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Sample records for coactivator gcn5 plays

  1. Subunits of ADA-two-A-containing (ATAC) or Spt-Ada-Gcn5-acetyltrasferase (SAGA) Coactivator Complexes Enhance the Acetyltransferase Activity of GCN5.

    PubMed

    Riss, Anne; Scheer, Elisabeth; Joint, Mathilde; Trowitzsch, Simon; Berger, Imre; Tora, László

    2015-11-27

    Histone acetyl transferases (HATs) play a crucial role in eukaryotes by regulating chromatin architecture and locus specific transcription. GCN5 (KAT2A) is a member of the GNAT (Gcn5-related N-acetyltransferase) family of HATs. In metazoans this enzyme is found in two functionally distinct coactivator complexes, SAGA (Spt Ada Gcn5 acetyltransferase) and ATAC (Ada Two A-containing). These two multiprotein complexes comprise complex-specific and shared subunits, which are organized in functional modules. The HAT module of ATAC is composed of GCN5, ADA2a, ADA3, and SGF29, whereas in the SAGA HAT module ADA2b is present instead of ADA2a. To better understand how the activity of human (h) hGCN5 is regulated in the two related, but different, HAT complexes we carried out in vitro HAT assays. We compared the activity of hGCN5 alone with its activity when it was part of purified recombinant hATAC or hSAGA HAT modules or endogenous hATAC or hSAGA complexes using histone tail peptides and full-length histones as substrates. We demonstrated that the subunit environment of the HAT complexes into which GCN5 incorporates determines the enhancement of GCN5 activity. On histone peptides we show that all the tested GCN5-containing complexes acetylate mainly histone H3K14. Our results suggest a stronger influence of ADA2b as compared with ADA2a on the activity of GCN5. However, the lysine acetylation specificity of GCN5 on histone tails or full-length histones was not changed when incorporated in the HAT modules of ATAC or SAGA complexes. Our results thus demonstrate that the catalytic activity of GCN5 is stimulated by subunits of the ADA2a- or ADA2b-containing HAT modules and is further increased by incorporation of the distinct HAT modules in the ATAC or SAGA holo-complexes. PMID:26468280

  2. Histone acetyltransferase activity of yeast Gcn5p is required for the activation of target genes in vivo

    PubMed Central

    Kuo, Min-Hao; Zhou, Jianxin; Jambeck, Per; Churchill, Mair E.A.; Allis, C. David

    1998-01-01

    Gcn5p is a transcriptional coactivator required for correct expression of various genes in yeast. Several transcriptional regulators, including Gcn5p, possess intrinsic histone acetyltransferase (HAT) activity in vitro. However, whether the HAT activity of any of these proteins is required for gene activation remains unclear. Here, we demonstrate that the HAT activity of Gcn5p is critical for transcriptional activation of target genes in vivo. Core histones are hyperacetylated in cells overproducing functional Gcn5p, and promoters of Gcn5p-regulated genes are associated with hyperacetylated histones upon activation by low-copy Gcn5p. Point mutations within the Gcn5p catalytic domain abolish both promoter-directed histone acetylation and Gcn5p-mediated transcriptional activation. These data provide the first in vivo evidence that promoter-specific histone acetylation, catalyzed by functional Gcn5p, plays a critical role in gene activation. PMID:9499399

  3. The Methionine Transamination Pathway Controls Hepatic Glucose Metabolism through Regulation of the GCN5 Acetyltransferase and the PGC-1α Transcriptional Coactivator.

    PubMed

    Tavares, Clint D J; Sharabi, Kfir; Dominy, John E; Lee, Yoonjin; Isasa, Marta; Orozco, Jose M; Jedrychowski, Mark P; Kamenecka, Theodore M; Griffin, Patrick R; Gygi, Steven P; Puigserver, Pere

    2016-05-13

    Methionine is an essential sulfur amino acid that is engaged in key cellular functions such as protein synthesis and is a precursor for critical metabolites involved in maintaining cellular homeostasis. In mammals, in response to nutrient conditions, the liver plays a significant role in regulating methionine concentrations by altering its flux through the transmethylation, transsulfuration, and transamination metabolic pathways. A comprehensive understanding of how hepatic methionine metabolism intersects with other regulatory nutrient signaling and transcriptional events is, however, lacking. Here, we show that methionine and derived-sulfur metabolites in the transamination pathway activate the GCN5 acetyltransferase promoting acetylation of the transcriptional coactivator PGC-1α to control hepatic gluconeogenesis. Methionine was the only essential amino acid that rapidly induced PGC-1α acetylation through activating the GCN5 acetyltransferase. Experiments employing metabolic pathway intermediates revealed that methionine transamination, and not the transmethylation or transsulfuration pathways, contributed to methionine-induced PGC-1α acetylation. Moreover, aminooxyacetic acid, a transaminase inhibitor, was able to potently suppress PGC-1α acetylation stimulated by methionine, which was accompanied by predicted alterations in PGC-1α-mediated gluconeogenic gene expression and glucose production in primary murine hepatocytes. Methionine administration in mice likewise induced hepatic PGC-1α acetylation, suppressed the gluconeogenic gene program, and lowered glycemia, indicating that a similar phenomenon occurs in vivo These results highlight a communication between methionine metabolism and PGC-1α-mediated hepatic gluconeogenesis, suggesting that influencing methionine metabolic flux has the potential to be therapeutically exploited for diabetes treatment. PMID:27022023

  4. The Gcn4p Activation Domain Interacts Specifically In Vitro with RNA Polymerase II Holoenzyme, TFIID, and the Adap-Gcn5p Coactivator Complex

    PubMed Central

    Drysdale, Connie M.; Jackson, Belinda M.; McVeigh, Richard; Klebanow, Edward R.; Bai, Yu; Kokubo, Tetsuro; Swanson, Mark; Nakatani, Yoshihiro; Weil, P. Anthony; Hinnebusch, Alan G.

    1998-01-01

    The Gcn4p activation domain contains seven clusters of hydrophobic residues that make additive contributions to transcriptional activation in vivo. We observed efficient binding of a glutathione S-transferase (GST)–Gcn4p fusion protein to components of three different coactivator complexes in Saccharomyces cerevisiae cell extracts, including subunits of transcription factor IID (TFIID) (yeast TAFII20 [yTAFII20], yTAFII60, and yTAFII90), the holoenzyme mediator (Srb2p, Srb4p, and Srb7p), and the Adap-Gcn5p complex (Ada2p and Ada3p). The binding to these coactivator subunits was completely dependent on the hydrophobic clusters in the Gcn4p activation domain. Alanine substitutions in single clusters led to moderate reductions in binding, double-cluster substitutions generally led to greater reductions in binding than the corresponding single-cluster mutations, and mutations in four or more clusters reduced binding to all of the coactivator proteins to background levels. The additive effects of these mutations on binding of coactivator proteins correlated with their cumulative effects on transcriptional activation by Gcn4p in vivo, particularly with Ada3p, suggesting that recruitment of these coactivator complexes to the promoter is a cardinal function of the Gcn4p activation domain. As judged by immunoprecipitation analysis, components of the mediator were not associated with constituents of TFIID and Adap-Gcn5p in the extracts, implying that GST-Gcn4p interacted with the mediator independently of these other coactivators. Unexpectedly, a proportion of Ada2p coimmunoprecipitated with yTAFII90, and the yTAFII20, -60, and -90 proteins were coimmunoprecipitated with Ada3p, revealing a stable interaction between components of TFIID and the Adap-Gcn5p complex. Because GST-Gcn4p did not bind specifically to highly purified TFIID, Gcn4p may interact with TFIID via the Adap-Gcn5p complex or some other adapter proteins. The ability of Gcn4p to interact with several distinct

  5. Protein acetylation sites mediated by Schistosoma mansoni GCN5

    SciTech Connect

    Moraes Maciel, Renata de; Furtado Madeiro da Costa, Rodrigo; Meirelles Bastosde Oliveira, Francisco; Rumjanek, Franklin David; Fantappie, Marcelo Rosado

    2008-05-23

    The transcriptional co-activator GCN5, a histone acetyltransferase (HAT), is part of large multimeric complexes that are required for chromatin remodeling and transcription activation. As in other eukaryotes, the DNA from the parasite Schistosome mansoni is organized into nucleosomes and the genome encodes components of chromatin-remodeling complexes. Using a series of synthetic peptides we determined that Lys-14 of histone H3 was acetylated by the recombinant SmGCN5-HAT domain. SmGCN5 was also able to acetylate schistosome non-histone proteins, such as the nuclear receptors SmRXR1 and SmNR1, and the co-activator SmNCoA-62. Electron microscopy revealed the presence of SmGCN5 protein in the nuclei of vitelline cells. Within the nucleus, SmGCN5 was found to be located in interchromatin granule clusters (IGCs), which are transcriptionally active structures. The data suggest that SmGCN5 is involved in transcription activation.

  6. Function and subcellular localization of Gcn5, a histone acetyltransferase in Candida albicans.

    PubMed

    Chang, Peng; Fan, Xueyi; Chen, Jiangye

    2015-08-01

    Candida albicans is an opportunistic fungal pathogen commonly found in humans. It has the ability to switch reversibly between three growth forms: budding yeast, pseudohypha, and hypha. The transition between yeast and hyphal growth forms is critical for the pathogenesis of C. albicans. During the yeast-to-hypha morphologic transition, gene expression is regulated by transcriptional regulators including histone modifying complexes and chromatin remodeling complexes. We previously reported that Esa1, a catalytic subunit in the histone acetyltransferase complex NuA4, is essential for the hyphal development of C. albicans. In this study, we analyzed the functional roles of Gcn5, a catalytic subunit in the histone acetyltransferase complex SAGA, in C. albicans. Gcn5 is required for the invasive and filamentous growth of C. albicans. Deletion of GCN5 impaired hyphal elongation in sensing serum and attenuated the virulence of C. albicans in a mouse systemic infection model. The C. albicans gcn5/gcn5 mutant cells also exhibited sensitivity to cell wall stress. Functional analysis showed that the HAT domain and Bromodomain in Gcn5 play distinct roles in morphogenesis and cell wall stress response of C. albicans. Our results show that the conserved residue Glu188 is crucial for the Gcn5 HAT activity and for Gcn5 function during filamentous growth. In addition, the subcellular distribution of ectopically expressed GFP-Gcn5 correlates with the different growth states of C. albicans. In stationary phase, Gcn5 accumulated in the nucleus, while during vegetative growth it localized in the cytoplasm in a morpha-independent manner. Our results suggest that the nuclear localization of Gcn5 depends on the existence of its N-terminal NLS and HAT domains. PMID:25656079

  7. Gcn5 and SAGA Regulate Shelterin Protein Turnover and Telomere Maintenance

    PubMed Central

    Atanassov, Boyko S.; Evrard, Yvonne A.; Multani, Asha S.; Zhang, Zhijing; Tora, László; Devys, Didier; Chang, Sandy; Dent, Sharon Y.R.

    2009-01-01

    SUMMARY Histone acetyltransferases (HATs) play important roles in gene regulation and DNA repair by influencing the accessibility of chromatin to transcription factors and repair proteins. Here we show that deletion of Gcn5 leads to telomere dysfunction in mouse and human cells. Biochemical studies reveal that depletion of Gcn5 or ubiquitin specific protease 22 (Usp22), which is another bona fide component of the Gcn5-containing SAGA complex, increases ubiquitination and turnover of TRF1, a primary component of the telomeric shelterin complex. Inhibition of the proteasome or over expression of USP22 opposes this effect. The USP22 deubiquitinating module requires association with SAGA complexes for activity, and we find that depletion of Gcn5 compromises this association in mammalian cells. Thus, our results indicate that Gcn5 regulates TRF1 levels through effects on Usp22 activity and SAGA integrity. PMID:19683498

  8. Identification of human proteins functionally conserved with the yeast putative adaptors ADA2 and GCN5.

    PubMed Central

    Candau, R; Moore, P A; Wang, L; Barlev, N; Ying, C Y; Rosen, C A; Berger, S L

    1996-01-01

    Transcriptional adaptor proteins are required for full function of higher eukaryotic acidic activators in the yeast Saccharomyces cerevisiae, suggesting that this pathway of activation is evolutionarily conserved. Consistent with this view, we have identified possible human homologs of yeast ADA2 (yADA2) and yeast GCN5 (yGCN5), components of a putative adaptor complex. While there is overall sequence similarity between the yeast and human proteins, perhaps more significant is conservation of key sequence features with other known adaptors. We show several functional similarities between the human and yeast adaptors. First, as shown for yADA2 and yGCN5, human ADA2 (hADA2) and human GCN5 (hGCN5) interacted in vivo in a yeast two-hybrid assay. Moreover, hGCN5 interacted with yADA2 in this assay, suggesting that the human proteins form similar complexes. Second, both yADA2 and hADA2 contain cryptic activation domains. Third, hGCN5 and yGCN5 had similar stabilizing effects on yADA2 in vivo. Furthermore, the region of yADA2 that interacted with yGCN5 mapped to the amino terminus of yADA2, which is highly conserved in hADA2. Most striking, is the behavior of the human proteins in human cells. First, GAL4-hADA2 activated transcription in HeLa cells, and second, either hADA2 or hGCN5 augmented GAL4-VP16 activation. These data indicated that the human proteins correspond to functional homologs of the yeast adaptors, suggesting that these cofactors play a key role in transcriptional activation. PMID:8552087

  9. Histone acetyltransferase GCN5 is essential for heat stress-responsive gene activation and thermotolerance in Arabidopsis.

    PubMed

    Hu, Zhaorong; Song, Na; Zheng, Mei; Liu, Xinye; Liu, Zhenshan; Xing, Jiewen; Ma, Junhua; Guo, Weiwei; Yao, Yingyin; Peng, Huiru; Xin, Mingming; Zhou, Dao-Xiu; Ni, Zhongfu; Sun, Qixin

    2015-12-01

    Exposure to temperatures exceeding the normal optimum levels, or heat stress (HS), constitutes an environmental disruption for plants, resulting in severe growth and development retardation. Here we show that loss of function of the Arabidopsis histone acetyltransferase GCN5 results in serious defects in terms of thermotolerance, and considerably impairs the transcriptional activation of HS-responsive genes. Notably, expression of several key regulators such as the HS transcription factors HSFA2 and HSFA3, Multiprotein Bridging Factor 1c (MBF1c) and UV-HYPERSENSITIVE 6 (UVH6) is down-regulated in the gcn5 mutant under HS compared with the wild-type. Chromatin immunoprecipitation (ChIP) assays indicated that GCN5 protein is enriched at the promoter regions of HSFA3 and UVH6 genes, but not in HSFA2 and MBF1c, and that GCN5 facilitates H3K9 and H3K14 acetylation, which are associated with HSFA3 and UVH6 activation under HS. Moreover, constitutive expression of UVH6 in the gcn5 mutant partially restores heat tolerance. Taken together, our data indicate that GCN5 plays a key role in the preservation of thermotolerance via versatile regulation in Arabidopsis. In addition, expression of the wheat TaGCN5 gene re-establishes heat tolerance in Arabidopsis gcn5 mutant plants, suggesting that GCN5-mediated thermotolerance may be conserved between Arabidopsis and wheat. PMID:26576681

  10. GCN5 modulates osteogenic differentiation of periodontal ligament stem cells through DKK1 acetylation in inflammatory microenvironment

    PubMed Central

    Li, Bei; Sun, Jin; Dong, Zhiwei; Xue, Peng; He, Xiaoning; Liao, Li; Yuan, Lin; Jin, Yan

    2016-01-01

    Periodontal ligament stem cells (PDLSCs) from periodontitis patients showed defective osteogenic differentiation. However, the mechanism of impaired osteogenic differentiation of PDLSCs in inflammatory microenvironments is still unclear. In this study, we found that inflammation in the microenvironment resulted in downregulation of histone acetyltransferase GCN5 expression and lack of GCN5 caused decreased osteogenic differentiation of PDLSCs. Previous study showed activated Wnt/β-cateinin pathway of PDLSCs resulted in defective osteogenic differentiation. Here we found knockdown of GCN5 decreased the expression of DKK1, an inhibitor of Wnt/β-cateinin pathway, thus activated Wnt/β-catenin pathway of PDLSCs. Mechanistically, GCN5 regulated DKK1 expression by acetylation of Histone H3 lysine 9 (H3K9) and Histone H3 lysine 14 (H3K14) at its promoter region. Interestingly, we found that in vivo injection of aspirin rescued the periodontitis of rats through inhibiting inflammation and upregulating GCN5 expression. Furthermore, aspirin treatment of PDLSCs upregulated GCN5 expression and increased osteogenic differentiation of PDLSCs. In conclusion, GCN5 plays a protective role in periodontitis through acetylation of DKK1 and applying drugs targeting GCN5, such as aspirin, could be a new approach for periodontitis treatment. PMID:27216891

  11. GCN5 modulates osteogenic differentiation of periodontal ligament stem cells through DKK1 acetylation in inflammatory microenvironment.

    PubMed

    Li, Bei; Sun, Jin; Dong, Zhiwei; Xue, Peng; He, Xiaoning; Liao, Li; Yuan, Lin; Jin, Yan

    2016-01-01

    Periodontal ligament stem cells (PDLSCs) from periodontitis patients showed defective osteogenic differentiation. However, the mechanism of impaired osteogenic differentiation of PDLSCs in inflammatory microenvironments is still unclear. In this study, we found that inflammation in the microenvironment resulted in downregulation of histone acetyltransferase GCN5 expression and lack of GCN5 caused decreased osteogenic differentiation of PDLSCs. Previous study showed activated Wnt/β-cateinin pathway of PDLSCs resulted in defective osteogenic differentiation. Here we found knockdown of GCN5 decreased the expression of DKK1, an inhibitor of Wnt/β-cateinin pathway, thus activated Wnt/β-catenin pathway of PDLSCs. Mechanistically, GCN5 regulated DKK1 expression by acetylation of Histone H3 lysine 9 (H3K9) and Histone H3 lysine 14 (H3K14) at its promoter region. Interestingly, we found that in vivo injection of aspirin rescued the periodontitis of rats through inhibiting inflammation and upregulating GCN5 expression. Furthermore, aspirin treatment of PDLSCs upregulated GCN5 expression and increased osteogenic differentiation of PDLSCs. In conclusion, GCN5 plays a protective role in periodontitis through acetylation of DKK1 and applying drugs targeting GCN5, such as aspirin, could be a new approach for periodontitis treatment. PMID:27216891

  12. Quantitating the specificity and selectivity of Gcn5-mediated acetylation of histone H3.

    PubMed

    Kuo, Yin-Ming; Andrews, Andrew J

    2013-01-01

    Lysine acetyltransferases (KATs) play a unique role in regulating gene transcription as well as maintaining the epigenetic state of the cell. KATs such as Gcn5 and p300/CBP can modify multiple residues on a single histone; however, order and specificity of acetylation can be altered by factors such as histone chaperones, subunit proteins or external stimulus. While the importance of acetylation is well documented, it has been difficult to quantitatively measure the specificity and selectivity of acetylation at different residues within a histone. In this paper, we demonstrate a label-free quantitative high throughput mass spectrometry-based assay capable of quantitatively monitoring all known acetylation sites of H3 simultaneously. Using this assay, we are able to analyze the steady-state enzyme kinetics of Gcn5, an evolutionarily conserved KAT. In doing so, we measured Gcn5-mediated acetylation at six residues (K14>K9 ≈ K23> K18> K27 ≈ K36) and the catalytic efficiency (k(cat)/K(m)) for K9, K14, K18, and K23 as well as the nonenzymatic acetylation rate. We observed selectivity differences of up to -4 kcal/mol between K14 and K18, the highest and lowest measurable k(cat)/K(m). These data provide a first look at quantitating the specificity and selectivity of multiple lysines on a single substrate (H3) by Gcn5. PMID:23437046

  13. Acetylation of cyclin-dependent kinase 5 is mediated by GCN5

    SciTech Connect

    Lee, Juhyung; Yun, Nuri; Kim, Chiho; Song, Min-Young; Park, Kang-Sik; Oh, Young J.

    2014-04-25

    Highlights: • Cyclin-dependent kinase 5 (CDK5) is present as an acetylated form. • CDK5 is acetylated by GCN5. • CDK5’s acetylation site is mapped at Lys33. • Its acetylation may affect CDK5’s kinase activity. - Abstract: Cyclin-dependent kinase 5 (CDK5), a member of atypical serine/threonine cyclin-dependent kinase family, plays a crucial role in pathophysiology of neurodegenerative disorders. Its kinase activity and substrate specificity are regulated by several independent pathways including binding with its activator, phosphorylation and S-nitrosylation. In the present study, we report that acetylation of CDK5 comprises an additional posttranslational modification within the cells. Among many candidates, we confirmed that its acetylation is enhanced by GCN5, a member of the GCN5-related N-acetyl-transferase family of histone acetyltransferase. Co-immunoprecipitation assay and fluorescent localization study indicated that GCN5 physically interacts with CDK5 and they are co-localized at the specific nuclear foci. Furthermore, liquid chromatography in conjunction with a mass spectrometry indicated that CDK5 is acetylated at Lys33 residue of ATP binding domain. Considering this lysine site is conserved among a wide range of species and other related cyclin-dependent kinases, therefore, we speculate that acetylation may alter the kinase activity of CDK5 via affecting efficacy of ATP coordination.

  14. Members of the GCN5 histone acetyltransferase complex regulate PLETHORA-mediated root stem cell niche maintenance and transit amplifying cell proliferation in Arabidopsis.

    PubMed

    Kornet, Noortje; Scheres, Ben

    2009-04-01

    The PLETHORA (PLT) stem cell transcription factors form a developmentally instructive protein gradient in Arabidopsis thaliana roots. Histone acetylation is known to facilitate gene transcription and plays an important role in developmental processes. Here, we show that histone acetyltransferase GCN5 (for general control nonderepressible 5) attenuates the PLT gradient. Based on genetic evidence, we establish that GCN5 is essential for root stem cell niche maintenance and acts in the PLT pathway. The GCN5-associated factor ADA2b (for alteration/deficiency in activation 2b) is also positioned in the PLT pathway and regulates PLT expression, similar to GCN5. Both GCN5 and ADA2b mediate proliferation of the transit amplifying cells, but ADA2b does not affect stem cell niche maintenance. Overexpression of PLT2 rescues the stem cell niche defect of gcn5 mutants, indicating that GCN5 regulation of PLT expression is essential for maintenance of the root stem cell niche. We conclude that histone acetylation complexes play an important role in shaping a developmentally instructive gradient in the root. PMID:19376933

  15. Members of the GCN5 Histone Acetyltransferase Complex Regulate PLETHORA-Mediated Root Stem Cell Niche Maintenance and Transit Amplifying Cell Proliferation in Arabidopsis[W

    PubMed Central

    Kornet, Noortje; Scheres, Ben

    2009-01-01

    The PLETHORA (PLT) stem cell transcription factors form a developmentally instructive protein gradient in Arabidopsis thaliana roots. Histone acetylation is known to facilitate gene transcription and plays an important role in developmental processes. Here, we show that histone acetyltransferase GCN5 (for general control nonderepressible 5) attenuates the PLT gradient. Based on genetic evidence, we establish that GCN5 is essential for root stem cell niche maintenance and acts in the PLT pathway. The GCN5-associated factor ADA2b (for alteration/deficiency in activation 2b) is also positioned in the PLT pathway and regulates PLT expression, similar to GCN5. Both GCN5 and ADA2b mediate proliferation of the transit amplifying cells, but ADA2b does not affect stem cell niche maintenance. Overexpression of PLT2 rescues the stem cell niche defect of gcn5 mutants, indicating that GCN5 regulation of PLT expression is essential for maintenance of the root stem cell niche. We conclude that histone acetylation complexes play an important role in shaping a developmentally instructive gradient in the root. PMID:19376933

  16. Multivalent binding of p53 to the STAGA complex mediates coactivator recruitment after UV damage.

    PubMed

    Gamper, Armin M; Roeder, Robert G

    2008-04-01

    The recruitment of transcriptional coactivators, including histone modifying enzymes, is an important step in transcription regulation. A typical activator is thought to interact with several cofactors, presumably in a sequential manner. The common use of several cofactors raises the question of how activators achieve both cofactor selectivity and diversity. Human STAGA is a multiprotein complex with the acetyltransferase GCN5L as the catalytic subunit. Here, we first show, through RNA interference-mediated knock-down and chromatin immunoprecipitation assays, that GCN5 plays a role in p53-dependent gene activation. We then employ p53 mutagenesis, in vitro binding, protein-protein cross-linking, and chromatin immunoprecipitation assays to establish a novel role for the second p53 activation subdomain (AD2) in STAGA recruitment and, further, to demonstrate that optimal binding of STAGA to p53 involves interactions of STAGA subunits TAF9, GCN5, and ADA2b, respectively, with AD1, AD2, and carboxy-terminal domains of p53. These results provide concrete evidence for mediation of transcription factor binding to coactivator complexes through multiple interactions. Based on our data, we propose a cooperative and modular binding mode for the recruitment of coactivator complexes to promoters. PMID:18250150

  17. Structural basis for acyl-group discrimination by human Gcn5L2

    PubMed Central

    Ringel, Alison E.; Wolberger, Cynthia

    2016-01-01

    Gcn5 is a conserved acetyltransferase that regulates transcription by acetylating the N-terminal tails of histones. Motivated by recent studies identifying a chemically diverse array of lysine acyl modifications in vivo, the acyl-chain specificity of the acetyltransferase human Gcn5 (Gcn5L2) was examined. Whereas Gcn5L2 robustly catalyzes lysine acetylation, the acyltransferase activity of Gcn5L2 becomes progressively weaker with increasing acyl-chain length. To understand how Gcn5 discriminates between different acyl-CoA molecules, structures of the catalytic domain of human Gcn5L2 bound to propionyl-CoA and butyryl-CoA were determined. Although the active site of Gcn5L2 can accommodate propionyl-CoA and butyryl-CoA without major structural rearrangements, butyryl-CoA adopts a conformation incompatible with catalysis that obstructs the path of the incoming lysine residue and acts as a competitive inhibitor of Gcn5L2 versus acetyl-CoA. These structures demonstrate how Gcn5L2 discriminates between acyl-chain donors and explain why Gcn5L2 has weak activity for acyl moieties that are larger than an acetyl group. PMID:27377381

  18. NUCLEOPHOSMIN/B23 NEGATIVELY REGULATES GCN5-DEPENDENT HISTONE ACETYLATION AND TRANSACTIVATION

    SciTech Connect

    Zou, Yonglong; Wu, Jun; Giannone, Richard J; Boucher, Lorrie; Du, Hansen; Huang, Ying; Johnson, Dabney K; Liu, Yie; Wang, Yisong

    2007-01-01

    Nucleophosmin/B23 is a multifunctional phosphoprotein that is overexpressed in cancer cells and has been shown to be involved in both positive and negative regulation of transcription. In this study, we first identified GCN5 acetyltransferase as a B23-interacting protein by mass spectrometry, which was then confirmed by in vivo co-immunoprecipitation. In vitro assay demonstrated that B23 bound the PCAF-N domain of GCN5 and inhibited GCN5-mediated acetylation of both free and mononucleosomal histones, probably through interfering with GCN5 and masking histones from being acetylated. Mitotic B23 exhibited higher inhibitory activity on GCN5-mediated histone acetylation than interphase B23. Immunodepletion experiments of mitotic extracts revealed that phosphorylation of B23 at Thr199 enhanced the inhibition of GCN5-mediated histone acetylation. Moreover, luciferase reporter and microarray analyses suggested that B23 attenuated GCN5-mediated transactivation in vivo. Taken together, our studies suggest a molecular mechanism of B23 in the mitotic inhibition of GCN5-mediated histone acetylation and transactivation.

  19. Functional similarity and physical association between GCN5 and ADA2: putative transcriptional adaptors.

    PubMed Central

    Marcus, G A; Silverman, N; Berger, S L; Horiuchi, J; Guarente, L

    1994-01-01

    A selection for yeast mutants resistant to GAL4-VP16-induced toxicity previously identified two genes, ADA2 and ADA3, which may function as adaptors for some transcriptional activation domains and thereby facilitate activation. Here we identify two new genes by the same selection, one of which is identical to GCN5. We show that gcn5 mutants share properties with ada mutants, including slow growth, temperature sensitivity and reduced activation by the VP16 and GCN4 activation domains. Double mutant studies suggest that ADA2 and GCN5 function together in a complex or pathway. Moreover, we demonstrate that GCN5 binds to ADA2 both by the two-hybrid assay in vivo and by co-immunoprecipitation in vitro. This suggests that ADA2 and GCN5 are part of a heteromeric complex that mediates transcriptional activation. Finally, we demonstrate the functional importance of the bromodomain of GCN5, a sequence found in other global transcription factors such as the SWI/SNF complex and the TATA binding protein-associated factors. This domain is not required for the interaction between GCN5 and ADA2 and thus may mediate a more general activity of transcription factors. Images PMID:7957049

  20. Essential Functional Interactions of Saga, a Saccharomyces Cerevisiae Complex of Spt, Ada, and Gcn5 Proteins, with the Snf/Swi and Srb/Mediator Complexes

    PubMed Central

    Roberts, S. M.; Winston, F.

    1997-01-01

    The Saccharomyces cerevisiae transcription factor Spt20/Ada5 was originally identified by mutations that suppress Ty insertion alleles and by mutations that suppress the toxicity caused by Gal4-VP16 overexpression. Here we present evidence for physical associations between Spt20/Ada5 and three other Spt proteins, suggesting that they exist in a complex. A related study demonstrates that this complex also contains the histone acetyltransferase, Gcn5, and Ada2. This complex has been named SAGA (Spt/Ada/Gcn5 acetyltransferase). To identify functions that genetically interact with SAGA, we have screened for mutations that cause lethality in an spt20Δ/ada5Δ mutant. Our screen identified mutations in SNF2, SIN4, and GAL11. These mutations affect two known transcription complexes: Snf/Swi, which functions in nucleosome remodeling, and Srb/mediator, which is required for regulated transcription by RNA polymerase II. Systematic analysis has demonstrated that spt20Δ/ada5Δand spt7Δ mutations cause lethality with every snf/swi and srb/mediator mutation tested. Furthermore, a gcn5Δ mutation causes severe sickness with snf/swi mutations, but not with srb/mediator mutations. These findings suggest that SAGA has multiple activities and plays critical roles in transcription by RNA polymerase II. PMID:9335585

  1. Synergistic action of histone acetyltransferase GCN5 and receptor CLAVATA1 negatively affects ethylene responses in Arabidopsis thaliana.

    PubMed

    Poulios, Stylianos; Vlachonasios, Konstantinos E

    2016-02-01

    GENERAL CONTROL NON-REPRESSIBLE 5 (GCN5) is a histone acetyltransferase (HAT) and the catalytic subunit of several multicomponent HAT complexes that acetylate lysine residues of histone H3. Mutants in AtGCN5 display pleiotropic developmental defects including aberrant meristem function. Shoot apical meristem (SAM) maintenance is regulated by CLAVATA1 (CLV1), a receptor kinase that controls the size of the shoot and floral meristems. Upon activation through CLV3 binding, CLV1 signals to the transcription factor WUSCHEL (WUS), restricting WUS expression and thus the meristem size. We hypothesized that GCN5 and CLV1 act together to affect SAM function. Using genetic and molecular approaches, we generated and characterized clv gcn5 mutants. Surprisingly, the clv1-1 gcn5-1 double mutant exhibited constitutive ethylene responses, suggesting that GCN5 and CLV signaling act synergistically to inhibit ethylene responses in Arabidopsis. This genetic and molecular interaction was mediated by ETHYLENE INSENSITIVE 3/ EIN3-LIKE1 (EIN3/EIL1) transcription factors. Our data suggest that signals from the CLV transduction pathway reach the GCN5-containing complexes in the nucleus and alter the histone acetylation status of ethylene-responsive genes, thus translating the CLV information to transcriptional activity and uncovering a link between histone acetylation and SAM maintenance in the complex mode of ethylene signaling. PMID:26596766

  2. DNA Binding by Sgf11 Protein Affects Histone H2B Deubiquitination by Spt-Ada-Gcn5-Acetyltransferase (SAGA)*

    PubMed Central

    Koehler, Christian; Bonnet, Jacques; Stierle, Matthieu; Romier, Christophe; Devys, Didier; Kieffer, Bruno

    2014-01-01

    The yeast Spt-Ada-Gcn5-acetyltransferase (SAGA) complex is a transcription coactivator that contains a histone H2B deubiquitination activity mediated by its Ubp8 subunit. Full enzymatic activity requires the formation of a quaternary complex, the deubiquitination module (DUBm) of SAGA, which is composed of Ubp8, Sus1, Sgf11, and Sgf73. The crystal structures of the DUBm have shed light on the structure/function relationship of this complex. Specifically, both Sgf11 and Sgf73 contain zinc finger domains (ZnF) that appear essential for the DUBm activity. Whereas Sgf73 N-terminal ZnF is important for DUBm stability, Sgf11 C-terminal ZnF appears to be involved in DUBm function. To further characterize the role of these two zinc fingers, we have solved their structure by NMR. We show that, contrary to the previously reported structures, Sgf73 ZnF adopts a C2H2 coordination with unusual tautomeric forms for the coordinating histidines. We further report that the Sgf11 ZnF, but not the Sgf73 ZnF, binds to nucleosomal DNA with a binding interface composed of arginine residues located within the ZnF α-helix. Mutational analyses both in vitro and in vivo provide evidence for the functional relevance of our structural observations. The combined interpretation of our results leads to an uncommon ZnF-DNA interaction between the SAGA DUBm and nucleosomes, thus providing further functional insights into SAGA's epigenetic modulation of the chromatin structure. PMID:24509845

  3. Genome-wide cooperation by HAT Gcn5, remodeler SWI/SNF, and chaperone Ydj1 in promoter nucleosome eviction and transcriptional activation.

