatures.

  6. FACT, the Bur kinase pathway, and the histone co-repressor HirC have overlapping nucleosome-related roles in yeast transcription elongation.

    Directory of Open Access Journals (Sweden)

    Jennifer R Stevens

    Full Text Available Gene transcription is constrained by the nucleosomal nature of chromosomal DNA. This nucleosomal barrier is modulated by FACT, a conserved histone-binding heterodimer. FACT mediates transcription-linked nucleosome disassembly and also nucleosome reassembly in the wake of the RNA polymerase II transcription complex, and in this way maintains the repression of 'cryptic' promoters found within some genes. Here we focus on a novel mutant version of the yeast FACT subunit Spt16 that supplies essential Spt16 activities but impairs transcription-linked nucleosome reassembly in dominant fashion. This Spt16 mutant protein also has genetic effects that are recessive, which we used to show that certain Spt16 activities collaborate with histone acetylation and the activities of a Bur-kinase/Spt4-Spt5/Paf1C pathway that facilitate transcription elongation. These collaborating activities were opposed by the actions of Rpd3S, a histone deacetylase that restores a repressive chromatin environment in a transcription-linked manner. Spt16 activity paralleling that of HirC, a co-repressor of histone gene expression, was also found to be opposed by Rpd3S. Our findings suggest that Spt16, the Bur/Spt4-Spt5/Paf1C pathway, and normal histone abundance and/or stoichiometry, in mutually cooperative fashion, facilitate nucleosome disassembly during transcription elongation. The recessive nature of these effects of the mutant Spt16 protein on transcription-linked nucleosome disassembly, contrasted to its dominant negative effect on transcription-linked nucleosome reassembly, indicate that mutant FACT harbouring the mutant Spt16 protein competes poorly with normal FACT at the stage of transcription-linked nucleosome disassembly, but effectively with normal FACT for transcription-linked nucleosome reassembly. This functional difference is consistent with the idea that FACT association with the transcription elongation complex depends on nucleosome disassembly, and that the

  7. Zinc finger transcription factors displaced SREBP proteins as the major Sterol regulators during Saccharomycotina evolution.

    Directory of Open Access Journals (Sweden)

    Sarah L Maguire

    2014-01-01

    Full Text Available In most eukaryotes, including the majority of fungi, expression of sterol biosynthesis genes is regulated by Sterol-Regulatory Element Binding Proteins (SREBPs, which are basic helix-loop-helix transcription activators. However, in yeasts such as Saccharomyces cerevisiae and Candida albicans sterol synthesis is instead regulated by Upc2, an unrelated transcription factor with a Gal4-type zinc finger. The SREBPs in S. cerevisiae (Hms1 and C. albicans (Cph2 have lost a domain, are not major regulators of sterol synthesis, and instead regulate filamentous growth. We report here that rewiring of the sterol regulon, with Upc2 taking over from SREBP, likely occurred in the common ancestor of all Saccharomycotina. Yarrowia lipolytica, a deep-branching species, is the only genome known to contain intact and full-length orthologs of both SREBP (Sre1 and Upc2. Deleting YlUPC2, but not YlSRE1, confers susceptibility to azole drugs. Sterol levels are significantly reduced in the YlUPC2 deletion. RNA-seq analysis shows that hypoxic regulation of sterol synthesis genes in Y. lipolytica is predominantly mediated by Upc2. However, YlSre1 still retains a role in hypoxic regulation; growth of Y. lipolytica in hypoxic conditions is reduced in a Ylupc2 deletion and is abolished in a Ylsre1/Ylupc2 double deletion, and YlSre1 regulates sterol gene expression during hypoxia adaptation. We show that YlSRE1, and to a lesser extent YlUPC2, are required for switching from yeast to filamentous growth in hypoxia. Sre1 appears to have an ancestral role in the regulation of filamentation, which became decoupled from its role in sterol gene regulation by the arrival of Upc2 in the Saccharomycotina.

  8. Crystallization and preliminary X-ray analysis of BigR, a transcription repressor from Xylella fastidiosa involved in biofilm formation

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa, Rosicler Lázaro; Rinaldi, Fábio Cupri; Guimarães, Beatriz Gomes, E-mail: beatriz@lnls.br; Benedetti, Celso Eduardo, E-mail: beatriz@lnls.br [Center for Molecular and Structural Biology, Brazilian Synchrotron Light Laboratory, Campinas, SP, CP 6192, CEP 13083-970 (Brazil)

    2007-07-01

    In order to gain new insights into the protein structure and its possible interaction with a metal ion or effector ligand, BigR from X. fastidiosa was crystallized in native and selenomethionine (SeMet) labelled forms using the hanging-drop vapour-diffusion method. BigR (biofilm growth-associated repressor) is a novel repressor protein that regulates the transcription of an operon implicated in biofilm growth in both Xylella fastidiosa and Agrobacterium tumefaciens. This protein binds to a palindromic TA-rich element located in the promoter of the BigR operon and strongly represses transcription of the operon. BigR contains a helix–turn–helix (HTH) domain that is found in some members of the ArsR/SmtB family of metal sensors, which control metal resistance in bacteria. Although functional studies have suggested that BigR does not act as a metal sensor, the presence of two cysteines and a methionine in its primary structure raised the possibility of BigR being a metal-ligand protein. In order to gain new insights into the protein structure and its possible interaction with a metal ion or effector ligand, BigR from X. fastidiosa was crystallized in native and selenomethionine (SeMet) labelled forms using the hanging-drop vapour-diffusion method. X-ray diffraction data were collected from native and SeMet crystals to resolutions of 1.95 and 2.2 Å, respectively. Both crystals belong to space group P321 and contain one molecule per asymmetric unit.

  9. Crystallization and preliminary X-ray analysis of BigR, a transcription repressor from Xylella fastidiosa involved in biofilm formation

    International Nuclear Information System (INIS)

    Barbosa, Rosicler Lázaro; Rinaldi, Fábio Cupri; Guimarães, Beatriz Gomes; Benedetti, Celso Eduardo

    2007-01-01

    In order to gain new insights into the protein structure and its possible interaction with a metal ion or effector ligand, BigR from X. fastidiosa was crystallized in native and selenomethionine (SeMet) labelled forms using the hanging-drop vapour-diffusion method. BigR (biofilm growth-associated repressor) is a novel repressor protein that regulates the transcription of an operon implicated in biofilm growth in both Xylella fastidiosa and Agrobacterium tumefaciens. This protein binds to a palindromic TA-rich element located in the promoter of the BigR operon and strongly represses transcription of the operon. BigR contains a helix–turn–helix (HTH) domain that is found in some members of the ArsR/SmtB family of metal sensors, which control metal resistance in bacteria. Although functional studies have suggested that BigR does not act as a metal sensor, the presence of two cysteines and a methionine in its primary structure raised the possibility of BigR being a metal-ligand protein. In order to gain new insights into the protein structure and its possible interaction with a metal ion or effector ligand, BigR from X. fastidiosa was crystallized in native and selenomethionine (SeMet) labelled forms using the hanging-drop vapour-diffusion method. X-ray diffraction data were collected from native and SeMet crystals to resolutions of 1.95 and 2.2 Å, respectively. Both crystals belong to space group P321 and contain one molecule per asymmetric unit

  10. Disruption of a Transcriptional Repressor by an Insertion Sequence Element Integration Leads to Activation of a Novel Silent Cellobiose Transporter in Lactococcus lactis MG1363.

    Science.gov (United States)

    Solopova, Ana; Kok, Jan; Kuipers, Oscar P

    2017-12-01

    Lactococcus lactis subsp. cremoris strains typically carry many dairy niche-specific adaptations. During adaptation to the milk environment these former plant strains have acquired various pseudogenes and insertion sequence elements indicative of ongoing genome decay and frequent transposition events in their genomes. Here we describe the reactivation of a silenced plant sugar utilization cluster in an L. lactis MG1363 derivative lacking the two main cellobiose transporters, PtcBA-CelB and PtcBAC, upon applying selection pressure to utilize cellobiose. A disruption of the transcriptional repressor gene llmg_1239 by an insertion sequence (IS) element allows expression of the otherwise silent novel cellobiose transporter Llmg_1244 and leads to growth of mutant strains on cellobiose. Llmg_1239 was labeled CclR, for c ellobiose cl uster r epressor. IMPORTANCE Insertion sequences (ISs) play an important role in the evolution of lactococci and other bacteria. They facilitate DNA rearrangements and are responsible for creation of new genetic variants with selective advantages under certain environmental conditions. L. lactis MG1363 possesses 71 copies in a total of 11 different types of IS elements. This study describes yet another example of an IS-mediated adaptive evolution. An integration of IS 981 or IS 905 into a gene coding for a transcriptional repressor led to activation of the repressed gene cluster coding for a plant sugar utilization pathway. The expression of the gene cluster allowed assembly of a novel cellobiose-specific transporter and led to cell growth on cellobiose. Copyright © 2017 American Society for Microbiology.

  11. Specific reactivation of latent HIV-1 with designer zinc-finger transcription factors targeting the HIV-1 5'-LTR promoter.

    Science.gov (United States)

    Wang, P; Qu, X; Wang, X; Zhu, X; Zeng, H; Chen, H; Zhu, H

    2014-05-01

    HIV-1 latency remains the primary obstacle to the eradication of this virus. The current latency-reversing agents cannot effectively and specifically eliminate latent HIV-1 reservoirs. Therefore, better approaches are urgently needed. In this study, we describe a novel strategy to reactivate latent HIV-1 using zinc-finger transcription factors composed of designer zinc-finger proteins and the transcriptional activation domain VP64. For the first time, we demonstrate that ZF-VP64 with HIV-1 long terminal repeat (LTR) promoter-specific affinity could significantly reactivate HIV-1 expression from latently infected cells without altering cell proliferation or cell cycle progression. We also provide evidence that the reactivation of HIV-1 by ZF-VP64 occurs through specific binding to the 5'-LTR promoter. Our results demonstrate the potential of this novel approach for anti-HIV-1 latency therapy.

  12. A transcription unit at the ken and barbie gene locus encodes a novel Drosophila zinc finger protein.

    Science.gov (United States)

    Kühnlein, R P; Chen, C K; Schuh, R

    1998-12-01

    We describe a novel Drosophila transcription unit, located in chromosome region 60A. It encodes a zinc finger protein that is expressed in distinct spatial and temporal patterns during embryogenesis. Its initial expression occurs in a stripe at the anterior and the posterior trunk boundary, respectively. The two stripes are activated and spatially controlled by gap-gene activities. The P-element of the enhancer trap line l(2)02970 is inserted in the 5'-region of the transcript and causes a ken and barbie (ken) phenotype, associated with malformation of male genital structures.

  13. SarA is a repressor of hla (alpha-hemolysin) transcription in Staphylococcus aureus: its apparent role as an activator of hla in the prototype strain NCTC 8325 depends on reduced expression of sarS.

    Science.gov (United States)

    Oscarsson, Jan; Kanth, Anna; Tegmark-Wisell, Karin; Arvidson, Staffan

    2006-12-01

    In most Staphylococcus aureus strains, inactivation of sarA increases hla transcription, indicating that sarA is a repressor. However, in S. aureus NCTC 8325 and its derivatives, used for most studies of hla regulation, inactivation of sarA resulted in decreased hla transcription. The disparate phenotype of strain NCTC 8325 seems to be associated with its rsbU mutation, which leads to sigma(B) deficiency. This has now been verified by the demonstration that sarA repressed hla transcription in an rsbU+ derivative of strain 8325-4 (SH1000). That sarA could act as a repressor of hla in an 8325-4 background was confirmed by the observation that inactivation of sarA in an agr sarS rot triple mutant dramatically increased hla transcription to wild-type levels. However, the apparent role of sarA as an activator of hla in 8325-4 was not a result of the rsbU mutation alone, as inactivation of sarA in another rsbU mutant, strain V8, led to increased hla transcription. Northern blot analysis revealed much higher levels of sarS mRNA in strain V8 than in 8325-4, which was likely due to the mutation in the sarS activator, tcaR, in 8325-4, which was not found in strain V8. On the other hand, the relative increase in sarS transcription upon the inactivation of sarA was 15-fold higher in 8325-4 than in strain V8. Because of this, inactivation of sarA in 8325-4 means a net increase in repressor activity, whereas in strain V8, inactivation of sarA means a net decrease in repressor activity and, therefore, enhanced hla transcription.

  14. Lymphoid Progenitor Cells from Childhood Acute Lymphoblastic Leukemia Are Functionally Deficient and Express High Levels of the Transcriptional Repressor Gfi-1

    Directory of Open Access Journals (Sweden)

    Jessica Purizaca

    2013-01-01

    Full Text Available Acute lymphoblastic leukemia (ALL is the most frequent malignancy of childhood. Substantial progress on understanding the cell hierarchy within ALL bone marrow (BM has been recorded in the last few years, suggesting that both primitive cell fractions and committed lymphoid blasts with immature stem cell-like properties contain leukemia-initiating cells. Nevertheless, the biology of the early progenitors that initiate the lymphoid program remains elusive. The aim of the present study was to investigate the ability of lymphoid progenitors from B-cell precursor ALL BM to proliferate and undergo multilineage differentiation. By phenotype analyses, in vitro proliferation assays, and controlled culture systems, the lymphoid differentiation potentials were evaluated in BM primitive populations from B-cell precursor ALL pediatric patients. When compared to their normal counterparts, functional stem and progenitor cell contents were substantially reduced in ALL BM. Moreover, neither B nor NK or dendritic lymphoid-cell populations developed recurrently from highly purified ALL-lymphoid progenitors, and their proliferation and cell cycle status revealed limited proliferative capacity. Interestingly, a number of quiescence-associated transcription factors were elevated, including the transcriptional repressor Gfi-1, which was highly expressed in primitive CD34+ cells. Together, our findings reveal major functional defects in the primitive hematopoietic component of ALL BM. A possible contribution of high levels of Gfi-1 expression in the regulation of the stem/progenitor cell biology is suggested.

  15. The Transcriptional Repressor MYB2 Regulates Both Spatial and Temporal Patterns of Proanthocyandin and Anthocyanin Pigmentation in Medicago truncatula[OPEN

    Science.gov (United States)

    2015-01-01

    Accumulation of anthocyanins and proanthocyanidins (PAs) is limited to specific cell types and developmental stages, but little is known about how antagonistically acting transcriptional regulators work together to determine temporal and spatial patterning of pigmentation at the cellular level, especially for PAs. Here, we characterize MYB2, a transcriptional repressor regulating both anthocyanin and PA biosynthesis in the model legume Medicago truncatula. MYB2 was strongly upregulated by MYB5, a major regulator of PA biosynthesis in M. truncatula and a component of MYB-basic helix loop helix-WD40 (MBW) activator complexes. Overexpression of MYB2 abolished anthocyanin and PA accumulation in M. truncatula hairy roots and Arabidopsis thaliana seeds, respectively. Anthocyanin deposition was expanded in myb2 mutant seedlings and flowers accompanied by increased anthocyanin content. PA mainly accumulated in the epidermal layer derived from the outer integument in the M. truncatula seed coat, starting from the hilum area. The area of PA accumulation and ANTHOCYANIDIN REDUCTASE expression was expanded into the seed body at the early stage of seed development in the myb2 mutant. Genetic, biochemical, and cell biological evidence suggests that MYB2 functions as part of a multidimensional regulatory network to define the temporal and spatial pattern of anthocyanin and PA accumulation linked to developmental processes. PMID:26410301

  16. Ret Finger Protein: An E3 Ubiquitin Ligase Juxtaposed to the XY Body in Meiosis

    Directory of Open Access Journals (Sweden)

    Isabelle Gillot

    2009-01-01

    Full Text Available During prophase I of male meiosis, the sex chromosomes form a compact structure called XY body that associates with the nuclear membrane of pachytene spermatocytes. Ret Finger Protein is a transcriptional repressor, able to interact with both nuclear matrix-associated proteins and double-stranded DNA. We report the precise and unique localization of Ret Finger Protein in pachytene spermatocytes, in which Ret Finger Protein takes place of lamin B1, between the XY body and the inner nuclear membrane. This localization of Ret Finger Protein does not seem to be associated with O-glycosylation or sumoylation. In addition, we demonstrate that Ret Finger Protein contains an E3 ubiquitin ligase activity. These observations lead to an attractive hypothesis in which Ret Finger Protein would be involved in the positioning and the attachment of XY body to the nuclear lamina of pachytene spermatocytes.

  17. Defects in the NC2 repressor affect both canonical and non-coding RNA polymerase II transcription initiation in yeast.

    Science.gov (United States)

    Gómez-Navarro, Natalia; Jordán-Pla, Antonio; Estruch, Francisco; E Pérez-Ortín, José

    2016-03-03

    The formation of the pre-initiation complex in eukaryotic genes is a key step in transcription initiation. The TATA-binding protein (TBP) is a universal component of all pre-initiation complexes for all kinds of RNA polymerase II (RNA pol II) genes, including those with a TATA or a TATA-like element, both those that encode proteins and those that transcribe non-coding RNAs. Mot1 and the negative cofactor 2 (NC2) complex are regulators of TBP, and it has been shown that depletion of these factors in yeast leads to defects in the control of transcription initiation that alter cryptic transcription levels in selected yeast loci. In order to cast light on the molecular functions of NC2, we performed genome-wide studies in conditional mutants in yeast NC2 essential subunits Ydr1 and Bur6. Our analyses show a generally increased level of cryptic transcription in all kinds of genes upon depletion of NC2 subunits, and that each kind of gene (canonical or ncRNAs, TATA or TATA-like) shows some differences in the cryptic transcription pattern for each NC2 mutant. We conclude that NC2 plays a general role in transcription initiation in RNA polymerase II genes that is related with its known TBP interchange function from free to promoter bound states. Therefore, loss of the NC2 function provokes increases in cryptic transcription throughout the yeast genome. Our results also suggest functional differences between NC2 subunits Ydr1 and Bur6.

  18. The Bacterial Effector HopX1 Targets JAZ Transcriptional Repressors to Activate Jasmonate Signaling and Promote Infection in Arabidopsis

    Science.gov (United States)

    Gimenez-Ibanez, Selena; Boter, Marta; Fernández-Barbero, Gemma; Chini, Andrea; Rathjen, John P.; Solano, Roberto

    2014-01-01

    Pathogenicity of Pseudomonas syringae is dependent on a type III secretion system, which secretes a suite of virulence effector proteins into the host cytoplasm, and the production of a number of toxins such as coronatine (COR), which is a mimic of the plant hormone jasmonate-isoleuce (JA-Ile). Inside the plant cell, effectors target host molecules to subvert the host cell physiology and disrupt defenses. However, despite the fact that elucidating effector action is essential to understanding bacterial pathogenesis, the molecular function and host targets of the vast majority of effectors remain largely unknown. Here, we found that effector HopX1 from Pseudomonas syringae pv. tabaci (Pta) 11528, a strain that does not produce COR, interacts with and promotes the degradation of JAZ proteins, a key family of JA-repressors. We show that hopX1 encodes a cysteine protease, activity that is required for degradation of JAZs by HopX1. HopX1 associates with JAZ proteins through its central ZIM domain and degradation occurs in a COI1-independent manner. Moreover, ectopic expression of HopX1 in Arabidopsis induces the expression of JA-dependent genes, represses salicylic acid (SA)-induced markers, and complements the growth of a COR-deficient P. syringae pv. tomato (Pto) DC3000 strain during natural bacterial infections. Furthermore, HopX1 promoted susceptibility when delivered by the natural type III secretion system, to a similar extent as the addition of COR, and this effect was dependent on its catalytic activity. Altogether, our results indicate that JAZ proteins are direct targets of bacterial effectors to promote activation of JA-induced defenses and susceptibility in Arabidopsis. HopX1 illustrates a paradigm of an alternative evolutionary solution to COR with similar physiological outcome. PMID:24558350

  19. E2F-6, a member of the E2F family that can behave as a transcriptional repressor.

    Science.gov (United States)

    Trimarchi, J M; Fairchild, B; Verona, R; Moberg, K; Andon, N; Lees, J A

    1998-03-17

    The E2F family of proteins is required to establish the correct cell-cycle-dependent transcription of genes that direct the process of cell division. All previously identified E2F proteins can act in a similar manner; depending on whether or not they are associated with the cell cycle inhibitors the retinoblastoma protein (pRB), p107, or p130, they can either repress or activate the transcription of E2F-responsive genes. We now report the cloning and characterization of another E2F family member, E2F-6, whose structure is reminiscent of the dominant inhibitors of other transcription factor families. The dimerization and DNA binding properties of E2F-6 are similar to those of the other E2F family members. However, it is not regulated by pRB, p107, or p130, and it is unable to activate transcription. Instead, it can act to repress the transcription of E2F responsive genes by countering the activity of the other E2F complexes via a pRB-, p107-, or p130-independent mechanism.

  20. Wnt-mediated down-regulation of Sp1 target genes by a transcriptional repressor Sp5

    Czech Academy of Sciences Publication Activity Database

    Fujimura, Naoko; Vacík, Tomáš; Machoň, Ondřej; Vlček, Čestmír; Scalabrin, S.; Speth, M.; Diep, D.; Krauss, S.; Kozmik, Zbyněk

    2007-01-01

    Roč. 282, č. 2 (2007), s. 1225-1237 ISSN 0021-9258 Institutional research plan: CEZ:AV0Z50520514 Keywords : Wnt -mediated signaling * Sp5 transcription factor * Sp1 target genes Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.581, year: 2007

  1. Zinc fingers 1, 2, 5 and 6 of transcriptional regulator, PRDM4, are required for its nuclear localisation

    International Nuclear Information System (INIS)

    Tunbak, Hale; Georgiou, Christiana; Guan, Cui; Richardson, William David; Chittka, Alexandra

    2016-01-01

    PRDM4 is a member of the PRDM family of transcriptional regulators which control various aspects of cellular differentiation and proliferation. PRDM proteins exert their biological functions both in the cytosol and the nucleus of cells. All PRDM proteins are characterised by the presence of two distinct structural motifs, the PR/SET domain and the zinc finger (ZF) motifs. We previously observed that deletion of all six zinc fingers found in PRDM4 leads to its accumulation in the cytosol, whereas overexpressed full length PRDM4 is found predominantly in the nucleus. Here, we investigated the requirements for single zinc fingers in the nuclear localisation of PRDM4. We demonstrate that ZF's 1, 2, 5 and 6 contribute to the accumulation of PRDM4 in the nucleus. Their effect is additive as deleting either ZF1-2 or ZF 5–6 redistributes PRDM4 protein from being almost exclusively nuclear to cytosolic and nuclear. We investigated the potential mechanism of nuclear shuttling of PRDM4 via the importin α/β-mediated pathway and find that PRDM4 nuclear targeting is independent of α/β-mediated nuclear import. -- Highlights: •Zinc fingers 1, 2, 5, and 6 are necessary for efficient nuclear localisation of PRDM4. •Zinc fingers 3 and 4 are dispensable for nuclear localisation of PRDM4. •Zinc knuckle is dispensable for nuclear localisation of PRDM4. •PRDM4 nuclear transport is independent of importin α/β-mediated pathway of nuclear import.

  2. Zinc fingers 1, 2, 5 and 6 of transcriptional regulator, PRDM4, are required for its nuclear localisation

    Energy Technology Data Exchange (ETDEWEB)

    Tunbak, Hale, E-mail: h.tunbak@ucl.ac.uk [The Wolfson Institute for Biomedical Research, University College London, Gower Street, London WC1E 6BT (United Kingdom); Georgiou, Christiana, E-mail: christiana.georgiou.10@ucl.ac.uk [The Wolfson Institute for Biomedical Research, University College London, Gower Street, London WC1E 6BT (United Kingdom); Guan, Cui, E-mail: c.guan@qmul.ac.uk [School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom); Richardson, William David, E-mail: w.richardson@ucl.ac.uk [The Wolfson Institute for Biomedical Research, University College London, Gower Street, London WC1E 6BT (United Kingdom); Chittka, Alexandra, E-mail: a.chittka@ucl.ac.uk [The Wolfson Institute for Biomedical Research, University College London, Gower Street, London WC1E 6BT (United Kingdom)

    2016-05-27

    PRDM4 is a member of the PRDM family of transcriptional regulators which control various aspects of cellular differentiation and proliferation. PRDM proteins exert their biological functions both in the cytosol and the nucleus of cells. All PRDM proteins are characterised by the presence of two distinct structural motifs, the PR/SET domain and the zinc finger (ZF) motifs. We previously observed that deletion of all six zinc fingers found in PRDM4 leads to its accumulation in the cytosol, whereas overexpressed full length PRDM4 is found predominantly in the nucleus. Here, we investigated the requirements for single zinc fingers in the nuclear localisation of PRDM4. We demonstrate that ZF's 1, 2, 5 and 6 contribute to the accumulation of PRDM4 in the nucleus. Their effect is additive as deleting either ZF1-2 or ZF 5–6 redistributes PRDM4 protein from being almost exclusively nuclear to cytosolic and nuclear. We investigated the potential mechanism of nuclear shuttling of PRDM4 via the importin α/β-mediated pathway and find that PRDM4 nuclear targeting is independent of α/β-mediated nuclear import. -- Highlights: •Zinc fingers 1, 2, 5, and 6 are necessary for efficient nuclear localisation of PRDM4. •Zinc fingers 3 and 4 are dispensable for nuclear localisation of PRDM4. •Zinc knuckle is dispensable for nuclear localisation of PRDM4. •PRDM4 nuclear transport is independent of importin α/β-mediated pathway of nuclear import.

  3. Engineered zinc-finger transcription factors inhibit the replication and transcription of HBV in vitro and in vivo.

    Science.gov (United States)

    Luo, Wei; Wang, Junxia; Xu, Dengfeng; Bai, Huili; Zhang, Yangli; Zhang, Yuhong; Li, Xiaosong

    2018-04-01

    In the present study, an artificial zinc-finger transcription factor eukaryotic expression vector specifically recognizing and binding to the hepatitis B virus (HBV) enhancer (Enh) was constructed, which inhibited the replication and expression of HBV DNA. The HBV EnhI‑specific pcDNA3.1‑artificial transcription factor (ATF) vector was successfully constructed, and then transformed or injected into HepG2.2.15 cells and HBV transgenic mice, respectively. The results demonstrated that the HBV EnhI (1,070‑1,234 bp)‑specific ATF significantly inhibited the replication and transcription of HBV DNA in vivo and in vitro. The HBV EnhI‑specific ATF may be a meritorious component of progressive combination therapies for eliminating HBV DNA in infected patients. A radical cure for chronic HBV infection may become feasible by using this bioengineering technology.

  4. Regulation of MntH by a dual Mn(II- and Fe(II-dependent transcriptional repressor (DR2539 in Deinococcus radiodurans.

    Directory of Open Access Journals (Sweden)

    Hongxing Sun

    Full Text Available The high intracellular Mn/Fe ratio observed within the bacteria Deinococcus radiodurans may contribute to its remarkable resistance to environmental stresses. We isolated DR2539, a novel regulator of intracellular Mn/Fe homeostasis in D. radiodurans. Electrophoretic gel mobility shift assays (EMSAs revealed that DR2539 binds specifically to the promoter of the manganese acquisition transporter (MntH gene, and that DR0865, the only Fur homologue in D. radiodurans, cannot bind to the promoter of mntH, but it can bind to the promoter of another manganese acquisition transporter, MntABC. β-galactosidase expression analysis indicated that DR2539 acts as a manganese- and iron-dependent transcriptional repressor. Further sequence alignment analysis revealed that DR2539 has evolved some special characteristics. Site-directed mutagenesis suggested that His98 plays an important role in the activities of DR2539, and further protein-DNA binding activity assays showed that the activity of H98Y mutants decreased dramatically relative to wild type DR2539. Our study suggests that D. radiodurans has evolved a very efficient manganese regulation mechanism that involves its high intracellular Mn/Fe ratio and permits resistance to extreme conditions.

  5. Zinc finger artificial transcription factor-based nearest inactive analogue/nearest active analogue strategy used for the identification of plant genes controlling homologous recombination

    NARCIS (Netherlands)

    Jia, Qi; van Verk, Marcel C.; Pinas, Johan E.; Lindhout, Beatrice I.; Hooykaas, Paul J.J.; Van der Zaal, Bert J.

    2013-01-01

    In previous work, we selected a particular transcription factor, designated VP16-HRU, from a pool of zinc finger artificial transcription factors (ZF-ATFs) used for genome interrogation. When expressed in Arabidopsis thaliana under control of the ribosomal protein S5A promoter, the RPS5A::VP16-HRU

  6. Arabidopsis R2R3-MYB transcription factor AtMYB60 functions as a transcriptional repressor of anthocyanin biosynthesis in lettuce (Lactuca sativa).

    Science.gov (United States)

    Park, Jong-Sug; Kim, Jung-Bong; Cho, Kang-Jin; Cheon, Choong-Ill; Sung, Mi-Kyung; Choung, Myoung-Gun; Roh, Kyung-Hee

    2008-06-01

    The MYB transcription factors play important roles in the regulation of many secondary metabolites at the transcriptional level. We evaluated the possible roles of the Arabidopsis R2R3-MYB transcription factors in flavonoid biosynthesis because they are induced by UV-B irradiation but their associated phenotypes are largely unexplored. We isolated their genes by RACE-PCR, and performed transgenic approach and metabolite analyses in lettuce (Lactuca sativa). We found that one member of this protein family, AtMYB60, inhibits anthocyanin biosynthesis in the lettuce plant. Wild-type lettuce normally accumulates anthocyanin, predominantly cyanidin and traces of delphinidin, and develops a red pigmentation. However, the production and accumulation of anthocyanin pigments in AtMYB60-overexpressing lettuce was inhibited. Using RT-PCR analysis, we also identified the complete absence or reduction of dihydroflavonol 4-reductase (DFR) transcripts in AtMYB60- overexpressing lettuce (AtMYB60-117 and AtMYB60-112 lines). The correlation between the overexpression of AtMYB60 and the inhibition of anthocyanin accumulation suggests that the transcription factorAtMYB60 controls anthocyanin biosynthesis in the lettuce leaf. Clarification of the roles of the AtMYB60 transcription factor will facilitate further studies and provide genetic tools to better understand the regulation in plants of the genes controlled by the MYB-type transcription factors. Furthermore, the characterization of AtMYB60 has implications for the development of new varieties of lettuce and other commercially important plants with metabolic engineering approaches.

  7. YY1 Haploinsufficiency Causes an Intellectual Disability Syndrome Featuring Transcriptional and Chromatin Dysfunction

    DEFF Research Database (Denmark)

    Gabriele, Michele; Vulto-van Silfhout, Anneke T; Germain, Pierre-Luc

    2017-01-01

    Yin and yang 1 (YY1) is a well-known zinc-finger transcription factor with crucial roles in normal development and malignancy. YY1 acts both as a repressor and as an activator of gene expression. We have identified 23 individuals with de novo mutations or deletions of YY1 and phenotypic features ...

  8. ZNF322, a novel human C2H2 Krueppel-like zinc-finger protein, regulates transcriptional activation in MAPK signaling pathways

    International Nuclear Information System (INIS)

    Li Yongqing; Wang Yuequn; Zhang Caibo; Yuan Wuzhou; Wang Jun; Zhu Chuanbing; Chen Lei; Huang Wen; Zeng Weiqi; Wu Xiushan; Liu Mingyao

    2004-01-01

    Cardiac differentiation involves a cascade of coordinated gene expression that regulates cell proliferation and matrix protein formation in a defined temporal-spatial manner. The C 2 H 2 zinc finger-containing transcription factors have been implicated as critical regulators of multiple cardiac-expressed genes and are important for human heart development and diseases. Here we have identified and characterized a novel zinc-finger gene named ZNF322 using degenerated primers from a human embryo heart cDNA library. The gene contains four exons and spans 23.2 kb in chromosome 6p22.1 region, and transcribes a 2.7 kb mRNA that encodes a protein with 402 amino acid residues. The predicted protein contains 9 tandem C 2 H 2 -type zinc-finger motifs. Northern blot analysis shows that ZNF322 is expressed in every human tissue examined at adult stage and during embryonic developmental stages from 80 days to 24 weeks. When overexpressed in COS-7 cells, ZNF322-EGFP fusion protein is detected in the nucleus and cytoplasm. Reporter gene assays show that ZNF322 is a transcriptional activator. Furthermore, overexpression of ZNF322 in COS-7 cells activates the transcriptional activity of SRE and AP-1. Together, these results suggest that ZNF322 is a member of the zinc-finger transcription factor family and may act as a positive regulator in gene transcription mediated by the MAPK signaling pathways

  9. The role of Zic family zinc finger transcription factors in the proliferation and differentiation of retinal progenitor cells

    Energy Technology Data Exchange (ETDEWEB)

    Watabe, Yui [Division of Molecular and Developmental Biology, Institute of Medical Science, University of Tokyo (Japan); Department of Ophthalmology, Teikyo University School of Medicine, Tokyo (Japan); Division of Orthoptics, Teikyo University School of Medical Care and Technology, Tokyo (Japan); Baba, Yukihiro [Division of Molecular and Developmental Biology, Institute of Medical Science, University of Tokyo (Japan); Nakauchi, Hiromitsu [Division of Stem Cell Therapy, Center for Stem Cell Biology and Regenerative Medicine, Institute of Medical Science, University of Tokyo (Japan); Mizota, Atsushi [Department of Ophthalmology, Teikyo University School of Medicine, Tokyo (Japan); Watanabe, Sumiko, E-mail: sumiko@ims.u-tokyo.ac.jp [Division of Molecular and Developmental Biology, Institute of Medical Science, University of Tokyo (Japan)

    2011-11-11

    Highlights: Black-Right-Pointing-Pointer Zic transcription factors expressed early retinal progenitor cells. Black-Right-Pointing-Pointer Zics sustain proliferation activity of retinal progenitor cells. Black-Right-Pointing-Pointer Overexpression of Zic in retinal progenitors perturbed rod differentiation. Black-Right-Pointing-Pointer Fate determination to rod photoreceptor was not affected. -- Abstract: Members of the Zic family of zinc finger transcription factors play critical roles in a variety of developmental processes. Using DNA microarray analysis, we found that Zics are strongly expressed in SSEA-1-positive early retinal progenitors in the peripheral region of the mouse retina. Reverse-transcription polymerase chain reaction using mRNA from the retina at various developmental stages showed that Zic1 and Zic2 are expressed in the embryonic retina and then gradually disappear during retinal development. Zic3 is also expressed in the embryonic retina; its expression level slightly decreases but it is expressed until adulthood. We overexpressed Zic1, Zic2, or Zic3 in retinal progenitors at embryonic day 17.5 and cultured the retina as explants for 2 weeks. The number of rod photoreceptors was fewer than in the control, but no other cell types showed significant differences between control and Zic overexpressing cells. The proliferation activity of normal retinal progenitors decreased after 5 days in culture, as observed in normal in vivo developmental processes. However, Zic expressing retinal cells continued to proliferate at days 5 and 7, suggesting that Zics sustain the proliferation activities of retinal progenitor cells. Since the effects of Zic1, 2, and 3 are indistinguishable in terms of differentiation and proliferation of retinal progenitors, the redundant function of Zics in retinal development is suggested.

  10. Mutations in human immunodeficiency virus type 1 nucleocapsid protein zinc fingers cause premature reverse transcription.

    Science.gov (United States)

    Thomas, James A; Bosche, William J; Shatzer, Teresa L; Johnson, Donald G; Gorelick, Robert J

    2008-10-01

    Human immunodeficiency virus type 1 (HIV-1) requires that its genome be reverse transcribed into double-stranded DNA for productive infection of cells. This process requires not only reverse transcriptase but also the nucleocapsid protein (NC), which functions as a nucleic acid chaperone. Reverse transcription generally begins once the core of the virion enters the cytoplasm of a newly infected cell. However, some groups have reported the presence of low levels of viral DNA (vDNA) within particles prior to infection, the significance and function of which is controversial. We report here that several HIV-1 NC mutants, which we previously identified as being replication defective, contain abnormally high levels of intravirion DNA. These findings were further reinforced by the inability of these NC mutants to perform endogenous reverse transcription (ERT), in contrast to the readily measurable ERT activity in wild-type HIV-1. When either of the NC mutations is combined with a mutation that inactivates the viral protease, we observed a significant reduction in the amount of intravirion DNA. Interestingly, we also observed high levels of intravirion DNA in the context of wild-type NC when we delayed budding by means of a PTAP((-)) (Pro-Thr-Ala-Pro) mutation. Premature reverse transcription is most probably occurring before these mutant virions bud from producer cells, but we fail to see any evidence that the NC mutations alter the timing of Pr55(Gag) processing. Critically, our results also suggest that the presence of intravirion vDNA could serve as a diagnostic for identifying replication-defective HIV-1.

  11. The Solanum lycopersicum Zinc Finger2 Cysteine-2/Histidine-2 Repressor-Like Transcription Factor Regulates Development and Tolerance to Salinity in Tomato and Arabidopsis(1[W])

    Czech Academy of Sciences Publication Activity Database

    Hichri, I.; Muhovski, Y.; Žižková, Eva; Dobrev, Petre; Franco-Zorrilla, J.M.; Solano, R.; Lopez-Vidriero, I.; Motyka, Václav; Lutts, S.

    2014-01-01

    Roč. 164, č. 4 (2014), s. 1967-1990 ISSN 0032-0889 R&D Projects: GA ČR(CZ) GAP506/11/0774 Institutional support: RVO:61389030 Keywords : RICE ORYZA-SATIVA * AGROBACTERIUM -MEDIATED TRANSFORMATION * TARGET-SEQUENCE RECOGNITION Subject RIV: EF - Botanics Impact factor: 6.841, year: 2014

  12. Fear-of-intimacy-mediated zinc transport controls the function of zinc-finger transcription factors involved in myogenesis.

    Science.gov (United States)

    Carrasco-Rando, Marta; Atienza-Manuel, Alexandra; Martín, Paloma; Burke, Richard; Ruiz-Gómez, Mar

    2016-06-01

    Zinc is a component of one-tenth of all human proteins. Its cellular concentration is tightly regulated because its dyshomeostasis has catastrophic health consequences. Two families of zinc transporters control zinc homeostasis in organisms, but there is little information about their specific developmental roles. We show that the ZIP transporter Fear-of-intimacy (Foi) is necessary for the formation of Drosophila muscles. In foi mutants, myoblasts segregate normally, but their specification is affected, leading to the formation of a misshapen muscle pattern and distorted midgut. The observed phenotypes could be ascribed to the inactivation of specific zinc-finger transcription factors (ZFTFs), supporting the hypothesis that they are a consequence of intracellular depletion of zinc. Accordingly, foi phenotypes can be rescued by mesodermal expression of other ZIP members with similar subcellular localization. We propose that Foi acts mostly as a transporter to regulate zinc intracellular homeostasis, thereby impacting on the activity of ZFTFs that control specific developmental processes. Our results additionally suggest a possible explanation for the presence of large numbers of zinc transporters in organisms based on differences in ion transport specificity and/or degrees of activity among transporters. © 2016. Published by The Company of Biologists Ltd.

  13. Conversion of Human Fibroblasts to Stably Self-Renewing Neural Stem Cells with a Single Zinc-Finger Transcription Factor

    Directory of Open Access Journals (Sweden)

    Ebrahim Shahbazi

    2016-04-01

    Full Text Available Direct conversion of somatic cells into neural stem cells (NSCs by defined factors holds great promise for mechanistic studies, drug screening, and potential cell therapies for different neurodegenerative diseases. Here, we report that a single zinc-finger transcription factor, Zfp521, is sufficient for direct conversion of human fibroblasts into long-term self-renewable and multipotent NSCs. In vitro, Zfp521-induced NSCs maintained their characteristics in the absence of exogenous factor expression and exhibited morphological, molecular, developmental, and functional properties that were similar to control NSCs. In addition, the single-seeded induced NSCs were able to form NSC colonies with efficiency comparable with control NSCs and expressed NSC markers. The converted cells were capable of surviving, migrating, and attaining neural phenotypes after transplantation into neonatal mouse and adult rat brains, without forming tumors. Moreover, the Zfp521-induced NSCs predominantly expressed rostral genes. Our results suggest a facilitated approach for establishing human NSCs through Zfp521-driven conversion of fibroblasts.

  14. Genome-wide analysis of the DNA-binding with one zinc finger (Dof) transcription factor family in bananas.

    Science.gov (United States)

    Dong, Chen; Hu, Huigang; Xie, Jianghui

    2016-12-01

    DNA-binding with one finger (Dof) domain proteins are a multigene family of plant-specific transcription factors involved in numerous aspects of plant growth and development. In this study, we report a genome-wide search for Musa acuminata Dof (MaDof) genes and their expression profiles at different developmental stages and in response to various abiotic stresses. In addition, a complete overview of the Dof gene family in bananas is presented, including the gene structures, chromosomal locations, cis-regulatory elements, conserved protein domains, and phylogenetic inferences. Based on the genome-wide analysis, we identified 74 full-length protein-coding MaDof genes unevenly distributed on 11 chromosomes. Phylogenetic analysis with Dof members from diverse plant species showed that MaDof genes can be classified into four subgroups (StDof I, II, III, and IV). The detailed genomic information of the MaDof gene homologs in the present study provides opportunities for functional analyses to unravel the exact role of the genes in plant growth and development.

  15. Vascular plant one-zinc-finger protein 1/2 transcription factors regulate abiotic and biotic stress responses in Arabidopsis.

    Science.gov (United States)

    Nakai, Yusuke; Nakahira, Yoichi; Sumida, Hiroki; Takebayashi, Kosuke; Nagasawa, Yumiko; Yamasaki, Kanako; Akiyama, Masako; Ohme-Takagi, Masaru; Fujiwara, Sumire; Shiina, Takashi; Mitsuda, Nobutaka; Fukusaki, Eiichiro; Kubo, Yasuyuki; Sato, Masa H

    2013-03-01

    Plants adapt to abiotic and biotic stresses by activating abscisic acid-mediated (ABA) abiotic stress-responsive and salicylic acid-(SA) or jasmonic acid-mediated (JA) biotic stress-responsive pathways, respectively. Although the abiotic stress-responsive pathway interacts antagonistically with the biotic stress-responsive pathways, the mechanisms that regulate these pathways remain largely unknown. In this study, we provide insight into the function of vascular plant one-zinc-finger proteins (VOZs) that modulate various stress responses in Arabidopsis. The expression of many stress-responsive genes was changed in the voz1voz2 double mutant under normal growth conditions. Consistent with altered stress-responsive gene expression, freezing- and drought-stress tolerances were increased in the voz1voz2 double mutant. In contrast, resistance to a fungal pathogen, Colletotrichum higginsianum, and to a bacterial pathogen, Pseudomonas syringae, was severely impaired. Thus, impairing VOZ function simultaneously conferred increased abiotic tolerance and biotic stress susceptibility. In a chilling stress condition, both the VOZ1 and VOZ2 mRNA expression levels and the VOZ2 protein level gradually decreased. VOZ2 degradation during cold exposure was completely inhibited by the addition of the 26S proteasome inhibitor, MG132, a finding that suggested that VOZ2 degradation is dependent on the ubiquitin/26S proteasome system. In voz1voz2, ABA-inducible transcription factor CBF4 expression was enhanced significantly even under normal growth conditions, despite an unchanged endogenous ABA content. A finding that suggested that VOZs negatively affect CBF4 expression in an ABA-independent manner. These results suggest that VOZs function as both negative and positive regulators of the abiotic and biotic stress-responsive pathways, and control Arabidopsis adaptation to various stress conditions. © 2012 The Authors The Plant Journal © 2012 Blackwell Publishing Ltd.

  16. Activating human genes with zinc finger proteins, transcription activator-like effectors and CRISPR/Cas9 for gene therapy and regenerative medicine.

    Science.gov (United States)

    Gersbach, Charles A; Perez-Pinera, Pablo

    2014-08-01

    New technologies have recently been developed to control the expression of human genes in their native genomic context by engineering synthetic transcription factors that can be targeted to any DNA sequence. The ability to precisely regulate any gene as it occurs naturally in the genome provides a means to address a variety of diseases and disorders. This approach also circumvents some of the traditional challenges of gene therapy. In this editorial, we review the technologies that have enabled targeted human gene activation, including the engineering of transcription factors based on zinc finger proteins, transcription activator-like effectors and the CRISPR/Cas9 system. Additionally, we highlight examples in which these methods have been developed for therapeutic applications and discuss challenges and opportunities.

  17. Trigger finger

    Science.gov (United States)

    ... digit; Trigger finger release; Locked finger; Digital flexor tenosynovitis ... cut or hand Yellow or green drainage from the cut Hand pain or discomfort Fever If your trigger finger returns, call your surgeon. You may need another surgery.

  18. Zinc-fingers and homeoboxes 1 (ZHX1) binds DNA methyltransferase (DNMT) 3B to enhance DNMT3B-mediated transcriptional repression

    International Nuclear Information System (INIS)

    Kim, Sung-Hak; Park, Jinah; Choi, Moon-Chang; Kim, Hwang-Phill; Park, Jung-Hyun; Jung, Yeonjoo; Lee, Ju-Hee; Oh, Do-Youn; Im, Seock-Ah; Bang, Yung-Jue; Kim, Tae-You

    2007-01-01

    DNA methyltransferases (DNMT) 3B is a de novo DNMT that represses transcription independent of DNMT activity. In order to gain a better insight into DNMT3B-mediated transcriptional repression, we performed a yeast two-hybrid analysis using DNMT3B as a bait. Of the various binding candidates, ZHX1, a member of zinc-finger and homeobox protein, was found to interact with DNMT3B in vivo and in vitro. N-terminal PWWP domain of DNMT3B was required for its interaction with homeobox motifs of ZHX1. ZHX1 contains nuclear localization signal at C-terminal homeobox motif, and both ZHX1 and DNMT3B were co-localized in nucleus. Furthermore, we found that ZHX1 enhanced the transcriptional repression mediated by DNMT3B when DNMT3B is directly targeted to DNA. These results showed for First the direct linkage between DNMT and zinc-fingers homeoboxes protein, leading to enhanced gene silencing by DNMT3B

  19. PTB-associated splicing factor (PSF) functions as a repressor of STAT6-mediated IG{epsilon} gene transcription by recruitment of HDAC1

    DEFF Research Database (Denmark)

    Dong, Lijie; Zhang, Xinyu; Fu, Xiao

    2010-01-01

    of phosphorylation, and IL-4 stimulation increased tyrosine phosphorylation of PSF and STAT6. Functional analysis demonstrated that ectopic expression of PSF resulted in inhibition of STAT6-mediated gene transcriptional activation and mRNA expression of Ig heavy chain germline Ig ε, while knockdown of PSF increased......Regulation of transcription requires cooperation between sequence specific transcription factors and numerous coregulatory proteins. In IL-4/IL-13 signaling several coactivators for STAT6 have been identified, but the molecular mechanisms of STAT6-mediated gene transcription are still not fully...... understood. Here we identified by proteomic approach that PTB-associated splicing factor (PSF) interacts with STAT6. In cells the interaction required IL-4 stimulation and was observed both with endogenous and ectopically expressed proteins. The ligand dependency of the interaction suggested involvement...

  20. Decreased expression of Freud-1/CC2D1A, a transcriptional repressor of the 5-HT1A receptor, in the prefrontal cortex of subjects with major depression.

    Science.gov (United States)

    Szewczyk, Bernadeta; Albert, Paul R; Rogaeva, Anastasia; Fitzgibbon, Heidi; May, Warren L; Rajkowska, Grazyna; Miguel-Hidalgo, Jose J; Stockmeier, Craig A; Woolverton, William L; Kyle, Patrick B; Wang, Zhixia; Austin, Mark C

    2010-09-01

    Serotonin1A (5-HT(1A)) receptors are reported altered in the brain of subjects with major depressive disorder (MDD). Recent studies have identified transcriptional regulators of the 5-HT(1A) receptor and have documented gender-specific alterations in 5-HT(1A) transcription factor and 5-HT(1A) receptors in female MDD subjects. The 5' repressor element under dual repression binding protein-1 (Freud-1) is a calcium-regulated repressor that negatively regulates the 5-HT(1A) receptor gene. This study documented the cellular expression of Freud-1 in the human prefrontal cortex (PFC) and quantified Freud-1 protein in the PFC of MDD and control subjects as well as in the PFC of rhesus monkeys chronically treated with fluoxetine. Freud-1 immunoreactivity was present in neurons and glia and was co-localized with 5-HT(1A) receptors. Freud-1 protein level was significantly decreased in the PFC of male MDD subjects (37%, p=0.02) relative to gender-matched control subjects. Freud-1 protein was also reduced in the PFC of female MDD subjects (36%, p=0.18) but was not statistically significant. When the data was combined across genders and analysed by age, the decrease in Freud-1 protein level was greater in the younger MDD subjects (48%, p=0.01) relative to age-matched controls as opposed to older depressed subjects. Similarly, 5-HT(1A) receptor protein was significantly reduced in the PFC of the younger MDD subjects (48%, p=0.01) relative to age-matched controls. Adult male rhesus monkeys administered fluoxetine daily for 39 wk revealed no significant change in cortical Freud-1 or 5-HT(1A) receptor proteins compared to vehicle-treated control monkeys. Reduced protein expression of Freud-1 in MDD subjects may reflect dysregulation of this transcription factor, which may contribute to the altered regulation of 5-HT(1A) receptors observed in subjects with MDD. These data may also suggest that reductions in Freud-1 protein expression in the PFC may be associated with early onset of

  1. The TetR-type transcriptional repressor RolR from Corynebacterium glutamicum regulates resorcinol catabolism by binding to a unique operator, rolO.

    Science.gov (United States)

    Li, Tang; Zhao, Kexin; Huang, Yan; Li, Defeng; Jiang, Cheng-Ying; Zhou, Nan; Fan, Zheng; Liu, Shuang-Jiang

    2012-09-01

    The rol (designated for resorcinol) gene cluster rolRHMD is involved in resorcinol catabolism in Corynebacterium glutamicum, and RolR is the TetR-type regulator. In this study, we investigated how RolR regulated the transcription of the rol genes in C. glutamicum. The transcription start sites and promoters of rolR and rolHMD were identified. Quantitative reverse transcription-PCR and promoter activity analysis indicated that RolR negatively regulated the transcription of rolHMD and of its own gene. Further, a 29-bp operator rolO was located at the intergenic region of rolR and rolHMD and was identified as the sole binding site for RolR. It contained two overlapping inverted repeats and they were essential for RolR-binding. The binding of RolR to rolO was affected by resorcinol and hydroxyquinol, which are the starting compounds of resorcinol catabolic pathway. These two compounds were able to dissociate RolR-rolO complex, thus releasing RolR from the complex and derepressing the transcription of rol genes in C. glutamicum. It is proposed that the binding of RolR to its operator rolO blocks the transcription of rolHMD and of its own gene, thus negatively regulated resorcinol degradation in C. glutamicum.

  2. Papaya CpERF9 acts as a transcriptional repressor of cell-wall-modifying genes CpPME1/2 and CpPG5 involved in fruit ripening.

    Science.gov (United States)

    Fu, Chang-Chun; Han, Yan-Chao; Qi, Xiu-Ye; Shan, Wei; Chen, Jian-Ye; Lu, Wang-Jin; Kuang, Jian-Fei

    2016-11-01

    CpERF9 controls papaya fruit ripening through transcriptional repression of cell-wall-modifying genes CpPME1/2 and CpPG5 by directly binding to their promoters. Papaya fruit ripening is an intricate and highly coordinated developmental process which is controlled by the action of ethylene and expression of numerous ethylene-responsive genes. Ethylene response factors (ERFs) representing the last regulators of ethylene-signaling pathway determine the specificities of ethylene response. However, knowledge concerning the transcriptional controlling mechanism of ERF-mediated papaya fruit ripening is limited. In the present work, a gene-encoding AP2/ERF protein with two ERF-associated amphiphilic repression (EAR) motifs, named CpERF9, was characterized from papaya fruit. CpERF9 was found to localize in nucleus, and possess transcriptional repression ability. CpERF9 expression steadily decreased during papaya fruit ripening, while several genes encoding pectin methylesterases (PMEs) and polygalacturonases (PGs), such as CpPME1/2 and CpPG5, were gradually increased, paralleling the decline of fruit firmness. Electrophoretic mobility shift assay (EMSA) demonstrated a specific binding of CpERF9 to promoters of CpPME1/2 and CpPG5, via the GCC-box motif. Transient expression of CpERF9 in tobacco repressed CpPME1/2 and CpPG5 promoter activities, which was depended on two EAR motifs of CpERF9 protein. Taken together, these findings suggest that papaya CpERF9 may act as a transcriptional repressor of several cell-wall modifying genes, such as CpPME1/2 and CpPG5, via directly binding to their promoters.

  3. The ascorbate peroxidase APX1 is a direct target of a zinc finger transcription factor ZFP36 and a late embryogenesis abundant protein OsLEA5 interacts with ZFP36 to co-regulate OsAPX1 in seed germination in rice.

    Science.gov (United States)

    Huang, Liping; Jia, Jing; Zhao, Xixi; Zhang, MengYao; Huang, Xingxiu; E Ji; Ni, Lan; Jiang, Mingyi

    2018-01-01

    Seed germination is a vital developmental process. Abscisic acid (ABA) is an essential repressor of seed germination, while ROS (reactive oxygen species) also plays a vital role in regulating seed germination. ABA could inhibit the production of ROS in seed germination, but the mechanism of ABA reduced ROS production in seed germination was hitherto unknown. Here, by ChIP (chromatin immunoprecipitation)-seq, we found that ZFP36, a rice zinc finger transcription factor, could directly bind to the promoter of OsAPX1, coding an ascorbate peroxidase (APX) which has the most affinity for H 2 O 2 (substrate; a type of ROS), and act as a transcriptional activator of OsAPX1 promoter. Moreover, ZFP36 could interact with a late embryogenesis abundant protein OsLEA5 to co-regulate the promoter activity of OsAPX1. The seed germination is highly inhibited in ZFP36 overexpression plants under ABA treatment, while an RNA interference (RNAi) mutant of OsLEA5 rice seeds were less sensitive to ABA, and exogenous ASC (ascorbate acid) could alleviate the inhibition induced by ABA. Thus, our conclusion is that OsAPX1 is a direct target of ZFP36 and OsLEA5 could interact with ZFP36 to co-regulate ABA-inhibited seed germination by controlling the expression of OsAPX1. Copyright © 2017. Published by Elsevier Inc.

  4. Characterization of E2F8, a novel E2F-like cell-cycle regulated repressor of E2F-activated transcription

    DEFF Research Database (Denmark)

    Christensen, Jesper; Cloos, Paul; Toftegaard, Ulla

    2005-01-01

    The E2F family of transcription factors are downstream effectors of the retinoblastoma protein, pRB, pathway and are essential for the timely regulation of genes necessary for cell-cycle progression. Here we describe the characterization of human and murine E2F8, a new member of the E2F family...

  5. The Transcriptional Repressor, MtrR, of the mtrCDE Efflux Pump Operon of Neisseria gonorrhoeae Can Also Serve as an Activator of “off Target” Gene (glnE Expression

    Directory of Open Access Journals (Sweden)

    Paul J. T. Johnson

    2015-06-01

    Full Text Available MtrR is a well-characterized repressor of the Neisseria gonorrhoeae mtrCDE efflux pump operon. However, results from a previous transcriptional profiling study suggested that MtrR also represses or activates expression of at least sixty genes outside of the mtr locus. Evidence that MtrR can directly repress so-called “off target” genes has previously been reported; in particular, MtrR was shown to directly repress glnA, which encodes glutamine synthetase. In contrast, evidence for the ability of MtrR to directly activate expression of gonococcal genes has been lacking; herein, we provide such evidence. We now report that MtrR has the ability to directly activate expression of glnE, which encodes the dual functional adenyltransferase/deadenylase enzyme GlnE that modifies GlnA resulting in regulation of its role in glutamine biosynthesis. With its capacity to repress expression of glnA, the results presented herein emphasize the diverse and often opposing regulatory properties of MtrR that likely contributes to the overall physiology and metabolism of N. gonorrhoeae.

  6. Zinc finger artificial transcription factor-based nearest inactive analogue/nearest active analogue strategy used for the identification of plant genes controlling homologous recombination.

    Science.gov (United States)

    Jia, Qi; van Verk, Marcel C; Pinas, Johan E; Lindhout, Beatrice I; Hooykaas, Paul J J; van der Zaal, Bert J

    2013-12-01

    In previous work, we selected a particular transcription factor, designated VP16-HRU, from a pool of zinc finger artificial transcription factors (ZF-ATFs) used for genome interrogation. When expressed in Arabidopsis thaliana under control of the ribosomal protein S5A promoter, the RPS5A::VP16-HRU construct led to a 200- to 300-fold increase in the frequency of somatic intrachromosomal homologous recombination (iHR). Because the expression of each ZF-ATF leads to a large number of transcriptional changes, we designed a strategy employing a collection of structurally similar ZF-ATFs to filter out the transcriptional changes relevant to the phenotype by deep sequencing. In that manner, 30 transcripts were found to be consistently induced in plants with enhanced homologous recombination (HR). For 25 of the cognate genes, their effect on the HR process was assessed using cDNA/gDNA expression constructs. For three genes, ectopic expression indeed led to enhanced iHR frequencies, albeit much lower than the frequency observed when a HR-inducing ZF-ATF was present. Altogether, our data demonstrate that despite the large number of transcriptional changes brought about by individual ZF-ATFs, causal changes can be identified. In our case, the picture emerged that a natural regulatory switch for iHR does not exist but that ZF-ATFs-like VP16-HRU act as an ectopic master switch, orchestrating the timely expression of a set of plant genes that each by themselves only have modest effects, but when acting together support an extremely high iHR frequency. © 2013 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

  7. Structural Insight on the Mechanism of Regulation of the MarR Family of Proteins: High-Resolution Crystal Structure of a Transcriptional Repressor from Methanobacterium thermoautotrophicum

    Energy Technology Data Exchange (ETDEWEB)

    Saridakis, Vivian; Shahinas, Dea; Xu, Xiaohui; Christendat, Dinesh (York); (Toronto); (CG)

    2008-03-31

    Transcriptional regulators belonging to the MarR family are characterized by a winged-helix DNA binding domain. These transcriptional regulators regulate the efflux and influx of phenolic agents in bacteria and archaea. In Escherichia coli, MarR regulates the multiple antibiotic resistance operon and its inactivation produces a multiple antibiotic resistance phenotype. In some organisms, active efflux of drug compounds will produce a drug resistance phenotype, whereas in other organisms, active influx of chlorinated hydrocarbons results in their rapid degradation. Although proteins in the MarR family are regulators of important biological processes, their mechanism of action is not well understood and structural information about how phenolic agents regulate the activity of these proteins is lacking. This article presents the three-dimensional structure of a protein of the MarR family, MTH313, in its apo form and in complex with salicylate, a known inactivator. A comparison of these two structures indicates that the mechanism of regulation involves a large conformational change in the DNA binding lobe. Electrophoretic mobility shift assay and biophysical analyses further suggest that salicylate inactivates MTH313 and prevents it from binding to its promoter region.

  8. The Sweet Potato NAC-Domain Transcription Factor IbNAC1 Is Dynamically Coordinated by the Activator IbbHLH3 and the Repressor IbbHLH4 to Reprogram the Defense Mechanism against Wounding

    Science.gov (United States)

    Chen, Shi-Peng; Kuo, Chih-Hsien; Lu, Hsueh-Han; Lo, Hui-Shan; Yeh, Kai-Wun

    2016-01-01

    IbNAC1 is known to activate the defense system by reprogramming a genetic network against herbivory in sweet potato. This regulatory activity elevates plant defense potential but relatively weakens plants by IbNAC1-mediated JA response. The mechanism controlling IbNAC1 expression to balance plant vitality and survival remains unclear. In this study, a wound-responsive G-box cis-element in the IbNAC1 promoter from -1484 to -1479 bp was identified. From a screen of wound-activated transcriptomic data, one transcriptional activator, IbbHLH3, and one repressor, IbbHLH4, were selected that bind to and activate or repress, respectively, the G-box motif in the IbNAC1 promoter to modulate the IbNAC1-mediated response. In the early wound response, the IbbHLH3-IbbHLH3 protein complex binds to the G-box motif to activate IbNAC1 expression. Thus, an elegant defense network is activated against wounding stress. Until the late stages of wounding, IbbHLH4 interacts with IbbHLH3, and the IbbHLH3-IbbHLH4 heterodimer competes with the IbbHLH3-IbbHLH3 complex to bind the G-box and suppress IbNAC1 expression and timely terminates the defense network. Moreover, the JAZs and IbEIL1 proteins interact with IbbHLH3 to repress the transactivation function of IbbHLH3 in non-wounded condition, but their transcription is immediately inhibited upon early wounding. Our work provides a genetic model that accurately switches the regulatory mechanism of IbNAC1 expression to adjust wounding physiology and represents a delicate defense regulatory network in plants. PMID:27780204

  9. The histone-like protein H-NS acts as a transcriptional repressor for expression of the anaerobic and growth phase activator AppY of Escherichia coli

    DEFF Research Database (Denmark)

    Atlung, Tove; Sund, Susanne; Olesen, Kirsten

    1996-01-01

    The transcriptional activator AppY is required for anaerobic and stationary phase induction of the cyx-appA and hya operons of Escherichia coli, and the expression of the appY gene itself is induced by these environmental conditions. The sequence of the appY gene and its promoter region is unusua...... that purified H-NS protein bound with high affinity to two different segments of the appY promoter region. The role of H-NS in the AppY regulatory cascade is discussed and compared with its function in the regulatory cascades of the AppY homologs CfaD and VirF....