    PubMed

    Qiu, Hongfang; Chereji, Răzvan V; Hu, Cuihua; Cole, Hope A; Rawal, Yashpal; Clark, David J; Hinnebusch, Alan G

    2016-02-01

    Chaperones, nucleosome remodeling complexes, and histone acetyltransferases have been implicated in nucleosome disassembly at promoters of particular yeast genes, but whether these cofactors function ubiquitously, as well as the impact of nucleosome eviction on transcription genome-wide, is poorly understood. We used chromatin immunoprecipitation of histone H3 and RNA polymerase II (Pol II) in mutants lacking single or multiple cofactors to address these issues for about 200 genes belonging to the Gcn4 transcriptome, of which about 70 exhibit marked reductions in H3 promoter occupancy on induction by amino acid starvation. Examining four target genes in a panel of mutants indicated that SWI/SNF, Gcn5, the Hsp70 cochaperone Ydj1, and chromatin-associated factor Yta7 are required downstream from Gcn4 binding, whereas Asf1/Rtt109, Nap1, RSC, and H2AZ are dispensable for robust H3 eviction in otherwise wild-type cells. Using ChIP-seq to interrogate all 70 exemplar genes in single, double, and triple mutants implicated Gcn5, Snf2, and Ydj1 in H3 eviction at most, but not all, Gcn4 target promoters, with Gcn5 generally playing the greatest role and Ydj1 the least. Remarkably, these three cofactors cooperate similarly in H3 eviction at virtually all yeast promoters. Defective H3 eviction in cofactor mutants was coupled with reduced Pol II occupancies for the Gcn4 transcriptome and the most highly expressed uninduced genes, but the relative Pol II levels at most genes were unaffected or even elevated. These findings indicate that nucleosome eviction is crucial for robust transcription of highly expressed genes but that other steps in gene activation are more rate-limiting for most other yeast genes. PMID:26602697

  4. Autoregulation of the Rsc4 Tandem Bromodomain by Gcn5 Acetylation

    SciTech Connect

    VanDemark,A.; Kasten, M.; Ferris, E.; Heroux, A.; Hill, C.; Cairns, B.

    2007-01-01

    An important issue for chromatin remodeling complexes is how their bromodomains recognize particular acetylated lysine residues in histones. The Rsc4 subunit of the yeast remodeler RSC contains an essential tandem bromodomain (TBD) that binds acetylated K14 of histone H3 (H3K14ac). We report a series of crystal structures that reveal a compact TBD that binds H3K14ac in the second bromodomain and, remarkably, binds acetylated K25 of Rsc4 itself in the first bromodomain. Endogenous Rsc4 is acetylated only at K25, and Gcn5 is identified as necessary and sufficient for Rsc4 K25 acetylation in vivo and in vitro. Rsc4 K25 acetylation inhibits binding to H3K14ac, and mutation of Rsc4 K25 results in altered growth rates. These data suggest an autoregulatory mechanism in which Gcn5 performs both the activating (H3K14ac) and inhibitory (Rsc4 K25ac) modifications, perhaps to provide temporal regulation. Additional regulatory mechanisms are indicated as H3S10 phosphorylation inhibits Rsc4 binding to H3K14ac peptides.

  5. Acetylome Profiling Reveals Overlap in the Regulation of Diverse Processes by Sirtuins, Gcn5, and Esa1*

    PubMed Central

    Downey, Michael; Johnson, Jeffrey R.; Davey, Norman E.; Newton, Billy W.; Johnson, Tasha L.; Galaang, Shastyn; Seller, Charles A.; Krogan, Nevan; Toczyski, David P.

    2015-01-01

    Although histone acetylation and deacetylation machineries (HATs and HDACs) regulate important aspects of cell function by targeting histone tails, recent work highlights that non-histone protein acetylation is also pervasive in eukaryotes. Here, we use quantitative mass-spectrometry to define acetylations targeted by the sirtuin family, previously implicated in the regulation of non-histone protein acetylation. To identify HATs that promote acetylation of these sites, we also performed this analysis in gcn5 (SAGA) and esa1 (NuA4) mutants. We observed strong sequence specificity for the sirtuins and for each of these HATs. Although the Gcn5 and Esa1 consensus sequences are entirely distinct, the sirtuin consensus overlaps almost entirely with that of Gcn5, suggesting a strong coordination between these two regulatory enzymes. Furthermore, by examining global acetylation in an ada2 mutant, which dissociates Gcn5 from the SAGA complex, we found that a subset of Gcn5 targets did not depend on an intact SAGA complex for targeting. Our work provides a framework for understanding how HAT and HDAC enzymes collaborate to regulate critical cellular processes related to growth and division. PMID:25381059

  6. PGC-1α Serine 570 Phosphorylation and GCN5-mediated Acetylation by Angiotensin II Drive Catalase Down-regulation and Vascular Hypertrophy*

    PubMed Central

    Xiong, Shiqin; Salazar, Gloria; San Martin, Alejandra; Ahmad, Mushtaq; Patrushev, Nikolay; Hilenski, Lula; Nazarewicz, Rafal Robert; Ma, Minhui; Ushio-Fukai, Masuko; Alexander, R. Wayne

    2010-01-01

    Angiotensin II (Ang II) is a pleuripotential hormone that is important in the pathophysiology of multiple conditions including aging, cardiovascular and renal diseases, and insulin resistance. Reactive oxygen species (ROS) are important mediators of Ang II-induced signaling generally and have a well defined role in vascular hypertrophy, which is inhibited by overexpression of catalase, inferring a specific role of H2O2. The molecular mechanisms are understood incompletely. The transcriptional coactivator peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) is a key regulator of energy metabolism and ROS-scavenging enzymes including catalase. We show that Ang II stimulates Akt-dependent PGC-1α serine 570 phosphorylation, which is required for the binding of the histone acetyltransferase GCN5 (general control nonderepressible 5) to PGC-1α and for its lysine acetylation. These sequential post-translational modifications suppress PGC-1α activity and prevent its binding to the catalase promoter through the forkhead box O1 transcription factor, thus decreasing catalase expression. We demonstrate that overexpression of the phosphorylation-defective mutant PGC-1α (S570A) prevents Ang II-induced increases in H2O2 levels and hypertrophy ([3H]leucine incorporation). Knockdown of PGC-1α by small interfering RNA promotes basal and Ang II-stimulated ROS and hypertrophy, which is reversed by polyethylene glycol-conjugated catalase. Thus, endogenous PGC-1α is a negative regulator of vascular hypertrophy by up-regulating catalase expression and thus reducing ROS levels. We provide novel mechanistic insights by which Ang II may mediate its ROS-dependent pathophysiologic effects on multiple cardiometabolic diseases. PMID:19940161

  7. The p23 molecular chaperone and GCN5 acetylase jointly modulate protein-DNA dynamics and open chromatin status

    PubMed Central

    Zelin, Elena; Zhang, Yang; Toogun, Oyetunji A.; Zhong, Sheng; Freeman, Brian C.

    2012-01-01

    SUMMARY Cellular processes function through multi-step pathways that are reliant on the controlled association and disassociation of sequential protein complexes. While dynamic action is critical to propagate and terminate work, the mechanisms used to disassemble biological structures are not fully understood. Here, we show that the p23 molecular chaperone initiates disassembly of protein-DNA complexes and that the GCN5 acetyltransferase prolongs the dissociated state through lysine acetylation. By modulating the DNA bound-state, we found that the conserved and essential joint activities of p23 and GCN5 impacted transcription factor activation potential and response time to an environmental cue. Notably, p23 and GCN5 were required to maintain open chromatin regions along the genome indicating that dynamic protein behavior is a critical feature of various DNA-associated events. Our data support a model in which p23 and GCN5 regulate diverse multi-step pathways by controlling the longevity of protein-DNA complexes. PMID:23022381

  8. Spt-Ada-Gcn5-Acetyltransferase (SAGA) Complex in Plants: Genome Wide Identification, Evolutionary Conservation and Functional Determination

    PubMed Central

    Srivastava, Rakesh; Rai, Krishan Mohan; Pandey, Bindu; Singh, Sudhir P.; Sawant, Samir V.

    2015-01-01

    The recruitment of RNA polymerase II on a promoter is assisted by the assembly of basal transcriptional machinery in eukaryotes. The Spt-Ada-Gcn5-Acetyltransferase (SAGA) complex plays an important role in transcription regulation in eukaryotes. However, even in the advent of genome sequencing of various plants, SAGA complex has been poorly defined for their components and roles in plant development and physiological functions. Computational analysis of Arabidopsis thaliana and Oryza sativa genomes for SAGA complex resulted in the identification of 17 to 18 potential candidates for SAGA subunits. We have further classified the SAGA complex based on the conserved domains. Phylogenetic analysis revealed that the SAGA complex proteins are evolutionary conserved between plants, yeast and mammals. Functional annotation showed that they participate not only in chromatin remodeling and gene regulation, but also in different biological processes, which could be indirect and possibly mediated via the regulation of gene expression. The in silico expression analysis of the SAGA components in Arabidopsis and O. sativa clearly indicates that its components have a distinct expression profile at different developmental stages. The co-expression analysis of the SAGA components suggests that many of these subunits co-express at different developmental stages, during hormonal interaction and in response to stress conditions. Quantitative real-time PCR analysis of SAGA component genes further confirmed their expression in different plant tissues and stresses. The expression of representative salt, heat and light inducible genes were affected in mutant lines of SAGA subunits in Arabidopsis. Altogether, the present study reveals expedient evidences of involvement of the SAGA complex in plant gene regulation and stress responses. PMID:26263547

  9. Deposition of 5-Methylcytosine on Enhancer RNAs Enables the Coactivator Function of PGC-1α.

    PubMed

    Aguilo, Francesca; Li, SiDe; Balasubramaniyan, Natarajan; Sancho, Ana; Benko, Sabina; Zhang, Fan; Vashisht, Ajay; Rengasamy, Madhumitha; Andino, Blanca; Chen, Chih-hung; Zhou, Felix; Qian, Chengmin; Zhou, Ming-Ming; Wohlschlegel, James A; Zhang, Weijia; Suchy, Frederick J; Walsh, Martin J

    2016-01-26

    The Peroxisome proliferator-activated receptor-gamma coactivator 1 alpha (PGC-1α) is a transcriptional co-activator that plays a central role in adapted metabolic responses. PGC-1α is dynamically methylated and unmethylated at the residue K779 by the methyltransferase SET7/9 and the Lysine Specific Demethylase 1A (LSD1), respectively. Interactions of methylated PGC-1α[K779me] with the Spt-Ada-Gcn5-acetyltransferase (SAGA) complex, the Mediator members MED1 and MED17, and the NOP2/Sun RNA methytransferase 7 (NSUN7) reinforce transcription, and are concomitant with the m(5)C mark on enhancer RNAs (eRNAs). Consistently, loss of Set7/9 and NSun7 in liver cell model systems resulted in depletion of the PGC-1α target genes Pfkl, Sirt5, Idh3b, and Hmox2, which was accompanied by a decrease in the eRNAs levels associated with these loci. Enrichment of m(5)C within eRNA species coincides with metabolic stress of fasting in vivo. Collectively, these findings illustrate the complex epigenetic circuitry imposed by PGC-1α at the eRNA level to fine-tune energy metabolism. PMID:26774474

  10. DEPOSITION OF 5-METHYLCYTOSINE ON ENHANCER RNAs ENABLES THE COACTIVATOR FUNCTION OF PGC-1α

    PubMed Central

    Aguilo, Francesca; Li, SiDe; Balasubramaniyan, Natarajan; Sancho, Ana; Benko, Sabina; Zhang, Fan; Vashisht, Ajay; Rengasamy, Madhumitha; Andino, Blanca; Chen, Chih-hung; Zhou, Felix; Qian, Chengmin; Zhou, Ming-Ming; Wohlschlegel, James A.; Zhang, Weijia; Suchy, Frederick J.; Walsh, Martin J.

    2015-01-01

    SUMMARY The Peroxisome proliferator-activated receptor-gamma coactivator 1 alpha (PGC-1α) is a transcriptional co-activator that plays a central role in adapted metabolic responses. PGC-1α is dynamically methylated and unmethylated at the residue K779 by the methyltransferase SET7/9 and the Lysine Specific Demethylase 1A (LSD1), respectively. Interactions of methylated PGC-1α[K779me] with the Spt-Ada-Gcn5-acetyltransferase (SAGA) complex, the Mediator members MED1 and MED17, and the NOP2/Sun RNA methytransferase 7 (NSUN7) reinforce transcription, and are concomitant with the m5C mark on enhancer RNAs (eRNAs). Consistently, loss of Set7/9 and NSun7 in liver cell model systems resulted in depletion of the PGC-1α target genes Pfkl, Sirt5, Idh3b and Hmox2, which was accompanied with a decrease in the eRNAs levels associated to these loci. Enrichment of m5C within eRNA species coincides with metabolic stress of fasting in vivo. Collectively, these findings illustrate the complex epigenetic circuitry imposed by PGC-1α at the eRNA level to fine-tune energy metabolism. PMID:26774474

  11. Conformational flexibility and subunit arrangement of the modular yeast Spt-Ada-Gcn5 acetyltransferase complex.

    PubMed

    Setiaputra, Dheva; Ross, James D; Lu, Shan; Cheng, Derrick T; Dong, Meng-Qiu; Yip, Calvin K

    2015-04-17

    The Spt-Ada-Gcn5 acetyltransferase (SAGA) complex is a highly conserved, 19-subunit histone acetyltransferase complex that activates transcription through acetylation and deubiquitination of nucleosomal histones in Saccharomyces cerevisiae. Because SAGA has been shown to display conformational variability, we applied gradient fixation to stabilize purified SAGA and systematically analyzed this flexibility using single-particle EM. Our two- and three-dimensional studies show that SAGA adopts three major conformations, and mutations of specific subunits affect the distribution among these. We also located the four functional modules of SAGA using electron microscopy-based labeling and transcriptional activator binding analyses and show that the acetyltransferase module is localized in the most mobile region of the complex. We further comprehensively mapped the subunit interconnectivity of SAGA using cross-linking mass spectrometry, revealing that the Spt and Taf subunits form the structural core of the complex. These results provide the necessary restraints for us to generate a model of the spatial arrangement of all SAGA subunits. According to this model, the chromatin-binding domains of SAGA are all clustered in one face of the complex that is highly flexible. Our results relate information of overall SAGA structure with detailed subunit level interactions, improving our understanding of its architecture and flexibility. PMID:25713136

  12. Structure and Functional Diversity of GCN5-Related N-Acetyltransferases (GNAT).

    PubMed

    Salah Ud-Din, Abu Iftiaf Md; Tikhomirova, Alexandra; Roujeinikova, Anna

    2016-01-01

    General control non-repressible 5 (GCN5)-related N-acetyltransferases (GNAT) catalyze the transfer of an acyl moiety from acyl coenzyme A (acyl-CoA) to a diverse group of substrates and are widely distributed in all domains of life. This review of the currently available data acquired on GNAT enzymes by a combination of structural, mutagenesis and kinetic methods summarizes the key similarities and differences between several distinctly different families within the GNAT superfamily, with an emphasis on the mechanistic insights obtained from the analysis of the complexes with substrates or inhibitors. It discusses the structural basis for the common acetyltransferase mechanism, outlines the factors important for the substrate recognition, and describes the mechanism of action of inhibitors of these enzymes. It is anticipated that understanding of the structural basis behind the reaction and substrate specificity of the enzymes from this superfamily can be exploited in the development of novel therapeutics to treat human diseases and combat emerging multidrug-resistant microbial infections. PMID:27367672

  13. Conformational Flexibility and Subunit Arrangement of the Modular Yeast Spt-Ada-Gcn5 Acetyltransferase Complex*

    PubMed Central

    Setiaputra, Dheva; Ross, James D.; Lu, Shan; Cheng, Derrick T.; Dong, Meng-Qiu; Yip, Calvin K.

    2015-01-01

    The Spt-Ada-Gcn5 acetyltransferase (SAGA) complex is a highly conserved, 19-subunit histone acetyltransferase complex that activates transcription through acetylation and deubiquitination of nucleosomal histones in Saccharomyces cerevisiae. Because SAGA has been shown to display conformational variability, we applied gradient fixation to stabilize purified SAGA and systematically analyzed this flexibility using single-particle EM. Our two- and three-dimensional studies show that SAGA adopts three major conformations, and mutations of specific subunits affect the distribution among these. We also located the four functional modules of SAGA using electron microscopy-based labeling and transcriptional activator binding analyses and show that the acetyltransferase module is localized in the most mobile region of the complex. We further comprehensively mapped the subunit interconnectivity of SAGA using cross-linking mass spectrometry, revealing that the Spt and Taf subunits form the structural core of the complex. These results provide the necessary restraints for us to generate a model of the spatial arrangement of all SAGA subunits. According to this model, the chromatin-binding domains of SAGA are all clustered in one face of the complex that is highly flexible. Our results relate information of overall SAGA structure with detailed subunit level interactions, improving our understanding of its architecture and flexibility. PMID:25713136

  14. Structure and Functional Diversity of GCN5-Related N-Acetyltransferases (GNAT)

    PubMed Central

    Salah Ud-Din, Abu Iftiaf Md; Tikhomirova, Alexandra; Roujeinikova, Anna

    2016-01-01

    General control non-repressible 5 (GCN5)-related N-acetyltransferases (GNAT) catalyze the transfer of an acyl moiety from acyl coenzyme A (acyl-CoA) to a diverse group of substrates and are widely distributed in all domains of life. This review of the currently available data acquired on GNAT enzymes by a combination of structural, mutagenesis and kinetic methods summarizes the key similarities and differences between several distinctly different families within the GNAT superfamily, with an emphasis on the mechanistic insights obtained from the analysis of the complexes with substrates or inhibitors. It discusses the structural basis for the common acetyltransferase mechanism, outlines the factors important for the substrate recognition, and describes the mechanism of action of inhibitors of these enzymes. It is anticipated that understanding of the structural basis behind the reaction and substrate specificity of the enzymes from this superfamily can be exploited in the development of novel therapeutics to treat human diseases and combat emerging multidrug-resistant microbial infections. PMID:27367672

  15. Promotion of Cell Viability and Histone Gene Expression by the Acetyltransferase Gcn5 and the Protein Phosphatase PP2A in Saccharomyces cerevisiae.

    PubMed

    Petty, Emily L; Lafon, Anne; Tomlinson, Shannon L; Mendelsohn, Bryce A; Pillus, Lorraine

    2016-08-01

    Histone modifications direct chromatin-templated events in the genome and regulate access to DNA sequence information. There are multiple types of modifications, and a common feature is their dynamic nature. An essential step for understanding their regulation, therefore, lies in characterizing the enzymes responsible for adding and removing histone modifications. Starting with a dosage-suppressor screen in Saccharomyces cerevisiae, we have discovered a functional interaction between the acetyltransferase Gcn5 and the protein phosphatase 2A (PP2A) complex, two factors that regulate post-translational modifications. We find that RTS1, one of two genes encoding PP2A regulatory subunits, is a robust and specific high-copy suppressor of temperature sensitivity of gcn5∆ and a subset of other gcn5∆ phenotypes. Conversely, loss of both PP2A(Rts1) and Gcn5 function in the SAGA and SLIK/SALSA complexes is lethal. RTS1 does not restore global transcriptional defects in gcn5∆; however, histone gene expression is restored, suggesting that the mechanism of RTS1 rescue includes restoration of specific cell cycle transcripts. Pointing to new mechanisms of acetylation-phosphorylation cross-talk, RTS1 high-copy rescue of gcn5∆ growth requires two residues of H2B that are phosphorylated in human cells. These data highlight the potential significance of dynamic phosphorylation and dephosphorylation of these deeply conserved histone residues for cell viability. PMID:27317677

  16. Interplay among Gcn5, Sch9 and Mitochondria during Chronological Aging of Wine Yeast Is Dependent on Growth Conditions

    PubMed Central

    Picazo, Cecilia; Orozco, Helena; Matallana, Emilia; Aranda, Agustín

    2015-01-01

    Saccharomyces cerevisiae chronological life span (CLS) is determined by a wide variety of environmental and genetic factors. Nutrient limitation without malnutrition, i.e. dietary restriction, expands CLS through the control of nutrient signaling pathways, of which TOR/Sch9 has proven to be the most relevant, particularly under nitrogen deprivation. The use of prototrophic wine yeast allows a better understanding of the role of nitrogen in longevity in natural and more demanding environments, such as grape juice fermentation. We previously showed that acetyltransferase Gcn5, a member of the SAGA complex, has opposite effects on CLS under laboratory and winemaking conditions, and is detrimental under the latter. Here we demonstrate that integrity of the SAGA complex is necessary for prolonged longevity, as its dismantling by SPT20 deletion causes a drop in CLS under both laboratory and winemaking conditions. The sch9Δ mutant is long-lived in synthetic SC medium, as expected, and the combined deletion of GCN5 partially suppresses this phenotype. However it is short-lived in grape juice, likely due to its low nitrogen/carbon ratio. Therefore, unbalance of nutrients can be more relevant for life span than total amounts of them. Deletion of RTG2, which codes for a protein associated with Gcn5 and is a component of the mitochondrial retrograde signal, and which communicates mitochondrial dysfunction to the nucleus, is detrimental under laboratory, but not under winemaking conditions, where respiration seems not so relevant for longevity. Transcription factor Rgm1 was found to be a novel CLS regulator Sch9-dependently. PMID:25658705

  17. Transcriptomic analysis of the GCN5 gene reveals mechanisms of the epigenetic regulation of virulence and morphogenesis in Ustilago maydis.

    PubMed

    Martínez-Soto, Domingo; González-Prieto, Juan Manuel; Ruiz-Herrera, José

    2015-09-01

    Chromatin in the eukaryotic nucleus is highly organized in the form of nucleosomes where histones wrap DNA. This structure may be altered by some chemical modifications of histones, one of them, acetylation by histone acetyltransferases (HATs) that originates relaxation of the nucleosome structure, providing access to different transcription factors and other effectors. In this way, HATs regulate cellular processes including DNA replication, and gene transcription. Previously, we isolated Ustilago maydis mutants deficient in the GCN5 HAT that are avirulent, and grow constitutively as mycelium. In this work, we proceeded to identify the genes differentially regulated by GCN5, comparing the transcriptomes of the mutant and the wild type using microarrays, to analyse the epigenetic control of virulence and morphogenesis. We identified 1203 genes, 574 positively and 629 negatively regulated in the wild type. We found that genes belonging to different categories involved in pathogenesis were downregulated in the mutant, and that genes involved in mycelial growth were negatively regulated in the wild type, offering a working hypothesis on the epigenetic control of virulence and morphogenesis of U. maydis. Interestingly, several differentially regulated genes appeared in clusters, suggesting a common regulation. Some of these belonged to pathogenesis or secondary metabolism. PMID:26126523

  18. [Expression patterns of GCN5 and HDAC1 in preimplantational mouse embryos and effects of in-vitro cultures on their expressions].

    PubMed

    Zhao, Dong Mei; Xu, Chen Ming; Huang, He Feng; Qian, Yu Li; Jin, Fan

    2005-12-01

    To investigate the expression patterns of histone acetyltransferase (GCN5) and histone deacetylase 1 (HDAC1) in preimplantation mouse embryos and the effects of in-vitro cultures on their expressions, immunocytochemistry was used to detect the expressions of GCN5 and HDAC1 in mouse embryos at the stages of two-cell, four-cell, eight-cell, morula and blastocyst in both in-vivo and invitro groups. In in-vivo group, the obvious expressions of GCN5 were observed in the cytoplasm of all kinds of mouse embryos but blastocysts. Meanwhile, HDAC1 was highly expressed in the nuclei of four and eight-cell embryos and morula but mainly seen in the cytoplasm of two-cell embryos. In blastocysts, the HDAC1 fluorescence was limited to the nuclei of trophoblast cells. In in-vitro group, there were no obvious GCN5 expressions in all kinds of embryos and the expression of HDAC1 was significantly reduced although its expression pattern was similar to that of in-vivo group. Those results showed that in -vitro culture environments could inhibit GCN5 expression and decrease the expression of HDAC1 in mouse preimplantation embryos, which might affect the correct embryonic gene expression. PMID:16416968

  19. A unique GCN5-related glucosamine N-acetyltransferase region exist in the fungal multi-domain glycoside hydrolase family 3 β-N-acetylglucosaminidase

    PubMed Central

    Qin, Zhen; Xiao, Yibei; Yang, Xinbin; Mesters, Jeroen R.; Yang, Shaoqing; Jiang, Zhengqiang

    2015-01-01

    Glycoside hydrolase (GH) family 3 β-N-acetylglucosaminidases widely exist in the filamentous fungi, which may play a key role in chitin metabolism of fungi. A multi-domain GH family 3 β-N-acetylglucosaminidase from Rhizomucor miehei (RmNag), exhibiting a potential N-acetyltransferase region, has been recently reported to show great potential in industrial applications. In this study, the crystal structure of RmNag was determined at 2.80 Å resolution. The three-dimensional structure of RmNag showed four distinctive domains, which belong to two distinguishable functional regions — a GH family 3 β-N-acetylglucosaminidase region (N-terminal) and a N-acetyltransferase region (C-terminal). From structural and functional analysis, the C-terminal region of RmNag was identified as a unique tandem array linking general control non-derepressible 5 (GCN5)-related N-acetyltransferase (GNAT), which displayed glucosamine N-acetyltransferase activity. Structural analysis of this glucosamine N-acetyltransferase region revealed that a unique glucosamine binding pocket is located in the pantetheine arm binding terminal region of the conserved CoA binding pocket, which is different from all known GNAT members. This is the first structural report of a glucosamine N-acetyltransferase, which provides novel structural information about substrate specificity of GNATs. The structural and functional features of this multi-domain β-N-acetylglucosaminidase could be useful in studying the catalytic mechanism of GH family 3 proteins. PMID:26669854

  20. A unique GCN5-related glucosamine N-acetyltransferase region exist in the fungal multi-domain glycoside hydrolase family 3 β-N-acetylglucosaminidase.

    PubMed

    Qin, Zhen; Xiao, Yibei; Yang, Xinbin; Mesters, Jeroen R; Yang, Shaoqing; Jiang, Zhengqiang

    2015-01-01

    Glycoside hydrolase (GH) family 3 β-N-acetylglucosaminidases widely exist in the filamentous fungi, which may play a key role in chitin metabolism of fungi. A multi-domain GH family 3 β-N-acetylglucosaminidase from Rhizomucor miehei (RmNag), exhibiting a potential N-acetyltransferase region, has been recently reported to show great potential in industrial applications. In this study, the crystal structure of RmNag was determined at 2.80 Å resolution. The three-dimensional structure of RmNag showed four distinctive domains, which belong to two distinguishable functional regions--a GH family 3 β-N-acetylglucosaminidase region (N-terminal) and a N-acetyltransferase region (C-terminal). From structural and functional analysis, the C-terminal region of RmNag was identified as a unique tandem array linking general control non-derepressible 5 (GCN5)-related N-acetyltransferase (GNAT), which displayed glucosamine N-acetyltransferase activity. Structural analysis of this glucosamine N-acetyltransferase region revealed that a unique glucosamine binding pocket is located in the pantetheine arm binding terminal region of the conserved CoA binding pocket, which is different from all known GNAT members. This is the first structural report of a glucosamine N-acetyltransferase, which provides novel structural information about substrate specificity of GNATs. The structural and functional features of this multi-domain β-N-acetylglucosaminidase could be useful in studying the catalytic mechanism of GH family 3 proteins. PMID:26669854

  1. The SAGA coactivator complex acts on the whole transcribed genome and is required for RNA polymerase II transcription

    PubMed Central

    Bonnet, Jacques; Wang, Chen-Yi; Baptista, Tiago; Vincent, Stéphane D.; Hsiao, Wei-Chun; Stierle, Matthieu; Kao, Cheng-Fu; Tora, László

    2014-01-01

    The SAGA (Spt–Ada–Gcn5 acetyltransferase) coactivator complex contains distinct chromatin-modifying activities and is recruited by DNA-bound activators to regulate the expression of a subset of genes. Surprisingly, recent studies revealed little overlap between genome-wide SAGA-binding profiles and changes in gene expression upon depletion of subunits of the complex. As indicators of SAGA recruitment on chromatin, we monitored in yeast and human cells the genome-wide distribution of histone H3K9 acetylation and H2B ubiquitination, which are respectively deposited or removed by SAGA. Changes in these modifications after inactivation of the corresponding enzyme revealed that SAGA acetylates the promoters and deubiquitinates the transcribed region of all expressed genes. In agreement with this broad distribution, we show that SAGA plays a critical role for RNA polymerase II recruitment at all expressed genes. In addition, through quantification of newly synthesized RNA, we demonstrated that SAGA inactivation induced a strong decrease of mRNA synthesis at all tested genes. Analysis of the SAGA deubiquitination activity further revealed that SAGA acts on the whole transcribed genome in a very fast manner, indicating a highly dynamic association of the complex with chromatin. Thus, our study uncovers a new function for SAGA as a bone fide cofactor for all RNA polymerase II transcription. PMID:25228644

  2. The UmGcn5 gene encoding histone acetyltransferase from Ustilago maydis is involved in dimorphism and virulence.

    PubMed

    González-Prieto, Juan Manuel; Rosas-Quijano, Raymundo; Domínguez, Angel; Ruiz-Herrera, José

    2014-10-01

    We isolated a gene encoding a histone acetyltransferase from Ustilago maydis (DC.) Cda., which is orthologous to the Saccharomyces cerevisiae GCN5 gene. The gene was isolated from genomic clones identified by their specific hybridization to a gene fragment obtained by the polymerase chain reaction (PCR). This gene (Umgcn5; um05168) contains an open reading frame (ORF) of 1421bp that encodes a putative protein of 473 amino acids with a Mr. of 52.6kDa. The protein exhibits a high degree of homology with histone acetyltransferases from different organisms. Null a2b2 ΔUmgcn5 mutants were constructed by substitution of the region encoding the catalytic site with a hygromycin B resistance cassette. Null a1b1 ΔUmgcn5 mutants were isolated from genetic crosses of a2b2 ΔUmgcn5 and a1b1 wild-type strains in maize. Mutants displayed a slight reduction in growth rate under different conditions, and were more sensitive than the wild type to stress conditions, but more important, they grew as long mycelial cells, and formed fuzz-like colonies under all conditions where wild-type strains grew in the yeast-like morphology and formed smooth colonies. This phenotype was not reverted by cAMP addition. Mutants were not virulent to maize plants, and were unable to form teliospores. These phenotypic alterations of the mutants were reverted by their transformation with the wild-type gene. PMID:25242418

  3. In Salmonella enterica, the Gcn5-Related Acetyltransferase MddA (Formerly YncA) Acetylates Methionine Sulfoximine and Methionine Sulfone, Blocking Their Toxic Effects

    PubMed Central

    Hentchel, Kristy L.

    2014-01-01

    Protein and small-molecule acylation reactions are widespread in nature. Many of the enzymes catalyzing acylation reactions belong to the Gcn5-related N-acetyltransferase (GNAT; PF00583) family, named after the yeast Gcn5 protein. The genome of Salmonella enterica serovar Typhimurium LT2 encodes 26 GNATs, 11 of which have no known physiological role. Here, we provide in vivo and in vitro evidence for the role of the MddA (methionine derivative detoxifier; formerly YncA) GNAT in the detoxification of oxidized forms of methionine, including methionine sulfoximine (MSX) and methionine sulfone (MSO). MSX and MSO inhibited the growth of an S. enterica ΔmddA strain unless glutamine or methionine was present in the medium. We used an in vitro spectrophotometric assay and mass spectrometry to show that MddA acetylated MSX and MSO. An mddA+ strain displayed biphasic growth kinetics in the presence of MSX and glutamine. Deletion of two amino acid transporters (GlnHPQ and MetNIQ) in a ΔmddA strain restored growth in the presence of MSX. Notably, MSO was transported by GlnHPQ but not by MetNIQ. In summary, MddA is the mechanism used by S. enterica to respond to oxidized forms of methionine, which MddA detoxifies by acetyl coenzyme A-dependent acetylation. PMID:25368301

  4. In Salmonella enterica, the Gcn5-related acetyltransferase MddA (formerly YncA) acetylates methionine sulfoximine and methionine sulfone, blocking their toxic effects.

    PubMed

    Hentchel, Kristy L; Escalante-Semerena, Jorge C

    2015-01-01

    Protein and small-molecule acylation reactions are widespread in nature. Many of the enzymes catalyzing acylation reactions belong to the Gcn5-related N-acetyltransferase (GNAT; PF00583) family, named after the yeast Gcn5 protein. The genome of Salmonella enterica serovar Typhimurium LT2 encodes 26 GNATs, 11 of which have no known physiological role. Here, we provide in vivo and in vitro evidence for the role of the MddA (methionine derivative detoxifier; formerly YncA) GNAT in the detoxification of oxidized forms of methionine, including methionine sulfoximine (MSX) and methionine sulfone (MSO). MSX and MSO inhibited the growth of an S. enterica ΔmddA strain unless glutamine or methionine was present in the medium. We used an in vitro spectrophotometric assay and mass spectrometry to show that MddA acetylated MSX and MSO. An mddA(+) strain displayed biphasic growth kinetics in the presence of MSX and glutamine. Deletion of two amino acid transporters (GlnHPQ and MetNIQ) in a ΔmddA strain restored growth in the presence of MSX. Notably, MSO was transported by GlnHPQ but not by MetNIQ. In summary, MddA is the mechanism used by S. enterica to respond to oxidized forms of methionine, which MddA detoxifies by acetyl coenzyme A-dependent acetylation. PMID:25368301

  5. Muscle Wasting in Fasting Requires Activation of NF-κB and Inhibition of AKT/Mechanistic Target of Rapamycin (mTOR) by the Protein Acetylase, GCN5.

    PubMed

    Lee, Donghoon; Goldberg, Alfred L

    2015-12-18

    NF-κB is best known for its pro-inflammatory and anti-apoptotic actions, but in skeletal muscle, NF-κB activation is important for atrophy upon denervation or cancer. Here, we show that also upon fasting, NF-κB becomes activated in muscle and is critical for the subsequent atrophy. Following food deprivation, the expression and acetylation of the p65 of NF-κB on lysine 310 increase markedly in muscles. NF-κB inhibition in mouse muscles by overexpression of the IκBα superrepressor (IκBα-SR) or of p65 mutated at Lys-310 prevented atrophy. Knockdown of GCN5 with shRNA or a dominant-negative GCN5 or overexpression of SIRT1 decreased p65K310 acetylation and muscle wasting upon starvation. In addition to reducing atrogene expression, surprisingly inhibiting NF-κB with IκBα-SR or by GCN5 knockdown in these muscles also enhanced AKT and mechanistic target of rapamycin (mTOR) activities, which also contributed to the reduction in atrophy. These new roles of NF-κB and GCN5 in regulating muscle proteolysis and AKT/mTOR signaling suggest novel approaches to combat muscle wasting. PMID:26515065

  6. Play.

    ERIC Educational Resources Information Center

    Rogers, Fred; Sharapan, Hedda

    1993-01-01

    Contends that, in childhood, work and play seem to come together. Says that for young children their play is their work, and the more adults encourage children to play, the more they emphasize important lifelong resource. Examines some uses of children's play, making and building, artwork, dramatic play, monsters and superheroes, gun play, and…

  7. Play

    NASA Astrophysics Data System (ADS)

    Harteveld, Casper

    Designing a game with a serious purpose involves considering the worlds of Reality and Meaning yet it is undeniably impossible to create a game without a third world, one that is specifically concerned with what makes a game a game: the play elements. This third world, the world of people like designers and artists, and disciplines as computer science and game design, I call the world of Play and this level is devoted to it. The level starts off with some of the misperceptions people have of play. Unlike some may think, we play all the time, even when we grow old—this was also very noticeable in designing the game Levee Patroller as the team exhibited very playful behavior at many occasions. From there, I go into the aspects that characterize this world. The first concerns the goal of the game. This relates to the objectives people have to achieve within the game. This is constituted by the second aspect: the gameplay. Taking actions and facing challenges is subsequently constituted by a gameworld, which concerns the third aspect. And all of it is not possible without the fourth and final aspect, the type of technology that creates and facilitates the game. The four aspects together make up a “game concept” and from this world such a concept can be judged on the basis of three closely interrelated criteria: engagement, immersion, and fun.

  8. The Structural Basis of Protein Acetylation by the p300/CBP Transcriptional Coactivator

    SciTech Connect

    Liu,X.; Wang, L.; Zhao, K.; Thompson, P.; Hwang, Y.; Marmorstein, R.; Cole, P.

    2008-01-01

    The transcriptional coactivator p300/CBP (CREBBP) is a histone acetyltransferase (HAT) that regulates gene expression by acetylating histones and other transcription factors. Dysregulation of p300/CBP HAT activity contributes to various diseases including cancer. Sequence alignments, enzymology experiments and inhibitor studies on p300/CBP have led to contradictory results about its catalytic mechanism and its structural relation to the Gcn5/PCAF and MYST HATs. Here we describe a high-resolution X-ray crystal structure of a semi-synthetic heterodimeric p300 HAT domain in complex with a bi-substrate inhibitor, Lys-CoA. This structure shows that p300/CBP is a distant cousin of other structurally characterized HATs, but reveals several novel features that explain the broad substrate specificity and preference for nearby basic residues. Based on this structure and accompanying biochemical data, we propose that p300/CBP uses an unusual 'hit-and-run' (Theorell-Chance) catalytic mechanism that is distinct from other characterized HATs. Several disease-associated mutations can also be readily accounted for by the p300 HAT structure. These studies pave the way for new epigenetic therapies involving modulation of p300/CBP HAT activity.

  9. Sirtuin 1 (SIRT1) Deacetylase Activity Is Not Required for Mitochondrial Biogenesis or Peroxisome Proliferator-activated Receptor-γ Coactivator-1α (PGC-1α) Deacetylation following Endurance Exercise*

    PubMed Central

    Philp, Andrew; Chen, Ai; Lan, Debin; Meyer, Gretchen A.; Murphy, Anne N.; Knapp, Amy E.; Olfert, I. Mark; McCurdy, Carrie E.; Marcotte, George R.; Hogan, Michael C.; Baar, Keith; Schenk, Simon

    2011-01-01

    The protein deacetylase, sirtuin 1 (SIRT1), is a proposed master regulator of exercise-induced mitochondrial biogenesis in skeletal muscle, primarily via its ability to deacetylate and activate peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α). To investigate regulation of mitochondrial biogenesis by SIRT1 in vivo, we generated mice lacking SIRT1 deacetylase activity in skeletal muscle (mKO). We hypothesized that deacetylation of PGC-1α and mitochondrial biogenesis in sedentary mice and after endurance exercise would be impaired in mKO mice. Skeletal muscle contractile characteristics were determined in extensor digitorum longus muscle ex vivo. Mitochondrial biogenesis was assessed after 20 days of voluntary wheel running by measuring electron transport chain protein content, enzyme activity, and mitochondrial DNA expression. PGC-1α expression, nuclear localization, acetylation, and interacting protein association were determined following an acute bout of treadmill exercise (AEX) using co-immunoprecipitation and immunoblotting. Contrary to our hypothesis, skeletal muscle endurance, electron transport chain activity, and voluntary wheel running-induced mitochondrial biogenesis were not impaired in mKO versus wild-type (WT) mice. Moreover, PGC-1α expression, nuclear translocation, activity, and deacetylation after AEX were similar in mKO versus WT mice. Alternatively, we made the novel observation that deacetylation of PGC-1α after AEX occurs in parallel with reduced nuclear abundance of the acetyltransferase, general control of amino-acid synthesis 5 (GCN5), as well as reduced association between GCN5 and nuclear PGC-1α. These findings demonstrate that SIRT1 deacetylase activity is not required for exercise-induced deacetylation of PGC-1α or mitochondrial biogenesis in skeletal muscle and suggest that changes in GCN5 acetyltransferase activity may be an important regulator of PGC-1α activity after exercise. PMID:21757760

  10. Aggregation of Polyglutamine-expanded Ataxin 7 Protein Specifically Sequesters Ubiquitin-specific Protease 22 and Deteriorates Its Deubiquitinating Function in the Spt-Ada-Gcn5-Acetyltransferase (SAGA) Complex.

    PubMed

    Yang, Hui; Liu, Shuai; He, Wen-Tian; Zhao, Jian; Jiang, Lei-Lei; Hu, Hong-Yu

    2015-09-01

    Human ataxin 7 (Atx7) is a component of the deubiquitination module (DUBm) in the Spt-Ada-Gcn5-acetyltransferase (SAGA) complex for transcriptional regulation, and expansion of its polyglutamine (polyQ) tract leads to spinocerebellar ataxia type 7. However, how polyQ expansion of Atx7 affects DUBm function remains elusive. We investigated the effects of polyQ-expanded Atx7 on ubiquitin-specific protease (USP22), an interacting partner of Atx7 functioning in deubiquitination of histone H2B. The results showed that the inclusions or aggregates formed by polyQ-expanded Atx7 specifically sequester USP22 through their interactions mediated by the N-terminal zinc finger domain of Atx7. The mutation of the zinc finger domain in Atx7 that disrupts its interaction with USP22 dramatically abolishes sequestration of USP22. Moreover, polyQ expansion of Atx7 decreases the deubiquitinating activity of USP22 and, consequently, increases the level of monoubiquitinated H2B. Therefore, we propose that polyQ-expanded Atx7 forms insoluble aggregates that sequester USP22 into a catalytically inactive state, and then the impaired DUBm loses the function to deubiquitinate monoubiquitinated histone H2B or H2A. This may result in dysfunction of the SAGA complex and transcriptional dysregulation in spinocerebellar ataxia type 7 disease. PMID:26195632

  11. The crystal structure of Rv1347c, a putative antibiotic resistance protein from Mycobacterium tuberculosis, reveals a GCN5-related fold and suggests an alternative function in siderophore biosynthesis

    SciTech Connect

    Card, G L; Peterson, N A; Smith, C A; Rupp, B; Schick, B M; Baker, E N

    2005-02-15

    Mycobacterium tuberculosis, the cause of TB, is a devastating human pathogen. The emergence of multi-drug resistance in recent years has prompted a search for new drug targets and for a better understanding of mechanisms of resistance. Here we focus on the gene product of an open reading frame from M. tuberculosis, Rv1347c, which is annotated as a putative aminoglycoside N-acetyltransferase. The Rv1347c protein does not show this activity, however, and we show from its crystal structure, coupled with functional and bioinformatic data, that its most likely role is in the biosynthesis of mycobactin, the M. tuberculosis siderophore. The crystal structure of Rv1347c was determined by MAD phasing from selenomethionine-substituted protein and refined at 2.2 {angstrom} resolution (R = 0.227, R{sub free} = 0.257). The protein is monomeric, with a fold that places it in the GCN5-related N-acetyltransferase (GNAT) family of acyltransferases. Features of the structure are an acylCoA binding site that is shared with other GNAT family members, and an adjacent hydrophobic channel leading to the surface that could accommodate long-chain acyl groups. Modeling the postulated substrate, the N{sup {var_epsilon}}-hydroxylysine side chain of mycobactin, into the acceptor substrate binding groove identifies two residues at the active site, His130 and Asp168, that have putative roles in substrate binding and catalysis.

  12. The Histone Acetylase PCAF Is a Phorbol-Ester-Inducible Coactivator of the IRF Family That Confers Enhanced Interferon Responsiveness

    PubMed Central

    Masumi, Atsuko; Wang, I-Ming; Lefebvre, Bruno; Yang, Xing-Jiao; Nakatani, Yoshihiro; Ozato, Keiko

    1999-01-01

    Transcription factors of the interferon regulatory factor (IRF) family bind to the type I interferon (IFN)-responsive element (ISRE) and activate transcription from IFN-inducible genes. To identify cofactors that associate with IRF proteins, DNA affinity binding assays were performed with nuclear extracts prepared from tissue culture cells. The results demonstrated that the endogenous IRFs bound to the ISRE are complexed with the histone acetylases, PCAF, GCN5, and p300/CREB binding protein and that histone acetylase activities are accumulated on the IRF-ISRE complexes. By testing recombinant proteins, we show that PCAF directly binds to some but not all members of the IRF family through distinct domains of the two proteins. This interaction was functionally significant, since transfection of PCAF strongly enhanced IRF-1- and IRF-2-dependent promoter activities. Further studies showed that expression of PCAF and other histone acetylases was markedly induced in U937 cells upon phorbol ester treatment, which led to increased recruitment of PCAF to the IRF-ISRE complexes. Coinciding with the induction of histone acetylases, phorbol ester markedly enhanced IFN-α-stimulated gene expression in U937 cells. Supporting the role for PCAF in conferring IFN responsiveness, transfection of PCAF into U937 cells led to a large increase in IFN-α-inducible promoter activity. These results demonstrate that PCAF is a phorbol ester-inducible coactivator of the IRF proteins which contributes to the establishment of type I IFN responsiveness. PMID:10022868

  13. Tudor Staphylococcal Nuclease (Tudor-SN), a Novel Regulator Facilitating G1/S Phase Transition, Acting as a Co-activator of E2F-1 in Cell Cycle Regulation*

    PubMed Central

    Su, Chao; Zhang, Chunyan; Tecle, Adiam; Fu, Xue; He, Jinyan; Song, Juan; Zhang, Wei; Sun, Xiaoming; Ren, Yuanyuan; Silvennoinen, Olli; Yao, Zhi; Yang, Xi; Wei, Minxin; Yang, Jie

    2015-01-01

    Tudor staphylococcal nuclease (Tudor-SN) is a multifunctional protein implicated in a variety of cellular processes. In the present study, we identified Tudor-SN as a novel regulator in cell cycle. Tudor-SN was abundant in proliferating cells whereas barely expressed in terminally differentiated cells. Functional analysis indicated that ectopic overexpression of Tudor-SN promoted the G1/S transition, whereas knockdown of Tudor-SN caused G1 arrest. Moreover, the live-cell time-lapse experiment demonstrated that the cell cycle of MEF−/− (knock-out of Tudor-SN in mouse embryonic fibroblasts) was prolonged compared with wild-type MEF+/+. We noticed that Tudor-SN was constantly expressed in every cell cycle phase, but was highly phosphorylated in the G1/S border. Further study revealed that Tudor-SN was a potential substrate of Cdk2/4/6, supportively, we found the physical interaction of endogenous Tudor-SN with Cdk4/6 in G1 and the G1/S border, and with Cdk2 in the G1/S border and S phase. In addition, roscovitine (Cdk1/2/5 inhibitor) or CINK4 (Cdk4/6 inhibitor) could inhibit the phosphorylation of Tudor-SN, whereas ectopic overexpression of Cdk2/4/6 increased the Tudor-SN phosphorylation. The underlying molecular mechanisms indicated that Tudor-SN could physically interact with E2F-1 in vivo, and could enhance the physical association of E2F-1 with GCN5 (a cofactor of E2F-1, which possesses histone acetyltransferase activity), and promote the binding ability of E2F-1 to the promoter region of its target genes CYCLIN A and E2F-1, and as a result, facilitate the gene transcriptional activation. Taken together, Tudor-SN is identified as a novel co-activator of E2F-1, which could facilitate E2F-1-mediated gene transcriptional activation of target genes, which play essential roles in G1/S transition. PMID:25627688

  14. Selective recognition of acetylated histones by bromodomains in transcriptional co-activators

    PubMed Central

    Hassan, Ahmed H.; Awad, Salma; Al-Natour, Zeina; Othman, Samah; Mustafa, Farah; Rizvi, Tahir A.

    2006-01-01

    Bromodomains are present in many chromatin-associated proteins such as the SWI/SNF and RSC chromatin remodelling and the SAGA HAT (histone acetyltransferase) complexes, and can bind to acetylated lysine residues in the N-terminal tails of the histones. Lysine acetylation is a histone modification that forms a stable epigenetic mark on chromatin for bromodomain-containing proteins to dock and in turn regulate gene expression. In order to better understand how bromodomains read the ‘histone code’ and interact with acetylated histones, we have tested the interactions of several bromodomains within transcriptional co-activators with differentially acetylated histone tail peptides and HAT-acetylated histones. Using GST (glutathione S-transferase) pull-down assays, we show specificity of binding of some bromodomains to differentially acetylated H3 and H4 peptides as well as HAT-acetylated histones. Our results reveal that the Swi2/Snf2 bromodomain interacts with various acetylated H3 and H4 peptides, whereas the Gcn5 bromodomain interacts only with acetylated H3 peptides and tetra-acetylated H4 peptides. Additionally we show that the Spt7 bromodomain interacts with acetylated H3 peptides weakly, but not with acetylated H4 peptides. Some bromodomains such as the Bdf1-2 do not interact with most of the acetylated peptides tested. Results of the peptide experiments are confirmed with tests of interactions between these bromodomains and HAT-acetylated histones. Furthermore, we demonstrate that the Swi2/Snf2 bromodomain is important for the binding and the remodelling activity of the SWI/SNF complex on hyperacetylated nucleosomes. The selective recognition of the bromodomains observed in the present study accounts for the broad effects of bromodomain-containing proteins observed on binding to histones. PMID:17049045

  15. Coactivators in PPAR-Regulated Gene Expression

    PubMed Central

    Viswakarma, Navin; Jia, Yuzhi; Bai, Liang; Vluggens, Aurore; Borensztajn, Jayme; Xu, Jianming; Reddy, Janardan K.

    2010-01-01

    Peroxisome proliferator-activated receptor (PPAR)α, β (also known as δ), and γ function as sensors for fatty acids and fatty acid derivatives and control important metabolic pathways involved in the maintenance of energy balance. PPARs also regulate other diverse biological processes such as development, differentiation, inflammation, and neoplasia. In the nucleus, PPARs exist as heterodimers with retinoid X receptor-α bound to DNA with corepressor molecules. Upon ligand activation, PPARs undergo conformational changes that facilitate the dissociation of corepressor molecules and invoke a spatiotemporally orchestrated recruitment of transcription cofactors including coactivators and coactivator-associated proteins. While a given nuclear receptor regulates the expression of a prescribed set of target genes, coactivators are likely to influence the functioning of many regulators and thus affect the transcription of many genes. Evidence suggests that some of the coactivators such as PPAR-binding protein (PBP/PPARBP), thyroid hormone receptor-associated protein 220 (TRAP220), and mediator complex subunit 1 (MED1) may exert a broader influence on the functions of several nuclear receptors and their target genes. Investigations into the role of coactivators in the function of PPARs should strengthen our understanding of the complexities of metabolic diseases associated with energy metabolism. PMID:20814439

  16. Bimodal Bilinguals Co-activate Both Languages during Spoken Comprehension

    PubMed Central

    Shook, Anthony; Marian, Viorica

    2012-01-01

    Bilinguals have been shown to activate their two languages in parallel, and this process can often be attributed to overlap in input between the two languages. The present study examines whether two languages that do not overlap in input structure, and that have distinct phonological systems, such as American Sign Language (ASL) and English, are also activated in parallel. Hearing ASL-English bimodal bilinguals’ and English monolinguals’ eye-movements were recorded during a visual world paradigm, in which participants were instructed, in English, to select objects from a display. In critical trials, the target item appeared with a competing item that overlapped with the target in ASL phonology. Bimodal bilinguals looked more at competing items than at phonologically unrelated items, and looked more at competing items relative to monolinguals, indicating activation of the sign-language during spoken English comprehension. The findings suggest that language co-activation is not modality specific, and provide insight into the mechanisms that may underlie cross-modal language co-activation in bimodal bilinguals, including the role that top-down and lateral connections between levels of processing may play in language comprehension. PMID:22770677

  17. Molecular cloning and properties of a full-length putative thyroid hormone receptor coactivator.

    PubMed

    Takeshita, A; Yen, P M; Misiti, S; Cardona, G R; Liu, Y; Chin, W W

    1996-08-01

    Thyroid hormone receptors (TRs) are ligand-dependent transcription factors that regulate target gene transcription. The conserved carboxy-terminal region of the ligand-binding domain (AF-2) has been thought to play a critical role in mediating ligand-dependent transactivation by the interaction with coactivator(s). Using bacterially-expressed TR as a probe, far-Western-based expression cDNA library screening identified cDNAs that encode, in part, the recently reported partial steroid receptor coactivator-1 (SRC-1) sequence. Additional work, including 5' RACE, has characterized a full-length cDNA that encodes a approximately 160 kD protein as a putative thyroid hormone receptor coactivator (F-SRC-1). In vitro binding studies show that F-SRC-1 binds to a variety of nuclear hormone receptors in a ligand-dependent manner, along with TBP and TFIIB, suggesting that F-SRC-1 may play a role as a bridging molecule between nuclear hormone receptors and general transcription factors. Interestingly, AF-2 mutants also retain ligand-dependent interaction with F-SRC-1. Although F-SRC-1 recognizes the ligand-induced conformational changes of nuclear hormone receptors, our observations suggest that F-SRC-1 may bind directly with subregion(s) in nuclear hormone receptors other than the AF-2 region. PMID:8754792

  18. Networks of Task Co-Activations

    PubMed Central

    Laird, Angela R.; Eickhoff, Simon B.; Rottschy, Claudia; Bzdok, Danilo; Ray, Kimberly L.; Fox, Peter T.

    2013-01-01

    Recent progress in neuroimaging informatics and meta-analytic techniques has enabled a novel domain of human brain connectomics research that focuses on task-dependent co-activation patterns across behavioral tasks and cognitive domains. Here, we review studies utilizing the BrainMap database to investigate data trends in the activation literature using methods such as meta-analytic connectivity modeling (MACM), connectivity-based parcellation (CPB), and independent component analysis (ICA). We give examples of how these methods are being applied to learn more about the functional connectivity of areas such as the amygdala, the default mode network, and visual area V5. Methods for analyzing the behavioral metadata corresponding to regions of interest and to their intrinsically connected networks are described as a tool for local functional decoding. We finally discuss the relation of observed co-activation connectivity results to resting state connectivity patterns, and provide implications for future work in this domain. PMID:23631994

  19. Coactivator cross-talk specifies transcriptional output

    PubMed Central

    Marr, Michael T.; Isogai, Yoh; Wright, Kevin J.; Tjian, Robert

    2006-01-01

    Cells often fine-tune gene expression at the level of transcription to generate the appropriate response to a given environmental or developmental stimulus. Both positive and negative influences on gene expression must be balanced to produce the correct level of mRNA synthesis. To this end, the cell uses several classes of regulatory coactivator complexes including two central players, TFIID and Mediator (MED), in potentiating activated transcription. Both of these complexes integrate activator signals and convey them to the basal apparatus. Interestingly, many promoters require both regulatory complexes, although at first glance they may seem to be redundant. Here we have used RNA interference (RNAi) in Drosophila cells to selectively deplete subunits of the MED and TFIID complexes to dissect the contribution of each of these complexes in modulating activated transcription. We exploited the robust response of the metallothionein genes to heavy metal as a model for transcriptional activation by analyzing direct factor recruitment in both heterogeneous cell populations and at the single-cell level. Intriguingly, we find that MED and TFIID interact functionally to modulate transcriptional response to metal. The metal response element-binding transcription factor-1 (MTF-1) recruits TFIID, which then binds promoter DNA, setting up a “checkpoint complex” for the initiation of transcription that is subsequently activated upon recruitment of the MED complex. The appropriate expression level of the endogenous metallothionein genes is achieved only when the activities of these two coactivators are balanced. Surprisingly, we find that the same activator (MTF-1) requires different coactivator subunits depending on the context of the core promoter. Finally, we find that the stability of multi-subunit coactivator complexes can be compromised by loss of a single subunit, underscoring the potential for combinatorial control of transcription activation. PMID:16751183

  20. Protein arginine methyltransferase 5 (PRMT5) is a novel coactivator of constitutive androstane receptor (CAR).

    PubMed

    Kanno, Yuichiro; Inajima, Jun; Kato, Sayaka; Matsumoto, Maika; Tokumoto, Chikako; Kure, Yuki; Inouye, Yoshio

    2015-03-27

    The constitutive androstane receptor (CAR) plays a key role in the expression of xenobiotic/steroid and drug metabolizing enzymes and their transporters. In this study, we demonstrated that protein arginine methyltransferase 5 (PRMT5) is a novel CAR-interacting protein. Furthermore, the PRMT-dependent induction of a CAR reporter gene, which was independent of methyltransferase activity, was enhanced in the presence of steroid receptor coactivator 1 (SRC1), peroxisome proliferator-activated receptor-gamma coactivator 1 alpha (PGC-1α) or DEAD box DNA/RNA helicase DP97. Using tetracycline inducible-hCAR system in HepG2 cells, we showed that knockdown of PRMT5 with small interfering RNA suppressed tetracycline -induced mRNA expression of CYP2B6 but not of CYP2C9 or CYP3A4. PRMT5 enhanced phenobarbital-mediated transactivation of a phenobarbital-responsive enhancer module (PBREM)-driven reporter gene in co-operation with PGC-1α in rat primary hepatocytes. Based on these findings, we suggest PRMT5 to be a gene (or promoter)-selective coactivator of CAR by mediating the formation of complexes between hCAR and appropriate coactivators. PMID:25721668

  1. Protein arginine methyltransferase 5 (PRMT5) is a novel coactivator of constitutive androstane receptor (CAR)

    SciTech Connect

    Kanno, Yuichiro Inajima, Jun; Kato, Sayaka; Matsumoto, Maika; Tokumoto, Chikako; Kure, Yuki; Inouye, Yoshio

    2015-03-27

    The constitutive androstane receptor (CAR) plays a key role in the expression of xenobiotic/steroid and drug metabolizing enzymes and their transporters. In this study, we demonstrated that protein arginine methyltransferase 5 (PRMT5) is a novel CAR-interacting protein. Furthermore, the PRMT-dependent induction of a CAR reporter gene, which was independent of methyltransferase activity, was enhanced in the presence of steroid receptor coactivator 1 (SRC1), peroxisome proliferator-activated receptor-gamma coactivator 1 alpha (PGC-1α) or DEAD box DNA/RNA helicase DP97. Using tetracycline inducible-hCAR system in HepG2 cells, we showed that knockdown of PRMT5 with small interfering RNA suppressed tetracycline -induced mRNA expression of CYP2B6 but not of CYP2C9 or CYP3A4. PRMT5 enhanced phenobarbital-mediated transactivation of a phenobarbital-responsive enhancer module (PBREM)-driven reporter gene in co-operation with PGC-1α in rat primary hepatocytes. Based on these findings, we suggest PRMT5 to be a gene (or promoter)-selective coactivator of CAR by mediating the formation of complexes between hCAR and appropriate coactivators. - Highlights: • Nuclear receptor CAR interact with PRMT5. • PRMT5 enhances transcriptional activity of CAR. • PRMT5 synergistically enhances transactivity of CAR by the co-expression of SRC-1, DP97 or PGC1α. • PRMT5 is a gene-selective co-activator for hCAR.

  2. Recognition and Accommodation at the Androgen Receptor Coactivator Binding Interface

    PubMed Central

    Hur, Eugene; Pfaff, Samuel J; Payne, E. Sturgis; Grøn, Hanne; Buehrer, Benjamin M

    2004-01-01

    Prostate cancer is a leading killer of men in the industrialized world. Underlying this disease is the aberrant action of the androgen receptor (AR). AR is distinguished from other nuclear receptors in that after hormone binding, it preferentially responds to a specialized set of coactivators bearing aromatic-rich motifs, while responding poorly to coactivators bearing the leucine-rich “NR box” motifs favored by other nuclear receptors. Under normal conditions, interactions with these AR-specific coactivators through aromatic-rich motifs underlie targeted gene transcription. However, during prostate cancer, abnormal association with such coactivators, as well as with coactivators containing canonical leucine-rich motifs, promotes disease progression. To understand the paradox of this unusual selectivity, we have derived a complete set of peptide motifs that interact with AR using phage display. Binding affinities were measured for a selected set of these peptides and their interactions with AR determined by X-ray crystallography. Structures of AR in complex with FxxLF, LxxLL, FxxLW, WxxLF, WxxVW, FxxFF, and FxxYF motifs reveal a changing surface of the AR coactivator binding interface that permits accommodation of both AR-specific aromatic-rich motifs and canonical leucine-rich motifs. Induced fit provides perfect mating of the motifs representing the known family of AR coactivators and suggests a framework for the design of AR coactivator antagonists. PMID:15328534

  3. Receptor Coactivators: Master Regulators of Human Health and Disease

    PubMed Central

    Dasgupta, Subhamoy; Lonard, David M.; O’Malley, Bert W.

    2015-01-01

    Transcriptional coregulators (coactivators and corepressors) have emerged as the principal modulators of the functions of nuclear receptors and other transcription factors. During the decade since the discovery of steroid receptor coactivator-1 (SRC-1), the first authentic coregulator, more than 400 coregulators have been identified and characterized, and deciphering their function has contributed significantly to our understanding of their role in human physiology. Deregulated expression of coregulators has been implicated in diverse disease states and related pathologies. The advancement of molecular technologies has enabled us to better characterize the molecular associations of the SRC family of coactivators with other protein complexes in the context of gene regulation. These continuing discoveries not only expand our knowledge of the roles of coactivators in various human diseases but allow us to discover novel coactivator-targeting strategies for therapeutic intervention in these diseases. PMID:24111892

  4. A coactive interdisciplinary research program with NASA

    NASA Technical Reports Server (NTRS)

    Rouse, J. W., Jr.

    1972-01-01

    The applications area of the Texas A&M University remote sensing program consists of a series of coactive projects with NASA/MSC personnel. In each case, the Remote Sensing Center has served to complement and enhance the research capability within the Manned Spacecraft Center. In addition to the applications study area, the Texas A&M University program includes coordinated projects in sensors and data analysis. Under the sensors area, an extensive experimental study of microwave radiometry for soil moisture determination established the effect of soil moisture on the measured brightness temperature for several different soil types. The data analysis area included a project which ERTS-A and Skylab data were simulated using aircraft multispectral scanner measurements at two altitudes. This effort resulted in development of a library of computer programs which provides an operational capability in classification analysis of multispectral data.

  5. PPARγ co-activator-1α co-activates steroidogenic factor 1 to stimulate the synthesis of luteinizing hormone and aldosterone.

    PubMed

    Zhu, Liuluan; Ke, Yaojun; Shao, Di; Cui, Ying; Qiao, Aijun; Liu, Xiaojun; Fang, Fude; Chang, Yongsheng

    2010-12-15

    The orphan nuclear receptor SF-1 (steroidogenic factor 1) is highly expressed in the pituitary, gonad and adrenal glands and plays key roles at all levels of the hypothalamic-pituitary-steroidogenic tissue axis. In the present study, we show that PGC-1α [PPARγ (peroxisome-proliferator-activated receptor γ) co-activator 1α] interacts with and co-activates SF-1 to induce LHβ (luteinizing hormone β) and αGSU (α-glycoprotein subunit) gene expression, subsequently leading to the increased secretion of LH in pituitary gonadotrope-derived αT3-1 cells. PGC-1α co-activation of LHβ expression requires an SF-1-binding element [GSE (gonadotrope-specific element)] mapped to the promoter region of LHβ. Mammalian two-hybrid and co-immunoprecipitation assays, as well as GST (glutathione transferase) pull-down experiments demonstrated that PGC-1α interacts with SF-1 in vivo and in vitro. Additionally, PGC-1α stimulates the expression of Cyp11b2 (aldosterone synthase gene), Cyp11b1 (steroid 11β-hydroxylase gene) and P450scc (cholesterol side-chain cleavage enzyme), and the synthesis of aldosterone in adrenal-cortex-derived Y-1 cells. Chromatin immunoprecipitation assays confirmed that endogenous PGC-1α co-localizes with SF-1 in the LHβ and Cyp11b2 promoter region. Knockdown of endogenous SF-1 by siRNA (small interfering RNA) abolished the PGC-1α induction of LHβ and Cyp11b2 gene expression in αT3-1 and Y-1 cells respectively. Finally, we demonstrated that PGC-1α induces SF-1 gene expression in both αT3-1 and Y-1 cells. Taken together, our findings reveal the potential role of PGC-1α and suggest that it may play important roles in steroidogenesis, gonad development and sex differentiation through SF-1. PMID:21108604

  6. Cryptocephal, the Drosophila melanogaster ATF4, Is a Specific Coactivator for Ecdysone Receptor Isoform B2

    PubMed Central

    Gauthier, Sebastien A.; VanHaaften, Eric; Cherbas, Lucy; Cherbas, Peter; Hewes, Randall S.