  10. Finger pain

    Science.gov (United States)

    Pain - finger ... Nearly everyone has had finger pain at some time. You may have: Tenderness Burning Stiffness Numbness Tingling Coldness Swelling Change in skin color Redness Many conditions, such ...

  11. The ken and barbie gene encoding a putative transcription factor with a BTB domain and three zinc finger motifs functions in terminalia development of Drosophila.

    Science.gov (United States)

    Lukacsovich, Tamas; Yuge, Kazuya; Awano, Wakae; Asztalos, Zoltan; Kondo, Shunzo; Juni, Naoto; Yamamoto, Daisuke

    2003-10-01

    Mutations in the ken and barbie locus are accompanied by the malformation of terminalia in adult Drosophila. Male and female genitalia often remain inside the body, and the same portions of genitalia and analia are missing in a fraction of homozygous flies. Rotated and/or duplicated terminalia are also observed. Terminalia phenotypes are enhanced by mutations in the gap gene tailless, the homeobox gene caudal, and the decapentaplegic gene that encodes a TGFbeta-like morphogen. The ken and barbie gene encodes a protein with three CCHH-type zinc finger motifs that are conserved in several transcription factors such as Krüppel and BCL-6. All defects in ken and barbie mutants are fully rescued by the expression of a wild-type genomic construct, which establishes the causality between phenotypes and the gene. Copyright 2003 Wiley-Liss, Inc.

  12. The Mg-chelatase H subunit of Arabidopsis antagonizes a group of WRKY transcription repressors to relieve ABA-responsive genes of inhibition.

    Science.gov (United States)

    Shang, Yi; Yan, Lu; Liu, Zhi-Qiang; Cao, Zheng; Mei, Chao; Xin, Qi; Wu, Fu-Qing; Wang, Xiao-Fang; Du, Shu-Yuan; Jiang, Tao; Zhang, Xiao-Feng; Zhao, Rui; Sun, Hai-Li; Liu, Rui; Yu, Yong-Tao; Zhang, Da-Peng

    2010-06-01

    The phytohormone abscisic acid (ABA) plays a vital role in plant development and response to environmental challenges, but the complex networks of ABA signaling pathways are poorly understood. We previously reported that a chloroplast protein, the magnesium-protoporphyrin IX chelatase H subunit (CHLH/ABAR), functions as a receptor for ABA in Arabidopsis thaliana. Here, we report that ABAR spans the chloroplast envelope and that the cytosolic C terminus of ABAR interacts with a group of WRKY transcription factors (WRKY40, WRKY18, and WRKY60) that function as negative regulators of ABA signaling in seed germination and postgermination growth. WRKY40, a central negative regulator, inhibits expression of ABA-responsive genes, such as ABI5. In response to a high level of ABA signal that recruits WRKY40 from the nucleus to the cytosol and promotes ABAR-WRKY40 interaction, ABAR relieves the ABI5 gene of inhibition by repressing WRKY40 expression. These findings describe a unique ABA signaling pathway from the early signaling events to downstream gene expression.

  13. The Mg-Chelatase H Subunit of Arabidopsis Antagonizes a Group of WRKY Transcription Repressors to Relieve ABA-Responsive Genes of Inhibition[W][OA

    Science.gov (United States)

    Shang, Yi; Yan, Lu; Liu, Zhi-Qiang; Cao, Zheng; Mei, Chao; Xin, Qi; Wu, Fu-Qing; Wang, Xiao-Fang; Du, Shu-Yuan; Jiang, Tao; Zhang, Xiao-Feng; Zhao, Rui; Sun, Hai-Li; Liu, Rui; Yu, Yong-Tao; Zhang, Da-Peng

    2010-01-01

    The phytohormone abscisic acid (ABA) plays a vital role in plant development and response to environmental challenges, but the complex networks of ABA signaling pathways are poorly understood. We previously reported that a chloroplast protein, the magnesium-protoporphyrin IX chelatase H subunit (CHLH/ABAR), functions as a receptor for ABA in Arabidopsis thaliana. Here, we report that ABAR spans the chloroplast envelope and that the cytosolic C terminus of ABAR interacts with a group of WRKY transcription factors (WRKY40, WRKY18, and WRKY60) that function as negative regulators of ABA signaling in seed germination and postgermination growth. WRKY40, a central negative regulator, inhibits expression of ABA-responsive genes, such as ABI5. In response to a high level of ABA signal that recruits WRKY40 from the nucleus to the cytosol and promotes ABAR–WRKY40 interaction, ABAR relieves the ABI5 gene of inhibition by repressing WRKY40 expression. These findings describe a unique ABA signaling pathway from the early signaling events to downstream gene expression. PMID:20543028

  14. Involvement of transcription repressor Snail in the regulation of human telomerase reverse transcriptase (hTERT) by transforming growth factor-β.

    Science.gov (United States)

    Yoo, Young-Sun; Park, Seoyoung; Gwak, Jungsug; Ju, Bong Gun; Oh, Sangtaek

    2015-09-11

    Human telomerase reverse transcriptase (hTERT), a catalytic subunit of telomerase, is the primary determinant for telomerase enzyme activity, which has been associated with cellular immortality. Expression of the hTERT gene is regulated by various extracellular (external) stimuli and is aberrantly up-regulated in more than 90% of cancers. Here we show that hTERT gene expression was repressed in response to transforming growth factor-β (TGF-β) by a mechanism dependent on transcription factors Snail and c-Myc. TGF-β activated Snail and down-regulated c-Myc gene expression. In addition, ectopic expression of Snail strongly inhibited hTERT promoter activity, although co-expression of c-Myc abrogated this effect. Chromatin immunoprecipitation (ChIP) analysis revealed that TGF-β decreased c-Myc occupancy and dramatically increased recruitment of Snail to the E-box motifs of the hTERT promoter, thereby repressing hTERT expression. Our findings suggest a dynamic alteration in hTERT promoter occupancy by Snail and c-Myc is the mechanistic basis for TGF-β-mediated regulation of hTERT. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. The brain-specific neural zinc finger transcription factor 2b (NZF-2b/7ZFMyt1 suppresses cocaine self-administration in rats

    Directory of Open Access Journals (Sweden)

    Vijay Chandrasekar

    2010-04-01

    Full Text Available Brain-specific neural-zinc-finger transcription factor-2b (NZF2b/7ZFMyt1 is induced in the mesolimbic dopaminergic region after chronic cocaine exposure and lentiviral-mediated expression of NZF2b/7ZFMyt1 in the nucleus accumbens results in decreased locomotor activity (Chandrasekar and Dreyer, 2009. In this study the role of NZF2b/7ZFMyt1 in active cocaine seeking and of its interaction with histone deacetylase on the altered behavior has been observed. Localized expression of NZF2b/7ZFMyt1 in the nucleus accumbens resulted in attenuated cocaine self-administration, whereas silencing this transcription factor with lentiviruses expressing siRNAs increased the animal′s motivation to self-infuse cocaine. Low doses of sodium butyrate, a potent inhibitor of histone deacetylase, were sufficient to reverse the NZF2b/7ZFMyt1-mediated decrease in cocaine self-administration. NZF2b/7ZFMyt1 expression resulted in strong induction of transcription factors REST1 and NAC1 and of the dopamine D2 receptor, with concomitant inhibition of BDNF and its receptor TrkB. We show that NZF2b/7ZFMyt1 colocalizes with histone deacetylase-2 (HDAC2, probably overcoming the suppression of transcriptional activity caused by Lingo1. These findings show that molecular adaptations mediated by NZF2b/7ZFMyt1 expression possibly lead to decreased responsiveness to the reinforcing properties of cocaine and play a prominent role in affecting the behavioral changes induced by the drug.

  16. Klf1, a C2H2 zinc finger-transcription factor, is required for cell wall maintenance during long-term quiescence in differentiated G0 phase.

    Directory of Open Access Journals (Sweden)

    Mizuki Shimanuki

    Full Text Available Fission yeast, Schizoaccharomyces pombe, is a model for studying cellular quiescence. Shifting to a medium that lacks a nitrogen-source induces proliferative cells to enter long-term G0 quiescence. Klf1 is a Krüppel-like transcription factor with a 7-amino acid Cys2His2-type zinc finger motif. The deletion mutant, ∆klf1, normally divides in vegetative medium, but proliferation is not restored after long-term G0 quiescence. Cell biologic, transcriptomic, and metabolomic analyses revealed a unique phenotype of the ∆klf1 mutant in quiescence. Mutant cells had diminished transcripts related to signaling molecules for switching to differentiation; however, proliferative metabolites for cell-wall assembly and antioxidants had significantly increased. Further, the size of ∆klf1 cells increased markedly during quiescence due to the aberrant accumulation of Calcofluor-positive, chitin-like materials beneath the cell wall. After 4 weeks of quiescence, reversible proliferation ability was lost, but metabolism was maintained. Klf1 thus plays a role in G0 phase longevity by enhancing the differentiation signal and suppressing metabolism for growth. If Klf1 is lost, S. pombe fails to maintain a constant cell size and normal cell morphology during quiescence.

  17. A Zinc-Finger-Family Transcription Factor, AbVf19, Is Required for the Induction of a Gene Subset Important for Virulence in Alternaria brassicicola

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, Akhil [Univ. of Hawaii, Manoa, HI (United States); Ohm, Robin A. [USDOE Joint Genome Inst., Walnut Creek, CA (United States); Oxiles, Lindsay [Univ. of Hawaii, Manoa, HI (United States); Brooks, Fred [Univ. of Hawaii, Manoa, HI (United States); Lawrence, Christopher B. [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Grigoriev, Igor V. [USDOE Joint Genome Inst., Walnut Creek, CA (United States); Cho, Yangrae [Univ. of Hawaii, Manoa, HI (United States)

    2011-10-26

    Alternaria brassicicola is a successful saprophyte and necrotrophic plant pathogen with a broad host range within the family Brassicaceae. It produces secondary metabolites that marginally affect virulence. Cell wall degrading enzymes (CDWE) have been considered important for pathogenesis but none of them individually have been identified as significant virulence factors in A. brassicicola. In this study, knockout mutants of a gene, AbVf19, were created and produced considerably smaller lesions than the wild type on inoculated host plants. The presence of tandem zinc-finger domains in the predicted amino acid sequence and nuclear localization of AbVf19- reporter protein suggested that it was a transcription factor. Gene expression comparisons using RNA-seq identified 74 genes being downregulated in the mutant during a late stage of infection. Among the 74 downregulated genes, 28 were putative CWDE genes. These were hydrolytic enzyme genes that composed a small fraction of genes within each family of cellulases, pectinases, cutinases, and proteinases. The mutants grew slower than the wild type on an axenic medium with pectin as a major carbon source. This study demonstrated the existence and the importance of a transcription factor that regulates a suite of genes that are important for decomposing and utilizing plant material during the late stage of plant infection.

  18. Cloning and characterization of a novel human zinc finger gene, hKid3, from a C2H2-ZNF enriched human embryonic cDNA library

    International Nuclear Information System (INIS)

    Gao Li; Sun Chong; Qiu Hongling; Liu Hui; Shao Huanjie; Wang Jun; Li Wenxin

    2004-01-01

    To investigate the zinc finger genes involved in human embryonic development, we constructed a C 2 H 2 -ZNF enriched human embryonic cDNA library, from which a novel human gene named hKid3 was identified. The hKid3 cDNA encodes a 554 amino acid protein with an amino-terminal KRAB domain and 11 carboxyl-terminal C 2 H 2 zinc finger motifs. Northern blot analysis indicates that two hKid3 transcripts of 6 and 8.5 kb express in human fetal brain and kidney. The 6 kb transcript can also be detected in human adult brain, heart, and skeletal muscle while the 8.5 kb transcript appears to be embryo-specific. GFP-fused hKid3 protein is localized to nuclei and the ZF domain is necessary and sufficient for nuclear localization. To explore the DNA-binding specificity of hKid3, an oligonucleotide library was selected by GST fusion protein of hKid3 ZF domain, and the consensus core sequence 5'-CCAC-3' was evaluated by competitive electrophoretic mobility shift assay. Moreover, The KRAB domain of hKid3 exhibits transcription repressor activity when tested in GAL4 fusion protein assay. These results indicate that hKid3 may function as a transcription repressor with regulated expression pattern during human development of brain and kidney

  19. The retinoblastoma protein as a transcriptional repressor

    DEFF Research Database (Denmark)

    Helin, K; Ed, H

    1993-01-01

    The retinoblastoma protein (pRB) is one of the best-studied tumour suppressor gene products. Its loss during the genesis of many human tumours, its inactivation by several DNA tumour virus oncoproteins, and its ability to inhibit cell growth when introduced into dividing cells all suggest that p...

  20. VOZ; isolation and characterization of novel vascular plant transcription factors with a one-zinc finger from Arabidopsis thaliana.

    Science.gov (United States)

    Mitsuda, Nobutaka; Hisabori, Toru; Takeyasu, Kunio; Sato, Masa H

    2004-07-01

    A 38-bp pollen-specific cis-acting region of the AVP1 gene is involved in the expression of the Arabidopsis thaliana V-PPase during pollen development. Here, we report the isolation and structural characterization of AtVOZ1 and AtVOZ2, novel transcription factors that bind to the 38-bp cis-acting region of A. thaliana V-PPase gene, AVP1. AtVOZ1 and AtVOZ2 show 53% amino acid sequence similarity. Homologs of AtVOZ1 and AtVOZ2 are found in various vascular plants as well as a moss, Physcomitrella patens. Promoter-beta-glucuronidase reporter analysis shows that AtVOZ1 is specifically expressed in the phloem tissue and AtVOZ2 is strongly expressed in the root. In vivo transient effector-reporter analysis in A. thaliana suspension-cultured cells demonstrates that AtVOZ1 and AtVOZ2 function as transcriptional activators in the Arabidopsis cell. Two conserved regions termed Domain-A and Domain-B were identified from an alignment of AtVOZ proteins and their homologs of O. sativa and P. patens. AtVOZ2 binds as a dimer to the specific palindromic sequence, GCGTNx7ACGC, with Domain-B, which is comprised of a functional novel zinc coordinating motif and a conserved basic region. Domain-B is shown to function as both the DNA-binding and the dimerization domains of AtVOZ2. From highly the conservative nature among all identified VOZ proteins, we conclude that Domain-B is responsible for the DNA binding and dimerization of all VOZ-family proteins and designate it as the VOZ-domain.

  1. Genome-wide analysis and expression profiling of DNA-binding with one zinc finger (Dof) transcription factor family in potato.

    Science.gov (United States)

    Venkatesh, Jelli; Park, Se Won

    2015-09-01

    DNA-binding with one finger (Dof) domain proteins are a multigene family of plant-specific transcription factors involved in numerous aspects of plant growth and development. Here, we report a genome-wide search for Solanum tuberosum Dof (StDof) genes and their expression profiles at various developmental stages and in response to various abiotic stresses. In addition, a complete overview of Dof gene family in potato is presented, including the gene structures, chromosomal locations, cis-regulatory elements, conserved protein domains, and phylogenetic inferences. Based on the genome-wide analysis, we identified 35 full-length protein-coding StDof genes, unevenly distributed on 10 chromosomes. Phylogenetic analysis with Dof members from diverse plant species showed that StDof genes can be classified into four subgroups (StDofI, II, III, and IV). qPCR expression analysis of StDof gene transcripts showed the distinct expression patterns of StDof genes in various potato organs, and tuber developmental stages analyzed. Many StDof genes were upregulated in response to drought, salinity, and ABA treatments. Overall, the StDof gene expression pattern and the number of over-represented cis-acting elements in the promoter regions of the StDof genes indicate that most of the StDof genes have redundant functions. The detailed genomic information and expression profiles of the StDof gene homologs in the present study provide opportunities for functional analyses to unravel the genes' exact role in plant growth and development as well as in abiotic stress tolerance. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  2. Restriction of IL-22-producing T cell responses and differential regulation of regulatory T cell compartments by zinc finger transcription factor Ikaros.

    Science.gov (United States)

    Heller, Jennifer J; Schjerven, Hilde; Li, Shiyang; Lee, Aileen; Qiu, Ju; Chen, Zong-Ming E; Smale, Stephen T; Zhou, Liang

    2014-10-15

    Proper immune responses are needed to control pathogen infection at mucosal surfaces. IL-22-producing CD4(+) T cells play an important role in controlling bacterial infection in the gut; however, transcriptional regulation of these cells remains elusive. In this study, we show that mice with targeted deletion of the fourth DNA-binding zinc finger of the transcription factor Ikaros had increased IL-22-producing, but not IL-17-producing, CD4(+) T cells in the gut. Adoptive transfer of CD4(+) T cells from these Ikaros-mutant mice conferred enhanced mucosal immunity against Citrobacter rodentium infection. Despite an intact in vivo thymic-derived regulatory T cell (Treg) compartment in these Ikaros-mutant mice, TGF-β, a cytokine well known for induction of Tregs, failed to induce Foxp3 expression in Ikaros-mutant CD4(+) T cells in vitro and, instead, promoted IL-22. Aberrant upregulation of IL-21 in CD4(+) T cells expressing mutant Ikaros was responsible, at least in part, for the enhanced IL-22 expression in a Stat3-dependent manner. Genetic analysis using compound mutations further demonstrated that the aryl hydrocarbon receptor, but not RORγt, was required for aberrant IL-22 expression by Ikaros-mutant CD4(+) T cells, whereas forced expression of Foxp3 was sufficient to inhibit this aberrant cytokine production. Together, our data identified new functions for Ikaros in maintaining mucosal immune homeostasis by restricting IL-22 production by CD4(+) T cells. Copyright © 2014 by The American Association of Immunologists, Inc.

  3. A conserved function of the zinc finger transcription factor Sp8/9 in allometric appendage growth in the milkweed bug Oncopeltus fasciatus.

    Science.gov (United States)

    Schaeper, Nina D; Prpic, Nikola-Michael; Wimmer, Ernst A

    2009-08-01

    The genes encoding the closely related zinc finger transcription factors Buttonhead (Btd) and D-Sp1 are expressed in the developing limb primordia of Drosophila melanogaster and are required for normal growth of the legs. The D-Sp1 homolog of the red flour beetle Tribolium castaneum, Sp8 (appropriately termed Sp8/9), is also required for the proper growth of the leg segments. Here we report on the isolation and functional study of the Sp8/9 gene from the milkweed bug Oncopeltus fasciatus. We show that Sp8/9 is expressed in the developing appendages throughout development and that the downregulation of Sp8/9 via RNAi leads to antennae, rostrum, and legs with shortened and fused segments. This supports a conserved role of Sp8/9 in allometric leg segment growth. However, all leg segments including the claws are present and the expression of the leg genes Distal-less, dachshund, and homothorax are proportionally normal, thus providing no evidence for a role of Sp8/9 in appendage specification.

  4. Ni2+-based immobilized metal ion affinity chromatography of lactose operon repressor protein from Escherichia coli.

    Science.gov (United States)

    Velkov, Tony; Jones, Alun; Lim, Maria L R

    2008-01-01

    A two-step chromatographic sequence is described for the purification of native lactose operon repressor protein from Escherichia coli cells. The first step involves Ni(2+)-based immobilized metal ion affinity chromatography of the soluble cytoplasmic extract. This method provides superior speed, resolution and yield than the established phosphocellulose cation-exchange chromatographic procedure. Anion-exchange chromatography is used for further purification to >95% purity. The identity and purity of the lactose repressor protein were demonstrated using sodium dodecylsulphate polyacrylamide electrophoresis, crystallization, tryptic finger-printing mass spectrometry, and inducer binding assays. The purified lac repressor exhibited inducer sensitivity for operator DNA binding and undergoes a conformational change upon inducer binding. By all these extensive biochemical criteria, the purified protein behaves exactly as that described for the Escherichia coli lactose operon repressor.

  5. Annexin A2 and zinc finger transcription factor Snail expression in glioma tissue and the regulating effect of corresponding siRNA on glioma cells

    Directory of Open Access Journals (Sweden)

    Zheng-Hai Deng

    2016-12-01

    Full Text Available Objective: To study the Annexin A2 and zinc finger transcription factor Snail expression in glioma tissue and the regulating effect of corresponding siRNA on glioma cells. Methods: Glioma and peri-tumor tissue were collected to determine AnnexinA2 and Snail expression; glioma cell lines U373-MG were cultured and transfected with AnnexinA2, Snail and NC siRNA, and then the cell viability, number of migrating and invading cells as well as the expression levels of proliferation and epithelial-mesenchymal transition genes were detected. Results: AnnexinA2 and Snail mRNA levels in glioma tissues were significantly higher than those in peri-tumor tissues; cell viability as well as Ras, Raf, MEK and ERK mRNA levels of AnnexinA2-siRNA group was significantly lower than those of NC-siRNA group, and the migrating cell number and invading cell number as well as E-cadherin, N-cadherin, Vimentin and α-SMA mRNA levels were not significantly different from those of NC-siRNA group; migrating cell number and invading cell number as well as N-cadherin, Vimentin and α-SMA mRNA levels of Snail-siRNA group were significantly lower than those of NC-siRNA group, E-cadherin mRNA level was significantly higher than that of NC-siRNA group, and the cell viability as well as Ras, Raf, MEK and ERK mRNA levels were not significantly different from those of NC-siRNA group. Conclusions: AnnexinA2 and Snail expression levels significantly increase in glioma tissues, highly expressed AnnexinA2 can promote cell proliferation and highly expressed Snail can promote epithelial-mesenchymal transition.

  6. The Histone-H3K4-Specific Demethylase KDM5B Binds to Its Substrate and Product through Distinct PHD Fingers

    Directory of Open Access Journals (Sweden)

    Brianna J. Klein

    2014-01-01

    Full Text Available The histone lysine demethylase KDM5B regulates gene transcription and cell differentiation and is implicated in carcinogenesis. It contains multiple conserved chromatin-associated domains, including three PHD fingers of unknown function. Here, we show that the first and third, but not the second, PHD fingers of KDM5B possess histone binding activities. The PHD1 finger is highly specific for unmodified histone H3 (H3K4me0, whereas the PHD3 finger shows preference for the trimethylated histone mark H3K4me3. RNA-seq analysis indicates that KDM5B functions as a transcriptional repressor for genes involved in inflammatory responses, cell proliferation, adhesion, and migration. Biochemical analysis reveals that KDM5B associates with components of the nucleosome remodeling and deacetylase (NuRD complex and may cooperate with the histone deacetylase 1 (HDAC1 in gene repression. KDM5B is downregulated in triple-negative breast cancer relative to estrogen-receptor-positive breast cancer. Overexpression of KDM5B in the MDA-MB 231 breast cancer cells suppresses cell migration and invasion, and the PHD1-H3K4me0 interaction is essential for inhibiting migration. These findings highlight tumor-suppressive functions of KDM5B in triple-negative breast cancer cells and suggest a multivalent mechanism for KDM5B-mediated transcriptional regulation.

  7. EBF1 acts as a powerful repressor of Blimp-1 gene expression in immature B cells.

    Science.gov (United States)

    Kikuchi, Hidehiko; Nakayama, Masami; Takami, Yasunari; Kuribayashi, Futoshi; Nakayama, Tatsuo

    2012-06-15

    The transcription factor, early B cell factor 1 (EBF1) with an atypical zinc-finger and helix-loop-helix motif, is essential for development and differentiation of lymphocytes. In mice, EBF1 is involved in the generation of pre-pro B cells (the first specified progenitors of B cells) from common lymphoid progenitors (CLPs) and transcription regulations of various genes involved in B cell-development, for instance, mb-1 and Pax5. During B lymphopoiesis, interestingly, EBF1 is detected throughout from CLPs to mature B cells. However, in immature B cells, the physiological role of EBF1 remains to be elucidated. Here, by analyzing EBF1-deficient DT40 cells, EBF1(-/-), generated by us, we show that EBF1-deficiency caused significant increases (to ∼800%) in both mRNA and protein levels of B lymphocyte-induced maturation protein-1 (Blimp-1), the master gene for plasma cell differentiation. In addition, both transcription and protein synthesis of Blimp-1 were remarkably down-regulated (to ∼20%) by re-expression (over-expression) of EBF1. Chromatin immunoprecipitation assay revealed that EBF1 binds to proximal 5'-upstream regions around two putative EBF1 binding motifs of the gene in vivo. These results suggest that EBF1 takes part in transcriptional regulations of the Blimp-1 gene in immature B cells, and may play a key role in B cell differentiation. This is the first report on a novel EBF1 function in immature B cells as a powerful repressor of Blimp-1 gene expression. Copyright © 2012 Elsevier Inc. All rights reserved.

  8. An Unusual Phage Repressor Encoded by Mycobacteriophage BPs.

    Directory of Open Access Journals (Sweden)

    Valerie M Villanueva

    Full Text Available Temperate bacteriophages express transcription repressors that maintain lysogeny by down-regulating lytic promoters and confer superinfection immunity. Repressor regulation is critical to the outcome of infection-lysogenic or lytic growth-as well as prophage induction into lytic replication. Mycobacteriophage BPs and its relatives use an unusual integration-dependent immunity system in which the phage attachment site (attP is located within the repressor gene (33 such that site-specific integration leads to synthesis of a prophage-encoded product (gp33103 that is 33 residues shorter at its C-terminus than the virally-encoded protein (gp33136. However, the shorter form of the repressor (gp33103 is stable and active in repression of the early lytic promoter PR, whereas the longer virally-encoded form (gp33136 is inactive due to targeted degradation via a C-terminal ssrA-like tag. We show here that both forms of the repressor bind similarly to the 33-34 intergenic regulatory region, and that BPs gp33103 is a tetramer in solution. The BPs gp33103 repressor binds to five regulatory regions spanning the BPs genome, and regulates four promoters including the early lytic promoter, PR. BPs gp33103 has a complex pattern of DNA recognition in which a full operator binding site contains two half sites separated by a variable spacer, and BPs gp33103 induces a DNA bend at the full operator site but not a half site. The operator site structure is unusual in that one half site corresponds to a 12 bp palindrome identified previously, but the other half site is a highly variable variant of the palindrome.

  9. TBLR1 regulates the expression of nuclear hormone receptor co-repressors

    Directory of Open Access Journals (Sweden)

    Brown Stuart

    2006-08-01

    Full Text Available Abstract Background Transcription is regulated by a complex interaction of activators and repressors. The effectors of repression are large multimeric complexes which contain both the repressor proteins that bind to transcription factors and a number of co-repressors that actually mediate transcriptional silencing either by inhibiting the basal transcription machinery or by recruiting chromatin-modifying enzymes. Results TBLR1 [GenBank: NM024665] is a co-repressor of nuclear hormone transcription factors. A single highly conserved gene encodes a small family of protein molecules. Different isoforms are produced by differential exon utilization. Although the ORF of the predominant form contains only 1545 bp, the human gene occupies ~200 kb of genomic DNA on chromosome 3q and contains 16 exons. The genomic sequence overlaps with the putative DC42 [GenBank: NM030921] locus. The murine homologue is structurally similar and is also located on Chromosome 3. TBLR1 is closely related (79% homology at the mRNA level to TBL1X and TBL1Y, which are located on Chromosomes X and Y. The expression of TBLR1 overlaps but is distinct from that of TBL1. An alternatively spliced form of TBLR1 has been demonstrated in human material and it too has an unique pattern of expression. TBLR1 and the homologous genes interact with proteins that regulate the nuclear hormone receptor family of transcription factors. In resting cells TBLR1 is primarily cytoplasmic but after perturbation the protein translocates to the nucleus. TBLR1 co-precipitates with SMRT, a co-repressor of nuclear hormone receptors, and co-precipitates in complexes immunoprecipitated by antiserum to HDAC3. Cells engineered to over express either TBLR1 or N- and C-terminal deletion variants, have elevated levels of endogenous N-CoR. Co-transfection of TBLR1 and SMRT results in increased expression of SMRT. This co-repressor undergoes ubiquitin-mediated degradation and we suggest that the stabilization of

  10. The Promyelocytic Leukemia Zinc Finger Protein: Two Decades of Molecular Oncology

    International Nuclear Information System (INIS)

    Suliman, Bandar Ali; Xu, Dakang; Williams, Bryan Raymond George

    2012-01-01

    The promyelocytic leukemia zinc finger (PLZF) protein, also known as Zbtb16 or Zfp145, was first identified in a patient with acute promyelocytic leukemia, where a reciprocal chromosomal translocation t(11;17)(q23;q21) resulted in a fusion with the RARA gene encoding retinoic acid receptor alpha. The wild-type Zbtb16 gene encodes a transcription factor that belongs to the POK (POZ and Krüppel) family of transcriptional repressors. In addition to nine Krüppel-type sequence-specific zinc fingers, which make it a member of the Krüppel-like zinc finger protein family, the PLZF protein contains an N-terminal BTB/POZ domain and RD2 domain. PLZF has been shown to be involved in major developmental and biological processes, such as spermatogenesis, hind limb formation, hematopoiesis, and immune regulation. PLZF is localized mainly in the nucleus where it exerts its transcriptional repression function, and many post-translational modifications affect this ability and also have an impact on its cytoplasmic/nuclear dissociation. PLZF achieves its transcriptional regulation by binding to many secondary molecules to form large multi-protein complexes that bind to the regulatory elements in the promoter region of the target genes. These complexes are also capable of physically interacting with its target proteins. Recently, PLZF has become implicated in carcinogenesis as a tumor suppressor gene, since it regulates the cell cycle and apoptosis in many cell types. This review will examine the major advances in our knowledge of PLZF biological activities that augment its value as a therapeutic target, particularly in cancer and immunological diseases.

  11. The CRE1 carbon catabolite repressor of the fungus Trichoderma reesei: a master regulator of carbon assimilation

    Directory of Open Access Journals (Sweden)

    Seiboth Bernhard

    2011-05-01

    Full Text Available Abstract Background The identification and characterization of the transcriptional regulatory networks governing the physiology and adaptation of microbial cells is a key step in understanding their behaviour. One such wide-domain regulatory circuit, essential to all cells, is carbon catabolite repression (CCR: it allows the cell to prefer some carbon sources, whose assimilation is of high nutritional value, over less profitable ones. In lower multicellular fungi, the C2H2 zinc finger CreA/CRE1 protein has been shown to act as the transcriptional repressor in this process. However, the complete list of its gene targets is not known. Results Here, we deciphered the CRE1 regulatory range in the model cellulose and hemicellulose-degrading fungus Trichoderma reesei (anamorph of Hypocrea jecorina by profiling transcription in a wild-type and a delta-cre1 mutant strain on glucose at constant growth rates known to repress and de-repress CCR-affected genes. Analysis of genome-wide microarrays reveals 2.8% of transcripts whose expression was regulated in at least one of the four experimental conditions: 47.3% of which were repressed by CRE1, whereas 29.0% were actually induced by CRE1, and 17.2% only affected by the growth rate but CRE1 independent. Among CRE1 repressed transcripts, genes encoding unknown proteins and transport proteins were overrepresented. In addition, we found CRE1-repression of nitrogenous substances uptake, components of chromatin remodeling and the transcriptional mediator complex, as well as developmental processes. Conclusions Our study provides the first global insight into the molecular physiological response of a multicellular fungus to carbon catabolite regulation and identifies several not yet known targets in a growth-controlled environment.

  12. Robotic hand and fingers

    Science.gov (United States)

    Salisbury, Curt Michael; Dullea, Kevin J.

    2017-06-06

    Technologies pertaining to a robotic hand are described herein. The robotic hand includes one or more fingers releasably attached to a robotic hand frame. The fingers can abduct and adduct as well as flex and tense. The fingers are releasably attached to the frame by magnets that allow for the fingers to detach from the frame when excess force is applied to the fingers.

  13. High-throughput cell-based screening reveals a role for ZNF131 as a repressor of ERalpha signaling

    Directory of Open Access Journals (Sweden)

    Du Peige

    2008-10-01

    Full Text Available Abstract Background Estrogen receptor α (ERα is a transcription factor whose activity is affected by multiple regulatory cofactors. In an effort to identify the human genes involved in the regulation of ERα, we constructed a high-throughput, cell-based, functional screening platform by linking a response element (ERE with a reporter gene. This allowed the cellular activity of ERα, in cells cotransfected with the candidate gene, to be quantified in the presence or absence of its cognate ligand E2. Results From a library of 570 human cDNA clones, we identified zinc finger protein 131 (ZNF131 as a repressor of ERα mediated transactivation. ZNF131 is a typical member of the BTB/POZ family of transcription factors, and shows both ubiquitous expression and a high degree of sequence conservation. The luciferase reporter gene assay revealed that ZNF131 inhibits ligand-dependent transactivation by ERα in a dose-dependent manner. Electrophoretic mobility shift assay clearly demonstrated that the interaction between ZNF131 and ERα interrupts or prevents ERα binding to the estrogen response element (ERE. In addition, ZNF131 was able to suppress the expression of pS2, an ERα target gene. Conclusion We suggest that the functional screening platform we constructed can be applied for high-throughput genomic screening candidate ERα-related genes. This in turn may provide new insights into the underlying molecular mechanisms of ERα regulation in mammalian cells.

  14. Genetic analysis of Kruppel-like zinc finger 11 variants in 5864 Danish individuals: potential effect on insulin resistance and modified signal transducer and activator of transcription-3 binding by promoter variant -1659G>C

    DEFF Research Database (Denmark)

    Gutiérrez-Aguilar, Ruth; Froguel, Philippe; Hamid, Yasmin H

    2008-01-01

    CONTEXT: The transcription factor Krüppel-like zinc finger 11 (KLF11) has been suggested to contribute to genetic risk of type 2 diabetes (T2D). Our previous results showed that four KLF11 variants, in strong linkage disequilibrium (LD block including +185 A>G/Gln62Arg and -1659 G>C) were...... study to assess association to T2D and glucose metabolism-related quantitative traits. We studied effects of LD-block variants on KLF11 function and in particular, the effect of -1659G>C on transcriptional regulation of KLF11 using EMSA, chromatin immunoprecipitation, gene reporter assays, and small...... = 0.006, and P = 0.00002, respectively). In addition, binding of signal transducer and activator of transcription (STAT)-3 to the wild-type (-1659G>C) allele stimulated gene transcription, whereas STAT3 did not bind onto the mutant allele. CONCLUSIONS: We showed that KLF11 may interfere with glucose...

  15. Fingers that change color

    Science.gov (United States)

    Blanching of the fingers; Fingers - pale; Toes that change color; Toes - pale ... These conditions can cause fingers or toes to change color: Buerger disease. Chilblains. Painful inflammation of small ...

  16. The Chinese wild grapevine (Vitis pseudoreticulata) E3 ubiquitin ligase Erysiphe necator-induced RING finger protein 1 (EIRP1) activates plant defense responses by inducing proteolysis of the VpWRKY11 transcription factor.

    Science.gov (United States)

    Yu, Yihe; Xu, Weirong; Wang, Jie; Wang, Lei; Yao, Wenkong; Yang, Yazhou; Xu, Yan; Ma, Fuli; Du, Yangjian; Wang, Yuejin

    2013-11-01

    Ubiquitin-mediated regulation responds rapidly to specific stimuli; this rapidity is particularly important for defense responses to pathogen attack. Here, we investigated the role of the E3 ubiquitin ligase Erysiphe necator-induced RING finger protein 1 (EIRP1) in the defense response of Chinese wild grapevine Vitis pseudoreticulata. The regulatory function of E3 ubiquitin ligase EIRP1 was investigated using molecular, genetic and biochemical approaches. EIRP1 encodes a C3HC4-type Really Interesting New Gene (RING) finger protein that harbors E3 ligase activity. This activity requires the conserved RING domain, and VpWRKY11 also interacts with EIRP1 through the RING domain. VpWRKY11 localizes to the nucleus and activates W-box-dependent transcription in planta. EIRP1 targeted VpWRKY11 in vivo, resulting in VpWRKY11 degradation. The expression of EIRP1 and VpWRKY11 responds rapidly to powdery mildew in Vitis pseudoreticulata grapevine; also, overexpression of EIRP1 in Arabidopsis confers enhanced resistance to the pathogens Golovinomyces cichoracearum and Pseudomonas syringae pv tomato DC3000. Our data suggest that the EIRP1 E3 ligase positively regulates plant disease resistance by mediating proteolysis of the negative regulator VpWRKY11 via degradation by the 26S proteasome. © 2013 College of Horticulture. New Phytologist © 2013 New Phytologist Trust.

  17. Sonic Hedgehog-GLI Family Zinc Finger 1 Signaling Pathway Promotes the Growth and Migration of Pancreatic Cancer Cells by Regulating the Transcription of Eukaryotic Translation Initiation Factor 5A2.

    Science.gov (United States)

    Xu, Xuanfu; Liu, Hua; Zhang, Hui; Dai, Weiqi; Guo, Chuanyong; Xie, Chuangao; Wei, Shumei; He, Shengli; Xu, Xiaorong

    2015-11-01

    The Hh (hedgehog) signaling pathway is still waiting for further studies because its downstream molecular mechanism remains elusive. Because EIF5A2 (eukaryotic translation initiation factor 5A2) gene was up-regulated upon Gli1 (GLI family zinc finger 1) in pancreatic cancer (PC) cells, we speculated that this pathway might promote tumor progression through regulating EIF5A2. We investigated regulation effect of Hh signaling pathway to EIF5A2 gene transcription by Gli1 knockdown or overexpression in PC cell lines first. Then, the regulation mechanism of Gli1 to EIF5A2 gene was studied at transcription level. Finally, we studied cancer-promoting effects of Gli1-dependent EIF5A2 in PC cells. The data showed that Gli1 up-regulated expression of EIF5A2 by promoting transcription via cis-acting elements in PC cells. Moreover, vimentin gene was up-regulated significantly by sonic hedgehog (SHh)/Gli1 expression increasing, and E-cadherin was significantly reduced. The EIF5A2 knockdown partially reversed cell proliferation and migration induced by artificial SHh overexpression and inhibited epithelial mesenchymal transition process in PC cells with SHh overexpression (P cells. Thus, EIF5A2 oncogene effect could be incorporated into cancer-promoting molecular network upon Hh signaling pathway.

  18. Transcriptional regulation of the genes encoding cytochromes P450BM-1 and P450BM-3 in Bacillus megaterium by the binding of Bm3R1 repressor to Barbie box elements and operator sites.

    Science.gov (United States)

    Liang, Q; Fulco, A J

    1995-08-04

    We previously reported (Liang, Q., He, J.-S., and Fulco, A.J. (1995) J. Biol. Chem. 270, 4438-4450) that Bm3R1, a repressor regulating the expression of P450BM-3 in Bacillus megaterium, could bind to Barbie box sequences in the 5'-flanking regions of barbiturate-inducible genes. We've now shown that pentobarbital does not inhibit in vitro binding of Bm3R1 to the P450BM-3 and P450BM-1 Barbie boxes (BB3 and BB1), although the palindromic operator sequence (OIII) of P450BM-3 did have a strong competitive effect on such binding. G39E-Bm3R1, a mutant of Bm3R1, did not bind to either Barbie box. In the presence of Bm3R1, portions of the regulatory regions of P450BM-3 and P450BM-1 were protected from DNase I digestion. These included 11 of the 15 base pairs of BB3 plus 7 base pairs 3' to BB3, BB1 plus 16 base pairs 3' to BB1, and, in the 5'-flanking region of P450BM-1, segments covering most of two palindromic sequences (OII and OIII) of 24 and 52 base pairs. These DNase I-protected regions (including OIII) showed considerable sequence identity, especially in a conserved poly(A) motif. Barbiturates did not inhibit binding of Bm3R1 to OI. OII in vitro while G39E-Bm3R1 did not bind. The regulatory effects of Bm3R1 on P450BM-1 and P450BM-3 were also evaluated in vivo using heterologous chloramphenicol acetyltransferase constructs and Western blotting. In the G39E mutant strain, both P450BM-1 and P450BM-3 were constitutively expressed, and the regulatory proteins Bm1P1 and Bm3P1, although still pentobarbital-inducible, had significantly higher basal levels of synthesis. In toto, our results show that Bm3R1 represses both P450BM-1 and P450BM-3 expression and that it may effect this by coordinate binding to operator and Barbie box sequences to produce looping of the P450BM-1 and P450BM-3 regulatory regions through protein-protein interaction.

  19. Functional analysis of a novel KRAB/C2H2 zinc finger protein Mipu1

    International Nuclear Information System (INIS)

    Jiang, Lei; Tang, Daolin; Wang, Kangkai; Zhang, Huali; Yuan, Can; Duan, Dayue; Xiao, Xianzhong

    2007-01-01

    A novel rat gene, Mipu1, encodes a 608 amino acid protein with an amino-terminal KRAB domain and 14 carboxyl-terminal C 2 H 2 zinc finger motifs. Mipu1 is localized to the nucleus through its KRAB domain or the linker adjacent to its zinc finger region. Using the GST-Mipu1 bound to glutathione-Sepharose beads, a consensus putative DNA binding site (5'-TGTCTTATCGAA-3') was extracted from a random oligonucleotide library. EMSA and target detection assay showed that the probe containing the putative site can bind to purified GST-Mipu1 fusion protein. The oligonucleotide containing the putative site was inserted into the pGL3-promotor vector to produce a reporter construct. The expression of reporter gene was repressed by overexpression of Mipu1 in a dose-dependent manner. Mutation analysis of the consensus sequence indicated that the repression mediated by Mipu1 is sequence-dependent. These results suggest that Mipu1 is a nuclear protein, which functions as a transcriptional repressor

  20. A single mutation in the core domain of the lac repressor reduces leakiness

    NARCIS (Netherlands)

    Gatti-Lafranconi, Pietro; Dijkman, Willem; Devenish, Sean RA; Hollfelder, Florian

    2013-01-01

    The lac operon provides cells with the ability to switch from glucose to lactose metabolism precisely when necessary. This metabolic switch is mediated by the lac repressor (LacI), which in the absence of lactose binds to the operator DNA sequence to inhibit transcription. Allosteric rearrangements

  1. The neurotoxicant PCB-95 by increasing the neuronal transcriptional repressor REST down-regulates caspase-8 and increases Ripk1, Ripk3 and MLKL expression determining necroptotic neuronal death.

    Science.gov (United States)

    Guida, Natascia; Laudati, Giusy; Serani, Angelo; Mascolo, Luigi; Molinaro, Pasquale; Montuori, Paolo; Di Renzo, Gianfranco; Canzoniero, Lorella M T; Formisano, Luigi

    2017-10-15

    Our previous study showed that the environmental neurotoxicant non-dioxin-like polychlorinated biphenyl (PCB)-95 increases RE1-silencing transcription factor (REST) expression, which is related to necrosis, but not apoptosis, of neurons. Meanwhile, necroptosis is a type of a programmed necrosis that is positively regulated by receptor interacting protein kinase 1 (RIPK1), RIPK3 and mixed lineage kinase domain-like (MLKL) and negatively regulated by caspase-8. Here we evaluated whether necroptosis contributes to PCB-95-induced neuronal death through REST up-regulation. Our results demonstrated that in cortical neurons PCB-95 increased RIPK1, RIPK3, and MLKL expression and decreased caspase-8 at the gene and protein level. Furthermore, the RIPK1 inhibitor necrostatin-1 or siRNA-mediated RIPK1, RIPK3 and MLKL expression knockdown significantly reduced PCB-95-induced neuronal death. Intriguingly, PCB-95-induced increases in RIPK1, RIPK3, MLKL expression and decreases in caspase-8 expression were reversed by knockdown of REST expression with a REST-specific siRNA (siREST). Notably, in silico analysis of the rat genome identified a REST consensus sequence in the caspase-8 gene promoter (Casp8-RE1), but not the RIPK1, RIPK3 and MLKL promoters. Interestingly, in PCB-95-treated neurons, REST binding to the Casp8-RE1 sequence increased in parallel with a reduction in its promoter activity, whereas under the same experimental conditions, transfection of siREST or mutation of the Casp8-RE1 sequence blocked PCB-95-induced caspase-8 reduction. Since RIPK1, RIPK3 and MLKL rat genes showed no putative REST binding site, we assessed whether the transcription factor cAMP Responsive Element Binding Protein (CREB), which has a consensus sequence in all three genes, affected neuronal death. In neurons treated with PCB-95, CREB protein expression decreased in parallel with a reduction in binding to the RIPK1, RIPK3 and MLKL gene promoter sequence. Furthermore, CREB overexpression was

  2. Herpes simplex virus induces the marked up-regulation of the zinc finger transcriptional factor INSM1, which modulates the expression and localization of the immediate early protein ICP0

    Directory of Open Access Journals (Sweden)

    Kimura Hiroshi

    2011-05-01

    Full Text Available Abstract Background Herpes simplex viruses (HSVs rapidly shut off macromolecular synthesis in host cells. In contrast, global microarray analyses have shown that HSV infection markedly up-regulates a number of host cell genes that may play important roles in HSV-host cell interactions. To understand the regulatory mechanisms involved, we initiated studies focusing on the zinc finger transcription factor insulinoma-associated 1 (INSM1, a host cell protein markedly up-regulated by HSV infection. Results INSM1 gene expression in HSV-1-infected normal human epidermal keratinocytes increased at least 400-fold 9 h after infection; INSM1 promoter activity was also markedly stimulated. Expression and subcellular localization of the immediate early HSV protein ICP0 was affected by INSM1 expression, and chromatin immunoprecipitation (ChIP assays revealed binding of INSM1 to the ICP0 promoter. Moreover, the role of INSM1 in HSV-1 infection was further clarified by inhibition of HSV-1 replication by INSM1-specific siRNA. Conclusions The results suggest that INSM1 up-regulation plays a positive role in HSV-1 replication, probably by binding to the ICP0 promoter.

  3. 5'-UTR G-quadruplex structures acting as translational repressors.

    Science.gov (United States)

    Beaudoin, Jean-Denis; Perreault, Jean-Pierre

    2010-11-01

    Given that greater than 90% of the human genome is expressed, it is logical to assume that post-transcriptional regulatory mechanisms must be the primary means of controlling the flow of information from mRNA to protein. This report describes a robust approach that includes in silico, in vitro and in cellulo experiments permitting an in-depth evaluation of the impact of G-quadruplexes as translational repressors. Sequences including potential G-quadruplexes were selected within nine distinct genes encoding proteins involved in various biological processes. Their abilities to fold into G-quadruplex structures in vitro were evaluated using circular dichroism, thermal denaturation and the novel use of in-line probing. Six sequences were observed to fold into G-quadruplex structures in vitro, all of which exhibited translational inhibition in cellulo when linked to a reporter gene. Sequence analysis, direct mutagenesis and subsequent experiments were performed in order to define the rules governing the folding of G-quadruplexes. In addition, the impact of single-nucleotide polymorphism was shown to be important in the formation of G-quadruplexes located within the 5'-untranslated region of an mRNA. In light of these results, clearly the 5'-UTR G-quadruplexes represent a class of translational repressors that is broadly distributed in the cell.

  4. Identification of the minimal repression domain of SUPERMAN shows that the DLELRL hexapeptide is both necessary and sufficient for repression of transcription in Arabidopsis.

    Science.gov (United States)

    Hiratsu, Keiichiro; Mitsuda, Nobutaka; Matsui, Kyoko; Ohme-Takagi, Masaru

    2004-08-13

    We reported previously that the carboxy-terminal 30 amino acids of SUPERMAN (SUPRD) function as a repression domain in Arabidopsis. In this study, we identified the peptide sequences in SUPRD that is both necessary and sufficient for repression of transcription. To our surprise, the hexapeptide DLELRL was sufficient, by itself, to confer the ability to repress transcription on a DNA-binding domain. A database search revealed that there are 32 TFIIIA-type zinc finger proteins in the Arabidopsis genome that contain a hexapeptide sequence similar or identical to that of DLELRL. These peptides acted as repression domains, suggesting that these zinc finger proteins might function as active repressors. Further mutational analysis within DLELRL revealed that an amphiphilic motif composed of six amino acids (XLxLXL) with preferences at the first and fifth positions is necessary and sufficient for strong repression. An assay of positional effects suggested that GAL4DB-DLELRL might function as a short-range repressor. A possible mechanism of the DLELRL-mediated repression is discussed.

  5. ROG, repressor of GATA, regulates the expression of cytokine genes.

    Science.gov (United States)

    Miaw, S C; Choi, A; Yu, E; Kishikawa, H; Ho, I C

    2000-03-01

    GATA-3 is a T cell-specific transcription factor and is essential for the development of the T cell lineage. Recently, it was shown that the expression of GATA-3 is further induced in CD4+ helper T cells upon differentiation into type 2 but not type 1 effector cells. Here, we report the molecular cloning of a GATA-3 interacting protein, repressor of GATA (ROG). ROG is a lymphoid-specific gene and is rapidly induced in Th cells upon stimulation with anti-CD3. In in vitro assays, ROG represses the GATA-3-induced transactivation. Furthermore, overexpression of ROG in Th clones inhibits the production of Th cytokines. Taken together, our results suggest that ROG might play a critical role in regulating the differentiation and activation of Th cells.

  6. The transcriptional repressor HIC1 regulates intestinal immune homeostasis

    Czech Academy of Sciences Publication Activity Database

    Burrows, K.; Antignano, F.; Bramhall, M.; Chenery, A.; Scheer, S.; Kořínek, Vladimír; Underhill, T. M.; Zaph, C.

    2017-01-01

    Roč. 10, č. 6 (2017), s. 1518-1528 ISSN 1933-0219 Institutional support: RVO:68378050 Keywords : cd4(+) t-cells * anti-interleukin-17 monoclonal-antibody * cd103(+) dendritic cells * acid receptor-alpha * retinoic acid * t(h)17 cells * target genes * double-blind * tgf-beta * differentiation Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Biochemistry and molecular biology Impact factor: 7.478, year: 2016

  7. Construction of a multicontrol sterility system for a maize male-sterile line and hybrid seed production based on the ZmMs7 gene encoding a PHD-finger transcription factor.

    Science.gov (United States)

    Zhang, Danfeng; Wu, Suowei; An, Xueli; Xie, Ke; Dong, Zhenying; Zhou, Yan; Xu, Liwen; Fang, Wen; Liu, Shensi; Liu, Shuangshuang; Zhu, Taotao; Li, Jinping; Rao, Liqun; Zhao, Jiuran; Wan, Xiangyuan

    2018-02-01

    Although hundreds of genetic male sterility (GMS) mutants have been identified in maize, few are commercially used due to a lack of effective methods to produce large quantities of pure male-sterile seeds. Here, we develop a multicontrol sterility (MCS) system based on the maize male sterility 7 (ms7) mutant and its wild-type Zea mays Male sterility 7 (ZmMs7) gene via a transgenic strategy, leading to the utilization of GMS in hybrid seed production. ZmMs7 is isolated by a map-based cloning approach and encodes a PHD-finger transcription factor orthologous to rice PTC1 and Arabidopsis MS1. The MCS transgenic maintainer lines are developed based on the ms7-6007 mutant transformed with MCS constructs containing the (i) ZmMs7 gene to restore fertility, (ii) α-amylase gene ZmAA and/or (iii) DNA adenine methylase gene Dam to devitalize transgenic pollen, (iv) red fluorescence protein gene DsRed2 or mCherry to mark transgenic seeds and (v) herbicide-resistant gene Bar for transgenic seed selection. Self-pollination of the MCS transgenic maintainer line produces transgenic red fluorescent seeds and nontransgenic normal colour seeds at a 1:1 ratio. Among them, all the fluorescent seeds are male fertile, but the seeds with a normal colour are male sterile. Cross-pollination of the transgenic plants to male-sterile plants propagates male-sterile seeds with high purity. Moreover, the transgene transmission rate through pollen of transgenic plants harbouring two pollen-disrupted genes is lower than that containing one pollen-disrupted gene. The MCS system has great potential to enhance the efficiency of maize male-sterile line propagation and commercial hybrid seed production. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  8. Trigger Finger (Stenosing Tenosynovitis)

    Science.gov (United States)

    ... a friend * required fields From * To * DESCRIPTION Stenosing tenosynovitis is a condition commonly known as “trigger finger.” It is sometimes also called “trigger thumb.” The tendons that bend the fingers glide easily with ...

  9. Potential role for Id myogenic repressors in apoptosis and attenuation of hypertrophy in muscles of aged rats.

    NARCIS (Netherlands)

    Alway, S.E.; Degens, H.; Krishnamurthy, G.; Smith, C.A.

    2002-01-01

    Aging attenuates the overload-induced increase in myogenic regulatory transcription factor (MRF) expression and the extent of muscle enlargement. To identify whether mRNA levels of repressors of the MRFs are greater in overloaded muscles from aged animals, overload was achieved in plantaris muscle

  10. Mechanism of Metal Ion Activation of the Diphtheria Toxin Repressor DtxR

    Energy Technology Data Exchange (ETDEWEB)

    D' Aquino,J.; Tetenbaum-Novatt, J.; White, A.; Berkovitch, F.; Ringe, D.

    2005-01-01

    The diphtheria toxin repressor (DtxR) is a metal ion-activated transcriptional regulator that has been linked to the virulence of Corynebacterium diphtheriae. Structure determination has shown that there are two metal ion binding sites per repressor monomer, and site-directed mutagenesis has demonstrated that binding site 2 (primary) is essential for recognition of the target DNA repressor, leaving the role of binding site 1 (ancillary) unclear. Calorimetric techniques have demonstrated that although binding site 1 (ancillary) has high affinity for metal ion with a binding constant of 2 x 10{sup -7}, binding site 2 (primary) is a low-affinity binding site with a binding constant of 6.3 x 10{sup -4}. These two binding sites act in an independent fashion, and their contribution can be easily dissected by traditional mutational analysis. Our results clearly demonstrate that binding site 1 (ancillary) is the first one to be occupied during metal ion activation, playing a critical role in stabilization of the repressor. In addition, structural data obtained for the mutants Ni-DtxR(H79A, C102D), reported here, and the previously reported DtxR(H79A) have allowed us to propose a mechanism of metal activation for DtxR.

  11. C. elegans ZAG-1, a Zn-finger-homeodomain protein, regulates axonal development and neuronal differentiation.

    Science.gov (United States)

    Clark, Scott G; Chiu, Catherine

    2003-08-01

    Neurons acquire distinct cell identities and implement differential gene programs to generate their appropriate neuronal attributes. On the basis of position, axonal structure and synaptic connectivity, the 302 neurons of the nematode Ceanorhabditis elegans are divided into 118 classes. The development and differentiation of many neurons require the gene zag-1, which encodes a deltaEF1/ZFH-1 Zn-finger-homeodomain protein. zag-1 mutations cause misexpression of neuron-specific genes, block formation of stereotypic axon branches, perturb neuronal migrations, and induce various axon-guidance, fasciculation and branching errors. A zag-1-GFP translational reporter is expressed transiently in most or all neurons during embryogenesis and in select neurons during the first larval stage. Analysis of the zag-1 promoter reveals that zag-1 is expressed in neurons and specific muscles, and that ZAG-1 directly represses its own expression. zag-1 activity also downregulates expression of genes involved in either the synthesis or reuptake of serotonin, dopamine and GABA. We propose that ZAG-1 acts as a transcriptional repressor to regulate multiple, discrete, neuron-specific aspects of terminal differentiation, including cell migration, axonal development and gene expression.

  12. Multiple Fingers - One Gestalt.

    Science.gov (United States)

    Lezkan, Alexandra; Manuel, Steven G; Colgate, J Edward; Klatzky, Roberta L; Peshkin, Michael A; Drewing, Knut

    2016-01-01

    The Gestalt theory of perception offered principles by which distributed visual sensations are combined into a structured experience ("Gestalt"). We demonstrate conditions whereby haptic sensations at two fingertips are integrated in the perception of a single object. When virtual bumps were presented simultaneously to the right hand's thumb and index finger during lateral arm movements, participants reported perceiving a single bump. A discrimination task measured the bump's perceived location and perceptual reliability (assessed by differential thresholds) for four finger configurations, which varied in their adherence to the Gestalt principles of proximity (small versus large finger separation) and synchrony (virtual spring to link movements of the two fingers versus no spring). According to models of integration, reliability should increase with the degree to which multi-finger cues integrate into a unified percept. Differential thresholds were smaller in the virtual-spring condition (synchrony) than when fingers were unlinked. Additionally, in the condition with reduced synchrony, greater proximity led to lower differential thresholds. Thus, with greater adherence to Gestalt principles, thresholds approached values predicted for optimal integration. We conclude that the Gestalt principles of synchrony and proximity apply to haptic perception of surface properties and that these principles can interact to promote multi-finger integration.

  13. SENSITIVE TO PROTON RHIZOTOXICITY1, CALMODULIN BINDING TRANSCRIPTION ACTIVATOR2, and other transcription factors are involved in ALUMINUM-ACTIVATED MALATE TRANSPORTER1 expression.

    Science.gov (United States)

    Tokizawa, Mutsutomo; Kobayashi, Yuriko; Saito, Tatsunori; Kobayashi, Masatomo; Iuchi, Satoshi; Nomoto, Mika; Tada, Yasuomi; Yamamoto, Yoshiharu Y; Koyama, Hiroyuki

    2015-03-01

    In Arabidopsis (Arabidopsis thaliana) the root apex is protected from aluminum (Al) rhizotoxicity by excretion of malate, an Al chelator, by ALUMINUM-ACTIVATED MALATE TRANSPORTER1 (AtALMT1). AtALMT1 expression is fundamentally regulated by the SENSITIVE TO PROTON RHIZOTOXICITY1 (STOP1) zinc finger protein, but other transcription factors have roles that enable Al-inducible expression with a broad dynamic range. In this study, we characterized multiple cis-elements in the AtALMT1 promoter that interact with transcription factors. In planta complementation assays of AtALMT1 driven by 5' truncated promoters of different lengths showed that the promoter region between -540 and 0 (the first ATG) restored the Al-sensitive phenotype of atalm1 and thus contains cis-elements essential for AtALMT1 expression for Al tolerance. Computation of overrepresented octamers showed that eight regions in this promoter region contained potential cis-elements involved in Al induction and STOP1 regulation. Mutation in a position around -297 from the first ATG completely inactivated AtALMT1 expression and Al response. In vitro binding assays showed that this region contained the STOP1 binding site, which accounted for the recognition by four zinc finger domains of the protein. Other positions were characterized as cis-elements that regulated expression by repressors and activators and a transcription factor that determines root tip expression of AtALMT1. From the consensus of known cis-elements, we identified CALMODULIN-BINDING TRANSCRIPTION ACTIVATOR2 to be an activator of AtALMT1 expression. Al-inducible expression of AtALMT1 changed transcription starting sites, which increased the abundance of transcripts with a shortened 5' untranslated region. The present analyses identified multiple mechanisms that regulate AtALMT1 expression. © 2015 American Society of Plant Biologists. All Rights Reserved.

  14. Fur is a repressor of biofilm formation in Yersinia pestis.

    Directory of Open Access Journals (Sweden)

    Fengjun Sun

    Full Text Available BACKGROUND: Yersinia pestis synthesizes the attached biofilms in the flea proventriculus, which is important for the transmission of this pathogen by fleas. The hmsHFRS operons is responsible for the synthesis of exopolysaccharide (the major component of biofilm matrix, which is activated by the signaling molecule 3', 5'-cyclic diguanylic acid (c-di-GMP synthesized by the only two diguanylate cyclases HmsT, and YPO0449 (located in a putative operonYPO0450-0448. METHODOLOGY/PRINCIPAL FINDINGS: The phenotypic assays indicated that the transcriptional regulator Fur inhibited the Y. pestis biofilm production in vitro and on nematode. Two distinct Fur box-like sequences were predicted within the promoter-proximal region of hmsT, suggesting that hmsT might be a direct Fur target. The subsequent primer extension, LacZ fusion, electrophoretic mobility shift, and DNase I footprinting assays disclosed that Fur specifically bound to the hmsT promoter-proximal region for repressing the hmsT transcription. In contrast, Fur had no regulatory effect on hmsHFRS and YPO0450-0448 at the transcriptional level. The detection of intracellular c-di-GMP levels revealed that Fur inhibited the c-di-GMP production. CONCLUSIONS/SIGNIFICANCE: Y. pestis Fur inhibits the c-di-GMP production through directly repressing the transcription of hmsT, and thus it acts as a repressor of biofilm formation. Since the relevant genetic contents for fur, hmsT, hmsHFRS, and YPO0450-0448 are extremely conserved between Y. pestis and typical Y. pseudotuberculosis, the above regulatory mechanisms can be applied to Y. pseudotuberculosis.