    2012-01-01

    The ecdysone receptor is a heterodimer of two nuclear receptors, the Ecdysone receptor (EcR) and Ultraspiracle (USP). In Drosophila melanogaster, three EcR isoforms share common DNA and ligand-binding domains, but these proteins differ in their most N-terminal regions and, consequently, in the activation domains (AF1s) contained therein. The transcriptional coactivators for these domains, which impart unique transcriptional regulatory properties to the EcR isoforms, are unknown. Activating transcription factor 4 (ATF4) is a basic-leucine zipper transcription factor that plays a central role in the stress response of mammals. Here we show that Cryptocephal (CRC), the Drosophila homolog of ATF4, is an ecdysone receptor coactivator that is specific for isoform B2. CRC interacts with EcR-B2 to promote ecdysone-dependent expression of ecdysis-triggering hormone (ETH), an essential regulator of insect molting behavior. We propose that this interaction explains some of the differences in transcriptional properties that are displayed by the EcR isoforms, and similar interactions may underlie the differential activities of other nuclear receptors with distinct AF1-coactivators. PMID:22912598

  7. Antagonist coactivation of trunk stabilizer muscles during Pilates exercises.

    PubMed

    Rossi, Denise Martineli; Morcelli, Mary Hellen; Marques, Nise Ribeiro; Hallal, Camilla Zamfolini; Gonçalves, Mauro; Laroche, Dain P; Navega, Marcelo Tavella

    2014-01-01

    The purpose of this study was to compare the antagonist coactivation of the local and global trunk muscles during mat-based exercises of Skilled Modern Pilates. Twelve women performed five exercises and concurrently, surface EMG from internal oblique (OI), multifidus (MU), rectus abdominis (RA) and iliocostalis lumborum (IL) muscles was recorded bilaterally. The percentage of antagonist coactivation between local (OI/MU) and global muscles (RA/IL) was calculated. Individuals new to the practice of these exercises showed differences in coactivation of the trunk muscles between the exercises and these results were not similar bilaterally. Thus, in clinical practice, the therapist should be aware of factors such as compensation and undesirable rotation movements of the trunk. Moreover, the coactivation of global muscles was higher bilaterally in all exercises analyzed. This suggests that the exercises of Skilled Modern Pilates only should be performed after appropriate learning and correct execution of all principles, mainly the Centering Principle. PMID:24411147

  8. Carbidopa abrogates L-dopa decarboxylase coactivation of the androgen receptor and delays prostate tumor progression.

    PubMed

    Wafa, Latif A; Cheng, Helen; Plaa, Nathan; Ghaidi, Fariba; Fukumoto, Takahiro; Fazli, Ladan; Gleave, Martin E; Cox, Michael E; Rennie, Paul S

    2012-06-15

    The androgen receptor (AR) plays a central role in prostate cancer progression to the castration-resistant (CR) lethal state. L-Dopa decarboxylase (DDC) is an AR coactivator that increases in expression with disease progression and is coexpressed with the receptor in prostate adenocarcinoma cells, where it may enhance AR activity. Here, we hypothesize that the DDC enzymatic inhibitor, carbidopa, can suppress DDC-coactivation of AR and retard prostate tumor growth. Treating LNCaP prostate cancer cells with carbidopa in transcriptional assays suppressed the enhanced AR transactivation seen with DDC overexpression and decreased prostate-specific antigen (PSA) mRNA levels. Carbidopa dose-dependently inhibited cell growth and decreased survival in LNCaP cell proliferation and apoptosis assays. The inhibitory effect of carbidopa on DDC-coactivation of AR and cell growth/survival was also observed in PC3 prostate cancer cells (stably expressing AR). In vivo studies demonstrated that serum PSA velocity and tumor growth rates elevated ∼2-fold in LNCaP xenografts, inducibly overexpressing DDC, were reverted to control levels with carbidopa administration. In castrated mice, treating LNCaP tumors, expressing endogenous DDC, with carbidopa delayed progression to the CR state from 6 to 10 weeks, while serum PSA and tumor growth decreased 4.3-fold and 5.4-fold, respectively. Our study is a first time demonstration that carbidopa can abrogate DDC-coactivation of AR in prostate cancer cells and tumors, decrease serum PSA, reduce tumor growth and delay CR progression. Since carbidopa is clinically approved, it may be readily used as a novel therapeutic strategy to suppress aberrant AR activity and delay prostate cancer progression. PMID:21780103

  9. ERAP140, a conserved tissue-specific nuclear receptor coactivator.

    PubMed

    Shao, Wenlin; Halachmi, Shlomit; Brown, Myles

    2002-05-01

    We report here the identification and characterization of a novel nuclear receptor coactivator, ERAP140. ERAP140 was isolated in a screen for ER alpha-interacting proteins using the ER alpha ligand binding domain as a probe. The ERAP140 protein shares no sequence and has little structural homology with other nuclear receptor cofactors. However, homologues of ERAP140 have been identified in mouse, Drosophila, and Caenorhabditis elegans. The expression of ERAP140 is cell and tissue type specific and is most abundant in the brain, where its expression is restricted to neurons. In addition to interacting with ER alpha, ERAP140 also binds ER beta, TR beta, PPAR gamma, and RAR alpha. ERAP140 interacts with ER alpha via a noncanonical interaction motif. The ER alpha-ERAP140 association can be competed by coactivator NR boxes, indicating ERAP140 binds ER alpha on a surface similar to that of other coactivators. ERAP140 can enhance the transcriptional activities of nuclear receptors with which it interacts. In vivo, ERAP140 is recruited by estrogen-bound ER alpha to the promoter region of endogenous ER alpha target genes. Furthermore, the E(2)-induced recruitment of ERAP140 to the promoter follows a cyclic pattern similar to that of other coactivators. Our results suggest that ERAP140 represents a distinct class of nuclear receptor coactivators that mediates receptor signaling in specific target tissues. PMID:11971969

  10. Molecular Dynamics of "Fuzzy" Transcriptional Activator-Coactivator Interactions.

    PubMed

    Scholes, Natalie S; Weinzierl, Robert O J

    2016-05-01

    Transcriptional activation domains (ADs) are generally thought to be intrinsically unstructured, but capable of adopting limited secondary structure upon interaction with a coactivator surface. The indeterminate nature of this interface made it hitherto difficult to study structure/function relationships of such contacts. Here we used atomistic accelerated molecular dynamics (aMD) simulations to study the conformational changes of the GCN4 AD and variants thereof, either free in solution, or bound to the GAL11 coactivator surface. We show that the AD-coactivator interactions are highly dynamic while obeying distinct rules. The data provide insights into the constant and variable aspects of orientation of ADs relative to the coactivator, changes in secondary structure and energetic contributions stabilizing the various conformers at different time points. We also demonstrate that a prediction of α-helical propensity correlates directly with the experimentally measured transactivation potential of a large set of mutagenized ADs. The link between α-helical propensity and the stimulatory activity of ADs has fundamental practical and theoretical implications concerning the recruitment of ADs to coactivators. PMID:27175900

  11. Molecular Dynamics of "Fuzzy" Transcriptional Activator-Coactivator Interactions

    PubMed Central

    Scholes, Natalie S.; Weinzierl, Robert O. J.

    2016-01-01

    Transcriptional activation domains (ADs) are generally thought to be intrinsically unstructured, but capable of adopting limited secondary structure upon interaction with a coactivator surface. The indeterminate nature of this interface made it hitherto difficult to study structure/function relationships of such contacts. Here we used atomistic accelerated molecular dynamics (aMD) simulations to study the conformational changes of the GCN4 AD and variants thereof, either free in solution, or bound to the GAL11 coactivator surface. We show that the AD-coactivator interactions are highly dynamic while obeying distinct rules. The data provide insights into the constant and variable aspects of orientation of ADs relative to the coactivator, changes in secondary structure and energetic contributions stabilizing the various conformers at different time points. We also demonstrate that a prediction of α-helical propensity correlates directly with the experimentally measured transactivation potential of a large set of mutagenized ADs. The link between α-helical propensity and the stimulatory activity of ADs has fundamental practical and theoretical implications concerning the recruitment of ADs to coactivators. PMID:27175900

  12. PRIC295, a Nuclear Receptor Coactivator, Identified from PPARα-Interacting Cofactor Complex

    PubMed Central

    Pyper, Sean R.; Viswakarma, Navin; Jia, Yuzhi; Zhu, Yi-Jun; Fondell, Joseph D.; Reddy, Janardan K.

    2010-01-01

    The peroxisome proliferator-activated receptor-α (PPARα) plays a key role in lipid metabolism and energy combustion. Chronic activation of PPARα in rodents leads to the development of hepatocellular carcinomas. The ability of PPARα to induce expression of its target genes depends on Mediator, an evolutionarily conserved complex of cofactors and, in particular, the subunit 1 (Med1) of this complex. Here, we report the identification and characterization of PPARα-interacting cofactor (PRIC)-295 (PRIC295), a novel coactivator protein, and show that it interacts with the Med1 and Med24 subunits of the Mediator complex. PRIC295 contains 10 LXXLL signature motifs that facilitate nuclear receptor binding and interacts with PPARα and five other members of the nuclear receptor superfamily in a ligand-dependent manner. PRIC295 enhances the transactivation function of PPARα, PPARγ, and ERα. These data demonstrate that PRIC295 interacts with nuclear receptors such as PPARα and functions as a transcription coactivator under in vitro conditions and may play an important role in mediating the effects in vivo as a member of the PRIC complex with Med1 and Med24. PMID:20885938

  13. Co-activation Probability Estimation (CoPE): An approach for modeling functional co-activation architecture based on neuroimaging coordinates.

    PubMed

    Chu, Congying; Fan, Lingzhong; Eickhoff, Claudia R; Liu, Yong; Yang, Yong; Eickhoff, Simon B; Jiang, Tianzi

    2015-08-15

    Recent progress in functional neuroimaging has prompted studies of brain activation during various cognitive tasks. Coordinate-based meta-analysis has been utilized to discover the brain regions that are consistently activated across experiments. However, within-experiment co-activation relationships, which can reflect the underlying functional relationships between different brain regions, have not been widely studied. In particular, voxel-wise co-activation, which may be able to provide a detailed configuration of the co-activation network, still needs to be modeled. To estimate the voxel-wise co-activation pattern and deduce the co-activation network, a Co-activation Probability Estimation (CoPE) method was proposed to model within-experiment activations for the purpose of defining the co-activations. A permutation test was adopted as a significance test. Moreover, the co-activations were automatically separated into local and long-range ones, based on distance. The two types of co-activations describe distinct features: the first reflects convergent activations; the second represents co-activations between different brain regions. The validation of CoPE was based on five simulation tests and one real dataset derived from studies of working memory. Both the simulated and the real data demonstrated that CoPE was not only able to find local convergence but also significant long-range co-activation. In particular, CoPE was able to identify a 'core' co-activation network in the working memory dataset. As a data-driven method, the CoPE method can be used to mine underlying co-activation relationships across experiments in future studies. PMID:26037052

  14. Dissecting allosteric effects of activator–coactivator complexes using a covalent small molecule ligand

    PubMed Central

    Wang, Ningkun; Lodge, Jean M.; Fierke, Carol A.; Mapp, Anna K.

    2014-01-01

    Allosteric binding events play a critical role in the formation and stability of transcriptional activator–coactivator complexes, perhaps in part due to the often intrinsically disordered nature of one or more of the constituent partners. The kinase-inducible domain interacting (KIX) domain of the master coactivator CREB binding protein/p300 is a conformationally dynamic domain that complexes with transcriptional activators at two discrete binding sites in allosteric communication. The complexation of KIX with the transcriptional activation domain of mixed-lineage leukemia protein leads to an enhancement of binding by the activation domain of CREB (phosphorylated kinase-inducible domain of CREB) to the second site. A transient kinetic analysis of the ternary complex formation aided by small molecule ligands that induce positive or negative cooperative binding reveals that positive cooperativity is largely governed by stabilization of the bound complex as indicated by a decrease in koff. Thus, this suggests the increased binding affinity for the second ligand is not due to an allosteric creation of a more favorable binding interface by the first ligand. This is consistent with data from us and from others indicating that the on rates of conformationally dynamic proteins approach the limits of diffusion. In contrast, negative cooperativity is manifested by alterations in both kon and koff, suggesting stabilization of the binary complex. PMID:25049401

  15. Ablation of Steroid Receptor Coactivator-3 resembles the human CACT metabolic myopathy

    PubMed Central

    York, Brian; Reineke, Erin L.; Sagen, Jørn V.; Nikolai, Bryan C.; Zhou, Suoling; Louet, Jean-Francois; Chopra, Atul R.; Chen, Xian; Reed, Graham; Noebels, Jeffrey; Adesina, Adekunle M.; Yu, Hui; Wong, Lee-Jun C.; Tsimelzon, Anna; Hilsenbeck, Susan; Stevens, Robert D.; Wenner, Brett R.; Ilkayeva, Olga; Xu, Jianming; Newgard, Christopher B.; O’Malley, Bert W.

    2012-01-01

    Summary Oxidation of lipid substrates is essential for survival in fasting and other catabolic conditions, sparing glucose for the brain and other glucose-dependent tissues. Here we show Steroid Receptor Coactivator-3 (SRC-3) plays a central role in long chain fatty acid metabolism by directly regulating carnitine/acyl-carnitine translocase (CACT) gene expression. Genetic deficiency of CACT in humans is accompanied by a constellation of metabolic and toxicity phenotypes including hypoketonemia, hypoglycemia, hyperammonemia, and impaired neurologic, cardiac and skeletal muscle performance, each of which is apparent in mice lacking SRC-3 expression. Consistent with human cases of CACT deficiency, dietary rescue with short chain fatty acids drastically attenuates the clinical hallmarks of the disease in mice devoid of SRC-3. Collectively, our results position SRC-3 as a key regulator of β-oxidation. Moreover, these findings allow us to consider platform coactivators such as the SRCs as potential contributors to syndromes such as CACT deficiency, previously considered as monogenic. PMID:22560224

  16. PRMT4 is a novel coactivator of c-Myb-dependent transcription in haematopoietic cell lines.

    PubMed

    Streubel, Gundula; Bouchard, Caroline; Berberich, Hannah; Zeller, Marc S; Teichmann, Sophia; Adamkiewicz, Jürgen; Müller, Rolf; Klempnauer, Karl-Heinz; Bauer, Uta-Maria

    2013-01-01

    Protein arginine methyltransferase 4 (PRMT4)-dependent methylation of arginine residues in histones and other chromatin-associated proteins plays an important role in the regulation of gene expression. However, the exact mechanism of how PRMT4 activates transcription remains elusive. Here, we identify the chromatin remodeller Mi2α as a novel interaction partner of PRMT4. PRMT4 binds Mi2α and its close relative Mi2β, but not the other components of the repressive Mi2-containing NuRD complex. In the search for the biological role of this interaction, we find that PRMT4 and Mi2α/β interact with the transcription factor c-Myb and cooperatively coactivate c-Myb target gene expression in haematopoietic cell lines. This coactivation requires the methyltransferase and ATPase activity of PRMT4 and Mi2, respectively. Chromatin immunoprecipitation analysis shows that c-Myb target genes are direct transcriptional targets of PRMT4 and Mi2. Knockdown of PRMT4 or Mi2α/β in haematopoietic cells of the erythroid lineage results in diminished transcriptional induction of c-Myb target genes, attenuated cell growth and survival, and deregulated differentiation resembling the effects caused by c-Myb depletion. These findings reveal an important and so far unknown connection between PRMT4 and the chromatin remodeller Mi2 in c-Myb signalling. PMID:23505388

  17. Outdoor Play and Play Equipment.

    ERIC Educational Resources Information Center

    Naylor, Heather

    1985-01-01

    Discusses aspects of the play environment and its effect on children's play behavior. Indoor and outdoor play spaces are considered along with factors affecting the use of outdoor environments for play. Children's preferences for different outdoor play environments and for various play structures are explored. Guides for choosing play equipment…

  18. Steroid receptor coactivator 2 modulates steroid-dependent male sexual behavior and neuroplasticity in Japanese quail (Coturnix japonica).

    PubMed

    Niessen, Neville-Andrew; Balthazart, Jacques; Ball, Gregory F; Charlier, Thierry D

    2011-11-01

    Steroid receptor coactivators are necessary for efficient transcriptional regulation by ligand-bound nuclear receptors, including estrogen and androgen receptors. Steroid receptor coactivator-2 (SRC-2) modulates estrogen- and progesterone-dependent sexual behavior in female rats but its implication in the control of male sexual behavior has not been studied to our knowledge. We cloned and sequenced the complete quail SRC-2 transcript and showed by semi-quantitative PCR that SRC-2 expression is nearly ubiquitous, with high levels of expression in the kidney, cerebellum and diencephalon. Real-time quantitative PCR did not reveal any differences between intact males and females the medial preoptic nucleus (POM), optic lobes and cerebellum. We next investigated the physiological and behavioral role of this coactivator using in vivo antisense oligonucleotide techniques. Daily injections in the third ventricle at the level of the POM of locked nucleic acid antisense targeting SRC-2 significantly reduced the expression of testosterone-dependent male-typical copulatory behavior but no inhibition of one aspect of the appetitive sexual behavior was observed. The volume of POM, defined by aromatase-immunoreactive cells, was markedly decreased in animals treated with antisense as compared with controls. These results demonstrate that SRC-2 plays a prominent role in the control of steroid-dependent male sexual behavior and its associated neuroplasticity in Japanese quail. PMID:21854393

  19. Estrogen-related receptor alpha and PGC-1-related coactivator constitute a novel complex mediating the biogenesis of functional mitochondria.

    PubMed

    Mirebeau-Prunier, Delphine; Le Pennec, Soazig; Jacques, Caroline; Gueguen, Naig; Poirier, Julie; Malthiery, Yves; Savagner, Frédérique

    2010-02-01

    Mitochondrial biogenesis, which depends on nuclear as well as mitochondrial genes, occurs in response to increased cellular ATP demand. The nuclear transcriptional factors, estrogen-related receptor alpha (ERRalpha) and nuclear respiratory factors 1 and 2, are associated with the coordination of the transcriptional machinery governing mitochondrial biogenesis, whereas coactivators of the peroxisome proliferator-activated receptor gamma coactivator-1 (PGC-1) family serve as mediators between the environment and this machinery. In the context of proliferating cells, PGC-1-related coactivator (PRC) is a member of the PGC-1 family, which is known to act in partnership with nuclear respiratory factors, but no functional interference between PRC and ERRalpha has been described so far. We explored three thyroid cell lines, FTC-133, XTC.UC1 and RO 82 W-1, each characterized by a different mitochondrial content, and studied their behavior towards PRC and ERRalpha in terms of respiratory efficiency. Overexpression of PRC and ERRalpha led to increased respiratory chain capacity and mitochondrial mass. The inhibition of ERRalpha decreased cell growth and respiratory chain capacity in all three cell lines. However, the inhibition of PRC and ERRalpha produced a greater effect in the oxidative cell model, decreasing the mitochondrial mass and the phosphorylating respiration, whereas the nonphosphorylating respiration remained unchanged. We therefore hypothesize that the ERRalpha-PRC complex plays a role in arresting the cell cycle through the regulation of oxidative phosphorylation in oxidative cells, and through some other pathway in glycolytic cells. PMID:20067526

  20. Transcription Coactivators p300 and CBP Are Necessary for Photoreceptor-Specific Chromatin Organization and Gene Expression

    PubMed Central

    Hennig, Anne K.; Peng, Guang-Hua; Chen, Shiming

    2013-01-01

    Rod and cone photoreceptor neurons in the mammalian retina possess specialized cellular architecture and functional features for converting light to a neuronal signal. Establishing and maintaining these characteristics requires appropriate expression of a specific set of genes, which is tightly regulated by a network of photoreceptor transcription factors centered on the cone-rod homeobox protein CRX. CRX recruits transcription coactivators p300 and CBP to acetylate promoter-bound histones and activate transcription of target genes. To further elucidate the role of these two coactivators, we conditionally knocked out Ep300 and/or CrebBP in differentiating rods or cones, using opsin-driven Cre recombinase. Knockout of either factor alone exerted minimal effects, but loss of both factors severely disrupted target cell morphology and function: the unique nuclear chromatin organization seen in mouse rods was reversed, accompanied by redistribution of nuclear territories associated with repressive and active histone marks. Transcription of many genes including CRX targets was severely impaired, correlating with reduced histone H3/H4 acetylation (the products of p300/CBP) on target gene promoters. Interestingly, the presence of a single wild-type allele of either coactivator prevented many of these defects, with Ep300 more effective than Cbp. These results suggest that p300 and CBP play essential roles in maintaining photoreceptor-specific structure, function and gene expression. PMID:23922782

  1. New Play.

    ERIC Educational Resources Information Center

    Lersten, Kenneth C.

    There have been many theories and hypotheses about play, one of which is the equation of play with "transcendence." Play may have the ingredients to allow us to transcend and, for a moment, remythologize life. There have been recent authors who have given play the status of theology, indicating that play contains elements also found in religion.…

  2. Playful Gaming.

    ERIC Educational Resources Information Center

    Makedon, Alexander

    A philosophical analysis of play and games is undertaken in this paper. Playful gaming, which is shown to be a synthesis of play and games, is utilized as a category for undertaking the examination of play and games. The significance of playful gaming to education is demonstrated through analyses of Plato's, Dewey's, Sartre's, and Marcuse's…

  3. A polymorphism in the nuclear receptor coactivator 7 gene and breast cancer susceptibility.

    PubMed

    Süllner, Julia; Lattrich, Claus; Häring, Julia; Görse, Regina; Ortmann, Olaf; Treeck, Oliver

    2012-01-01

    The nuclear receptor coactivator 7 (NCoA7) gene codes for an estrogen receptor-associated protein that plays a significant role in the cellular response to estrogens. Given that NCoA7 is expressed in the mammary gland, alterations in this gene may affect breast cancer risk. In this study, we compared the genotype and allele frequencies of the missense single nucleotide polymorphism (SNP) rs1567, located in the coding region of the NCoA7 gene and resulting in an amino acid exchange from asparagine to glutamine, in 305 women with sporadic breast cancer and 346 women without any malignancy. Statistical analysis of the observed frequencies did not reveal a significant difference between the cancer and control groups, nor did a comparison between histological breast cancer subgroups. In conclusion, the results of our phenotype-genotype association study indicate that NCoA7 SNP rs1567 does not affect breast cancer susceptibility. PMID:22740868

  4. A polymorphism in the nuclear receptor coactivator 7 gene and breast cancer susceptibility

    PubMed Central

    SÜLLNER, JULIA; LATTRICH, CLAUS; HÄRING, JULIA; GÖRSE, REGINA; ORTMANN, OLAF; TREECK, OLIVER

    2012-01-01

    The nuclear receptor coactivator 7 (NCoA7) gene codes for an estrogen receptor-associated protein that plays a significant role in the cellular response to estrogens. Given that NCoA7 is expressed in the mammary gland, alterations in this gene may affect breast cancer risk. In this study, we compared the genotype and allele frequencies of the missense single nucleotide polymorphism (SNP) rs1567, located in the coding region of the NCoA7 gene and resulting in an amino acid exchange from asparagine to glutamine, in 305 women with sporadic breast cancer and 346 women without any malignancy. Statistical analysis of the observed frequencies did not reveal a significant difference between the cancer and control groups, nor did a comparison between histological breast cancer subgroups. In conclusion, the results of our phenotype-genotype association study indicate that NCoA7 SNP rs1567 does not affect breast cancer susceptibility. PMID:22740868

  5. Steroid receptor coactivator-3 regulates glucose metabolism in bladder cancer cells through coactivation of hypoxia inducible factor 1α.

    PubMed

    Zhao, Wei; Chang, Cunjie; Cui, Yangyan; Zhao, Xiaozhi; Yang, Jun; Shen, Lan; Zhou, Ji; Hou, Zhibo; Zhang, Zhen; Ye, Changxiao; Hasenmayer, Donald; Perkins, Robert; Huang, Xiaojing; Yao, Xin; Yu, Like; Huang, Ruimin; Zhang, Dianzheng; Guo, Hongqian; Yan, Jun

    2014-04-18

    Cancer cell proliferation is a metabolically demanding process, requiring high glycolysis, which is known as "Warburg effect," to support anabolic growth. Steroid receptor coactivator-3 (SRC-3), a steroid receptor coactivator, is overexpressed and/or amplified in multiple cancer types, including non-steroid targeted cancers, such as urinary bladder cancer (UBC). However, whether SRC-3 regulates the metabolic reprogramming for cancer cell growth is unknown. Here, we reported that overexpression of SRC-3 accelerated UBC cell growth, accompanied by the increased expression of genes involved in glycolysis. Knockdown of SRC-3 reduced the UBC cell glycolytic rate under hypoxia, decreased tumor growth in nude mice, with reduction of proliferating cell nuclear antigen and lactate dehydrogenase expression levels. We further revealed that SRC-3 could interact with hypoxia inducible factor 1α (HIF1α), which is a key transcription factor required for glycolysis, and coactivate its transcriptional activity. SRC-3 was recruited to the promoters of HIF1α-target genes, such as glut1 and pgk1. The positive correlation of expression levels between SRC-3 and Glut1 proteins was demonstrated in human UBC patient samples. Inhibition of glycolysis through targeting HK2 or LDHA decelerated SRC-3 overexpression-induced cell growth. In summary, overexpression of SRC-3 promoted glycolysis in bladder cancer cells through HIF1α to facilitate tumorigenesis, which may be an intriguing drug target for bladder cancer therapy. PMID:24584933

  6. Steroid Receptor Coactivator-3 Regulates Glucose Metabolism in Bladder Cancer Cells through Coactivation of Hypoxia Inducible Factor 1α*

    PubMed Central

    Zhao, Wei; Chang, Cunjie; Cui, Yangyan; Zhao, Xiaozhi; Yang, Jun; Shen, Lan; Zhou, Ji; Hou, Zhibo; Zhang, Zhen; Ye, Changxiao; Hasenmayer, Donald; Perkins, Robert; Huang, Xiaojing; Yao, Xin; Yu, Like; Huang, Ruimin; Zhang, Dianzheng; Guo, Hongqian; Yan, Jun

    2014-01-01

    Cancer cell proliferation is a metabolically demanding process, requiring high glycolysis, which is known as “Warburg effect,” to support anabolic growth. Steroid receptor coactivator-3 (SRC-3), a steroid receptor coactivator, is overexpressed and/or amplified in multiple cancer types, including non-steroid targeted cancers, such as urinary bladder cancer (UBC). However, whether SRC-3 regulates the metabolic reprogramming for cancer cell growth is unknown. Here, we reported that overexpression of SRC-3 accelerated UBC cell growth, accompanied by the increased expression of genes involved in glycolysis. Knockdown of SRC-3 reduced the UBC cell glycolytic rate under hypoxia, decreased tumor growth in nude mice, with reduction of proliferating cell nuclear antigen and lactate dehydrogenase expression levels. We further revealed that SRC-3 could interact with hypoxia inducible factor 1α (HIF1α), which is a key transcription factor required for glycolysis, and coactivate its transcriptional activity. SRC-3 was recruited to the promoters of HIF1α-target genes, such as glut1 and pgk1. The positive correlation of expression levels between SRC-3 and Glut1 proteins was demonstrated in human UBC patient samples. Inhibition of glycolysis through targeting HK2 or LDHA decelerated SRC-3 overexpression-induced cell growth. In summary, overexpression of SRC-3 promoted glycolysis in bladder cancer cells through HIF1α to facilitate tumorigenesis, which may be an intriguing drug target for bladder cancer therapy. PMID:24584933

  7. CRTC2 Is a Coactivator of GR and Couples GR and CREB in the Regulation of Hepatic Gluconeogenesis.

    PubMed

    Hill, Micah J; Suzuki, Shigeru; Segars, James H; Kino, Tomoshige

    2016-01-01

    Glucocorticoid hormones play essential roles in the regulation of gluconeogenesis in the liver, an adaptive response that is required for the maintenance of circulating glucose levels during fasting. Glucocorticoids do this by cooperating with glucagon, which is secreted from pancreatic islets to activate the cAMP-signaling pathway in hepatocytes. The cAMP-response element-binding protein (CREB)-regulated transcription coactivator 2 (CRTC2) is a coactivator known to be specific to CREB and plays a central role in the glucagon-mediated activation of gluconeogenesis in the early phase of fasting. We show here that CRTC2 also functions as a coactivator for the glucocorticoid receptor (GR). CRTC2 strongly enhances GR-induced transcriptional activity of glucocorticoid-responsive genes. CRTC2 physically interacts with the ligand-binding domain of the GR through a region spanning amino acids 561-693. Further, CRTC2 is required for the glucocorticoid-associated cooperative mRNA expression of the glucose-6-phosphatase, a rate-limiting enzyme for hepatic gluconeogenesis, by facilitating the attraction of GR and itself to its promoter region already occupied by CREB. CRTC2 is required for the maintenance of blood glucose levels during fasting in mice by enhancing the GR transcriptional activity on both the G6p and phosphoenolpyruvate carboxykinase (Pepck) genes. Finally, CRTC2 modulates the transcriptional activity of the progesterone receptor, indicating that it may influence the transcriptional activity of other steroid/nuclear receptors. Taken together, these results reveal that CRTC2 plays an essential role in the regulation of hepatic gluconeogenesis through coordinated regulation of the glucocorticoid/GR- and glucagon/CREB-signaling pathways on the key genes G6P and PEPCK. PMID:26652733

  8. Nuclear receptor coactivators: Regulators of steroid action in brain and behavior

    PubMed Central

    Tetel, Marc J.; Acharya, Kalpana D.

    2013-01-01

    Steroid hormones act in specific regions of the brain to alter behavior and physiology. While it has been well established that the bioavailability of the steroid and the expression of its receptor is critical to understanding steroid action in brain, the importance of nuclear receptor coactivators in brain is becoming more apparent. This review will focus on the function of the p160 family of coactivators, which includes steroid receptor coactivator-1 (SRC-1), SRC-2 and SRC-3, in steroid receptor action in brain. The expression, regulation and function of these coactivators in steroid-dependent gene expression in brain and behavior will be discussed. PMID:23795583

  9. Coactivator recruitment of AhR/ARNT1.

    PubMed

    Endler, Alexander; Chen, Li; Shibasaki, Futoshi

    2014-01-01

    A common feature of nuclear receptors (NRs) is the transformation of external cell signals into specific transcriptions of the signal molecule. Signal molecules function as ligands for NRs and, after their uptake, activated NRs form homo- or heterodimers at promoter recognition sequences of the specific genes in the nucleus. Another common feature of NRs is their dependence on coactivators, which bridge the basic transcriptional machinery and other cofactors to the target genes, in order to initiate transcription and to unwind histone-bound DNA for exposing additional promoter recognition sites via their histone acetyltransferase (HAT) function. In this review, we focus on our recent findings related to the recruitment of steroid receptor coactivator 1 (SRC1/NCoA1) by the estrogen receptor-α (ERα) and by the arylhydrocarbon receptor/arylhydrocarbon receptor nuclear translocator 1 (AhR/ARNT1) complex. We also describe the extension of our previously published findings regarding the binding between ARNT1.1 exon16 and SRC1e exon 21, via in silico analyses of androgen receptor (AR) NH2-carboxyl-terminal interactions, the results of which were verified by in vitro experiments. Based on these data, we suggest a newly derived tentative binding site of nuclear coactivator 2/glucocorticoid receptor interacting protein-1/transcriptional intermediary factor 2 (NCOA-2/ GRIP-1/TIF-2) for ARNT1.1 exon 16. Furthermore, results obtained by immunoprecipitation have revealed a second leucine-rich binding site for hARNT1.1 exon 16 in SRC1e exon 21 (LSSTDLL). Finally, we discuss the role of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) as an endocrine disruptor for estrogen related transcription. PMID:24950180

  10. Co-activation based parcellation of the human frontal pole.

    PubMed

    Ray, K L; Zald, D H; Bludau, S; Riedel, M C; Bzdok, D; Yanes, J; Falcone, K E; Amunts, K; Fox, P T; Eickhoff, S B; Laird, A R

    2015-12-01

    Historically, the human frontal pole (FP) has been considered as a single architectonic area. Brodmann's area 10 is located in the frontal lobe with known contributions in the execution of various higher order cognitive processes. However, recent cytoarchitectural studies of the FP in humans have shown that this portion of cortex contains two distinct cytoarchitectonic regions. Since architectonic differences are accompanied by differential connectivity and functions, the frontal pole qualifies as a candidate region for exploratory parcellation into functionally discrete sub-regions. We investigated whether this functional heterogeneity is reflected in distinct segregations within cytoarchitectonically defined FP-areas using meta-analytic co-activation based parcellation (CBP). The CBP method examined the co-activation patterns of all voxels within the FP as reported in functional neuroimaging studies archived in the BrainMap database. Voxels within the FP were subsequently clustered into sub-regions based on the similarity of their respective meta-analytically derived co-activation maps. Performing this CBP analysis on the FP via k-means clustering produced a distinct 3-cluster parcellation for each hemisphere corresponding to previously identified cytoarchitectural differences. Post-hoc functional characterization of clusters via BrainMap metadata revealed that lateral regions of the FP mapped to memory and emotion domains, while the dorso- and ventromedial clusters were associated broadly with emotion and social cognition processes. Furthermore, the dorsomedial regions contain an emphasis on theory of mind and affective related paradigms whereas ventromedial regions couple with reward tasks. Results from this study support previous segregations of the FP and provide meta-analytic contributions to the ongoing discussion of elucidating functional architecture within human FP. PMID:26254112

  11. Caught in the act: covalent cross-linking captures activator-coactivator interactions in vivo.

    PubMed

    Krishnamurthy, Malathy; Dugan, Amanda; Nwokoye, Adaora; Fung, Yik-Hong; Lancia, Jody K; Majmudar, Chinmay Y; Mapp, Anna K

    2011-12-16

    Currently there are few methods suitable for the discovery and characterization of transient, moderate affinity protein-protein interactions in their native environment, despite their prominent role in a host of cellular functions including protein folding, signal transduction, and transcriptional activation. Here we demonstrate that a genetically encoded photoactivatable amino acid, p-benzoyl-l-phenylalanine, can be used to capture transient and/or low affinity binding partners in an in vivo setting. In this study, we focused on ensnaring the coactivator binding partners of the transcriptional activator VP16 in S. cerevisiae. The interactions between transcriptional activators and coactivators in eukaryotes are moderate in affinity and short-lived, and due in part to these characteristics, identification of the direct binding partners of activators in vivo has met with only limited success. We find through in vivo photo-cross-linking that VP16 contacts the Swi/Snf chromatin-remodeling complex through the ATPase Snf2(BRG1/BRM) and the subunit Snf5 with two distinct regions of the activation domain. An analogous experiment with Gal4 reveals that Snf2 is also a target of this activator. These results suggest that Snf2 may be a valuable target for small molecule probe discovery given the prominent role the Swi/Snf complex family plays in development and in disease. More significantly, the successful implementation of the in vivo cross-linking methodology in this setting demonstrates that it can be applied to the discovery and characterization of a broad range of transient and/or modest affinity protein-protein interactions. PMID:21977905

  12. Sertad1 encodes a novel transcriptional co-activator of SMAD1 in mouse embryonic hearts

    SciTech Connect

    Peng, Yin; Zhao, Shaomin; Song, Langying; Wang, Manyuan; Jiao, Kai

    2013-11-29

    Highlights: •SERTAD1 interacts with SMAD1. •Sertad1 is expressed in mouse embryonic hearts. •SERTAD1 is localized in both cytoplasm and nucleus of cardiomyocytes. •SERTAD1 enhances expression of BMP target cardiogenic genes as a SMAD1 co-activator. -- Abstract: Despite considerable advances in surgical repairing procedures, congenital heart diseases (CHDs) remain the leading noninfectious cause of infant morbidity and mortality. Understanding the molecular/genetic mechanisms underlying normal cardiogenesis will provide essential information for the development of novel diagnostic and therapeutic strategies against CHDs. BMP signaling plays complex roles in multiple cardiogenic processes in mammals. SMAD1 is a canonical nuclear mediator of BMP signaling, the activity of which is critically regulated through its interaction partners. We screened a mouse embryonic heart yeast two-hybrid library using Smad1 as bait and identified SERTAD1 as a novel interaction partner of SMAD1. SERTAD1 contains multiple potential functional domains, including two partially overlapping transactivation domains at the C terminus. The SERTAD1-SMAD1 interaction in vitro and in mammalian cells was further confirmed through biochemical assays. The expression of Sertad1 in developing hearts was demonstrated using RT-PCR, western blotting and in situ hybridization analyses. We also showed that SERTAD1 was localized in both the cytoplasm and nucleus of immortalized cardiomyocytes and primary embryonic cardiomyocyte cultures. The overexpression of SERTAD1 in cardiomyocytes not only enhanced the activity of two BMP reporters in a dose-dependent manner but also increased the expression of several known BMP/SMAD regulatory targets. Therefore, these data suggest that SERTAD1 acts as a SMAD1 transcriptional co-activator to promote the expression of BMP target genes during mouse cardiogenesis.