  15. Tendon Driven Finger Actuation System

    Science.gov (United States)

    Ihrke, Chris A. (Inventor); Reich, David M. (Inventor); Bridgwater, Lyndon (Inventor); Linn, Douglas Martin (Inventor); Askew, Scott R. (Inventor); Diftler, Myron A. (Inventor); Platt, Robert (Inventor); Hargrave, Brian (Inventor); Valvo, Michael C. (Inventor); Abdallah, Muhammad E. (Inventor); hide

    2013-01-01

    A humanoid robot includes a robotic hand having at least one finger. An actuation system for the robotic finger includes an actuator assembly which is supported by the robot and is spaced apart from the finger. A tendon extends from the actuator assembly to the at least one finger and ends in a tendon terminator. The actuator assembly is operable to actuate the tendon to move the tendon terminator and, thus, the finger.

  16. GLI3 repressor controls nephron number via regulation of Wnt11 and Ret in ureteric tip cells.

    Directory of Open Access Journals (Sweden)

    Jason E Cain

    Full Text Available Truncating GLI3 mutations in Pallister-Hall Syndrome with renal malformation suggests a requirement for Hedgehog signaling during renal development. HH-dependent signaling increases levels of GLI transcriptional activators and decreases processing of GLI3 to a shorter transcriptional repressor. Previously, we showed that Shh-deficiency interrupts early inductive events during renal development in a manner dependent on GLI3 repressor. Here we identify a novel function for GLI3 repressor in controlling nephron number. During renal morphogenesis, HH signaling activity, assayed by expression of Ptc1-lacZ, is localized to ureteric cells of the medulla, but is undetectable in the cortex. Targeted inactivation of Smo, the HH effector, in the ureteric cell lineage causes no detectable abnormality in renal morphogenesis. The functional significance of absent HH signaling activity in cortical ureteric cells was determined by targeted deletion of Ptc1, the SMO inhibitor, in the ureteric cell lineage. Ptc1(-/-UB mice demonstrate ectopic Ptc1-lacZ expression in ureteric branch tips and renal hypoplasia characterized by reduced kidney size and a paucity of mature and intermediate nephrogenic structures. Ureteric tip cells are remarkable for abnormal morphology and impaired expression of Ret and Wnt11, markers of tip cell differentiation. A finding of renal hypoplasia in Gli3(-/- mice suggests a pathogenic role for reduced GLI3 repressor in the Ptc1(-/-UB mice. Indeed, constitutive expression of GLI3 repressor via the Gli3(Delta699 allele in Ptc1(-/-UB mice restores the normal pattern of HH signaling, and expression of Ret and Wnt11 and rescued the renal phenotype. Thus, GLI3 repressor controls nephron number by regulating ureteric tip cell expression of Wnt11 and Ret.

  17. The lactose repressor system: paradigms for regulation, allosteric behavior and protein folding.

    Science.gov (United States)

    Wilson, C J; Zhan, H; Swint-Kruse, L; Matthews, K S

    2007-01-01

    In 1961, Jacob and Monod proposed the operon model for gene regulation based on metabolism of lactose in Escherichia coli. This proposal was followed by an explication of allosteric behavior by Monod and colleagues. The operon model rationally depicted how genetic mechanisms can control metabolic events in response to environmental stimuli via coordinated transcription of a set of genes with related function (e.g. metabolism of lactose). The allosteric response found in the lactose repressor and many other proteins has been extended to a variety of cellular signaling pathways in all organisms. These two models have shaped our view of modern molecular biology and captivated the attention of a surprisingly broad range of scientists. More recently, the lactose repressor monomer was used as a model system for experimental and theoretical explorations of protein folding mechanisms. Thus, the lac system continues to advance our molecular understanding of genetic control and the relationship between sequence, structure and function.

  18. Suppression of the biosynthesis of proanthocyanidin in Arabidopsis by a chimeric PAP1 repressor.

    Science.gov (United States)

    Matsui, Kyoko; Tanaka, Hideo; Ohme-Takagi, Masaru

    2004-11-01

    Flavonoids are secondary metabolites that are specific to higher plants. PAP1, a member of the family of MYB domain transcription factors in Arabidopsis, is a positive regulator of the biosynthesis of anthocyanin. We show here that a chimeric PAP1 repressor, in which the EAR-motif repression domain from SUPERMAN was fused to PAP1, suppressed the expression of four flavonoid biosynthetic genes, namely CHS, DFR, LDOX, and BAN, in siliques, and inhibited the accumulation of proanthocyanidin, even in the presence of an endogenous positive regulator, such as TT2. This suppression resulted in the formation of light yellow seeds in 35S::PAP1SRDX transgenic plants. Our results indicate that PAP1 has the potential ability to regulate the biosynthesis not only of anthocyanin but also of proanthocyanidin. Our gene silencing system, using chimeric repressors, appears to be a useful tool for the manipulation of the biosynthesis of secondary metabolites in plants.

  19. Nac1 interacts with the POZ-domain transcription factor, Miz1

    Science.gov (United States)

    Stead, Mark A.; Wright, Stephanie C.

    2014-01-01

    Nac1 (nucleus accumbens 1) is a POZ (poxvirus and zinc finger)-domain transcriptional repressor that is expressed at high levels in ovarian serous carcinoma. Here we identify Nac1 as a novel interacting partner of the POZ-domain transcriptional activator, Miz1 (Myc-interacting zinc-finger protein 1), and using chemical crosslinking we show that this association is mediated by a heterodimeric interaction of the Nac1 and Miz1 POZ domains. Nac1 is found in discrete bodies within the nucleus of mammalian cells, and we demonstrate the relocalization of Miz1 to these structures in transfected HeLa cells. We show that siRNA (small interfering RNA)-mediated knockdown of Nac1 in ovarian cancer cells results in increased levels of the Miz1 target gene product, p21Cip1. The interaction of Nac1 with Miz1 may thus be relevant to its mechanism of tumourigenesis in ovarian cancer. PMID:24702277

  20. Alteration of light-dependent gene regulation by the absence of the RCO-1/RCM-1 repressor complex in the fungus Neurospora crassa.

    Directory of Open Access Journals (Sweden)

    Carmen Ruger-Herreros

    Full Text Available The activation of transcription by light in the fungus Neurospora crassa requires the White Collar Complex (WCC, a photoreceptor and transcription factor complex. After light reception two WCCs interact and bind the promoters of light-regulated genes to activate transcription. This process is regulated by VVD, a small photoreceptor that disrupts the interaction between WCCs and leads to a reduction in transcription after long exposures to light. The N. crassa RCO-1/RCM-1 repressor complex is the homolog of the Tup1-Ssn6 repressor complex in yeast, and its absence modifies photoadaptation. We show that the absence of the RCO-1/RCM-1 repressor complex leads to several alterations in transcription that are gene-specific: an increase in the accumulation of mRNAs in the dark, a repression of transcription, and a derepression of transcription after long exposures to light. The absence of the RCO-1/RCM-1 repressor complex leads to lower VVD levels that are available for the regulation of the activity of the WCC. The reduction in the amount of VVD results in increased WCC binding to the promoters of light-regulated genes in the dark and after long exposures to light, leading to the modification of photoadaptation that has been observed in rco-1 and rcm-1 mutants. Our results show that the photoadaptation phenotype of mutants in the RCO-1/RCM-1 repressor complex is, at least in part, an indirect consequence of the reduction of vvd transcription, and the resulting modification in the regulation of transcription by the WCC.

  1. Dominant repression of target genes by chimeric repressors that include the EAR motif, a repression domain, in Arabidopsis.

    Science.gov (United States)

    Hiratsu, Keiichiro; Matsui, Kyoko; Koyama, Tomotsugu; Ohme-Takagi, Masaru

    2003-06-01

    The redundancy of genes for plant transcription factors often interferes with efforts to identify the biologic functions of such factors. We show here that four different transcription factors fused to the EAR motif, a repression domain of only 12 amino acids, act as dominant repressors in transgenic Arabidopsis and suppress the expression of specific target genes, even in the presence of the redundant transcription factors, with resultant dominant loss-of-function phenotypes. Chimeric EIN3, CUC1, PAP1, and AtMYB23 repressors that included the EAR motif dominantly suppressed the expression of their target genes and caused insensitivity to ethylene, cup-shaped cotyledons, reduction in the accumulation of anthocyanin, and absence of trichomes, respectively. This chimeric repressor silencing technology (CRES-T), exploiting the EAR-motif repression domain, is simple and effective and can overcome genetic redundancy. Thus, it should be useful not only for the rapid analysis of the functions of redundant plant transcription factors but also for the manipulation of plant traits via the suppression of gene expression that is regulated by specific transcription factors.

  2. Mixing methods, tasting fingers

    DEFF Research Database (Denmark)

    Mann, Anna; Mol, Annemarie; Satalkar, Priya

    2011-01-01

    This article reports on an ethnographic experiment. Four finger eating experts and three novices sat down for a hot meal and ate with their hands. Drawing on the technique of playing with the familiar and the strange, our aim was not to explain our responses, but to articulate them. As we seek...... words to do so, we are compelled to stretch the verb "to taste." Tasting, or so our ethnographic experiment suggests, need not be understood as an activity confined to the tongue. Instead, if given a chance, it may viscously spread out to the fingers and come to include appreciative reactions otherwise...

  3. Multi-fingered robotic hand

    Science.gov (United States)

    Ruoff, Carl F. (Inventor); Salisbury, Kenneth, Jr. (Inventor)

    1990-01-01

    A robotic hand is presented having a plurality of fingers, each having a plurality of joints pivotally connected one to the other. Actuators are connected at one end to an actuating and control mechanism mounted remotely from the hand and at the other end to the joints of the fingers for manipulating the fingers and passing externally of the robot manipulating arm in between the hand and the actuating and control mechanism. The fingers include pulleys to route the actuators within the fingers. Cable tension sensing structure mounted on a portion of the hand are disclosed, as is covering of the tip of each finger with a resilient and pliable friction enhancing surface.

  4. A Finger Exoskeleton Robot for Finger Movement Rehabilitation

    Directory of Open Access Journals (Sweden)

    Tzu-Heng Hsu

    2017-07-01

    Full Text Available In this study, a finger exoskeleton robot has been designed and presented. The prototype device was designed to be worn on the dorsal side of the hand to assist in the movement and rehabilitation of the fingers. The finger exoskeleton is 3D-printed to be low-cost and has a transmission mechanism consisting of rigid serial links which is actuated by a stepper motor. The actuation of the robotic finger is by a sliding motion and mimics the movement of the human finger. To make it possible for the patient to use the rehabilitation device anywhere and anytime, an Arduino™ control board and a speech recognition board were used to allow voice control. As the robotic finger follows the patients voice commands the actual motion is analyzed by Tracker image analysis software. The finger exoskeleton is designed to flex and extend the fingers, and has a rotation range of motion (ROM of 44.2°.

  5. Design of thermolabile bacteriophage repressor mutants by comparative molecular modeling

    NARCIS (Netherlands)

    Nauta, A; vandenBurg, B; Karsens, H; Venema, G; Kok, J; Burg, Bertus van den

    1997-01-01

    Comparative molecular modeling was performed with repressor protein Rro of the temperate Lactococcus lactis bacteriophage r1t using the known 3D-structures of related repressors in order to obtain thermolabile derivatives of Rro. Rro residues presumed to stabilize a nonhomologous but structurally

  6. Mixing methods, tasting fingers

    DEFF Research Database (Denmark)

    Mann, Anna; Mol, Annemarie; Satalkar, Priya

    2011-01-01

    This article reports on an ethnographic experiment. Four finger eating experts and three novices sat down for a hot meal and ate with their hands. Drawing on the technique of playing with the familiar and the strange, our aim was not to explain our responses, but to articulate them. As we seek wo...

  7. The EH1 motif in metazoan transcription factors

    Directory of Open Access Journals (Sweden)

    Copley Richard R

    2005-11-01

    Full Text Available Abstract Background The Engrailed Homology 1 (EH1 motif is a small region, believed to have evolved convergently in homeobox and forkhead containing proteins, that interacts with the Drosophila protein groucho (C. elegans unc-37, Human Transducin-like Enhancers of Split. The small size of the motif makes its reliable identification by computational means difficult. I have systematically searched the predicted proteomes of Drosophila, C. elegans and human for further instances of the motif. Results Using motif identification methods and database searching techniques, I delimit which homeobox and forkhead domain containing proteins also have likely EH1 motifs. I show that despite low database search scores, there is a significant association of the motif with transcription factor function. I further show that likely EH1 motifs are found in combination with T-Box, Zinc Finger and Doublesex domains as well as discussing other plausible candidate associations. I identify strong candidate EH1 motifs in basal metazoan phyla. Conclusion Candidate EH1 motifs exist in combination with a variety of transcription factor domains, suggesting that these proteins have repressor functions. The distribution of the EH1 motif is suggestive of convergent evolution, although in many cases, the motif has been conserved throughout bilaterian orthologs. Groucho mediated repression was established prior to the evolution of bilateria.

  8. Novel INHAT repressor (NIR) is required for early lymphocyte development.

    Science.gov (United States)

    Ma, Chi A; Pusso, Antonia; Wu, Liming; Zhao, Yongge; Hoffmann, Victoria; Notarangelo, Luigi D; Fowlkes, B J; Jain, Ashish

    2014-09-23

    Novel inhibitor of histone acetyltransferase repressor (NIR) is a transcriptional corepressor with inhibitor of histone acetyltransferase activity and is a potent suppressor of p53. Although NIR deficiency in mice leads to early embryonic lethality, lymphoid-restricted deletion resulted in the absence of double-positive CD4(+)CD8(+) thymocytes, whereas bone-marrow-derived B cells were arrested at the B220(+)CD19(-) pro-B-cell stage. V(D)J recombination was preserved in NIR-deficient DN3 double-negative thymocytes, suggesting that NIR does not affect p53 function in response to physiologic DNA breaks. Nevertheless, the combined deficiency of NIR and p53 provided rescue of DN3L double-negative thymocytes and their further differentiation to double- and single-positive thymocytes, whereas B cells in the marrow further developed to the B220(+)CD19(+) pro-B-cell stage. Our results show that NIR cooperate with p53 to impose checkpoint for the generation of mature B and T lymphocytes.

  9. DWARF 53 acts as a repressor of strigolactone signalling in rice

    Science.gov (United States)

    Jiang, Liang; Liu, Xue; Xiong, Guosheng; Liu, Huihui; Chen, Fulu; Wang, Lei; Meng, Xiangbing; Liu, Guifu; Yu, Hong; Yuan, Yundong; Yi, Wei; Zhao, Lihua; Ma, Honglei; He, Yuanzheng; Wu, Zhongshan; Melcher, Karsten; Qian, Qian; Xu, H. Eric; Wang, Yonghong; Li, Jiayang

    2013-12-01

    Strigolactones (SLs) are a group of newly identified plant hormones that control plant shoot branching. SL signalling requires the hormone-dependent interaction of DWARF 14 (D14), a probable candidate SL receptor, with DWARF 3 (D3), an F-box component of the Skp-Cullin-F-box (SCF) E3 ubiquitin ligase complex. Here we report the characterization of a dominant SL-insensitive rice (Oryza sativa) mutant dwarf 53 (d53) and the cloning of D53, which encodes a substrate of the SCFD3 ubiquitination complex and functions as a repressor of SL signalling. Treatments with GR24, a synthetic SL analogue, cause D53 degradation via the proteasome in a manner that requires D14 and the SCFD3 ubiquitin ligase, whereas the dominant form of D53 is resistant to SL-mediated degradation. Moreover, D53 can interact with transcriptional co-repressors known as TOPLESS-RELATED PROTEINS. Our results suggest a model of SL signalling that involves SL-dependent degradation of the D53 repressor mediated by the D14-D3 complex.

  10. H-NS is a repressor of major virulence gene loci in Vibrio parahaemolyticus

    Directory of Open Access Journals (Sweden)

    Dongsheng eZhou

    2014-12-01

    Full Text Available Vibrio parahaemolyticus, a leading cause of seafood-associated diarrhea and gastroenteritis, harbors three major virulence gene loci T3SS1, Vp-PAI (T3SS1+tdh2 and T6SS2. As showing is this study, the nucleoid-associated DNA-binding regulator H-NS binds to multiple promoter-proximal regions in each of the above three loci to repress their transcription, and moreover H-NS inhibits the cytotoxicitiy, enterotoxicity, hemolytic activity, and mouse lethality of V. parahaemolyticus. H-NS appears to act as a major repressor of the virulence of this pathogen.

  11. Vascular plant one-zinc-finger protein 2 is localized both to the nucleus and stress granules under heat stress in Arabidopsis.

    Science.gov (United States)

    Koguchi, Misaki; Yamasaki, Kanako; Hirano, Tomoko; Sato, Masa H

    2017-03-04

    VASCULAR PLANT ONE-ZINC FINGER (VOZ)1/and VOZ2 have an ability to bind to the specific cis-element in the AVP1 promoter of Arabidopsis, which function on the PhyB-dependent flowering and possibly in various stress responses as potential transcription factors, although nuclear localization of VOZ proteins is still unclear. In this study, we found that VOZ2 is dispersed throughout the cytoplasm under normal growth conditions, whereas VOZ2 is transferred not only to the nucleus but also to the cytoplasmic foci under heat stress conditions. The VOZ2 foci predominantly co-localized with a marker of stress granules (SGs), which were cytoplasmic granular structures for mRNA storage and decay under abiotic stress conditions. We also demonstrated that GFP-VOZ2 with a nuclear localization signal was rapidly degraded via the ubiquitin/proteasome pathway under the heat stress conditions. Also, stress-related expression of DREB2A in the voz1voz2 mutant was significantly upregulated by heat stress as compared with that in the wild-type Arabidopsis. Our results suggest that VOZ2 is localized to SGs and nucleus under heat stress conditions, and functions as a transcriptional repressor of DREB2A in Arabidopsis.

  12. The regulation of transcriptional repression in hypoxia.

    Science.gov (United States)

    Cavadas, Miguel A S; Cheong, Alex; Taylor, Cormac T

    2017-07-15

    A sufficient supply molecular oxygen is essential for the maintenance of physiologic metabolism and bioenergetic homeostasis for most metazoans. For this reason, mechanisms have evolved for eukaryotic cells to adapt to conditions where oxygen demand exceeds supply (hypoxia). These mechanisms rely on the modification of pre-existing proteins, translational arrest and transcriptional changes. The hypoxia inducible factor (HIF; a master regulator of gene induction in response to hypoxia) is responsible for the majority of induced gene expression in hypoxia. However, much less is known about the mechanism(s) responsible for gene repression, an essential part of the adaptive transcriptional response. Hypoxia-induced gene repression leads to a reduction in energy demanding processes and the redirection of limited energetic resources to essential housekeeping functions. Recent developments have underscored the importance of transcriptional repressors in cellular adaptation to hypoxia. To date, at least ten distinct transcriptional repressors have been reported to demonstrate sensitivity to hypoxia. Central among these is the Repressor Element-1 Silencing Transcription factor (REST), which regulates over 200 genes. In this review, written to honor the memory and outstanding scientific legacy of Lorenz Poellinger, we provide an overview of our existing knowledge with respect to transcriptional repressors and their target genes in hypoxia. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Identification of operator sites of the CI repressor of phage TP901-1: evolutionary link to other phages

    International Nuclear Information System (INIS)

    Johansen, Annette H.; Broendsted, Lone; Hammer, Karin

    2003-01-01

    The repressor encoded by the cI gene of the temperate Lactococcus lactis subsp. cremoris bacteriophage TP901-1 has been purified. Gel-retardation and footprinting analyses identified three palindromic operator sites (O R , O L , and O D ). The operator site O R is located between the two divergent early promoters P R and P L , O L overlaps the transcriptional start of the lytic P L promoter, and O D is located downstream of the mor gene, the first gene in the lytic gene cluster. The function of O L was verified by mutational analysis. Binding was found to be specific and cooperative. Multimeric forms of the repressor were observed, thus indicating that the repressor may bind simultaneously to all three operator sites. Inverted repeats with homology to the operator sites of TP901-1 were identified in phage genomes encoding repressors homologous to CI of TP901-1. Interestingly, the locations of these repeats on the phage genomes correspond to those found in TP901-1, indicating that the same system of cooperative repression of early phage promoters has been inherited by modular evolution

  14. ABA Suppresses Root Hair Growth via the OBP4 Transcriptional Regulator1[OPEN

    Science.gov (United States)

    Kawamura, Ayako; Schäfer, Sabine; Breuer, Christian; Shibata, Michitaro; Mitsuda, Nobutaka; Ohme-Takagi, Masaru; Matsui, Minami

    2017-01-01

    Plants modify organ growth and tune morphogenesis in response to various endogenous and environmental cues. At the cellular level, organ growth is often adjusted by alterations in cell growth, but the molecular mechanisms underlying this control remain poorly understood. In this study, we identify the DNA BINDING WITH ONE FINGER (DOF)-type transcription regulator OBF BINDING PROTEIN4 (OBP4) as a repressor of cell growth. Ectopic expression of OBP4 in Arabidopsis (Arabidopsis thaliana) inhibits cell growth, resulting in severe dwarfism and the repression of genes involved in the regulation of water transport, root hair development, and stress responses. Among the basic helix-loop-helix transcription factors known to control root hair growth, OBP4 binds the ROOT HAIR DEFECTIVE6-LIKE2 (RSL2) promoter to repress its expression. The accumulation of OBP4 proteins is detected in expanding root epidermal cells, and its expression level is increased by the application of abscisic acid (ABA) at concentrations sufficient to inhibit root hair growth. ABA-dependent induction of OBP4 is associated with the reduced expression of RSL2. Furthermore, ectopic expression of OBP4 or loss of RSL2 function results in ABA-insensitive root hair growth. Taken together, our results suggest that OBP4-mediated transcriptional repression of RSL2 contributes to the ABA-dependent inhibition of root hair growth in Arabidopsis. PMID:28167701

  15. Snail recruits Ring1B to mediate transcriptional repression and cell migration in pancreatic cancer cells.

    Science.gov (United States)

    Chen, Jiangzhi; Xu, Hong; Zou, Xiuqun; Wang, Jiamin; Zhu, Yi; Chen, Hao; Shen, Baiyong; Deng, Xiaxing; Zhou, Aiwu; Chin, Y Eugene; Rauscher, Frank J; Peng, Chenghong; Hou, Zhaoyuan

    2014-08-15

    Transcriptional repressor Snail is a master regulator of epithelial-mesenchymal transition (EMT), yet the epigenetic mechanism governing Snail to induce EMT is not well understood. Here, we report that in pancreatic ductal adenocarcinoma (PDAC), elevated levels of the ubiquitin E3 ligase Ring1B and Snail, along with elevated monoubiquitination of H2A at K119 (H2AK119Ub1), are highly correlated with poor survival. Mechanistic investigations identified Ring1B as a Snail-interacting protein and showed that the carboxyl zinc fingers of Snail recruit Ring1B and its paralog Ring1A to repress its target promoters. Simultaneous depletion of Ring1A and Ring1B in pancreatic cancer cells decreased Snail binding to the target chromatin, abolished H2AK119Ub1 modification, and thereby compromised Snail-mediated transcriptional repression and cell migration. We found that Ring1B and the SNAG-associated chromatin modifier EZH2 formed distinct protein complexes with Snail and that EZH2 was required for Snail-Ring1A/B recruitment to the target promoter. Collectively, our results unravel an epigenetic mechanism underlying transcriptional repression by Snail, suggest Ring1A/B as a candidate therapeutic target, and identify H2AK119Ub1 as a potential biomarker for PDAC diagnosis and prognosis. ©2014 American Association for Cancer Research.

  16. Robotic Finger Assembly

    Science.gov (United States)

    Ihrke, Chris A. (Inventor); Bridgwater, Lyndon (Inventor); Diftler, Myron A. (Inventor); Linn, Douglas Martin (Inventor); Platt, Robert J., Jr. (Inventor); Hargrave, Brian (Inventor); Askew, Scott R. (Inventor); Valvo, Michael C. (Inventor)

    2014-01-01

    A robotic hand includes a finger with first, second, and third phalanges. A first joint rotatably connects the first phalange to a base structure. A second joint rotatably connects the first phalange to the second phalange. A third joint rotatably connects the third phalange to the second phalange. The second joint and the third joint are kinematically linked such that the position of the third phalange with respect to the second phalange is determined by the position of the second phalange with respect to the first phalange.

  17. Crystal Structure of the CLOCK Transactivation Domain Exon19 in Complex with a Repressor

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Zhiqiang; Su, Lijing; Pei, Jimin; Grishin, Nick V.; Zhang, Hong (UTSMC)

    2017-08-01

    In the canonical clock model, CLOCK:BMAL1-mediated transcriptional activation is feedback regulated by its repressors CRY and PER and, in association with other coregulators, ultimately generates oscillatory gene expression patterns. How CLOCK:BMAL1 interacts with coregulator(s) is not well understood. Here we report the crystal structures of the mouse CLOCK transactivating domain Exon19 in complex with CIPC, a potent circadian repressor that functions independently of CRY and PER. The Exon19:CIPC complex adopts a three-helical coiled-coil bundle conformation containing two Exon19 helices and one CIPC. Unique to Exon19:CIPC, three highly conserved polar residues, Asn341 of CIPC and Gln544 of the two Exon19 helices, are located at the mid-section of the coiled-coil bundle interior and form hydrogen bonds with each other. Combining results from protein database search, sequence analysis, and mutagenesis studies, we discovered for the first time that CLOCK Exon19:CIPC interaction is a conserved transcription regulatory mechanism among mammals, fish, flies, and other invertebrates.

  18. Transcription factor 19 interacts with histone 3 lysine 4 trimethylation and controls gluconeogenesis via the nucleosome-remodeling-deacetylase complex.

    Science.gov (United States)

    Sen, Sabyasachi; Sanyal, Sulagna; Srivastava, Dushyant Kumar; Dasgupta, Dipak; Roy, Siddhartha; Das, Chandrima

    2017-12-15

    Transcription factor 19 (TCF19) has been reported as a type 1 diabetes-associated locus involved in maintenance of pancreatic β cells through a fine-tuned regulation of cell proliferation and apoptosis. TCF19 also exhibits genomic association with type 2 diabetes, although the precise molecular mechanism remains unknown. It harbors both a plant homeodomain and a forkhead-associated domain implicated in epigenetic recognition and gene regulation, a phenomenon that has remained unexplored. Here, we show that TCF19 selectively interacts with histone 3 lysine 4 trimethylation through its plant homeodomain finger. Knocking down TCF19 under high-glucose conditions affected many metabolic processes, including gluconeogenesis. We found that TCF19 overexpression represses de novo glucose production in HepG2 cells. The transcriptional repression of key genes, induced by TCF19, coincided with NuRD (nucleosome-remodeling-deacetylase) complex recruitment to the promoters of these genes. TCF19 interacted with CHD4 (chromodomain helicase DNA-binding protein 4), which is a part of the NuRD complex, in a glucose concentration-independent manner. In summary, our results show that TCF19 interacts with an active transcription mark and recruits a co-repressor complex to regulate gluconeogenic gene expression in HepG2 cells. Our study offers critical insights into the molecular mechanisms of transcriptional regulation of gluconeogenesis and into the roles of chromatin readers in metabolic homeostasis. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  19. Hidradenocarcinoma of the finger.

    Science.gov (United States)

    Nazerali, Rahim S; Tan, Cynthia; Fung, Maxwell A; Chen, Steven L; Wong, Michael S

    2013-04-01

    Hidradenocarcinoma is a rare adnexal neoplasm representing the malignant counterpart of hidradenoma derived from eccrine sweat glands. Misdiagnosis of this disease is common due to the wide variety of histological patterns and rarity of this malignancy. We report an 87-year-old man presenting with a rare case of biopsy-proven hidradenocarcinoma of the finger. There is no standard care of treatment of hidradenocarcinoma, especially of those tumors in rare locations such as the fingers, given its rarity, variable tumor behavior and histology. Although limited treatment strategies exist, detailed data including TNM, location, histologic type and grade, and patient age should be gathered for optimal treatment strategy. The literature supports a 3-fold approach to these malignancies involving margin-free resection, sentinel lymph node biopsy to evaluate possible metastasis, and long-term follow-up given high risk of recurrence. Our treatment strategy involved a 4-fold, multidisciplinary approach involving reconstruction to optimize tumor-free remission and hand function.

  20. Adjustment to finger amputation and silicone finger prosthesis use.

    Science.gov (United States)

    Kuret, Zala; Burger, Helena; Vidmar, Gaj; Maver, Tomaz

    2018-01-11

    Finger amputations are the most common amputations of upper limbs. They influence hand function, general functioning and quality of life. One of the possibilities for rehabilitation after finger amputation is fitting a silicone finger prosthesis. We wanted to evaluate the adjustment to amputation and prosthesis use in patients after finger amputation. We included 42 patients with partial or complete single or multiple finger amputation of one hand who visited the outpatient clinic for prosthetics and orthotics at our institute and received a silicone prosthesis. We assessed their adjustment to amputation and prosthesis with the Trinity Amputation and Prosthesis Experience Scales (TAPES). Most of the patients (28, 67%) had a single finger amputated. The average scores on all TAPES subscales (except adjustment to limitation) were above 50% of the maximum possible score. On average, the scores were the highest on the general adjustment and satisfaction with the prosthesis subscales. Silicone prostheses for finger amputation of upper limb play an important role in the process of adaptation to amputation. They offer aesthetically satisfying results and alleviate social interactions, which influences overall quality of life. Implications for Rehabilitation Silicone prostheses for finger amputation of upper limb offer an aesthetically satisfying result and alleviate problems with social interactions. Their influence on hand function is not optimal, but the prosthesis improves the amputee's quality of life.

  1. Finger vein recognition based on finger crease location

    Science.gov (United States)

    Lu, Zhiying; Ding, Shumeng; Yin, Jing

    2016-07-01

    Finger vein recognition technology has significant advantages over other methods in terms of accuracy, uniqueness, and stability, and it has wide promising applications in the field of biometric recognition. We propose using finger creases to locate and extract an object region. Then we use linear fitting to overcome the problem of finger rotation in the plane. The method of modular adaptive histogram equalization (MAHE) is presented to enhance image contrast and reduce computational cost. To extract the finger vein features, we use a fusion method, which can obtain clear and distinguishable vein patterns under different conditions. We used the Hausdorff average distance algorithm to examine the recognition performance of the system. The experimental results demonstrate that MAHE can better balance the recognition accuracy and the expenditure of time compared with three other methods. Our resulting equal error rate throughout the total procedure was 3.268% in a database of 153 finger vein images.

  2. Eos negatively regulates human γ-globin gene transcription during erythroid differentiation.

    Directory of Open Access Journals (Sweden)

    Hai-Chuan Yu

    Full Text Available BACKGROUND: Human globin gene expression is precisely regulated by a complicated network of transcription factors and chromatin modifying activities during development and erythropoiesis. Eos (Ikaros family zinc finger 4, IKZF4, a member of the zinc finger transcription factor Ikaros family, plays a pivotal role as a repressor of gene expression. The aim of this study was to examine the role of Eos in globin gene regulation. METHODOLOGY/PRINCIPAL FINDINGS: Western blot and quantitative real-time PCR detected a gradual decrease in Eos expression during erythroid differentiation of hemin-induced K562 cells and Epo-induced CD34+ hematopoietic stem/progenitor cells (HPCs. DNA transfection and lentivirus-mediated gene transfer demonstrated that the enforced expression of Eos significantly represses the expression of γ-globin, but not other globin genes, in K562 cells and CD34+ HPCs. Consistent with a direct role of Eos in globin gene regulation, chromatin immunoprecipitaion and dual-luciferase reporter assays identified three discrete sites located in the DNase I hypersensitivity site 3 (HS3 of the β-globin locus control region (LCR, the promoter regions of the Gγ- and Aγ- globin genes, as functional binding sites of Eos protein. A chromosome conformation capture (3C assay indicated that Eos may repress the interaction between the LCR and the γ-globin gene promoter. In addition, erythroid differentiation was inhibited by enforced expression of Eos in K562 cells and CD34+ HPCs. CONCLUSIONS/SIGNIFICANCE: Our results demonstrate that Eos plays an important role in the transcriptional regulation of the γ-globin gene during erythroid differentiation.

  3. Identification of Quaternary Structure and Functional Domains of the CI Repressor from Bacteriophage TP901-1

    DEFF Research Database (Denmark)

    Pedersen, Margit; Lo Leggio, Leila; Grossmann, J. Günter

    2008-01-01

    -L and the lysogenic promoter PR by binding to multiple operator sites on the DNA. In this study, we used a small bistable genetic switch element from phage TP901-1 to study the effect of cI deletions in vivo and showed that 43 amino acids could be removed from the C-terminal end of Cl without destroying the ability......The bacteriophage-encoded repressor protein plays a key role in determining the life cycle of a temperate phage following infection of a sensitive host. The repressor protein Cl, which is encoded by the temperate lactococcal phage TP901-1, represses transcription from both the lytic promoter P...

  4. Emotional Communication in Finger Braille

    Directory of Open Access Journals (Sweden)

    Yasuhiro Matsuda

    2010-01-01

    Full Text Available We describe analyses of the features of emotions (neutral, joy, sadness, and anger expressed by Finger Braille interpreters and subsequently examine the effectiveness of emotional expression and emotional communication between people unskilled in Finger Braille. The goal is to develop a Finger Braille system to teach emotional expression and a system to recognize emotion. The results indicate the following features of emotional expression by interpreters. The durations of the code of joy were significantly shorter than the durations of the other emotions, the durations of the code of sadness were significantly longer, and the finger loads of anger were significantly larger. The features of emotional expression by unskilled subjects were very similar to those of the interpreters, and the coincidence ratio of emotional communication was 75.1%. Therefore, it was confirmed that people unskilled in Finger Braille can express and communicate emotions using this communication medium.

  5. Regulation of the Ets transcription factor Tel

    NARCIS (Netherlands)

    Roukens, Mark Guido

    2010-01-01

    In this thesis we report novel studies on the molecular regulation of the transcriptional repressor Tel (Translocation Ets Leukemia). The work in this thesis is presented as follows: Chapter 1 is an introduction which summarizes the literature about Tel and its Drosophila orthologue Yan as it was

  6. Chimeric repressor of PtSND2 severely affects wood formation in transgenic Populus.

    Science.gov (United States)

    Wang, H H; Tang, R J; Liu, H; Chen, H Y; Liu, J Y; Jiang, X N; Zhang, H X

    2013-08-01

    NAC domain transcription factors are important regulators that activate the secondary wall biosynthesis in wood formation. In this work, we investigated the possible functions of an NAC family member SECONDARY WALL-ASSOCIATED NAC DOMAIN PROTEIN2 (PtSND2) using chimeric repressor silencing technology. Reverse transcription-polymerase chain reaction, subcellular localization and transcriptional activation analyses indicated that PtSND2 is a wood-associated transcriptional factor with the predicted transcriptional activation activity, which could be inhibited by the repression domain SUPERMAN REPRESSION DOMAIN X (SRDX) in yeast. Wood formation was severely repressed in transgenic poplar plants overexpressing PtSND2-SRDX. Meanwhile, the secondary cell wall thickness of xylem fibers was restrained, and the contents of cellulose and lignin were obviously decreased in the stems of transgenic plants. Further studies indicated that expressions of a number of wood-associated genes were down-regulated in the stems of transgenic plants. Our results suggest that PtSND2 may play important roles during the secondary growth of stems in poplar.

  7. Repressor-mediated tissue-specific gene expression in plants

    Science.gov (United States)

    Meagher, Richard B [Athens, GA; Balish, Rebecca S [Oxford, OH; Tehryung, Kim [Athens, GA; McKinney, Elizabeth C [Athens, GA

    2009-02-17

    Plant tissue specific gene expression by way of repressor-operator complexes, has enabled outcomes including, without limitation, male sterility and engineered plants having root-specific gene expression of relevant proteins to clean environmental pollutants from soil and water. A mercury hyperaccumulation strategy requires that mercuric ion reductase coding sequence is strongly expressed. The actin promoter vector, A2pot, engineered to contain bacterial lac operator sequences, directed strong expression in all plant vegetative organs and tissues. In contrast, the expression from the A2pot construct was restricted primarily to root tissues when a modified bacterial repressor (LacIn) was coexpressed from the light-regulated rubisco small subunit promoter in above-ground tissues. Also provided are analogous repressor operator complexes for selective expression in other plant tissues, for example, to produce male sterile plants.

  8. Activation of Fetal γ-globin Gene Expression via Direct Protein Delivery of Synthetic Zinc-finger DNA-Binding Domains

    Directory of Open Access Journals (Sweden)

    Mir A Hossain

    2016-01-01

    Full Text Available Reactivation of γ-globin expression has been shown to ameliorate disease phenotypes associated with mutations in the adult β-globin gene, including sickle cell disease. Specific mutations in the promoter of the γ-globin genes are known to prevent repression of the genes in the adult and thus lead to hereditary persistence of fetal hemoglobin. One such hereditary persistence of fetal hemoglobin is associated with a sequence located 567 bp upstream of the Gγ-globin gene which assembles a GATA-containing repressor complex. We generated two synthetic zinc-finger DNA-binding domains (ZF-DBDs targeting this sequence. The -567Gγ ZF-DBDs associated with high affinity and specificity with the target site in the γ-globin gene promoter. We delivered the -567Gγ ZF-DBDs directly to primary erythroid cells. Exposure of these cells to the recombinant -567Gγ ZF-DBDs led to increased expression of the γ-globin gene. Direct protein delivery of ZF-DBDs that compete with transcription regulatory proteins will have broad implications for modulating gene expression in analytical or therapeutic settings.

  9. DNA residence time is a regulatory factor of transcription repression.

    Science.gov (United States)

    Clauß, Karen; Popp, Achim P; Schulze, Lena; Hettich, Johannes; Reisser, Matthias; Escoter Torres, Laura; Uhlenhaut, N Henriette; Gebhardt, J Christof M

    2017-11-02

    Transcription comprises a highly regulated sequence of intrinsically stochastic processes, resulting in bursts of transcription intermitted by quiescence. In transcription activation or repression, a transcription factor binds dynamically to DNA, with a residence time unique to each factor. Whether the DNA residence time is important in the transcription process is unclear. Here, we designed a series of transcription repressors differing in their DNA residence time by utilizing the modular DNA binding domain of transcription activator-like effectors (TALEs) and varying the number of nucleotide-recognizing repeat domains. We characterized the DNA residence times of our repressors in living cells using single molecule tracking. The residence times depended non-linearly on the number of repeat domains and differed by more than a factor of six. The factors provoked a residence time-dependent decrease in transcript level of the glucocorticoid receptor-activated gene SGK1. Down regulation of transcription was due to a lower burst frequency in the presence of long binding repressors and is in accordance with a model of competitive inhibition of endogenous activator binding. Our single molecule experiments reveal transcription factor DNA residence time as a regulatory factor controlling transcription repression and establish TALE-DNA binding domains as tools for the temporal dissection of transcription regulation. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  10. [Multiple finger geodes in children].

    Science.gov (United States)

    Hoeffel, J C; Oprisescu, B; Bresson, A; Ploier, R; Vidailhet, M

    1993-06-01

    Three pediatric patients with multiple geodes in the fingers are reported. This condition occurs mainly between one and three years and at seven years of age and is more common in winter. Affected fingers are swollen. Roentgenograms disclose several small lucent defects which are usually located in the middle phalanx. Several fingers are usually involved. The erythrocyte sedimentation rate is increased in virtually every case. Resolution occurs spontaneously within a few weeks or months. There is no tendency towards recurrence. Although the condition is inflammatory, exposure to cold is probably a precipitating factor.

  11. The Molecular Switch of Telomere Phages: High Binding Specificity of the PY54 Cro Lytic Repressor to a Single Operator Site

    Science.gov (United States)

    Hammerl, Jens Andre; Roschanski, Nicole; Lurz, Rudi; Johne, Reimar; Lanka, Erich; Hertwig, Stefan

    2015-01-01

    Temperate bacteriophages possess a molecular switch, which regulates the lytic and lysogenic growth. The genomes of the temperate telomere phages N15, PY54 and ϕKO2 harbor a primary immunity region (immB) comprising genes for the prophage repressor, the lytic repressor and a putative antiterminator. The roles of these products are thought to be similar to those of the lambda proteins CI, Cro and Q, respectively. Moreover, the gene order and the location of several operator sites in the prototype telomere phage N15 and in ϕKO2 are also reminiscent of lambda-like phages. By contrast, in silico analyses revealed the presence of only one operator (OR3) in PY54. The purified PY54 Cro protein was used for EMSA studies demonstrating that it exclusively binds to a 16-bp palindromic site (OR3) upstream of the prophage repressor gene. The OR3 operator sequences of PY54 and ϕKO2/N15 only differ by their peripheral base pairs, which are responsible for Cro specificity. PY54 cI and cro transcription is regulated by highly active promoters initiating the synthesis of a homogenious species of leaderless mRNA. The location of the PY54 Cro binding site and of the identified promoters suggests that the lytic repressor suppresses cI transcription but not its own synthesis. The results indicate an unexpected diversity of the growth regulation mechanisms in lambda-related phages. PMID:26043380

  12. Dynamic allostery in the methionine repressor revealed by force distribution analysis.

    Directory of Open Access Journals (Sweden)

    Wolfram Stacklies

    2009-11-01

    Full Text Available Many fundamental cellular processes such as gene expression are tightly regulated by protein allostery. Allosteric signal propagation from the regulatory to the active site requires long-range communication, the molecular mechanism of which remains a matter of debate. A classical example for long-range allostery is the activation of the methionine repressor MetJ, a transcription factor. Binding of its co-repressor SAM increases its affinity for DNA several-fold, but has no visible conformational effect on its DNA binding interface. Our molecular dynamics simulations indicate correlated domain motions within MetJ, and quenching of these dynamics upon SAM binding entropically favors DNA binding. From monitoring conformational fluctuations alone, it is not obvious how the presence of SAM is communicated through the largely rigid core of MetJ and how SAM thereby is able to regulate MetJ dynamics. We here directly monitored the propagation of internal forces through the MetJ structure, instead of relying on conformational changes as conventionally done. Our force distribution analysis successfully revealed the molecular network for strain propagation, which connects collective domain motions through the protein core. Parts of the network are directly affected by SAM binding, giving rise to the observed quenching of fluctuations. Our results are in good agreement with experimental data. The force distribution analysis suggests itself as a valuable tool to gain insight into the molecular function of a whole class of allosteric proteins.

  13. The κB transcriptional enhancer motif and signal sequences of V(DJ recombination are targets for the zinc finger protein HIVEP3/KRC: a site selection amplification binding study

    Directory of Open Access Journals (Sweden)

    Wu Lai-Chu

    2002-08-01

    Full Text Available Abstract Background The ZAS family is composed of proteins that regulate transcription via specific gene regulatory elements. The amino-DNA binding domain (ZAS-N and the carboxyl-DNA binding domain (ZAS-C of a representative family member, named κB DNA binding and recognition component (KRC, were expressed as fusion proteins and their target DNA sequences were elucidated by site selection amplification binding assays, followed by cloning and DNA sequencing. The fusion proteins-selected DNA sequences were analyzed by the MEME and MAST computer programs to obtain consensus motifs and DNA elements bound by the ZAS domains. Results Both fusion proteins selected sequences that were similar to the κB motif or the canonical elements of the V(DJ recombination signal sequences (RSS from a pool of degenerate oligonucleotides. Specifically, the ZAS-N domain selected sequences similar to the canonical RSS nonamer, while ZAS-C domain selected sequences similar to the canonical RSS heptamer. In addition, both KRC fusion proteins selected oligonucleoties with sequences identical to heptamer and nonamer sequences within endogenous RSS. Conclusions The RSS are cis-acting DNA motifs which are essential for V(DJ recombination of antigen receptor genes. Due to its specific binding affinity for RSS and κB-like transcription enhancer motifs, we hypothesize that KRC may be involved in the regulation of V(DJ recombination.

  14. Structure and dynamics in Lac repressor-DNA interactions

    NARCIS (Netherlands)

    Kaptein, R.

    2013-01-01

    The E. coli lac operon is the classical model for gene regulation in bacteria. An overview will be given of our work on the lac repressor-operator system. An early result was the 3D structure of lac headpiece in 1985, one of the first protein structures determined by NMR. Our studies of the

  15. NMR studies on DNA binding specificity of the lac repressor

    NARCIS (Netherlands)

    Kopke Salinas, Roberto

    2005-01-01

    The thesis describes NMR structures of two protein-DNA complexes. The first structure shows how the protein, the DNA binding domain of lac repressor, recognizes its natural DNA binding site, by adaptation and read out of the nucleotide sequence. The second one shows how the DNA binding specificity

  16. Overlapping repressor binding sites regulate expression of the Methanococcus maripaludis glnK1 operon

    Science.gov (United States)

    Lie, Thomas J.; Hendrickson, Erik L.; Niess, Ulf M.; Moore, Brian C.; Haydock, Andrew K.; Leigh, John A.

    2011-01-01

    The euryarchaeal transcriptional repressor NrpR regulates a variety of nitrogen assimilation genes by 2-oxoglutarate-reversible binding to conserved palindromic operators. The number and positioning of these operators varies among promoter regions of regulated genes, suggesting NrpR can bind in different patterns. Particularly intriguing is the contrast between the nif and glnK1 promoter regions of Methanococcus maripaludis, where two operators are present but with different configurations. Here we study NrpR binding and regulation at the glnK1 promoter, where the two operator sequences overlap and occur on opposite faces of the double helix. We find that both operators function in binding, with a dimer of NrpR binding simultaneously to each overlapping operator. We show in vivo that the first operator plays a primary role in regulation and the second operator plays an enhancing role. This is the first demonstration of overlapping operators functioning in Archaea. PMID:20025661

  17. Overlapping repressor binding sites regulate expression of the Methanococcus maripaludis glnK(1) operon.

    Science.gov (United States)

    Lie, Thomas J; Hendrickson, Erik L; Niess, Ulf M; Moore, Brian C; Haydock, Andrew K; Leigh, John A

    2010-02-01

    The euryarchaeal transcriptional repressor NrpR regulates a variety of nitrogen assimilation genes by 2-oxoglutarate-reversible binding to conserved palindromic operators. The number and positioning of these operators varies among promoter regions of regulated genes, suggesting NrpR can bind in different patterns. Particularly intriguing is the contrast between the nif and glnK(1) promoter regions of Methanococcus maripaludis, where two operators are present but with different configurations. Here we study NrpR binding and regulation at the glnK(1) promoter, where the two operator sequences overlap and occur on opposite faces of the double helix. We find that both operators function in binding, with a dimer of NrpR binding simultaneously to each overlapping operator. We show in vivo that the first operator plays a primary role in regulation and the second operator plays an enhancing role. This is the first demonstration of overlapping operators functioning in Archaea.

  18. Kaiso Directs the Transcriptional Corepressor MTG16 to the Kaiso Binding Site in Target Promoters

    Science.gov (United States)

    Barrett, Caitlyn W.; Smith, J. Joshua; Lu, Lauren C.; Markham, Nicholas; Stengel, Kristy R.; Short, Sarah P.; Zhang, Baolin; Hunt, Aubrey A.; Fingleton, Barbara M.; Carnahan, Robert H.; Engel, Michael E.; Chen, Xi; Beauchamp, R. Daniel; Wilson, Keith T.; Hiebert, Scott W.; Reynolds, Albert B.; Williams, Christopher S.

    2012-01-01

    Myeloid translocation genes (MTGs) are transcriptional corepressors originally identified in acute myelogenous leukemia that have recently been linked to epithelial malignancy with non-synonymous mutations identified in both MTG8 and MTG16 in colon, breast, and lung carcinoma in addition to functioning as negative regulators of WNT and Notch signaling. A yeast two-hybrid approach was used to discover novel MTG binding partners. This screen identified the Zinc fingers, C2H2 and BTB domain containing (ZBTB) family members ZBTB4 and ZBTB38 as MTG16 interacting proteins. ZBTB4 is downregulated in breast cancer and modulates p53 responses. Because ZBTB33 (Kaiso), like MTG16, modulates Wnt signaling at the level of TCF4, and its deletion suppresses intestinal tumorigenesis in the ApcMin mouse, we determined that Kaiso also interacted with MTG16 to modulate transcription. The zinc finger domains of Kaiso as well as ZBTB4 and ZBTB38 bound MTG16 and the association with Kaiso was confirmed using co-immunoprecipitation. MTG family members were required to efficiently repress both a heterologous reporter construct containing Kaiso binding sites (4×KBS) and the known Kaiso target, Matrix metalloproteinase-7 (MMP-7/Matrilysin). Moreover, chromatin immunoprecipitation studies placed MTG16 in a complex occupying the Kaiso binding site on the MMP-7 promoter. The presence of MTG16 in this complex, and its contributions to transcriptional repression both required Kaiso binding to its binding site on DNA, establishing MTG16-Kaiso binding as functionally relevant in Kaiso-dependent transcriptional repression. Examination of a large multi-stage CRC expression array dataset revealed patterns of Kaiso, MTG16, and MMP-7 expression supporting the hypothesis that loss of either Kaiso or MTG16 can de-regulate a target promoter such as that of MMP-7. These findings provide new insights into the mechanisms of transcriptional control by ZBTB family members and broaden the scope of co-repressor

  19. Brain REST/NRSF Is Not Only a Silent Repressor but Also an Active Protector.

    Science.gov (United States)

    Zhao, Yangang; Zhu, Min; Yu, Yanlan; Qiu, Linli; Zhang, Yuanyuan; He, Li; Zhang, Jiqiang

    2017-01-01

    During neurogenesis, specific transcription factors are needed to repress neuronal genes in nonneuronal cells to ensure precise development. Repressor element-1 binding transcription factor (REST), or neuron-restrictive silencer factor (NRSF), has been shown to be an important regulator for the establishment of neuronal specificity. It restricts the expression of neuronal genes by binding to the neuron-restrictive silencer element (NRSE/RE1) domain in neuron-specific genes. REST/NRSF regulates many target genes in stem cells, nonneural cells, and neurons, which are involved in neuronal differentiation, axonal growth, vesicular transport, and release as well as ionic conductance. However, it is also regulated by some cytokines/regulators such as epigenetic factors (microRNAs) and even its truncated isoform. REST/NRSF is widely detected in brain regions and has been shown to be highly expressed in nonneuronal cells, but current findings also reveal that, at least in the human brain, it is also highly expressed in neurons and increases with ageing. However, its loss in expression and cytoplasmic translocation seems to play a pivotal role in several human dementias. Additionally, REST/NRSF knockdown leads to malformations in nerve and nonneural tissues and embryonic lethality. Altered REST/NRSF expression has been not only related to deficient brain functions such as neurodegenerative diseases, mental disorders, brain tumors, and neurobehavioral disorders but also highly correlated to brain injuries such as alcoholism and stroke. Encouragingly, several compounds such as valproic acid and X5050 that target REST/NRSF have been shown to be clinically effective at rescuing seizures or Niemann-Pick type C disease. Surprisingly, studies have also shown that REST/NRSF can function as an activator to induce neuronal differentiation. These findings strongly indicate that REST/NRSF is not only a classical repressor to maintain normal neurogenesis, but it is also a fine

  20. Regulation of Escherichia coli purA by purine repressor, one component of a dual control mechanism.

    OpenAIRE

    He, B; Zalkin, H

    1994-01-01

    Escherichia coli purA encodes adenylosuccinate synthetase, one of two enzymes required for synthesis of AMP from IMP. purA is subject to two- to threefold regulation by purR and about twofold regulation by a purR-independent mechanism. The 5'-flanking region of purA confers purR-dependent transcriptional regulation of purA but not the purR-independent regulation. Two operator sites in the 5'-flanking region which bind purine repressor in vitro and are required for in vivo regulation were iden...

  1. Involvement of co-repressor LUH and the adapter proteins SLK1 and SLK2 in the regulation of abiotic stress response genes in Arabidopsis.

    Science.gov (United States)

    Shrestha, Barsha; Guragain, Bhuwan; Sridhar, Vaniyambadi V

    2014-02-24

    During abiotic stress many genes that are important for growth and adaptation to stress are expressed at elevated levels. However, the mechanisms that keep the stress responsive genes from expressing under non stress conditions remain elusive. Recent genetic characterization of the co-repressor LEUNIG_HOMOLOG (LUH) and transcriptional adaptor proteins SEUSS-LIKE1 (SLK1) and SLK2 have been proposed to function redundantly in diverse developmental processes; however their function in the abiotic stress response is unknown. Moreover, the molecular functions of LUH, SLK1 and SLK2 remain obscure. Here, we show the molecular function of LUH, SLK1 and SLK2 and the role of this complex in the abiotic stress response. The luh, slk1 and slk2 mutant plants shows enhanced tolerance to salt and osmotic stress conditions. SLK1 and SLK2 interact physically with the LUFS domain in LUH forming SLK1-LUH and SLK2-LUH co-repressor complexes to inhibit the transcription. LUH has repressor activity, whereas SLK1 and SLK2 function as adaptors to recruit LUH, which in turn recruits histone deacetylase to the target sequences to repress transcription. The stress response genes RD20, MYB2 and NAC019 are expressed at elevated levels in the luh, slk1 and slk2 mutant plants. Furthermore, these stress response genes are associated with decreased nucleosome density and increased acetylation levels at H3K9 and H3K14 in the luh, slk1 and slk2 mutant plants. Our results indicate that SLK1, SLK2 and LUH form a co-repressor complex. LUH represses by means of an epigenetic process involving histone modification to facilitate the condensation of chromatin thus preventing transcription at the target genes.

  2. SarT, a Repressor of α-Hemolysin in Staphylococcus aureus

    Science.gov (United States)

    Schmidt, Katherine A.; Manna, Adhar C.; Gill, Steven; Cheung, Ambrose L.

    2001-01-01

    In searching the Staphylococcus aureus genome, we found several homologs to SarA. One of these genes, sarT, codes for a basic protein with 118 residues and a predicted molecular size of 16,096 Da. Northern blot analysis revealed that the expression of sarT was repressed by sarA and agr. An insertion sarT mutant generated in S. aureus RN6390 and 8325-4 backgrounds revealed minimal effect on the expression of sarR and sarA. The RNAIII level was notably increased in the sarT mutant, particularly in postexponential-phase cells, while the augmentative effect on RNAII was less. SarT repressed the expression of α-hemolysin, as determined by Northern blotting, Western blotting, and a rabbit erythrocyte hemolytic assay. This repression was relieved upon complementation. Similar to agr and sarA mutants, which predictably displayed a reduction in hla expression, the agr sarT mutant exhibited a lower level of hla transcription than the sarT mutant. In contrast, hla transcription was enhanced in the sarA sarT mutant compared with the single sarA mutant. Collectively, these results indicated that the sarA locus, contrary to the regulatory action of agr, induced α-hemolysin production by repressing sarT, a repressor of hla transcription. PMID:11447147

  3. Identification of novel transcription factors regulating secondary cell wall formation in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Hua eCassan-Wang

    2013-06-01

    Full Text Available The presence of lignin in secondary cell walls (SCW is a major factor preventing hydrolytic enzymes from gaining access to cellulose, thereby limiting the saccharification potential of plant biomass. To understand how lignification is regulated is a prerequisite for selecting plant biomass better adapted to bioethanol production. Because transcriptional regulation is a major mechanism controlling the expression of genes involved in lignin biosynthesis, our aim was to identify novel transcription factors dictating lignin profiles in the model plant Arabidopsis. To this end, we have developed a post-genomic approach by combining four independent in-house SCW-related transcriptome datasets obtained from (i the fiber cell wall-deficient wat1 Arabidopsis mutant, (ii Arabidopsis lines over-expressing either the master regulatory activator EgMYB2 or (iii the repressor EgMYB1 and finally (iv Arabidopsis orthologs of Eucalyptus xylem-expressed genes. This allowed us to identify 502 up- or down-regulated transcription factors. We preferentially selected those present in more than one dataset and further analyzed their in silico expression patterns as an additional selection criteria. This selection process led to 80 candidates. Notably, 16 of them were already proven to regulate SCW formation, thereby validating the overall strategy. Then, we phenotyped 43 corresponding mutant lines focusing on histological observations of xylem and interfascicular fibers. This phenotypic screen revealed six mutant lines exhibiting altered lignification patterns. Two of them (blh6 and a zinc finger transcription factor presented hypolignified SCW. Three others (myb52, myb-like TF, hb5 showed hyperlignified SCW whereas the last one (hb15 showed ectopic lignification. In addition, our meta-analyses highlighted a reservoir of new potential regulators adding to the gene network regulating SCW but also opening new avenues to ultimately improve SCW composition for biofuel

  4. Crystal Structure of the Lactose Operon Repressor and Its Complexes with DNA and Inducer

    Science.gov (United States)

    Lewis, Mitchell; Chang, Geoffrey; Horton, Nancy C.; Kercher, Michele A.; Pace, Helen C.; Schumacher, Maria A.; Brennan, Richard G.; Lu, Ponzy

    1996-03-01

    The lac operon of Escherichia coli is the paradigm for gene regulation. Its key component is the lac repressor, a product of the lacI gene. The three-dimensional structures of the intact lac repressor, the lac repressor bound to the gratuitous inducer isopropyl-β-D-1-thiogalactoside (IPTG) and the lac repressor complexed with a 21-base pair symmetric operator DNA have been determined. These three structures show the conformation of the molecule in both the induced and repressed states and provide a framework for understanding a wealth of biochemical and genetic information. The DNA sequence of the lac operon has three lac repressor recognition sites in a stretch of 500 base pairs. The crystallographic structure of the complex with DNA suggests that the tetrameric repressor functions synergistically with catabolite gene activator protein (CAP) and participates in the quaternary formation of repression loops in which one tetrameric repressor interacts simultaneously with two sites on the genomic DNA.

  5. Binding of the N-Terminal Domain of the Lactococcal Bacteriophage TP901-1 CI Repressor to Its Target DNA: A Crystallography, Small Angle Scattering, and Nuclear Magnetic Resonance Study

    DEFF Research Database (Denmark)

    Frandsen, Kristian Erik Høpfner; Rasmussen, Kim K.; Jensen, Malene Ringkjøbing

    2013-01-01

    In most temperate bacteriophages, regulation of the choice of lysogenic or lytic life cycle is controlled by a CI repressor protein. Inhibition of transcription is dependent on a helix–turn–helix motif, often located in the N-terminal domain (NTD), which binds to specific DNA sequences (operator ...

  6. Pokemon decreases the transcriptional activity of RARα in the absence of ligand.

    Science.gov (United States)

    Yang, Yutao; Li, Yueting; Di, Fei; Cui, Jiajun; Wang, Yue; David Xu, Zhi-Qing

    2016-12-20

    Pokemon is a transcriptional repressor that belongs to the POZ and Krüppel (POK) protein family. In this study, we investigated the potential interaction between Pokemon and retinoic acid receptor alpha (RARα) and determined the role of Pokemon in regulation of RARα transcriptional activity in the absence of ligand. We found that Pokemon could directly interact with RARα. Moreover, we demonstrated that Pokemon could decrease the transcriptional activity of RARα in the absence of ligand. Furthermore, we showed that Pokemon could repress the transcriptional activity of RARα by increasing the recruitment of nuclear receptor co-repressor (NCoR) and silencing mediator of retinoic acid and thyroid hormone receptor (SMRT) to the retinoic acid response element (RARE) element. Taken together, these data suggest that Pokemon is a novel partner of RARα that acts as a co-repressor to regulate RARα transcriptional activity in the absence of ligand.

  7. Mesofluidic controlled robotic or prosthetic finger

    Science.gov (United States)

    Lind, Randall F; Jansen, John F; Love, Lonnie J

    2013-11-19

    A mesofluidic powered robotic and/or prosthetic finger joint includes a first finger section having at least one mesofluidic actuator in fluid communication with a first actuator, a second mesofluidic actuator in fluid communication with a second actuator and a second prosthetic finger section pivotally connected to the first finger section by a joint pivot, wherein the first actuator pivotally cooperates with the second finger to provide a first mechanical advantage relative to the joint point and wherein the second actuator pivotally cooperates with the second finger section to provide a second mechanical advantage relative to the joint point.

  8. [Finger extension. II. Materials and methods].

    Science.gov (United States)

    Kuhlmann, J N; Boabighi, A; Laudet, C; Guerin-Surville, H; Baux, S

    1992-06-01

    The study of the extensor apparatus through different methods concerns 200 fingers, the most of fresh cadavers. The dissection through direct observation or with surgical microscope of the dorsal aponeurosis of 30 fingers has been completed by an histological study of 10 fingers. The mechanic properties of each dorsal aponeurotic structure has been tested by extensometry on 12 fingers. The functional study of the role and of the transmission of the different motor components concerns 128 fingers. It has been completed by experimental sections of each aponeurotic structure concerning 20 fingers.

  9. 2,3,7,8-Tetrachlorodibenzo-p-dioxin poly(ADP-ribose) polymerase (TiPARP, ARTD14) is a mono-ADP-ribosyltransferase and repressor of aryl hydrocarbon receptor transactivation.

    Science.gov (United States)

    MacPherson, Laura; Tamblyn, Laura; Rajendra, Sharanya; Bralha, Fernando; McPherson, J Peter; Matthews, Jason

    2013-02-01

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD)-inducible poly(ADP-ribose) polymerase (TiPARP/ARTD14) is a member of the PARP family and is regulated by the aryl hydrocarbon receptor (AHR); however, little is known about TiPARP function. In this study, we examined the catalytic function of TiPARP and determined its role in AHR transactivation. We observed that TiPARP exhibited auto-mono-ADP-ribosyltransferase activity and ribosylated core histones. RNAi-mediated knockdown of TiPARP in T-47D breast cancer and HuH-7 hepatoma cells increased TCDD-dependent cytochrome P450 1A1 (CYP1A1) and CYP1B1 messenger RNA (mRNA) expression levels and recruitment of AHR to both genes. Overexpression of TiPARP reduced AHR-dependent increases in CYP1A1-reporter gene activity, which was restored by overexpression of AHR, but not aryl hydrocarbon receptor nuclear translocator. Deletion and mutagenesis studies showed that TiPARP-mediated inhibition of AHR required the zinc-finger and catalytic domains. TiPARP and AHR co-localized in the nucleus, directly interacted and both were recruited to CYP1A1 in response to TCDD. Overexpression of Tiparp enhanced, whereas RNAi-mediated knockdown of TiPARP reduced TCDD-dependent AHR proteolytic degradation. TCDD-dependent induction of AHR target genes was enhanced in Tiparp(-/-) mouse embryonic fibroblasts compared with wildtype controls. Our findings show that TiPARP is a mono-ADP-ribosyltransferase and a transcriptional repressor of AHR, revealing a novel negative feedback loop in AHR signalling.

  10. Chemical modification of arginine residues in the lactose repressor

    International Nuclear Information System (INIS)

    Whitson, P.A.; Matthews, K.S.

    1987-01-01

    The lactose repressor protein was chemically modified with 2,3-butanedione and phenylglyoxal. Arginine reaction was quantitated by either amino aced analysis or incorporation of 14 C-labeled phenylglyoxal. Inducer binding activity was unaffected by the modification of arginine residues, while both operator and nonspecific DNA binding activities were diminished, although to differing degrees. The correlation of the decrease in DNA binding activities with the modification of ∼ 1-2 equiv of arginine per monomer suggests increased reactivity of a functionally essential residue(s). For both reagents, operator DNA binding activity was protected by the presence of calf thymus DNA, and the extent of reaction with phenylglyoxal was simultaneously diminished. This protection presumably results from steric restriction of reagent access to an arginine(s) that is (are) essential for DNA binding interactions. These experiments suggest that there is (are) an essential reactive arginine(s) critical for repressor binding to DNA

  11. Plasticity in Repressor-DNA Interactions Neutralizes Loss of Symmetry in Bipartite Operators.

    Science.gov (United States)

    Jain, Deepti; Narayanan, Naveen; Nair, Deepak T

    2016-01-15

    Transcription factor-DNA interactions are central to gene regulation. Many transcription factors regulate multiple target genes and can bind sequences that do not conform strictly to the consensus. To understand the structural mechanism utilized by the transcription regulators to bind diverse target sequences, we have employed the repressor AraR from Bacillus subtilis as a model system. AraR is known to bind to eight different operator sites in the bacterial genome. Although there are differences in the sequences of four of these operators, ORE1, ORX1, ORA1, and ORR3, the AraR-DNA binding domain (AraR-DBD) as well as full-length AraR unexpectedly binds to each of these sequences with similar affinities as measured by fluorescence anisotropy experiments. We have determined crystal structures of AraR-DBD in complex with two different natural operators ORE1 and ORX1 up to 2.07 and 1.97 Å resolution, respectively. These structures were compared with the previously reported structures of AraR-DBD bound to two other natural operators (ORA1 and ORR3). Interactions of two molecules of AraR-DBD with the symmetric operator, ORE1, are identical, but their interaction with the non-symmetric operator ORX1 results in breakdown of the symmetry in protein-DNA interactions. The novel interactions observed are accompanied by local conformational change in the DNA. ChIP-sequencing (ChIP-Seq) data on other transcription factors has shown that they can bind to diverse targets, and hence the plasticity exhibited by AraR may be a general phenomenon. The ability of transcription factors to form alternate interactions may be important for employment in new functions and evolution of novel regulatory circuits. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  12. TRIM45, a novel human RBCC/TRIM protein, inhibits transcriptional activities of ElK-1 and AP-1

    International Nuclear Information System (INIS)

    Wang Yuequn; Li Yongqing; Qi Xinzhu; Yuan Wuzhou; Ai Jianping; Zhu Chuanbing; Cao Lei; Yang Hong; Liu Fang; Wu Xiushan; Liu Mingyao

    2004-01-01

    The tripartite motif (TRIM) proteins play important roles in a variety of cellular functions including cell proliferation, differentiation, development, oncogenesis, and apoptosis. In this study, we report the identification and characterization of the human tripartite motif-containing protein 45 (TRIM45), a novel member of the TRIM family, from a human embryonic heart cDNA library. TRIM45 has a predicted 580 amino acid open reading frame, encoding a putative 64-kDa protein. The N-terminal region harbors a RING finger, two B-boxes, and a predicted α-helical coiled-coil domain, which together form the RBCC/TRIM motif found in a large family of proteins, whereas the C-terminal region contains a filamin-type immunoglobulin (IG-FLMN) domain. Northern blot analysis indicates that TRIM45 is expressed in a variety of human adult and embryonic tissues. In the cell, TRIM45 protein is expressed both in cytoplasm and in cell nucleus. Overexpression of TRIM45 in COS-7 cells inhibits the transcriptional activities of ElK-1 and AP-1. These results suggest that TRIM45 may act as a new transcriptional repressor in mitogen-activated protein kinase signaling pathway

  13. X-Ray Exam: Finger

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español X-Ray Exam: Finger KidsHealth / For Parents / X-Ray Exam: ... Muscles, and Joints Broken Bones Getting an X-ray (Video) X-Ray (Video) View more Partner Message About Us ...

  14. Activation of pur Gene Expression by a Homologue of the Bacillus subtilis PurR repressor:

    DEFF Research Database (Denmark)

    Kilstrup, Mogens; Martinussen, Jan

    1998-01-01

    A purR::pGh9:Iss1 mutant was obtained in Lactococcus lactis following transposon mutagenesis of strain MG1363 and selection for purine auxotrophs. After determination of the nucleotide sequence and deduction of the purR reading frame, the PurR product was found to be highly similar to the pur......R encoded repressor from Bacillus subtilis. The wildtype purR gene complements the purine auxotrophy of a purR::Iss1mutant, and it was shown that the purR::Iss1 mutation lowers transcription from the purine regulated L. lactis purD promoter. In a parallel study on the regulation of purC and purD expression...... in L. lactis (Accompanying report) we identified regions (PurBox sequences: AwwwCCGAACwwT) upstream of the promoters, with the central G-residue at exactly position –76 relative to the transcriptional start site. The PurBox’es were found to be required for high promoter activity and purine regulation...

  15. The cytidine repressor participates in the regulatory pathway of indole in Pantoea agglomerans.

    Science.gov (United States)

    Jia, Mengqi; Yu, Xuemei; Jiang, Jing; Li, Zihua; Feng, Yongjun

    2017-09-01

    Indole, an important signal molecule in both intraspecies and interspecies, regulates a variety of bacterial behaviors, but its regulatory mechanism is still unknown. Pantoea agglomerans YS19, a preponderant endophytic bacterium isolated from rice, does not produce indole, yet it senses exogenous indole. In this study, a mutant of YS19-Rp r whose target gene expression was downregulated by indole was selected through mTn5 transposon mutagenesis. Using the TAIL-PCR technique, the mutation gene was identified as a cytR homologue, which encodes a cytidine repressor (CytR) protein, a bacterial transcription factor involved in a complex regulation scheme. The negative regulation of indole in cytR, which is equivalent to the mutation in cytR, promotes the expression of a downstream gene deoC, which encodes the key enzyme deoxyribose-phosphate aldolase in participating in pentose metabolism. We found that DeoC is one of the regulatory proteins of P. agglomerans that is involved in counteracting starvation. Furthermore, the expression of deoC was induced by starvation conditions, accompanied by a decrease in cytR expression. This finding suggests that the indole signal and the mutation of cytR relieve inhibition of CytR in the transcription of deoC, facilitating better adaptation of the bacterium to the adverse conditions of the environment. Copyright © 2017 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  16. Genome-wide RIP-Chip analysis of translational repressor-bound mRNAs in the Plasmodium gametocyte

    KAUST Repository

    Guerreiro, Ana

    2014-11-03

    Background Following fertilization, the early proteomes of metazoans are defined by the translation of stored but repressed transcripts; further embryonic development relies on de novo transcription of the zygotic genome. During sexual development of Plasmodium berghei, a rodent model for human malaria species including P. falciparum, the stability of repressed mRNAs requires the translational repressors DOZI and CITH. When these repressors are absent, Plasmodium zygote development and transmission to the mosquito vector is halted, as hundreds of transcripts become destabilized. However, which mRNAs are direct targets of these RNA binding proteins, and thus subject to translational repression, is unknown. Results We identify the maternal mRNA contribution to post-fertilization development of P. berghei using RNA immunoprecipitation and microarray analysis. We find that 731 mRNAs, approximately 50% of the transcriptome, are associated with DOZI and CITH, allowing zygote development to proceed in the absence of RNA polymerase II transcription. Using GFP-tagging, we validate the repression phenotype of selected genes and identify mRNAs relying on the 5′ untranslated region for translational control. Gene deletion reveals a novel protein located in the ookinete crystalloid with an essential function for sporozoite development. Conclusions Our study details for the first time the P. berghei maternal repressome. This mRNA population provides the developing ookinete with coding potential for key molecules required for life-cycle progression, and that are likely to be critical for the transmission of the malaria parasite from the rodent and the human host to the mosquito vector.

  17. [When doors slam, fingers jam!].

    Science.gov (United States)

    Claudet, I; Toubal, K; Carnet, C; Rekhroukh, H; Zelmat, B; Debuisson, C; Cahuzac, J-P

    2007-08-01

    Epidemiological analysis in a universitary paediatric emergency unit of children admitted after accidental injuries resulting from fingers crushed in a door. Prospective, descriptive cohort study from September 6th, 2004 to July 1st, 2005 included all children admitted for finger injuries crushed in a non-automatic door. included accidents due to automatic doors, toy's or refrigerator doors, families who refused to participate to the study or families who had left the waiting area before medical examination. Collected data were patient and family characteristics, accident characteristics and its management. Three hundred and forty children affected by 427 digital lesions were included. The mean age was 5.5+/-3.8 years (range 4 months - 15.5 years). Male/female ratio was equal to 1.2: 1. Fifty-eight percent of patients belonged to families composed of 3 or more siblings. Ninety-three per cent of families came to hospital within the first 2 hours after the accident (mean delay 99+/-162 min, median range 54 minutes). Location of the accident was: domestic (62%, at home (64%)), at school (17%). Locations within the home were: the bedroom (33%), bathroom and toilets (21%). An adult was present in 75% of cases and responsible for the trauma in 25% of accidents, another child in 44%. The finger or fingers were trapped on the hinge side in 57% of patients. No specific safeguard devices were used by 94% of families. Among victims, 20% had several crushed digits; left and right hand were injured with an equal frequency. The commonest involved digits were: the middle finger (29%), the ring finger (23%). The nail plate was damaged in 60% of digital lesions, associated with a wound (50%), a distal phalanx fracture (P3) (12%). Six children had a partial or complete amputation of P3, 2 children a lesion of the extensor tendon, 1 child had a rupture of the external lateral ligament. Three percent of children required an admission to the paediatric orthopaedic surgery unit. Post

  18. Polycomb group protein-mediated repression of transcription

    DEFF Research Database (Denmark)

    Morey, Lluís; Helin, Kristian

    2010-01-01

    The polycomb group (PcG) proteins are essential for the normal development of multicellular organisms. They form multi-protein complexes that work as transcriptional repressors of several thousand genes controlling differentiation pathways during development. How the PcG proteins work as transcri...

  19. [Symmetrical lividity of the fingers].

    Science.gov (United States)

    Kocsard, E; Kossard, S

    1988-07-01

    Symmetric lividity of the soles of the feet was first reported in two children in 1925 by Pernet. The characteristic manifestation of this dermatosis consisted in hyperkeratosis and hyperhidrosis with livid discoloration of the pressure areas of the soles. Later the same name was applied to a similar dermatosis in which the hyperkeratotic and hyperhidrotic patches of skin on the soles had a whitish grey discoloration and the livid color, if present at all, was seen only over the marginal areas not affected by the keratosis. Similar livid keratoses affecting the palmar sides of the fingers have been seen only occasionally. The 17-year-old girl presented in this paper had a 11-year history of emotional hyperhidrosis and is a rare illustration of symmetrical lividity in its original form, localized to the fingers only.

  20. Transcriptional activity and nuclear localization of Cabut, the Drosophila ortholog of vertebrate TGF-β-inducible early-response gene (TIEG proteins.

    Directory of Open Access Journals (Sweden)

    Yaiza Belacortu

    Full Text Available BACKGROUND: Cabut (Cbt is a C(2H(2-class zinc finger transcription factor involved in embryonic dorsal closure, epithelial regeneration and other developmental processes in Drosophila melanogaster. Cbt orthologs have been identified in other Drosophila species and insects as well as in vertebrates. Indeed, Cbt is the Drosophila ortholog of the group of vertebrate proteins encoded by the TGF-ß-inducible early-response genes (TIEGs, which belong to Sp1-like/Krüppel-like family of transcription factors. Several functional domains involved in transcriptional control and subcellular localization have been identified in the vertebrate TIEGs. However, little is known of whether these domains and functions are also conserved in the Cbt protein. METHODOLOGY/PRINCIPAL FINDINGS: To determine the transcriptional regulatory activity of the Drosophila Cbt protein, we performed Gal4-based luciferase assays in S2 cells and showed that Cbt is a transcriptional repressor and able to regulate its own expression. Truncated forms of Cbt were then generated to identify its functional domains. This analysis revealed a sequence similar to the mSin3A-interacting repressor domain found in vertebrate TIEGs, although located in a different part of the Cbt protein. Using β-Galactosidase and eGFP fusion proteins, we also showed that Cbt contains the bipartite nuclear localization signal (NLS previously identified in TIEG proteins, although it is non-functional in insect cells. Instead, a monopartite NLS, located at the amino terminus of the protein and conserved across insects, is functional in Drosophila S2 and Spodoptera exigua Sec301 cells. Last but not least, genetic interaction and immunohistochemical assays suggested that Cbt nuclear import is mediated by Importin-α2. CONCLUSIONS/SIGNIFICANCE: Our results constitute the first characterization of the molecular mechanisms of Cbt-mediated transcriptional control as well as of Cbt nuclear import, and demonstrate the

  1. Zinc finger protein 521 overexpression increased transcript levels of ...

    Indian Academy of Sciences (India)

    2016-02-12

    Feb 12, 2016 ... Dulbecco's modified Eagle medium/Ham's-Nutrient Mixture F-12; EB, embryoid body; EBF1, early B-cell factor 1; FITC, fluorescein isothiocyanate;. Fndc5, firbonectin type III domain containing 5; Gapdh, glyceraldehyde-3-phosphate dehydrogenase; LIF, leukemia inhibitory factor; mESCs, mouse embryonic ...

  2. Zinc finger protein 521 overexpression increased transcript levels of ...

    Indian Academy of Sciences (India)

    ... Iran; Department of Biology, School of Sciences, University of Isfahan, Isfahan, Iran; Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran; Department of Developmental Biology, University of Science and Culture, ...

  3. Radiation-induced tetramer-to-dimer transition of Escherichia coli lactose repressor

    International Nuclear Information System (INIS)

    Goffinont, S.; Davidkova, M.; Spotheim-Maurizot, M.

    2009-01-01

    The wild type lactose repressor of Escherichia coli is a tetrameric protein formed by two identical dimers. They are associated via a C-terminal 4-helix bundle (called tetramerization domain) whose stability is ensured by the interaction of leucine zipper motifs. Upon in vitro γ-irradiation the repressor losses its ability to bind the operator DNA sequence due to damage of its DNA-binding domains. Using an engineered dimeric repressor for comparison, we show here that irradiation induces also the change of repressor oligomerisation state from tetramer to dimer. The splitting of the tetramer into dimers can result from the oxidation of the leucine residues of the tetramerization domain.

  4. miR-200b mediates post-transcriptional repression of ZFHX1B

    DEFF Research Database (Denmark)

    Christoffersen, Nanna Rønbjerg; Silahtaroglu, Asli; Ørom, Ulf Lupo Andersson

    2007-01-01

    MicroRNAs have important functions during animal development and homeostasis through post-transcriptional regulation of their cognate mRNA targets. ZFHX1B is a transcriptional repressor involved in the TGFbeta signaling pathway and in processes of epithelial to mesenchymal transition via regulation...

  5. Transcriptional activation by the thyroid hormone receptor through ligand-dependent receptor recruitment and chromatin remodelling

    DEFF Research Database (Denmark)

    Grøntved, Lars; Waterfall, Joshua J; Kim, Dong Wook

    2015-01-01

    A bimodal switch model is widely used to describe transcriptional regulation by the thyroid hormone receptor (TR). In this model, the unliganded TR forms stable, chromatin-bound complexes with transcriptional co-repressors to repress transcription. Binding of hormone dissociates co-repressors and......A bimodal switch model is widely used to describe transcriptional regulation by the thyroid hormone receptor (TR). In this model, the unliganded TR forms stable, chromatin-bound complexes with transcriptional co-repressors to repress transcription. Binding of hormone dissociates co......-repressors and facilitates recruitment of co-activators to activate transcription. Here we show that in addition to hormone-independent TR occupancy, ChIP-seq against endogenous TR in mouse liver tissue demonstrates considerable hormone-induced TR recruitment to chromatin associated with chromatin remodelling and activated...... gene transcription. Genome-wide footprinting analysis using DNase-seq provides little evidence for TR footprints both in the absence and presence of hormone, suggesting that unliganded TR engagement with repressive complexes on chromatin is, similar to activating receptor complexes, a highly dynamic...

  6. The transcription factor Slug represses E-cadherin expression and induces epithelial to mesenchymal transitions

    DEFF Research Database (Denmark)

    Bolós, Victoria; Peinado, Hector; Pérez-Moreno, Mirna A

    2003-01-01

    Transcriptional repression mechanisms have emerged as one of the crucial processes for the downregulation of E-cadherin expression during development and tumour progression. Recently, several E-cadherin transcriptional repressors have been characterized (Snail, E12/E47, ZEB-1 and SIP-1) and shown...

  7. Conscious and Unconscious Emotions in Alexithymics and Repressors

    Directory of Open Access Journals (Sweden)

    Tsvetelina Slavchova Hadzhieva

    2017-04-01

    Full Text Available In this article, the nature, evolution and characteristics of conscious and unconscious emotions which determine the internal regulation of behavior are traced. Definitions of the nature of emotions and feelings of other authors are presented, and studies which reflect the cognitive relationship of emotional processes are cited. A classification of two different personality types has been considered (alexithymic and repressor, who differently express their emotions, because of their cognitive peculiarities. The main idea of ​​the article is based on tracing the specifics of emotional expression and intensity.

  8. [Cloning and structure analysis of zinc finger protein gene in Populus euphratica Oliv].

    Science.gov (United States)

    Wang, Jun-Ying; Yin, Wei-Lun; Xia, Xin-Li

    2005-03-01

    Zinc finger proteins belong to a family of nuclear transcription factors which function is to regulate gene expression in both prokaryotic and eukaryotic cells. A pair of primers was designed after analyzing the conservation of salt-tolerant zinc protein Alfin-1 in such diverse plants as alfalfa and Arabidopsis. The zinc finger protein gene is isolated from total RNA with RT-PCR in aquaculture leaves of Populus euphratica . Its full cDNA length is 924bp. Analysis of its amino acid sequence showed it has a typical Cys(2)/His(2) zinc finger structure and a G-rich promoter binding site GTGGGG, starting from position 556. Since transcrptional factors which have the same function show conservation in structure and amino acid sequence of DNA binding region, the structure analysis in this paper indicates the cloned zinc finger protein gene may have functional correlation to Alfin-1.

  9. BACH transcription factors in innate and adaptive immunity.

    Science.gov (United States)

    Igarashi, Kazuhiko; Kurosaki, Tomohiro; Roychoudhuri, Rahul

    2017-07-01

    BTB and CNC homology (BACH) proteins are transcriptional repressors of the basic region leucine zipper (bZIP) transcription factor family. Recent studies indicate widespread roles of BACH proteins in controlling the development and function of the innate and adaptive immune systems, including the differentiation of effector and memory cells of the B and T cell lineages, CD4 + regulatory T cells and macrophages. Here, we emphasize similarities at a molecular level in the cell-type-specific activities of BACH factors, proposing that competitive interactions of BACH proteins with transcriptional activators of the bZIP family form a common mechanistic theme underlying their diverse actions. The findings contribute to a general understanding of how transcriptional repressors shape lineage commitment and cell-type-specific functions through repression of alternative lineage programmes.

  10. Zinc finger protein 521 antagonizes early B-cell factor 1 and modulates the B-lymphoid differentiation of primary hematopoietic progenitors

    NARCIS (Netherlands)

    Mega, Tiziana; Lupia, Michela; Amodio, Nicola; Horton, Sarah J.; Mesuraca, Maria; Pelaggi, Daniela; Agosti, Valter; Grieco, Michele; Chiarella, Emanuela; Spina, Raffaella; Moore, Malcolm A. S.; Schuringa, Jan Jacob; Bond, Heather M.; Morrone, Giovanni

    2011-01-01

    Zinc finger protein 521 (EHZF/ZNF521) is a multi-functional transcription co-factor containing 30 zinc fingers and an N-terminal motif that binds to the nucleosome remodelling and histone deacetylase (NuRD) complex. ZNF521 is believed to be a relevant player in the regulation of the homeostasis of

  11. The role of C2H2 zinc finger proteins in plant responses to abiotic stresses.

    Science.gov (United States)

    Wang, Ke; Ding, Yanfei; Cai, Chong; Chen, Zhixiang; Zhu, Cheng

    2018-03-23

    Abiotic stresses are important factors affecting plant growth and development and limiting agricultural production worldwide. Plants have evolved complex regulatory mechanisms to respond and adapt to constantly changing environmental conditions. C2H2 zinc finger proteins form a relatively large family of transcriptional regulators in plants. Recent studies have revealed that C2H2 zinc finger proteins function as key transcriptional regulators in plant responses to a wide spectrum of stress conditions, including extreme temperatures, salinity, drought, oxidative stress, excessive light and silique shattering. Here, we summarize recent functional analysis on C2H2 zinc finger proteins in plant responses to abiotic stresses and discuss their roles as part of a large regulatory network in the perception and responses by plants to different environmental stimuli. This article is protected by copyright. All rights reserved.

  12. NMR structure of the single QALGGH zinc finger domain from the Arabidopsis thaliana SUPERMAN protein.

    Science.gov (United States)

    Isernia, Carla; Bucci, Enrico; Leone, Marilisa; Zaccaro, Laura; Di Lello, Paola; Digilio, Giuseppe; Esposito, Sabrina; Saviano, Michele; Di Blasio, Benedetto; Pedone, Carlo; Pedone, Paolo V; Fattorusso, Roberto

    2003-03-03

    Zinc finger domains of the classical type represent the most abundant DNA binding domains in eukaryotic transcription factors. Plant proteins contain from one to four zinc finger domains, which are characterized by high conservation of the sequence QALGGH, shown to be critical for DNA-binding activity. The Arabidopsis thaliana SUPERMAN protein, which contains a single QALGGH zinc finger, is necessary for proper spatial development of reproductive floral tissues and has been shown to specifically bind to DNA. Here, we report the synthesis and UV and NMR spectroscopic structural characterization of a 37 amino acid SUPERMAN region complexed to a Zn(2+) ion (Zn-SUP37) and present the first high-resolution structure of a classical zinc finger domain from a plant protein. The NMR structure of the SUPERMAN zinc finger domain consists of a very well-defined betabetaalpha motif, typical of all other Cys(2)-His(2) zinc fingers structurally characterized. As a consequence, the highly conserved QALGGH sequence is located at the N terminus of the alpha helix. This region of the domain of animal zinc finger proteins consists of hypervariable residues that are responsible for recognizing the DNA bases. Therefore, we propose a peculiar DNA recognition code for the QALGGH zinc finger domain that includes all or some of the amino acid residues at positions -1, 2, and 3 (numbered relative to the N terminus of the helix) and possibly others at the C-terminal end of the recognition helix. This study further confirms that the zinc finger domain, though very simple, is an extremely versatile DNA binding motif.

  13. Current status of ultrasonography of the finger

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seun Ah; Kim, Baek Hyun [Dept. of Radiology, Korea University Ansan Hospital, Korea University College of Medicine, Ansan (Korea, Republic of); Kim, Seon Jeong [Dept. of Radiology, Myongji Hospital, Seonam University College of Medicine, Goyang (Korea, Republic of); Kim, Ji Na [Dept. of Radiology, Chungnam National University Hospital, Chungnam National University School of Medicine, Daejeon (Korea, Republic of); Park, Sun Young [Dept. of Radiology, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang (Korea, Republic of); Choi, Kyung Hee [Incheon Baek Hospital, Incheon (Korea, Republic of)

    2016-03-15

    The recent development of advanced high-resolution transducers has enabled the fast, easy, and dynamic ultrasonographic evaluation of small, superficial structures such as the finger. In order to best exploit these advances, it is important to understand the normal anatomy and the basic pathologies of the finger, as exemplified by the following conditions involving the dorsal, volar, and lateral sections of the finger: sagittal band injuries, mallet finger, and Boutonnière deformity (dorsal aspect); flexor tendon tears, trigger finger, and volar plate injuries (volar aspect); gamekeeper’s thumb (Stener lesions) and other collateral ligament tears (lateral aspect); and other lesions. This review provides a basis for understanding the ultrasonography of the finger and will therefore be useful for radiologists.

  14. Prosthetic rehabilitation of an amputated finger

    Directory of Open Access Journals (Sweden)

    Meenu Garg

    2016-01-01

    Full Text Available Amputation of finger causes devastating physical, psychosocial, and economic damage to an individual. The concealment of an amputated part with the help of prosthesis can shield an amputee from social stigma. Prosthesis for such patient must be comfortable to wear lightweight, durable, cosmetically pleasing easy to put on and remove. The restoration of finger amputations depends on the amount of tissue involved, the involvement of bone, the angles and levels of amputation, and the involvement of other fingers. The microsurgical reimplantation helps to save many severely injured and traumatically amputed finger. The prosthetic rehabilitation of an amputated finger is considered when microvascular reconstruction is not possible, unavailable, unsuccessful, or unaffordable. Most accepted material is silicones because of their better esthetics, ease of manipulation, and availability. This paper presents prosthetic rehabilitation of index finger of the right hand with custom made silicon prosthesis.

  15. In the finger it lingers

    Directory of Open Access Journals (Sweden)

    Irfan Mohamad

    2017-08-01

    Full Text Available A previously healthy 80-year-old woman presented with a history of a thorn prick injury over the distal phalange of her left finger obtained while gardening two months ago. She claimed to have a non-healing cut with a nodular lesion, which progressively increased in size, extending upwards towards the region of her left arm. There was no fever or palpable lymph nodes in the axillary region. She had been prescribed antibiotics from the local hospital but her condition did not improve.

  16. The clockwork orange Drosophila protein functions as both an activator and a repressor of clock gene expression.

    Science.gov (United States)

    Richier, Benjamin; Michard-Vanhée, Christine; Lamouroux, Annie; Papin, Christian; Rouyer, François

    2008-04-01

    The Drosophila clock relies on transcriptional feedback loops that generate daily oscillations of the clock gene expression at mRNA and protein levels. In the evening, the CLOCK (CLK) and CYCLE (CYC) basic helix-loop-helix (bHLH) PAS-domain transcription factors activate the expression of the period (per) and timeless (tim) genes. Posttranslational modifications delay the accumulation of PER and TIM, which inhibit CLK/CYC activity in the late night. We show here that a null mutant of the clockwork orange (cwo) gene encoding a bHLH orange-domain putative transcription factor displays long-period activity rhythms. cwo loss of function increases cwo mRNA levels but reduces mRNA peak levels of the 4 described CLK/CYC targets, inducing an almost complete loss of their cycling. In addition, the absence of CWO induces alterations of PER and CLK phosphorylation cycles. Our results indicate that, in vivo, CWO modulates clock gene expression through both repressor and activator transcriptional functions.

  17. Recognition of AT-Rich DNA Binding Sites by the MogR Repressor

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Aimee; Higgins, Darren E.; Panne, Daniel; (Harvard-Med); (EMBL)

    2009-07-22

    The MogR transcriptional repressor of the intracellular pathogen Listeria monocytogenes recognizes AT-rich binding sites in promoters of flagellar genes to downregulate flagellar gene expression during infection. We describe here the 1.8 A resolution crystal structure of MogR bound to the recognition sequence 5' ATTTTTTAAAAAAAT 3' present within the flaA promoter region. Our structure shows that MogR binds as a dimer. Each half-site is recognized in the major groove by a helix-turn-helix motif and in the minor groove by a loop from the symmetry-related molecule, resulting in a 'crossover' binding mode. This oversampling through minor groove interactions is important for specificity. The MogR binding site has structural features of A-tract DNA and is bent by approximately 52 degrees away from the dimer. The structure explains how MogR achieves binding specificity in the AT-rich genome of L. monocytogenes and explains the evolutionary conservation of A-tract sequence elements within promoter regions of MogR-regulated flagellar genes.

  18. Concentration and length dependence of DNA looping in transcriptional regulation.

    Directory of Open Access Journals (Sweden)

    Lin Han

    2009-05-01

    Full Text Available In many cases, transcriptional regulation involves the binding of transcription factors at sites on the DNA that are not immediately adjacent to the promoter of interest. This action at a distance is often mediated by the formation of DNA loops: Binding at two or more sites on the DNA results in the formation of a loop, which can bring the transcription factor into the immediate neighborhood of the relevant promoter. These processes are important in settings ranging from the historic bacterial examples (bacterial metabolism and the lytic-lysogeny decision in bacteriophage, to the modern concept of gene regulation to regulatory processes central to pattern formation during development of multicellular organisms. Though there have been a variety of insights into the combinatorial aspects of transcriptional control, the mechanism of DNA looping as an agent of combinatorial control in both prokaryotes and eukaryotes remains unclear. We use single-molecule techniques to dissect DNA looping in the lac operon. In particular, we measure the propensity for DNA looping by the Lac repressor as a function of the concentration of repressor protein and as a function of the distance between repressor binding sites. As with earlier single-molecule studies, we find (at least two distinct looped states and demonstrate that the presence of these two states depends both upon the concentration of repressor protein and the distance between the two repressor binding sites. We find that loops form even at interoperator spacings considerably shorter than the DNA persistence length, without the intervention of any other proteins to prebend the DNA. The concentration measurements also permit us to use a simple statistical mechanical model of DNA loop formation to determine the free energy of DNA looping, or equivalently, the for looping.

  19. Characterization of Transcriptional Repressor Gene MSX1 Variations for Possible Associations with Congenital Heart Diseases.

    Directory of Open Access Journals (Sweden)

    Fei-Feng Li

    Full Text Available The human heart consists of several cell types with distinct lineage origins. Interactions between these cardiac progenitors are very important for heart formation. The muscle segment homeobox gene family plays a key role in the cell morphogenesis and growth, controlled cellular proliferation, differentiation, and apoptosis, but the relationships between the genetic abnormalities and CHD phenotypes still remain largely unknown. The aim of this work was to evaluate variations in MSX1 and MSX2 for their possible associations with CHD.We sequenced the MSX1 and MSX2 genes for 300 Chinese Han CHD patients and 400 normal controls and identified the variations. The statistical analyses were conducted using Chi-Square Tests as implemented in SPSS (version 19.0. The Hardy-Weinberg equilibrium test of the population was carried out using the online software OEGE.Six variations rs4647952, rs2048152, rs4242182, rs61739543, rs111542301 and rs3087539 were identified in the MSX2 gene, but the genetic heterozygosity of those SNPs was very low. In contrast, the genetic heterozygosity of two variations rs3821949 near the 5'UTR and rs12532 within 3'UTR of the MSX1 gene was considerably high. Statistical analyses showed that rs3821949 and rs12532 were associated with the risk of CHD (specifically VSD.The SNPs rs3821949 and rs12532 in the MSX1 gene were associated with CHD in Chinese Han populations.

  20. Synergy of feedback mechanisms in gene regulation systems with promoter and repressor transcription factors

    Czech Academy of Sciences Publication Activity Database

    Šrobár, Fedor

    2008-01-01

    Roč. 6, č. 1 (2008), s. 38-44 ISSN 1895-1082 Institutional research plan: CEZ:AV0Z20670512 Keywords : biophysics * feedback * signal flow graphs Subject RIV: BO - Biophysics Impact factor: 0.448, year: 2008

  1. Transcriptional Repressor PtvR Regulates Phenotypic Tolerance to Vancomycin in Streptococcus pneumoniae

    NARCIS (Netherlands)

    Liu, Xue; Li, Jing-Wen; Feng, Zhixing; Luo, Youfu; Veening, Jan-Willem; Zhang, Jing-Ren

    Reversible or phenotypic tolerance to antibiotics within microbial populations has been implicated in treatment failure of chronic infections and development of persister cells. However, the molecular mechanisms regulating phenotypic drug tolerance are largely unknown. In this study, we identified a

  2. Activating PER repressor through a DBT-directed phosphorylation switch.

    Directory of Open Access Journals (Sweden)

    Saul Kivimäe

    2008-07-01

    Full Text Available Protein phosphorylation plays an essential role in the generation of circadian rhythms, regulating the stability, activity, and subcellular localization of certain proteins that constitute the biological clock. This study examines the role of the protein kinase Doubletime (DBT, a Drosophila ortholog of human casein kinase I (CKIepsilon/delta. An enzymatically active DBT protein is shown to directly phosphorylate the Drosophila clock protein Period (PER. DBT-dependent phosphorylation sites are identified within PER, and their functional significance is assessed in a cultured cell system and in vivo. The per(S mutation, which is associated with short-period (19-h circadian rhythms, alters a key phosphorylation target within PER. Inspection of this and neighboring sequence variants indicates that several DBT-directed phosphorylations regulate PER activity in an integrated fashion: Alternative phosphorylations of two adjoining sequence motifs appear to be associated with switch-like changes in PER stability and repressor function.

  3. Structural basis for oligomerization of auxin transcriptional regulators.

    Science.gov (United States)

    Nanao, Max H; Vinos-Poyo, Thomas; Brunoud, Géraldine; Thévenon, Emmanuel; Mazzoleni, Meryl; Mast, David; Lainé, Stéphanie; Wang, Shucai; Hagen, Gretchen; Li, Hanbing; Guilfoyle, Thomas J; Parcy, François; Vernoux, Teva; Dumas, Renaud

    2014-04-07

    The plant hormone auxin is a key morphogenetic regulator acting from embryogenesis onwards. Transcriptional events in response to auxin are mediated by the auxin response factor (ARF) transcription factors and the Aux/IAA (IAA) transcriptional repressors. At low auxin concentrations, IAA repressors associate with ARF proteins and recruit corepressors that prevent auxin-induced gene expression. At higher auxin concentrations, IAAs are degraded and ARFs become free to regulate auxin-responsive genes. The interaction between ARFs and IAAs is thus central to auxin signalling and occurs through the highly conserved domain III/IV present in both types of proteins. Here, we report the crystal structure of ARF5 domain III/IV and reveal the molecular determinants of ARF-IAA interactions. We further provide evidence that ARFs have the potential to oligomerize, a property that could be important for gene regulation in response to auxin.

  4. TcNPR3 from Theobroma cacao functions as a repressor of the pathogen defense response.

    Science.gov (United States)

    Shi, Zi; Zhang, Yufan; Maximova, Siela N; Guiltinan, Mark J

    2013-12-06

    Arabidopsis thaliana (Arabidopsis) NON-EXPRESSOR OF PR1 (NPR1) is a transcription coactivator that plays a central role in regulating the transcriptional response to plant pathogens. Developing flowers of homozygous npr3 mutants are dramatically more resistant to infection by the pathogenic bacterium Pseudomonas syringae, suggesting a role of NPR3 as a repressor of NPR1-mediated defense response with a novel role in flower development. We report here the characterization of a putative NPR3 gene from the tropical tree species Theobroma cacao (TcNPR3). Like in Arabidopsis, TcNPR3 was constitutively expressed across a wide range of tissue types and developmental stages but with some differences in relative levels compared to Arabidopsis. To test the function of TcNPR3, we performed transgenic complementation analysis by introducing a constitutively expressing putative TcNPR3 transgene into an Arabidopsis npr3 mutant. TcNPR3 expressing Arabidopsis plants were partially restored to the WT pathogen phenotype (immature flowers susceptible to bacterial infection). To test TcNPR3 function directly in cacao tissues, a synthetic microRNA targeting TcNPR3 mRNA was transiently expressed in cacao leaves using an Agrobacterium-infiltration method. TcNPR3 knock down leaf tissues were dramatically more resistance to infection with Phytophthora capsici in a leaf bioassay, showing smaller lesion sizes and reduced pathogen replication. We conclude that TcNPR3 functions similar to the Arabidopsis NPR3 gene in the regulation of the cacao defense response. Since TcNPR3 did not show a perfect complementation of the Arabidopsis NPR3 mutation, the possibility remains that other functions of TcNPR3 remain to be found. This novel knowledge can contribute to the breeding of resistant cacao varieties against pathogens through molecular markers based approaches or biotechnological strategies.

  5. Haematopoietic malignancies caused by dysregulation of a chromatin-binding PHD finger

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Gang G.; Song, Jikui; Wang, Zhanxin; Dormann, Holger L.; Casadio, Fabio; Li, Haitao; Luo, Jun-Li; Patel, Dinshaw J.; Allis, C. David; (MSKCC); (Scripps); (Rockefeller)

    2009-07-21

    Histone H3 lysine4 methylation (H3K4me) has been proposed as a critical component in regulating gene expression, epigenetic states, and cellular identities. The biological meaning of H3K4me is interpreted by conserved modules including plant homeodomain (PHD) fingers that recognize varied H3K4me states. The dysregulation of PHD fingers has been implicated in several human diseases, including cancers and immune or neurological disorders. Here we report that fusing an H3K4-trimethylation (H3K4me3)-binding PHD finger, such as the carboxy-terminal PHD finger of PHF23 or JARID1A (also known as KDM5A or RBBP2), to a common fusion partner nucleoporin-98 (NUP98) as identified in human leukaemias, generated potent oncoproteins that arrested haematopoietic differentiation and induced acute myeloid leukaemia in murine models. In these processes, a PHD finger that specifically recognizes H3K4me3/2 marks was essential for leukaemogenesis. Mutations in PHD fingers that abrogated H3K4me3 binding also abolished leukaemic transformation. NUP98-PHD fusion prevented the differentiation-associated removal of H3K4me3 at many loci encoding lineage-specific transcription factors (Hox(s), Gata3, Meis1, Eya1 and Pbx1), and enforced their active gene transcription in murine haematopoietic stem/progenitor cells. Mechanistically, NUP98-PHD fusions act as 'chromatin boundary factors', dominating over polycomb-mediated gene silencing to 'lock' developmentally critical loci into an active chromatin state (H3K4me3 with induced histone acetylation), a state that defined leukaemia stem cells. Collectively, our studies represent, to our knowledge, the first report that deregulation of the PHD finger, an 'effector' of specific histone modification, perturbs the epigenetic dynamics on developmentally critical loci, catastrophizes cellular fate decision-making, and even causes oncogenesis during mammalian development.

  6. A phospho-sugar binding domain homologous to NagB enzymes regulates the activity of the central glycolytic genes repressor.

    Science.gov (United States)

    Doan, Thierry; Martin, Laetitia; Zorrilla, Silvia; Chaix, Denis; Aymerich, Stéphane; Labesse, Gilles; Declerck, Nathalie

    2008-06-01

    CggR belongs to the SorC family of bacterial transcriptional regulators which control the expression of genes and operons involved in carbohydrate catabolism. CggR was first identified in Bacillus subtilis where it represses the gapA operon encoding the five enzymes that catalyze the central part of glycolysis. Here we present a structure/function study demonstrating that the C-terminal region of CggR regulates the DNA binding activity of this repressor in response to binding of a phosphorylated sugar. Molecular modeling of CggR revealed a winged-helix DNA-binding motif followed by a C-terminal domain presenting weak but significant homology with glucosamine-6-phosphate deaminases from the NagB family. In silico ligand screening suggested that the CggR C-terminal domain would bind preferentially bi-phosphorylated compounds, in agreement with previous studies that proposed fructuose-1,6-biphosphate (FBP) as the inducer metabolite. In vitro, FBP was the only sugar compound capable of interfering with CggR cooperative binding to DNA. FBP was also found to protect CggR against trypsin degradation at two arginine residues predicted to reside in a mobile loop forming the active site lid of the NagB enzymes. Replacement of residues predicted to interact with FBP led to mutant CggR with altered repressor activity in vivo but retaining their structural integrity and DNA binding activity in vitro. Interestingly, some of the mutant repressors responded with different specificity towards mono- and di-phospho-fructosides. Based on these results, we propose that the activity of the CggR-like repressors is controlled by a phospho-sugar binding (PSB) domain presenting structural and functional homology with NagB enzymes. (c) 2008 Wiley-Liss, Inc.

  7. bHLH003, bHLH013 and bHLH017 are new targets of JAZ repressors negatively regulating JA responses.

    Directory of Open Access Journals (Sweden)

    Sandra Fonseca

    Full Text Available Cell reprogramming in response to jasmonates requires a tight control of transcription that is achieved by the activity of JA-related transcription factors (TFs. Among them, MYC2, MYC3 and MYC4 have been described as activators of JA responses. Here we characterized the function of bHLH003, bHLH013 and bHLH017 that conform a phylogenetic clade closely related to MYC2, MYC3 and MYC4. We found that these bHLHs form homo- and heterodimers and also interact with JAZ repressors in vitro and in vivo. Phenotypic analysis of JA-regulated processes, including root and rosette growth, anthocyanin accumulation, chlorophyll loss and resistance to Pseudomonas syringae, on mutants and overexpression lines, suggested that these bHLHs are repressors of JA responses. bHLH003, bHLH013 and bHLH017 are mainly nuclear proteins and bind DNA with similar specificity to that of MYC2, MYC3 and MYC4, but lack a conserved activation domain, suggesting that repression is achieved by competition for the same cis-regulatory elements. Moreover, expression of bHLH017 is induced by JA and depends on MYC2, suggesting a negative feed-back regulation of the activity of positive JA-related TFs. Our results suggest that the competition between positive and negative TFs determines the output of JA-dependent transcriptional activation.

  8. Surgical Treatment of Trigger Finger: Open Release

    Directory of Open Access Journals (Sweden)

    Firat Ozan

    2016-01-01

    Full Text Available In this study, open A1 pulley release results were evaluated in patients with a trigger finger diagnosis. 45 patients (29 females, 16 males, mean age 50.7 ± 11.9; range (24-79, 45 trigger fingers were released via open surgical technique. On the 25 of 45 cases were involved in the right hand and 16 of them were at the thumb, 2 at index, 6 at the middle and 1 at ring finger. Similarly, at the left hand, 15 of 20 cases were at the thumb, 1 at the index finger, 2 at middle finger and 2 at ring finger. Average follow-up time was 10.2 ± 2.7 (range, 6-15 months. Comorbidities in patients were; diabetes mellitus at 6 cases (13.3%, hypertension at 11 cases (24.4%, hyperthyroidism at 2 cases (4.4%, dyslipidemia at 2 cases (4.4% and lastly 2 cases had carpal tunnel syndrome operation. The mean time between the onset of symptoms to surgery was 6.9 ± 4.8 (range, 2-24 months. Patient satisfaction was very good in 34 cases (75.4% and good in 11 (24.6% patients. The distance between the pulpa of the operated finger and the palm was normal in every case postoperatively. We have not encountered any postoperative complications. We can recommend that; A1 pulley release via open incision is an effective and reliable method in trigger finger surgery.

  9. The SUPERMAN protein is an active repressor whose carboxy-terminal repression domain is required for the development of normal flowers.

    Science.gov (United States)

    Hiratsu, Keiichiro; Ohta, Masaru; Matsui, Kyoko; Ohme-Takagi, Masaru

    2002-03-13

    SUPERMAN was identified as a putative regulator of transcription that acts in floral development, but its function remains to be clarified. We demonstrate here that SUPERMAN is an active repressor whose repression domain is located in the carboxy-terminal region. Ectopic expression of SUPERMAN that lacked the repression domain resulted in a phenotype similar to that of superman mutants, demonstrating that the repression activity of SUPERMAN is essential for the development of normal flowers. Constitutive expression of SUPERMAN resulted in a severe dwarfism but did not affect cell size, indicating that SUPERMAN might regulate genes that are involved in cell division.

  10. Regulation of gene expression by repressor localization: biochemical evidence that membrane and DNA binding by the PutA protein are mutually exclusive.

    OpenAIRE

    Muro-Pastor, A M; Ostrovsky, P; Maloy, S

    1997-01-01

    The PutA protein from Salmonella typhimurium is a bifunctional enzyme that catalyzes the oxidation of proline to glutamate, a reaction that is coupled to the transfer of electrons to the electron transport chain in the cytoplasmic membrane. The PutA protein is also a transcriptional repressor that regulates the expression of the put operon in response to the availability of proline. Despite extensive genetic and biochemical studies of the PutA protein, it was not known if the PutA protein car...

  11. Comparative Analysis of Chromatin Binding by Sex Comb on Midleg (SCM) and Other Polycomb Group Repressors at a Drosophila Hox Gene▿

    OpenAIRE

    Wang, Liangjun; Jahren, Neal; Miller, Ellen L.; Ketel, Carrie S.; Mallin, Daniel R.; Simon, Jeffrey A.

    2010-01-01

    Sex Comb on Midleg (SCM) is a transcriptional repressor in the Polycomb group (PcG), but its molecular role in PcG silencing is not known. Although SCM can interact with Polycomb repressive complex 1 (PRC1) in vitro, biochemical studies have indicated that SCM is not a core constituent of PRC1 or PRC2. Nevertheless, SCM is just as critical for Drosophila Hox gene silencing as canonical subunits of these well-characterized PcG complexes. To address functional relationships between SCM and othe...

  12. Crystal structure of the lactose operon repressor and its complexes with DNA and inducer

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, M.; Chang, G. [Johnson Research Foundation, Philadelphia, PA (United States); Horton, N.C. [Univ. of Pennsylvania, Philadelphia, PA (United States)] [and others

    1996-03-01

    The lac operon of Escherichia coli is the paradigm for gene regulation. Its key component is the lac repressor a product of the lacl gene. The three-dimensional structures of the intact lac repressor, the lac repressor bound to the gratuitous inducer isopropyl-B-D-1thiogalactoside (IPTG) and the lac repressor complexed with a 21 base pair symmetric operator DNA have been determined. These three structures show the conformation of the molecule in both the induced and the repressed states and provide a framework for understanding a wealth of biochemical and genetic information. The DNA sequence of the lac operon has three lac repressor recognition sites in stretch of 500 base pairs. The crystallographic structure of the complex with DNA suggests that the tetrameric repressor functions synergistically with catabolite gene activator protein (CAP) and participates in the quarternary formation of repression loops in which one tetrameric repressor interacts simultaneously with two sites in the genomic DNA. 76 refs., 11 figs., 1 tab.

  13. Use of twin dorsal middle phalangeal finger flaps for thumb or index finger reconstruction.

    Science.gov (United States)

    Qi, W; Chen, K J

    2013-05-01

    Amputation or degloving injuries of the thumb or index finger are highly disabling. We describe the use of twin dorsal middle finger flaps harvested from the dorsal aspects of the middle and ring fingers, and based on one palmar proper digital artery, its venae comitantes, and the dorsal branches of the palmar digital nerves of the middle and ring fingers, respectively. These flaps offer advantages when large soft tissue defects of the thumb or index finger are present. In this study, twin dorsal middle finger flaps were used in nine patients (six thumbs, three index fingers). All flaps completely survived. At the mean follow-up of 20 months, the appearance of the reconstructed thumbs or index fingers was acceptable, the length was maintained, and the mean static 2-point discrimination values were 10 mm in the palmar flap and 13 mm in the dorsal flap of the reconstructed digit. All patients were satisfied with the appearance and mobility of the donor fingers. All but one donor finger showed normal finger pulp sensibility, with a static 2-point discrimination between 3 and 6 mm.

  14. Finger wear detection for production line battery tester

    Science.gov (United States)

    Depiante, Eduardo V.

    1997-01-01

    A method for detecting wear in a battery tester probe. The method includes providing a battery tester unit having at least one tester finger, generating a tester signal using the tester fingers and battery tester unit with the signal characteristic of the electrochemical condition of the battery and the tester finger, applying wavelet transformation to the tester signal including computing a mother wavelet to produce finger wear indicator signals, analyzing the signals to create a finger wear index, comparing the wear index for the tester finger with the index for a new tester finger and generating a tester finger signal change signal to indicate achieving a threshold wear change.

  15. RNA-guided transcriptional regulation in planta via synthetic dCas9-based transcription factors

    KAUST Repository

    Piatek, Agnieszka Anna

    2014-11-14

    Targeted genomic regulation is a powerful approach to accelerate trait discovery and development in agricultural biotechnology. Bacteria and archaea use clustered regularly interspaced short palindromic repeats (CRISPRs) and CRISPR-associated (Cas) regulatory systems for adaptive molecular immunity against foreign nucleic acids introduced by invading phages and conjugative plasmids. The type II CRISPR/Cas system has been adapted for genome editing in many cell types and organisms. A recent study used the catalytically inactive Cas9 (dCas9) protein combined with guide-RNAs (gRNAs) as a DNA-targeting platform to modulate gene expression in bacterial, yeast, and human cells. Here, we modified this DNA-targeting platform for targeted transcriptional regulation in planta by developing chimeric dCas9-based transcriptional activators and repressors. To generate transcriptional activators, we fused the dCas9 C-terminus with the activation domains of EDLL and TAL effectors. To generate a transcriptional repressor, we fused the dCas9 C-terminus with the SRDX repression domain. Our data demonstrate that dCas9 fusion with the EDLL activation domain (dCas9:EDLL) and the TAL activation domain (dCas9:TAD), guided by gRNAs complementary to selected promoter elements, induce strong transcriptional activation on Bs3

  16. Repressors benefit from reappraising a threatening emotional event.

    Science.gov (United States)

    Mendolia, Marilyn

    2016-01-01

    The malleability of emotion-focused coping was investigated by manipulating the situational context so that dispositional repressors, who typically utilize an avoidant strategy when confronted with a stressor, were led to use reappraisal and then were reexposed to the stressor. A mixed design with one measured between-subjects factor (dispositional repression), two randomized between-subjects factors (performance feedback and coping strategy), and multimodal assessments across phases of the experiment was used. During a face-perception task, participants (170 female and 120 male university students) received bogus performance feedback that was inconsistent with and thus threatening to self-concept. Participants then completed a writing activity encouraging them to perceive a face-perception task as either an invalid (reappraisal) or a valid (control) assessment tool. Afterward, participants continued with the task. A repressive disposition was associated with a defense response (decreased perceived emotion to actors' expressions, increased skin conductance levels, and increased heart rates) during the face-perception task that participants perceived as threatening, but not during reexposure to the event after they had reappraised it as nonthreatening. This research provides a more detailed understanding of the dynamic nature of emotion-focused coping by exploring how the disposition-situation interaction affects self-regulation of emotion.

  17. Drosophila brakeless interacts with atrophin and is required for tailless-mediated transcriptional repression in early embryos.

    Directory of Open Access Journals (Sweden)

    Achim Haecker

    2007-06-01

    Full Text Available Complex gene expression patterns in animal development are generated by the interplay of transcriptional activators and repressors at cis-regulatory DNA modules (CRMs. How repressors work is not well understood, but often involves interactions with co-repressors. We isolated mutations in the brakeless gene in a screen for maternal factors affecting segmentation of the Drosophila embryo. Brakeless, also known as Scribbler, or Master of thickveins, is a nuclear protein of unknown function. In brakeless embryos, we noted an expanded expression pattern of the Krüppel (Kr and knirps (kni genes. We found that Tailless-mediated repression of kni expression is impaired in brakeless mutants. Tailless and Brakeless bind each other in vitro and interact genetically. Brakeless is recruited to the Kr and kni CRMs, and represses transcription when tethered to DNA. This suggests that Brakeless is a novel co-repressor. Orphan nuclear receptors of the Tailless type also interact with Atrophin co-repressors. We show that both Drosophila and human Brakeless and Atrophin interact in vitro, and propose that they act together as a co-repressor complex in many developmental contexts. We discuss the possibility that human Brakeless homologs may influence the toxicity of polyglutamine-expanded Atrophin-1, which causes the human neurodegenerative disease dentatorubral-pallidoluysian atrophy (DRPLA.

  18. Finger prosthesis: a boon to handicapped.

    Science.gov (United States)

    Gupta, Ridhima; Kumar, Lakshya; Rao, Jitendra; Singh, Kamleshwar

    2013-08-29

    This is a clinical case report of a 52-year-old male patient with four partially missing fingers of the left hand. The article describes the clinical and laboratory procedure of making prosthesis with modern silicone material. A wax pattern was fabricated using the right hand of the patient. A special type of wax was formulated to make the pattern so that it can be easily moulded and carved. Intrinsic and extrinsic staining was also performed to match the adjacent skin colour. The patient was given the finger prosthesis and was asked to use a half glove (sports) to mask the junction between the prosthesis and the normal tissue. It also provides additional retention to the artificial fingers. The patient felt his social acceptance improved after wearing the finger prosthesis.

  19. Regulation of gene expression by repressor localization: biochemical evidence that membrane and DNA binding by the PutA protein are mutually exclusive.

    Science.gov (United States)

    Muro-Pastor, A M; Ostrovsky, P; Maloy, S

    1997-04-01

    The PutA protein from Salmonella typhimurium is a bifunctional enzyme that catalyzes the oxidation of proline to glutamate, a reaction that is coupled to the transfer of electrons to the electron transport chain in the cytoplasmic membrane. The PutA protein is also a transcriptional repressor that regulates the expression of the put operon in response to the availability of proline. Despite extensive genetic and biochemical studies of the PutA protein, it was not known if the PutA protein carries out both of these two opposing functions while membrane associated or if instead it carries them out in different cellular compartments. To distinguish between these alternatives, we directly assayed the binding of purified PutA protein to DNA and membranes in vitro. The results indicate that wild-type PutA does not simultaneously associate with DNA and membranes. In addition, PutA superrepressor mutants that exhibit increased repression of the put genes show a direct correlation between decreased membrane binding and increased DNA binding. These results support a model in which the PutA protein shuttles between the membrane (where it acts as an enzyme but lacks access to DNA-binding sites) and the cytoplasm (where it binds DNA and acts as a transcriptional repressor), depending on the availability of proline.

  20. Molecular Binding Mechanism of TtgR Repressor to Antibiotics and Antimicrobials.

    Directory of Open Access Journals (Sweden)

    Ana Maria Fernandez-Escamilla

    Full Text Available A disturbing phenomenon in contemporary medicine is the prevalence of multidrug-resistant pathogenic bacteria. Efflux pumps contribute strongly to this antimicrobial drug resistance, which leads to the subsequent failure of clinical treatments. The TtgR protein of Pseudomonas putida is a HTH-type transcriptional repressor that controls expression of the TtgABC efflux pump, which is the main contributor to resistance against several antimicrobials and toxic compounds in this microbe. One of the main strategies to modulate the bacterial resistance is the rational modification of the ligand binding target site. We report the design and characterization of four mutants-TtgRS77A, TtgRE78A, TtgRN110A and TtgRH114A - at the active ligand binding site. The biophysical characterization of the mutants, in the presence and in the absence of different antimicrobials, revealed that TtgRN110A is the variant with highest thermal stability, under any of the experimental conditions tested. EMSA experiments also showed a different dissociation pattern from the operator for TtgRN110A, in the presence of several antimicrobials, making it a key residue in the TtgR protein repression mechanism of the TtgABC efflux pump. We found that TtgRE78A stability is the most affected upon effector binding. We also probe that one mutation at the C-terminal half of helix-α4, TtgRS77A, provokes a severe protein structure distortion, demonstrating the important role of this residue in the overall protein structure and on the ligand binding site. The data provide new information and deepen the understanding of the TtgR-effector binding mechanism and consequently the TtgABC efflux pump regulation mechanism in Pseudomonas putida.

  1. The flowering repressor SVP underlies a novel Arabidopsis thaliana QTL interacting with the genetic background.

    Science.gov (United States)

    Méndez-Vigo, Belén; Martínez-Zapater, José M; Alonso-Blanco, Carlos

    2013-01-01

    The timing of flowering initiation is a fundamental trait for the adaptation of annual plants to different environments. Large amounts of intraspecific quantitative variation have been described for it among natural accessions of many species, but the molecular and evolutionary mechanisms underlying this genetic variation are mainly being determined in the model plant Arabidopsis thaliana. To find novel A. thaliana flowering QTL, we developed introgression lines from the Japanese accession Fuk, which was selected based on the substantial transgression observed in an F(2) population with the reference strain Ler. Analysis of an early flowering line carrying a single Fuk introgression identified Flowering Arabidopsis QTL1 (FAQ1). We fine-mapped FAQ1 in an 11 kb genomic region containing the MADS transcription factor gene SHORT VEGETATIVE PHASE (SVP). Complementation of the early flowering phenotype of FAQ1-Fuk with a SVP-Ler transgen demonstrated that FAQ1 is SVP. We further proved by directed mutagenesis and transgenesis that a single amino acid substitution in SVP causes the loss-of-function and early flowering of Fuk allele. Analysis of a worldwide collection of accessions detected FAQ1/SVP-Fuk allele only in Asia, with the highest frequency appearing in Japan, where we could also detect a potential ancestral genotype of FAQ1/SVP-Fuk. In addition, we evaluated allelic and epistatic interactions of SVP natural alleles by analysing more than one hundred transgenic lines carrying Ler or Fuk SVP alleles in five genetic backgrounds. Quantitative analyses of these lines showed that FAQ1/SVP effects vary from large to small depending on the genetic background. These results support that the flowering repressor SVP has been recently selected in A. thaliana as a target for early flowering, and evidence the relevance of genetic interactions for the intraspecific evolution of FAQ1/SVP and flowering time.

  2. The flowering repressor SVP underlies a novel Arabidopsis thaliana QTL interacting with the genetic background.

    Directory of Open Access Journals (Sweden)

    Belén Méndez-Vigo

    Full Text Available The timing of flowering initiation is a fundamental trait for the adaptation of annual plants to different environments. Large amounts of intraspecific quantitative variation have been described for it among natural accessions of many species, but the molecular and evolutionary mechanisms underlying this genetic variation are mainly being determined in the model plant Arabidopsis thaliana. To find novel A. thaliana flowering QTL, we developed introgression lines from the Japanese accession Fuk, which was selected based on the substantial transgression observed in an F(2 population with the reference strain Ler. Analysis of an early flowering line carrying a single Fuk introgression identified Flowering Arabidopsis QTL1 (FAQ1. We fine-mapped FAQ1 in an 11 kb genomic region containing the MADS transcription factor gene SHORT VEGETATIVE PHASE (SVP. Complementation of the early flowering phenotype of FAQ1-Fuk with a SVP-Ler transgen demonstrated that FAQ1 is SVP. We further proved by directed mutagenesis and transgenesis that a single amino acid substitution in SVP causes the loss-of-function and early flowering of Fuk allele. Analysis of a worldwide collection of accessions detected FAQ1/SVP-Fuk allele only in Asia, with the highest frequency appearing in Japan, where we could also detect a potential ancestral genotype of FAQ1/SVP-Fuk. In addition, we evaluated allelic and epistatic interactions of SVP natural alleles by analysing more than one hundred transgenic lines carrying Ler or Fuk SVP alleles in five genetic backgrounds. Quantitative analyses of these lines showed that FAQ1/SVP effects vary from large to small depending on the genetic background. These results support that the flowering repressor SVP has been recently selected in A. thaliana as a target for early flowering, and evidence the relevance of genetic interactions for the intraspecific evolution of FAQ1/SVP and flowering time.