  13. Exploration of dimensions of estrogen potency: parsing ligand binding and coactivator binding affinities.

    PubMed

    Jeyakumar, M; Carlson, Kathryn E; Gunther, Jillian R; Katzenellenbogen, John A

    2011-04-15

    The estrogen receptors, ERα and ERβ, are ligand-regulated transcription factors that control gene expression programs in target tissues. The molecular events underlying estrogen action involve minimally two steps, hormone binding to the ER ligand-binding domain followed by coactivator recruitment to the ER·ligand complex; this ligand·receptor·coactivator triple complex then alters gene expression. Conceptually, the potency of an estrogen in activating a cellular response should reflect the affinities that characterize both steps involved in the assembly of the active ligand·receptor·coactivator complex. Thus, to better understand the molecular basis of estrogen potency, we developed a completely in vitro system (using radiometric and time-resolved FRET assays) to quantify independently three parameters: (a) the affinity of ligand binding to ER, (b) the affinity of coactivator binding to the ER·ligand complex, and (c) the potency of ligand recruitment of coactivator. We used this system to characterize the binding and potency of 12 estrogens with both ERα and ERβ. Some ligands showed good correlations between ligand binding affinity, coactivator binding affinity, and coactivator recruitment potency with both ERs, whereas others showed correlations with only one ER subtype or displayed discordant coactivator recruitment potencies. When ligands with low receptor binding affinity but high coactivator recruitment potencies to ERβ were evaluated in cell-based assays, elevation of cellular coactivator levels significantly and selectively improved their potency. Collectively, our results indicate that some low affinity estrogens may elicit greater cellular responses in those target cells that express higher levels of specific coactivators capable of binding to their ER complexes with high affinity. PMID:21321128

  14. Adult Play.

    ERIC Educational Resources Information Center

    Charles, John M.

    In its broadest context, play can be interpreted as any pleasurable use of discretionary time. Playfulness is an intrinsic feature of being human, and should be viewed in the light of a total lifestyle, not as an occurrence in an isolated time of life. Adult play appears to be an indefinable and controversial concept. A holistic approach should be…

  15. Wanna Play?

    ERIC Educational Resources Information Center

    Chenfeld, Mimi Brodsky

    2006-01-01

    In this article, the author talks about the importance of play in the lives of children and describes how games and imaginative play contribute to the development of children. From her decades-old collection of countless incidents demonstrating children's love for self-directed, informal, imaginative play, the author shares three incidents that…

  16. City Play.

    ERIC Educational Resources Information Center

    Dargan, Amanda; Zeitlin, Steve

    2000-01-01

    Today, fewer city blocks preserve the confidence of lifestyle and urban geography that sustain traditional games and outdoor play. Large groups of children choosing sides and organizing Red Rover games are no longer commonplace. Teachers must encourage free play; urban planners must build cities that are safe play havens. (MLH)

  17. Measuring Mathematics Teachers' Professional Competence by Using Video Clips (COACTIV Video)

    ERIC Educational Resources Information Center

    Bruckmaier, G.; Krauss, S.; Blum, W.; Leiss, D.

    2016-01-01

    The COACTIV video study is part of the COACTIV research program in which secondary mathematics teachers whose students participated in PISA 03/04 were examined, with respect to their professional knowledge, motivational orientations, beliefs, and self-regulation. In the video study, 284 German secondary mathematics teachers were asked to specify…

  18. Coactivation of Lower Limb Muscles during Gait in Patients with Multiple Sclerosis

    PubMed Central

    Boudarham, Julien; Hameau, Sophie; Zory, Raphael; Hardy, Alexandre; Bensmail, Djamel; Roche, Nicolas

    2016-01-01

    Background Coactivation of agonist and antagonist lower limb muscles during gait stiffens joints and ensures stability. In patients with multiple sclerosis, coactivation of lower limb muscles might be a compensatory mechanism to cope with impairments of balance and gait. Objective The aim of this study was to assess coactivation of agonist and antagonist muscles at the knee and ankle joints during gait in patients with multiple sclerosis, and to evaluate the relationship between muscle coactivation and disability, gait performance, dynamic ankle strength measured during gait, and postural stability. Methods The magnitude and duration of coactivation of agonist-antagonist muscle pairs at the knee and ankle were determined for both lower limbs (more and less-affected) in 14 patients with multiple sclerosis and 11 healthy subjects walking at a spontaneous speed, using 3D-gait analysis. Results In the patient group, coactivation was increased in the knee muscles during single support (proximal strategy) and in the ankle muscles during double support (distal strategy). The magnitude of coactivation was highest in the patients with the slowest gait, the greatest motor impairment and the most instability. Conclusion Increased muscle coactivation is likely a compensatory mechanism to limit the number of degrees of freedom during gait in patients with multiple sclerosis, particularly when postural stability is impaired. PMID:27336442

  19. Pontin functions as an essential coactivator for Oct4-dependent lincRNA expression in mouse embryonic stem cells.

    PubMed

    Boo, Kyungjin; Bhin, Jinhyuk; Jeon, Yoon; Kim, Joomyung; Shin, Hi-Jai R; Park, Jong-Eun; Kim, Kyeongkyu; Kim, Chang Rok; Jang, Hyonchol; Kim, In-Hoo; Kim, V Narry; Hwang, Daehee; Lee, Ho; Baek, Sung Hee

    2015-01-01

    The actions of transcription factors, chromatin modifiers and noncoding RNAs are crucial for the programming of cell states. Although the importance of various epigenetic machineries for controlling pluripotency of embryonic stem (ES) cells has been previously studied, how chromatin modifiers cooperate with specific transcription factors still remains largely elusive. Here, we find that Pontin chromatin remodelling factor plays an essential role as a coactivator for Oct4 for maintenance of pluripotency in mouse ES cells. Genome-wide analyses reveal that Pontin and Oct4 share a substantial set of target genes involved in ES cell maintenance. Intriguingly, we find that the Oct4-dependent coactivator function of Pontin extends to the transcription of large intergenic noncoding RNAs (lincRNAs) and in particular linc1253, a lineage programme repressing lincRNA, is a Pontin-dependent Oct4 target lincRNA. Together, our findings demonstrate that the Oct4-Pontin module plays critical roles in the regulation of genes involved in ES cell fate determination. PMID:25857206

  20. Regional specific regulation of steroid receptor coactivator-1 immunoreactivity by orchidectomy in the brain of adult male mice.

    PubMed

    Bian, Chen; Zhang, Kaiyuan; Zhao, Yangang; Guo, Qiang; Cai, Wenqin; Zhang, Jiqiang

    2014-10-01

    Androgens including testosterone and dihydrotestosterone play important roles on brain structure and function, either directly through androgen receptor or indirectly through estrogen receptors, which need coactivators for their transcription activation. Steroid receptor coactivator-1 (SRC-1) has been shown to be multifunctional potentials in the brain, but how it is regulated by androgens in the brain remains unclear. In this study, we explored the effect of orchidectomy (ORX) on the expression of SRC-1 in the adult male mice using nickel-intensified immunohistochemistry. The results showed that ORX induced dramatic decrease of SRC-1 immunoreactivity in the olfactory tubercle, piriform cortex, ventral pallidum, most parts of the septal area, hippocampus, substantia nigra (compact part), pontine nuclei and nucleus of the trapezoid body (p<0.01). Significant decrease of SRC-1 was noticed in the dorsal and lateral septal nucleus, medial preoptical area, dorsomedial and ventromedial hypothalamic nucleus and superior paraolivary nucleus (p<0.05). Whereas in other regions examined, levels of SRC-1 immunoreactivity were not obviously changed by ORX (p>0.05). The above results demonstrated ORX downregulation of SRC-1 in specific regions that have been involved in sense of smell, learning and memory, cognition, neuroendocrine, reproduction and motor control, indicating that SRC-1 play pivotal role in the mediating circulating androgenic regulation on these important brain functions. It also indicates that SRC-1 may serve as a novel target for the central disorders caused by the age-related decrease of circulating androgens. PMID:24945110

  1. Pretend play.

    PubMed

    Weisberg, Deena Skolnick

    2015-01-01

    Pretend play is a form of playful behavior that involves nonliteral action. Although on the surface this activity appears to be merely for fun, recent research has discovered that children's pretend play has connections to important cognitive and social skills, such as symbolic thinking, theory of mind, and counterfactual reasoning. The current article first defines pretend play and then reviews the arguments and evidence for these three connections. Pretend play has a nonliteral correspondence to reality, hence pretending may provide children with practice with navigating symbolic relationships, which may strengthen their language skills. Pretend play and theory of mind reasoning share a focus on others' mental states in order to correctly interpret their behavior, hence pretending and theory of mind may be mutually supportive in development. Pretend play and counterfactual reasoning both involve representing nonreal states of affairs, hence pretending may facilitate children's counterfactual abilities. These connections make pretend play an important phenomenon in cognitive science: Studying children's pretend play can provide insight into these other abilities and their developmental trajectories, and thereby into human cognitive architecture and its development. PMID:26263228

  2. Expression, purification, crystallization and preliminary crystallographic study of isolated modules of the mouse coactivator-associated arginine methyltransferase 1

    SciTech Connect

    Troffer-Charlier, Nathalie; Cura, Vincent; Hassenboehler, Pierre; Moras, Dino; Cavarelli, Jean

    2007-04-01

    Isolated modules of mouse coactivator-associated arginine methyltransferase 1 encompassing the protein arginine N-methyltransferase catalytic domain have been overexpressed, purified and crystallized. X-ray diffraction data have been collected and have enabled determination of the structures by multiple isomorphous replacement using anomalous scattering. Coactivator-associated arginine methyltransferase 1 (CARM1) plays a crucial role in gene expression as a coactivator of several nuclear hormone receptors and also of non-nuclear receptor systems. Its recruitment by the transcriptional machinery induces protein methylation, leading to chromatin remodelling and gene activation. CARM1{sub 28–507} and two structural states of CARM1{sub 140–480} were expressed, purified and crystallized. Crystals of CARM1{sub 28–507} belong to space group P6{sub 2}22, with unit-cell parameters a = b = 136.0, c = 125.3 Å; they diffract to beyond 2.5 Å resolution using synchrotron radiation and contain one monomer in the asymmetric unit. The structure of CARM1{sub 28–507} was solved by multiple isomorphous replacement and anomalous scattering methods. Crystals of apo CARM1{sub 140–480} belong to space group I222, with unit-cell parameters a = 74.6, b = 99.0, c = 207.4 Å; they diffract to beyond 2.7 Å resolution and contain two monomers in the asymmetric unit. Crystals of CARM1{sub 140–480} in complex with S-adenosyl-l-homocysteine belong to space P2{sub 1}2{sub 1}2, with unit-cell parameters a = 74.6, b = 98.65, c = 206.08 Å; they diffract to beyond 2.6 Å resolution and contain four monomers in the asymmetric unit. The structures of apo and holo CARM1{sub 140–480} were solved by molecular-replacement techniques from the structure of CARM1{sub 28–507}.

  3. PGC-1 coactivators in β-cells regulate lipid metabolism and are essential for insulin secretion coupled to fatty acids

    PubMed Central

    Oropeza, Daniel; Jouvet, Nathalie; Bouyakdan, Khalil; Perron, Gabrielle; Ringuette, Lea-Jeanne; Philipson, Louis H.; Kiss, Robert S.; Poitout, Vincent; Alquier, Thierry; Estall, Jennifer L.

    2015-01-01

    Objectives Peroxisome proliferator-activated receptor γ coactivator 1 (PPARGCA1, PGC-1) transcriptional coactivators control gene programs important for nutrient metabolism. Islets of type 2 diabetic subjects have reduced PGC-1α expression and this is associated with decreased insulin secretion, yet little is known about why this occurs or what role it plays in the development of diabetes. Our goal was to delineate the role and importance of PGC-1 proteins to β-cell function and energy homeostasis. Methods We investigated how nutrient signals regulate coactivator expression in islets and the metabolic consequences of reduced PGC-1α and PGC-1β in primary and cultured β-cells. Mice with inducible β-cell specific double knockout of Pgc-1α/Pgc-1β (βPgc-1 KO) were created to determine the physiological impact of reduced Pgc1 expression on glucose homeostasis. Results Pgc-1α and Pgc-1β expression was increased in primary mouse and human islets by acute glucose and palmitate exposure. Surprisingly, PGC-1 proteins were dispensable for the maintenance of mitochondrial mass, gene expression, and oxygen consumption in response to glucose in adult β-cells. However, islets and mice with an inducible, β-cell-specific PGC-1 knockout had decreased insulin secretion due in large part to loss of the potentiating effect of fatty acids. Consistent with an essential role for PGC-1 in lipid metabolism, β-cells with reduced PGC-1s accumulated acyl-glycerols and PGC-1s controlled expression of key enzymes in lipolysis and the glycerolipid/free fatty acid cycle. Conclusions These data highlight the importance of PGC-1s in coupling β-cell lipid metabolism to promote efficient insulin secretion. PMID:26629405

  4. Shadow Play

    ERIC Educational Resources Information Center

    Trundle, Kathy Cabe; Hilson, Margilee P.

    2012-01-01

    A bunny rabbit playfully hops across the wall. Then hands realign and fingers shift to make a hawk soar toward the ceiling. Most children have enjoyed the delightful experience of playing with shadow puppets. The authors build on this natural curiosity to help students link shadows to complex astronomical concepts such as seasons. The…

  5. Transcriptional Activation of Human Matrix Metalloproteinase-9 Gene Expression by Multiple Coactivators

    PubMed Central

    Zhao, Xueyan; Benveniste, Etty N.

    2008-01-01

    Summary Matrix metalloproteinase-9 (MMP-9), a proteolytic enzyme for matrix proteins, chemokines and cytokines, is a major target in cancer and autoimmune diseases since it is aberrantly upregulated. To control MMP-9 expression in pathological conditions, it is necessary to understand the regulatory mechanisms of MMP-9 expression. MMP-9 gene expression is regulated primarily at the transcriptional level. In this study, we investigated the role of multiple coactivators in regulating MMP-9 transcription. We demonstrate that multiple transcriptional coactivators are involved in MMP-9 promoter activation, including CBP/p300, PCAF, CARM1 and GRIP1. Furthermore, enhancement of MMP-9 promoter activity requires the histone acetyltransferase activity of PCAF but not that of CBP/p300, and the methyltransferase activity of CARM1. More importantly, these coactivators are not only able to activate MMP-9 promoter activity independently, but also function in a synergistic manner. Significant synergy was observed among CARM1, p300 and GRIP1, which is dependent on the interaction of p300 and CARM1 with the AD1 and AD2 domains of GRIP1, respectively. This suggests the formation of a ternary coactivator complex on the MMP-9 promoter. Chromatin immunoprecipitation assays demonstrate that these coactivators associate with the endogenous MMP-9 promoter, and that siRNA knockdown of expression of these coactivators reduces endogenous MMP-9 expression. Taken together, these studies demonstrate a new level of transcriptional regulation of MMP-9 expression by the cooperative action of coactivators. PMID:18790699

  6. On the way of revealing coactivator complexes cross-talk during transcriptional activation.

    PubMed

    Krasnov, Aleksey N; Mazina, Marina Yu; Nikolenko, Julia V; Vorobyeva, Nadezhda E

    2016-01-01

    Transcriptional activation is a complex, multistage process implemented by hundreds of proteins. Many transcriptional proteins are organized into coactivator complexes, which participate in transcription regulation at numerous genes and are a driver of this process. The molecular action mechanisms of coactivator complexes remain largely understudied. Relevant publications usually deal with the involvement of these complexes in the entire process of transcription, and only a few studies are aimed to elucidate their functions at its particular stages. This review summarizes available information on the participation of key coactivator complexes in transcriptional activation. The timing of coactivator complex binding/removal has been used for restructuring previously described information about the transcriptional process. Several major stages of transcriptional activation have been distinguished based on the presence of covalent histone modifications and general transcriptional factors, and the recruitment and/or removal phases have been determined for each coactivator included in analysis. Recruitment of Mediator, SWItch/Sucrose Non-Fermentable and NUcleosome Remodeling Factor complexes during transcription activation has been investigated thoroughly; CHD and INOsitol auxotrophy 80 families are less well studied. In most cases, the molecular mechanisms responsible for the removal of certain coactivator complexes after the termination of their functions at the promoters are still not understood. On the basis of the summarized information, we propose a scheme that illustrates the involvement of coactivator complexes in different stages of the transcription activation process. This scheme may help to gain a deeper insight into the molecular mechanism of functioning of coactivator complexes, find novel participants of the process, and reveal novel structural or functional connections between different coactivators. PMID:26913181

  7. Expression, purification and primary crystallographic study of human androgen receptor in complex with DNA and coactivator motifs

    SciTech Connect

    Zhou, X. Edward; Suino-Powell, Kelly; Ludidi, Phumzile L.; McDonnell, Donald P.; Xu, H. Eric

    2012-10-24

    The androgen receptor (AR) is a DNA-binding and hormone-activated transcription factor that plays critical roles in the development and progression of prostate cancer. The transcriptional function of AR is modulated by intermolecular interactions with DNA elements and coactivator proteins, as well as intramolecular interactions between AR domains; thus, the structural information from the full-length AR or a multi-domain fragment is essential for understanding the molecular basis of AR functions. Here we report the expression and purification of full-length AR protein and of a fragment containing its DNA-binding and ligand-binding domains connected by the hinge region in the presence of its natural ligand, dihydrotestosterone. Crystals of ligand-bound full-length AR and of the AR fragment in complex with DNA elements and coactivator motifs have been obtained and diffracted to low resolutions. These results help establish a foundation for pursuing further crystallographic studies of an AR/DNA complex.

  8. STEROID RECEPTOR COACTIVATOR 2 (SRC-2) MODULATES STEROID-DEPENDENT MALE SEXUAL BEHAVIOR AND NEUROPLASTICITY IN JAPANESE QUAIL (COTURNIX JAPONICA)

    PubMed Central

    Niessen, Neville-Andrew; Balthazart, Jacques; Ball, Gregory F.; Charlier, Thierry D.

    2011-01-01

    Steroid receptor coactivators are necessary for efficient transcriptional regulation by ligand-bound nuclear receptors, including estrogen and androgen receptors. SRC-2 modulates estrogen- and progesterone-dependent sexual behavior in female rats but its implication in the control of male sexual behavior has not been studied to our knowledge. We cloned and sequenced the complete quail SRC-2 transcript and showed by semi-quantitative PCR that SRC-2 expression is nearly ubiquitous, with high levels of expression in the kidney, cerebellum and diencephalon. Real time quantitative PCR did not reveal any differences between intact males and females the medial preoptic nucleus (POM), optic lobes and cerebellum. We next investigated the physiological and behavioral role of this coactivator using in vivo antisense oligonucleotide (AS) techniques. Daily injections in the third ventricle at the level of the POM of locked nucleic acid antisense targeting SRC-2 significantly reduced the expression of testosterone-dependent male-typical copulatory behavior but no inhibition of one aspect of the appetitive sexual behavior was observed. The volume of POM, defined by aromatase-immunoreactive cells, was markedly decreased in animals treated with AS as compared to controls. These results demonstrate that SRC-2 plays a prominent role in the control of steroid-dependent male sexual behavior and its associated neuroplasticity in Japanese quail. PMID:21854393

  9. Amphipathic Benzenes Are Designed Inhibitors of the Estrogen Receptor α/Steroid Receptor Coactivator Interaction

    PubMed Central

    Gunther, Jillian R.; Moore, Terry W.; Collins, Margaret L.; Katzenellenbogen, John A.

    2008-01-01

    We report here on the design, synthesis and evaluation of small molecule inhibitors of the interaction between a steroid receptor coactivator and estrogen receptor α. These inhibitors are based upon an amphipathic benzene scaffold whose hydrophobic face mimics the leucine-rich α-helical consensus sequence on the steroid receptor coactivators that interacts with a shallow groove on estrogen receptor α. Several of these molecules are among the most potent inhibitors of this interaction described to date, and they are active at low micromolar concentrations in both in vitro models of estrogen receptor action and in cell-based assays of estrogen receptor-mediated coactivator interaction and transcription. PMID:18484708

  10. Nuclear receptor coactivators: Essential players in steroid hormone action in brain and behavior

    PubMed Central

    Tetel, Marc J.

    2009-01-01

    Steroid hormones act in brain and throughout the body to influence behavior and physiology. Many of these effects of steroid hormones are elicited by transcriptional events mediated by their respective receptors. A variety of cell culture studies reveal that nuclear receptor coactivators are critical in modulating steroid receptor-dependent transcription. Thus, in addition to the availability of the hormone and the expression of its receptor, nuclear receptor coactivators are essential for steroid-dependent transactivation of genes. This review will discuss the mounting evidence that nuclear receptor coactivators are critical in modulating steroid hormone action in brain and the regulation of behavior. PMID:19207820

  11. Clay Play

    ERIC Educational Resources Information Center

    Rogers, Liz; Steffan, Dana

    2009-01-01

    This article describes how to use clay as a potential material for young children to explore. As teachers, the authors find that their dialogue about the potential of clay as a learning medium raises many questions: (1) What makes clay so enticing? (2) Why are teachers noticing different play and conversation around the clay table as compared to…

  12. Playing Teacher.

    ERIC Educational Resources Information Center

    Gilbert, Juan E.

    The acceptance of animation technologies is increasing. Video games, such as Sony PlayStation (SONY, 2002), have become part of the culture for young people from kindergarten through undergraduate school. Animation technologies have been implemented into educational systems in the form of animated pedagogical agents (Johnson, 2000). The research…

  13. Game playing.

    PubMed

    Rosin, Christopher D

    2014-03-01

    Game playing has been a core domain of artificial intelligence research since the beginnings of the field. Game playing provides clearly defined arenas within which computational approaches can be readily compared to human expertise through head-to-head competition and other benchmarks. Game playing research has identified several simple core algorithms that provide successful foundations, with development focused on the challenges of defeating human experts in specific games. Key developments include minimax search in chess, machine learning from self-play in backgammon, and Monte Carlo tree search in Go. These approaches have generalized successfully to additional games. While computers have surpassed human expertise in a wide variety of games, open challenges remain and research focuses on identifying and developing new successful algorithmic foundations. WIREs Cogn Sci 2014, 5:193-205. doi: 10.1002/wcs.1278 CONFLICT OF INTEREST: The author has declared no conflicts of interest for this article. For further resources related to this article, please visit the WIREs website. PMID:26304308

  14. Sweet Play

    ERIC Educational Resources Information Center

    Leung, Shuk-kwan S.; Lo, Jane-Jane

    2010-01-01

    This article features Sweet play math, a "math by the month" activity that involves decorating and making sugar cubes. Teachers may want to substitute straws, paper squares, alphabet blocks, or such commercially made manipulatives as Unifix[R] cubes for the real sweets. Given no allergy concerns, teachers and students alike would enjoy some sweet…

  15. All in the Family: A Portrait of a Nuclear Receptor Co-activator Complex

    PubMed Central

    Fant, Charli B.; Taatjes, Dylan J.

    2016-01-01

    In this issue of Molecular Cell, Chiu, O’Malley, and co-workers use biochemical assays and cryo-EM to determine the molecular architecture of an estrogen receptor (ERα) co-activator complex bound to DNA. PMID:25794613

  16. Steroid receptor coactivator-3 promotes bladder cancer through upregulation of CXCR4.

    PubMed

    Zhang, Yu; Wang, Ji-Hong; Liu, Bin; Qu, Ping-Bao

    2013-01-01

    The three homologous members of the p160 SRC family (SRC-1, SRC-2 and SRC-3) mediate the transcriptional functions of nuclear receptors and other transcription factors, and are the most studied of all the transcriptional co-activators. Recent work has indicated that the SRC-3 gene is subject to amplification and overexpression in various human cancers. Some of the molecular mechanisms responsible for SRC overexpression, along with the mechanisms by which SRC-3 promotes breast and prostate cancer cell proliferation and survival, have been identified. However, the function of SRC-3 in bladder cancer remains poorly understood. In the present study, our results indicate that overexpression of SRC-3 promotes bladder cancer cell proliferation whereas knockdown of SRC-3 results in inhibition. At the molecular level, we further established that CXCR4 is a transcriptional target of SRC-3. Therefore, our study first identified that SRC-3 plays a critical role in the bladder cancer, which may be a target beneficial for its prevention and treatment. PMID:23886194

  17. PADI4 acts as a coactivator of Tal1 by counteracting repressive histone arginine methylation.

    PubMed

    Kolodziej, Stephan; Kuvardina, Olga N; Oellerich, Thomas; Herglotz, Julia; Backert, Ingo; Kohrs, Nicole; Buscató, Estel la; Wittmann, Sandra K; Salinas-Riester, Gabriela; Bonig, Halvard; Karas, Michael; Serve, Hubert; Proschak, Ewgenij; Lausen, Jörn

    2014-01-01

    The transcription factor Tal1 is a critical activator or repressor of gene expression in hematopoiesis and leukaemia. The mechanism by which Tal1 differentially influences transcription of distinct genes is not fully understood. Here we show that Tal1 interacts with the peptidylarginine deiminase IV (PADI4). We demonstrate that PADI4 can act as an epigenetic coactivator through influencing H3R2me2a. At the Tal1/PADI4 target gene IL6ST the repressive H3R2me2a mark triggered by PRMT6 is counteracted by PADI4, which augments the active H3K4me3 mark and thus increases IL6ST expression. In contrast, at the CTCF promoter PADI4 acts as a repressor. We propose that the influence of PADI4 on IL6ST transcription plays a role in the control of IL6ST expression during lineage differentiation of hematopoietic stem/progenitor cells. These results open the possibility to pharmacologically influence Tal1 in leukaemia. PMID:24874575

  18. PADI4 acts as a coactivator of Tal1 by counteracting repressive histone arginine methylation

    PubMed Central

    Kolodziej, Stephan; Kuvardina, Olga N.; Oellerich, Thomas; Herglotz, Julia; Backert, Ingo; Kohrs, Nicole; Buscató, Estel.la; Wittmann, Sandra K.; Salinas-Riester, Gabriela; Bonig, Halvard; Karas, Michael; Serve, Hubert; Proschak, Ewgenij; Lausen, Jörn

    2014-01-01

    The transcription factor Tal1 is a critical activator or repressor of gene expression in hematopoiesis and leukaemia. The mechanism by which Tal1 differentially influences transcription of distinct genes is not fully understood. Here we show that Tal1 interacts with the peptidylarginine deiminase IV (PADI4). We demonstrate that PADI4 can act as an epigenetic coactivator through influencing H3R2me2a. At the Tal1/PADI4 target gene IL6ST the repressive H3R2me2a mark triggered by PRMT6 is counteracted by PADI4, which augments the active H3K4me3 mark and thus increases IL6ST expression. In contrast, at the CTCF promoter PADI4 acts as a repressor. We propose that the influence of PADI4 on IL6ST transcription plays a role in the control of IL6ST expression during lineage differentiation of hematopoietic stem/progenitor cells. These results open the possibility to pharmacologically influence Tal1 in leukaemia. PMID:24874575

  19. Identification and expression of an encoding steroid receptor coactivator (SRA) in amphioxus (Branchiostoma japonicum).

    PubMed

    Sun, Huanhuan; Gao, Lili; Pang, Qiuxiang; Sun, Lele; Wu, Di; Bai, Yun; Zhao, Bosheng; Dong, Juan

    2013-11-01

    Steroid receptor coactivator (SRA), a class of genes encoding both functional RNA and protein, has been shown to be present in vertebrates but little is known in invertebrates. Here we isolated a cDNA encoding a SRA homolog from amphioxus Branchiostoma japonicum, named AmphiSRA. The cDNA contained a 525 bp open reading frame corresponding to a deduced protein of 174 amino acids with a predicted molecular mass of ~21 kDa. Phylogenetic analysis showed that AmphiSRA was located at the base of its vertebrate counterparts, suggesting that it represents the archetype of vertebrate SRA. The genomic DNA sequence of AmphiSRA contained four exons and three introns, which was similar to B. floridae SRA exon/intron organization. The recombinant SRAP expressed in vitro shows a band with a molecular mass of 21 kDa and western blot confirmed it, which proved it is an encoding isoform. AmphiSRA is found to display a tissue specific expression pattern, with a predominant expression in gill, intestine, testis, neural tube and notochord. The whole-mount in situ hybridization demonstrated the expression of AmphiSRA in all the stages of development assayed. These implicated that SRA maybe play an important role during embryonic development of cephalochordate amphioxus. PMID:24065542

  20. Cellular Energy Depletion Resets Whole-Body Energy by Promoting Coactivator Mediated Dietary Fuel Absorption

    PubMed Central

    Chopra, Atul R.; Kommagani, Ramakrishna; Saha, Pradip; Louet, Jean-Francois; Salazar, Christina; Song, Junghun; Jeong, Jaewook; Finegold, Milton; Viollet, Benoit; DeMayo, Franco; Chan, Lawrence; Moore, David D.; O'Malley, Bert W.

    2010-01-01

    Summary All organisms have devised strategies to counteract energy depletion in order to promote fitness for survival. We show here that cellular energy depletion puts into play a surprising strategy that leads to absorption of exogenous fuel for energy repletion. We found that the energy depletion sensing kinase AMPK, binds, phosphorylates, and activates the transcriptional coactivator SRC-2, which in a liver-specific manner, promotes absorption of dietary fat from the gut. Hepatocyte-specific deletion of SRC-2 results in intestinal fat malabsorption and attenuated entry of fat into the blood stream. This defect can be attributed to AMPK and SRC-2 mediated transcriptional regulation of hepatic bile-acid secretion into the gut, as it can be completely rescued by replenishing intestinal BA, or by genetically restoring the levels of hepatic Bile Salt Export Pump (BSEP). Our results position the hepatic AMPK-SRC-2 axis as an energy rheostat which upon cellular energy depletion resets whole-body energy by promoting absorption of dietary fuel. PMID:21195347

  1. SRC-2 Coactivator Deficiency Decreases Functional Reserve in Response to Pressure Overload of Mouse Heart

    PubMed Central

    Reineke, Erin L.; York, Brian; Stashi, Erin; Chen, Xian; Tsimelzon, Anna; Xu, Jianming; Newgard, Christopher B.; Taffet, George E.; Taegtmeyer, Heinrich; Entman, Mark L.; O’Malley, Bert W.

    2012-01-01

    A major component of the cardiac stress response is the simultaneous activation of several gene regulatory networks. Interestingly, the transcriptional regulator steroid receptor coactivator-2, SRC-2 is often decreased during cardiac failure in humans. We postulated that SRC-2 suppression plays a mechanistic role in the stress response and that SRC-2 activity is an important regulator of the adult heart gene expression profile. Genome-wide microarray analysis, confirmed with targeted gene expression analyses revealed that genetic ablation of SRC-2 activates the “fetal gene program” in adult mice as manifested by shifts in expression of a) metabolic and b) sarcomeric genes, as well as associated modulating transcription factors. While these gene expression changes were not accompanied by changes in left ventricular weight or cardiac function, imposition of transverse aortic constriction (TAC) predisposed SRC-2 knockout (KO) mice to stress-induced cardiac dysfunction. In addition, SRC-2 KO mice lacked the normal ventricular hypertrophic response as indicated through heart weight, left ventricular wall thickness, and blunted molecular signaling known to activate hypertrophy. Our results indicate that SRC-2 is involved in maintenance of the steady-state adult heart transcriptional profile, with its ablation inducing transcriptional changes that mimic a stressed heart. These results further suggest that SRC-2 deletion interferes with the timing and integration needed to respond efficiently to stress through disruption of metabolic and sarcomeric gene expression and hypertrophic signaling, the three key stress responsive pathways. PMID:23300926

  2. PADI4 acts as a coactivator of Tal1 by counteracting repressive histone arginine methylation

    NASA Astrophysics Data System (ADS)

    Kolodziej, Stephan; Kuvardina, Olga N.; Oellerich, Thomas; Herglotz, Julia; Backert, Ingo; Kohrs, Nicole; Buscató, Estel. La; Wittmann, Sandra K.; Salinas-Riester, Gabriela; Bonig, Halvard; Karas, Michael; Serve, Hubert; Proschak, Ewgenij; Lausen, Jörn

    2014-05-01

    The transcription factor Tal1 is a critical activator or repressor of gene expression in hematopoiesis and leukaemia. The mechanism by which Tal1 differentially influences transcription of distinct genes is not fully understood. Here we show that Tal1 interacts with the peptidylarginine deiminase IV (PADI4). We demonstrate that PADI4 can act as an epigenetic coactivator through influencing H3R2me2a. At the Tal1/PADI4 target gene IL6ST the repressive H3R2me2a mark triggered by PRMT6 is counteracted by PADI4, which augments the active H3K4me3 mark and thus increases IL6ST expression. In contrast, at the CTCF promoter PADI4 acts as a repressor. We propose that the influence of PADI4 on IL6ST transcription plays a role in the control of IL6ST expression during lineage differentiation of hematopoietic stem/progenitor cells. These results open the possibility to pharmacologically influence Tal1 in leukaemia.