  3. JAZ repressors: Possible Involvement in Nutrients Deficiency Response in Rice and Chickpea

    Directory of Open Access Journals (Sweden)

    Ajit P. Singh

    2015-11-01

    Full Text Available Jasmonates (JA are well-known phytohormones which play important roles in plant development and defence against pathogens. Jasmonate ZIM domain (JAZ proteins are plant-specific proteins and act as transcriptional repressors of JA-responsive genes. JA regulates both biotic and abiotic stress responses in plants; however, its role in nutrient deficiency responses is very elusive. Although, JA is well-known for root growth inhibition, little is known about behaviour of JAZ genes in response to nutrient deficiencies, under which root architectural alteration is an important adaptation. Using protein sequence homology and a conserved-domains approach, here we identify ten novel JAZ genes from the recently sequenced Chickpea genome, which is one of the most nutrient efficient crops. Both rice and chickpea JAZ genes express in tissue- and stimuli-specific manners. Many of which are preferentially expressed in root. Our analysis further showed differential expression of JAZ genes under macro (NPK and micronutrients (Zn, Fe deficiency in rice and chickpea roots. While both rice and chickpea JAZ genes showed a certain level of specificity towards type of nutrient deficiency, generally majority of them showed induction under K deficiency. Generally, JAZ genes showed an induction at early stages of stress and expression declined at later stages of macro-nutrient deficiency. Our results suggest that JAZ genes might play a role in early nutrient deficiency response both in monocot and dicot roots, and information generated here can be further used for understanding the possible roles of JA in root architectural alterations for nutrient deficiency adaptations

  4. The allosteric interaction between D-galactose and the Escherichia coli galactose repressor protein.

    Science.gov (United States)

    Brown, M P; Shaikh, N; Brenowitz, M; Brand, L

    1994-04-29

    The Escherichia coli galactose repressor protein (GalR) inhibits transcription of the gal operon upon binding to two operator sites (1-7). This DNA binding activity is inhibited when D-galactose or D-fucose binds to GalR (8-14). Fluorescence spectroscopy was used to characterize the single tryptophan of GalR and to investigate the interaction between galactose and GalR. Fluorescence quenching experiments place both tryptophan residues of the GalR dimer in similar, solvent-exposed locations. Galactose is shown to enhance the intrinsic tryptophan fluorescence of GalR, the source of which is not explained by a change in decay times, but is due to an increase in the pre-exponential factor of the longest of the three fluorescence decay times. It is shown that the beta-anomer of D-galactose is the likely form that binds to GalR. An increase in pH from 6.3 to 9.5 causes the equilibrium association constant (K alpha) describing the galactose-GalR interaction to decrease 10-fold. The interaction is cooperative below pH 9.5. Over the pH range of 6.3 to 9.5, the tryptophan solvent exposure of GalR increases. Galactose binding also induces an increase in exposure. These results, and others presented in this paper, show that both pH and galactose cause global alterations in the structure of GalR.

  5. Stainless steel quadralatch finger test report

    International Nuclear Information System (INIS)

    Deichelbohrer, P.R.

    1996-01-01

    The design of the quadralatch on the universal samplers was changed in response to flammable gas operating constraints. Additional redesign of the fingers was included to facilitate manufacturability. The new design was tested to assure satisfactory performance. It was shown that the fingers can hold a sampler in place with an upward force of at least 2200 N (500 pounds) and that the mechanical remote latch unit can release the quadralatch under this condition of maximum upward force

  6. Expression, crystallization and preliminary diffraction studies of the Pseudomonas putida cytochrome P450cam operon repressor CamR

    International Nuclear Information System (INIS)

    Maenaka, Katsumi; Fukushi, Kouji; Aramaki, Hironori; Shirakihara, Yasuo

    2005-01-01

    The P. putida cytochrome P450cam operon repressor CamR has been expressed in E. coli and crystallized in space group P2 1 2 1 2. The Pseudomonas putida cam repressor (CamR) is a homodimeric protein that binds to the camO DNA operator to inhibit the transcription of the cytochrome P450cam operon camDCAB. CamR has two functional domains: a regulatory domain and a DNA-binding domain. The binding of the inducer d-camphor to the regulatory domain renders the DNA-binding domain unable to bind camO. Native CamR and its selenomethionyl derivative have been overproduced in Escherichia coli and purified. Native CamR was crystallized under the following conditions: (i) 12–14% PEG 4000, 50 mM Na PIPES, 0.1 M KCl, 1% glycerol pH 7.3 at 288 K with and without camphor and (ii) 1.6 M P i , 50 mM Na PIPES, 2 mM camphor pH 6.7 at 278 K. The selenomethionyl derivative CamR did not crystallize under either of these conditions, but did crystallize using 12.5% PEG MME 550, 25 mM Na PIPES, 2.5 mM MgCl 2 pH 7.3 at 298 K. Preliminary X-ray diffraction studies revealed the space group to be orthorhombic (P2 1 2 1 2), with unit-cell parameters a = 48.0, b = 73.3, c = 105.7 Å. Native and selenomethionyl derivative data sets were collected to 3 Å resolution at SPring-8 and the Photon Factory

  7. Finger replantation: surgical technique and indications.

    Science.gov (United States)

    Barbary, S; Dap, F; Dautel, G

    2013-12-01

    In this article, we discuss the surgical technique of finger replantation in detail, distinguishing particularities of technique in cases of thumb amputation, children fingertip replantation, ring finger avulsion, and very distal replantations. We emphasize the principles of bone shortening, the spare part concept, the special importance of nerve sutures and the use of vein graft in case of avulsion or crushing. However, even if finger replantation is now a routine procedure, a clear distinction should be made between revascularization and functional success. The indications for finger replantation are then detailed in the second part of this paper. The absolute indications for replantation are thumb, multiple fingers, transmetacarpal or hand, and any upper extremity amputation in a child whatever the level. Fingertip amputations distal to the insertion of the Flexor digitorum superficialis (FDS) are also a good indication. Other cases are more controversial because of the poor functional outcome, especially for the index finger, which is often functionally excluded. Copyright © 2013. Published by Elsevier SAS.

  8. Individual finger sensibility in carpal tunnel syndrome.

    Science.gov (United States)

    Elfar, John C; Yaseen, Zaneb; Stern, Peter J; Kiefhaber, Thomas R

    2010-11-01

    Sensibility testing plays a role in the diagnosis of carpal tunnel syndrome (CTS). No single physical examination test has proven to be of critical value in the diagnosis, especially when compared with electrodiagnostic testing (EDX). The purpose of this study was to define which digits are most affected by CTS, both subjectively and with objective sensibility testing. A prospective series of 35 patients (40 hands) with EDX-positive, isolated CTS were evaluated preoperatively using 2 objective sensibility tests: static 2-point discrimination (2PD) and abbreviated Semmes-Weinstein monofilament (SWMF) testing. Detailed surveys of subjective symptoms were also collected. Patients identified the middle finger as the most symptomatic over all others (51%). Objective 2PD results of each digit mirrored the subjective data, with higher values for the middle finger (mean 6.07 mm, (p thumb > index > small). Correlations failed between EDX, symptoms, and SWMF results or 2PD in the index finger. Positive but weak correlation (p = .002, r = .42) was found between EDX and 2PD only in the middle fingers. The middle finger is the most likely to show changes in 2PD in patients with positive EDX findings for CTS. Middle finger 2PD is best able to correlate with EDX when compared with 2PD of other digits. The SWMF testing also shows the middle digit testing as more sensitive, but this finding may be difficult to use clinically. Diagnostic I. Copyright © 2010 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  9. Chemically Induced Degradation of the Oncogenic Transcription Factor BCL6

    Directory of Open Access Journals (Sweden)

    Nina Kerres

    2017-09-01

    Full Text Available The transcription factor BCL6 is a known driver of oncogenesis in lymphoid malignancies, including diffuse large B cell lymphoma (DLBCL. Disruption of its interaction with transcriptional repressors interferes with the oncogenic effects of BCL6. We used a structure-based drug design to develop highly potent compounds that block this interaction. A subset of these inhibitors also causes rapid ubiquitylation and degradation of BCL6 in cells. These compounds display significantly stronger induction of expression of BCL6-repressed genes and anti-proliferative effects than compounds that merely inhibit co-repressor interactions. This work establishes the BTB domain as a highly druggable structure, paving the way for the use of other members of this protein family as drug targets. The magnitude of effects elicited by this class of BCL6-degrading compounds exceeds that of our equipotent non-degrading inhibitors, suggesting opportunities for the development of BCL6-based lymphoma therapeutics.

  10. Solution structure and DNA binding of the zinc-finger domain from DNA ligase IIIalpha.

    Science.gov (United States)

    Kulczyk, Arkadiusz W; Yang, Ji-Chun; Neuhaus, David

    2004-08-13

    DNA ligase IIIalpha carries out the final ligation step in the base excision repair (BER) and single strand break repair (SSBR) mechanisms of DNA repair. The enzyme recognises single-strand nicks and other damage features in double-stranded DNA, both through the catalytic domain and an N-terminal domain containing a single zinc finger. The latter is homologous to other zinc fingers that recognise damaged DNA, two in the N terminus of poly(adenosine-ribose)polymerase and three in the N terminus of the Arabidopsis thaliana nick-sensing DNA 3'-phosphoesterase. Here, we present the solution structure of the zinc-finger domain of human DNA ligase IIIalpha, the first structure of a finger from this group. It is related to that of the erythroid transcription factor GATA-1, but has an additional N-terminal beta-strand and C-terminal alpha-helix. Chemical shift mapping using a DNA ligand containing a single-stranded break showed that the DNA-binding surface of the DNA-ligase IIIalpha zinc finger is substantially different from that of GATA-1, consistent with the fact that the two proteins recognise very different features in the DNA. Likely implications for DNA binding are discussed.

  11. Finger multibiometric cryptosystems: fusion strategy and template security

    Science.gov (United States)

    Peng, Jialiang; Li, Qiong; Abd El-Latif, Ahmed A.; Niu, Xiamu

    2014-03-01

    We address two critical issues in the design of a finger multibiometric system, i.e., fusion strategy and template security. First, three fusion strategies (feature-level, score-level, and decision-level fusions) with the corresponding template protection technique are proposed as the finger multibiometric cryptosystems to protect multiple finger biometric templates of fingerprint, finger vein, finger knuckle print, and finger shape modalities. Second, we theoretically analyze different fusion strategies for finger multibiometric cryptosystems with respect to their impact on security and recognition accuracy. Finally, the performance of finger multibiometric cryptosystems at different fusion levels is investigated on a merged finger multimodal biometric database. The comparative results suggest that the proposed finger multibiometric cryptosystem at feature-level fusion outperforms other approaches in terms of verification performance and template security.

  12. ErbB2-Driven Breast Cancer Cell Invasion Depends on a Complex Signaling Network Activating Myeloid Zinc Finger-1-Dependent Cathepsin B Expression

    DEFF Research Database (Denmark)

    Rafn, Bo; Nielsen, Christian Thomas Friberg; Andersen, Sofie Hagel

    2012-01-01

    signaling network activates the transcription of cathepsin B gene (CTSB) via myeloid zinc finger-1 transcription factor that binds to an ErbB2-responsive enhancer element in the first intron of CTSB. This work provides a model system for ErbB2-induced breast cancer cell invasiveness, reveals a signaling...

  13. Characterization of transcriptional regulatory domains of ankyrin repeat cofactor-1

    International Nuclear Information System (INIS)

    Zhang, Aihua; Li, Chia-Wei; Chen, J. Don

    2007-01-01

    The ankyrin repeats cofactor-1 (ANCO-1) was recently identified as a p160 coactivator-interacting protein that may inhibit transcriptional activity of nuclear receptors. Here, we have characterized the transcriptional regulatory domains of ANCO-1. Two intrinsic repression domains (RD) were identified: an N-terminal RD1 at residues 318-611 and a C-terminal RD2 at 2369-2663. ANCO-1 also contains an activation domain (AD) capable of stimulating transcription in both mammalian and yeast cells. The minimal AD was delimited to a 70-amino acid region at residues 2076-2145. Overall, full-length ANCO-1 exhibited transcriptional repressor activity, suggesting that RD domains may suppress the AD activity. We further demonstrated that ANCO-1 silencing by siRNA enhanced progesterone receptor-mediated transcription. Together, these results indicate that the transcriptional potential of ANCO-1 may be modulated by a combination of repression and activation signals

  14. Genetic screen for regulatory mutations in Methanococcus maripaludis and its use in identification of induction-deficient mutants of the euryarchaeal repressor NrpR.

    Science.gov (United States)

    Lie, Thomas J; Leigh, John A

    2007-10-01

    NrpR is an euryarchaeal transcriptional repressor of nitrogen assimilation genes. Previous studies with Methanococcus maripaludis demonstrated that NrpR binds to palindromic operator sequences, blocking transcription initiation. The metabolite 2-oxoglutarate, an indicator of cellular nitrogen deficiency, induces transcription by lowering the affinity of NrpR for operator DNA. In this report we build on existing genetic tools for M. maripaludis to develop a screen for change-of-function mutations in a transcriptional regulator and demonstrate the use of an X-Gal (5-bromo-4-chloro-3-indolyl-beta-d-galactopyranoside) screen for strict anaerobes. We use the approach to address the primary structural requirements for the response of NrpR to 2-oxoglutarate. nrpR genes from the mesophilic M. maripaludis and the hyperthermophilic Methanopyrus kandleri were targeted for mutagenesis. M. maripaludis nrpR encodes a protein with two homologous NrpR domains while the M. kandleri nrpR homolog encodes a single NrpR domain. Random point mutagenesis and alanine replacement mutagenesis identified two amino acid residues of M. kandleri NrpR involved in induction of gene expression under nitrogen-deficient conditions and thus in the response to 2-oxoglutarate. Mutagenesis of the corresponding regions in either domain of M. maripaludis NrpR resulted in a similar effect, demonstrating a conserved structure-function relationship between the two repressors. The results indicate that in M. maripaludis, both NrpR domains participate in the 2-oxoglutarate response. The approach used here has wide adaptability to other regulatory systems in methanogenic Archaea and other strict anaerobes.

  15. Alanine screening mutagenesis establishes the critical inactivating damage of irradiated E. coli lactose repressor.

    Science.gov (United States)

    Goffinont, Stephane; Villette, Sandrine; Spotheim-Maurizot, Melanie

    2012-06-01

    The function of the E. coli lactose operon requires the binding of lactose repressor to operator DNA. We have previously shown that γ rradiation destabilizes the repressor-operator complex because the repressor loses its DNA-binding ability. It was suggested that the observed oxidation of the four tyrosines (Y7, Y12, Y17, Y47) and the concomitant structural changes of the irradiated DNA-binding domains (headpieces) could be responsible for the inactivation. To pinpoint the tyrosine whose oxidation has the strongest effect, four headpieces containing the product of tyrosine oxidation, 3,4-dihydroxyphenylalanine (DOPA), were simulated by molecular dynamics. We have observed that replacing Y47 by DOPA triggers the largest change of structure and stability of the headpiece and have concluded that Y47 oxidation is the greatest contributor to the decrease of repressor binding to DNA. To experimentally verify this conclusion, we applied the alanine screening mutagenesis approach. Tetrameric mutated repressors bearing an alanine instead of each one of the tyrosines were prepared and their binding to operator DNA was checked. Their binding ability is quite similar to that of the wild-type repressor, except for the Y47A mutant whose binding is strongly reduced. Circular dichroism determinations revealed small reductions of the proportion of α helices and of the melting temperature for Y7A, Y12A and Y17A headpieces, but much larger ones were revealed for Y47A headpiece. These results established the critical role of Y47 oxidation in modifying the structure and stability of the headpiece, and in reduction of the binding ability of the whole lactose repressor.

  16. Modular Synthetic Inverters from Zinc Finger Proteins and Small RNAs.

    Directory of Open Access Journals (Sweden)

    Justin Hsia

    Full Text Available Synthetic zinc finger proteins (ZFPs can be created to target promoter DNA sequences, repressing transcription. The binding of small RNA (sRNA to ZFP mRNA creates an ultrasensitive response to generate higher effective Hill coefficients. Here we combined three "off the shelf" ZFPs and three sRNAs to create new modular inverters in E. coli and quantify their behavior using induction fold. We found a general ordering of the effects of the ZFPs and sRNAs on induction fold that mostly held true when combining these parts. We then attempted to construct a ring oscillator using our new inverters. Our chosen parts performed insufficiently to create oscillations, but we include future directions for improvement upon our work presented here.

  17. Enhanced protein production by engineered zinc finger proteins.

    Science.gov (United States)

    Reik, Andreas; Zhou, Yuanyue; Collingwood, Trevor N; Warfe, Lyndon; Bartsevich, Victor; Kong, Yanhong; Henning, Karla A; Fallentine, Barrett K; Zhang, Lei; Zhong, Xiaohong; Jouvenot, Yann; Jamieson, Andrew C; Rebar, Edward J; Case, Casey C; Korman, Alan; Li, Xiao-Yong; Black, Amelia; King, David J; Gregory, Philip D

    2007-08-01

    Increasing the yield of therapeutic proteins from mammalian production cell lines reduces costs and decreases the time to market. To this end, we engineered a zinc finger protein transcription factor (ZFP TF) that binds a DNA sequence within the promoter driving transgene expression. This ZFP TF enabled >100% increase in protein yield from CHO cells in transient, stable, and fermentor production run settings. Expression vectors engineered to carry up to 10 ZFP binding sites further enhanced ZFP-mediated increases in protein production up to approximately 500%. The multimerized ZFP binding sites function independently of the promoter, and therefore across vector platforms. CHO cell lines stably expressing ZFP TFs demonstrated growth characteristics similar to parental cell lines. ZFP TF expression and gains in protein production were stable over >30 generations in the absence of antibiotic selection. Our results demonstrate that ZFP TFs can rapidly and stably increase protein production in mammalian cells. (c) 2006 Wiley Periodicals, Inc.

  18. Admittance Control of a Multi-Finger Arm Based on Manipulability of Fingers

    Directory of Open Access Journals (Sweden)

    Jian Huang

    2011-09-01

    Full Text Available In the previous studies, admittance control and impedance control for a finger-arm robot using the manipulability of the finger were studied and methods of realizing the controls have been proposed. In this study, two 3-DOF fingers are attached to the end-effector of a 6-DOF arm to configure a multi-finger arm robot. Based on the previous methods, the authors have proposed an admittance control for a multi-finger arm robot using the manipulability of the fingers in this study. Algorithms of the averaging method and the mini-max method were introduced to establish a manipulability criterion of the two fingers in order to generate a cooperative movement of the arm. Comparison of the admittance controls combined with the top search method and local optimization method for the multi-finger arm robot was made and features of the control methods were also discussed. The stiffness control and damping control were experimentally evaluated to demonstrate the effectiveness of the proposed methods.

  19. Robotic finger perturbation training improves finger postural steadiness and hand dexterity.

    Science.gov (United States)

    Yoshitake, Yasuhide; Ikeda, Atsutoshi; Shinohara, Minoru

    2018-02-01

    The purpose of the study was to understand the effect of robotic finger perturbation training on steadiness in finger posture and hand dexterity in healthy young adults. A mobile robotic finger training system was designed to have the functions of high-speed mechanical response, two degrees of freedom, and adjustable loading amplitude and direction. Healthy young adults were assigned to one of the three groups: random perturbation training (RPT), constant force training (CFT), and control. Subjects in RPT and CFT performed steady posture training with their index finger using the robot in different modes: random force in RPT and constant force in CFT. After the 2-week intervention period, fluctuations of the index finger posture decreased only in RPT during steady position-matching tasks with an inertial load. Purdue pegboard test score improved also in RPT only. The relative change in finger postural fluctuations was negatively correlated with the relative change in the number of completed pegs in the pegboard test in RPT. The results indicate that finger posture training with random mechanical perturbations of varying amplitudes and directions of force is effective in improving finger postural steadiness and hand dexterity in healthy young adults. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Sequence-specific DNA binding by glucocorticoid receptor "zinc finger peptides".

    OpenAIRE

    Archer, T K; Hager, G L; Omichinski, J G

    1990-01-01

    Steroid hormone receptors can activate or repress transcription from responsive loci by binding to DNA. We have examined the mechanism of DNA binding by individually synthesizing the putative "zinc finger peptides" from the rat glucocorticoid receptor. Atomic absorption studies show that the peptides will bind zinc on an equimolar basis, and circular dichroism experiments demonstrate a significant alteration in secondary structure in the presence of zinc. The results from a series of experime...

  1. A Novel Strategy for Controlling the Metastatic Phenotype: Targeting the SNAG Repression Domain in the SNAIL Zinc-Finger Protein

    Science.gov (United States)

    2007-07-01

    A. H., Ganss, B., Cheifetz, S. & Sodek, J. (2001). Characterization of a novel KRAB/C2H2 zinc finger transcription factor involved in bone ...peritoneal mesothelial cells. Int J Artif Organs 28:164-9. 2. Ancelin, K., U. C. Lange, P. Hajkova, R. Schneider, A. J. Bannister, T. Kouzarides, and M. A

  2. Tendon displacements during voluntary and involuntary finger movements.

    Science.gov (United States)

    van Beek, Nathalie; Gijsbertse, Kaj; Selles, Ruud W; de Korte, Chris L; Veeger, DirkJan H E J; Stegeman, Dick F; Maas, Huub

    2018-01-23

    In the human hand, independent movement control of individual fingers is limited. One potential cause for this is mechanical connections between the tendons and muscle bellies corresponding to the different fingers. The aim of this study was to determine the tendon displacement of the flexor digitorum superficialis (FDS) of both the instructed and the neighboring, non-instructed fingers during single finger flexion movements. In nine healthy subjects (age 22-29 years), instructed and non-instructed FDS finger tendon displacement of the index, middle and ring finger was measured using 2D ultrasound analyzed with speckle tracking software in two conditions: active flexion of all finger joints with all fingers free to move and active flexion while the non-instructed fingers were restricted. Our results of the free movement protocol showed an average tendon displacement of 27 mm for index finger flexion, 21 mm for middle finger flexion and 17 mm for ring finger flexion. Displacements of the non-instructed finger tendons (≈12 mm) were higher than expected based of the amount of non-instructed finger movement. In the restricted protocol, we found that, despite minimal joint movements, substantial non-instructed finger tendon displacement (≈9 mm) was still observed, which was interpreted as a result of tendon strain. When this strain component was subtracted from the tendon displacement of the non-instructed fingers during the free movement condition, the relationship between finger movement and tendon displacement of the instructed and non-instructed finger became comparable. Thus, when studying non-instructed finger tendon displacement it is important to take tendon strain into consideration. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Gravity Induced Ordering of Frictional Fingers

    Science.gov (United States)

    Eriksen, Jon; Sandnes, Bjørnar; Toussaint, Renaud; Jørgen Måløy, Knut; Flekkøy, Eirik

    2014-05-01

    Experiments on confined two-phase flow systems, involving air and a dense suspension, have revealed highly non-trivial flow morphologies. As the air displaces the suspension, the grains that make up the suspension tend to accumulate along the interface, and can build up force chains that jam the accumulated region. This dynamics will generate "frictional fingers" of air coated by a region of densely packed grains. The fingers have a characteristic width that balances surface tension and frictional forces of the densely packed grains. When these fingers grow under the influence of gravity, they can align either horizontally or vertically, or grow in a random isotropic fashion. The transition between the different modes of finger growth depends on the density of grains, and the gravitational force component. We present an analytic model to account for the transitions between the modes. We further present a numerical scheme that enables us to simulate the dynamics of the process. The numerical and analytic results are in good agreements with the experimental findings. Finally we show how this process could explain patterns that emerge naturally in early stages of dyke formation. These patterns are formed when hot fluid displaces partly molten rocks and packs the hard mineral grains composing it together, thereby forming finger structures that remain frozen in the dyke walls.

  4. Saffman-Taylor fingers with kinetic undercooling

    KAUST Repository

    Gardiner, Bennett P. J.

    2015-02-23

    © 2015 American Physical Society. The mathematical model of a steadily propagating Saffman-Taylor finger in a Hele-Shaw channel has applications to two-dimensional interacting streamer discharges which are aligned in a periodic array. In the streamer context, the relevant regularization on the interface is not provided by surface tension but instead has been postulated to involve a mechanism equivalent to kinetic undercooling, which acts to penalize high velocities and prevent blow-up of the unregularized solution. Previous asymptotic results for the Hele-Shaw finger problem with kinetic undercooling suggest that for a given value of the kinetic undercooling parameter, there is a discrete set of possible finger shapes, each analytic at the nose and occupying a different fraction of the channel width. In the limit in which the kinetic undercooling parameter vanishes, the fraction for each family approaches 1/2, suggesting that this "selection" of 1/2 by kinetic undercooling is qualitatively similar to the well-known analog with surface tension. We treat the numerical problem of computing these Saffman-Taylor fingers with kinetic undercooling, which turns out to be more subtle than the analog with surface tension, since kinetic undercooling permits finger shapes which are corner-free but not analytic. We provide numerical evidence for the selection mechanism by setting up a problem with both kinetic undercooling and surface tension and numerically taking the limit that the surface tension vanishes.

  5. Viscoelastic fingering with a pulsed pressure signal

    International Nuclear Information System (INIS)

    Corvera Poire, E; Rio, J A del

    2004-01-01

    We derive a generalized Darcy's law in the frequency domain for a linear viscoelastic fluid flowing in a Hele-Shaw cell. This leads to an analytic expression for the dynamic permeability that has maxima which are several orders of magnitude larger than the static permeability. We then follow an argument of de Gennes (1987 Europhys. Lett. 2 195) to obtain the smallest possible finger width when viscoelasticity is important. Using this and a conservation law, we obtain the lowest bound for the width of a single finger displacing a viscoelastic fluid. When the driving force consists of a constant pressure gradient plus an oscillatory signal, our results indicate that the finger width varies in time following the frequency of the incident signal. Also, the amplitude of the finger width in time depends on the value of the dynamic permeability at the imposed frequency. When the finger is driven with a frequency that maximizes the permeability, variations in the amplitude are also maximized. This gives results that are very different for Newtonian and viscoelastic fluids. For the former ones the amplitude of the oscillation decays with frequency. For the latter ones on the other hand, the amplitude has maxima at the same frequencies that maximize the dynamic permeability

  6. Comparing native and irradiated E. coli lactose repressor-operator complex by molecular dynamics simulation.

    Science.gov (United States)

    Aci-Sèche, Samia; Garnier, Norbert; Goffinont, Stéphane; Genest, Daniel; Spotheim-Maurizot, Mélanie; Genest, Monique

    2010-09-01

    The function of the E. coli lactose operon requires the binding of the tetrameric repressor protein to the operator DNA. We have previously shown that gamma-irradiation destabilises the repressor-operator complex because the repressor gradually loses its DNA-binding ability (Radiat Res 170:604-612, 2008). It was suggested that the observed oxidation of tyrosine residues and the concomitant structural changes of irradiated headpieces (DNA-binding domains of repressor monomers) could be responsible for the inactivation. To unravel the mechanisms that lead to repressor-operator complex destabilisation when tyrosine oxidation occurs, we have compared by molecular dynamic simulations two complexes: (1) the native complex formed by two headpieces and the operator DNA, and (2) the damaged complex, in which all tyrosines are replaced by their oxidation product 3,4-dihydroxyphenylalanine (DOPA). On a 20 ns time scale, MD results show effects consistent with complex destabilisation: increased flexibility, increased DNA bending, modification of the hydrogen bond network, and decrease of the positive electrostatic potential at the protein surface and of the global energy of DNA-protein interactions.

  7. Perceiving fingers in single-digit arithmetic problems

    Directory of Open Access Journals (Sweden)

    Ilaria eBerteletti

    2015-03-01

    Full Text Available In this study, we investigate in children the neural underpinnings of finger representation and finger movement involved in single-digit arithmetic problems. Evidence suggests that finger representation and finger-based strategies play an important role in learning and understanding arithmetic. Because different operations rely on different networks, we compared activation for subtraction and multiplication problems in independently localized finger somatosensory and motor areas and tested whether activation was related to skill. Brain activations from children between 8 and 13 years of age revealed that only subtraction problems significantly activated finger motor areas, suggesting reliance on finger-based strategies. In addition, larger subtraction problems yielded greater somatosensory activation than smaller problems, suggesting a greater reliance on finger representation for larger numerical values. Interestingly, better performance in subtraction problems was associated with lower activation in the finger somatosensory area. Our results support the importance of fine-grained finger representation in arithmetical skill and are the first neurological evidence for a functional role of the somatosensory finger area in proficient arithmetical problem solving, in particular for those problems requiring quantity manipulation. From an educational perspective, these results encourage investigating whether different finger-based strategies facilitate arithmetical understanding and encourage educational practices aiming at integrating finger representation and finger-based strategies as a tool for instilling stronger numerical sense.

  8. Transcriptional activation of NAD+-dependent protein deacetylase SIRT1 by nuclear receptor TLX

    International Nuclear Information System (INIS)

    Iwahara, Naotoshi; Hisahara, Shin; Hayashi, Takashi; Horio, Yoshiyuki

    2009-01-01

    An orphan nuclear receptor TLX is a transcriptional repressor that promotes the proliferation and self-renewal of neural precursor cells (NPCs). SIRT1, an NAD + -dependent protein deacetylase, is highly expressed in the NPCs and participates in neurogenesis. Here, we found that TLX colocalized with SIRT1 and knockdown of TLX by small interfering RNAs decreased SIRT1 levels in NPCs. TLX increased the SIRT1 expression by binding to the newly identified TLX-activating element in the SIRT1 gene promoter in HEK293 cells. Thus, TLX is an inducer of SIRT1 and may contribute to neurogenesis both as a transactivator and as a repressor.

  9. Finger forces in fastball baseball pitching.

    Science.gov (United States)

    Kinoshita, Hiroshi; Obata, Satoshi; Nasu, Daiki; Kadota, Koji; Matsuo, Tomoyuki; Fleisig, Glenn S

    2017-08-01

    Forces imparted by the fingers onto a baseball are the final, critical aspects for pitching, however these forces have not been quantified previously as no biomechanical technology was available. In this study, an instrumented baseball was developed for direct measurement of ball reaction force by individual fingers and used to provide fundamental information on the forces during a fastball pitch. A tri-axial force transducer with a cable having an easily-detachable connector were installed in an official baseball. Data were collected from 11 pitchers who placed the fingertip of their index, middle, ring, or thumb on the transducer, and threw four-seam fastballs to a target cage from a flat mound. For the index and middle fingers, resultant ball reaction force exhibited a bimodal pattern with initial and second peaks at 38-39ms and 6-7ms before ball release, and their amplitudes were around 97N each. The ring finger and thumb produced single-peak forces of approximately 50 and 83N, respectively. Shear forces for the index and middle fingers formed distinct peak at 4-5ms before release, and the peaks summed to 102N; a kinetic source for backspin on the ball. An additional experiment with submaximal pitching effort showed a linear relationship of peak forces with ball velocity. The peak ball reaction force for fastballs exceeded 80% of maximum finger strength measured, suggesting that strengthening of the distal muscles is important both for enhancing performance and for avoiding injuries. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Zinc-finger nucleases: a panoramic view.

    Science.gov (United States)

    Carroll, Dana

    2011-02-01

    Zinc-finger nucleases (ZFNs) are emerging as very powerful tools for directed genome modifications. Their key features are: a DNA-binding domain comprised of zinc fingers that can be designed to favor very specific targets; a nonspecific cleavage domain that must dimerize to cut DNA--this requirement enhances specificity and minimizes random cleavage. ZFNs have been shown to be effective in a wide range of organisms and cell types. This article reviews discoveries that led to the development of ZFNs, cites examples of successes in genome engineering, and projects how ZFNs may be used in the future, particularly in applications to humans.

  11. Contamination by human fingers. The Midas touch

    International Nuclear Information System (INIS)

    Gwozdz, R.; Grass, F.

    2004-01-01

    Anthropogenic activity is one of the causes of contamination in the human environment: contamination of air, water, top soils, plants and food products has complex effects on human health problems. Wear and abrasion of various surfaces are constant processes in daily life, and commonly include interaction between human fingers and surfaces of every conceivable material. New methods for investigation of trace transfer processes by human fingers are described. Results of transfer for commonly used metals such as gold, silver, zinc, cadmium, tin, cobalt, nickel, chromium and iron are presented. Relationship between transfer of metals by touch and the general problem of purity in analytical activities is briefly discussed. (author)

  12. Lactose repressor protein modified with dansyl chloride: activity effects and fluorescence properties

    International Nuclear Information System (INIS)

    Hsieh, W.T.; Matthews, K.S.

    1985-01-01

    Chemical modification using 5-(dimethylamino)naphthalene-1-sulfonyl chloride (dansyl chloride) has been used to explore the importance of lysine residues involved in the binding activities of the lactose repressor and to introduce a fluorescent probe into the protein. Dansyl chloride modification of lac repressor resulted in loss of operator DNA binding at low molar ratios of reagent/monomer. Loss of nonspecific DNA binding was observed only at higher molar ratios, while isopropyl beta-D-thiogalactoside binding was not affected at any of the reagent levels studied. Lysine residues were the only modified amino acids detected. Protection of lysines-33 and -37 from modification by the presence of nonspecific DNA correlated with maintenance of operator DNA binding activity, and reaction of lysine-37 paralleled operator binding activity loss. Energy transfer between dansyl incorporated in the core region of the repressor protein and tryptophan-201 was observed, with an approximate distance of 23 A calculated between these two moieties

  13. Admittance Control of a Multi-Finger Arm Based on Manipulability of Fingers

    Directory of Open Access Journals (Sweden)

    Takayuki Hori

    2011-09-01

    Full Text Available In the previous studies, admittance control and impedance control for a finger‐arm robot using the manipulability of the finger were studied and methods of realizing the controls have been proposed. In this study, two 3‐DOF fingers are attached to the end‐effector of a 6‐DOF arm to configure a multi‐finger arm robot. Based on the previous methods, the authors have proposed an admittance control for a multi‐finger arm robot using the manipulability of the fingers in this study. Algorithms of the averaging method and the mini‐max method were introduced to establish a manipulability criterion of the two fingers in order to generate a cooperative movement of the arm. Comparison of the admittance controls combined with the top search method and local optimization method for the multi‐finger arm robot was made and features of the control methods were also discussed. The stiffness control and damping control were experimentally evaluated to demonstrate the effectiveness of the proposed methods.

  14. The Arabidopsis SUPERMAN protein is able to specifically bind DNA through its single Cys2-His2 zinc finger motif.

    Science.gov (United States)

    Dathan, Nina; Zaccaro, Laura; Esposito, Sabrina; Isernia, Carla; Omichinski, James G; Riccio, Andrea; Pedone, Carlo; Di Blasio, Benedetto; Fattorusso, Roberto; Pedone, Paolo V

    2002-11-15

    The Arabidopsis SUPERMAN (SUP) gene has been shown to be important in maintaining the boundary between stamens and carpels, and is presumed to act by regulating cell proliferation. In this work, we show that the SUP protein, which contains a single Cys2-His2 zinc finger domain including the QALGGH sequence, highly conserved in the plant zinc finger proteins, binds DNA. Using a series of deletion mutants, it was determined that the minimal domain required for specific DNA binding (residues 15-78) includes the single zinc finger and two basic regions located on either side of this motif. Furthermore, amino acid substitutions in the zinc finger or in the basic regions, including a mutation that knocks out the function of the SUP protein in vivo (glycine 63 to aspartate), have been found to abolish the activity of the SUP DNA-binding domain. These results strongly suggest that the SUP protein functions in vivo by acting as a DNA-binding protein, likely involved in transcriptional regulation. The association of both an N-terminal and a C-terminal basic region with a single Cys2-His2 zinc finger represents a novel DNA-binding motif suggesting that the mechanism of DNA recognition adopted by the SUP protein is different from that described so far in other zinc finger proteins.

  15. The transcription factor DREAM represses A20 and mediates inflammation

    OpenAIRE

    Tiruppathi, Chinnaswamy; Soni, Dheeraj; Wang, Dong-Mei; Xue, Jiaping; Singh, Vandana; Thippegowda, Prabhakar B.; Cheppudira, Bopaiah P.; Mishra, Rakesh K.; DebRoy, Auditi; Qian, Zhijian; Bachmaier, Kurt; Zhao, Youyang; Christman, John W.; Vogel, Stephen M.; Ma, Averil

    2014-01-01

    Here we show that the transcription-repressor DREAM binds to the A20 promoter to repress the expression of A20, the deubiquitinase suppressing inflammatory NF-κB signaling. DREAM-deficient (Dream−/− ) mice displayed persistent and unchecked A20 expression in response to endotoxin. DREAM functioned by transcriptionally repressing A20 through binding to downstream regulatory elements (DREs). In contrast, USF1 binding to the DRE-associated E-box domain activated A20 expression in response to inf...

  16. ANALYSIS WITH MSC ADAMS OF A 5-FINGER AND 3-PHALANX /FINGER UNDER-ACTUATEDMECHANICAL HAND

    Directory of Open Access Journals (Sweden)

    Gheorghe POPESCU

    2013-05-01

    Full Text Available This paper studies the analysis with MSC ADAMS of a 5-fingered and 3-phalanx/finger underactuatedmechanical hand, designed by the author to work on industrial robots. Moreover, in order to increasegrasping safety in the automated handling process, the author has fitted each finger with a locking sequence inthe final phase of grasping. Thus, the mechanism of mechanical hand is considered to be a mechanical systemand is treated like a set of rigid bodies connected by mechanical linkages and elastic elements. To model andsimulate this mechanism with MSC ADAMS programme, the author covered the following stages: constructionof the model, testing-simulation, validation, finishing, parameterization, and optimization

  17. Lysogenic induction in Lex Al Escherichia coli mutants: characterization of the induction and prophage repressor influence

    International Nuclear Information System (INIS)

    Carvalho, R.E.S.

    1982-01-01

    SOS functions require new synthesis of protein and have been described as dependent on both the rec A and lex A genes. The induction of prophage was studied in bacterial strains lysogenic for a series of phages which synthesize different levels of repressor (λ, λ i m m 4 3 4 J and λ i m m 4 3 4 T ) and was compared to W-reactivation. Prophage induction was detected in lex Al mutants although at a slightly lower level and requiring two times longer when compared with wild-type. The optimum UV-dose for induction differed for each lysogenic strain and correlated with the level of repressor

  18. Cloning, expression, crystallization and preliminary X-ray analysis of a putative multiple antibiotic resistance repressor protein (MarR) from Xanthomonas campestris

    International Nuclear Information System (INIS)

    Tu, Zhi-Le; Li, Juo-Ning; Chin, Ko-Hsin; Chou, Chia-Cheng; Lee, Cheng-Chung; Shr, Hui-Lin; Lyu, Ping-Chiang; Gao, Fei Philip; Wang, Andrew H.-J.; Chou, Shan-Ho

    2005-01-01

    A putative repressor for the multiple antibiotic resistance operon from a plant pathogen X. campestris pv. campestris has been overexpressed in E. coli, purified and crystallized. The crystals diffracted to 2.3 Å with good quality. The multiple antibiotic resistance operon (marRAB) is a member of the multidrug-resistance system. When induced, this operon enhances resistance of bacteria to a variety of medically important antibiotics, causing a serious global health problem. MarR is a marR-encoded protein that represses the transcription of the marRAB operon. Through binding with salicylate and certain antibiotics, however, MarR can derepress and activate the marRAB operon. In this report, the cloning, expression, crystallization and preliminary X-ray analysis of XC1739, a putative MarR repressor protein present in the Xanthomonas campestris pv. campestris, a Gram-negative bacterium causing major worldwide disease of cruciferous crops, are described. The XC1739 crystals diffracted to a resolution of at least 1.8 Å. They are orthorhombic and belong to space group P2 1 2 1 2 1 , with unit-cell parameters a = 39.5, b = 54.2 and c = 139.5 Å, respectively. They contain two molecules in the asymmetric unit from calculation of the self-rotation function

  19. Characterization and purification of Adh distal promoter factor 2, Adf-2, a cell-specific and promoter-specific repressor in Drosophila.

    Science.gov (United States)

    Benyajati, C; Ewel, A; McKeon, J; Chovav, M; Juan, E

    1992-09-11

    Chromatin footprinting in Drosophila tissue culture cells has detected the binding of a non-histone protein at +8 of the distal Adh RNA start site, on a 10-bp direct repeat motif abutting a nucleosome positioned over the inactive Adh distal promoter. Alternatively the active promoter is bound by a transcription initiation complex. We have characterized and purified a protein Adf-2 that binds specifically to this direct repeat motif 5'TCTCAGTGCA3', present at +8 and -202 of the distal RNA start site. DNase I footprinting, methylation interference, and UV-crosslinking analyses showed that both direct repeats interact in vitro with a nuclear protein of approximately 120 kilodaltons (kDa). We purified Adf-2 through multiple rounds of sequence-specific DNA affinity chromatography. Southwestern analysis showed that the purified 120 KDa polypeptide binds the Adf-2 motif efficiently as a monomer or homomultimer. In vivo titrations of Adf-2 activity with the Adf-2 motif by transient co-transfection competitions in different Drosophila cell lines suggested that Adf-2 is a cell-specific repressor. Adf-2 has been detected ubiquitously in vitro, but is functional in vivo as a sequence-specific DNA binding protein and repressor only in the cells that have the inactive distal promoter. We discuss the possibility that an activation process is required for Adf-2 protein to bind DNA and function in vivo.

  20. Task specificity of finger dexterity tests

    NARCIS (Netherlands)

    Berger, M.A.M.; Krul, A.; Daanen, H.A.M.

    2009-01-01

    Finger dexterity tests are generally used to assess performance decrease due to gloves, cold and pathology. It is generally assumed that the O’Connor and Purdue Pegboard test yield similar results. In this experiment we compared these two tests for dry conditions without gloves, and for dry and wet

  1. Task specificity of finger dexterity tests

    NARCIS (Netherlands)

    Berger, M.A.M.; Krul, A.J.; Daanen, H.A.M.

    2009-01-01

    Finger dexterity tests are generally used to assess performance decrease due to gloves, cold and pathology. It is generally assumed that the O'Connor and Purdue Pegboard test yield similar results. In this experiment we compared these two tests for dry conditions without gloves, and for dry and wet

  2. Finger cold-induced vasodilation : A review

    NARCIS (Netherlands)

    Daanen, H. A M

    Cold-induced vasodilation (CIVD) in the finger tips generally occurs 5-10 min after the start of local cold exposure of the extremities. This phenomenon is believed to reduce the risk of local cold injuries. However, CIVD is almost absent during hypothermia, when survival of the organism takes

  3. Treatment Options for Mallet Finger : A Review

    NARCIS (Netherlands)

    Smit, Jeroen M.; Beets, Michiel R.; Zeebregts, Clark J.; Rood, Akkie; Welters, Carlo F. M.

    2010-01-01

    Background: Mallet finger is a common injury. The aim of this review is to give an overview of the different treatment options of mallet injuries and their indications, outcomes, and potential complications. Methods: A literature-based study was conducted using the PubMed database comprising world

  4. Clubbed fingers: the claws we lost?

    NARCIS (Netherlands)

    Brouwers, A.A.M.; Vermeij-Keers, C.; Zoelen, E.J.J. van; Gooren, L.J.G.

    2004-01-01

    Clubbed digits resemble the human embryonic fingers and toes, which took like the digits of a claw. Clubbed digits, thus, may represent the return of the embryonic claw and may even represent the claws man has lost during evolution, if ontogenesis realty recapitulates phylogenesis. We put forward

  5. Finger Search in Grammar-Compressed Strings

    DEFF Research Database (Denmark)

    Bille, Philip; Christiansen, Anders Roy; Cording, Patrick Hagge

    2016-01-01

    random access, that is, given a position in the original uncompressed string report the character at that position. In this paper we study the random access problem with the finger search property, that is, the time for a random access query should depend on the distance between a specified index f...

  6. Designing Fingers in Simulation based on Imprints

    DEFF Research Database (Denmark)

    Wiuf Schwartz, Lukas Christoffer Malte; Wolniakowski, Adam; Werner, Andrzej

    2017-01-01

    Gripper design is nowadays an area of ongoing research activity. The problem of creating a generic and automated gripper design approach tailored for a specific task is still far from solved. In this paper, we propose a new method of generating finger cut-outs aimed at simplifying the design...

  7. Finger cold-induced vasodilation : a review

    NARCIS (Netherlands)

    Daanen, H.A.M.

    2003-01-01

    Cold-induced vasodilation (CIVD) in the finger tips generally occurs 5-10 min after the start of local cold exposure of the extremities. This phenomenon is believed to reduce the risk of local cold injuries. However, CIVD is almost absent during hypothermia, when survival of the organism takes

  8. Cutaneous Microembolism of Fingers and Toes

    OpenAIRE

    Uwe Wollina; André Koch; Birgit Heinig; Georgi Tchernev; Torello Lotti

    2018-01-01

    A macro vascular embolism is a well-known emergency. In contrast, cutaneous microembolism is a lesser known symptom. However, cutaneous microembolism of fingers and toes is a red flag symptom for vascular emergencies. The underlying cause may involve infectious, immunological, metabolic and physical disorders, coagulation disorders and malignancies. Early recognition can help to live safe.

  9. Conservation of the LexA repressor binding site in Deinococcus radiodurans

    Directory of Open Access Journals (Sweden)

    Khan Feroz

    2008-03-01

    Full Text Available The LexA protein is a transcriptional repressor of the bacterial SOS DNA repair system, which comprises a set of DNA repair and cellular survival genes that are induced in response to DNA damage. Its varied DNA binding motifs have been characterized and reported in the Escherichia coli, Bacillus subtilis, rhizobia family members, marine magnetotactic bacterium, Salmonella typhimurium and recently in Mycobacterium tuberculosis and this motifs information has been used in our theoretical analysis to detect its novel regulated genes in radio-resistant Deinococcus radiodurans genome. This bacterium showed presence of SOS-box like consensus sequence in the upstream sequences of 3166 genes with >60% motif score similarity percentage (MSSP on both strands. Attempts to identify LexA-binding sites and the composition of the putative SOS regulon in D. radiodurans have been unsuccessful so far. To resolve the problem we performed theoretical analysis with modifications on reported data set of genes related to DNA repair (61 genes, stress response (145 genes and some unusual predicted operons (21 clusters. Expression of some of the predicted SOS-box regulated operon members then was examined through the previously reported microarray data which confirm the expression of only single predicted operon i.e. DRB0143 (AAA superfamily NTPase related to 5-methylcytosine specific restriction enzyme subunit McrB and DRB0144 (homolog of the McrC subunit of the McrBC restriction modification system. The methodology involved weight matrix construction through CONSENSUS algorithm using information of conserved upstream sequences of eight known genes including dinB, tagC, lexA, recA, uvrB, yneA of B. subtilis while lexA and recA of D. radiodurans through phylogenetic footprinting method and later detection of similar conserved SOS-box like LexA binding motifs through both RSAT & PoSSuMsearch programs. The resultant DNA consensus sequence had highly conserved 14 bp SOS

  10. Strong negative self regulation of Prokaryotic transcription factors increases the intrinsic noise of protein expression

    Directory of Open Access Journals (Sweden)

    Jenkins Dafyd J

    2008-01-01

    Full Text Available Abstract Background Many prokaryotic transcription factors repress their own transcription. It is often asserted that such regulation enables a cell to homeostatically maintain protein abundance. We explore the role of negative self regulation of transcription in regulating the variability of protein abundance using a variety of stochastic modeling techniques. Results We undertake a novel analysis of a classic model for negative self regulation. We demonstrate that, with standard approximations, protein variance relative to its mean should be independent of repressor strength in a physiological range. Consequently, in that range, the coefficient of variation would increase with repressor strength. However, stochastic computer simulations demonstrate that there is a greater increase in noise associated with strong repressors than predicted by theory. The discrepancies between the mathematical analysis and computer simulations arise because with strong repressors the approximation that leads to Michaelis-Menten-like hyperbolic repression terms ceases to be valid. Because we observe that strong negative feedback increases variability and so is unlikely to be a mechanism for noise control, we suggest instead that negative feedback is evolutionarily favoured because it allows the cell to minimize mRNA usage. To test this, we used in silico evolution to demonstrate that while negative feedback can achieve only a modest improvement in protein noise reduction compared with the unregulated system, it can achieve good improvement in protein response times and very substantial improvement in reducing mRNA levels. Conclusion Strong negative self regulation of transcription may not always be a mechanism for homeostatic control of protein abundance, but instead might be evolutionarily favoured as a mechanism to limit the use of mRNA. The use of hyperbolic terms derived from quasi-steady-state approximation should also be avoided in the analysis of stochastic

  11. Novel Dexterous Robotic Finger Concept with Controlled Stiffness

    NARCIS (Netherlands)

    Wassink, M.; Carloni, Raffaella; Brouwer, Dannis Michel; Stramigioli, Stefano

    2009-01-01

    This paper introduces a novel robotic finger concept for variable impedance grasping in unstructured tasks. The novel robotic finger combines three key features: minimal actuation, variable mechanical compliance and full manipulability. This combination of features allows for a minimal component

  12. Activity patterns of extrinsic finger flexors and extensors during movements of instructed and non-instructed fingers.

    Science.gov (United States)

    van Beek, Nathalie; Stegeman, Dick F; van den Noort, Josien C; H E J Veeger, DirkJan; Maas, Huub

    2018-02-01

    The fingers of the human hand cannot be controlled fully independently. This phenomenon may have a neurological as well as a mechanical basis. Despite previous studies, the neuromechanics of finger movements are not fully understood. The aims of this study were (1) to assess the activation and coactivation patterns of finger specific flexor and extensor muscle regions during instructed single finger flexion and (2) to determine the relationship between enslaved finger movements and respective finger muscle activation. In 9 healthy subjects (age 22-29), muscle activation was assessed during single finger flexion using a 90 surface electromyography electrode grid placed over the flexor digitorum superficialis (FDS) and the extensor digitorum (ED). We found (1) no significant differences in muscle activation timing between fingers, (2) considerable muscle activity in flexor and extensor regions associated with the non-instructed fingers and (3) no correlation between the muscle activations and corresponding movement of non-instructed fingers. A clear disparity was found between the movement pattern of the non-instructed fingers and the activity pattern of the corresponding muscle regions. This suggests that mechanical factors, such as intertendinous and myofascial connections, may also affect finger movement independency and need to be taken into consideration when studying finger movement. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Enhancer RNAs and regulated transcriptional programs.

    Science.gov (United States)

    Lam, Michael T Y; Li, Wenbo; Rosenfeld, Michael G; Glass, Christopher K

    2014-04-01

    A large portion of the human genome is transcribed into RNAs without known protein-coding functions, far outnumbering coding transcription units. Extensive studies of long noncoding RNAs (lncRNAs) have clearly demonstrated that they can play critical roles in regulating gene expression, development, and diseases, acting both as transcriptional activators and repressors. More recently, enhancers have been found to be broadly transcribed, resulting in the production of enhancer-derived RNAs, or eRNAs. Here, we review emerging evidence suggesting that at least some eRNAs contribute to enhancer function. We discuss these findings with respect to potential mechanisms of action of eRNAs and other ncRNAs in regulated gene expression. Copyright © 2014. Published by Elsevier Ltd.

  14. Multi-Finger Interaction and Synergies in Finger Flexion and Extension Force Production

    Directory of Open Access Journals (Sweden)

    Jaebum Park

    2017-06-01

    Full Text Available The aim of this study was to discover finger interaction indices during single-finger ramp tasks and multi-finger coordination during a steady state force production in two directions, flexion, and extension. Furthermore, the indices of anticipatory adjustment of elemental variables (i.e., finger forces prior to a quick pulse force production were quantified. It is currently unknown whether the organization and anticipatory modulation of stability properties are affected by force directions and strengths of in multi-finger actions. We expected to observe a smaller finger independency and larger indices of multi-finger coordination during extension than during flexion due to both neural and peripheral differences between the finger flexion and extension actions. We also examined the indices of the anticipatory adjustment between different force direction conditions. The anticipatory adjustment could be a neural process, which may be affected by the properties of the muscles and by the direction of the motions. The maximal voluntary contraction (MVC force was larger for flexion than for extension, which confirmed the fact that the strength of finger flexor muscles (e.g., flexor digitorum profundus was larger than that of finger extensor (e.g., extensor digitorum. The analysis within the uncontrolled manifold (UCM hypothesis was used to quantify the motor synergy of elemental variables by decomposing two sources of variances across repetitive trials, which identifies the variances in the uncontrolled manifold (VUCM and that are orthogonal to the UCM (VORT. The presence of motor synergy and its strength were quantified by the relative amount of VUCM and VORT. The strength of motor synergies at the steady state was larger in the extension condition, which suggests that the stability property (i.e., multi-finger synergies may be a direction specific quantity. However, the results for the existence of anticipatory adjustment; however, no difference

  15. Polycomb repressor complex 1 promotes gene silencing through H2AK119 mono-ubiquitination in acinar-to-ductal metaplasia and pancreatic cancer cells.

    Science.gov (United States)

    Benitz, Simone; Regel, Ivonne; Reinhard, Tobias; Popp, Anna; Schäffer, Isabell; Raulefs, Susanne; Kong, Bo; Esposito, Irene; Michalski, Christoph W; Kleeff, Jörg

    2016-03-08

    Acinar-to-ductal metaplasia (ADM) occurring in cerulein-mediated pancreatitis or in oncogenic Kras-driven pancreatic cancer development is accompanied by extensive changes in the transcriptional program. In this process, acinar cells shut down the expression of acinar specific differentiation genes and re-express genes usually found in embryonic pancreatic progenitor cells. Previous studies have demonstrated that a loss of acinar-specific transcription factors sensitizes the cells towards oncogenic transformation, ultimately resulting in cancer development. However, the mechanism behind the transcriptional silencing of acinar cell fate genes in ADM and pancreatic cancer is largely unknown. Here, we analyzed whether elevated levels of the polycomb repressor complex 1 (PRC1) components Bmi1 and Ring1b and their catalyzed histone modification H2AK119ub in ADMs and tumor cells, are responsible for the mediation of acinar gene silencing. Therefore, we performed chromatin-immunoprecipitation in in vitro generated ADMs and isolated murine tumor cells against the repressive histone modifications H3K27me3 and H2AK119ub. We established that the acinar transcription factor complex Ptf1-L is epigenetically silenced in ADMs as well as in pancreatic tumor cells. For the first time, this work presents a possible mechanism of acinar gene silencing, which is an important prerequisite in the initiation and maintenance of a dedifferentiated cell state in ADMs and tumor cells.

  16. Finger Based Techniques for Nonvisual Touchscreen Text Entry

    OpenAIRE

    Fakrudeen, Mohammed; Yousef, Sufian; Miraz, Mahdi H.; Hussein, AbdelRahman Hamza

    2017-01-01

    This research proposes Finger Based Technique (FBT) for non-visual touch screen device interaction designed for blind users. Based on the proposed technique, the blind user can access virtual keys based on finger holding positions. Three different models have been proposed. They are Single Digit Finger-Digit Input (FDI), Double Digit FDI for digital text entry, and Finger-Text Input (FTI) for normal text entry. All the proposed models were implemented with voice feedback while enabling touch ...

  17. Transition to finger convection in double-diffusive convection

    OpenAIRE

    Kellner, M.; Tilgner, A.

    2014-01-01

    Finger convection is observed experimentally in an electrodeposition cell in which a destabilizing gradient of copper ions is maintained against a stabilizing temperature gradient. This double-diffusive system shows finger convection even if the total density stratification is unstable. Finger convection is replaced by an ordinary convection roll if convection is fast enough to prevent sufficient heat diffusion between neighboring fingers, or if the thermal buoyancy force is less than 1/30 of...

  18. The Arabidopsis floral repressor BFT delays flowering by competing with FT for FD binding under high salinity.

    Science.gov (United States)

    Ryu, Jae Yong; Lee, Hyo-Jun; Seo, Pil Joon; Jung, Jae-Hoon; Ahn, Ji Hoon; Park, Chung-Mo

    2014-02-01

    Soil salinity is one of the most serious agricultural problems that significantly reduce crop yields in the arid and semi-arid regions. It influences various phases of plant growth and developmental processes, such as seed germination, leaf and stem growth, and reproductive propagation. Salt stress delays the onset of flowering in many plant species. We have previously reported that the Arabidopsis BROTHER OF FT AND TFL1 (BFT) acts as a floral repressor under salt stress. However, the molecular mechanisms underlying the BFT function in the salt regulation of flowering induction is unknown. In this work, we found that BFT delays flowering under high salinity by competing with FLOWERING LOCUS T (FT) for binding to the FD transcription factor. The flowering time of FD-deficient fd-2 mutant was insensitive to high salinity. BFT interacts with FD in the nucleus via the C-terminal domain of FD, which is also required for the interaction of FD with FT, and interferes with the FT-FD interaction. These observations indicate that BFT constitutes a distinct salt stress signaling pathway that modulates the function of the FT-FD module and possibly provides an adaptation strategy that fine-tunes photoperiodic flowering under high salinity.

  19. Left hand finger force in violin playing: tempo, loudness, and finger differences.

    Science.gov (United States)

    Kinoshita, Hiroshi; Obata, Satoshi

    2009-07-01

    A three-dimensional force transducer was installed in the neck of a violin under the A string at the D5 position in order to study the force with which the violinist clamps the string against the fingerboard under normal playing conditions. Violinists performed repetitive sequences of open A- and fingered D-tones using the ring finger at tempi of 1, 2, 4, 8, and 16 notes/s at mezzo-forte. At selected tempi, the effects of dynamic level and the use of different fingers were investigated as well. The force profiles were clearly dependent on tempo and dynamic level. At slow tempi, the force profiles were characterized by an initial pulse followed by a level force to the end of the finger contact period. At tempi higher than 2 Hz, only pulsed profiles were observed. The peak force exceeded 4.5 N at 1 and 2 Hz and decreased to 1.7 N at 16 Hz. All force and impulse values were lower at softer dynamic levels, and when using the ring or little finger compared to the index finger.

  20. Production of fish finger from sand smelt ( Atherina boyeri , RISSO ...

    African Journals Online (AJOL)

    In this study, changes of chemical, microbiological load and sensory properties of fish fingers prepared from sand smelt (Atherina boyeri, RISSO 1810) were investigated during storage (for 6 months at -18°C). The fish finger nutritional composition changed with the fish finger process. The changes in moisture, crude protein, ...

  1. The Incidence of Finger Ridge Counts among the Christian ...

    African Journals Online (AJOL)

    The present study was attempted to obtain the occurrence total and absolute finger ridge counts from 102 unrelated Christian populations (60 males and 42 females) of Mysore city, Karnataka state of India. Data were collected by biometric scanner (USB finger print reader). The mean values of Total finger ridge count and ...

  2. Association Between Finger Clubbing and Chronic Lung Disease in ...

    African Journals Online (AJOL)

    Finger clubbed patients had higher risk of hypoxemia (46.7%), pulmonary hypertension (46.7%) and advanced disease in WHO stage III/ IV (91.7%) compared to non-finger clubbed patients. Finger clubbed patients had lower CD4 cells count and percentage (median 369cells, 13%) compared to non-clubbed patients ...

  3. ZBTB7A acts as a tumor suppressor through the transcriptional repression of glycolysis

    Science.gov (United States)

    Liu, Xue-Song; Haines, Jenna E.; Mehanna, Elie K.; Genet, Matthew D.; Ben-Sahra, Issam; Asara, John M.; Manning, Brendan D.