  3. Critical Roles of the LIM Domains of Lhx3 in Recruiting Coactivators to the Motor Neuron-Specifying Isl1-Lhx3 Complex.

    PubMed

    Seo, So Yeon; Lee, Bora; Lee, Seunghee

    2015-10-01

    During spinal cord development, the LIM domains of the LIM homeodomain factor Lhx3 bind to either the LIM cofactor nuclear LIM interactor (NLI) or another LIM homeodomain factor, Isl1, assembling the tetrameric V2 interneuron-specifying Lhx3 complex (2NLI:2Lhx3) or the hexameric motor neuron-specifying Isl1-Lhx3 complex (2NLI:2Isl1:2Lhx3). However, the detailed molecular basis by which the Lhx3-LIM domains contribute to motor neuron specification still remains poorly understood. Here, we show that the Lhx3-LIM domains are essential for recruiting transcriptional coactivators to the Isl1-Lhx3 complex. Using a yeast genetic screening system, we identify Lhx3 point mutants that bind to NLI but not Isl1. Accordingly, these mutants fail to assemble the Isl1-Lhx3 complex. However, their interaction with coactivators is relatively intact, and they are fully functional in the Lhx3 complex and V2 interneuron specification. Interestingly, when these Lhx3 mutants are directly fused to Isl1, their transcriptional activity in the Isl1-Lhx3 complex is restored. We further show that this restoration reflects an unexpected role of the Lhx3-LIM domains, likely together with Isl1, to form an interaction interface for coactivators. Our results suggest that the Lhx3-LIM domains play critical roles in transactivation of the Isl1-Lhx3 complex by not only directing the assembly of the Isl1-Lhx3 complex but also recruiting coactivators to the complex. PMID:26260513

  4. Critical Roles of the LIM Domains of Lhx3 in Recruiting Coactivators to the Motor Neuron-Specifying Isl1-Lhx3 Complex

    PubMed Central

    Seo, So Yeon; Lee, Bora

    2015-01-01

    During spinal cord development, the LIM domains of the LIM homeodomain factor Lhx3 bind to either the LIM cofactor nuclear LIM interactor (NLI) or another LIM homeodomain factor, Isl1, assembling the tetrameric V2 interneuron-specifying Lhx3 complex (2NLI:2Lhx3) or the hexameric motor neuron-specifying Isl1-Lhx3 complex (2NLI:2Isl1:2Lhx3). However, the detailed molecular basis by which the Lhx3-LIM domains contribute to motor neuron specification still remains poorly understood. Here, we show that the Lhx3-LIM domains are essential for recruiting transcriptional coactivators to the Isl1-Lhx3 complex. Using a yeast genetic screening system, we identify Lhx3 point mutants that bind to NLI but not Isl1. Accordingly, these mutants fail to assemble the Isl1-Lhx3 complex. However, their interaction with coactivators is relatively intact, and they are fully functional in the Lhx3 complex and V2 interneuron specification. Interestingly, when these Lhx3 mutants are directly fused to Isl1, their transcriptional activity in the Isl1-Lhx3 complex is restored. We further show that this restoration reflects an unexpected role of the Lhx3-LIM domains, likely together with Isl1, to form an interaction interface for coactivators. Our results suggest that the Lhx3-LIM domains play critical roles in transactivation of the Isl1-Lhx3 complex by not only directing the assembly of the Isl1-Lhx3 complex but also recruiting coactivators to the complex. PMID:26260513

  5. Co-activation: its association with weakness and specific neurological pathology

    PubMed Central

    Busse, Monica E; Wiles, Charles M; van Deursen, Robert WM

    2006-01-01

    Background Net agonist muscle strength is in part determined by the degree of antagonist co-activation. The level of co-activation might vary in different neurological disorders causing weakness or might vary with agonist strength. Aim This study investigated whether antagonist co-activation changed a) with the degree of muscle weakness and b) with the nature of the neurological lesion causing weakness. Methods Measures of isometric quadriceps and hamstrings strength were obtained. Antagonist (hamstring) co-activation during knee extension was calculated as a ratio of hamstrings over quadriceps activity both during an isometric and during a functional sit to stand (STS) task (using kinematics) in groups of patients with extrapyramidal (n = 15), upper motor neuron (UMN) (n = 12), lower motor neuron (LMN) with (n = 18) or without (n = 12) sensory loss, primary muscle or neuromuscular junction disorder (n = 17) and in healthy matched controls (n = 32). Independent t-tests or Mann Witney U tests were used to compare between the groups. Correlations between variables were also investigated. Results In healthy subjects mean (SD) co-activation of hamstrings during isometric knee extension was 11.8 (6.2)% and during STS was 20.5 (12.9)%. In patients, co-activation ranged from 7 to 17% during isometric knee extension and 15 to 25% during STS. Only the extrapyramidal group had lower co-activation levels than healthy matched controls (p < 0.05). Agonist isometric muscle strength and co-activation correlated only in muscle disease (r = -0.6, p < 0.05) and during STS in UMN disorders (r = -0.7, p < 0.5). Conclusion It is concluded that antagonist co-activation does not systematically vary with the site of neurological pathology when compared to healthy matched controls or, in most patient groups, with strength. The lower co-activation levels found in the extrapyramidal group require confirmation and further investigation. Co-activation may be relevant to individuals with muscle

  6. Structural development of stapled short helical peptides as vitamin D receptor (VDR)-coactivator interaction inhibitors.

    PubMed

    Misawa, Takashi; Demizu, Yosuke; Kawamura, Megumi; Yamagata, Nanako; Kurihara, Masaaki

    2015-03-01

    We developed several stabilized helical heptapeptides (DPI-01-10) composed of l-leucine residues, an α,α-disubstituted α-amino acid (α-aminoisobutyric acid [Aib] or hydroxymethylserine [Hms]), and a stapled side chain as inhibitors of vitamin D receptor (VDR)-coactivator interactions. The inhibitory activity of these peptides against VDR-coactivator interactions was evaluated using a receptor cofactor assay system, and DPI-08 demonstrated strong activity (IC50: 3.2μM). PMID:25637122

  7. Comparison of humeral rotation co-activation of breast cancer population and healthy shoulders.

    PubMed

    Brookham, Rebecca L; Dickerson, Clark R

    2016-08-01

    Upper limb morbidities are common amongst the breast cancer population (BCP) and have a direct impact on independence. Comparing muscle co-activation strategies between BCP and healthy populations may assist in identifying muscle dysfunction and promote clinical interpretation of dysfunction, which could direct preventative and therapeutic interventions. The purposes of this study were to define humeral rotation muscle co-activation of a BCP and to compare it with a previously defined co-activation relationship of a healthy population. Fifty BCP survivors performed 18 isometric internal and external rotation exertions at various postures and intensities. Surface and intramuscular electrodes recorded shoulder muscle activity. BCP co-activation was predicted at r(2)=0.77 during both exertion types. Humeral abduction angle and task intensity were important factors in the prediction of co-activation in both populations. Comparisons made between populations identified differing muscle strategies used by BCP to maintain postural control. Compared to healthy co-activation, the BCP demonstrated greater activation of internal (IR) and external rotator (ER) type muscles during their respective rotation type. The BCP demonstrated increased (⩾8.7%) activation of pectoralis major. This study has provided insight into how BCP muscles compensate during dysfunction. Continued advancement of this knowledge can provide more understanding of dysfunction, promote generation of evidence-based therapies, and can be useful in biomechanical modeling. PMID:26296634

  8. Coactivation of Gustatory and Olfactory Signals in Flavor Perception

    PubMed Central

    Veldhuizen, Maria G.; Shepard, Timothy G.; Wang, Miao-Fen

    2010-01-01

    It is easier to detect mixtures of gustatory and olfactory flavorants than to detect either component alone. But does the detection of mixtures exceed the level predicted by probability summation, assuming independent detection of each component? To answer this question, we measured simple response times (RTs) to detect brief pulses of one of 3 flavorants (sucrose [gustatory], citral [olfactory], sucrose–citral mixture) or water, presented into the mouth by a computer-operated, automated flow system. Subjects were instructed to press a button as soon as they detected any of the 3 nonwater stimuli. Responses to the mixtures were faster (RTs smaller) than predicted by a model of probability summation of independently detected signals, suggesting positive coactivation (integration) of gustation and retronasal olfaction in flavor perception. Evidence for integration appeared mainly in the fastest 60% of the responses, indicating that integration arises relatively early in flavor processing. Results were similar when the 3 possible flavorants, and water, were interleaved within the same session (experimental condition), and when each flavorant was interleaved with water only (control conditions). This outcome suggests that subjects did not attend selectively to one flavor component or the other in the experimental condition and further supports the conclusion that (late) decisional or attentional strategies do not exert a large influence on the gustatory–olfactory flavor integration. PMID:20032112

  9. The transcriptional coactivator and acetyltransferase p300 in fibroblast biology and fibrosis.

    PubMed

    Ghosh, Asish K; Varga, John

    2007-12-01

    The transcriptional coactivator p300 is a ubiquitous nuclear phosphoprotein and transcriptional cofactor with intrinsic acetyltransferase activity. p300 controls the expression of numerous genes in cell-type and signal-specific manner, and plays a pivotal role in cellular proliferation, apoptosis, and embryogenesis. By catalyzing acetylation of histones and transcription factors, p300 plays a significant role in epigenetic regulation. Recent evidence suggests that abnormal p300 function is associated with deregulated target gene expression, and is implicated in inflammation, cancer, cardiac hypertrophy, and genetic disorders such as the Rubinstein-Taybi syndrome. The activity of p300 is regulated at multiple levels, including developmental stage-specific expression, post-translational modifications, subcellular localization, and cell-type and gene-specific interactions with transcription factors. Although p300 has been investigated extensively in epithelial and hematopoietic cells, its role in fibroblast biology and tissue repair has received little attention to date. Recent studies implicate p300 in the regulation of collagen synthesis by transforming growth factor-beta (TGF-beta). Both the acetyltransferase activity of p300 and its inducible interaction with Smad3 are essential for mediating TGF-beta-induced stimulation of collagen synthesis. As a signal integrator whose availability for intracellular interactions with transcription factors is strictly limiting, p300 mediates the antagonistic regulation of TGF-beta-induced collagen synthesis by IFN-gamma and TNF-alpha via intracellular competition for limiting amount of p300. Significantly, p300 is itself a direct transcriptional target of TGF-beta in normal fibroblasts, and its levels are significantly elevated in fibrotic lesions as well as in experimental models of fibrosis. The emerging appreciation of the importance of p300 in extracellular matrix (ECM) remodeling and fibrosis and novel insights concerning

  10. Androgen Receptor Coactivators in Regulation of Growth and Differentiation in Prostate Cancer.

    PubMed

    Culig, Zoran

    2016-02-01

    Androgen receptor (AR) is a key factor in regulation of growth and differentiation in normal and malignant prostate. Endocrine therapies for prostate cancer include inhibition of androgen production either by analogs of luteinizing hormone releasing hormone or abiraterone acetate and/or use of anti-androgens such as hydroxyflutamide, bicalutamide, and enzalutamide. Castration therapy-resistant cancer develops inevitably in patients who undergo treatment. AR coactivators are proteins which interact with one or more regions of the AR thus enhancing its function. Although several functions of AR coactivators may be redundant, specific functions have been identified and analyzed. The p160 group of coactivators, SRC-1, -2, and -3 not only potentiate the activation of the AR, but are also implicated in potentiation of function of insulin-like growth factor-I and activation of the Akt pathway. Transcriptional integrators p300 and CBP are up-regulated by androgen ablation and may influence antagonist/agonist balance of non-steroidal anti-androgens. A therapy approach designed to target p300 in prostate cancer revealed its role in regulation of proliferation of migration of androgen-sensitive and -insensitive prostate cancer cells. Coactivators p300 and SRC-1 are required for AR activation by interleukin-6 (IL-6), a cytokine that is overexpressed in castration therapy-resistant prostate cancer. Some coactivators, such as Vav3, are involved in regulation of transcriptional activity of truncated AR, which emerge during endocrine thrapy. Stimulation of cellular migration and invasion by AR coactivators has also been described. Translational studies with aim to introduce anti-AR coactivator therapy have not been successfully implemented in the clinic so far. PMID:26201947

  11. Developing through relationships: an embodied coactive systems framework.

    PubMed

    Mascolo, Michael F

    2013-01-01

    In recent decades, the developmental sciences have undergone a relational turn. Epigenetic (Gottlieb & Lickliter, 2007), embodied (Thompson, 2007), relational (Lerner & Overton, 2008) and systems (Kelso, 2003) approaches are transforming the ways in which we think about the nature and origins of psychological structures. At their most basic level, relational and systems approaches analyze the developmental origins of order and variability not in terms of sets of separable causal forces but instead in analyses of relations between causal systems. From this view, genes and environment, biology and culture, cognition and emotion, self and other, and so forth are inseparable as causal processes in the development of action and experience. Drawing on these principles, this paper contains an outline of an embodied coactive systems framework for understanding how individual psychological structures develop as a product of socially distributed coactions that occur among elements of the extended person-environment system. Based on these principles, a system for the Developmental Analysis of Joint Action is described. This system provides a set of conceptual and empirical tools for making precise assessments of dynamic structure of jointly constructed patterns of thinking, feeling and acting. By tracking developmental changes in joint action, the system allows researchers to track the origins of higher order psychological structures through particular sequences of coconstructive activity. The holistic analytic system is illustrated through microdevelopmental analyses of (1) the joint construction of shoe-tying skill between a 5-year-old boy and a caregiver, and (2) socioemotional organization developing representations of self in a young adult over the course of a single session of psychotherapy. PMID:23865117

  12. Identification of SRC3/AIB1 as a Preferred Coactivator for Hormone-activated Androgen Receptor

    SciTech Connect

    Zhou, X. Edward; Suino-Powell, Kelly M.; Li, Jun; He, Yuanzheng; MacKeigan, Jeffrey P.; Melcher, Karsten; Yong, Eu-Leong; Xu, H.Eric

    2010-09-17

    Transcription activation by androgen receptor (AR), which depends on recruitment of coactivators, is required for the initiation and progression of prostate cancer, yet the mechanisms of how hormone-activated AR interacts with coactivators remain unclear. This is because AR, unlike any other nuclear receptor, prefers its own N-terminal FXXLF motif to the canonical LXXLL motifs of coactivators. Through biochemical and crystallographic studies, we identify that steroid receptor coactivator-3 (SRC3) (also named as amplified in breast cancer-1 or AIB1) interacts strongly with AR via synergistic binding of its first and third LXXLL motifs. Mutagenesis and functional studies confirm that SRC3 is a preferred coactivator for hormone-activated AR. Importantly, AR mutations found in prostate cancer patients correlate with their binding potency to SRC3, corroborating with the emerging role of SRC3 as a prostate cancer oncogene. These results provide a molecular mechanism for the selective utilization of SRC3 by hormone-activated AR, and they link the functional relationship between AR and SRC3 to the development and growth of prostate cancer.

  13. Nuclear localization of coactivator RAC3 is mediated by a bipartite NLS and importin {alpha}3

    SciTech Connect

    Yeung, Percy Luk; Zhang, Aihua; Chen, J. Don . E-mail: chenjd@umdnj.edu

    2006-09-15

    The nuclear receptor coactivator RAC3 (also known as SRC-3/ACTR/AIB1/p/CIP/TRAM-1) belongs to the p160 coactivator family, which are involved in several physiological processes and diseases. Here we have investigated how RAC3 is translocated into the nucleus and show that it is mediated through a bipartite NLS and importin {alpha}3. This bipartite NLS is located within the conserved bHLH domain, and its mutation abolished nuclear localization. The NLS is also sufficient to cause nuclear import of EGFP, and the activity requires basic amino acids within the NLS. RAC3 binds strongly to importin {alpha}3, which also depends on the basic amino acids. Functionally, RAC3 cytoplasmic mutant loses its ability to enhance transcription, suggesting that nuclear localization is essential for coactivator function. Together, these results reveal a previous unknown mechanism for nuclear translocation of p160 coactivators and a critical function of the conserved bHLH within the coactivator.

  14. BOB.1 of the channel catfish, Ictalurus punctatus: Not a transcriptional coactivator?

    PubMed Central

    Richard, Mara L. Lennard; Hikima, Jun-ichi; Wilson, Melanie R.; Miller, Norman W.; Cunningham, Charles; Warr, Gregory W.

    2010-01-01

    Expression of the immunoglobulin heavy chain (IGH) locus of the channel catfish (Ictalurus punctatus)is driven by the Eμ3′ enhancer, whose core region contains two octamer motifs and a μE5 site. Orthologues of the Oct1 and Oct2 transcription factors have been cloned in the channel catfish and shown to bind to the octamer motifs within the core enhancer. While catfish Oct2 is an activator of transcription, catfish Oct1 failed to drive transcription and may act as a negative regulator of IGH transcription. In mammals, the Oct co-activator BOB.1 (B cell Oct-binding protein1, also known as OCA-B and OBF-1) greatly enhances the transcriptional activity of Oct factors and plays an important role in the development of the immune system. An orthologue of BOB.1 has been cloned in the catfish, and its function characterized. The POU binding domain of the catfish BOB.1 was found to be 95% identical at the amino acid level with the binding domain of human BOB.1, and all the residues directly involved in binding to the Oct-DNA complex were conserved. Despite this conservation, catfish BOB.1 failed to enhance transcriptional activation mediated by endogenous or co-transfected catfish Oct2, and failed to rescue the activity of the inactive catfish Oct1. Electrophoretic mobility shift assays showed that catfish BOB.1 was capable of binding both catfish Oct1 and Oct2 when they formed a complex with the Oct motif. Analysis of recombinant chimeric catfish and human BOB.1 proteins demonstrated that the failure to drive transcription was due to the lack of a functional activation domain within the catfish BOB.1. PMID:19041136

  15. Research Resource: Loss of the Steroid Receptor Coactivators Confers Neurobehavioral Consequences

    PubMed Central

    Stashi, Erin; Wang, Lei; Mani, Shailaja K.; York, Brian

    2013-01-01

    Steroid receptor coactivators (SRCs) are important transcriptional modulators that regulate nuclear receptor and transcription factor activity to adjust transcriptional output to cellular demands. Highlighting their pleiotropic effects, dysfunction of the SRCs has been found in numerous pathologies including cancer, inflammation, and metabolic disorders. The SRC family is expressed strongly in the brain including the hippocampus, cortex, and hypothalamus. Studies focusing on the effect of SRC loss using congenic SRC knockout mice (SRC−/−) are limited in number, yet strongly indicate that the SRCs play important roles in regulating reproductive behavior, development, and motor coordination. To better understand the unique functions of the SRCs, we performed a neurobehavioral test battery focusing on anxiety and exploratory behaviors, motor coordination, sensorimotor gating, and nociception in both male and female null mice and compared them with their wild-type (WT) littermates. Results from the test battery reveal a role for SRC1 in motor coordination. Additionally, we found that SRC1 regulates anxiety responses in SRC1−/− male and female mice, and nociception sensitivity in SRC1−/− male but not female mice. By comparison, SRC2 regulates anxiety response with SRC2−/− females showing decreased anxiety in novel environments, as well as increased exploratory behavior in the open field compared with WT littermates. Additionally, SRC2−/− males were shown to have deficits in sensorimotor gating. Loss of SRC3 also shows sex differences in anxiety and exploratory behaviors. In particular, SRC3−/− female mice have increased anxiety and reduced exploratory activity and impairments in prepulse inhibition, whereas SRC3−/− male mice show no significant behavioral differences. In both genders, ablation of SRC3 decreases nocifensive behaviors. Collectively, these resource data suggest that loss of the SRCs results in behavioral phenotypes, underscoring

  16. A dynamic model for PC4 coactivator function in RNA polymerase II transcription

    PubMed Central

    Malik, Sohail; Guermah, Mohamed; Roeder, Robert G.

    1998-01-01

    Human positive cofactor (PC4) acts as a general coactivator for activator-dependent transcription by RNA polymerase II. Here we show that PC4 coactivator function, in contrast to basal (activator-independent) transcription, is dependent both on TATA binding protein (TBP)-associated factors (TAFs) in TFIID and on TFIIH. Surprisingly, PC4 strongly represses transcription initiation by minimal preinitiation complexes in the absence of TAFs and TFIIH, while simultaneously promoting the formation of these complexes. Furthermore, TFIIH and TAFII250, the largest subunit of TFIID, can both phosphorylate PC4. These results provide evidence for an inactive, PC4-induced intermediate in preinitiation complex assembly and point to TFIIH and TAF requirements for its progression into a functional preinitiation complex. Thus PC4 coactivator activity is realized in a stepwise series of events reminiscent of prokaryotic activation pathways involving conversion of inactive RNA polymerase-promoter complexes to an initiation-competent state. PMID:9482861

  17. Modulation of steroid action in the central and peripheral nervous systems by nuclear receptor coactivators

    PubMed Central

    Tetel, Marc J.

    2009-01-01

    Steroid hormones act in the central and peripheral nervous systems to regulate a variety of functions, including development, cell proliferation, cognition and behavior. Many of these effects of steroid hormones are mediated by their respective receptors, which are members of the nuclear receptor superfamily of transcriptional activators. A variety of cell culture studies reveal that nuclear receptor coactivators are recruited to the steroid receptor complex and are critical in modulating steroid-dependent transcription. Thus, in addition to the availability of the hormone and its receptor, the expression of nuclear receptor coactivators is essential for modulating steroid receptor mediated transcription. This review will discuss the significance of nuclear receptor coactivators in modulating steroid-dependent gene expression in the central and peripheral nervous systems and the regulation of behavior. PMID:19541426

  18. Nuclear Receptor Coactivators Are Coexpressed with Steroid Receptors and Regulated by Estradiol in Mouse Brain

    PubMed Central

    Tognoni, Christina M.; Chadwick, Joseph G.; Ackeifi, Courtney A.; Tetel, Marc J.

    2011-01-01

    Background/Aims The steroid hormones, including estradiol (E) and progesterone, act in the brain to regulate female reproductive behavior and physiology. These hormones mediate many of their biological effects by binding to their respective intracellular receptors. The receptors for estrogens (ER) and progestins (PR) interact with nuclear receptor coactivators to initiate transcription of steroid-responsive genes. Work from our laboratory and others reveals that nuclear receptor coactivators, including steroid receptor coactivator-1 (SRC-1) and SRC-2, function in brain to modulate ER-mediated induction of the PR gene and hormone-dependent behaviors. In order for steroid receptors and coactivators to function together, both must be expressed in the same cells. Methods Triple-label immunofluorescence was used to determine if E-induced PR cells also express SRC-1 or SRC-2 in reproductively relevant brain regions of the female mouse. Results The majority of E-induced PR cells in the medial preoptic area (61%), ventromedial nucleus of the hypothalamus (63%) and arcuate nucleus (76%) coexpressed both SRC-1 and SRC-2. A smaller proportion of PR cells expressed either SRC-1 or SRC-2, while a few PR cells expressed neither coactivator. In addition, compared to control animals, 17β-estradiol benzoate (EB) treatment increased SRC-1 levels in the arcuate nucleus, but not the medial preoptic area or the ventromedial nucleus of the hypothalamus. EB did not alter SRC-2 expression in any of the three brain regions analyzed. Conclusions Taken together, the present findings identify a population of cells in which steroid receptors and nuclear receptor coactivators may interact to modulate steroid sensitivity in brain and regulate hormone-dependent behaviors in female mice. Given that cell culture studies reveal that SRC-1 and SRC-2 can mediate distinct steroid-signaling pathways, the present findings suggest that steroids can produce a variety of complex responses in these

  19. Expression and significance of androgen receptor coactivators in urothelial carcinoma of the bladder.

    PubMed

    Boorjian, Stephen A; Heemers, Hannelore V; Frank, Igor; Farmer, Sara A; Schmidt, Lucy J; Sebo, Thomas J; Tindall, Donald J

    2009-03-01

    Urothelial carcinoma (UC) of the bladder is approximately three times more common in men than women. While the etiology for this gender difference in incidence remains unknown, a role for androgen receptor (AR) signaling has been suggested. The mechanisms by which AR activity is regulated in UC cells, however, are largely elusive. Here, we explore the significance of coregulators that are critical for the formation of a functional AR transcriptional complex, in UC cells. Using two AR-positive UC cell lines, TCC-SUP and UMUC3, we demonstrate the expression of the coactivators NCOA1, NCOA2, NCOA3, CREBBP, and EP300 in UC cells. small interfering RNA-mediated knockdown of the AR or any of these coactivators markedly impacted cell viability and abrogated androgen-dependent cell proliferation. Noteworthy, contrary to AR-positive prostate cancer cells, expression of these AR-associated coactivators was not androgen regulated in UC cells. To assess the clinical relevance of coactivator expression, we performed immunohistochemistry on paraffin-embedded sections from 55 patients with UC of the bladder. We found that while 24 out of 55 (44%) of tumors expressed the AR, each of the coactivators was expressed by 85-100% of the bladder cancers. Moreover, we noted a significant downregulation of NCOA1 expression in tumors versus adjacent, non-tumor bladder urothelium, with a mean of 68% (range 0-100) of tumor cells demonstrating NCOA1 staining versus a mean of 81% (range 0-90) of non-tumor cells (P=0.03). Taken together, our data suggest an important role for AR-associated coactivators in UC and point toward differences in the regulation of AR activity between bladder and prostate cancer cells. PMID:18845648

  20. Coaching younger practitioners and students using components of the co-active coaching model.

    PubMed

    Tofade, Toyin

    2010-04-12

    Coaching is used to improve performance, achieve preset goals and obtain desired results. Several coaching models have been used in health professions for leadership and professional development. This article describes some components of Co-Active Coaching(R) that can be applied while coaching pharmacy students and younger practitioners. Co-Active Coaching requires the coach to use a broad range of communication skills, including listening, asking powerful questions, making insightful comments, offering encouragement, and giving sincere praise. The characteristics of the ideal candidate for coaching and the value of coaching are also discussed. PMID:20498744

  1. The Structure of A Biologically Active Estrogen Receptor-Coactivator Complex on DNA

    PubMed Central

    Yi, Ping; Wang, Zhao; Feng, Qin; Pintilie, Grigore D.; Foulds, Charles E.; Lanz, Rainer B.; Ludtke, Steven J.; Schmid, Michael F.; Chiu, Wah; O’Malley, Bert W.

    2015-01-01

    SUMMARY Estrogen receptor (ER) is a transcription factor critical for development, reproduction, metabolism and cancer. ER function hinges on its ability to recruit primary and secondary coactivators, yet structural information on the full-length receptor-coactivator complex to complement pre-existing and sometimes controversial biochemical information is lacking. Here we use cryo-EM to determine the quaternary structure of an active complex of DNA-bound ERα, steroid receptor coactivator 3 (SRC-3) and a secondary coactivator (p300). Our structural model suggests the following assembly mechanism for the complex: each of the two ligand-bound ERα monomers independently recruits one SRC-3 protein via the transactivation domain of ERα; the two SRC-3s in turn bind to different regions of one p300 protein through multiple contacts. We also present structural evidence for the location of activation function 1 (AF-1) in a full-length nuclear receptor, which supports a role for AF-1 in SRC-3 recruitment. PMID:25728767

  2. The Race that Precedes Coactivation: Development of Multisensory Facilitation in Children

    ERIC Educational Resources Information Center

    Barutchu, Ayla; Crewther, David P.; Crewther, Sheila G.

    2009-01-01

    Rationale: The facilitating effect of multisensory integration on motor responses in adults is much larger than predicted by race-models and is in accordance with the idea of coactivation. However, the development of multisensory facilitation of endogenously driven motor processes and its relationship to the development of complex cognitive skills…

  3. Ubiquitination of RORγt at Lysine 446 Limits Th17 Differentiation by Controlling Coactivator Recruitment.

    PubMed

    He, Zhiheng; Wang, Fei; Ma, Jian; Sen, Subha; Zhang, Jing; Gwack, Yousang; Zhou, Yu; Sun, Zuoming

    2016-08-15

    The transcription factor retinoid acid-related orphan receptor γ t (RORγt) directs the differentiation of Th17 cells. Th17 cells mediate pathological immune responses responsible for autoimmune diseases, including psoriasis and multiple sclerosis. Previous studies focused on RORγt target genes and their function in Th17 differentiation. In this study, we assessed posttranscriptional regulation of RORγt and identified a functional ubiquitination site, K446. Mutation of K446 to arginine to prevent ubiquitination greatly enhanced recruitment of steroid receptor coactivator 1 (SRC1), a coactivator critical for RORγt activity. Correspondingly, the K446 to arginine mutation potentiated Th17 differentiation. We also showed that ubiquitin-specific protease (USP)15 interacted with RORγt, removed ubiquitin from K446, and stimulated RORγt activity by enhancing coactivator SRC1 recruitment. Knockdown of USP15 or expression of inactive USP15 impaired Th17 differentiation, suggesting a positive role for USP15-mediated deubiquitination of RORγt in Th17 differentiation. Therefore, ubiquitination of K446 limits RORγt-mediated Th17 differentiation by inhibiting the recruitment of coactivator SRC1. Our study will inform the development of treatments that target RORγt ubiquitination pathways to limit Th17-mediated autoimmunity. PMID:27430721

  4. SRC-2 is an essential coactivator for orchastrating metabolism and circadian rhythm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Synchrony of the mammalian circadian clock is achieved by complex transcriptional and translational feedback loops centered on the BMAL1:CLOCK heterodimer. Modulation of circadian feedback loops is essential for maintaining rhythmicity, yet the role of transcriptional coactivators in driving BMAL1:C...

  5. Modulation of PGC-1 coactivator pathways in brown fat differentiation through LRP130.

    PubMed

    Cooper, Marcus P; Uldry, Marc; Kajimura, Shingo; Arany, Zoltan; Spiegelman, Bruce M

    2008-11-14

    The PGC-1 coactivators are important regulators of oxidative metabolism. We previously demonstrated that LRP130 is a binding partner of PGC-1alpha, required for hepatic gluconeogenesis. LRP130 is the gene mutated in Leigh syndrome French Canadian variant, a rare neurodegenerative disease. The importance of LRP130 in other, non-hepatocyte biology remains obscure. To better understand PGC-1 coactivator function in brown fat development, we explored the metabolic role of LRP130 in brown adipocyte differentiation. We show that LRP130 is preferentially enriched in brown fat compared with white, and induced in a PGC-1-dependent manner during differentiation. Despite intact PGC-1 coactivator expression, brown fat cells deficient for LRP130 exhibit attenuated expression of several genes characteristic of brown fat, including uncoupling protein 1. Oxygen consumption studies support a specific defect in proton leak due to attenuated uncoupling protein 1 expression. Notably, brown fat cell development common to both PGC-1 coactivators is governed by LRP130. Conversely, the cAMP response controlled by PGC-1alpha is not regulated by LRP130. These data implicate LRP130 in brown fat cell development and differentiation. PMID:18728005

  6. Effects of Response Task and Accessory Stimuli on Redundancy Gain: Tests of the Hemispheric Coactivation Model

    ERIC Educational Resources Information Center

    Miller, Jeff; Van Nes, Fenna

    2007-01-01

    Two experiments tested predictions of the hemispheric coactivation model for redundancy gain (J. O. Miller, 2004). Simple reaction time was measured in divided attention tasks with visual stimuli presented to the left or right of fixation or redundantly to both sides. Experiment 1 tested the prediction that redundancy gain--the decrease in…

  7. Regulated recruitment of tumor suppressor BRCA1 to the p21 gene by coactivator methylation

    PubMed Central

    Lee, Young-Ho; Bedford, Mark T.; Stallcup, Michael R.

    2011-01-01

    Tumor suppression by p53 and BRCA1 involves regulation of cell cycle, apoptosis, and DNA repair and is influenced by transcriptional coactivators and post-translational modifications. Here we show that coactivator-associated arginine methyltransferase 1 (CARM1) methylates Arg 754 in the KIX region of coactivator p300. Methylated p300 and p300 protein fragments are preferentially recognized by BRCT domains of BRCA1, identifying the BRCT domain as a novel methylarginine-binding module. CARM1 and p300 cooperate with BRCA1 and p53 to induce expression of the critical cell cycle and proliferation regulator p21WAF1/CIP1 in response to DNA damage. This induction was severely attenuated by elimination of CARM1 or its methyltransferase activity, or by mutation of Arg 754 of p300. Absence of CARM1 methyltransferase activity led to failure of cells to arrest in the G1 phase of the cell cycle in response to DNA damage. CARM1 methyltransferase activity was required for induction of some p53 target genes (p21 and Gadd45) but not others (Bax) by DNA damage. Recruitment of BRCA1 to the p53-binding region of the p21 promoter in response to DNA damage required methylation of Arg 754 of p300 by CARM1. Thus, coactivator methylation may be crucial for fine-tuning the tumor suppressor function of BRCA1 and other BRCT domain proteins. PMID:21245169

  8. A muscle-specific knockout implicates nuclear receptor coactivator MED1 in the regulation of glucose and energy metabolism

    PubMed Central

    Chen, Wei; Zhang, Xiaoting; Birsoy, Kivanc; Roeder, Robert G.