    2014-01-01

    Elevated glycolysis is a common metabolic trait of cancer, but what drives such metabolic reprogramming remains incompletely clear. We report here a novel transcriptional repressor-mediated negative regulation of glycolysis. ZBTB7A, a member of the POK (POZ/BTB and Krüppel) transcription repressor family, directly binds to the promoter and represses the transcription of critical glycolytic genes, including GLUT3, PFKP, and PKM. Analysis of The Cancer Genome Atlas (TCGA) data sets reveals that the ZBTB7A locus is frequently deleted in many human tumors. Significantly, reduced ZBTB7A expression correlates with up-regulation of the glycolytic genes and poor survival in colon cancer patients. Remarkably, while ZBTB7A-deficient tumors progress exceedingly fast, they exhibit an unusually heightened sensitivity to glycolysis inhibition. Our study uncovers a novel tumor suppressor role of ZBTB7A in directly suppressing glycolysis. PMID:25184678

  4. Temporal transcription of the lactococcal temperate phage TP901-1 and DNA sequence of the early promoter region

    DEFF Research Database (Denmark)

    Madsen, Hans Peter Lynge; Hammer, Karin

    1998-01-01

    to a phage repressor, a single-stranded DNA-binding protein, a topoisomerase, a Cro-like protein and two other phage proteins of unknown function were detected. The gene arrangement in the early transcribed region of TP901-1 thus consists of two transcriptional units: one from PR containing four genes...

  5. Radiation-induced oxidative damage to the DNA-binding domain of the lactose repressor

    Czech Academy of Sciences Publication Activity Database

    Gillard, N.; Goffinont, S.; Buré, C.; Davídková, Marie; Maurizot, J. C.; Cadene, M.; Spotheim-Maurizot, M.

    2007-01-01

    Roč. 403, part 3 (2007), s. 463-472 ISSN 0264-6021 R&D Projects: GA MŠk 1P05OC085 Institutional research plan: CEZ:AV0Z10480505 Keywords : ionizing radiation * oxidative damage * DNA binding domain * lac repressor Subject RIV: CE - Biochemistry Impact factor: 4.009, year: 2007

  6. Radiation-induced tetramer-to-dimer transition of Esterichia coli lactose repressor

    Czech Academy of Sciences Publication Activity Database

    Goffinont, S.; Davídková, Marie; Spotheim-Maurizot, M.

    2009-01-01

    Roč. 386, č. 2 (2009), s. 300-304 ISSN 0006-291X R&D Projects: GA MŠk OC09012 Institutional research plan: CEZ:AV0Z10480505 Keywords : protein * DNA * radiation * oxidation * tetramer * dimer * lactose repressor Subject RIV: BO - Biophysics Impact factor: 2.548, year: 2009

  7. Processing bias in anxious subjects and repressors, measured by emotional Stroop interference and attentional allocation.

    NARCIS (Netherlands)

    Brosschot, J.F.; de Ruiter, C.; Kindt, M.

    1999-01-01

    Hypothesized that repressors (Ss high in defensiveness with low trait anxiety) would show cognitive avoidance of threatening information in an attention deployment task, but an attentional bias for the same information in an emotional interference task, while Ss high in anxiety would show a

  8. The CytR repressor antagonizes cyclic AMP-cyclic AMP receptor protein activation of the deoCp2 promoter of Escherichia coli K-12

    DEFF Research Database (Denmark)

    Søgaard-Andersen, Lotte; Martinussen, J; Møllegaard, N E

    1990-01-01

    We have investigated the regulation of the Escherichia coli deoCp2 promoter by the CytR repressor and the cyclic AMP (cAMP) receptor protein (CRP) complexed to cAMP. Promoter regions controlled by these two proteins characteristically contain tandem cAMP-CRP binding sites. Here we show that (i) Cyt......R selectively regulated cAMP-CRP-dependent initiations, although transcription started from the same site in deoCp2 in the absence or presence of cAMP-CRP; (ii) deletion of the uppermost cAMP-CRP target (CRP-2) resulted in loss of CytR regulation, but had only a minor effect on positive control by the cAMP...

  9. The ciliogenic transcription factor RFX3 regulates early midline distribution of guidepost neurons required for corpus callosum development.

    Directory of Open Access Journals (Sweden)

    Carine Benadiba

    Full Text Available The corpus callosum (CC is the major commissure that bridges the cerebral hemispheres. Agenesis of the CC is associated with human ciliopathies, but the origin of this default is unclear. Regulatory Factor X3 (RFX3 is a transcription factor involved in the control of ciliogenesis, and Rfx3-deficient mice show several hallmarks of ciliopathies including left-right asymmetry defects and hydrocephalus. Here we show that Rfx3-deficient mice suffer from CC agenesis associated with a marked disorganisation of guidepost neurons required for axon pathfinding across the midline. Using transplantation assays, we demonstrate that abnormalities of the mutant midline region are primarily responsible for the CC malformation. Conditional genetic inactivation shows that RFX3 is not required in guidepost cells for proper CC formation, but is required before E12.5 for proper patterning of the cortical septal boundary and hence accurate distribution of guidepost neurons at later stages. We observe focused but consistent ectopic expression of Fibroblast growth factor 8 (Fgf8 at the rostro commissural plate associated with a reduced ratio of GLIoma-associated oncogene family zinc finger 3 (GLI3 repressor to activator forms. We demonstrate on brain explant cultures that ectopic FGF8 reproduces the guidepost neuronal defects observed in Rfx3 mutants. This study unravels a crucial role of RFX3 during early brain development by indirectly regulating GLI3 activity, which leads to FGF8 upregulation and ultimately to disturbed distribution of guidepost neurons required for CC morphogenesis. Hence, the RFX3 mutant mouse model brings novel understandings of the mechanisms that underlie CC agenesis in ciliopathies.

  10. A Novel Repressor of the ica Locus Discovered in Clinically Isolated Super-Biofilm-Elaborating Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Liansheng Yu

    2017-01-01

    Full Text Available Staphylococcus aureus TF2758 is a clinical isolate from an atheroma and a super-biofilm-elaborating/polysaccharide intercellular adhesin (PIA/poly-N-acetylglucosamine (PNAG-overproducing strain (L. Shrestha et al., Microbiol Immunol 60:148–159, 2016, https://doi.org/10.1111/1348-0421.12359. A microarray analysis and DNA genome sequencing were performed to identify the mechanism underlying biofilm overproduction by TF2758. We found high transcriptional expression levels of a 7-gene cluster (satf2580 to satf2586 and the ica operon in TF2758. Within the 7-gene cluster, a putative transcriptional regulator gene designated rob had a nonsense mutation that caused the truncation of the protein. The complementation of TF2758 with rob from FK300, an rsbU-repaired derivative of S. aureus strain NCTC8325-4, significantly decreased biofilm elaboration, suggesting a role for rob in this process. The deletion of rob in non-biofilm-producing FK300 significantly increased biofilm elaboration and PIA/PNAG production. In the search for a gene(s in the 7-gene cluster for biofilm elaboration controlled by rob, we identified open reading frame (ORF SAOUHSC_2898 (satf2584. Our results suggest that ORF SAOUHSC_2898 (satf2584 and icaADBC are required for enhanced biofilm elaboration and PIA/PNAG production in the rob deletion mutant. Rob bound to a palindromic sequence within its own promoter region. Furthermore, Rob recognized the TATTT motif within the icaR-icaA intergenic region and bound to a 25-bp DNA stretch containing this motif, which is a critically important short sequence regulating biofilm elaboration in S. aureus. Our results strongly suggest that Rob is a long-sought repressor that recognizes and binds to the TATTT motif and is an important regulator of biofilm elaboration through its control of SAOUHSC_2898 (SATF2584 and Ica protein expression in S. aureus.

  11. Photoperiod-insensitive floral transition in chrysanthemum induced by constitutive expression of chimeric repressor CsLHY-SRDX.

    Science.gov (United States)

    Oda, Atsushi; Higuchi, Yohei; Hisamatsu, Tamotsu

    2017-06-01

    A wide variety of physiological processes including flowering are controlled by the circadian clock in plants. In Arabidopsis, LATE ELONGATED HYPOCOTYL (LHY) and CIRCADIAN CLOCK ASSOCIATED 1 (CCA1) constitute the central oscillator, and their gain of function and loss of function disrupt the circadian clock and affect flowering time through FLOWERING LOCUS T (FT), a gene encoding a florigen. Chrysanthemum is a typical short-day (SD) plant and responds to shortening of day length by the transition from the vegetative to reproductive phase. We identified FLOWERING LOCUS T-LIKE 3 (FTL3) and ANTI-FLORIGENIC FT/TFL1 FAMILY PROTEIN (AFT) as a florigen and antiflorigen, respectively, in a wild diploid chrysanthemum (Chrysanthemum seticuspe f. boreale). CsFTL3 and CsAFT are induced under SD or a noninductive photoperiod, respectively, and their balance determines the floral transition and anthesis. Meanwhile, the time-keeping mechanism that regulates the photoperiodic flowering in chrysanthemum is poorly understood. Here, we focused on a LHY/CCA1-like gene called CsLHY in chrysanthemum. We fused CsLHY to a gene encoding short transcriptional repressor domain (SRDX) and constitutively expressed it in chrysanthemum. Although the transcription of clock-related genes was conditionally affected, circadian rhythm was not completely disrupted in CsLHY-SRDX transgenic plants. These plants formed almost the same number of leaves before floral transition under SD and long-day conditions. Thus, CsLHY-SRDX chrysanthemum showed photoperiod-insensitive floral transition, but further development of the capitulum was arrested, and anthesis was not observed. Simultaneously with the flowering phenotype, CsFTL3 and CsAFT were downregulated in CsLHY-SRDX transgenic plants. These results suggest that CsLHY-SRDX affects CsFTL3 and CsAFT expression and causes photoperiod-insensitive floral transition without a severe defect in the circadian clock. Copyright © 2017 Elsevier B.V. All rights

  12. Regulation of nif expression in Methanococcus maripaludis: roles of the euryarchaeal repressor NrpR, 2-oxoglutarate, and two operators.

    Science.gov (United States)

    Lie, Thomas J; Wood, Gwendolyn E; Leigh, John A

    2005-02-18

    The methanogenic archaean Methanococcus maripaludis can use ammonia, alanine, or dinitrogen as a nitrogen source for growth. The euryarchaeal nitrogen repressor NrpR controls the expression of the nif (nitrogen fixation) operon, resulting in full repression with ammonia, intermediate repression with alanine, and derepression with dinitrogen. NrpR binds to two tandem operators in the nif promoter region, nifOR(1) and nifOR(2). Here we have undertaken both in vivo and in vitro approaches to study the way in which NrpR, nifOR(1), nifOR(2), and the effector 2-oxoglutarate (2OG) combine to regulate nif expression, leading to a comprehensive understanding of this archaeal regulatory system. We show that NrpR binds as a dimer to nifOR(1) and cooperatively as two dimers to both operators. Cooperative binding occurs only with both operators present. nifOR(1) has stronger binding and by itself can mediate the repression of nif transcription during growth on ammonia, unlike the weakly binding nifOR(2). However, nifOR(2) in combination with nifOR(1) is critical for intermediate repression during growth on alanine. Accordingly, NrpR binds to both operators together with higher affinity than to nifOR(1) alone. NrpR responds directly to 2OG, which weakens its binding to the operators. Hence, 2OG is an intracellular indicator of nitrogen deficiency and acts as an inducer of nif transcription via NrpR. This model is upheld by the recent finding (J. A. Dodsworth and J. A. Leigh, submitted for publication) in our laboratory that 2OG levels in M. maripaludis vary with growth on different nitrogen sources.

  13. Characterization of snail1 and pten transcriptional regulation by snail1: New insights into epithelial-to-mesenchymal transition and cell resistance to apoptosis

    OpenAIRE

    Escrivà Izquierdo, María

    2008-01-01

    The product of the snail1 gene (SNAIL1) is a transcriptional repressor required for triggering the epithelial-to-mesenchymal transition (EMT). SNAIL1 transcription is induced when epithelial cells are forced to acquire a mesenchymal phenotype. Furthermore, ectopic expression of snail1 in epithelial cells promotes resistance to apoptosis. In this study, we demonstrate that this resistance to ã radiation-induced apoptosis caused by Snail1 is associated with the transcriptional inhibition of PTE...

  14. Nucleo-cytoplasmic shuttling dynamics of the transcriptional regulators XYR1 and CRE1 under conditions of cellulase and xylanase gene expression in T richoderma reesei

    OpenAIRE

    Lichius, Alexander; Seidl-Seiboth, Verena; Seiboth, Bernhard; Kubicek, Christian P

    2014-01-01

    T richoderma reesei is a model for investigating the regulation of (hemi-)cellulase gene expression. Cellulases are formed adaptively, and the transcriptional activator XYR1 and the carbon catabolite repressor CRE1 are main regulators of their expression. We quantified the nucleo-cytoplasmic shuttling dynamics of GFP-fusion proteins of both transcription factors under cellulase and xylanase inducing conditions, and correlated their nuclear presence/absence with transcriptional changes. We als...

  15. Actin-cytoskeleton polymerization differentially controls the stability of Ski and SnoN co-repressors in normal but not in transformed hepatocytes.

    Science.gov (United States)

    Caligaris, Cassandre; Vázquez-Victorio, Genaro; Sosa-Garrocho, Marcela; Ríos-López, Diana G; Marín-Hernández, Alvaro; Macías-Silva, Marina

    2015-09-01

    Ski and SnoN proteins function as transcriptional co-repressors in the TGF-β pathway. They regulate cell proliferation and differentiation, and their aberrant expression results in altered TGF-β signalling, malignant transformation, and alterations in cell proliferation. We carried out a comparative characterization of the endogenous Ski and SnoN protein regulation by TGF-β, cell adhesion disruption and actin-cytoskeleton rearrangements between normal and transformed hepatocytes; we also analyzed Ski and SnoN protein stability, subcellular localization, and how their protein levels impact the TGF-β/Smad-driven gene transcription. Ski and SnoN protein levels are lower in normal hepatocytes than in hepatoma cells. They exhibit a very short half-life and a nuclear/cytoplasmic distribution in normal hepatocytes opposed to a high stability and restricted nuclear localization in hepatoma cells. Interestingly, while normal cells exhibit a transient TGF-β-induced gene expression, the hepatoma cells are characterized by a strong and sustained TGF-β-induced gene expression. A novel finding is that Ski and SnoN stability is differentially regulated by cell adhesion and cytoskeleton rearrangements in the normal hepatocytes. The inhibition of protein turnover down-regulated both Ski and SnoN co-repressors impacting the kinetic of expression of TGF-β-target genes. Normal regulatory mechanisms controlling Ski and SnoN stability, subcellular localization and expression are altered in hepatocarcinoma cells. This work provides evidence that Ski and SnoN protein regulation is far more complex in normal than in transformed cells, since many of the normal regulatory mechanisms are lost in transformed cells. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Functional characterization of a cadmium resistance operon in Staphylococcus aureus ATCC12600: CadC does not function as a repressor.

    Science.gov (United States)

    Hoogewerf, Arlene J; Dyk, Lisa A Van; Buit, Tyler S; Roukema, David; Resseguie, Emily; Plaisier, Christina; Le, Nga; Heeringa, Lee; Griend, Douglas A Vander

    2015-02-01

    Sequencing of a cadmium resistance operon from a Staphylococcus aureus ATCC12600 plasmid revealed that it is identical to a cadCA operon found in MRSA strains. Compared to plasmid-cured and cadC-mutant strains, cadC-positive ATCC12600 cells had increased resistance to cadmium (1 mg ml(-1) cadmium sulfate) and zinc (4 mg ml(-1) zinc sulfate), but not to other metal ions. After growth in media containing 20 µg ml(-1) cadmium sulfate, cadC-mutant cells contained more intracellular cadmium than cadC-positive ATCC12600 cells, suggesting that cadC absence results in impaired cadmium efflux. Electrophoretic mobility shift assays were performed with CadC proteins encoded by the S. aureus ATCC12600 plasmid and by the cadC gene of pI258, which is known to act as a transcriptional repressor and shares only 47% protein sequence identity with ATCC12600 CadC. Mobility shifts occurred when pI258 CadC protein was incubated with the promoter DNA-regions from the pI258 and S. aureus ATCC12600 cadCA operons, but did not occur with S. aureus ATCC12600 CadC protein, indicating that the ATCC12600 CadC protein does not interact with promoter region DNA. This cadCA operon, found in MRSA strains and previously functionally uncharacterized, increases resistance to cadmium and zinc by an efflux mechanism, and CadC does not function as a transcriptional repressor. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. A Diabetic Elderly Man with Finger Ulcer.

    Science.gov (United States)

    Mohamad, Noraini; Badrin, Salziyan; Wan Abdullah, Wan Noor Hasbee

    2018-03-01

    Fixed cutaneous sporotrichosis is a differential diagnosis that can be considered in diabetic patients who present with a poorly healing ulcer. Although its prevalence is low, it can occur in patients with immunocompromised status. Here we report a case of a 70-year-old man with diabetes mellitus who presented with a 1-month history of an unhealed ulcer over the tip of his left middle finger. He experienced a cat bite over his left middle finger 1 month prior to the appearance of the lesion. A skin biopsy revealed the presence of Sporothrix schenckii . Oral itraconazole 200 mg twice daily was started empirically and the patient showed marked improvement in the skin lesion after 2 months of therapy.

  18. Botulinum toxin injection of spastic finger flexors in hemiplegic patients.

    Science.gov (United States)

    Rodriquez, A A; McGinn, M; Chappell, R

    2000-01-01

    To assess the outcomes of botulinum toxin injection of spastic finger flexors followed by intensive training of finger extensors. Fourteen subjects with chronic hemiplegia spasticity of the upper limb had electromyographic-guided botulinum toxin injection into the long finger flexors. All patients presented with minimal active finger extension with the wrist flexed, sustained clonus of the finger flexors, functional proximal arm function, and absence of fixed contracture. Cadaver dissections directed selection of two injection sites: the flexor digitorum sublimis and the flexor digitorum profundus. Fifty mouse units of botulinum toxin were injected into each muscle. After injection, the subjects were instructed in a home program of stretching the long finger flexors, upper limb weight bearing with a weight-bearing splint, and exercise to improve finger extension control. Compared with preinjection measures, assessment the first week after the initial injection showed significantly reduced tone, reduced clonus, and greater active finger extension with the wrist in the neutral position. Four months later, the Ashworth scale increased to preinjection levels in the six subjects with repeated injections but was again decreased postinjection. Active finger extension with the wrist in the neutral position and clonus showed a statistically nonsignificant trend toward cumulative improvement after the second injection. The greatest change in finger extension and spasticity reduction occurred after the first injection. Continued significant improvement in finger extension was not observed.

  19. Dynamic analysis of C/C composite finger seal

    Directory of Open Access Journals (Sweden)

    Chen Guoding

    2014-06-01

    Full Text Available A seal device as an important component of aeroengines has decisive influence on performance, reliability, and working life of aeroengines. With the development of aeroengines, demands on the performance characteristics of seal devices are made strictly. Finger seal as a novel kind of sealing device, recently attracts more and more attentions in academic circles and engineering fields at home and abroad. Research on finger seals has been extensively developed, especially on leakage and wear performances under dynamic conditions. However, it is a pity that the work on finger seals has been limited with a single approach that is improving the performance by structural optimization; in addition, the technology of dynamic analysis on finger seals is weak. Aiming at the problems mentioned above, a distributed mass equivalent dynamic model of finger seals considering the coupling effect of overlaid laminates is established in the present paper, the dynamic performance of 2.5 dimension C/C composite finger seal is analyzed with the model, and then the effects of fiber bundle density and fiber bundle preparation direction on finger seal’s dynamic performance are discussed, as well as compared with those of Co-based alloy finger seal. The current work is about dynamic analysis of finger seals and application of C/C composite in this paper may have much academic significance and many engineering values for improving research level of finger seal dynamics and exploring feasibility of C/C composite being used for finger seals.

  20. A Parametric Modelling Method for Dexterous Finger Reachable Workspaces

    Directory of Open Access Journals (Sweden)

    Wenzhen Yang

    2016-03-01

    Full Text Available The well-known algorithms, such as the graphic method, analytical method or numerical method, have some defects when modelling the dexterous finger workspace, which is a significant kinematical feature of dexterous hands and valuable for grasp planning, motion control and mechanical design. A novel modelling method with convenient and parametric performances is introduced to generate the dexterous-finger reachable workspace. This method constructs the geometric topology of the dexterous-finger reachable workspace, and uses a joint feature recognition algorithm to extract the kinematical parameters of the dexterous finger. Compared with graphic, analytical and numerical methods, this parametric modelling method can automatically and conveniently construct a more vivid workspace's forms and contours of the dexterous finger. The main contribution of this paper is that a workspace-modelling tool with high interactive efficiency is developed for designers to precisely visualize the dexterous-finger reachable workspace, which is valuable for analysing the flexibility of the dexterous finger.

  1. Finger Search in the Implicit Model

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Nielsen, Jesper Asbjørn Sindahl; Truelsen, Jakob

    2012-01-01

    , and delete in times $\\mathcal{O}(q(t))$, $\\mathcal{O}(q^{-1}(\\log n)\\log n)$, $\\mathcal{O}(\\log n)$, and $\\mathcal{O}(\\log n)$, respectively, for any q(t) = Ω(logt). Finally we show that the search operation must take Ω(logn) time for the special case where the finger is always changed to the element...

  2. Angiolipoma of index finger: A case report

    Directory of Open Access Journals (Sweden)

    Muzaffer Durmus

    2016-04-01

    Full Text Available Angiolipomas are usually found in the upper extremities, shoulder and back. They are seldom found in the hands, face and lower extremities. They usually occur as painful soft tissue masses or they may compress the neighboring structures (e.g. nerves depending on the size and location. In this report we present an angiolipoma case located in the finger and discuss related recent cases described in the literature. [Hand Microsurg 2016; 5(1.000: 22-25

  3. Pacifier Use, Finger Sucking, and Infant Sleep.

    Science.gov (United States)

    Butler, Rachel; Moore, Melisa; Mindell, Jodi A

    2016-01-01

    Few studies to date have investigated the relationship between pacifier use or finger sucking and infant sleep. One hundred and four mothers of infants (ages 0-11 months) completed the Brief Infant Sleep Questionnaire (BISQ). Infants who engaged in finger sucking had fewer night wakings and longer stretches of nighttime sleep, although less daytime sleep. There were no significant differences in sleep patterns between pacifier users and infants who did not engage in nonnutritive sucking. Furthermore, no significant differences were found across groups for sleep ecology, including parental involvement at bedtime and following night wakings. Finally, infants were consistently able to retrieve their pacifiers independently by 7 months of age, although this did not appear to be associated with sleep outcomes. Results suggest that when parents are deciding whether to give their infant a pacifier, sleep may not be a critical factor. In contrast, parents of finger and thumb suckers should be reassured that this nonnutritive sucking is beneficial to sleep, at least in the first year of life.

  4. Visual Foraging With Fingers and Eye Gaze

    Directory of Open Access Journals (Sweden)

    Ómar I. Jóhannesson

    2016-03-01

    Full Text Available A popular model of the function of selective visual attention involves search where a single target is to be found among distractors. For many scenarios, a more realistic model involves search for multiple targets of various types, since natural tasks typically do not involve a single target. Here we present results from a novel multiple-target foraging paradigm. We compare finger foraging where observers cancel a set of predesignated targets by tapping them, to gaze foraging where observers cancel items by fixating them for 100 ms. During finger foraging, for most observers, there was a large difference between foraging based on a single feature, where observers switch easily between target types, and foraging based on a conjunction of features where observers tended to stick to one target type. The pattern was notably different during gaze foraging where these condition differences were smaller. Two conclusions follow: (a The fact that a sizeable number of observers (in particular during gaze foraging had little trouble switching between different target types raises challenges for many prominent theoretical accounts of visual attention and working memory. (b While caveats must be noted for the comparison of gaze and finger foraging, the results suggest that selection mechanisms for gaze and pointing have different operational constraints.

  5. Palm to Finger Ulnar Sensory Nerve Conduction.

    Science.gov (United States)

    Davidowich, Eduardo; Nascimento, Osvaldo J M; Orsini, Marco; Pupe, Camila; Pessoa, Bruno; Bittar, Caroline; Pires, Karina Lebeis; Bruno, Carlos; Coutinho, Bruno Mattos; de Souza, Olivia Gameiro; Ribeiro, Pedro; Velasques, Bruna; Bittencourt, Juliana; Teixeira, Silmar; Bastos, Victor Hugo

    2015-12-29

    Ulnar neuropathy at the wrist (UNW) is rare, and always challenging to localize. To increase the sensitivity and specificity of the diagnosis of UNW many authors advocate the stimulation of the ulnar nerve (UN) in the segment of the wrist and palm. The focus of this paper is to present a modified and simplified technique of sensory nerve conduction (SNC) of the UN in the wrist and palm segments and demonstrate the validity of this technique in the study of five cases of type III UNW. The SNC of UN was performed antidromically with fifth finger ring recording electrodes. The UN was stimulated 14 cm proximal to the active electrode (the standard way) and 7 cm proximal to the active electrode. The normal data from amplitude and conduction velocity (CV) ratios between the palm to finger and wrist to finger segments were obtained. Normal amplitude ratio was 1.4 to 0.76. Normal CV ratio was 0.8 to 1.23.We found evidences of abnormal SNAP amplitude ratio or substantial slowing of UN sensory fibers across the wrist in 5 of the 5 patients with electrophysiological-definite type III UNW.

  6. Palm to finger ulnar sensory nerve conduction

    Directory of Open Access Journals (Sweden)

    Eduardo Davidowich

    2015-12-01

    Full Text Available Ulnar neuropathy at the wrist (UNW is rare, and always challenging to localize. To increase the sensitivity and specificity of the diagnosis of UNW many authors advocate the stimulation of the ulnar nerve (UN in the segment of the wrist and palm. The focus of this paper is to present a modified and simplified technique of sensory nerve conduction (SNC of the UN in the wrist and palm segments and demonstrate the validity of this technique in the study of five cases of type III UNW. The SNC of UN was performed antidromically with fifth finger ring recording electrodes. The UN was stimulated 14 cm proximal to the active electrode (the standard way and 7 cm proximal to the active electrode. The normal data from amplitude and conduction velocity (CV ratios between the palm to finger and wrist to finger segments were obtained. Normal amplitude ratio was 1.4 to 0.76. Normal CV ratio was 0.8 to 1.23.We found evidences of abnormal SNAP amplitude ratio or substantial slowing of UN sensory fibers across the wrist in 5 of the 5 patients with electrophysiological-definite type III UNW.

  7. Apple FLOWERING LOCUS T proteins interact with transcription factors implicated in cell growth and organ development.

    Science.gov (United States)

    Mimida, Naozumi; Kidou, Shin-Ichiro; Iwanami, Hiroshi; Moriya, Shigeki; Abe, Kazuyuki; Voogd, Charlotte; Varkonyi-Gasic, Erika; Kotoda, Nobuhiro

    2011-05-01

    Understanding the flowering process in apple (Malus × domestica Borkh.) is essential for developing methods to shorten the breeding period and regulate fruit yield. It is known that FLOWERING LOCUS T (FT) acts as a transmissible floral inducer in the Arabidopsis flowering network system. To clarify the molecular network of two apple FT orthologues, MdFT1 and MdFT2, we performed a yeast two-hybrid screen to identify proteins that interact with MdFT1. We identified several transcription factors, including two members of the TCP (TEOSINTE BRANCHED1, CYCLOIDEA and PROLIFERATING CELL FACTORs) family, designated MdTCP2 and MdTCP4, and an Arabidopsis thaliana VOZ1 (Vascular plant One Zinc finger protein1)-like protein, designated MdVOZ1. MdTCP2 and MdVOZ1 also interacted with MdFT2 in yeast. The expression domain of MdTCP2 and MdVOZ1 partially overlapped with that of MdFT1 and MdFT2, most strikingly in apple fruit tissue, further suggesting a potential interaction in vivo. Constitutive expression of MdTCP2, MdTCP4 and MdVOZ1 in Arabidopsis affected plant size, leaf morphology and the formation of leaf primordia on the adaxial side of cotyledons. On the other hand, chimeric MdTCP2, MdTCP4 and MdVOZ1 repressors that included the ethylene-responsive transcription factors (ERF)-associated amphiphilic repression (EAR) domain motif influenced reproduction and inflorescence architecture in transgenic Arabidopsis. These results suggest that MdFT1 and/or MdFT2 might be involved in the regulation of cellular proliferation and the formation of new tissues and that they might affect leaf and fruit development by interacting with TCP- and VOZ-family proteins. DDBJ accession nos. AB531019 (MdTCP2a mRNA), AB531020 (MdTCP2b mRNA), AB531021 (MdTCP4a mRNA), AB531022 (MdTCP4b mRNA) and AB531023 (MdVOZ1a mRNA). © The Author 2011. Published by Oxford University Press. All rights reserved.

  8. The Arabidopsis Transcription Factor ANAC032 Represses Anthocyanin Biosynthesis in Response to High Sucrose and Oxidative and Abiotic Stresses

    OpenAIRE

    Mahmood, Kashif; Xu, Zhenhua; El-Kereamy, Ashraf; Casaretto, Jos? A.; Rothstein, Steven J.

    2016-01-01

    Production of anthocyanins is one of the adaptive responses employed by plants during stress conditions. During stress, anthocyanin biosynthesis is mainly regulated at the transcriptional level via a complex interplay between activators and repressors of anthocyanin biosynthesis genes. In this study, we investigated the role of a NAC transcription factor, ANAC032, in the regulation of anthocyanin biosynthesis during stress conditions. ANAC032 expression was found to be induced by exogenous su...

  9. Aberrant REST-mediated transcriptional regulation in major depressive disorder.

    Science.gov (United States)

    Otsuki, Koji; Uchida, Shusaku; Wakabayashi, Yusuke; Matsubara, Toshio; Hobara, Teruyuki; Funato, Hiromasa; Watanabe, Yoshifumi

    2010-04-01

    There is growing evidence that aberrant transcriptional regulation is one of the key components of the pathophysiology of mood disorders. The repressor element-1 silencing transcription factor (REST) is a negative regulator of genes that contain the repressor element-1 (RE-1) binding site. REST has many target genes, including corticotropin releasing hormone (CRH), brain-derived neurotrophic factor, serotonin 1A receptor, which are suggested to be involved in the pathophysiology of depression and the action of antidepressants. However, a potential role for REST-mediated transcriptional regulation in mood disorders remains unclear. In this study, we examined the mRNA levels of REST and its known and putative target genes, using quantitative real-time PCR in peripheral blood cells of patients with major depressive and bipolar disorders in both a current depressive and a remissive state. We found reduced mRNA expression of REST and increased mRNA expression of CRH, adenylate cyclase 5, and the tumor necrosis factor superfamily, member 12-13 in patients with major depressive disorder in a current depressive state, but not in a remissive state. Altered expression of these mRNAs was not found in patients with bipolar disorder. Our results suggest that the aberrant REST-mediated transcriptional regulation of, at least, CRH, adenylate cyclase 5, and tumor necrosis factor superfamily, member 12-13, might be state-dependent and associated with the pathophysiology of major depression. Copyright 2009 Elsevier Ltd. All rights reserved.

  10. [Molecular cloning and expression analysis of a SUPERMAN-like zinc finger protein gene in upland cotton].

    Science.gov (United States)

    Yang, Yu-Wen; Ni, Wan-Chao; Zhang, Bao-Long; Shen, Xin-Lian; Zhang, Xiang-Gui; Xu, Ying-Jun; Yao, Shu

    2006-04-01

    The zinc finger proteins belong to the largest family of regulatory transcription factors, which play an important role in growth and development in animal and plant systems. SUPERMAN-like zinc finger protein gene has only one "finger like" motif. A pair of degenerate primers was designed according to the conserved regions, and 3 kinds of EST of this family were isolated from cotton through RT-PCR. The full length of one SUPERMAN-like zinc finger protein also has been acquired. The entire coding region is 744 bp and encodes a polypeptide of 248 amino acids with 40% homology to RBE protein of Arabidopsis deposited in the GenBank. This gene was designated as GZFP. It has the conserved zinc finger domain and the leucine rich region at the carboxyl terminus but no intron in the coding region. GZFP also has the plant nuclear localization signal. GZFP shows a more expression pattern in floral buds, ovaries, petals and roots than in phloem, xylem, fibers, leaves and seeds of cotton by RT-PCR, although it has a very low detection level and there is not any homologous ESTs found in the GenBank. Analysis of the 5' flanking sequence shows there are several regulatory elements responsible for pollen and root expression, four core sites required for binding of Dof proteins and four light-regulated elements.

  11. Genomic structure and cloning of two transcript isoforms of human Sp8.

    NARCIS (Netherlands)

    M.A. Milona (Maria-athina); J.E. Gough (Julie); A.J. Edgar (Alasdair)

    2004-01-01

    textabstractBACKGROUND: The Specificity proteins (Sp) are a family of transcription factors that have three highly conserved zinc-fingers located towards the carboxy-terminal that bind GC-boxes and assist in the initiation of gene transcription. Human Sp1-7 genes have been

  12. ChIP-Seq Data Analysis to Define Transcriptional Regulatory Networks.

    Science.gov (United States)

    Pavesi, Giulio

    The first step in the definition of transcriptional regulatory networks is to establish correct relationships between transcription factors (TFs) and their target genes, together with the effect of their regulatory activity (activator or repressor). Fundamental advances in this direction have been made possible by the introduction of experimental techniques such as Chromatin Immunoprecipitation, which, coupled with next-generation sequencing technologies (ChIP-Seq), permit the genome-wide identification of TF binding sites. This chapter provides a survey on how data of this kind are to be processed and integrated with expression and other types of data to infer transcriptional regulatory rules and codes.

  13. The role of fingers in number processing in young children

    Directory of Open Access Journals (Sweden)

    Anne eLafay

    2013-07-01

    Full Text Available The aim of the present study was to investigate the relationship between finger counting and numerical processing in 4- to 7-year-old children. Children were assessed on a variety of numerical tasks and we examined the correlations between their rates of success and their frequency of finger use in a counting task. We showed that children’s performance on finger pattern comparison and identification tasks did not correlate with the frequency of finger use. However, this last variable correlated with the percentages of correct responses in an enumeration task (i.e., Give-N task, even when the age of children was entered as a covariate in the analysis. Despite this correlation, we showed that some children who never used their fingers in the counting task were able to perform optimally in the enumeration task. Overall, our results support the conclusion that finger counting is useful but not necessary to develop accurate symbolic numerical skills. Moreover, our results suggest that the use of fingers in a counting task is related to the ability of children in a dynamic enumeration task but not to static tasks involving recognition or comparison of finger patterns. Therefore, it could be that the link between fingers and numbers remain circumscribed to counting tasks and do not extent to static finger montring situations.

  14. The role of fingers in number processing in young children.

    Science.gov (United States)

    Lafay, Anne; Thevenot, Catherine; Castel, Caroline; Fayol, Michel

    2013-01-01

    The aim of the present study was to investigate the relationship between finger counting and numerical processing in 4-7-year-old children. Children were assessed on a variety of numerical tasks and we examined the correlations between their rates of success and their frequency of finger use in a counting task. We showed that children's performance on finger pattern comparison and identification tasks did not correlate with the frequency of finger use. However, this last variable correlated with the percentages of correct responses in an enumeration task (i.e., Give-N task), even when the age of children was entered as a covariate in the analysis. Despite this correlation, we showed that some children who never used their fingers in the counting task were able to perform optimally in the enumeration task. Overall, our results support the conclusion that finger counting is useful but not necessary to develop accurate symbolic numerical skills. Moreover, our results suggest that the use of fingers in a counting task is related to the ability of children in a dynamic enumeration task but not to static tasks involving recognition or comparison of finger patterns. Therefore, it could be that the link between fingers and numbers remain circumscribed to counting tasks and do not extent to static finger montring situations.

  15. Speed invariance of independent control of finger movements in pianists

    Science.gov (United States)

    Soechting, John F.

    2012-01-01

    Independent control of finger movements characterizes skilled motor behaviors such as tool use and musical performance. The purpose of the present study was to identify the effect of movement frequency (tempo) on individuated finger movements in piano playing. Joint motion at the digits was recorded while 5 expert pianists were playing 30 excerpts from musical pieces with different fingering and key locations either at a predetermined normal tempo or as fast as possible. Principal component analysis and cluster analysis using an expectation-maximization algorithm determined three distinct patterns of finger movement coordination for a keypress with each of the index, middle, ring, and little fingers at each of the two tempi. The finger kinematics of each coordination pattern was overall similar across the tempi. Tone sequences assigned into each cluster were also similar for both tempi. A linear regression analysis determined no apparent difference in the amount of movement covariation between the striking and nonstriking fingers at both metacarpo-phalangeal and proximal-interphalangeal joints across the two tempi, which indicated no effect of tempo on independent finger movements in piano playing. In addition, the standard deviation of interkeystroke interval across strokes did not differ between the two tempi, indicating maintenance of rhythmic accuracy of keystrokes. Strong temporal constraints on finger movements during piano playing may underlie the maintained independent control of fingers over a wider range of tempi, a feature being likely to be specific to skilled pianists. PMID:22815403

  16. The Role of Vision in the Development of Finger-Number Interactions: Finger-Counting and Finger-Montring in Blind Children

    Science.gov (United States)

    Crollen, Virginie; Mahe, Rachel; Collignon, Olivier; Seron, Xavier

    2011-01-01

    Previous research has suggested that the use of the fingers may play a functional role in the development of a mature counting system. However, the role of developmental vision in the elaboration of a finger numeral representation remains unexplored. In the current study, 14 congenitally blind children and 14 matched sighted controls undertook…

  17. Lac repressor: Crystallization of intact tetramer and its complexes with inducer and operator DNA

    International Nuclear Information System (INIS)

    Pace, H.C.; Lu, P.; Lewis, M.

    1990-01-01

    The intact lac repressor tetramer, which regulates expression of the lac operon in Escherichia coli, has been crystallized in the native form, with an inducer, and in a ternary complex with operator DNA and an anti-inducer. The crystals without DNA diffract to better than 3.5 angstrom. They belong to the monoclinic space group C2 and have cell dimensions a = 164.7 angstrom, b = 75.6 angstrom, and c = 161.2 angstrom, with α = γ = 90 degree and β = 125.5 degree. Cocrystals have been obtained with a number of different lac operator-related DNA fragments. The complex with a blunt-ended 16-base-pair strand yielded tetragonal bipyramids that diffract to 6.5 angstrom. These protein-DNA cocrystals crack upon exposure to the gratuitous inducer isopropyl β-D-thiogalactoside, suggesting a conformational change in the repressor-operator complex

  18. Hydrogen exchange in hydrated films of proteins. Application to the E. coli lac repressor core

    International Nuclear Information System (INIS)

    Pilet, J.; Szabo, A.G.; Maurizot, J.-C.

    1980-01-01

    An original easy method of hydrogen to deuterium exchange in hydrated films of proteins, followed by infrared absorption measurements, is described and applied to films of the E. coli lac repressor core, in order to examine the effect of isopropyl-β-D-thiogalactoside (IPTG) binding. An estimation of about 25% α helical structure in this protein fragment is deduced from the exchange curve. The binding of IPTG to the core does not affect the exchange curve within the experimental error limits. (Auth.)

  19. Modular organisation of inducer recognition and allostery in the tetracycline repressor.

    Science.gov (United States)

    Werten, Sebastiaan; Schneider, Julia; Palm, Gottfried Julius; Hinrichs, Winfried

    2016-06-01

    Induction of the tetracycline repressor (TetR) results from antibiotic-dependent changes in the relative positioning of the DNA-binding domains within the promoter-associated repressor dimer, but the key determinants of this allosteric effect remain poorly characterised. Intriguingly, previous mutational analyses of the tetracycline-interacting site revealed a lack of correlation between residual affinity and induction propensity, suggesting that some of the residues in contact with the antibiotic primarily act in ligand recognition and retention, whereas others are required to transmit the allosteric signal. Here, we provide a structural basis for these observations via crystallographic analysis of the point mutants N82A, H100A, T103A and E147A in complex with the inducer 5a,6-anhydrotetracycline. In conjunction with the available functional data, the four structures demonstrate that a trigger-like movement of the region between helices α6 and α7 towards and into the binding site plays a decisive role in the intramolecular communication process. In sharp contrast, residues lining the binding cavity proper have little or no influence on the allosteric mechanism as such. This nearly complete physical separation of ligand recognition and allostery will have allowed diverging TetR-like repressors to bind novel effectors while the existing induction mechanism remained intact. Consequently, the modularity described here may have been a key factor in the evolutionary success of the widespread and highly diversified repressor class. Structural data are available in the Protein Data Bank under the accession numbers 5FKK, 5FKL, 5FKM, 5FKN and 5FKO. © 2016 Federation of European Biochemical Societies.

  20. Histone deacetylase inhibitor trichostatin A enhances myogenesis by coordinating muscle regulatory factors and myogenic repressors

    Energy Technology Data Exchange (ETDEWEB)

    Hagiwara, Hiroki [Department of Neurology, Teikyo University School of Medicine, 2-11-1 Kaga, Itabashi-ku, Tokyo 173-8605 (Japan); Department of Medical Science, Teikyo University of Science, 2-2-1 Senjusakuragi, Adachi-ku, Tokyo 120-0045 (Japan); Saito, Fumiaki, E-mail: f-saito@med.teikyo-u.ac.jp [Department of Neurology, Teikyo University School of Medicine, 2-11-1 Kaga, Itabashi-ku, Tokyo 173-8605 (Japan); Masaki, Toshihiro [Department of Neurology, Teikyo University School of Medicine, 2-11-1 Kaga, Itabashi-ku, Tokyo 173-8605 (Japan); Department of Medical Science, Teikyo University of Science, 2-2-1 Senjusakuragi, Adachi-ku, Tokyo 120-0045 (Japan); Ikeda, Miki; Nakamura-Ohkuma, Ayami; Shimizu, Teruo; Matsumura, Kiichiro [Department of Neurology, Teikyo University School of Medicine, 2-11-1 Kaga, Itabashi-ku, Tokyo 173-8605 (Japan)

    2011-11-04

    Highlights: Black-Right-Pointing-Pointer We investigated the effect of TSA, one of most potent HDACIs, on myogenesis using the C2C12 skeletal muscle cell line. Black-Right-Pointing-Pointer TSA enhances the expression of myosin heavy chain without affecting DAPC expression. Black-Right-Pointing-Pointer TSA enhances the expression of the early MRFs, Myf5 and MEF2, and suppresses the late MRF, myogenin, after 24 h treatment. Black-Right-Pointing-Pointer TSA enhances the expression of the myogenic repressors, Ids, which inhibit myogenic differentiation. Black-Right-Pointing-Pointer TSA promotes myogenesis by coordinating the expression of MRFs and myogenic repressors. -- Abstract: Histone deacetylase inhibitors (HDACIs) are known to promote skeletal muscle formation. However, their mechanisms that include effects on the expression of major muscle components such as the dystrophin-associated proteins complex (DAPC) or myogenic regulatory factors (MRFs) remain unknown. In this study, we investigated the effects of HDACIs on skeletal muscle formation using the C2C12 cell culture system. C2C12 myoblasts were exposed to trichostatin A (TSA), one of the most potent HDACIs, and differentiation was subsequently induced. We found that TSA enhances the expression of myosin heavy chain without affecting DAPC expression. In addition, TSA increases the expression of the early MRFs, Myf5 and MEF2, whereas it suppresses the expression of the late MRF, myogenin. Interestingly, TSA also enhances the expression of Id1, Id2, and Id3 (Ids). Ids are myogenic repressors that inhibit myogenic differentiation. These findings suggest that TSA promotes gene expression in proliferation and suppresses it in the differentiation stage of muscle formation. Taken together, our data demonstrate that TSA enhances myogenesis by coordinating the expression of MRFs and myogenic repressors.

  1. Torque Control of Underactuated Tendon-driven Robotic Fingers

    Science.gov (United States)

    Abdallah, Muhammad E. (Inventor); Ihrke, Chris A. (Inventor); Reiland, Matthew J. (Inventor); Wampler, Charles W. (Inventor); Diftler, Myron A. (Inventor); Platt, Robert (Inventor); Bridgwater, Lyndon (Inventor)

    2013-01-01

    A robotic system includes a robot having a total number of degrees of freedom (DOF) equal to at least n, an underactuated tendon-driven finger driven by n tendons and n DOF, the finger having at least two joints, being characterized by an asymmetrical joint radius in one embodiment. A controller is in communication with the robot, and controls actuation of the tendon-driven finger using force control. Operating the finger with force control on the tendons, rather than position control, eliminates the unconstrained slack-space that would have otherwise existed. The controller may utilize the asymmetrical joint radii to independently command joint torques. A method of controlling the finger includes commanding either independent or parameterized joint torques to the controller to actuate the fingers via force control on the tendons.

  2. A Novel Prokaryotic Green Fluorescent Protein Expression System for Testing Gene Editing Tools Activity Like Zinc Finger Nuclease

    OpenAIRE

    Sabzehei, Faezeh; Kouhpayeh, Shirin; Dastjerdeh, Mansoureh Shahbazi; Khanahmad, Hossein; Salehi, Rasoul; Naderi, Shamsi; Taghizadeh, Razieh; Rabiei, Parisa; Hejazi, Zahra; Shariati, Laleh

    2017-01-01

    Background: Gene editing technology has created a revolution in the field of genome editing. The three of the most famous tools in gene editing technology are zinc finger nucleases (ZFNs), transcription activator-like effector nucleases, clustered regularly interspaced short palindromic repeats (CRISPR), and CRISPR-associated systems. As their predictable nature, it is necessary to assess their efficiency. There are some methods for this purpose, but most of them are time labor and complicate...

  3. Aspergillus Sydowi Infection of Human Finger Nail

    Directory of Open Access Journals (Sweden)

    A K Barde

    1981-01-01

    Full Text Available A case of Aspergillus sydowi infection of left middle finger nail is described ′ The presence of fungal hypae with phialids and spores on direct microscopy as well as in culture, the colour of the sub-ungual mass of the nail resembling the colour of the fungus in, culture′ repeated isolations of A sydowi from the diseased tissue along with the absence of any established pathogenic species in the specimen are taken as evidences that this fungus was invading the nail tissue.

  4. Finger Injuries in Football and Rugby.

    Science.gov (United States)

    Elzinga, Kate E; Chung, Kevin C

    2017-02-01

    Football and rugby athletes are at increased risk of finger injuries given the full-contact nature of these sports. Some players may return to play early with protective taping, splinting, and casting. Others require a longer rehabilitation period and prolonged time away from the field. The treating hand surgeon must weigh the benefits of early return to play for the current season and future playing career against the risks of reinjury and long-term morbidity, including post-traumatic arthritis and decreased range of motion and strength. Each player must be comprehensively assessed and managed with an individualized treatment plan. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Finger Clubbing Caused by Herbal Tea

    Directory of Open Access Journals (Sweden)

    Saifudin Rashiq

    1996-01-01

    Full Text Available Clubbing of the fingers is often taken to be a sign of serious illness. Its discovery, particularly if there are associated symptoms in the cardiovascular, respiratory or gastrointestinal systems, usually leads to exhaustive investigation. A case is presented in which the etiology of clubbing was found only when a new history of heavy ingestion of herbal tea was obtained, extensive work-up having previously been unhelpful. Other cases appearing in the English-language literature are cited, some universal etiological associations are described, and an attempt is made to explain the phenomenon, based on a recent theory of the cause of clubbing.

  6. Genome editing with engineered zinc finger nucleases.

    Science.gov (United States)

    Urnov, Fyodor D; Rebar, Edward J; Holmes, Michael C; Zhang, H Steve; Gregory, Philip D

    2010-09-01

    Reverse genetics in model organisms such as Drosophila melanogaster, Arabidopsis thaliana, zebrafish and rats, efficient genome engineering in human embryonic stem and induced pluripotent stem cells, targeted integration in crop plants, and HIV resistance in immune cells - this broad range of outcomes has resulted from the application of the same core technology: targeted genome cleavage by engineered, sequence-specific zinc finger nucleases followed by gene modification during subsequent repair. Such 'genome editing' is now established in human cells and a number of model organisms, thus opening the door to a range of new experimental and therapeutic possibilities.

  7. Structural and functional organization of the HF.10 human zinc finger gene (ZNF35) located on chromosome 3p21-p22

    DEFF Research Database (Denmark)

    Lanfrancone, L; Pengue, G; Pandolfi, P P

    1992-01-01

    the last 3' exon. The genomic region surrounding HF.10 exon 1 contains a CpG island and acts as a promoter in vitro. Using transient CAT assay in cotransfection experiments in cultured cells, we have determined that the HF.10 finger protein is a transcriptional transactivator. Restriction enzyme mapping...

  8. Discrimination of Finger Area of Somatosensory Cortex by NIRS

    Science.gov (United States)

    Xu, Mingdi; Hayami, Takehito; Iramina, Keiji

    We carried out a near-infrared spectroscopy (NIRS) study to observe the hemodynamic responses associated with cortical activation in the primary somatosensory cortex (SI) by finger electrical stimulation. We examined whether NIRS can assist in investigating the somatotopic arrangement of fingers on the SI hand area. We found that although relatively low in spatial resolution, NIRS can to some extent help to discriminate the representations of thumb and ring finger on the SI hand area.

  9. Sensing DNA damage by PARP-like fingers

    OpenAIRE

    Petrucco, Stefania

    2003-01-01

    PARP-like zinc fingers are protein modules, initially described as nick-sensors of poly(ADP-ribosyl)-polymerases (PARPs), which are found at the N-terminus of different DNA repair enzymes. I chose to study the role of PARP-like fingers in AtZDP, a 3′ DNA phosphoesterase, which is the only known enzyme provided with three such finger domains. Here I show that PARP-like fingers can maintain AtZDP onto damaged DNA sites without interfering with its DNA end repair functions. Damage recognition by...

  10. Tetanus following replantation of an amputated finger: a case report.

    Science.gov (United States)

    Hayashida, Kenji; Murakami, Chikako; Fujioka, Masaki

    2012-10-08

    Tetanus is an infectious disease caused by tetanus toxin produced by Clostridium tetani and induces severe neurological manifestations. We treated a patient who developed tetanus during hospitalization for replantation of an amputated finger. To the best of our knowledge, this is the first published case report of such an entity. A 49-year-old Japanese man had an amputation of his right middle finger at the distal interphalangeal joint region in an accident at work. His middle finger was successfully replanted, but his fingertip was partially necrotized because of crushing and so additional reconstruction with a reverse digital arterial flap was performed 15 days after the injury. Tetanus developed 21 days after replantation of the middle finger, but symptoms remitted via rapid diagnosis and treatment. In replantation after finger trauma with exposure of nerve and blood vessel bundles, concern over injuring nerves and blood vessels may prevent irrigation and debridement from being performed sufficiently; these treatments may have been insufficiently performed in this patient. It is likely that the replanted middle finger partially adhered, and Clostridium tetani colonized the partially necrotized region. Even when there is only limited soil contamination, administration of tetanus toxoid and anti-tetanus immunoglobulin is necessary when the fingers are injured outdoors and the finger nerves and blood vessels are exposed. The drugs should be administered just after replantation if the finger has been amputated. However, if clinicians pay attention to the possibility of tetanus development, treatment can be rapidly initiated.

  11. Tetanus following replantation of an amputated finger: a case report

    Directory of Open Access Journals (Sweden)

    Hayashida Kenji

    2012-10-01

    Full Text Available Abstract Introduction Tetanus is an infectious disease caused by tetanus toxin produced by Clostridium tetani and induces severe neurological manifestations. We treated a patient who developed tetanus during hospitalization for replantation of an amputated finger. To the best of our knowledge, this is the first published case report of such an entity. Case presentation A 49-year-old Japanese man had an amputation of his right middle finger at the distal interphalangeal joint region in an accident at work. His middle finger was successfully replanted, but his fingertip was partially necrotized because of crushing and so additional reconstruction with a reverse digital arterial flap was performed 15 days after the injury. Tetanus developed 21 days after replantation of the middle finger, but symptoms remitted via rapid diagnosis and treatment. Conclusions In replantation after finger trauma with exposure of nerve and blood vessel bundles, concern over injuring nerves and blood vessels may prevent irrigation and debridement from being performed sufficiently; these treatments may have been insufficiently performed in this patient. It is likely that the replanted middle finger partially adhered, and Clostridium tetani colonized the partially necrotized region. Even when there is only limited soil contamination, administration of tetanus toxoid and anti-tetanus immunoglobulin is necessary when the fingers are injured outdoors and the finger nerves and blood vessels are exposed. The drugs should be administered just after replantation if the finger has been amputated. However, if clinicians pay attention to the possibility of tetanus development, treatment can be rapidly initiated.

  12. Identification and characterization of small molecule inhibitors of a PHD finger§

    Science.gov (United States)

    Wagner, Elise K.; Nath, Nidhi; Flemming, Rod; Feltenberger, John B.; Denu, John M.

    2012-01-01

    A number of histone-binding domains are implicated in cancer through improper binding of chromatin. In a clinically reported case of acute myeloid leukemia (AML), a genetic fusion protein between nucleoporin 98 and the third plant homeodomain (PHD) finger of JARID1A drives an oncogenic transcriptional program that is dependent on histone binding by the PHD finger. By exploiting the requirement for chromatin binding in oncogenesis, therapeutics targeting histone readers may represent a new paradigm in drug development. In this study, we developed a novel small molecule screening strategy that utilizes HaloTag technology to identify several small molecules that disrupt binding of the JARID1A PHD finger to histone peptides. Small molecule inhibitors were validated biochemically through affinity pull downs, fluorescence polarization, and histone reader specificity studies. One compound was modified through medicinal chemistry to improve its potency while retaining histone reader selectivity. Molecular modeling and site-directed mutagenesis of JARID1A PHD3 provided insights into the biochemical basis of competitive inhibition. PMID:22994852

  13. Identifying key interactions stabilizing DOF zinc finger-DNA complexes using in silico approaches.

    Science.gov (United States)

    Hamzeh-Mivehroud, Maryam; Moghaddas-Sani, Hakimeh; Rahbar-Shahrouziasl, Mahdieh; Dastmalchi, Siavoush

    2015-10-07

    DOF (DNA-binding with one finger) proteins, a family of DNA-binding transcription factors, are members of zinc fingers unique to plants. They are associated with different plant specific phenomena including germination, dormancy, light and defense responses. Until now, there is no report of experimentally solved structure for DOF proteins, making empirical investigation of DOF-DNA interaction more challenging. It has been shown that comparative modeling can be used to reliably predict the three-dimensional (3D) model of structurally unknown proteins whenever a suitable template is available. Furthermore, current molecular mechanics force fields allow prediction of interaction energies for macromolecular complexes. Therefore, the approaches considered in this work were to model the 3D structures of DOF zinc fingers (ZFs) from Arabidopsis thaliana complexed with DNA molecule, to calculate their binding energies, to identify key interactions established between ZFs and DNA, and to determine the impact of the different interactions on the binding energies. The results were used to predict the binding affinities for the novel designed ZFs and may be used in engineering DNA binding proteins. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Symmetric allosteric mechanism of hexameric Escherichia coli arginine repressor exploits competition between L-arginine ligands and resident arginine residues.

    Directory of Open Access Journals (Sweden)

    Rebecca Strawn

    2010-06-01

    Full Text Available An elegantly simple and probably ancient molecular mechanism of allostery is described for the Escherichia coli arginine repressor ArgR, the master feedback regulator of transcription in L-arginine metabolism. Molecular dynamics simulations with ArgRC, the hexameric domain that binds L-arginine with negative cooperativity, reveal that conserved arginine and aspartate residues in each ligand-binding pocket promote rotational oscillation of apoArgRC trimers by engagement and release of hydrogen-bonded salt bridges. Binding of exogenous L-arginine displaces resident arginine residues and arrests oscillation, shifting the equilibrium quaternary ensemble and promoting motions that maintain the configurational entropy of the system. A single L-arg ligand is necessary and sufficient to arrest oscillation, and enables formation of a cooperative hydrogen-bond network at the subunit interface. The results are used to construct a free-energy reaction coordinate that accounts for the negative cooperativity and distinctive thermodynamic signature of L-arginine binding detected by calorimetry. The symmetry of the hexamer is maintained as each ligand binds, despite the conceptual asymmetry of partially-liganded states. The results thus offer the first opportunity to describe in structural and thermodynamic terms the symmetric relaxed state predicted by the concerted allostery model of Monod, Wyman, and Changeux, revealing that this state is achieved by exploiting the dynamics of the assembly and the distributed nature of its cohesive free energy. The ArgR example reveals that symmetry can be maintained even when binding sites fill sequentially due to negative cooperativity, which was not anticipated by the Monod, Wyman, and Changeux model. The molecular mechanism identified here neither specifies nor requires a pathway for transmission of the allosteric signal through the protein, and it suggests the possibility that binding of free amino acids was an early

  15. Novel repressor of Escherichia coli O157:H7 motility encoded in the putative fimbrial cluster OI-1.

    Science.gov (United States)

    Allison, Sarah E; Silphaduang, Uma; Mascarenhas, Mariola; Konczy, Paulina; Quan, Quyen; Karmali, Mohamed; Coombes, Brian K

    2012-10-01

    Escherichia coli O157:H7 is a gastrointestinal pathogen that has become a serious public health concern, as it is associated with outbreaks and severe diseases such as hemolytic-uremic syndrome. The molecular basis of its greater virulence than that of other serotypes is not completely known. OI-1 is a putative fimbria-encoding genomic island that is found almost exclusively in O157:H7 Shiga toxin-producing E. coli strains and may be associated with the enhanced pathogenesis of these strains. In this study, we identified and characterized a novel repressor of flagellar synthesis encoded by OI-1. We showed that deletion of Z0021 increased the motility of E. coli O157:H7, which correlated with an increase in flagellin production and enhanced assembly of flagella on the cell surface. In contrast, overexpression of Z0021 inhibited motility. We demonstrated that Z0021 exerted its regulatory effects downstream of the transcription and translation of flhDC but prior to the activation of class II/III promoters. Furthermore, the master regulator of flagellar synthesis, FlhD(4)C(2), was shown to be a high-copy suppressor of the nonmotile phenotype associated with elevated levels of Z0021--a finding consistent with Z0021-FlhD(4)C(2) being a potential regulatory complex. This work provides insight into the mechanism by which Z0021, which we have named fmrA, represses flagellar synthesis and is the first report of a fimbrial-operon-encoded inhibitor of motility in E. coli O157:H7.

  16. The RpiR-Like Repressor IolR Regulates Inositol Catabolism in Sinorhizobium meliloti▿†

    Science.gov (United States)

    Kohler, Petra R. A.; Choong, Ee-Leng; Rossbach, Silvia

    2011-01-01

    Sinorhizobium meliloti, the nitrogen-fixing symbiont of alfalfa, has the ability to catabolize myo-, scyllo-, and d-chiro-inositol. Functional inositol catabolism (iol) genes are required for growth on these inositol isomers, and they play a role during plant-bacterium interactions. The inositol catabolism genes comprise the chromosomally encoded iolA (mmsA) and the iolY(smc01163)RCDEB genes, as well as the idhA gene located on the pSymB plasmid. Reverse transcriptase assays showed that the iolYRCDEB genes are transcribed as one operon. The iol genes were weakly expressed without induction, but their expression was strongly induced by myo-inositol. The putative transcriptional regulator of the iol genes, IolR, belongs to the RpiR-like repressor family. Electrophoretic mobility shift assays demonstrated that IolR recognized a conserved palindromic sequence (5′-GGAA-N6-TTCC-3′) in the upstream regions of the idhA, iolY, iolR, and iolC genes. Complementation assays found IolR to be required for the repression of its own gene and for the downregulation of the idhA-encoded myo-inositol dehydrogenase activity in the presence and absence of inositol. Further expression studies indicated that the late pathway intermediate 2-keto-5-deoxy-d-gluconic acid 6-phosphate (KDGP) functions as the true inducer of the iol genes. The iolA (mmsA) gene encoding methylmalonate semialdehyde dehydrogenase was not regulated by IolR. The S. meliloti iolA (mmsA) gene product seems to be involved in more than only the inositol catabolic pathway, since it was also found to be essential for valine catabolism, supporting its more recent annotation as mmsA. PMID:21784930

  17. Evaluation of novel inducible promoter/repressor systems for recombinant protein expression in Lactobacillus plantarum.

    Science.gov (United States)

    Heiss, Silvia; Hörmann, Angelika; Tauer, Christopher; Sonnleitner, Margot; Egger, Esther; Grabherr, Reingard; Heinl, Stefan

    2016-03-10

    Engineering lactic acid bacteria (LAB) is of growing importance for food and feed industry as well as for in vivo vaccination or the production of recombinant proteins in food grade organisms. Often, expression of a transgene is only desired at a certain time point or period, e.g. to minimize the metabolic burden for the host cell or to control the expression time span. For this purpose, inducible expression systems are preferred, though cost and availability of the inducing agent must be feasible. We selected the plasmid free strain Lactobacillus plantarum 3NSH for testing and characterization of novel inducible promoters/repressor systems. Their feasibility in recombinant protein production was evaluated. Expression of the reporter protein mCherry was monitored with the BioLector(®) micro-fermentation system. Reporter gene mCherry expression was compared under the control of different promoter/repressor systems: PlacA (an endogenous promoter/repressor system derived from L. plantarum 3NSH), PxylA (a promoter/repressor system derived from Bacillus megaterium DSMZ 319) and PlacSynth (synthetic promoter and codon-optimized repressor gene based on the Escherichia coli lac operon). We observed that PlacA was inducible solely by lactose, but not by non-metabolizable allolactose analoga. PxylA was inducible by xylose, yet showed basal expression under non-induced conditions. Growth on galactose (as compared to exponential growth phase on glucose) reduced basal mCherry expression at non-induced conditions. PlacSynth was inducible with TMG (methyl β-D-thiogalactopyranoside) and IPTG (isopropyl β-D-1-thiogalactopyranoside), but also showed basal expression without inducer. The promoter PlacSynth was used for establishment of a dual plasmid expression system, based on T7 RNA polymerase driven expression in L. plantarum. Comparative Western blot supported BioLector(®) micro-fermentation measurements. Conclusively, overall expression levels were moderate (compared to a

  18. Cholinergic vasodilator mechanism in human fingers

    Energy Technology Data Exchange (ETDEWEB)

    Coffman, J.D.; Cohen, R.A.

    1987-03-01

    The effect of a cholinergic agonist and antagonist on finger blood flow (FBF) was studied in 10 normal subjects. Total finger blood flow was measured by venous occlusion, air plethysmography, and capillary blood flow (FCF) by the disappearance rate of a radio-isotope from a fingertip injection. Methacholine in doses of 10-80 ..mu..g/min was given by constant infusion via a brachial artery catheter. Average FBF and vascular resistance were not significantly affected. However, the half time (t/sub 1/2/) of the disappearance rate decreased from 50.8 +/- 13.4 to 11.1 +/- 1.5 min; a decrease occurred in all subjects. In seven subjects, atropine (0.2 mg) had no affect alone but inhibited the effect of methacholine on FCF and prevented the redness and sweating of the forearm and hand that occurs with this agent. This study demonstrates a muscarinic cholinergic vasodilator mechanism in the fingertip that uniquely increase capillary blood flow.

  19. Dermatoglyphic patterns on fingers and gynecological cancers.

    Science.gov (United States)

    Abbasi, Sakineh; Rasouli, Mina

    2018-03-01

    Fingerprints have so far been used for determining the basis of certain malignant diseases, with positive outcomes. Considering the high rates of cancer-related mortality in Iran, this study was conducted for the purpose of examining the dermatoglyphic pattern of fingers in patients with gynecological cancers as compared to healthy people. The present study was conducted on 151 women with gynecological cancers as the case group and 152 healthy women with no history of such cancers as control group. The dematographic details of participants from both control and case groups were collected using a checklist, and the pattern of their fingerprints was prepared and examined. The data were analyzed for their significance using chi-square test and t- test. Odds ratio with 95% confidence intervals were calculated. Dermatoglyphic analysis showed that arch and loop patterns significantly changed in cases group as compared to control. However, the odds ratio suggested that loop pattern in 6 or more fingers might be a risk factor for developing gynecological cancers. Our results showed that there is an association between fingerprint patterns and gynecological cancers and so, dermatoglyphic analysis may aid in the early diagnosis of these cancers. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Oxidation-Mediated Fingering in Liquid Metals

    Science.gov (United States)

    Eaker, Collin B.; Hight, David C.; O'Regan, John D.; Dickey, Michael D.; Daniels, Karen E.

    2017-10-01

    We identify and characterize a new class of fingering instabilities in liquid metals; these instabilities are unexpected due to the large interfacial tension of metals. Electrochemical oxidation lowers the effective interfacial tension of a gallium-based liquid metal alloy to values approaching zero, thereby inducing drastic shape changes, including the formation of fractals. The measured fractal dimension (D =1.3 ±0.05 ) places the instability in a different universality class than other fingering instabilities. By characterizing changes in morphology and dynamics as a function of droplet volume and applied electric potential, we identify the three main forces involved in this process: interfacial tension, gravity, and oxidative stress. Importantly, we find that electrochemical oxidation can generate compressive interfacial forces that oppose the tensile forces at a liquid interface. The surface oxide layer ultimately provides a physical and electrochemical barrier that halts the instabilities at larger positive potentials. Controlling the competition between interfacial tension and oxidative (compressive) stresses at the interface is important for the development of reconfigurable electronic, electromagnetic, and optical devices that take advantage of the metallic properties of liquid metals.

  1. Possible effect of SNAIL family transcriptional repressor 1 polymorphisms in non-syndromic cleft lip with or without cleft palate.

    Science.gov (United States)

    Cura, Francesca; Palmieri, Annalisa; Girardi, Ambra; Carinci, Francesco; Morselli, Paolo Giovanni; Nouri, Nayereh; Pezzetti, Furio; Scapoli, Luca; Martinelli, Marcella

    2018-01-27

    Orofacial development is a complex process subjected to failure impairing. Indeed, the cleft of the lip and/or of the palate is among the most frequent inborn malformations. The JARID2 gene has been suggested to be involved in non-syndromic cleft lip with or without cleft palate (nsCL/P) etiology. JARID2 interacts with the polycomb repressive complex 2 (PRC2) in regulating the expression patterns of developmental genes by modifying the chromatin state. Genes coding for the PRC2 components, as well as other genes active in cell differentiation and embryonic development, were selected for a family-based association study to verify their involvement in nsCL/P. A total of 632 families from Italy and Asia participated to the study. Evidence of allelic association was found with polymorphisms of SNAI1; in particular, the rs16995010-G allele was undertransmitted to the nsCL/P cases [P = 0.004, odds ratio = 0.69 (95% C.I. 0.54-0.89)]. However, the adjusted significance value corrected for all the performed tests was P = 0.051. The findings emerging by the present study suggest for the first time an involvement of SNAI1 in the nsCL/P onset. Interestingly, SNAI1 is known to promote epithelial to mesenchymal transition by repressing E-cadherin expression, but it needs an intact PRC2 to act this function. Alterations of this process could contribute to the complex etiology of nsCL/P.

  2. Differential modulation of androgen receptor transcriptional activity by the nuclear receptor co-repressor (N-CoR).

    NARCIS (Netherlands)

    C.A. Berrevoets (Cor); A. Umar (Arzu); A.O. Brinkmann (Albert); J. Trapman (Jan)

    2004-01-01

    textabstractAntiandrogens are widely used agents in the treatment of prostate cancer, as inhibitors of AR (androgen receptor) action. Although the precise mechanism of antiandrogen action is not yet elucidated, recent studies indicate the involvement of nuclear receptor

  3. Osteogenic differentiation of mouse mesenchymal progenitor cell, Kusa-A1 is promoted by mammalian transcriptional repressor Rbpj

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shengchao [Department of Preventive Dentistry, School of Stomatology, The Fourth Military Medical University, 145 West Changle Road, 710032 Xi' an (China); Kawashima, Nobuyuki, E-mail: kawashima.n.endo@tmd.ac.jp [Department of Pulp Biology and Endodontics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549 (Japan); Sakamoto, Kei; Katsube, Ken-ichi [Department of Oral Pathology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549 (Japan); Umezawa, Akihiro [Department of Reproductive Biology and Pathology, National Institute for Child Health and Development, 2-10-4 Ohkura, Setagaya-ku, Tokyo 157-8535 (Japan); Suda, Hideaki [Department of Pulp Biology and Endodontics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549 (Japan); GCOE Program, International Research Center for Molecular Science in Tooth and Bone Diseases, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549 (Japan)

    2010-09-10

    Research highlights: {yields} High Rbpj mRNA expression was observed in mesenchymal cells surrounding the bone of mouse embryos. {yields} Overexpression of Rbpj depressed Notch-Hes1/Hey1 signaling. {yields} Rbpj upregulated promoter activities of Runx2 and Ose2. {yields} Rbpj promoted osteoblastic differentiation/maturation in Kusa-A1 cells. -- Abstract: Pluripotent mesenchymal stem cells possess the ability to differentiate into many cell types, but the precise mechanisms of differentiation are still unclear. Here, we provide evidence that Rbpj (recombination signal-binding protein for immunoglobulin kappa j region) protein, the primary nuclear mediator of Notch, is involved in osteogenesis. Overexpression of Rbpj promoted osteogenic differentiation of mouse Kusa-A1 cells in vitro and in vivo. Transient transfection of an Rbpj expression vector into Kusa-A1 cells upregulated promoter activities of Runx2 and Ose2. Enhanced osteogenic potentials including high alkaline phosphatase activity, rapid calcium deposition, and increased calcified nodule formation, were observed in established stable Rbpj-overexpressing Kusa-A1 (Kusa-A1/Rbpj) cell line. In vivo mineralization by Kusa-A1/Rbpj was promoted compared to that by Kusa-A1 host cells. Histological findings revealed that expression of Rbpj was primarily observed in osteoblasts. These results suggest that Rbpj may play essential roles in osteoblast differentiation.

  4. The transcriptional repressor Zbtb20 is essential for specification of hippocampal projection neurons and territory in mice

    DEFF Research Database (Denmark)

    Rosenthal, Eva Helga

    for specification of both hippocampal pyramidal neurons and territory in a mouse knockout model. Homozygous Zbtb20-/- mice are viable at birth, but display dwarfism and die during the first month of postnatal life. Characterization of the Zbtb20-/- brain phenotype reveals a small vestigial hippocampus...

  5. The adenovirus E1A binding protein BS69 is a corepressor of transcription through recruitment of N-CoR

    NARCIS (Netherlands)

    Masselink, H.; Bernards, R.A.

    2000-01-01

    BS69 was first identified as a protein that interacts directly with the transactivation domain (conserved region 3) of the 289R adenovirus type 5 E1A protein. We show here that BS69 is a potent repressor of transcription. BS69 mediates repression, at least in part, through interaction with the

  6. Overexpression of the novel MATE fluoroquinolone efflux pump FepA in Listeria monocytogenes is driven by inactivation of its local repressor FepR.

    Directory of Open Access Journals (Sweden)

    François Guérin

    Full Text Available Whereas fluoroquinolone resistance mainly results from target modifications in gram-positive bacteria, it is primarily due to active efflux in Listeria monocytogenes. The aim of this study was to dissect a novel molecular mechanism of fluoroquinolone resistance in this important human pathogen. Isogenic L. monocytogenes clinical isolates BM4715 and BM4716, respectively susceptible and resistant to fluoroquinolones, were studied. MICs of norfloxacin and ciprofloxacin were determined in the presence or in the absence of reserpine (10 mg/L. Strain BM4715 was susceptible to norfloxacin (MIC, 4 mg/L and ciprofloxacin (MIC, 0.5 mg/L whereas BM4716 was highly resistant to both drugs (MICs 128 and 32 mg/L, respectively. Reserpine was responsible for a 16-fold decrease in both norfloxacin and ciprofloxacin MICs against BM4716 suggesting efflux associated resistance. Whole-genome sequencing of the strains followed by comparative genomic analysis revealed a single point mutation in the gene for a transcriptional regulator, designated fepR (for fluoroquinolone efflux protein regulator belonging to the TetR family. The frame-shift mutation was responsible for the introduction of a premature stop codon resulting in an inactive truncated protein. Just downstream from fepR, the structural gene for an efflux pump of the MATE family (named FepA was identified. Gene expression was quantified by qRT-PCR and demonstrated that fepA expression was more than 64-fold higher in BM4716 than in BM4715. The clean deletion of the fepR gene from BM4715 was responsible for an overexpression of fepA with resistance to norfloxacin and ciprofloxacin, confirming the role of FepR as a local repressor of fepA. In conclusion, we demonstrated that overexpression of the new MATE efflux pump FepA is responsible for fluoroquinolone resistance in L. monocytogenes and secondary to inactivation of the FepR repressor.

  7. Segregation induced fingering instabilities in granular avalanches

    Science.gov (United States)

    Woodhouse, Mark; Thornton, Anthony; Johnson, Chris; Kokelaar, Pete; Gray, Nico

    2013-04-01

    It is important to be able to predict the distance to which a hazardous natural granular flows (e.g. snow slab avalanches, debris-flows and pyroclastic flows) might travel, as this information is vital for accurate assessment of the risks posed by such events. In the high solids fraction regions of these flows the large particles commonly segregate to the surface, where they are transported to the margins to form bouldery flow fronts. In many natural flows these bouldery margins experience a much greater frictional force, leading to frontal instabilities. These instabilities create levees that channelize the flow vastly increasing the run-out distance. A similar effect can be observed in dry granular experiments, which use a combination of small round and large rough particles. When this mixture is poured down an inclined plane, particle size segregation causes the large particles to accumulate near the margins. Being rougher, the large particles experience a greater friction force and this configuration (rougher material in front of smoother) can be unstable. The instability causes the uniform flow front to break up into a series of fingers. A recent model for particle size-segregation has been coupled to existing avalanche models through a particle concentration dependent friction law. In this talk numerical solutions of this coupled system are presented and compared to both large scale experiments carried out at the USGS flume and more controlled small scale laboratory experiments. The coupled depth-averaged model captures the accumulation of large particles at the flow front. We show this large particle accumulation at the head of the flow can lead to the break-up of the initially uniform front into a series of fingers. However, we are unable to obtain a fully grid-resolved numerical solution; the width of the fingers decreases as the grid is refined. By considering the linear stability of a steady, fully-developed, bidisperse granular layer it is shown that

  8. Finger-like voids induced by viscous fingering during phase inversion of alumina/PES/NMP suspensions

    KAUST Repository

    Wang, Bo

    2012-07-01

    The formation mechanism of phase-inversion ceramic hollow fibre membranes has not been well understood. In this paper, we report on the formation of finger-like macrovoids during non-solvent-induced phase inversion of alumina/PES/NMP suspensions. A membrane structure without such finger-like macrovoids was observed when the suspension was slowly immersed into pure ethanol or a mixture of 70. wt% NMP and 30. wt% water, whereas finger-like macrovoids occurred when the suspension was slid into the non-solvents at higher speeds. We found that the formation process of finger-like macrovoids could be fully or partially reversed when nascent membranes were taken out from water shortly after immersion, depending on the duration of the immersion. Splitting of the fingers during the formation of the macrovoids was also observed during the phase inversion of two alumina/PES/NMP suspensions. These experimental observations were not predicted by current theories of finger-like macrovoid formation in polymer membranes, but appear to mimic the well-known viscous fingering phenomenon. We therefore propose that in the phase inversion of ceramic suspensions, the viscous fingering phenomenon is an important mechanism in the formation of finger-like voids. © 2012 Elsevier B.V.

  9. Modelling salt finger formation using the Imperial College Ocean Model

    Science.gov (United States)

    MacTavish, F. P.; Cotter, C. J.; Piggott, M. D.

    2009-04-01

    We present numerical simulations of salt finger formation produced using the Imperial College Ocean Model (ICOM) which is a finite element model using adaptive meshing. Our aim is to validate the model against published data and to develop the capability to simulate salt finger formation using adaptive meshes. Salt fingering is a form of double-diffusion which occurs because heat diffuses more quickly than salt. When an area of warm, salty water overlies an area of colder, fresher water, an initial perturbation can lead to some of the water from the lower layer moving into the top layer. Its temperature then increases more quickly than its salinity, so that the water is less dense than its surroundings and it will rise up more. This process repeats to form salt fingers, with salt fingers also forming in the downward direction. Salt fingers play a role in oceanic mixing, in particular they are responsible for maintaining thermohaline staircases such as the C-SALT staircase which have been observed extensively, particularly in the tropics. The study of salt fingers could therefore improve our understanding of processes in the ocean, and inform the design of subgrid parameterisations in general circulation models. We used the salt finger formation test case of Oezgoekmen et al (1998) in order to validate ICOM. The formation of salt fingers is modelled by solving the Navier-Stokes equations for a two-dimensional rectangular area of Boussinesq fluid, beginning with two layers of water, the top warm and salty and the bottom cold and fresh, with parameters chosen to match the test case of Oezgoekmen et al (1998). The positions of the interfaces between the fingering layer and the mixed layers as well as the finger growth rate and the kinetic energy are plotted against time. The results are compared with those of Oezgoekmen et al (1998). We present results from structured meshes and preliminary results using adaptive meshing.

  10. The Oct1 homolog Nubbin is a repressor of NF-κB-dependent immune gene expression that increases the tolerance to gut microbiota.

    Science.gov (United States)

    Dantoft, Widad; Davis, Monica M; Lindvall, Jessica M; Tang, Xiongzhuo; Uvell, Hanna; Junell, Anna; Beskow, Anne; Engström, Ylva

    2013-09-06

    Innate immune responses are evolutionarily conserved processes that provide crucial protection against invading organisms. Gene activation by potent NF-κB transcription factors is essential both in mammals and Drosophila during infection and stress challenges. If not strictly controlled, this potent defense system can activate autoimmune and inflammatory stress reactions, with deleterious consequences for the organism. Negative regulation to prevent gene activation in healthy organisms, in the presence of the commensal gut flora, is however not well understood. We show that the Drosophila homolog of mammalian Oct1/POU2F1 transcription factor, called Nubbin (Nub), is a repressor of NF-κB/Relish-driven antimicrobial peptide gene expression in flies. In nub1 mutants, which lack Nub-PD protein, excessive expression of antimicrobial peptide genes occurs in the absence of infection, leading to a significant reduction of the numbers of cultivatable gut commensal bacteria. This aberrant immune gene expression was effectively blocked by expression of Nub from a transgene. We have identified an upstream regulatory region, containing a cluster of octamer sites, which is required for repression of antimicrobial peptide gene expression in healthy flies. Chromatin immunoprecipitation experiments demonstrated that Nub binds to octamer-containing promoter fragments of several immune genes. Gene expression profiling revealed that Drosophila Nub negatively regulates many genes that are involved in immune and stress responses, while it is a positive regulator of genes involved in differentiation and metabolism. This study demonstrates that a large number of genes that are activated by NF-κB/Relish in response to infection are normally repressed by the evolutionarily conserved Oct/POU transcription factor Nub. This prevents uncontrolled gene activation and supports the existence of a normal gut flora. We suggest that Nub protein plays an ancient role, shared with mammalian Oct

  11. The Glycerol-Dependent Metabolic Persistence of Pseudomonas putida KT2440 Reflects the Regulatory Logic of the GlpR Repressor

    Science.gov (United States)

    Nikel, Pablo I.; Romero-Campero, Francisco J.; Zeidman, Joshua A.; Goñi-Moreno, Ángel

    2015-01-01

    ABSTRACT The growth of the soil bacterium Pseudomonas putida KT2440 on glycerol as the sole carbon source is characterized by a prolonged lag phase, not observed with other carbon substrates. We examined the bacterial growth in glycerol cultures while monitoring the metabolic activity of individual cells. Fluorescence microscopy and flow cytometry, as well as the analysis of the temporal start of growth in single-cell cultures, revealed that adoption of a glycerol-metabolizing regime was not the result of a gradual change in the whole population but rather reflected a time-dependent bimodal switch between metabolically inactive (i.e., nongrowing) and fully active (i.e., growing) bacteria. A transcriptional Φ(glpD-gfp) fusion (a proxy of the glycerol-3-phosphate [G3P] dehydrogenase activity) linked the macroscopic phenotype to the expression of the glp genes. Either deleting glpR (encoding the G3P-responsive transcriptional repressor that controls the expression of the glpFKRD gene cluster) or altering G3P formation (by overexpressing glpK, encoding glycerol kinase) abolished the bimodal glpD expression. These manipulations eliminated the stochastic growth start by shortening the otherwise long lag phase. Provision of glpR in trans restored the phenotypes lost in the ΔglpR mutant. The prolonged nongrowth regime of P. putida on glycerol could thus be traced to the regulatory device controlling the transcription of the glp genes. Since the physiological agonist of GlpR is G3P, the arrangement of metabolic and regulatory components at this checkpoint merges a positive feedback loop with a nonlinear transcriptional response, a layout fostering the observed time-dependent shift between two alternative physiological states. PMID:25827416

  12. Induction of Pseudomonas syringae pv. tomato DC3000 MexAB-OprM multidrug efflux pump by flavonoids is mediated by the repressor PmeR.

    Science.gov (United States)

    Vargas, Paola; Felipe, Antonia; Michán, Carmen; Gallegos, María-Trinidad

    2011-10-01

    In this study, we have analyzed the expression of the Pseudomonas syringae pv. tomato DC3000 mexAB-oprM efflux pump operon and of the regulatory gene pmeR, and we have investigated the role of the PmeR protein on transcription from both promoters. We demonstrate that mexAB-oprM and pmeR are expressed in vivo at a relatively high and moderate basal level, respectively, which, in both cases, increases in the presence of different flavonoids and other compounds, such as butyl and methylparaben. We show that PmeR is the local repressor of the mexAB-oprM promoter and is able to regulate its own expression. The mechanism for this regulation includes binding to a pseudopalindromic operator site which overlaps both mexAB-oprM and pmeR promoters. We have also proven that flavonoids are able to interact with PmeR and induce a conformational change that interferes with the DNA binding ability of PmeR, thereby modulating mexAB-oprM and pmeR expression. Finally, we demonstrate by in vivo experiments that the PmeR/MexAB-OprM system contributes to the colonization of tomato plants. These results provide new insight into a transcriptional regulator and a transport system that play essential roles in the ability of P. syringae pv. tomato DC3000 to resist the action of flavonoids produced by the host.

  13. The Arabidopsis SUPERMAN protein is able to specifically bind DNA through its single Cys2–His2 zinc finger motif

    Science.gov (United States)

    Dathan, Nina; Zaccaro, Laura; Esposito, Sabrina; Isernia, Carla; Omichinski, James G.; Riccio, Andrea; Pedone, Carlo; Di Blasio, Benedetto; Fattorusso, Roberto; Pedone, Paolo V.

    2002-01-01

    The Arabidopsis SUPERMAN (SUP) gene has been shown to be important in maintaining the boundary between stamens and carpels, and is presumed to act by regulating cell proliferation. In this work, we show that the SUP protein, which contains a single Cys2–His2 zinc finger domain including the QALGGH sequence, highly conserved in the plant zinc finger proteins, binds DNA. Using a series of deletion mutants, it was determined that the minimal domain required for specific DNA binding (residues 15–78) includes the single zinc finger and two basic regions located on either side of this motif. Furthermore, amino acid substitutions in the zinc finger or in the basic regions, including a mutation that knocks out the function of the SUP protein in vivo (glycine 63 to aspartate), have been found to abolish the activity of the SUP DNA-binding domain. These results strongly suggest that the SUP protein functions in vivo by acting as a DNA-binding protein, likely involved in transcriptional regulation. The association of both an N-terminal and a C-terminal basic region with a single Cys2–His2 zinc finger represents a novel DNA-binding motif suggesting that the mechanism of DNA recognition adopted by the SUP protein is different from that described so far in other zinc finger proteins. PMID:12433998

  14. The LIM Homeodomain Transcription Factor LHX6

    Science.gov (United States)

    Zhang, Zichao; Gutierrez, Diana; Li, Xiao; Bidlack, Felicitas; Cao, Huojun; Wang, Jianbo; Andrade, Kelsey; Margolis, Henry C.; Amendt, Brad A.

    2013-01-01

    LHX6 is a LIM-homeobox transcription factor expressed during embryogenesis; however, the molecular mechanisms regulating LHX6 transcriptional activities are unknown. LHX6 and the PITX2 homeodomain transcription factor have overlapping expression patterns during tooth and craniofacial development, and in this report, we demonstrate new transcriptional mechanisms for these factors. PITX2 and LHX6 are co-expressed in the oral and dental epithelium and epithelial cell lines. Lhx6 expression is increased in Pitx2c transgenic mice and decreased in Pitx2 null mice. PITX2 activates endogenous Lhx6 expression and the Lhx6 promoter, whereas LHX6 represses its promoter activity. Chromatin immunoprecipitation experiments reveal endogenous PITX2 binding to the Lhx6 promoter. LHX6 directly interacts with PITX2 to inhibit PITX2 transcriptional activities and activation of multiple promoters. Bimolecular fluorescence complementation assays reveal an LHX6·PITX2 nuclear interaction in living cells. LHX6 has a dominant repressive effect on the PITX2 synergistic activation with LEF-1 and β-catenin co-factors. Thus, LHX6 acts as a transcriptional repressor and represses the expression of several genes involved in odontogenesis. We have identified specific defects in incisor, molar, mandible, bone, and root development and late stage enamel formation in Lhx6 null mice. Amelogenin and ameloblastin expression is reduced and/or delayed in the Lhx6 null mice, potentially resulting from defects in dentin deposition and ameloblast differentiation. Our results demonstrate that LHX6 regulates cell proliferation in the cervical loop and promotes cell differentiation in the anterior region of the incisor. We demonstrate new molecular mechanisms for LHX6 and an interaction with PITX2 for normal craniofacial and tooth development. PMID:23229549

  15. How salicylic acid takes transcriptional control over jasmonic acid signaling

    Directory of Open Access Journals (Sweden)

    Lotte eCaarls

    2015-03-01

    Full Text Available Transcriptional regulation is a central process in plant immunity. The induction or repression of defense genes is orchestrated by signaling networks that are directed by plant hormones of which salicylic acid (SA and jasmonic acid (JA are the major players. Extensive cross-communication between the hormone signaling pathways allows for fine tuning of transcriptional programs, determining resistance to invaders and trade-offs with plant development. Here, we give an overview of how SA can control transcriptional reprogramming of JA-induced genes in Arabidopsis thaliana. SA can influence activity and/or localization of transcriptional regulators by post-translational modifications of transcription factors and co-regulators. SA-induced redox changes, mediated by thioredoxins and glutaredoxins, modify transcriptional regulators that are involved in suppression of JA-dependent genes, such as NPR1 and TGA transcription factors, which affects their localization or DNA binding activity. Furthermore, SA can mediate sequestering of JA-responsive transcription factors away from their target genes by stalling them in the cytosol or in complexes with repressor proteins in the nucleus. SA also affects JA-induced transcription by inducing degradation of transcription factors with an activating role in JA signaling, as was shown for the ERF transcription factor ORA59. Additionally, SA can induce negative regulators, among which WRKY transcription factors, that can directly or indirectly inhibit JA-responsive gene expression. Finally, at the DNA level, modification of histones by SA-dependent factors can result in repression of JA-responsive genes. These diverse and complex regulatory mechanisms affect important signaling hubs in the integration of hormone signaling networks. Some pathogens have evolved effectors that highjack hormone crosstalk mechanisms for their own good, which are described in this review as well.

  16. substitute for Zn(II) in zinc fingers?

    Indian Academy of Sciences (India)

    Zinc finger domains consist of sequences of amino acids containing cysteine and histidine residues tetrahedrally coordinated to a zinc ion. The role of zinc in a DNA binding finger was considered purely structural due to the absence of redox chemistry in zinc. However, whether other metals e.g. Co(II) or Cd(II) can substitute ...

  17. Experience of Percutaneous Trigger Finger Release under Local ...

    African Journals Online (AJOL)

    Background: Trigger finger is a common disorder of upper extremity. Majority of the patients can be treated conservatively but some resistant cases eventually need surgery. Aim: The aim of this study is to evaluate the results of percutaneous trigger finger release under local anesthesia. Subjects and Methods: This is a ...

  18. Pattern of Trigger Finger among Patients Attending a Musculo ...

    African Journals Online (AJOL)

    Background: Trigger finger is a common finger problem thought to be due to thickening of tendon sheath with or without localized tendon thickening, resulting in a narrowed tunnel for tendon excursion with ultimate restriction of tendon movement. It can be seen in anyone, it is however seen frequently in diabetic patients and ...

  19. 21 CFR 888.3230 - Finger joint polymer constrained prosthesis.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Finger joint polymer constrained prosthesis. 888... constrained prosthesis. (a) Identification. A finger joint polymer constrained prosthesis is a device intended... generic type of device includes prostheses that consist of a single flexible across-the-joint component...

  20. Biomimetic finger extension mechanism for soft wearable hand rehabilitation devices.

    Science.gov (United States)

    Kim, Dong Hyun; Heo, Si-Hwan; Park, Hyung-Soon

    2017-07-01

    For the rehabilitation and assistance of the hand functions, wearable devices have been developed, and the interest in tendon driven mechanisms have especially increased since it allows light weight and compact design. The tendon driven hand rehabilitation devices provides grasping force via exo-tendons routed on the dorsal and palmar sides of the hand pulled by remotely located actuators. However, most of the devices were not able to provide natural joint extension sequence of the finger and showed hyperextension of finger joints because the tendons for extension were fixed at the fingertip, concentrating the torque at the distal interphalangeal joint. In this study, a ring-type biomimetic finger extension mechanism was developed, which mimics the origin, structure, and orientation of the extensor tendon. The biomimetic mechanism was evaluated by comparing the motion with voluntary finger extension and the motion made by other conventional tendon driven finger extension mechanisms. The biomimetic extension mechanism provided the same joint extension sequence with voluntary finger extension, and the fully extended posture was most close to the voluntary finger extension among the tendon-driven mechanisms used in the experiments. The joint angle differences between the proposed tendon mechanism and the voluntary finger extension was -1.2 °±3.4 °, -2.9°±2.0°, and -3.1°±8.0° for distal phalangeal, proximal phalangeal, and metacarpo-phalangeal joint, respectively.

  1. A biomechanical study of the finger pulley system during repair.

    Science.gov (United States)

    Amirouche, F; Gonzalez, M; Koldoff, J; Tioco, J; Ham, K

    2002-01-01

    This paper addresses the mechanics of the finger/pulley system when subjected to various excisions and repairs. Several cadaver hands were used to study the finger/pulley's function, finger joint dynamics, and the relationship between tendon excursion and finger joint angles of rotation. By using a method of continuous and simultaneous data acquisition of the entire finger joint's motion, a more detailed analysis was achieved. Our experimental investigation is based on the use of four micro-potentiometers inserted at the finger's joints and a pulley system to simulate tendon excursion. Using this procedure, a detailed kinematic analysis of the entire finger was performed. This included analysis of the intact hand, various pulley excisions, and reconstruction. In addition to introducing a new method of acquisition, a mathematical model was developed for the inverse dynamic analysis of the finger pulley system. From this model, the torques required at the joints for the motion were computed. The results provided new insight into possible ways of characterizing kinematic changes resulting from pulley damage and repair.

  2. Can We Call It "Stinky-finger Syndrome?"

    Science.gov (United States)

    Maqbool, Masood; War, Firdous Ahmed; Kumar, Mohit

    2017-01-01

    Many accounts refer to insertion of finger into anus mostly for gratification from stimulation of prostate gland, but index case Mr. M. continued doing this to get rid of constipation that eventually led to feelings of guilt, stinky fingers, not able to defecate normally, and dysphoric emotions. Further research is needed to find out the phenomenology of this condition.

  3. In-depth study of DNA binding of Cys2His2 finger domains in testis zinc-finger protein.

    Directory of Open Access Journals (Sweden)

    Chun-Chi Chou

    Full Text Available Previously, we identified that both fingers 1 and 2 in the three Cys2His2 zinc-finger domains (TZD of testis zinc-finger protein specifically bind to its cognate DNA; however, finger 3 is non-sequence-specific. To gain insights into the interaction mechanism, here we further investigated the DNA-binding characteristics of TZD bound to non-specific DNAs and its finger segments bound to cognate DNA. TZD in non-specific DNA binding showed smaller chemical shift perturbations, as expected. However, the direction of shift perturbation, change of DNA imino-proton NMR signal, and dynamics on the 15N backbone atom significantly differed between specific and non-specific binding. Using these unique characteristics, we confirmed that the three single-finger segments (TZD1, TZD2 and TZD3 and the two-finger segment (TZD23 non-specifically bind to the cognate DNA. In comparison, the other two-finger segment (TZD12 binding to the cognate DNA features simultaneous non-specific and semi-specific binding, both slowly exchanged in terms of NMR timescale. The process of TZD binding to the cognate DNA is likely stepwise: initially TZD non-specifically binds to DNA, then fingers 1 and 2 insert cooperatively into the major groove of DNA by semi-specific binding, and finally finger 3 non-specifically binds to DNA, which promotes the specific binding on fingers 1 and 2 and stabilizes the formation of a specific TZD-DNA complex.

  4. 78 FR 68907 - Agency Information Collection (Hand and Finger Conditions Disability Benefits Questionnaire...

    Science.gov (United States)

    2013-11-15

    ... Finger Conditions Disability Benefits Questionnaire) Under OMB Review AGENCY: Veterans Benefits... Control No. 2900- NEW (Hand and Finger Conditions Disability Benefits Questionnaire)'' in any... Benefits Questionnaire)''. SUPPLEMENTARY INFORMATION: Title: Hand and Finger Conditions Disability Benefits...

  5. H-NS mediated repression of CRISPR-based immunity in Escherichia coli K12 can be relieved by the transcription activator LeuO

    OpenAIRE

    Westra, Edze Rients; Pul, Ümit; Heidrich, Nadja; Jore, Matthijs Miklas; Lundgren, Magnus; Stratmann, Thomas; Wurm, Reinhild; Raine, Amanda; Mescher, Melina; Heereveld, Luc Van; Mastop, Marieke; Wagner, E. Gerhart H.; Schnetz, Karin; Van Der Oost, John; Wagner, Rolf

    2010-01-01

    Abstract The recently discovered prokaryotic CRISPR/Cas defense system provides immunity against viral infections and plasmid conjugation. It has been demonstrated that in Escherichia coli transcription of the Cascade genes (casABCDE) and to some extent the CRISPR array, is repressed by heat-stable nucleoid-structuring (H-NS) protein, a global transcriptional repressor. Here we elaborate on the control of the E. coli CRISPR/Cas system, and study the effect on CRISPR-based anti-vira...

  6. Developmentally regulated expression of a human ''finger'' - containing gene encoded by the 5' half of the ret transforming gene

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, M.; Inaguma, Y.; Hiai, H.; Hirose, F.

    1988-04-01

    The authors isolated and sequenced a cDNA clone of the human gene encoded by the 5' half of the ret transforming gene. The nucleotide sequence indicates that it encodes a protein with ''finger'' structures which represent putative metal- and nucleic acid-binding domains. Transcriptions of this gene was detected at high levels in a variety of human and rodent tumor cell lines, mouse testis, and embryos. In addition, a unique transcript was observed in testis RNA. When the expression of the unique transcript was examined at different stages of spermatogenesis, a striking increase in mRNA levels accompanied progression from meiotic prophase pachytene spermatocytes to postmeiotic round spermatids. This finger-containing gene may thus function in male germ cell development.

  7. Messenger RNA Interferase RelE Controls relBE Transcription by Conditional Cooperativity

    DEFF Research Database (Denmark)

    Overgaard, Martin; Borch, Jonas; Jørgensen, Mikkel G

    2008-01-01

    by binding to one or more operators in the promoter region while the toxin functions as a co-repressor of transcription. Interestingly, the toxin can also stimulate TA operon transcription. Here we analyse mechanistic aspects of how RelE of Escherichia coli can function both as a co-repressor and derepressor...... of relBE transcription. When RelB was in excess to RelE, two trimeric RelB(2)*RelE complexes bound cooperatively to two adjacent operator-sites in the relBE promoter region and repressed transcription. By contrast, RelE in excess stimulated relBE transcription and released the RelB(2)*RelE complex from...... operator DNA. A mutational analysis of the operator-sites showed that RelE in excess counteracted cooperative binding of the RelB(2)*RelE complexes to the operator-sites. Thus, RelE controls relBE transcription by conditional cooperativity....

  8. Structure of the MecI repressor from Staphylococcus aureus in complex with the cognate DNA operator of mec

    Energy Technology Data Exchange (ETDEWEB)

    Safo, Martin K., E-mail: msafo@vcu.edu [Department of Medicinal Chemistry, School of Pharmacy and Institute for Structural Biology and Drug Discovery, Virginia Commonwealth University, Richmond, Virginia 23298 (United States); Ko, Tzu-Ping [Institute of Biological Chemistry, Academia Sinica, Taipei 11529,Taiwan (China); Musayev, Faik N. [Department of Medicinal Chemistry, School of Pharmacy and Institute for Structural Biology and Drug Discovery, Virginia Commonwealth University, Richmond, Virginia 23298 (United States); Zhao, Qixun [Department of Medicine and Department of Microbiology/Immunology, Virginia Commonwealth University, Richmond, Virginia 23298 (United States); Wang, Andrew H.-J. [Institute of Biological Chemistry, Academia Sinica, Taipei 11529,Taiwan (China); Archer, Gordon L. [Department of Medicine and Department of Microbiology/Immunology, Virginia Commonwealth University, Richmond, Virginia 23298 (United States); Department of Medicinal Chemistry, School of Pharmacy and Institute for Structural Biology and Drug Discovery, Virginia Commonwealth University, Richmond, Virginia 23298 (United States)

    2006-04-01

    The up-and-down binding of dimeric MecI to mecA dyad DNA may account for the cooperative effect of the repressor. The dimeric repressor MecI regulates the mecA gene that encodes the penicillin-binding protein PBP-2a in methicillin-resistant Staphylococcus aureus (MRSA). MecI is similar to BlaI, the repressor for the blaZ gene of β-lactamase. MecI and BlaI can bind to both operator DNA sequences. The crystal structure of MecI in complex with the 32 base-pair cognate DNA of mec was determined to 3.8 Å resolution. MecI is a homodimer and each monomer consists of a compact N-terminal winged-helix domain, which binds to DNA, and a loosely packed C-terminal helical domain, which intertwines with its counter-monomer. The crystal contains horizontal layers of virtual DNA double helices extending in three directions, which are separated by perpendicular DNA segments. Each DNA segment is bound to two MecI dimers. Similar to the BlaI–mec complex, but unlike the MecI–bla complex, the MecI repressors bind to both sides of the mec DNA dyad that contains four conserved sequences of TACA/TGTA. The results confirm the up-and-down binding to the mec operator, which may account for cooperative effect of the repressor.

  9. Tangential finger forces use mechanical advantage during static grasping.

    Science.gov (United States)

    Slota, Gregory P; Latash, Mark L; Zatsiorsky, Vladimir M

    2012-02-01

    When grasping and manipulating objects, the central controller utilizes the mechanical advantage of the normal forces of the fingers for torque production. Whether the same is valid for tangential forces is unknown. The main purpose of this study was to determine the patterns of finger tangential forces and the use of mechanical advantage as a control mechanism when dealing with objects of nonuniform finger positioning. A complementary goal was to explore the interaction of mechanical advantage (moment arm) and the role a finger has as a torque agonist/antagonist with respect to external torques (±0.4 N m). Five 6-df force/torque transducers measured finger forces while subjects held a prism handle (6 cm width × 9 cm height) with and without a single finger displaced 2 cm (handle width). The effect of increasing the tangential moment arm was significant (p forces (in >70% of trials) and hence creating greater moments. Thus, the data provides evidence that the grasping system as a rule utilizes mechanical advantage for generating tangential forces. The increase in tangential force was independent of whether the finger was acting as a torque agonist or antagonist, revealing their effects to be additive.

  10. Torque control of underactuated tendon-driven fingers

    Directory of Open Access Journals (Sweden)

    M. E. Abdallah

    2011-02-01

    Full Text Available Given an underactuated tendon-driven finger, the finger posture is underdetermined and can move freely ("flop" in a region of slack tendons. This work shows that such an underactuated finger can be operated in tendon force control (rather than position control with effective performance. The force control eliminates the indeterminate slack while commanding a parameterized space of desired torques. The torque will either push the finger to the joint limits or wrap around an external object with variable torque – behavior that is sufficient for primarily gripping fingers. In addition, introducing asymmetric joint radii to the design allows the finger to command an expanded range of joint torques and to scan an expanded set of external surfaces. This study is motivated by the design and control of the secondary fingers of the NASA-GM R2 humanoid hand.

    This paper was presented at the IFToMM/ASME International Workshop on Underactuated Grasping (UG2010, 19 August 2010, Montréal, Canada.

  11. GATA family transcriptional factors: emerging suspects in hematologic disorders.

    Science.gov (United States)

    Gao, Juehua; Chen, Yi-Hua; Peterson, LoAnn C

    2015-01-01

    GATA transcription factors are zinc finger DNA binding proteins that regulate transcription during development and cell differentiation. The three important GATA transcription factors GATA1, GATA2 and GATA3 play essential roles in the development and maintenance of hematopoietic systems. GATA1 is required for the erythroid and megakaryocytic commitment during hematopoiesis. GATA2 is crucial for the proliferation and survival of early hematopoietic cells, and is also involved in lineage specific transcriptional regulation as the dynamic partner of GATA1. GATA3 plays an essential role in T lymphoid cell development and immune regulation. As a result, mutations in genes encoding the GATA transcription factors or alteration in the protein expression level or their function have been linked to a variety of human hematologic disorders. In this review, we summarized the current knowledge regarding the disrupted biologic function of GATA in various hematologic disorders.

  12. Safety mechanism assisted by the repressor of tetracycline (SMART) vaccinia virus vectors for vaccines and therapeutics.

    Science.gov (United States)

    Grigg, Patricia; Titong, Allison; Jones, Leslie A; Yilma, Tilahun D; Verardi, Paulo H

    2013-09-17

    Replication-competent viruses, such as Vaccinia virus (VACV), are powerful tools for the development of oncolytic viral therapies and elicit superior immune responses when used as vaccine and immunotherapeutic vectors. However, severe complications from uncontrolled viral replication can occur, particularly in immunocompromised individuals or in those with other predisposing conditions. VACVs constitutively expressing interferon-γ (IFN-γ) replicate in cell culture indistinguishably from control viruses; however, they replicate in vivo to low or undetectable levels, and are rapidly cleared even in immunodeficient animals. In an effort to develop safe and highly effective replication-competent VACV vectors, we established a system to inducibly express IFN-γ. Our SMART (safety mechanism assisted by the repressor of tetracycline) vectors are designed to express the tetracycline repressor under a constitutive VACV promoter and IFN-γ under engineered tetracycline-inducible promoters. Immunodeficient SCID mice inoculated with VACVs not expressing IFN-γ demonstrated severe weight loss, whereas those given VACVs expressing IFN-γ under constitutive VACV promoters showed no signs of infection. Most importantly, mice inoculated with a VACV expressing the IFN-γ gene under an inducible promoter remained healthy in the presence of doxycycline, but exhibited severe weight loss in the absence of doxycycline. In this study, we developed a safety mechanism for VACV based on the conditional expression of IFN-γ under a tightly controlled tetracycline-inducible VACV promoter for use in vaccines and oncolytic cancer therapies.

  13. DAX1 suppresses FXR transactivity as a novel co-repressor

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jin; Lu, Yan; Liu, Ruya; Xiong, Xuelian; Zhang, Zhijian; Zhang, Xianfeng [Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Department of Endocrinology and Metabolism, Rui-Jin Hospital, Shanghai Jiao-Tong University School of Medicine, Shanghai 200025 (China); Ning, Guang, E-mail: guangning@gmail.com.cn [Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Department of Endocrinology and Metabolism, Rui-Jin Hospital, Shanghai Jiao-Tong University School of Medicine, Shanghai 200025 (China); The Key Laboratory of Endocrine Tumors and The Division of Endocrine and Metabolic Diseases, E-Institute of Shanghai Universities, Shanghai 200025 (China); Li, Xiaoying, E-mail: lixy@sibs.ac.cn [Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Department of Endocrinology and Metabolism, Rui-Jin Hospital, Shanghai Jiao-Tong University School of Medicine, Shanghai 200025 (China); The Key Laboratory of Endocrine Tumors and The Division of Endocrine and Metabolic Diseases, E-Institute of Shanghai Universities, Shanghai 200025 (China)

    2011-09-09

    Highlights: {yields} DAX1 is co-localized with FXR and interacts with FXR. {yields} DAX1 acts as a negative regulator of FXR. {yields} Three LXXLL motifs in the N-terminus of DAX1 were required. {yields} DAX1 suppresses FXR transactivation by competing with co-activators. -- Abstract: Bile acid receptor FXR (farnesoid X receptor) is a key regulator of hepatic bile acid, glucose and lipid homeostasis through regulation of numerous genes involved in the process of bile acid, triglyceride and glucose metabolism. DAX1 (dosage-sensitive sex reversal adrenal hypoplasia congenital critical region on X chromosome, gene 1) is an atypical member of the nuclear receptor family due to lack of classical DNA-binding domains and acts primarily as a co-repressor of many nuclear receptors. Here, we demonstrated that DAX1 is co-localized with FXR in the nucleus and acted as a negative regulator of FXR through a physical interaction with FXR. Our study showed that over-expression of DAX1 down-regulated the expression of FXR target genes, whereas knockdown of DAX1 led to their up-regulation. Furthermore, three LXXLL motifs in the N-terminus of DAX1 were required for the full repression of FXR transactivation. In addition, our study characterized that DAX1 suppresses FXR transactivation via competing with co-activators such as SRC-1 and PGC-1{alpha}. In conclusion, DAX1 acts as a co-repressor to negatively modulate FXR transactivity.

  14. DAX1 suppresses FXR transactivity as a novel co-repressor

    International Nuclear Information System (INIS)

    Li, Jin; Lu, Yan; Liu, Ruya; Xiong, Xuelian; Zhang, Zhijian; Zhang, Xianfeng; Ning, Guang; Li, Xiaoying

    2011-01-01

    Highlights: → DAX1 is co-localized with FXR and interacts with FXR. → DAX1 acts as a negative regulator of FXR. → Three LXXLL motifs in the N-terminus of DAX1 were required. → DAX1 suppresses FXR transactivation by competing with co-activators. -- Abstract: Bile acid receptor FXR (farnesoid X receptor) is a key regulator of hepatic bile acid, glucose and lipid homeostasis through regulation of numerous genes involved in the process of bile acid, triglyceride and glucose metabolism. DAX1 (dosage-sensitive sex reversal adrenal hypoplasia congenital critical region on X chromosome, gene 1) is an atypical member of the nuclear receptor family due to lack of classical DNA-binding domains and acts primarily as a co-repressor of many nuclear receptors. Here, we demonstrated that DAX1 is co-localized with FXR in the nucleus and acted as a negative regulator of FXR through a physical interaction with FXR. Our study showed that over-expression of DAX1 down-regulated the expression of FXR target genes, whereas knockdown of DAX1 led to their up-regulation. Furthermore, three LXXLL motifs in the N-terminus of DAX1 were required for the full repression of FXR transactivation. In addition, our study characterized that DAX1 suppresses FXR transactivation via competing with co-activators such as SRC-1 and PGC-1α. In conclusion, DAX1 acts as a co-repressor to negatively modulate FXR transactivity.

  15. The relation between the anthropometric characteristics of fingers and cancer

    Directory of Open Access Journals (Sweden)

    Omid Mardanshahi

    2017-07-01

    Full Text Available Anthropometry is a science of human body measurement that could be used for manufacturing artificial limbs or prosthesis, investigating body differences between populations, utilizing in forensics and criminology, or even in the diagnosis of some diseases. Two of the most important anthropometric characteristics are dermatoglyphic patterns and finger length. Many studies have evaluated the relation between these two characteristics in different diseases such as cancers. It assumed that dermatoglyphic patterns and finger length could be used as predictors of some cancers such as gastric, ovarian, prostate, testicular, and breast cancers. In this review, we evaluated the relation between dermatoglyphic variability and finger length in different cancers more precisely.

  16. ZFNGenome: A comprehensive resource for locating zinc finger nuclease target sites in model organisms

    Directory of Open Access Journals (Sweden)

    Voytas Daniel F

    2011-01-01

    Full Text Available Abstract Background Zinc Finger Nucleases (ZFNs have tremendous potential as tools to facilitate genomic modifications, such as precise gene knockouts or gene replacements by homologous recombination. ZFNs can be used to advance both basic research and clinical applications, including gene therapy. Recently, the ability to engineer ZFNs that target any desired genomic DNA sequence with high fidelity has improved significantly with the introduction of rapid, robust, and publicly available techniques for ZFN design such as the Oligomerized Pool ENgineering (OPEN method. The motivation for this study is to make resources for genome modifications using OPEN-generated ZFNs more accessible to researchers by creating a user-friendly interface that identifies and provides quality scores for all potential ZFN target sites in the complete genomes of several model organisms. Description ZFNGenome is a GBrowse-based tool for identifying and visualizing potential target sites for OPEN-generated ZFNs. ZFNGenome currently includes a total of more than 11.6 million potential ZFN target sites, mapped within the fully sequenced genomes of seven model organisms; S. cerevisiae, C. reinhardtii, A. thaliana, D. melanogaster, D. rerio, C. elegans, and H. sapiens and can be visualized within the flexible GBrowse environment. Additional model organisms will be included in future updates. ZFNGenome provides information about each potential ZFN target site, including its chromosomal location and position relative to transcription initiation site(s. Users can query ZFNGenome using several different criteria (e.g., gene ID, transcript ID, target site sequence. Tracks in ZFNGenome also provide "uniqueness" and ZiFOpT (Zinc Finger OPEN Targeter "confidence" scores that estimate the likelihood that a chosen ZFN target site will function in vivo. ZFNGenome is dynamically linked to ZiFDB, allowing users access to all available information about zinc finger reagents, such as the

  17. nalD Encodes a Second Repressor of the mexAB-oprM Multidrug Efflux Operon of Pseudomonas aeruginosa▿

    OpenAIRE

    Morita, Yuji; Cao, Lily; Gould, Virginia C.; Avison, Matthew B.; Poole, Keith

    2006-01-01

    The Pseudomonas aeruginosa nalD gene encodes a TetR family repressor with homology to the SmeT and TtgR repressors of the smeDEF and ttgABC multidrug efflux systems of Stenotrophomonas maltophilia and Pseudomonas putida, respectively. A sequence upstream of mexAB-oprM and overlapping a second promoter for this efflux system was very similar to the SmeT and TtgR operator sequences, and NalD binding to this region was, in fact, demonstrated. Moreover, increased expression from this promoter was...

  18. Control of viscous fingering by nanoparticles

    Science.gov (United States)

    Sabet, Nasser; Hassanzadeh, Hassan; Abedi, Jalal

    2017-12-01

    A substantial viscosity increase by the addition of a low dose of nanoparticles to the base fluids can well influence the dynamics of viscous fingering. There is a lack of detailed theoretical studies that address the effect of the presence of nanoparticles on unstable miscible displacements. In this study, the impact of nonreactive nanoparticle presence on the stability and subsequent mixing of an originally unstable binary system is examined using linear stability analysis (LSA) and pseudospectral-based direct numerical simulations (DNS). We have parametrized the role of both nondepositing and depositing nanoparticles on the stability of miscible displacements using the developed static and dynamic parametric analyses. Our results show that nanoparticles have the potential to weaken the instabilities of an originally unstable system. Our LSA and DNS results also reveal that nondepositing nanoparticles can be used to fully stabilize an originally unstable front while depositing particles may act as temporary stabilizers whose influence diminishes in the course of time. In addition, we explain the existing inconsistencies concerning the effect of the nanoparticle diffusion coefficient on the dynamics of the system. This study provides a basis for further research on the application of nanoparticles for control of viscosity-driven instabilities.

  19. Dermal pocketing following distal finger replantation.

    Science.gov (United States)

    Puhaindran, Mark E; Paavilainen, Pasi; Tan, David M K; Peng, Yeong Pin; Lim, Aymeric Y T

    2010-08-01

    Replantation is an ideal technique for reconstruction following fingertip amputation as it provides 'like for like' total reconstruction of the nail complex, bone pulp tissue and skin with no donor-site morbidity. However, fingertips are often not replanted because veins cannot be found or are thought to be too small to repair. Attempts at 'cap-plasty' or pocketing of replanted tips with and without microvascular anastomosis have been done in the past with varying degrees of success. We prospectively followed up a group of patients who underwent digital replantation and dermal pocketing in the palm to evaluate the outcome of this procedure. There were 10 patients with 14 amputated digits (two thumbs, five index, four middle, two ring and one little) who underwent dermal pocketing of the amputated digit following replantation. Among the 14 digits that were treated with dermal pocketing, 11 survived completely, one had partial atrophy and two were completely lost. Complications encountered included finger stiffness (two patients) and infection of the replanted fingertip with osteomyelitis of the distal phalanx (one patient). We believe that this technique can help increase the chance of survival for distal replantation with an acceptable salvage rate of 85% in our series. Copyright 2009 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  20. Crystal structure of enterococcus faecalis sly A-like transcriptional factor.

    Energy Technology Data Exchange (ETDEWEB)

    Wu, R.; Zhang, R.; Zagnitko, O.; Dementieva, I.; Maltsev, N.; Watson, J. D.; Laskowski, R.; Gornicki, P.; Joachimiak, A.; Univ. of Chicago; European Bioinformatics Inst.

    2003-05-30

    The crystal structure of a SlyA transcriptional regulator at 1.6 {angstrom} resolution is presented, and structural relationships between members of the MarR/SlyA family are discussed. The SlyA family, which includes SlyA, Rap, Hor, and RovA proteins, is widely distributed in bacterial and archaeal genomes. Current evidence suggests that SlyA-like factors act as repressors, activators, and modulators of gene transcription. These proteins have been shown to up-regulate the expression of molecular chaperones, acid-resistance proteins, and cytolysin, and down-regulate several biosynthetic enzymes. The structure of SlyA from Enterococcus faecalis, determined as a part of an ongoing structural genomics initiative (www.mcsg.anl.gov), revealed the same winged helix DNA-binding motif that was recently found in the MarR repressor from Escherichia coli and the MexR repressor from Pseudomonas aeruginosa, a sequence homologue of MarR. Phylogenetic analysis of the MarR/SlyA family suggests that Sly is placed between the SlyA and MarR subfamilies and shows significant sequence similarity to members of both subfamilies.

  1. Development of Functional Recovery Training Device for Hemiplegic Fingers with Finger-expansion Facilitation Exercise by Stretch Reflex

    Science.gov (United States)

    Yu, Yong; Iwashita, Hisashi; Kawahira, Kazumi; Hayashi, Ryota

    This paper develops a functional recovery training device to perform repetition facilitating exercise for hemiplegic finger rehabilitation. On the facilitation exercise, automatic finger expansion can be realized and facilitated by stretch reflex, where a stimulation forces is applied instantaneously on flexion finger for making strech reflex and resistance forces are applied for maintaining the strech reflex. In this paper, novel parallel mechanisms, force sensing system with high sensitivity and resistance accompanying cooperation control method are proposed for sensing, controlling and realizing the stimulation force, resistance forces, strech reflex and repetition facilitating exercise. The effectivities and performances of the device are shown by some experiments.

  2. RNA-guided Transcriptional Regulation in Plants via dCas9 Chimeric Proteins

    KAUST Repository

    Baazim, Hatoon

    2014-05-01

    Developing targeted genome regulation approaches holds much promise for accelerating trait discovery and development in agricultural biotechnology. Clustered Regularly Interspaced Palindromic Repeats (CRISPRs)/CRISPR associated (Cas) system provides bacteria and archaea with an adaptive molecular immunity mechanism against invading nucleic acids through phages and conjugative plasmids. The type II CRISPR/Cas system has been adapted for genome editing purposes across a variety of cell types and organisms. Recently, the catalytically inactive Cas9 (dCas9) protein combined with guide RNAs (gRNAs) were used as a DNA-targeting platform to modulate the expression patterns in bacterial, yeast and human cells. Here, we employed this DNA-targeting system for targeted transcriptional regulation in planta by developing chimeric dCas9-based activators and repressors. For example, we fused to the C-terminus of dCas9 with the activation domains of EDLL and TAL effectors, respectively, to generate transcriptional activators, and the SRDX repression domain to generate transcriptional repressor. Our data demonstrate that the dCas9:EDLL and dCas9:TAD activators, guided by gRNAs complementary to promoter elements, induce strong transcriptional activation on episomal targets in plant cells. Moreover, our data suggest that the dCas9:SRDX repressor and the dCas9:EDLL and dCas9:TAD activators are capable of markedly repressing or activating, respectively, the transcription of an endogenous genomic target. Our data indicate that the CRISPR/dCas9:TFs DNA targeting system can be used in plants as a functional genomic tool and for biotechnological applications.

  3. Genome-wide identification of PHD-finger genes and expression pattern analysis under various treatments in moso bamboo (Phyllostachys edulis).

    Science.gov (United States)

    Gao, Yameng; Liu, Huanlong; Wang, Yujiao; Li, Fei; Xiang, Yan

    2018-02-01

    Plant homeodomain (PHD)-finger proteins are a class of important zinc-finger transcription factors responsible for regulating transcription and the chromatin state and responsive to various stresses. The family genes have been reported in many plants, but there is little information about PHD-finger genes in moso bamboo. In this study, 60 PHD-finger genes (PePHD1-60) were identified in moso bamboo and classified into 11 subfamilies (A-K) based on phylogenetic analysis. Gene structure and conserved motif analysis showed that these genes contained different numbers of introns but had similar motif organizations within each subfamily. Multiple sequence alignment revealed that the PHD-finger proteins possessed conserved structural domain sequences. In addition, the family underwent purifying selection during evolution and experienced a large-scale duplication event around 7.69-15.4 million years ago. Most importantly, the expression profiles of young leaves (YL), mature leaves (L), roots (R), stems (S), shoots (Sh) and rhizomes (Rh) displayed that they might involve in the formation of these tissues. Based on promoter analysis of 16 putative stress-related genes, quantitative real-time PCR assays were performed using moso bamboo leaves and showed that these genes were differentially regulated under abscisic acid (ABA), drought, low temperature and NaCl treatments. Therefore, the results reveal that PePHD genes play crucial roles in organ formation and response to multiple environmental stress conditions of moso bamboo, which will make for further function analysis of PHD-finger genes in plants. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  4. Novel strategies to overcome expression problems encountered with toxic proteins: application to the production of Lac repressor proteins for NMR studies

    NARCIS (Netherlands)

    Romanuka, J.; van den Bulke, H.; Kaptein, R.; Boelens, R.; Folkers, G.E.

    2009-01-01

    NMR studies of structural aspects of allosteric regulation by the Lac repressor requires overexpression and isotope labeling of the protein. The size of the repressor makes it a challenging target, putting constraints on both expression conditions and sample preparation methods to overcome problems

  5. Fuzzy based finger vein recognition with rotation invariant feature matching

    Science.gov (United States)

    Ezhilmaran, D.; Joseph, Rose Bindu

    2017-11-01

    Finger vein recognition is a promising biometric with commercial applications which is explored widely in the recent years. In this paper, a finger vein recognition system is proposed using rotation invariant feature descriptors for matching after enhancing the finger vein images with an interval type-2 fuzzy method. SIFT features are extracted and matched using a matching score based on Euclidian distance. Rotation invariance of the proposed method is verified in the experiment and the results are compared with SURF matching and minutiae matching. It is seen that rotation invariance is verified and the poor quality issues are solved efficiently with the designed system of finger vein recognition during the analysis. The experiments underlines the robustness and reliability of the interval type-2 fuzzy enhancement and SIFT feature matching.

  6. Tension Distribution in a Tendon-Driven Robotic Finger

    Science.gov (United States)

    Abdallah, Muhammad E. (Inventor); Platt, Robert (Inventor); Wampler, II, Charles W. (Inventor)

    2013-01-01

    A method is provided for distributing tension among tendons of a tendon-driven finger in a robotic system, wherein the finger characterized by n degrees of freedom and n+1 tendons. The method includes determining a maximum functional tension and a minimum functional tension of each tendon of the finger, and then using a controller to distribute tension among the tendons, such that each tendon is assigned a tension value less than the maximum functional tension and greater than or equal to the minimum functional tension. The method satisfies the minimum functional tension while minimizing the internal tension in the robotic system, and satisfies the maximum functional tension without introducing a coupled disturbance to the joint torques. A robotic system includes a robot having at least one tendon-driven finger characterized by n degrees of freedom and n+1 tendons, and a controller having an algorithm for controlling the tendons as set forth above.

  7. The effects of vibration-reducing gloves on finger vibration

    Science.gov (United States)

    Welcome, Daniel E.; Dong, Ren G.; Xu, Xueyan S.; Warren, Christopher; McDowell, Thomas W.