    2010-01-01

    As conventional transcriptional factors that are activated in diverse signaling pathways, nuclear receptors play important roles in many physiological processes that include energy homeostasis. The MED1 subunit of the Mediator coactivator complex plays a broad role in nuclear receptor-mediated transcription by anchoring the Mediator complex to diverse promoter-bound nuclear receptors. Given the significant role of skeletal muscle, in part through the action of nuclear receptors, in glucose and fatty acid metabolism, we generated skeletal muscle-specific Med1 knockout mice. Importantly, these mice show enhanced insulin sensitivity and improved glucose tolerance as well as resistance to high-fat diet–induced obesity. Furthermore, the white muscle of these mice exhibits increased mitochondrial density and expression of genes specific to type I and type IIA fibers, indicating a fast-to-slow fiber switch, as well as markedly increased expression of the brown adipose tissue-specific UCP-1 and Cidea genes that are involved in respiratory uncoupling. These dramatic results implicate MED1 as a powerful suppressor in skeletal muscle of genetic programs implicated in energy expenditure and raise the significant possibility of therapeutical approaches for metabolic syndromes and muscle diseases through modulation of MED1–nuclear receptor interactions. PMID:20479251

  9. Potential role of 8-oxoguanine DNA glycosylase 1 as a STAT1 coactivator in endotoxin-induced inflammatory response.

    PubMed

    Kim, Hong Sook; Kim, Byung-Hak; Jung, Joo Eun; Lee, Chang Seok; Lee, Hyun Gyu; Lee, Jung Weon; Lee, Kun Ho; You, Ho Jin; Chung, Myung-Hee; Ye, Sang-Kyu

    2016-04-01

    Human 8-oxoguanine DNA glycosylase 1 (OGG1) is the major DNA repair enzyme that plays a key role in excision of oxidative damaged DNA bases such as 8-oxoguainine (8-oxoG). Recent studies suggest another function of OGG1, namely that it may be involved in the endotoxin- or oxidative stress-induced inflammatory response. In this study, we investigated the role of OGG1 in the inflammatory response. OGG1 expression is increased in the organs of endotoxin-induced or myelin oligodendrocyte glycoprotein (MOG)-immunized mice and immune cells, resulting in induction of the expression of pro-inflammatory mediators at the transcriptional levels. Biochemical studies showed that signal transducer and activator of transcription 1 (STAT1) plays a key role in endotoxin-induced OGG1 expression and inflammatory response. STAT1 regulates the transcriptional activity of OGG1 through recruiting and binding to the gamma-interferon activation site (GAS) motif of the OGG1 promoter region, and chromatin remodeling by acetylation and dimethylation of lysine-14 and -4 residues of histone H3. In addition, OGG1 acts as a STAT1 coactivator and has transcriptional activity in the presence of endotoxin. The data presented here identifies a novel mechanism, and may provide new therapeutic strategies for the treatment of endotoxin-mediated inflammatory diseases. PMID:26496208

  10. Ligand-dependent interactions of the Ah receptor with coactivators in a mammalian two-hybrid assay

    SciTech Connect

    Zhang Shu; Rowlands, Craig; Safe, Stephen

    2008-03-01

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a high affinity ligand for the aryl hydrocarbon receptor (AhR). In this study, we investigated structure-dependent differences in activation of the AhR by a series of halogenated aromatic hydrocarbons. TCDD, 1,2,3,7,8-pentachlorodibenzo-p-dioxin (PeCDD), 2,3,7,8-tetrachlorodibenzofuran (TCDF), 2,3,4,7,8-pentachlorodibenzofuran (PeCDF), and 3,3',4,4',5-pentachlorobiphenyl (PCB126) induced CYP1A1-dependent activities in HEK293 human embryonic kidney, Panc1 pancreatic cancer, and Hepa1c1c7 mouse hepatoma cell lines. There was a structure-dependent difference in the efficacy of TCDF and PCB126 in HEK293 and Panc1 cells since induced CYP1A1 mRNA levels were lower than observed for the other congeners. A mammalian two-hybrid assay in cells transfected with GAL4-coactivator and AhR-VP16 chimeras was used to investigate structure-dependent interactions of these chimeras in Panc1, HEK293, and Hepa1c1c7 cells. The reporter construct pGAL4-luc contains five tandem GAL4 response elements linked to the luciferase gene and the GAL4-coactivator chimeras express several coactivators including steroid receptor coactivator 1 (SRC-1), SRC-2 and SRC-3, the mediator coactivator TRAP220, coactivator associated arginine methyl transferase 1 (CARM-1), and peroxisome proliferator-activated receptor {gamma} coactivator 1 (PGC-1). Results of the mammalian two-hybrid studies clearly demonstrate that activation of pGAL4-luc in cells transfected with VP-AhR and GAL4-coactivator chimeras is dependent on the structure of the HAH congener, cell context, and coactivator, suggesting that the prototypical HAH congeners used in this study exhibit selective AhR modulator activity.

  11. Quantification of silkworm coactivator of MBF1 mRNA by SYBR Green I real-time RT-PCR reveals tissue- and stage-specific transcription levels.

    PubMed

    Li, Guang-li; Roy, Bhaskar; Li, Xing-hua; Yue, Wan-fu; Wu, Xiao-feng; Liu, Jian-mei; Zhang, Chuan-xi; Miao, Yun-gen

    2009-05-01

    Transcriptional coactivators play a crucial role in gene transcription and expression. Multiprotein bridging factor 1 (MBF1) is a transcriptional coactivator necessary for transcriptional activation caused by DNA-binding activators, such as FTZ-F1 and GCN4. Until now, very few studies have been reported in the silkworm. We selected the Bombyx mori because it is a model insect and acts as an economic animal for silk industry. In this study, we conducted the quantitative analysis of MBF1 mRNA in silkworm B. mori L. with actin (A3) as internal standard by means of SYBR Green I real-time RT-PCR method. The total RNA was extracted from the silk gland, epidermis, fat body, and midguts of the fifth instar B. mori larvae. The mRNA was reverse transcripted, and the cDNA fragments of MBF1 mRNA and actin gene were amplified by RT-PCR using specific primers. MBF1 mRNA expression in different tissues of silkworm B. mori L. was quantified using standardized SYBR Green I RT-PCR. The results suggested MBF1 gene was expressed in all investigated organs but highly expressed in the silk gland, showing its relation to biosynthesis of silk proteins. PMID:18612846

  12. Krüppel-like Factor 6 Is a Co-activator of NF-κB That Mediates p65-dependent Transcription of Selected Downstream Genes*

    PubMed Central

    Zhang, Yu; Lei, Cao-Qi; Hu, Yun-Hong; Xia, Tian; Li, Mi; Zhong, Bo; Shu, Hong-Bing

    2014-01-01

    The transcription factor NF-κB plays a pivotal role in a broad range of physiological and pathological processes, including development, inflammation, and immunity. How NF-κB integrates activating signals to expression of specific sets of target genes is of great interest. Here, we identified Krüppel-like factor 6 (KLF6) as a co-activator of NF-κB after TNFα and IL-1β stimulation. Overexpression of KLF6 enhanced TNFα- and IL-1β-induced activation of NF-κB and transcription of a subset of downstream genes, whereas knockdown of KLF6 had opposite effects. KLF6 interacted with p65 in the nucleus and bound to the promoters of target genes. Upon IL-1β stimulation, KLF6 was recruited to promoters of a subset of NF-κB target genes in a p65-dependent manner, which was in turn required for the optimal binding of p65 to the target gene promoters. Our findings thus identified KLF6 as a previously unknown but essential co-activator of NF-κB and provided new insight into the molecular regulation of p65-dependent gene expression. PMID:24634218

  13. Yeast Cyc8p and Tup1p proteins function as coactivators for transcription of Stp1/2p-dependent amino acid transporter genes.

    PubMed

    Tanaka, Naoko; Mukai, Yukio

    The yeast Cyc8p-Tup1p complex is known to serve primarily as a transcriptional corepressor in a variety of biological processes. However, less is known about its function as a coactivator. Herein, we found tryptophan transporter genes, TAT1 and TAT2, that, when overexpressed, suppressed the slow growth of Δcyc8. We observed that the addition of tryptophan to Δcyc8 cultures partially restored cell growth, and the deletion of CYC8 and TUP1 reduced transcriptional levels of TAT1 and TAT2. Tup1p bound to the promoter region of TAT1 and TAT2 genes that were dependent on STP1 and STP2 (encoding DNA-binding activator proteins) for expression. Similarly, transcription of the other Stp1/2p-dependent amino acid transporter (AAT) genes also required CYC8 and TUP1 gene functions. These data indicate that Cyc8p-Tup1p plays a role as a transcriptional coactivator for AAT genes via Stp1/2p activators and that lowering intracellular tryptophan by CYC8 deletion causes slow growth. PMID:26546823

  14. Neural co-activation as a yardstick of implicit motor learning and the propensity for conscious control of movement.

    PubMed

    Zhu, F F; Poolton, J M; Wilson, M R; Maxwell, J P; Masters, R S W

    2011-04-01

    Two studies examined EEG co-activation (coherence) between the verbal-analytical (T3) and motor planning (Fz) regions during a golf putting task. In Study 1, participants with a strong propensity to consciously monitor and control their movements, determined psychometrically by high scores on a movement specific Reinvestment Scale, displayed more alpha2 T3-Fz co-activation than participants with a weak propensity. In Study 2, participants who practiced a golf putting task implicitly (via an errorless learning protocol) displayed less alpha2 T3-Fz co-activation than those who practiced explicitly (by errorful learning). In addition, explicit but not implicit motor learners displayed more T3-Fz co-activation during golf putting under pressure, implying that verbal-analytical processing of putting movements increased under pressure. These findings provide neuropsychological evidence that supports claims that implicit motor learning can be used to limit movement specific reinvestment. PMID:21315795

  15. MiR130b-Regulation of PPARγ Coactivator- 1α Suppresses Fat Metabolism in Goat Mammary Epithelial Cells.

    PubMed

    Chen, Zhi; Luo, Jun; Ma, LiuAn; Wang, Hui; Cao, WenTing; Xu, HuiFei; Zhu, JiangJiang; Sun, YuTing; Li, Jun; Yao, DaWei; Kang, Kang; Gou, Deming

    2015-01-01

    Fat metabolism is a complicated process regulated by a series of factors. microRNAs (miRNAs) are a class of negative regulator of proteins and play crucial roles in many biological processes; including fat metabolism. Although there have been some researches indicating that miRNAs could influence the milk fat metabolism through targeting some factors, little is known about the effect of miRNAs on goat milk fat metabolism. Here we utilized an improved miRNA detection assay, S-Poly-(T), to profile the expression of miRNAs in the goat mammary gland in different periods, and found that miR-130b was abundantly and differentially expressed in goat mammary gland. Additionally, overexpressing miR-130b impaired adipogenesis while inhibiting miR-130b enhanced adipogenesis in goat mammary epithelial cells. Utilizing 3'-UTR assay and Western Blot analusis, the protein peroxisome proliferator-activated receptor coactivator-1α (PGC1α), a major regulator of fat metabolism, was demonstrated to be a potential target of miR-130b. Interestingly, miR-130b potently repressed PGC1α expression by targeting both the PGC1α mRNA coding and 3' untranslated regions. These findings have some insight of miR-130b in mediating adipocyte differentiation by repressing PGC1α expression and this contributes to further understanding about the functional significance of miRNAs in milk fat synthesis. PMID:26579707

  16. MiR130b-Regulation of PPARγ Coactivator- 1α Suppresses Fat Metabolism in Goat Mammary Epithelial Cells

    PubMed Central

    Chen, Zhi; Luo, Jun; Ma, LiuAn; Wang, Hui; Cao, WenTing; Xu, HuiFei; Zhu, JiangJiang; Sun, YuTing; Li, Jun; Yao, DaWei; Kang, Kang; Gou, Deming

    2015-01-01

    Fat metabolism is a complicated process regulated by a series of factors. microRNAs (miRNAs) are a class of negative regulator of proteins and play crucial roles in many biological processes; including fat metabolism. Although there have been some researches indicating that miRNAs could influence the milk fat metabolism through targeting some factors, little is known about the effect of miRNAs on goat milk fat metabolism. Here we utilized an improved miRNA detection assay, S-Poly-(T), to profile the expression of miRNAs in the goat mammary gland in different periods, and found that miR-130b was abundantly and differentially expressed in goat mammary gland. Additionally, overexpressing miR-130b impaired adipogenesis while inhibiting miR-130b enhanced adipogenesis in goat mammary epithelial cells. Utilizing 3’-UTR assay and Western Blot analusis, the protein peroxisome proliferator-activated receptor coactivator-1α (PGC1α), a major regulator of fat metabolism, was demonstrated to be a potential target of miR-130b. Interestingly, miR-130b potently repressed PGC1α expression by targeting both the PGC1α mRNA coding and 3’ untranslated regions. These findings have some insight of miR-130b in mediating adipocyte differentiation by repressing PGC1α expression and this contributes to further understanding about the functional significance of miRNAs in milk fat synthesis. PMID:26579707

  17. Integration host factor and LuxR synergistically bind DNA to coactivate quorum-sensing genes in Vibrio harveyi.

    PubMed

    Chaparian, Ryan R; Olney, Stephen G; Hustmyer, Christine M; Rowe-Magnus, Dean A; van Kessel, Julia C

    2016-09-01

    The cell-cell signaling process called quorum sensing allows bacteria to control behaviors in response to changes in population density. In Vibrio harveyi, the master quorum-sensing transcription factor LuxR is a member of the TetR family of transcription factors that both activates and represses genes to coordinate group behaviors, including bioluminescence. Here, we show that integration host factor (IHF) is a key coactivator of the luxCDABE bioluminescence genes that is required together with LuxR for precise timing and expression levels of bioluminescence during quorum sensing. IHF binds to multiple sites in the luxCDABE promoter and bends the DNA in vitro. IHF and LuxR synergistically bind luxCDABE promoter DNA at overlapping, essential binding sites that are required for maximal gene expression in vivo. RNA-seq analysis demonstrated that IHF regulates 300 genes in V. harveyi, and among these are a core set of 19 genes that are also directly bound and regulated by LuxR. We validated these global analyses by demonstrating that both IHF and LuxR are required for transcriptional activation of the osmotic stress response genes betIBA-proXWV. These data suggest that IHF plays an integral role in one mechanism of transcriptional activation by the LuxR-type family of quorum-sensing regulators in vibrios. PMID:27191515

  18. The RXR{alpha} C-terminus T462 is a NMR sensor for coactivator peptide binding

    SciTech Connect

    Lu Jianyun Chen Minghe; DeKoster, Gregory T.; Cistola, David P.; Li, Ellen

    2008-02-22

    The C-terminal activation function-2 (AF-2) helix plays a crucial role in retinoid X receptor alpha (RXR{alpha})-mediated gene expression. Here, we report a nuclear magnetic resonance (NMR) study of the RXR{alpha} ligand-binding domain complexed with 9-cis-retinoic acid and a glucocorticoid receptor-interacting protein 1 peptide. The AF-2 helix and most of the C-terminal residues were undetectable due to a severe line-broadening effect. Due to its outstanding signal-to-noise ratio, the C-terminus residue, threonine 462 (T462) exhibited two distinct crosspeaks during peptide titration, suggesting that peptide binding was in a slow exchange regime on the chemical shift timescale. Consistently, the K{sub d} derived from T462 intensity decay agreed with that derived from isothermal titration calorimetry. Furthermore, the exchange contribution to the {sup 15}N transverse relaxation rate was measurable in either T462 or the bound peptide. These results suggest that T462 is a sensor for coactivator binding and is a potential probe for AF-2 helix mobility.

  19. YAP/TEAD Co-Activator Regulated Pluripotency and Chemoresistance in Ovarian Cancer Initiated Cells

    PubMed Central

    Yu, Chao; Chang, Ting; Fan, Heng-Yu

    2014-01-01

    Recent evidence suggests that some solid tumors, including ovarian cancer, contain distinct populations of stem cells that are responsible for tumor initiation, growth, chemo-resistance, and recurrence. The Hippo pathway has attracted considerable attention and some investigators have focused on YAP functions for maintaining stemness and cell differentiation. In this study, we successfully isolated the ovarian cancer initiating cells (OCICs) and demonstrated YAP promoted self-renewal of ovarian cancer initiated cell (OCIC) through its downstream co-activator TEAD. YAP and TEAD families were required for maintaining the expression of specific genes that may be involved in OCICs' stemness and chemoresistance. Taken together, our data first indicate that YAP/TEAD co-activator regulated ovarian cancer initiated cell pluripotency and chemo-resistance. It proposed a new mechanism on the drug resistance in cancer stem cell that Hippo-YAP signal pathway might serve as therapeutic targets for ovarian cancer treatment in clinical. PMID:25369529

  20. Steroid receptor coactivator 1 links the steroid and interferon gamma response pathways.

    PubMed

    Tzortzakaki, Eleni; Spilianakis, Charalambos; Zika, Eleni; Kretsovali, Androniki; Papamatheakis, Joseph

    2003-12-01

    We show here that steroid receptor coactivator 1 (SRC-1) is a coactivator of MHC class II genes that stimulates their interferon gamma (IFNgamma) and class II transactivator (CIITA)-mediated expression. SRC-1 interacts physically with the N-terminal activation domain of CIITA through two regions: one central [extending from amino acids (aa) 360-839] that contains the nuclear receptors binding region and one C-terminal (aa 1138-1441) that contains the activation domain 2. Using chromatin immunoprecipitation assays we show that SRC-1 recruitment on the class II promoter is enhanced upon IFNgamma stimulation. Most importantly, SRC-1 relieves the inhibitory action of estrogens on the IFNgamma-mediated induction of class II genes in transient transfection assays. We provide evidence that inhibition by estradiol is due to multiple events such as slightly reduced recruitment of CIITA and SRC-1 and severely inhibited assembly of the preinitiation complex. PMID:12933903

  1. Listening to Puns Elicits the Co-Activation of Alternative Homophone Meanings during Language Production.

    PubMed

    Rose, Sebastian Benjamin; Spalek, Katharina; Rahman, Rasha Abdel

    2015-01-01

    Recent evidence suggests that lexical-semantic activation spread during language production can be dynamically shaped by contextual factors. In this study we investigated whether semantic processing modes can also affect lexical-semantic activation during word production. Specifically, we tested whether the processing of linguistic ambiguities, presented in the form of puns, has an influence on the co-activation of unrelated meanings of homophones in a subsequent language production task. In a picture-word interference paradigm with word distractors that were semantically related or unrelated to the non-depicted meanings of homophones we found facilitation induced by related words only when participants listened to puns before object naming, but not when they heard jokes with unambiguous linguistic stimuli. This finding suggests that a semantic processing mode of ambiguity perception can induce the co-activation of alternative homophone meanings during speech planning. PMID:26114942

  2. Listening to Puns Elicits the Co-Activation of Alternative Homophone Meanings during Language Production

    PubMed Central

    Rose, Sebastian Benjamin; Spalek, Katharina; Rahman, Rasha Abdel

    2015-01-01

    Recent evidence suggests that lexical-semantic activation spread during language production can be dynamically shaped by contextual factors. In this study we investigated whether semantic processing modes can also affect lexical-semantic activation during word production. Specifically, we tested whether the processing of linguistic ambiguities, presented in the form of puns, has an influence on the co-activation of unrelated meanings of homophones in a subsequent language production task. In a picture-word interference paradigm with word distractors that were semantically related or unrelated to the non-depicted meanings of homophones we found facilitation induced by related words only when participants listened to puns before object naming, but not when they heard jokes with unambiguous linguistic stimuli. This finding suggests that a semantic processing mode of ambiguity perception can induce the co-activation of alternative homophone meanings during speech planning. PMID:26114942

  3. Coactivation of GR and NFKB alters the repertoire of their binding sites and target genes

    PubMed Central

    Rao, Nagesha A.S.; McCalman, Melysia T.; Moulos, Panagiotis; Francoijs, Kees-Jan; Chatziioannou, Aristotelis; Kolisis, Fragiskos N.; Alexis, Michael N.; Mitsiou, Dimitra J.; Stunnenberg, Hendrik G.

    2011-01-01

    Glucocorticoid receptor (GR) exerts anti-inflammatory action in part by antagonizing proinflammatory transcription factors such as the nuclear factor kappa-b (NFKB). Here, we assess the crosstalk of activated GR and RELA (p65, major NFKB component) by global identification of their binding sites and target genes. We show that coactivation of GR and p65 alters the repertoire of regulated genes and results in their association with novel sites in a mutually dependent manner. These novel sites predominantly cluster with p65 target genes that are antagonized by activated GR and vice versa. Our data show that coactivation of GR and NFKB alters signaling pathways that are regulated by each factor separately and provide insight into the networks underlying the GR and NFKB crosstalk. PMID:21750107

  4. Absence of the SRC-2 Coactivator Results in a Glycogenopathy Resembling Von Gierke's Disease

    PubMed Central

    Chopra, Atul R.; Louet, Jean-Francois; Saha, Pradip; An, Jie; DeMayo, Franco; Xu, Jianming; York, Brian; Karpen, Saul; Finegold, Milton; Moore, David; Chan, Lawrence; Newgard, Christopher B.; O'Malley, Bert W.

    2009-01-01

    Hepatic glucose production is critical for basal brain function and survival when dietary glucose is unavailable. Glucose-6-phosphatase (G6Pase) is an essential, rate-limiting enzyme that serves as a terminal gatekeeper for hepatic glucose release into the plasma. Mutations in G6Pase result in Von Gierke's disease (glycogen storage disease–1a), a potentially fatal genetic disorder. We have identified the transcriptional coactivator SRC-2 as a regulator of fasting hepatic glucose release, a function that SRC-2 performs by controlling the expression of hepatic G6Pase. SRC-2 modulates G6Pase expression directly by acting as a coactivator with the orphan nuclear receptor RORα. In addition, SRC-2 ablation, in both a whole-body and liver-specific manner, resulted in a Von Gierke's disease phenotype in mice. Our results position SRC-2 as a critical regulator of mammalian glucose production. PMID:19039140

  5. Steroid Receptor Coactivators: Servants and Masters for Control of Systems Metabolism

    PubMed Central

    Stashi, Erin; York, Brian; O’Malley, Bert W.

    2014-01-01

    Coregulator recruitment to nuclear receptors (NRs) and other transcription factors is essential for proper metabolic gene regulation with coactivators enhancing and corepressors attenuating gene transcription. The Steroid Receptor Coactivator (SRC) family is composed of three homologous members (SRC-1, SRC-2, and SRC-3), which are uniquely important for mediating steroid hormone and mitogenic actions. An accumulating body of work highlights the diverse array of metabolic functions regulated by the SRCs, including systemic metabolite homeostasis, inflammation, and energy regulation. Here we discuss the cooperative and unique functions among the SRCs to provide a comprehensive atlas of systemic SRC metabolic regulation. Deciphering the fractional and synergistic contributions of the SRCs to metabolic homeostasis is critical to fully understand the networks underlying metabolic transcriptional regulation. PMID:24953190

  6. Absence of the SRC-2 coactivator results in a glycogenopathy resembling Von Gierke's disease.

    PubMed

    Chopra, Atul R; Louet, Jean-Francois; Saha, Pradip; An, Jie; Demayo, Franco; Xu, Jianming; York, Brian; Karpen, Saul; Finegold, Milton; Moore, David; Chan, Lawrence; Newgard, Christopher B; O'Malley, Bert W

    2008-11-28

    Hepatic glucose production is critical for basal brain function and survival when dietary glucose is unavailable. Glucose-6-phosphatase (G6Pase) is an essential, rate-limiting enzyme that serves as a terminal gatekeeper for hepatic glucose release into the plasma. Mutations in G6Pase result in Von Gierke's disease (glycogen storage disease-1a), a potentially fatal genetic disorder. We have identified the transcriptional coactivator SRC-2 as a regulator of fasting hepatic glucose release, a function that SRC-2 performs by controlling the expression of hepatic G6Pase. SRC-2 modulates G6Pase expression directly by acting as a coactivator with the orphan nuclear receptor RORalpha. In addition, SRC-2 ablation, in both a whole-body and liver-specific manner, resulted in a Von Gierke's disease phenotype in mice. Our results position SRC-2 as a critical regulator of mammalian glucose production. PMID:19039140

  7. 'Co-active coaching' could help HIV patients. New type of counseling involves goal-setting.

    PubMed

    Garfinkel, M; Blumenthal, E

    2001-08-01

    A counseling technique that takes an action-oriented approach to helping people make major life changes, much used by business executives and other professionals in recent years, now appears to offer some value to HIV patients. Co-active coaching could be a solution to mild depression and inertia for some HIV-infected patients who have difficulty making decisions about how to spend a life-time living with the disease. PMID:11547701

  8. Transient neuronal coactivations embedded in globally propagating waves underlie resting-state functional connectivity.

    PubMed

    Matsui, Teppei; Murakami, Tomonari; Ohki, Kenichi

    2016-06-01

    Resting-state functional connectivity (FC), which measures the correlation of spontaneous hemodynamic signals (HemoS) between brain areas, is widely used to study brain networks noninvasively. It is commonly assumed that spatial patterns of HemoS-based FC (Hemo-FC) reflect large-scale dynamics of underlying neuronal activity. To date, studies of spontaneous neuronal activity cataloged heterogeneous types of events ranging from waves of activity spanning the entire neocortex to flash-like activations of a set of anatomically connected cortical areas. However, it remains unclear how these various types of large-scale dynamics are interrelated. More importantly, whether each type of large-scale dynamics contributes to Hemo-FC has not been explored. Here, we addressed these questions by simultaneously monitoring neuronal calcium signals (CaS) and HemoS in the entire neocortex of mice at high spatiotemporal resolution. We found a significant relationship between two seemingly different types of large-scale spontaneous neuronal activity-namely, global waves propagating across the neocortex and transient coactivations among cortical areas sharing high FC. Different sets of cortical areas, sharing high FC within each set, were coactivated at different timings of the propagating global waves, suggesting that spatial information of cortical network characterized by FC was embedded in the phase of the global waves. Furthermore, we confirmed that such transient coactivations in CaS were indeed converted into spatially similar coactivations in HemoS and were necessary to sustain the spatial structure of Hemo-FC. These results explain how global waves of spontaneous neuronal activity propagating across large-scale cortical network contribute to Hemo-FC in the resting state. PMID:27185944

  9. Awakening the Hippo co-activator YAP1, a mercurial cancer gene, in hematologic cancers

    PubMed Central

    Cottini, Francesca; Anderson, Kenneth C; Tonon, Giovanni

    2014-01-01

    Unrestrained oncogene activity triggers DNA damage. Cancer cells exploit various stratagems to deal with this potentially lethal event. We found that hematologic cancer cells inactivate the Hippo co-activator Yes-associated protein 1 (YAP1). A synthetic lethal approach is proposed whereby inhibition of the serine/threonine kinase 4 (STK4) could be exploited to restore YAP1 levels in hematologic cancers.

  10. Nuclear Control of Respiratory Chain Expression by Nuclear Respiratory Factors and PGC-1-Related Coactivator

    PubMed Central

    Scarpulla, Richard C.

    2010-01-01

    Expression of the respiratory apparatus depends on both nuclear and mitochondrial genes. Although these genes are sequestered in distinct cellular organelles, their transcription relies on nucleus-encoded factors. Certain of these factors are directed to the mitochondria, where they sponsor the bi-directional transcription of mitochondrial DNA. Others act on nuclear genes that encode the majority of the respiratory subunits and many other gene products required for the assembly and function of the respiratory chain. The nuclear respiratory factors, NRF-1 and NRF-2, contribute to the expression of respiratory subunits and mitochondrial transcription factors and thus have been implicated in nucleo-mitochondrial interactions. In addition, coactivators of the PGC-1 family serve as mediators between the environment and the transcriptional machinery governing mitochondrial biogenesis. One family member, peroxisome proliferator-activated receptor γ coactivator PGC-1-related coactivator (PRC), is an immediate early gene product that is rapidly induced by mitogenic signals in the absence of de novo protein synthesis. Like other PGC-1 family members, PRC binds NRF-1 and activates NRF-1 target genes. In addition, PRC complexes with NRF-2 and HCF-1 (host cell factor-1) in the activation of NRF-2-dependent promoters. HCF-1 functions in cell-cycle progression and has been identified as an NRF-2 coactivator. The association of these factors with PRC is suggestive of a role for the complex in cell growth. Finally, shRNA-mediated knock down of PRC expression results in a complex phenotype that includes the inhibition of respiratory growth on galactose and the loss of respiratory complexes. Thus, PRC may help integrate the expression of the respiratory apparatus with the cell proliferative program. PMID:19076454

  11. A novel meta-analytic approach: Mining frequent co-activation patterns in neuroimaging databases

    PubMed Central

    Caspers, Julian; Zilles, Karl; Beierle, Christoph; Rottschy, Claudia; Eickhoff, Simon B.

    2016-01-01

    In recent years, coordinate-based meta-analyses have become a powerful and widely used tool to study coactivity across neuroimaging experiments, a development that was supported by the emergence of large-scale neuroimaging databases like BrainMap. However, the evaluation of co-activation patterns is constrained by the fact that previous coordinate-based meta-analysis techniques like Activation Likelihood Estimation (ALE) and Multilevel Kernel Density Analysis (MKDA) reveal all brain regions that show convergent activity within a dataset without taking into account actual within-experiment co-occurrence patterns. To overcome this issue we here propose a novel meta-analytic approach named PaMiNI that utilizes a combination of two well-established data-mining techniques, Gaussian mixture modeling and the Apriori algorithm. By this, PaMiNI enables a data-driven detection of frequent co-activation patterns within neuroimaging datasets. The feasibility of the method is demonstrated by means of several analyses on simulated data as well as a real application. The analyses of the simulated data show that PaMiNI identifies the brain regions underlying the simulated activation foci and perfectly separates the co-activation patterns of the experiments in the simulations. Furthermore, PaMiNI still yields good results when activation foci of distinct brain regions become closer together or if they are non-Gaussian distributed. For the further evaluation, a real dataset on working memory experiments is used, which was previously examined in an ALE meta-analysis and hence allows a cross-validation of both methods. In this latter analysis, PaMiNI revealed a fronto-parietal “core” network of working memory and furthermore indicates a left-lateralization in this network. Finally, to encourage a widespread usage of this new method, the PaMiNI approach was implemented into a publicly available software system. PMID:24365675

  12. Multi-scale complexity analysis of muscle coactivation during gait in children with cerebral palsy

    PubMed Central

    Tao, Wen; Zhang, Xu; Chen, Xiang; Wu, De; Zhou, Ping

    2015-01-01

    The objective of this study is to characterize complexity of lower-extremity muscle coactivation and coordination during gait in children with cerebral palsy (CP), children with typical development (TD) and healthy adults, by applying recently developed multivariate multi-scale entropy (MMSE) analysis to surface electromyographic (EMG) signals. Eleven CP children (CP group), eight TD children and seven healthy adults (considered as an entire control group) were asked to walk while surface EMG signals were collected from five thigh muscles and three lower leg muscles on each leg (16 EMG channels in total). The 16-channel surface EMG data, recorded during a series of consecutive gait cycles, were simultaneously processed by multivariate empirical mode decomposition (MEMD), to generate fully aligned data scales for subsequent MMSE analysis. In order to conduct extensive examination of muscle coactivation complexity using the MEMD-enhanced MMSE, 14 data analysis schemes were designed by varying partial muscle combinations and time durations of data segments. Both TD children and healthy adults showed almost consistent MMSE curves over multiple scales for all the 14 schemes, without any significant difference (p > 0.09). However, distinct diversity in MMSE curve was observed in the CP group when compared with the control group. There appears to be diverse neuropathological processes in CP that may affect dynamical complexity of muscle coactivation and coordination during gait. The abnormal complexity patterns emerging in the CP group can be attributed to different factors such as motor control impairments, loss of muscle couplings, and spasticity or paralysis in individual muscles. This study expands our knowledge of neuropathology of CP from a novel point of view of muscle co-activation complexity, which might be useful to derive a quantitative index for assessing muscle activation characteristics as well as motor function in CP. PMID:26257622

  13. p300 is a component of an estrogen receptor coactivator complex.

    PubMed

    Hanstein, B; Eckner, R; DiRenzo, J; Halachmi, S; Liu, H; Searcy, B; Kurokawa, R; Brown, M

    1996-10-15

    The estrogen receptor (ER) is a ligand-dependent transcription factor that regulates expression of target genes in response to estrogen in concert with other cellular signaling pathways. This suggests that the mechanism by which ER transmits an activating signal to the general transcription machinery may include factors that integrate these diverse signals. We have previously characterized the estrogen receptor-associated protein, ERAP160, as a factor that complexes with ER in an agonist-dependent manner. We have now found that the transcriptional coactivator p300 associates with agonist bound ER and augments ligand-dependent activation by ER. Our studies show that an ER coactivator complex involves a direct hormone-dependent interaction between ER and ERAP160, resulting in the recruitment of p300. In addition, antibodies directed against the cloned steroid receptor coactivator 1 (SRC1) recognize ERAP160. The known role of p300 in multiple signal transduction pathways, including those involving the second messenger cAMP, suggests p300 functions as a point of integration between ER and these other pathways. PMID:8876171

  14. Identification of the functional domains of ANT-1, a novel coactivator of the androgen receptor

    SciTech Connect

    Fan Shuli; Goto, Kiminobu; Chen Guangchun; Morinaga, Hidetaka; Nomura, Masatoshi; Okabe, Taijiro; Nawata, Hajime; Yanase, Toshihiko . E-mail: yanase@intmed3.med.kyushu-u.ac.jp

    2006-03-03

    Previously, we identified a transcriptional coactivator for the activation function-1 (AF-1) domain of the human androgen receptor (AR) and designated it androgen receptor N-terminal domain transactivating protein-1 (ANT-1). This coactivator, which contains multiple tetratricopeptide repeat (TPR) motifs from amino acid (aa) 294, is identical to a component of U5 small nuclear ribonucleoprotein particles and binds specifically to the AR or glucocorticoid receptor. Here, we identified four distinct functional domains. The AR-AF-1-binding domain, which bound to either aa 180-360 or 360-532 in AR-AF-1, clearly overlapped with TAU-1 and TAU-5. This domain and the subnuclear speckle formation domain in ANT-1 were assigned within the TPR motifs, while the transactivating and nuclear localization signal domains resided within the N-terminal sequence. The existence of these functional domains may further support the idea that ANT-1 can function as an AR-AF-1-specific coactivator while mediating a transcription-splicing coupling.