    2015-01-01

    Vibration-reducing (VR) gloves have been used to reduce the hand-transmitted vibration exposures from machines and powered hand tools but their effectiveness remains unclear, especially for finger protection. The objectives of this study are to determine whether VR gloves can attenuate the vibration transmitted to the fingers and to enhance the understanding of the mechanisms of how these gloves work. Seven adult male subjects participated in the experiment. The fixed factors evaluated include hand force (four levels), glove condition (gel-filled, air bladder, no gloves), and location of the finger vibration measurement. A 3-D laser vibrometer was used to measure the vibrations on the fingers with and without wearing a glove on a 3-D hand-arm vibration test system. This study finds that the effect of VR gloves on the finger vibration depends on not only the gloves but also their influence on the distribution of the finger contact stiffness and the grip effort. As a result, the gloves increase the vibration in the fingertip area but marginally reduce the vibration in the proximal area at some frequencies below 100 Hz. On average, the gloves reduce the vibration of the entire fingers by less than 3% at frequencies below 80 Hz but increase at frequencies from 80 to 400 Hz. At higher frequencies, the gel-filled glove is more effective at reducing the finger vibration than the air bladder-filled glove. The implications of these findings are discussed. Relevance to industry Prolonged, intensive exposure to hand-transmitted vibration can cause hand-arm vibration syndrome. Vibration-reducing gloves have been used as an alternative approach to reduce the vibration exposure. However, their effectiveness for reducing finger-transmitted vibrations remains unclear. This study enhanced the understanding of the glove effects on finger vibration and provided useful information on the effectiveness of typical VR gloves at reducing the vibration transmitted to the fingers. The new

  8. Transcriptional Control of Brown Fat Determination by PRDM16

    OpenAIRE

    Seale, Patrick; Kajimura, Shingo; Yang, Wenli; Chin, Sherry; Rohas, Lindsay; Uldry, Marc; Tavernier, Geneviève; Langin, Dominique; Spiegelman, Bruce M.

    2007-01-01

    Brown fat cells are specialized to dissipate energy and can counteract obesity; however, the transcriptional basis of their determination is largely unknown. We show here that the zinc-finger protein PRDM16 is highly enriched in brown fat cells compared to white fat cells. When expressed in white fat cell progenitors, PRDM16 activates a robust brown fat phenotype including induction of PGC-1α, UCP1 and type 2 deiodinase expression, and a remarkable increase in uncoupled respiration. Transgeni...

  9. Robotic Hand with Flexible Fingers for Grasping Cylindrical Objects

    OpenAIRE

    柴田, 瑞穂

    2015-01-01

    In this manuscript, a robotic hand for grasping a cylindrical object is proposed. This robotic hand has flexible fingers that can hold a cylindrical object during moving. We introduce a grasping strategy for a cylindrical object in terms of state transition graph. In this strategy the robotic hand picks up the cylindrical object utilizing a suction device before the hand grasp the object. We also design the flexible fingers; then, we investigate the validity of this robotic hand via several e...

  10. Finger avulsion injuries: A report of four cases

    Directory of Open Access Journals (Sweden)

    Fejjal N

    2008-01-01

    Full Text Available Injury that occurs to a finger wearing a ring though rare can have grave consequences. It is a preventable injury which has a peculiar mode of trauma that is usually occupational. Injury ranges from simple contusion to degloving of soft tissues to traumatic amputation. We hereby report our experience of four cases of finger avulsion injuries due to a ring and discuss their variable clinical presentation and individualized management.

  11. Finger blood content, light transmission, and pulse oximetry errors.

    Science.gov (United States)

    Craft, T M; Lawson, R A; Young, J D

    1992-01-01

    The changes in light emitting diode current necessary to maintain a constant level of light incident upon a photodetector were measured in 20 volunteers at the two wavelengths employed by pulse oximeters. Three states of finger blood content were assessed; exsanguinated, hyperaemic, and normal. The changes in light emitting diode current with changes in finger blood content were small and are not thought to represent a significant source of error in saturation as measured by pulse oximetry.

  12. Downward finger displacement distinguishes Parkinson disease dementia from Alzheimer disease.

    Science.gov (United States)

    Lieberman, Abraham; Deep, Aman; Shi, Jiong; Dhall, Rohit; Shafer, Saulena; Moguel-Cobos, Guillermo; Dhillon, Ravneet; Frames, Christopher W; McCauley, Margaret

    2018-02-01

    Purpose/Aim of the study: To study finger displacement in patients with Parkinson disease dementia (PDD) and in patients with Alzheimer disease (AD). We examined 56 patients with PDD and 35 with AD. Patients were examined during their regular outpatient clinic visit. Finger displacement was measured by observers not actively involved in the study using a creative grid ruler for all PDD and AD patients. Finger displacement was examined by asking patients to point their index fingers toward the grid ruler with the nails facing upward. Patients were asked to maintain the pointing position for 15 s. After 15 s, patients were asked to close their eyes for another 15 s while maintaining the same position. A positive result was downward index finger displacement of ≥5 cm within the 15-second time window with eyes closed. Of the 56 PDD patients, 53 had bilateral finger displacement of >5 cm. In comparison, of the 35 AD patients, only 1 patient had minimal displacement. Results of the non-invasive finger displacement test may provide insight, on an outpatient basis, of the integrity of subcortical-cortical circuits. Downward finger displacement, especially bilateral downward displacement, may signal the extensive disruption of subcortical-cortical circuits that occurs in PDD patients. AChE: acetylcholinesterase; AD: Alzheimer disease; DLB: dementia with Lewy bodies; ET: essential tremor; MDS-UPDRS: Movement Disorder Society-sponsored Unified Parkinson's Disease Rating Scale; MMSE: Mini-Mental State Examination; PD: Parkinson disease; PDD: Parkinson disease dementia.

  13. Reciprocal occupancy of BCL6 and STAT5 on Growth Hormone target genes: contrasting transcriptional outcomes and promoter-specific roles of p300 and HDAC3.

    Science.gov (United States)

    Lin, Grace; LaPensee, Christopher R; Qin, Zhaohui S; Schwartz, Jessica

    2014-09-01

    Expression of the Growth Hormone (GH)-stimulated gene Socs2 (Suppressor of Cytokine Signaling 2) is mediated by the transcription activator STAT5 (Signal Transducer and Activator of Transcription 5) and the transcription repressor BCL6 (B-Cell Lymphoma 6). ChIP-Sequencing identified Cish (Cytokine-Inducible SH2-containing protein) and Bcl6 as having similar patterns of reciprocal occupancy by BCL6 and STAT5 in response to GH, though GH stimulates Cish and inhibits Bcl6 expression. The co-activator p300 occupied Socs2, Cish and Bcl6 promoters, and enhanced STAT5-mediated activation of Socs2 and Cish. In contrast, on Bcl6, p300 functioned as a repressor and inhibited in conjunction with STAT5 or BCL6. The co-repressor HDAC3 (Histone deacetylase 3) inhibited the Socs2, Cish and Bcl6 promoters in the presence of STAT5. Thus transcriptional outcomes on GH-regulated genes occupied by BCL6 and STAT5 are determined in a promoter-specific fashion by co-regulatory proteins which mediate the distinction between activating and repressive transcription factors. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  14. Elastic fingering in rotating Hele-Shaw flows

    KAUST Repository

    Carvalho, Gabriel D.

    2014-05-21

    The centrifugally driven viscous fingering problem arises when two immiscible fluids of different densities flow in a rotating Hele-Shaw cell. In this conventional setting an interplay between capillary and centrifugal forces makes the fluid-fluid interface unstable, leading to the formation of fingered structures that compete dynamically and reach different lengths. In this context, it is known that finger competition is very sensitive to changes in the viscosity contrast between the fluids. We study a variant of such a rotating flow problem where the fluids react and produce a gellike phase at their separating boundary. This interface is assumed to be elastic, presenting a curvature-dependent bending rigidity. A perturbative weakly nonlinear approach is used to investigate how the elastic nature of the interface affects finger competition events. Our results unveil a very different dynamic scenario, in which finger length variability is not regulated by the viscosity contrast, but rather determined by two controlling quantities: a characteristic radius and a rigidity fraction parameter. By properly tuning these quantities one can describe a whole range of finger competition behaviors even if the viscosity contrast is kept unchanged. © 2014 American Physical Society.

  15. Integrating optical finger motion tracking with surface touch events

    Science.gov (United States)

    MacRitchie, Jennifer; McPherson, Andrew P.

    2015-01-01

    This paper presents a method of integrating two contrasting sensor systems for studying human interaction with a mechanical system, using piano performance as the case study. Piano technique requires both precise small-scale motion of fingers on the key surfaces and planned large-scale movement of the hands and arms. Where studies of performance often focus on one of these scales in isolation, this paper investigates the relationship between them. Two sensor systems were installed on an acoustic grand piano: a monocular high-speed camera tracking the position of painted markers on the hands, and capacitive touch sensors attach to the key surfaces which measure the location of finger-key contacts. This paper highlights a method of fusing the data from these systems, including temporal and spatial alignment, segmentation into notes and automatic fingering annotation. Three case studies demonstrate the utility of the multi-sensor data: analysis of finger flexion or extension based on touch and camera marker location, timing analysis of finger-key contact preceding and following key presses, and characterization of individual finger movements in the transitions between successive key presses. Piano performance is the focus of this paper, but the sensor method could equally apply to other fine motor control scenarios, with applications to human-computer interaction. PMID:26082732

  16. High-frequency ultrasonographic examination of the finger pulley system.

    Science.gov (United States)

    Boutry, Nathalie; Titécat, Marie; Demondion, Xavier; Glaude, Eddy; Fontaine, Christian; Cotten, Anne

    2005-10-01

    The purpose of this study was to determine the ability of high-frequency ultrasonography to provide for direct evaluation of the annular and cruciform finger pulley system. In the first part of the work, a cadaveric study was performed to outline the normal anatomy of the annular and cruciform finger pulley system. Eighteen cadaveric hands were cut (n = 10) or dissected (n = 8). Two musculoskeletal radiologists retrospectively reviewed in consensus the photographs of anatomic sections and dissections. This cadaveric study gave the 2 readers the opportunity to learn the normal anatomy of the finger pulley system. In the second part of the work, the annular and cruciform finger pulley system of 20 hands of volunteers was evaluated by ultrasonography with a 17-MHz linear transducer. Images were retrospectively analyzed by means of consensus of the 2 radiologists with respect to the visibility of each finger pulley. For annular (A) pulleys, high frequency ultrasonography showed A1, A2, A3, and A4 in 100%, 100%, 65%, and 100% of cases, respectively. For cruciform (C) pulleys, high-frequency ultrasonography showed only C1 in 45% of cases. Direct visualization of A5, C2, and C3 was not possible. High-frequency ultrasonography allows excellent depiction of finger pulleys except for annular pulley A5 and cruciform pulleys C2 and C3.

  17. Fluidic Channels Produced by Electro Hydrodynamic Viscous Fingering

    Science.gov (United States)

    Behler, Kristopher; Wetzel, Eric

    2010-03-01

    Viscous fingering is a term describing fingerlike extensions of liquid from a column of low viscosity liquid that has been injected into a more viscous liquid. The modification of viscous fingering, known as electro hydrodynamic viscous fingering (EHVF), utilizes large electrical potentials of 10-60 kV. The fingers see a reduction in size and increase in branching behavior due to the potential applied to the system. The resulting finely structured patterns are analogous to biological systems such as blood vessels and the lymphatic system. In this study silicone oils and water were studied in thin channel Hele-Shaw cells. The interfacial tension was optimized by altering the surfactant concentration in the silicone oils. EHVF of liquid filled packed beds consisting of beads and silicone oils showed retardation of the relaxation of the fingers after the voltage was turned off. Decreased relaxation provides a means to solidify patterns into a curable material, such as polydimethylsiloxane (PDMS). After the water is evacuated from the fingers, the cured materials then possess hollow channels that can be refilled and emptied, thus creating an artificial circulatory system.

  18. Integrating optical finger motion tracking with surface touch events

    Directory of Open Access Journals (Sweden)

    Jennifer eMacRitchie

    2015-06-01

    Full Text Available This paper presents a method of integrating two contrasting sensor systems for studying human interaction with a mechanical system, using piano performance as the case study. Piano technique requires both precise small-scale motion of fingers on the key surfaces and planned large-scale movement of the hands and arms. Where studies of performance often focus on one of these scales in isolation, this paper investigates the relationship between them. Two sensor systems were installed on an acoustic grand piano: a monocular high-speed camera tracking the position of painted markers on the hands, and capacitive touch sensors attach to the key surfaces which measure the location of finger-key contacts. This paper highlights a method of fusing the data from these systems, including temporal and spatial alignment, segmentation into notes and automatic fingering annotation. Three case studies demonstrate the utility of the multi-sensor data: analysis of finger flexion or extension based on touch and camera marker location, timing analysis of finger-key contact preceding and following key presses, and characterisation of individual finger movements in the transitions between successive key presses. Piano performance is the focus of this paper, but the sensor method could equally apply to other fine motor control scenarios, with applications to human-computer interaction.

  19. Pressure head distribution during unstable flow in relation to the formation and dissipation of fingers

    NARCIS (Netherlands)

    Hiroyuki Cho,; Rooij, de G.H.

    2002-01-01

    Wetting front instability creates a shallow induction zone from which fingers emerge that rapidly transport water and solutes downwards. How the induction zone affects finger location and spacing is unknown. In the moist subsoil, fingers may well dissipate because the finger tips no longer have to

  20. Digital finger: beyond phenomenological figures of touch

    Directory of Open Access Journals (Sweden)

    Mika Elo

    2012-02-01

    Full Text Available Mika Elo is a postdoctoral researcher and lecturer in visual culture at Aalto University School of Arts, Design and Architecture (Aalto-ARTS, Helsinki. His research interests include theory of photographic media, philosophical media theory, and artistic research. He is participating in discussions in these areas in the capacity of curator, visual artist and researcher. He has published articles in Finnish, German, and English among others on Benjamin, Nancy, artistic research and photography theory. His doctoral thesis Valokuvan medium [The Medium of Photography] was published in Finnish in 2005 (Tutkijaliitto, Helsinki. In 2009–2011 he worked in the Figures of Touch research project (figuresoftouch.com, and since 2011 he is the director of Media Aesthetics research group at Aalto-ARTS, Department of Media.Author Biography The article reflects on digitality and interface design in terms of the multiple senses of touch. Touching is presented as a “pathic” sense of being exposed, which implies that touching exceeds the tactile and even the phenomenal world. A particular focus is set on Aristotle's and Husserl's ways of thematizing the sense of touch. In this way, two extremes of the phenomenological thinking of touching are articulated: touching as an indistinct and heterogeneous constituent of sensitivity and touching as the guarantor of immediacy of the sense experience. Referring to Derrida's critical notes concerning haptocentrism, the article attempts to problematize the hand and the finger as phenomenological figures of touch and as holds of haptic realism. The article concludes that insofar as digital interface design aims at haptic realism it conceives of the sense of touch in terms of narcissistic feedback and thus tends to conceal the pathic moment of touching.

  1. Comparative analysis of chromatin binding by Sex Comb on Midleg (SCM) and other polycomb group repressors at a Drosophila Hox gene.

    Science.gov (United States)

    Wang, Liangjun; Jahren, Neal; Miller, Ellen L; Ketel, Carrie S; Mallin, Daniel R; Simon, Jeffrey A

    2010-06-01

    Sex Comb on Midleg (SCM) is a transcriptional repressor in the Polycomb group (PcG), but its molecular role in PcG silencing is not known. Although SCM can interact with Polycomb repressive complex 1 (PRC1) in vitro, biochemical studies have indicated that SCM is not a core constituent of PRC1 or PRC2. Nevertheless, SCM is just as critical for Drosophila Hox gene silencing as canonical subunits of these well-characterized PcG complexes. To address functional relationships between SCM and other PcG components, we have performed chromatin immunoprecipitation studies using cultured Drosophila Schneider line 2 (S2) cells and larval imaginal discs. We find that SCM associates with a Polycomb response element (PRE) upstream of the Ubx gene which also binds PRC1, PRC2, and the DNA-binding PcG protein Pleiohomeotic (PHO). However, SCM is retained at this Ubx PRE despite genetic disruption or knockdown of PHO, PRC1, or PRC2, suggesting that SCM chromatin targeting does not require prior association of these other PcG components. Chromatin immunoprecipitations (IPs) to test the consequences of SCM genetic disruption or knockdown revealed that PHO association is unaffected, but reduced levels of PRE-bound PRC2 and PRC1 were observed. We discuss these results in light of current models for recruitment of PcG complexes to chromatin targets.

  2. Comparative Analysis of Chromatin Binding by Sex Comb on Midleg (SCM) and Other Polycomb Group Repressors at a Drosophila Hox Gene▿

    Science.gov (United States)

    Wang, Liangjun; Jahren, Neal; Miller, Ellen L.; Ketel, Carrie S.; Mallin, Daniel R.; Simon, Jeffrey A.

    2010-01-01

    Sex Comb on Midleg (SCM) is a transcriptional repressor in the Polycomb group (PcG), but its molecular role in PcG silencing is not known. Although SCM can interact with Polycomb repressive complex 1 (PRC1) in vitro, biochemical studies have indicated that SCM is not a core constituent of PRC1 or PRC2. Nevertheless, SCM is just as critical for Drosophila Hox gene silencing as canonical subunits of these well-characterized PcG complexes. To address functional relationships between SCM and other PcG components, we have performed chromatin immunoprecipitation studies using cultured Drosophila Schneider line 2 (S2) cells and larval imaginal discs. We find that SCM associates with a Polycomb response element (PRE) upstream of the Ubx gene which also binds PRC1, PRC2, and the DNA-binding PcG protein Pleiohomeotic (PHO). However, SCM is retained at this Ubx PRE despite genetic disruption or knockdown of PHO, PRC1, or PRC2, suggesting that SCM chromatin targeting does not require prior association of these other PcG components. Chromatin immunoprecipitations (IPs) to test the consequences of SCM genetic disruption or knockdown revealed that PHO association is unaffected, but reduced levels of PRE-bound PRC2 and PRC1 were observed. We discuss these results in light of current models for recruitment of PcG complexes to chromatin targets. PMID:20351181

  3. Mechanism of Iron-Dependent Repressor (IdeR Activation and DNA Binding: A Molecular Dynamics and Protein Structure Network Study.

    Directory of Open Access Journals (Sweden)

    Soma Ghosh

    2015-12-01

    Full Text Available Metalloproteins form a major class of enzymes in the living system that are involved in crucial biological functions such as catalysis, redox reactions and as 'switches' in signal transductions. Iron dependent repressor (IdeR is a metal-sensing transcription factor that regulates free iron concentration in Mycobacterium tuberculosis. IdeR is also known to promote bacterial virulence, making it an important target in the field of therapeutics. Mechanistic details of how iron ions modulate IdeR such that it dimerizes and binds to DNA is not understood clearly. In this study, we have performed molecular dynamic simulations and integrated it with protein structure networks to study the influence of iron on IdeR structure and function. A significant structural variation between the metallated and the non-metallated system is observed. Our simulations clearly indicate the importance of iron in stabilizing its monomeric subunit, which in turn promotes dimerization. However, the most striking results are obtained from the simulations of IdeR-DNA complex in the absence of metals, where at the end of 100ns simulations, the protein subunits are seen to rapidly dissociate away from the DNA, thereby forming an excellent resource to investigate the mechanism of DNA binding. We have also investigated the role of iron as an allosteric regulator of IdeR that positively induces IdeR-DNA complex formation. Based on this study, a mechanistic model of IdeR activation and DNA binding has been proposed.

  4. Identification of PNG kinase substrates uncovers interactions with the translational repressor TRAL in the oocyte-to-embryo transition.

    Science.gov (United States)

    Hara, Masatoshi; Lourido, Sebastian; Petrova, Boryana; Lou, Hua Jane; Von Stetina, Jessica R; Kashevsky, Helena; Turk, Benjamin E; Orr-Weaver, Terry L

    2018-02-26

    The Drosophila Pan Gu (PNG) kinase complex regulates hundreds of maternal mRNAs that become translationally repressed or activated as the oocyte transitions to an embryo. In a previous paper (Hara et al., 2017), we demonstrated PNG activity is under tight developmental control and restricted to this transition. Here, examination of PNG specificity showed it to be a Thr-kinase yet lacking a clear phosphorylation site consensus sequence. An unbiased biochemical screen for PNG substrates identified the conserved translational repressor Trailer Hitch (TRAL). Phosphomimetic mutation of the PNG phospho-sites in TRAL reduced its ability to inhibit translation in vitro. In vivo, mutation of tral dominantly suppressed png mutants and restored Cyclin B protein levels. The repressor Pumilio (PUM) has the same relationship with PNG, and we also show that PUM is a PNG substrate. Furthermore, PNG can phosphorylate BICC and ME31B, repressors that bind TRAL in cytoplasmic RNPs. Therefore, PNG likely promotes translation at the oocyte-to-embryo transition by phosphorylating and inactivating translational repressors. © 2018, Hara et al.

  5. Structure of the effector-binding domain of the arabinose repressor AraR from Bacillus subtilis

    Czech Academy of Sciences Publication Activity Database

    Procházková, Kateřina; Čermáková, Kateřina; Pachl, Petr; Sieglová, Irena; Fábry, Milan; Otwinowski, Z.; Řezáčová, Pavlína

    2012-01-01

    Roč. 68, č. 2 (2012), s. 176-185 ISSN 0907-4449 R&D Projects: GA MŠk ME08016 Institutional research plan: CEZ:AV0Z40550506; CEZ:AV0Z50520514 Keywords : repressor * dimerization * effector binding * isothermal titration calorimetry Subject RIV: CE - Biochemistry Impact factor: 14.103, year: 2012

  6. Structure of the Mecl Repressor from Staphylococcus aureus in Complex with the Cognate DNA Operator of mec

    Energy Technology Data Exchange (ETDEWEB)

    Safo,M.; Ko, T.; Musayev, F.; Zhao, Q.; Wang, A.; Archer, G.

    2006-01-01

    The dimeric repressor MecI regulates the mecA gene that encodes the penicillin-binding protein PBP-2a in methicillin-resistant Staphylococcus aureus (MRSA). MecI is similar to BlaI, the repressor for the blaZ gene of {beta}-lactamase. MecI and BlaI can bind to both operator DNA sequences. The crystal structure of MecI in complex with the 32 base-pair cognate DNA of mec was determined to 3.8 Angstroms resolution. MecI is a homodimer and each monomer consists of a compact N-terminal winged-helix domain, which binds to DNA, and a loosely packed C-terminal helical domain, which intertwines with its counter-monomer. The crystal contains horizontal layers of virtual DNA double helices extending in three directions, which are separated by perpendicular DNA segments. Each DNA segment is bound to two MecI dimers. Similar to the BlaI-mec complex, but unlike the MecI-bla complex, the MecI repressors bind to both sides of the mec DNA dyad that contains four conserved sequences of TACA/TGTA. The results confirm the up-and-down binding to the mec operator, which may account for cooperative effect of the repressor.

  7. Structural and dynamics studies of a truncated variant of CI repressor from bacteriophage TP901-1

    DEFF Research Database (Denmark)

    Rasmussen, Kim Krighaar; Frandsen, Kristian E. H.; Erba, Elisabetta Boeri

    2016-01-01

    The CI repressor from the temperate bacteriophage TP901-1 consists of two folded domains, an N-terminal helix-turn-helix DNA-binding domain (NTD) and a C-terminal oligomerization domain (CTD), which we here suggest to be further divided into CTD1 and CTD2. Full-length CI is a hexameric protein...

  8. Sequence, expression and tissue localization of a gene encoding a makorin RING zinc-finger protein in germinating rice (Oryza sativa L. ssp. Japonica) seeds.

    Science.gov (United States)

    Arumugam, Thangavelu U; Davies, Eric; Morita, Eugene Hayato; Abe, Shunnosuke

    2007-01-01

    The makorin (MKRN) RING finger protein gene family encodes proteins (makorins) with a characteristic array of zinc-finger motifs and which are present in a wide array of eukaryotes. In the present study, we analyzed the structure and expression of a putative makorin RING finger protein gene in rice (Oryza sativa L. ssp. Japonica cv. Nipponbare). From the analysis of the genomic (AP003543), mRNA (AK120250) and deduced protein (BAD61603) sequences of the putative MKRN gene of rice, obtained from GenBank, we found that it was indeed a bona fide member of the MKRN gene family. The rice MKRN cDNA encoded a protein with four C3H zinc-finger-motifs, one putative Cys-His zinc-finger motif, and one RING zinc-finger motif. The presence of this distinct motif organization and overall amino acid identity clearly indicate that this gene is indeed a true MKRN ortholog. We isolated RNA from embryonic axes of rice seeds at various stages of imbibition and germination and studied the temporal expression profile of MKRN by RT-PCR. This analysis revealed that MKRN transcripts were present at all the time points studied. It was at very low levels in dry seeds, increased slowly during imbibition and germination, and slightly declined in the seedling growth stage. After 6days of germination, an organ-dependent expression pattern of MKRN was observed: highest in roots and moderate in leaves. Similarly to MKRN transcripts, transcripts of cytoskeletal actin and tubulin were also detected in dry embryos, steadily increased during imbibition and germination and leveled off after 24h of germination. We studied the spatial expression profile of MKRN in rice tissues, by using a relatively fast, simple and effective non-radioactive mRNA in situ hybridization (NRISH) technique, which provided the first spatial experimental data that hints at the function of a plant makorin. This analysis revealed that MKRN transcripts were expressed in young plumules, lateral root primordia, leaf primordia

  9. Tyrosine binding and promiscuity in the arginine repressor from the pathogenic bacterium Corynebacterium pseudotuberculosis.

    Science.gov (United States)

    Mariutti, Ricardo Barros; Ullah, Anwar; Araujo, Gabriela Campos; Murakami, Mario Tyago; Arni, Raghuvir Krishnaswamy

    2016-07-08

    The arginine repressor (ArgR) regulates arginine biosynthesis in a number of microorganisms and consists of two domains interlinked by a short peptide; the N-terminal domain is involved in DNA binding and the C-terminal domain binds arginine and forms a hexamer made-up of a dimer of trimers. The crystal structure of the C-terminal domain of ArgR from the pathogenic Corynebacterium pseudotuberculosis determined at 1.9 Å resolution contains a tightly bound tyrosine at the arginine-binding site indicating hitherto unobserved promiscuity. Structural analysis of the binding pocket displays clear molecular adaptations to accommodate tyrosine binding suggesting the possible existence of an alternative regulatory process in this pathogenic bacterium. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Female Infertility Caused by Mutations in the Oocyte-Specific Translational Repressor PATL2

    KAUST Repository

    Maddirevula, Sateesh

    2017-09-29

    Infertility is a relatively common disorder of the reproductive system and remains unexplained in many cases. In vitro fertilization techniques have uncovered previously unrecognized infertility phenotypes, including oocyte maturation arrest, the molecular etiology of which remains largely unknown. We report two families affected by female-limited infertility caused by oocyte maturation failure. Positional mapping and whole-exome sequencing revealed two homozygous, likely deleterious variants in PATL2, each of which fully segregates with the phenotype within the respective family. PATL2 encodes a highly conserved oocyte-specific mRNP repressor of translation. Previous data have shown the strict requirement for PATL2 in oocyte-maturation in model organisms. Data gathered from the families in this study suggest that the role of PATL2 is conserved in humans and expand our knowledge of the factors that are necessary for female meiosis.

  11. Effect of the linkers between the zinc fingers in zinc finger protein 809 on gene silencing and nuclear localization

    Energy Technology Data Exchange (ETDEWEB)

    Ichida, Yu, E-mail: ichida-y@ncchd.go.jp; Utsunomiya, Yuko; Onodera, Masafumi

    2016-03-18

    Zinc finger protein 809 (ZFP809) belongs to the Kruppel-associated box-containing zinc finger protein (KRAB-ZFP) family and functions in repressing the expression of Moloney murine leukemia virus (MoMLV). ZFP809 binds to the primer-binding site (PBS)located downstream of the MoMLV-long terminal repeat (LTR) and induces epigenetic modifications at integration sites, such as repressive histone modifications and de novo DNA methylation. KRAB-ZFPs contain consensus TGEKP linkers between C2H2 zinc fingers. The phosphorylation of threonine residues within linkers leads to the inactivation of zinc finger binding to target sequences. ZFP809 also contains consensus linkers between zinc fingers. However, the function of ZFP809 linkers remains unknown. In the present study, we constructed ZFP809 proteins containing mutated linkers and examined their ability to silence transgene expression driven by MLV, binding ability to MLV PBS, and cellular localization. The results of the present study revealed that the linkers affected the ability of ZFP809 to silence transgene expression. Furthermore, this effect could be partly attributed to changes in the localization of ZFP809 proteins containing mutated linkers. Further characterization of ZFP809 linkers is required for understanding the functions and features of KRAB-ZFP-containing linkers. - Highlights: • ZFP809 has three consensus linkers between the zinc fingers. • Linkers are required for ZFP809 to silence transgene expression driven by MLV-LTR. • Linkers affect the precise nuclear localization of ZFP809.

  12. Effects of cytosine methylation on transcription factor binding sites

    KAUST Repository

    Medvedeva, Yulia A

    2014-03-26

    Background: DNA methylation in promoters is closely linked to downstream gene repression. However, whether DNA methylation is a cause or a consequence of gene repression remains an open question. If it is a cause, then DNA methylation may affect the affinity of transcription factors (TFs) for their binding sites (TFBSs). If it is a consequence, then gene repression caused by chromatin modification may be stabilized by DNA methylation. Until now, these two possibilities have been supported only by non-systematic evidence and they have not been tested on a wide range of TFs. An average promoter methylation is usually used in studies, whereas recent results suggested that methylation of individual cytosines can also be important.Results: We found that the methylation profiles of 16.6% of cytosines and the expression profiles of neighboring transcriptional start sites (TSSs) were significantly negatively correlated. We called the CpGs corresponding to such cytosines " traffic lights" We observed a strong selection against CpG " traffic lights" within TFBSs. The negative selection was stronger for transcriptional repressors as compared with transcriptional activators or multifunctional TFs as well as for core TFBS positions as compared with flanking TFBS positions.Conclusions: Our results indicate that direct and selective methylation of certain TFBS that prevents TF binding is restricted to special cases and cannot be considered as a general regulatory mechanism of transcription. 2013 Medvedeva et al.; licensee BioMed Central Ltd.

  13. CTCF: Comprehending The Complex Functions of an 11 zinc finger transcription factor

    NARCIS (Netherlands)

    H.E. Heath (Helen Elizabeth)

    2007-01-01

    textabstractIn a multi-cellular organism, every somatic cell nucleus broadly contains the same sequence of DNA, yet clearly most cells are very different to each other. Specific sets of genes encoding proteins become activated whereas others are repressed. Within the genome, independently regulated

  14. Zinc Finger Transcription Factors as Novel Genetic Switches to Modulate Metastatic Progression of Breast Tumors

    Science.gov (United States)

    2008-05-01

    predicted specificity of the individual ZF lexicons. Aminoacids shown in red, blue and pink represent the ZF α-helical positions –1, +3 and +6, which...additive effect, and antagonism , respectively. Statistical Analysis Real-time PCR and viability experiments were repeated thrice using three...2007;1:84–90. 44. Chou TC. Theoretical basis, experimental design, and computerized simulation of synergism and antagonism in drug combination studies

  15. Novel structural features in two ZHX homeodomains derived from a systematic study of single and multiple domains

    NARCIS (Netherlands)

    Bird, L.E.; Ren, J.; Nettleship, J.E.; Folkers, G.E.|info:eu-repo/dai/nl/162277202; Owens, RJ; Stammers, D.K.

    2010-01-01

    Zhx1 to 3 (zinc-fingers and homeoboxes) form a set of paralogous genes encoding multi-domain proteins. ZHX proteins consist of two zinc fingers followed by five homeodomains. ZHXs have biological roles in cell cycle control by acting as co-repressors of the transcriptional regulator Nuclear Factor

  16. Loss of the Caenorhabditis elegans pocket protein LIN-35 reveals MuvB's innate function as the repressor of DREAM target genes.

    Science.gov (United States)

    Goetsch, Paul D; Garrigues, Jacob M; Strome, Susan

    2017-11-01

    The DREAM (Dp/Retinoblastoma(Rb)-like/E2F/MuvB) transcriptional repressor complex acts as a gatekeeper of the mammalian cell cycle by establishing and maintaining cellular quiescence. How DREAM's three functional components, the E2F-DP heterodimer, the Rb-like pocket protein, and the MuvB subcomplex, form and function at target gene promoters remains unknown. The current model invokes that the pocket protein links E2F-DP and MuvB and is essential for gene repression. We tested this model by assessing how the conserved yet less redundant DREAM system in Caenorhabditis elegans is affected by absence of the sole C. elegans pocket protein LIN-35. Using a LIN-35 protein null mutant, we analyzed the assembly of E2F-DP and MuvB at promoters that are bound by DREAM and the level of expression of those "DREAM target genes" in embryos. We report that LIN-35 indeed mediates the association of E2F-DP and MuvB, a function that stabilizes DREAM subunit occupancy at target genes. In the absence of LIN-35, the occupancy of E2F-DP and MuvB at most DREAM target genes decreases dramatically and many of those genes become upregulated. The retention of E2F-DP and MuvB at some target gene promoters in lin-35 null embryos allowed us to test their contribution to DREAM target gene repression. Depletion of MuvB, but not E2F-DP, in the sensitized lin-35 null background caused further upregulation of DREAM target genes. We conclude that the pocket protein functions primarily to support MuvB-mediated repression of DREAM targets and that transcriptional repression is the innate function of the evolutionarily conserved MuvB complex. Our findings provide important insights into how mammalian DREAM assembly and disassembly may regulate gene expression and the cell cycle.

  17. Evolution of Metal(Loid) Binding Sites in Transcriptional Regulators

    Energy Technology Data Exchange (ETDEWEB)

    Ordonez, E.; Thiyagarajan, S.; Cook, J.D.; Stemmler, T.L.; Gil, J.A.; Mateos, L.M.; Rosen, B.P.

    2009-05-22

    Expression of the genes for resistance to heavy metals and metalloids is transcriptionally regulated by the toxic ions themselves. Members of the ArsR/SmtB family of small metalloregulatory proteins respond to transition metals, heavy metals, and metalloids, including As(III), Sb(III), Cd(II), Pb(II), Zn(II), Co(II), and Ni(II). These homodimeric repressors bind to DNA in the absence of inducing metal(loid) ion and dissociate from the DNA when inducer is bound. The regulatory sites are often three- or four-coordinate metal binding sites composed of cysteine thiolates. Surprisingly, in two different As(III)-responsive regulators, the metalloid binding sites were in different locations in the repressor, and the Cd(II) binding sites were in two different locations in two Cd(II)-responsive regulators. We hypothesize that ArsR/SmtB repressors have a common backbone structure, that of a winged helix DNA-binding protein, but have considerable plasticity in the location of inducer binding sites. Here we show that an As(III)-responsive member of the family, CgArsR1 from Corynebacterium glutamicum, binds As(III) to a cysteine triad composed of Cys{sup 15}, Cys{sup 16}, and Cys{sup 55}. This binding site is clearly unrelated to the binding sites of other characterized ArsR/SmtB family members. This is consistent with our hypothesis that metal(loid) binding sites in DNA binding proteins evolve convergently in response to persistent environmental pressures.

  18. Zinc finger protein 148 is dispensable for primitive and definitive hematopoiesis in mice.

    Directory of Open Access Journals (Sweden)

    Anna Nilton

    Full Text Available Hematopoiesis is regulated by transcription factors that induce cell fate and differentiation in hematopoietic stem cells into fully differentiated hematopoietic cell types. The transcription factor zinc finger protein 148 (Zfp148 interacts with the hematopoietic transcription factor Gata1 and has been implicated to play an important role in primitive and definitive hematopoiesis in zebra fish and mouse chimeras. We have recently created a gene-trap knockout mouse model deficient for Zfp148, opening up for analyses of hematopoiesis in a conventional loss-of-function model in vivo. Here, we show that Zfp148-deficient neonatal and adult mice have normal or slightly increased levels of hemoglobin, hematocrit, platelets and white blood cells, compared to wild type controls. Hematopoietic lineages in bone marrow, thymus and spleen from Zfp148 (gt/gt mice were further investigated by flow cytometry. There were no differences in T-cells (CD4 and CD8 single positive cells, CD4 and CD8 double negative/positive cells in either organ. However, the fraction of CD69- and B220-positive cells among lymphocytes in spleen was slightly lower at postnatal day 14 in Zfp148 (gt/gt mice compared to wild type mice. Our results demonstrate that Zfp148-deficient mice generate normal mature hematopoietic populations thus challenging earlier studies indicating that Zfp148 plays a critical role during hematopoietic development.

  19. Making fingers and words count in a cognitive robot.

    Science.gov (United States)

    De La Cruz, Vivian M; Di Nuovo, Alessandro; Di Nuovo, Santo; Cangelosi, Angelo

    2014-01-01

    Evidence from developmental as well as neuroscientific studies suggest that finger counting activity plays an important role in the acquisition of numerical skills in children. It has been claimed that this skill helps in building motor-based representations of number that continue to influence number processing well into adulthood, facilitating the emergence of number concepts from sensorimotor experience through a bottom-up process. The act of counting also involves the acquisition and use of a verbal number system of which number words are the basic building blocks. Using a Cognitive Developmental Robotics paradigm we present results of a modeling experiment on whether finger counting and the association of number words (or tags) to fingers, could serve to bootstrap the representation of number in a cognitive robot, enabling it to perform basic numerical operations such as addition. The cognitive architecture of the robot is based on artificial neural networks, which enable the robot to learn both sensorimotor skills (finger counting) and linguistic skills (using number words). The results obtained in our experiments show that learning the number words in sequence along with finger configurations helps the fast building of the initial representation of number in the robot. Number knowledge, is instead, not as efficiently developed when number words are learned out of sequence without finger counting. Furthermore, the internal representations of the finger configurations themselves, developed by the robot as a result of the experiments, sustain the execution of basic arithmetic operations, something consistent with evidence coming from developmental research with children. The model and experiments demonstrate the importance of sensorimotor skill learning in robots for the acquisition of abstract knowledge such as numbers.

  20. Identification of domains mediating transcription activation, repression, and inhibition in the paired-related homeobox protein, Prx2 (S8).

    Science.gov (United States)

    Norris, R A; Kern, M J

    2001-02-01

    Despite the growing information concerning the developmental importance of the Prx2 protein, the structural determinants of Prx2 function are poorly understood. To gain insight into the transcription regulatory regions of the Prx2 protein, we generated a series of truncation mutants. Both the Prx2 response element (PRE) and a portion of the tenascin promoter, a downstream target of Prx2, were used as reporters in transient transfection assays. This analysis showed that a conserved domain (PRX), found in both Prx1 and Prx2, activated transcription in NIH 3T3 cells. This PRX domain, as well as other functional regions of Prx2, demonstrated both cell-specific and promoter-dependent transcriptional regulation. A second important region, the OAR (aristaless) domain, which is conserved among 35 Paired-type homeodomain proteins, was observed to inhibit transcription. Deletion of this element resulted in a 20-fold increase of transcription from the tenascin reporter in NIH 3T3 cells but not in C2C12 cells. The OAR domain did not function as a repressor in chimeric fusions with the Gal4 DNA binding domain in either cell type, characterizing it as an inhibitor instead of a repressor. These results give insight into the function of the Prx2 transcription factor while establishing the framework for comparison with the two isoforms of Prx1.

  1. Structure and expression of major histocompatibility complex-binding protein 2, a 275-kDa zinc finger protein that binds to an enhancer of major histocompatibility complex class I genes

    NARCIS (Netherlands)

    Veer, L.J. van 't; Lutz, P.M.; Isselbacher, K.J.; Bernards, R.A.

    1992-01-01

    We have isolated a cDNA encoding a transcription factor that binds to the enhancer of major histocompatibility complex (MHC) class I genes. MHC-binding protein 2 (MBP-2) is a 275-kDa protein, containing two sets of widely separated zinc fingers and a stretch of highly acidic amino acids, a

  2. The iron uptake repressor Fep1 in the fission yeast binds Fe-S cluster through conserved cysteines

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyo-Jin; Lee, Kang-Lok; Kim, Kyoung-Dong; Roe, Jung-Hye, E-mail: jhroe@snu.ac.kr

    2016-09-09

    Iron homeostasis is tightly regulated since iron is an essential but toxic element in the cell. The GATA-type transcription factor Fep1 and its orthologs contribute to iron homeostasis in many fungi by repressing genes for iron uptake when intracellular iron is high. Even though the function and interaction partners of Fep1 have been elucidated extensively In Schizosaccharomyces pombe, the mechanism behind iron-sensing by Fep1 remains elusive. It has been reported that Fep1 interacts with Fe-S-containing monothiol glutaredoxin Grx4 and Grx4-Fra2 complex. In this study, we demonstrate that Fep1 also binds iron, in the form of Fe-S cluster. Spectroscopic and biochemical analyses of as isolated and reconstituted Fep1 suggest that the dimeric Fep1 binds Fe-S clusters. The mutation study revealed that the cluster-binding depended on the conserved cysteines located between the two zinc fingers in the DNA binding domain. EPR analyses revealed [Fe-S]-specific peaks indicative of mixed presence of [2Fe-2S], [3Fe-4S], or [4Fe-4S]. The finding that Fep1 is an Fe-S protein fits nicely with the model that the Fe-S-trafficking Grx4 senses intracellular iron environment and modulates the activity of Fep1. - Highlights: • Fep1, a prototype fungal iron uptake regulator, was isolated stably from Schizosaccharomyces pombe. • Fep1 exhibits UV–visible absorption spectrum, characteristic of [Fe-S] proteins. • The iron and sulfide contents in purified or reconstituted Fep1 also support [Fe-S]. • The conserved cysteines are critical for [Fe-S]-binding. • EPR spectra at 5 K and 123 K suggest a mixed population of [Fe-S].

  3. Investigating the DNA-binding ability of GATA-1-N-terminal zinc finger

    International Nuclear Information System (INIS)

    Wong, R.; Newton, A.; Crossley, M.; Mackay, J.

    2001-01-01

    Erythroid transcription factor GATA-1 interacts with both DNA and other proteins through its zinc finger domains (ZnFs). While it has been known for me time that the C-terminal ZnF binds DNA at GATA sites, only recently has it been observed that the N-terminal finger (NF) is capable of interacting with GATC sites. Further, a number of naturally occurring mutations in NF (V205M, G208S, R216Q, D218G) that lead to anaemia and thrombocytopenia have been identified. We are interested in characterising the NF-DNA interaction and determining the effects of mutation upon this interaction. Using nuclear magnetic resonance (NMR) spectroscopy, we have observed an interaction between recombinant NF and a 16-mer DNA duplex containing a core GATC sequence. This result forms the basis from which residues in NF involved in DNA binding can be identified, and work is being carried out to improve the quality of the NMR data with the aim of determining the solution structure of the NF-DNA complex. The DNA-binding affinity of both wild-type and mutant NFs mentioned above is also being investigated using isothermal titration calorimetry. These data suggest that the strength of the interaction between NF and the 16-mer DNA duplex is in the sub-micromolar range, and comparisons between the DNA-binding affinities of the NF mutants are being made. Together, these studies will help us to understand how GATA-1 acts as a transcriptional regulator and how mutations in NF domain of GATA-1 may lead to blood disorders

  4. Hybrid-Actuated Finger Prosthesis with Tactile Sensing

    Directory of Open Access Journals (Sweden)

    Cheng Yee Low

    2013-10-01

    Full Text Available Finger prostheses are devices developed to emulate the functionality of natural human fingers. On top of their aesthetic appearance in terms of shape, size and colour, such biomimetic devices require a high level of dexterity. They must be capable of gripping an object, and even manipulating it in the hand. This paper presents a biomimetic robotic finger actuated by a hybrid mechanism and integrated with a tactile sensor. The hybrid actuation mechanism comprises a DC micromotor and a Shape Memory Alloy (SMA wire. A customized test rig has been developed to measure the force and stroke produced by the SMA wire. In parallel with the actuator development, experimental investigations have been conducted on Quantum Tunnelling Composite (QTC and Pressure Conductive Rubber (PCR towards the development of a tactile sensor for the finger. The viability of using these materials for tactile sensing has been determined. Such a hybrid actuation approach aided with tactile sensing capability enables a finger design as an integral part of a prosthetic hand for applications up to the transradial amputation level.

  5. Effect of individual finger skin temperature on vibrotactile perception threshold

    Directory of Open Access Journals (Sweden)

    Barbara Harazin

    2013-12-01

    Full Text Available Objectives: In healthy people, the vibrotactile perception threshold (VPT at fingertips depends on a given measurement method and on individual characteristics such as age, gender and finger skin temperature. The aim of the study was to compare the VPT values in 2 groups of healthy subjects with different finger skin temperature. Materials and Methods: The study group comprised 56 males and 76 females, who formed pairs matched with respect to age, gender and body mass index (BMI but differing in terms of finger skin temperature at pre-launch testing. The finger skin temperature of less than 29°C indicated the subjects with "cold hands" and that of more than 29°C, the subjects with "warm hands". The measuring system made use of P8 pallesthesiometer (EMSON-MAT, Poland and the measurement procedure was in compliance with the ISO 13091-1:2001 standard. VPT measurements were performed for the index, middle and ring fingers of both hands at the frequencies of 4 Hz, 25 Hz, 31.5 Hz, 63 Hz, 125 Hz and 250 Hz. Results: The findings of the study revealed that the mean VPTs among the subjects with "cold hands" were significantly higher than the corresponding values among the subjects with "warm hands". Conclusions: The type of individual peripheral thermoregulation should be considered when assessing the VPT and determining its reference values.

  6. Evaluation of electron beam irradiation for disinfection of turmeric fingers

    International Nuclear Information System (INIS)

    Yasumoto, K.; Fujino, M.; Supriyadi; Suzuki, T.; Hayashi, T.

    1991-01-01

    Turmeric finger as one of the most popular spices has been widely used for food manufacturing. However, it has also been a major cause of bacterial infestation of food materials especially in curry, ham and sausage manufacturing. In this study decontamination of bacteria in turmeric finger by electron beam irradiation was evaluated by comparing with several other decontamination methods: i.e., boiling, microwave irradiation, treatment by twin screw extruder and gamma-ray irradiation. By estimation of colony counting on nutrient agar plate, turmeric finger without any treatment gave total viable cell at 10 8 /g. Turmeric finger which was irradiated by electron beam at 10kGy dose dramatically reduced thermotolerant cell population below self restriction level (<1000/g), which has been required by food hygiene law. The same level of sterilization effect was obtained only by gamma-ray irradiation at 10kGy and 20kGy. On the other hand, although treatment through twin screw extruder slightly reduced bacterial numbers, neither boiling nor microwave irradiation gave sufficient decontamination effect on turmeric fingers

  7. Evaluation of electron beam irradiation for disinfection of turmeric fingers

    Energy Technology Data Exchange (ETDEWEB)

    Yasumoto, Kyoden; Fujino, Masayuki; Supriyadi (Kyoto Univ., Uji (Japan). Research Inst. for Food Science); Suzuki, Tetsuya; Hayashi, Toru

    1991-08-01

    Turmeric finger as one of the most popular spices has been widely used for food manufacturing. However, it has also been a major cause of bacterial infestation of food materials especially in curry, ham and sausage manufacturing. In this study decontamination of bacteria in turmeric finger by electron beam irradiation was evaluated by comparing with several other decontamination methods: i.e., boiling, microwave irradiation, treatment by twin screw extruder and gamma-ray irradiation. By estimation of colony counting on nutrient agar plate, turmeric finger without any treatment gave total viable cell at 10{sup 8}/g. Turmeric finger which was irradiated by electron beam at 10 kGy dose dramatically reduced thermotolerant cell population below self restriction level (<1000/g), which has been required by food hygiene law. The same level of sterilization effect was obtained only by gamma-ray irradiation at 10 kGy and 20 kGy. On the other hand, although treatment through twin screw extruder slightly reduced bacterial numbers, neither boiling nor microwave irradiation gave sufficient decontamination effect on turmeric fingers. (author).

  8. Evaluation of electron beam irradiation for disinfection of turmeric fingers

    International Nuclear Information System (INIS)

    Yasumoto, Kyoden; Fujino, Masayuki; Supriyadi; Suzuki, Tetsuya; Hayashi, Toru.

    1991-01-01

    Turmeric finger as one of the most popular spices has been widely used for food manufacturing. However, it has also been a major cause of bacterial infestation of food materials especially in curry, ham and sausage manufacturing. In this study decontamination of bacteria in turmeric finger by electron beam irradiation was evaluated by comparing with several other decontamination methods: i.e., boiling, microwave irradiation, treatment by twin screw extruder and gamma-ray irradiation. By estimation of colony counting on nutrient agar plate, turmeric finger without any treatment gave total viable cell at 10 8 /g. Turmeric finger which was irradiated by electron beam at 10 kGy dose dramatically reduced thermotolerant cell population below self restriction level (<1000/g), which has been required by food hygiene law. The same level of sterilization effect was obtained only by gamma-ray irradiation at 10 kGy and 20 kGy. On the other hand, although treatment through twin screw extruder slightly reduced bacterial numbers, neither boiling nor microwave irradiation gave sufficient decontamination effect on turmeric fingers. (author)

  9. A Method for Recognizing State of Finger Flexure and Extension

    Science.gov (United States)

    Terado, Toshihiko; Fujiwara, Osamu

    In our country, the handicapped and the elderly people in bed increase rapidly. In the bedridden person’s daily life, there may be limitations in the physical movement and the means of mutual communication. For the support of their comfortable daily lives, therefore, the development of human interface equipment becomes an important task. The equipment of this kind is being already developed by means of laser beam, eye-tracking, breathing motion and myo-electric signals, while the attachment and handling are normally not so easy. In this study, paying attention to finger motion, we have developed human interface equipment easily attached to the body, which enables one to measure the finger flexure and extension for mutual communication. The state of finger flexure and extension is identified by a threshold level analysis from the 3D-locus data for the finger movement, which can be measured through the infrared rays from the LED markers attached to a glove with the previously developed prototype system. We then have confirmed from an experiment that nearly 100% recognition for the finger movement can be achieved.

  10. A Simple Negative Interaction in the Positive Transcriptional Feedback of a Single Gene Is Sufficient to Produce Reliable Oscillations

    Science.gov (United States)

    Miró-Bueno, Jesús M.; Rodríguez-Patón, Alfonso

    2011-01-01

    Negative and positive transcriptional feedback loops are present in natural and synthetic genetic oscillators. A single gene with negative transcriptional feedback needs a time delay and sufficiently strong nonlinearity in the transmission of the feedback signal in order to produce biochemical rhythms. A single gene with only positive transcriptional feedback does not produce oscillations. Here, we demonstrate that this single-gene network in conjunction with a simple negative interaction can also easily produce rhythms. We examine a model comprised of two well-differentiated parts. The first is a positive feedback created by a protein that binds to the promoter of its own gene and activates the transcription. The second is a negative interaction in which a repressor molecule prevents this protein from binding to its promoter. A stochastic study shows that the system is robust to noise. A deterministic study identifies that the dynamics of the oscillator are mainly driven by two types of biomolecules: the protein, and the complex formed by the repressor and this protein. The main conclusion of this paper is that a simple and usual negative interaction, such as degradation, sequestration or inhibition, acting on the positive transcriptional feedback of a single gene is a sufficient condition to produce reliable oscillations. One gene is enough and the positive transcriptional feedback signal does not need to activate a second repressor gene. This means that at the genetic level an explicit negative feedback loop is not necessary. The model needs neither cooperative binding reactions nor the formation of protein multimers. Therefore, our findings could help to clarify the design principles of cellular clocks and constitute a new efficient tool for engineering synthetic genetic oscillators. PMID:22205920

  11. The WRKY57 Transcription Factor Affects the Expression of Jasmonate ZIM-Domain Genes Transcriptionally to Compromise Botrytis cinerea Resistance1

    Science.gov (United States)

    Jiang, Yanjuan; Yu, Diqiu

    2016-01-01

    Although necrotrophic pathogens cause many devastating plant diseases, our understanding of the plant defense response to them is limited. Here, we found that loss of function of WRKY57 enhanced the resistance of Arabidopsis (Arabidopsis thaliana) against Botrytis cinerea infection. Further investigation suggested that the negative regulation of WRKY57 against B. cinerea depends on the jasmonic acid (JA) signaling pathway. Chromatin immunoprecipitation experiments revealed that WRKY57 directly binds to the promoters of JASMONATE ZIM-DOMAIN1 (JAZ1) and JAZ5, encoding two important repressors of the JA signaling pathway, and activates their transcription. In vivo and in vitro experiments demonstrated that WRKY57 interacts with nuclear-encoded SIGMA FACTOR BINDING PROTEIN1 (SIB1) and SIB2. Further experiments display that the same domain, the VQ motif, of SIB1 and SIB2 interact with WRKY33 and WRKY57. Moreover, transient transcriptional activity assays confirmed that WRKY57 and WRKY33 competitively regulate JAZ1 and JAZ5, SIB1 and SIB2 further enhance these competitions of WRKY57 to WRKY33. Therefore, coordinated regulation of Arabidopsis against B. cinerea by transcription activators and repressors would benefit plants by allowing fine regulation of defense. PMID:27268959

  12. Cloning and characterization of SmZF1, a gene encoding a Schistosoma mansoni zinc finger protein

    Directory of Open Access Journals (Sweden)

    Souza Paulo R Eleutério de

    2001-01-01

    Full Text Available The zinc finger motifs (Cys2His2 are found in several proteins playing a role in the regulation of transcripton. SmZF1, a Schistosoma mansoni gene encoding a zinc finger protein was initially isolated from an adult worm cDNA library, as a partial cDNA. The full sequence of the gene was obtained by subcloning and sequencing cDNA and genomic fragments. The collated gene sequence is 2181 nt and the complete cDNA sequence is 705 bp containing the full open reading frame of the gene. Analysis of the genome sequence revealed the presence of three introns interrupting the coding region. The open reading frame theoretically encodes a protein of 164 amino acids, with a calculated molecular mass of 18,667Da. The predicted protein contains three zinc finger motifs, usually present in transcription regulatory proteins. PCR amplification with specific primers for the gene allowed for the detection of the target in egg, cercariae, schistosomulum and adult worm cDNA libraries indicating the expression of the mRNA in these life cycle stages of S. mansoni. This pattern of expression suggests the gene plays a role in vital functions of different life cycle stages of the parasite. Future research will be directed to elucidate the functional role of SmZF1.

  13. Prediction of contact forces of underactuated finger by adaptive neuro fuzzy approach

    Science.gov (United States)

    Petković, Dalibor; Shamshirband, Shahaboddin; Abbasi, Almas; Kiani, Kourosh; Al-Shammari, Eiman Tamah

    2015-12-01

    To obtain adaptive finger passive underactuation can be used. Underactuation principle can be used to adapt shapes of the fingers for grasping objects. The fingers with underactuation do not require control algorithm. In this study a kinetostatic model of the underactuated finger mechanism was analyzed. The underactuation is achieved by adding the compliance in every finger joint. Since the contact forces of the finger depend on contact position of the finger and object, it is suitable to make a prediction model for the contact forces in function of contact positions of the finger and grasping objects. In this study prediction of the contact forces was established by a soft computing approach. Adaptive neuro-fuzzy inference system (ANFIS) was applied as the soft computing method to perform the prediction of the finger contact forces.

  14. Dorsal finger texture recognition: Investigating fixed-length SURF

    DEFF Research Database (Denmark)

    Hartung, Daniel; Kückelhahn, Jesper

    2012-01-01

    We seek to create fixed-length features from dorsal finger skin images extracted by the SURF interest point detector to combine it in the privacy enhancing helper data scheme. The source of the biometric samples is the GUC45 database which features finger vein, fingerprint and dorsal finger skin...... images for modality fusion. First, the region of interest (ROI) is extracted, after which SURF features are extracted, and finally two different approaches for creating fixed length feature vectors are applied. SURF performance on the ROI is comparable to the PolyU database reported in the literature...... the complexity of the SURF matching scheme, a reduction in run-time of 75%–80% has been achieved, with only minimal precision loss; EER increases from 0.74% to 1%. The complexity of the matching can be reduced from O(n2) to constant time, but at a higher precision cost and resulting in an EER of 16.51%....

  15. Compensating Pose Uncertainties Through Appropriate Gripper Finger Cutouts

    DEFF Research Database (Denmark)

    Wolniakowski, Adam; Gams, Andrej; Kiforenko, Lilita

    2017-01-01

    capabilities in a sample industrial object grasping scenario for a finger that was designed using an automated simulation-based geometry optimization method [1, 2]. We test the developed gripper with a set of grasps subjected to structured perturbation in a simulation environment and in the real-world setting......The gripper finger design is a recurring problem in many robotic grasping platforms used in industry. The task of switching the gripper configuration to accommodate for a new batch of objects typically requires engineering expertise, and is a lengthy and costly iterative trial-and-error process....... We provide a comparison of the data obtained by using both of these approaches. We argue that the strong correspondence observed in results validates the use of dynamic simulation for the gripper finger design and optimization....

  16. Compensating Pose Uncertainties through Appropriate Gripper Finger Cutouts

    DEFF Research Database (Denmark)

    Wolniakowski, Adam; Gams, Andrej; Kiforenko, Lilita

    2018-01-01

    The gripper finger design is a recurring problem in many robotic grasping platforms used in industry. The task of switching the gripper configuration to accommodate a new batch of objects typically requires engineering expertise and is a lengthy and costly iterative trial-and-error process. One...... in a sample industrial object grasping scenario for a finger that was designed using an automated simulation-based geometry optimization method (Wolniakowski et al., 2013, 2015). We test the developed gripper with a set of grasps subjected to structured perturbation in a simulation environment and in the real......-world setting. We provide a comparison of the data obtained by using both of these approaches. We argue that the strong correspondence observed in results validates the use of dynamic simulation for the gripper finger design and optimization....

  17. Finger dermatoglyphic variations in Rengma Nagas of Nagaland India.

    Science.gov (United States)

    Banik, Sudip Datta; Pal, Paramita; Mukherjee, Deba P

    2009-03-01

    The Rengma Nagas are one of the major Mongoloid tribal populations in the North-Eastern state of Nagaland in India. Population variation and sexual dimorphism in respect of finger dermatoglyphic characteristics in 207 adult individuals (104 males and 103 females) are reported in this present context. Frequency distribution of finger pattern types in different digits (both left and right sides combined) showed that whorls were the most prevalent patterns among both males (52.19%) and females (55.69%), followed by loops (47.70% in males and 42.81% in females). Significant sex differences in Dankmeijer Index (t = 1.47; p dermatoglyphic pattern types, Pattern Intensity Index in fingers, TFRC and AFRC no significant sex differences were observed.

  18. Design of rehabilitation robot hand for fingers CPM training

    Science.gov (United States)

    Zhou, Hongfu; Chan, T. W.; Tong, K. Y.; Kwong, K. K.; Yao, Xifan

    2008-10-01

    This paper presents a low-cost prototype for rehabilitation robot aide patient do hands CPM (continuous passive motion) training. The design of the prototype is based on the principle of Rutgers Master II glove, but it is better in performance for more improvement made. In the design, it uses linear motors to replace pneumatic actuators to make the product more portable and mobile. It increases finger training range to 180 degree for the full range training of hand finger holding and extension. Also the prototype can not only be wearing on palm and fore arm do training for face to face with finger move together, but also be put in the opposite hand glove wear direction for hand rehabilitation training. During the research, Solidworks is used as the tool for mechanical design and movement simulation. It proved through experiment that the prototype made in the research is appropriate for hand do CPM training.

  19. Finger vein recognition based on convolutional neural network

    Directory of Open Access Journals (Sweden)

    Meng Gesi

    2017-01-01

    Full Text Available Biometric Authentication Technology has been widely used in this information age. As one of the most important technology of authentication, finger vein recognition attracts our attention because of its high security, reliable accuracy and excellent performance. However, the current finger vein recognition system is difficult to be applied widely because its complicated image pre-processing and not representative feature vectors. To solve this problem, a finger vein recognition method based on the convolution neural network (CNN is proposed in the paper. The image samples are directly input into the CNN model to extract its feature vector so that we can make authentication by comparing the Euclidean distance between these vectors. Finally, the Deep Learning Framework Caffe is adopted to verify this method. The result shows that there are great improvements in both speed and accuracy rate compared to the previous research. And the model has nice robustness in illumination and rotation.

  20. Trigger finger presenting secondary to leiomyoma: a case report

    Directory of Open Access Journals (Sweden)

    Harb Ziad

    2009-05-01

    Full Text Available Abstract Introduction We present a previously undescribed entity: trigger finger secondary to a leiomyoma. This is the first time such a case has been reported and highlights the fact that common conditions can sometimes present secondary to rare diseases. Case presentation A 39-year-old Caucasian man presented with a fairly typical presentation of trigger finger. During surgical treatment, the lesion was excised and sent for histology, which showed tissue consistent with a leiomyoma. The patient made an uneventful recovery. Conclusion Trigger finger is a common condition that is usually easily diagnosed and managed. However, it is important to appreciate that uncommon conditions, such as leiomyoma, can present with what is sometimes considered trivial disease, and one should always consider the differential diagnoses even when faced with relatively benign conditions.