  15. A temporal examination of co-activated emotion valence networks in schizophrenia and schizotypy.

    PubMed

    Cohen, Alex S; Callaway, Dallas A; Mitchell, Kyle R; Larsen, Jeff T; Strauss, Gregory P

    2016-02-01

    Emotional abnormalities are prominent across the schizophrenia spectrum. To better define these abnormalities, we examined state emotional functions across opposing ends of the spectrum, notably in chronic outpatients with schizophrenia (Study 1) and college students with psychometrically defined schizotypy (Study 2). In line with existing studies, we predicted that individuals with schizophrenia would show unusually co-activated positive and negative emotions while college students with schizotypy would show abnormally low positive and abnormally high negative emotions. Drawing from the affective science literature, we employed continuous emotion ratings in response to a dynamic and evocatively "bittersweet" stimulus. Participants included 27 individuals with schizophrenia, 39 individuals with psychometrically defined schizotypy and 26 community and 35 college control participants. Participants continuously rated their state happiness and sadness throughout a six-minute clip from a tragicomic film (i.e., Life is Beautiful). In contrast to expectations as well as the extant literature, there were no state emotional abnormalities noted from either schizophrenia-spectrum group. Of particular note, neither individuals with schizophrenia nor individuals with schizotypy were abnormal in their experience of state negative, positive or coactivated emotions. Conversely, abnormalities in trait emotion were observed in both groups relative to their respective control groups. These results help confirm that the schizophrenia-spectrum is not characterized by deficits in state emotional experience and suggest that sadness is not abnormally co-activated with pleasant emotions. These results are critical for clarifying the "chronometry" of emotional dysfunctions across the schizophrenia-spectrum. PMID:26711714

  16. Pax6 represses androgen receptor-mediated transactivation by inhibiting recruitment of the coactivator SPBP.

    PubMed

    Elvenes, Julianne; Thomassen, Ernst Ivan Simon; Johnsen, Sylvia Sagen; Kaino, Katrine; Sjøttem, Eva; Johansen, Terje

    2011-01-01

    The androgen receptor (AR) has a central role in development and maintenance of the male reproductive system and in the etiology of prostate cancer. The transcription factor Pax6 has recently been reported to act as a repressor of AR and to be hypermethylated in prostate cancer cells. SPBP is a transcriptional regulator that previously has been shown to enhance the activity of Pax6. In this study we have identified SPBP to act as a transcriptional coactivator of AR. We also show that Pax6 inhibits SPBP-mediated enhancement of AR activity on the AR target gene probasin promoter, a repression that was partly reversed by increased expression of SPBP. Enhanced expression of Pax6 reduced the amount of SPBP associated with the probasin promoter when assayed by ChIP in HeLa cells. We mapped the interaction between both AR and SPBP, and AR and Pax6 to the DNA-binding domains of the involved proteins. Further binding studies revealed that Pax6 and SPBP compete for binding to AR. These results suggest that Pax6 represses AR activity by displacing and/or inhibiting recruitment of coactivators to AR target promoters. Understanding the mechanism for inhibition of AR coactivators can give rise to molecular targeted drugs for treatment of prostate cancer. PMID:21935435

  17. Pax6 Represses Androgen Receptor-Mediated Transactivation by Inhibiting Recruitment of the Coactivator SPBP

    PubMed Central

    Johnsen, Sylvia Sagen; Kaino, Katrine; Sjøttem, Eva; Johansen, Terje

    2011-01-01

    The androgen receptor (AR) has a central role in development and maintenance of the male reproductive system and in the etiology of prostate cancer. The transcription factor Pax6 has recently been reported to act as a repressor of AR and to be hypermethylated in prostate cancer cells. SPBP is a transcriptional regulator that previously has been shown to enhance the activity of Pax6. In this study we have identified SPBP to act as a transcriptional coactivator of AR. We also show that Pax6 inhibits SPBP-mediated enhancement of AR activity on the AR target gene probasin promoter, a repression that was partly reversed by increased expression of SPBP. Enhanced expression of Pax6 reduced the amount of SPBP associated with the probasin promoter when assayed by ChIP in HeLa cells. We mapped the interaction between both AR and SPBP, and AR and Pax6 to the DNA-binding domains of the involved proteins. Further binding studies revealed that Pax6 and SPBP compete for binding to AR. These results suggest that Pax6 represses AR activity by displacing and/or inhibiting recruitment of coactivators to AR target promoters. Understanding the mechanism for inhibition of AR coactivators can give rise to molecular targeted drugs for treatment of prostate cancer. PMID:21935435

  18. PRIC320, a transcription coactivator, isolated from peroxisome proliferator-binding protein complex

    SciTech Connect

    Surapureddi, Sailesh; Viswakarma, Navin; Yu Songtao; Guo Dongsheng; Rao, M. Sambasiva; Reddy, Janardan K. . E-mail: jkreddy@northwestern.edu

    2006-05-05

    Ciprofibrate, a potent peroxisome proliferator, induces pleiotropic responses in liver by activating peroxisome proliferator-activated receptor {alpha} (PPAR{alpha}), a nuclear receptor. Transcriptional regulation by liganded nuclear receptors involves the participation of coregulators that form multiprotein complexes possibly to achieve cell and gene specific transcription. SDS-PAGE and matrix-assisted laser desorption/ionization reflection time-of-flight mass spectrometric analyses of ciprofibrate-binding proteins from liver nuclear extracts obtained using ciprofibrate-Sepharose affinity matrix resulted in the identification of a new high molecular weight nuclear receptor coactivator, which we designated PRIC320. The full-length human cDNA encoding this protein has an open-reading frame that codes for a 320 kDa protein containing 2882 amino acids. PRIC320 contains five LXXLL signature motifs that mediate interaction with nuclear receptors. PRIC320 binds avidly to nuclear receptors PPAR{alpha}, CAR, ER{alpha}, and RXR, but only minimally with PPAR{gamma}. PRIC320 also interacts with transcription cofactors CBP, PRIP, and PBP. Immunoprecipitation-immunoblotting as well as cellular localization studies confirmed the interaction between PPAR{alpha} and PRIC320. PRIC320 acts as a transcription coactivator by stimulating PPAR{alpha}-mediated transcription. We conclude that ciprofibrate, a PPAR{alpha} ligand, binds a multiprotein complex and PRIC320 cloned from this complex functions as a nuclear receptor coactivator.

  19. SRC-2 Is an Essential Coactivator for Orchestrating Metabolism and Circadian Rhythm

    PubMed Central

    Stashi, Erin; Lanz, Rainer B.; Mao, Jianqiang; Michailidis, George; Zhu, Bokai; Kettner, Nicole M.; Putluri, Nagireddy; Reineke, Erin L.; Reineke, Lucas C.; Dasgupta, Subhamoy; Dean, Adam; Stevenson, Connor R.; Sivasubramanian, Natarajan; Sreekumar, Arun; DeMayo, Francesco; York, Brian; Fu, Loning; O'Malley, Bert W.

    2014-01-01

    SUMMARY Synchrony of the mammalian circadian clock is achieved by complex transcriptional and translational feedback loops centered on the BMAL1: CLOCK heterodimer. Modulation of circadian feedback loops is essential for maintaining rhythmicity, yet the role of transcriptional coactivators in driving BMAL1:CLOCK transcriptional networks is largely unexplored. Here, we show diurnal hepatic steroid receptor coactivator 2 (SRC-2) recruitment to the genome that extensively overlaps with the BMAL1 cistrome during the light phase, targeting genes that enrich for circadian and metabolic processes. Notably, SRC-2 ablation impairs wheel-running behavior, alters circadian gene expression in several peripheral tissues, alters the rhythmicity of the hepatic metabolome, and deregulates the synchronization of cell-autonomous metabolites. We identify SRC-2 as a potent coregulator of BMAL1:CLOCK and find that SRC-2 targets itself with BMAL1:CLOCK in a feedforward loop. Collectively, our data suggest that SRC-2 is a transcriptional coactivator of the BMAL1:CLOCK oscillators and establish SRC-2 as a critical positive regulator of the mammalian circa-dian clock. PMID:24529706

  20. Physical and functional interactions of human papillomavirus E2 protein with nuclear receptor coactivators

    SciTech Connect

    Wu, M.-H.; Huang, C.-J.; Liu, S.-T.; Liu, P.-Y.; Ho, C.-L. . E-mail: shihming@ndmctsgh.edu.tw

    2007-05-11

    In addition to the human papillomavirus (HPV)-induced immortalization of epithelial cells, which usually requires integration of the viral DNA into the host cell genome, steroid hormone-activated nuclear receptors (NRs) are thought to bind to specific DNA sequences within transcriptional regulatory regions on the long control region to either increase or suppress transcription of dependent genes. In this study, our data suggest that the NR coactivator function of HPV E2 proteins might be mediated through physical and functional interactions with not only NRs but also the NR coactivators GRIP1 (glucocorticoid receptor-interacting protein 1) and Zac1 (zinc-finger protein which regulates apoptosis and cell cycle arrest 1), reciprocally regulating their transactivation activities. GRIP1 and Zac1 both were able to act synergistically with HPV E2 proteins on the E2-, androgen receptor-, and estrogen receptor-dependent transcriptional activation systems. GRIP1 and Zac1 might selectively function with HPV E2 proteins on thyroid receptor- and p53-dependent transcriptional activation, respectively. Hence, the transcriptional function of E2 might be mediated through NRs and NR coactivators to regulate E2-, NR-, and p53-dependent transcriptional activations.

  1. Play Therapy: A Review

    ERIC Educational Resources Information Center

    Porter, Maggie L.; Hernandez-Reif, Maria; Jessee, Peggy

    2009-01-01

    This article discusses the current issues in play therapy and its implications for play therapists. A brief history of play therapy is provided along with the current play therapy approaches and techniques. This article also touches on current issues or problems that play therapists may face, such as interpreting children's play, implementing…

  2. The Denial of Play.

    ERIC Educational Resources Information Center

    Sutton-Smith, Brian

    Well meaning parents and teachers often use children's play for the purposes of literacy and socialization. Yet, these attempts may deny play to children by subordinating play to some other concept. Evidence shows that even when parents play with their very young children they generally play games like shopping, cooking, and eating; whereas when…

  3. War, Conflict and Play. Debating Play

    ERIC Educational Resources Information Center

    Hyder, Tina

    2004-01-01

    Young refugees from many parts of the world are increasingly present in UK early years settings. This book explores the crucial importance of play for young refugee children's development. It considers the implications of war and conflict on young children and notes how opportunities for play are denied. It provides a framework for early years…

  4. Playing the Play: What the Children Want

    ERIC Educational Resources Information Center

    Kraus, Jo Anne

    2006-01-01

    Playing the Play describes the experiences of a storyteller and teacher of literature who created a literature-based literacy program at Concourse House, a homeless shelter in Bronx, New York, for women and their young children. This program is based on the belief that pleasure is the primary reason children want to learn to read, and that where…

  5. Bibliography on Play Therapy and Children's Play.

    ERIC Educational Resources Information Center

    Rogers, Mary Brown; L'Abate, Luciano

    The references listed are: (1) journals, (2) dissertation abstracts, (3) books, (4) reports, and (5) monographs. The main subjects covered are: (1) children's play, (2) psychotherapy with disturbed children through the medium of play therapy, and (3) various aspects of child development, both normal and abnormal. The materials listed date from…

  6. The Uses of Play

    ERIC Educational Resources Information Center

    Cabaniss, Thomas

    2005-01-01

    Teaching artists have techniques for keeping play alive and vital in their work. But how do they think of play as TAs? In this article, the author examines the role of play in the work and life of teaching artists.

  7. Reducing abnormal muscle co-activation after stroke using a myoelectric-computer interface: a pilot study

    PubMed Central

    Wright, Zachary A.; Zev Rymer, W.; Slutzky, Marc W.

    2014-01-01

    Background A significant factor in impaired movement caused by stroke is the inability to activate muscles independently. While the pathophysiology behind this abnormal co-activation is not clear, reducing the co-activation could improve overall arm function. A myoelectric computer interface (MCI), which maps EMG signals to cursor movement, could be used as a treatment to help retrain muscle activation patterns. Objective To investigate the use of MCI training to reduce abnormal muscle co-activation in chronic stroke survivors. Methods Five healthy subjects and five stroke survivors with hemiparesis participated in multiple sessions of MCI training. The level of arm impairment in stroke survivors was assessed using the upper extremity portion of Fugl-Meyer Motor Assessment (FMA-UE). Subjects performed isometric activations of up to five muscles. Activation of each muscle was mapped to different directions of cursor movement. The MCI specifically targeted one pair of muscles in each subject for reduction of co-activation. Results Both healthy subjects and stroke survivors learned to reduce abnormal co-activation of the targeted muscles with MCI training. Three out of five stroke survivors exhibited objective reduction in arm impairment as well (improvement in FMA-UE of 3 points in each of these subjects). Conclusions These results suggest that the MCI was an effective tool in directly retraining muscle activation patterns following stroke. PMID:24376069

  8. Research Resource: Tissue- and Pathway-Specific Metabolomic Profiles of the Steroid Receptor Coactivator (SRC) Family

    PubMed Central

    York, Brian; Sagen, Jørn V.; Tsimelzon, Anna; Louet, Jean-Francios; Chopra, Atul R.; Reineke, Erin L.; Zhou, Suoling; Stevens, Robert D.; Wenner, Brett R.; Ilkayeva, Olga; Bain, James R.; Xu, Jianming; Hilsenbeck, Susan G.; Newgard, Christopher B.

    2013-01-01

    The rapidly growing family of transcriptional coregulators includes coactivators that promote transcription and corepressors that harbor the opposing function. In recent years, coregulators have emerged as important regulators of metabolic homeostasis, including the p160 steroid receptor coactivator (SRC) family. Members of the SRC family have been ascribed important roles in control of gluconeogenesis, fat absorption and storage in the liver, and fatty acid oxidation in skeletal muscle. To provide a deeper and more granular understanding of the metabolic impact of the SRC family members, we performed targeted metabolomic analyses of key metabolic byproducts of glucose, fatty acid, and amino acid metabolism in mice with global knockouts (KOs) of SRC-1, SRC-2, or SRC-3. We measured amino acids, acyl carnitines, and organic acids in five tissues with key metabolic functions (liver, heart, skeletal muscle, brain, plasma) isolated from SRC-1, -2, or -3 KO mice and their wild-type littermates under fed and fasted conditions, thereby unveiling unique metabolic functions of each SRC. Specifically, SRC-1 ablation revealed the most significant impact on hepatic metabolism, whereas SRC-2 appeared to impact cardiac metabolism. Conversely, ablation of SRC-3 primarily affected brain and skeletal muscle metabolism. Surprisingly, we identified very few metabolites that changed universally across the three SRC KO models. The findings of this Research Resource demonstrate that coactivator function has very limited metabolic redundancy even within the homologous SRC family. Furthermore, this work also demonstrates the use of metabolomics as a means for identifying novel metabolic regulatory functions of transcriptional coregulators. PMID:23315938

  9. Validation of chemical compound library screening for transcriptional co-activator with PDZ-binding motif inhibitors using GFP-fused transcriptional co-activator with PDZ-binding motif.

    PubMed

    Nagashima, Shunta; Maruyama, Junichi; Kawano, Shodai; Iwasa, Hiroaki; Nakagawa, Kentaro; Ishigami-Yuasa, Mari; Kagechika, Hiroyuki; Nishina, Hiroshi; Hata, Yutaka

    2016-06-01

    Transcriptional co-activator with PDZ-binding motif (TAZ) plays versatile roles in cell proliferation and differentiation. It is phosphorylated by large tumor suppressor kinases, the core kinases of the tumor-suppressive Hippo pathway. Phosphorylation induces the cytoplasmic accumulation of TAZ and its degradation. In human cancers, the deregulation of the Hippo pathway and gene amplification enhance TAZ activity. TAZ interacts with TEA domain family members (TEAD), and upregulates genes implicated in epithelial-mesenchymal transition. It also confers stemness to cancer cells. Thus, TAZ activation provides cancer cells with malignant properties and worsens the clinical prognosis. Therefore, TAZ attracts attention as a therapeutic target in cancer therapy. We applied 18 606 small chemical compounds to human osteosarcoma U2OS cells expressing GFP-fused TAZ (GFP-TAZ), monitored the subcellular localization of GFP-TAZ, and selected 33 compounds that shifted GFP-TAZ to the cytoplasm. Unexpectedly, only a limited number of compounds suppressed TAZ-mediated enhancement of TEAD-responsive reporter activity. Moreover, the compounds that weakened TEAD reporter activity did not necessarily decrease the unphosphorylated TAZ. In this study, we focused on three compounds that decreased both TEAD reporter activity and unphosphorylated TAZ, and treated several human cancer cells with these compounds. One compound did not show a remarkable effect, whereas the other two compounds compromised the cell viability in certain cancer cells. In conclusion, the GFP-TAZ-based assay can be used as the first screening for compounds that inhibit TAZ and show anticancer properties. To develop anticancer drugs, we need additional assays to select the compounds. PMID:27009852

  10. The Role of Steroid Receptor Coactivators in Hormone Dependent Cancers and Their Potential as Therapeutic Targets.

    PubMed

    Wang, Lei; Lonard, David M; O'Malley, Bert W

    2016-08-01

    Steroid receptor coactivator (SRC) family members (SRC-1, SRC-2, SRC-3) interact with nuclear receptors (NRs) and many transcription factors to enhance target gene transcription. Deregulation of SRCs is widely implicated in NR mediated diseases, especially hormone dependent cancers. By integrating steroid hormone signaling and growth factor pathways, SRC proteins exert multiple modes of oncogenic regulation in cancers and represent emerging targets for cancer therapeutics. Recent work has identified SRC-targeting agents that show promise in blocking tumor growth in vitro and in vivo, and have the potential to function as powerful and broadly encompassing treatments for different cancers. PMID:27125199

  11. PGC-1 coactivators and skeletal muscle adaptations in health and disease

    PubMed Central

    2008-01-01

    Skeletal muscle adapts to physiological demands by altering a number of programs of gene expression, including those driving mitochondrial biogenesis, angiogenesis, and fiber composition. Recently, the PGC-1 transcriptional coactivators have emerged as key players in the regulation of these adaptations. Many signaling cascades important in muscle physiology impinge directly on PGC-1 expression or activity. In turn, the PGC-1s powerfully activate many of the programs of muscle adaptation. These findings have implications for our understanding of muscle responses to physiological conditions like exercise, as well as in pathological conditions such as cachexia, dystrophy, and peripheral vascular disease. PMID:18782618

  12. Steroid Receptor Coactivator-2 Expression in Brain and Physical Associations with Steroid Receptors

    PubMed Central

    Yore, Mackensie A.; Im, DaEun; Webb, Lena K.; Zhao, Yingxin; Chadwick, Joseph G.; Molenda-Figueira, Heather A.; Haidacher, Sigmund J.; Denner, Larry; Tetel, Marc J.

    2010-01-01

    Estradiol and progesterone bind to their respective receptors in the hypothalamus and hippocampus to influence a variety of behavioral and physiological functions, including reproduction and cognition. Work from our lab and others has shown that the nuclear receptor coactivators, steroid receptor coactivator-1 (SRC-1) and SRC-2, are essential for efficient estrogen receptor (ER) and progestin receptor (PR) transcriptional activity in brain and for hormone-dependent behaviors. While the expression of SRC-1 in brain has been studied extensively, little is known about the expression of SRC-2 in brain. In the present studies, we found that SRC-2 was highly expressed throughout the hippocampus, amygdala and hypothalamus, including the medial preoptic area (MPOA), ventral medial nucleus (VMN), arcuate nucleus (ARC), bed nucleus of the stria terminalis, supraoptic nucleus and suprachiasmatic nucleus. In order for coactivators to function with steroid receptors, they must be expressed in the same cells. Indeed, SRC-2 and ERα were coexpressed in many cells in the MPOA, VMN and ARC, all brain regions known to be involved in female reproductive behavior and physiology. While in vitro studies indicate that SRC-2 physically associates with ER and PR, very little is known about receptor-coactivator interactions in brain. Therefore, we used pull-down assays to test the hypotheses that SRC-2 from hypothalamic and hippocampal tissue physically associate with ER and PR subtypes in a ligand-dependent manner. SRC-2 from both brain regions interacted with ERα bound to agonist, but not in the absence of ligand or in the presence of the selective ER modulator, tamoxifen. Analysis by mass spectrometry confirmed these ligand-dependent interactions between ERα and SRC-2 from brain. In dramatic contrast, SRC-2 from brain showed little to no interaction with ERβ. Interestingly, SRC-2 from both brain regions interacted with PR-B, but not PR-A, in a ligand-dependent manner. Taken together

  13. Characterization of the human, mouse and rat PGC1 beta (peroxisome-proliferator-activated receptor-gamma co-activator 1 beta) gene in vitro and in vivo.

    PubMed Central

    Meirhaeghe, Aline; Crowley, Vivion; Lenaghan, Carol; Lelliott, Christopher; Green, Kath; Stewart, Abigail; Hart, Kevin; Schinner, Sven; Sethi, Jaswinder K; Yeo, Giles; Brand, Martin D; Cortright, Ron N; O'Rahilly, Stephen; Montague, Carl; Vidal-Puig, Antonio J

    2003-01-01

    PGC1 alpha is a co-activator involved in adaptive thermogenesis, fatty-acid oxidation and gluconeogenesis. We describe the identification of several isoforms of a new human PGC1 alpha homologue, cloned independently and named PGC1 beta. The human PGC1 beta gene is localized to chromosome 5, has 13 exons and spans more than 78 kb. Two different 5' and 3' ends due to differential splicing were identified by rapid amplification of cDNA ends PCR and screening of human cDNA libraries. We show that PGC1 beta variants in humans, mice and rats are expressed predominantly in heart, brown adipose tissue, brain and skeletal muscle. PGC1 beta expression, unlike PGC1 alpha, is not up-regulated in brown adipose tissue in response to cold or obesity. Fasting experiments showed that PGC1 alpha, but not PGC1 beta, is induced in liver and this suggests that only PGC1 alpha is involved in the hepatic gluconeogenesis. No changes in PGC1 beta gene expression were observed associated with exercise. Human PGC1 beta-1a and -2a isoforms localized to the cell nucleus and, specifically, the isoform PGC1 beta-1a co-activated peroxisome-proliferator-activated receptor-gamma, -alpha and the thyroid hormone receptor beta1. Finally, we show that ectopic expression PGC1 beta leads to increased mitochondrial number and basal oxygen consumption. These results suggest that PGC1 beta may play a role in constitutive adrenergic-independent mitochondrial biogenesis. PMID:12678921

  14. Mitochondrial Biogenesis and Peroxisome Proliferator–Activated Receptor-γ Coactivator-1α (PGC-1α) Deacetylation by Physical Activity

    PubMed Central

    Li, Ling; Pan, Ruping; Li, Rong; Niemann, Bernd; Aurich, Anne-Cathleen; Chen, Ying; Rohrbach, Susanne

    2011-01-01

    OBJECTIVE Transcriptional peroxisome proliferator–activated receptor-γ coactivator-1α (PGC-1α) plays a key role in mitochondrial biogenesis and energy metabolism and is suggested to be involved in the exercise-induced increase in mitochondrial content. PGC-1α activity is regulated by posttranslational modifications, among them acetylation or phosphorylation. Accordingly, the deacetylase SIRT1 and the kinase AMPK increase PGC-1α activity. RESEARCH DESIGN AND METHODS We tested whether chronic treadmill exercise or a single exercise session modifies PGC-1α activation and mitochondrial biogenesis differentially in obese ob/ob mice with dysregulated adiponectin/leptin-mediated AMPK activation compared with C57BL/6J wild-type mice. RESULTS Exercise training (12 weeks) induced adiponectin and lowered plasma insulin and glucose, suggesting improved insulin sensitivity in wild-type mice. It enhanced mitochondrial biogenesis in red gastrocnemius muscle, as indicated by increased mRNA expression of transcriptional regulators and primary mitochondrial transcripts, increased mtDNA content, and citrate synthase activity. Parallel to this, we observed AMPK activation, PGC-1α deacetylation, and SIRT1 induction in trained wild-type mice. Although none of these exercise-induced changes were detected in ob/ob mice, comparable effects on mitochondrial respiration were observed. A single exercise session resulted in comparable changes in wild-type mice. These changes remained detectable 6 h after the exercise session but had disappeared after 24 h. Treatment of C2C12 myoblasts with leptin or adiponectin resulted in increased AMPK phosphorylation and PGC-1α deacetylation. CONCLUSIONS Chronic exercise induces mitochondrial biogenesis in wild-type mice, which may require intact AMPK activation by adipocytokines and involve SIRT1-dependent PGC-1α deacetylation. Trained ob/ob mice appear to have partially adapted to reduced mitochondrial biogenesis by AMPK/SIRT1/PGC-1

  15. Oxidized Low-Density Lipoprotein Contributes to Atherogenesis via Co-activation of Macrophages and Mast Cells

    PubMed Central

    Chen, Chong; Khismatullin, Damir B.

    2015-01-01

    Oxidized low-density lipoprotein (OxLDL) is a risk factor for atherosclerosis, due to its role in endothelial dysfunction and foam cell formation. Tissue-resident cells such as macrophages and mast cells release inflammatory mediators upon activation that in turn cause endothelial activation and monocyte adhesion. Two of these mediators are tumor necrosis factor (TNF)-α, produced by macrophages, and histamine, produced by mast cells. Static and microfluidic flow experiments were conducted to determine the number of adherent monocytes on vascular endothelium activated by supernatants of oxLDL-treated macrophages and mast cells or directly by oxLDL. The expression of adhesion molecules on activated endothelial cells and the concentration of TNF-α and histamine in the supernatants were measured by flow cytometry and enzyme-linked immunosorbent assay, respectively. A low dose of oxLDL (8 μg/ml), below the threshold for the clinical presentation of coronary artery disease, was sufficient to activate both macrophages and mast cells and synergistically increase monocyte-endothelium adhesion via released TNF-α and histamine. The direct exposure of endothelial cells to a much higher dose of oxLDL (80 μg/ml) had less effect on monocyte adhesion than the indirect activation via oxLDL-treated macrophages and mast cells. The results of this work indicate that the co-activation of macrophages and mast cells by oxLDL is an important mechanism for the endothelial dysfunction and atherogenesis. The observed synergistic effect suggests that both macrophages and mast cells play a significant role in early stages of atherosclerosis. Allergic patients with a lipid-rich diet may be at high risk for cardiovascular events due to high concentration of low-density lipoprotein and histamine in arterial vessel walls. PMID:25811595

  16. Multiple Mechanisms Cooperate to Constitutively Exclude the Transcriptional Co-Activator YAP from the Nucleus During Murine Oogenesis.

    PubMed

    Abbassi, Laleh; Malki, Safia; Cockburn, Katie; Macaulay, Angus; Robert, Claude; Rossant, Janet; Clarke, Hugh J

    2016-05-01

    Reproduction depends on the generation of healthy oocytes. Improving therapeutic strategies to prolong or rescue fertility depends on identifying the inter- and intracellular mechanisms that direct oocyte development under physiological conditions. Growth and proliferation of multiple cell types is regulated by the Hippo signaling pathway, whose chief effectors are the transcriptional co-activator YAP and its paralogue WWTR1. To resolve conflicting results concerning the potential role of Hippo in mammalian oocyte development, we systematically investigated the expression and localization of YAP in mouse oocytes. We report that that YAP is expressed in the germ cells beginning as early as Embryonic Day 15.5 and subsequently throughout pre- and postnatal oocyte development. However, YAP is restricted to the cytoplasm at all stages. YAP is phosphorylated at serine-112 in growing and fully grown oocytes, identifying a likely mechanistic basis for its nuclear exclusion, and becomes dephosphorylated at this site during meiotic maturation. Phosphorylation at serine-112 is regulated by a mechanism dependent on cyclic AMP and protein kinase A, which is known to be active in oocytes prior to maturation. Growing oocytes also contain a subpopulation of YAP, likely dephosphorylated, that is able enter the oocyte nucleus, but it is not retained there, implying that oocytes lack the cofactors required to retain YAP in the nucleus. Thus, although YAP is expressed throughout oocyte development, phosphorylation-dependent and -independent mechanisms cooperate to ensure that it does not accumulate in the nucleus. We conclude that nuclear YAP does not play a significant physiological role during oocyte development in mammals. PMID:26985001

  17. PGC-1-related coactivator (PRC) negatively regulates endothelial adhesion of monocytes via inhibition of NF κB activity

    SciTech Connect

    Chengye, Zhan; Daixing, Zhou Qiang, Zhong; Shusheng, Li

    2013-09-13

    Highlights: •First time to display that LPS downregulate the expression of PRC. •First time to show that PRC inhibits the induction of VCAM-1 and E-selectin. •First time to show that PRC inhibit monocytes attachment to endothelial cells. •First time to display that PRC inhibits transcriptional activity of NF-κB. •PRC protects the respiration rate and suppresses the glycolysis rate against LPS. -- Abstract: PGC-1-related coactivator (PRC) is a growth-regulated transcriptional cofactor known to activate many of the nuclear genes specifying mitochondrial respiratory function. Endothelial dysfunction is a prominent feature found in many inflammatory diseases. Adhesion molecules, such as VCAM-1, mediate the attachment of monocytes to endothelial cells, thereby playing an important role in endothelial inflammation. The effects of PRC in regards to endothelial inflammation remain unknown. In this study, our findings show that PRC can be inhibited by the inflammatory cytokine LPS in cultured human umbilical vein endothelial cells (HUVECs). In the presence of LPS, the expression of endothelial cell adhesion molecular, such as VCAM1 and E-selectin, is found to be increased. These effects can be negated by overexpression of PRC. Importantly, monocyte adhesion to endothelial cells caused by LPS is significantly attenuated by PRC. In addition, overexpression of PRC protects mitochondrial metabolic function and suppresses the rate of glycolysis against LPS. It is also found that overexpression of PRC decreases the transcriptional activity of NF-κB. These findings suggest that PRC is a negative regulator of endothelial inflammation.

  18. Cooperative activation of human papillomavirus type 8 gene expression by the E2 protein and the cellular coactivator p300.

    PubMed

    Müller, Andreas; Ritzkowsky, Andreas; Steger, Gertrud

    2002-11-01

    The E2 proteins of papillomaviruses (PV) bind to the coactivator CBP/p300 as do many other transcription factors, but the precise role of CBP/p300 in E2-specific functions is not yet understood. We show that the E2 protein of human PV type 8 (HPV8) directly binds to p300. Activation of HPV8 gene expression by low amounts of HPV8 E2 was stimulated up to sevenfold by coexpression of p300. The interaction between E2 and p300 may play a role in differentiation-dependent activation of PV gene expression, since we can show that the expression level of p300 increases during keratinocyte differentiation. Surprisingly, sequence-specific binding of E2 to its recognition sites within the regulatory region of HPV8 is not necessary for this cooperation, indicating that E2 can be recruited to the promoter via protein-protein interaction. HPV8 E2 binds via its N-terminal activation domain (AD), its C-terminal DNA binding domain (DBD), and its internal hinge region to p300 in vitro. Transient-transfection assays revealed that the AD is necessary and sufficient for cooperative activation with p300. However, we provide evidence that the interaction of the hinge and the DBD of HPV8 E2 with p300 may contribute. Our data suggest an important role of p300 in regulation of HPV8 gene expression and reveal a new mechanism by which E2 may be recruited to a promoter to activate transcription without sequence specific DNA binding. PMID:12368347

  19. The Play of Psychotherapy

    ERIC Educational Resources Information Center

    Marks-Tarlow, Terry

    2012-01-01

    The author reviews the role of play within psychotherapy. She does not discuss the formal play therapy especially popular for young children, nor play from the Jungian perspective that encourages the use of the sand tray with adults. Instead, she focuses on the informal use of play during psychotherapy as it is orchestrated intuitively. Because…

  20. Two people playing together: some thoughts on play, playing, and playfulness in psychoanalytic work.

    PubMed

    Vliegen, Nicole

    2009-01-01

    Children's play and the playfulness of adolescents and adults are important indicators of personal growth and development. When a child is not able to play, or an adolescent/adult is not able to be playful with thoughts and ideas, psychotherapy can help to find a more playful and creative stance. Elaborating Winnicott's (1968, p. 591) statement that "psychotherapy has to do with two people playing together," three perspectives on play in psychotherapy are discussed. In the first point of view, the child gets in touch with and can work through aspects of his or her inner world, while playing in the presence of the therapist. The power of play is then rooted in the playful communication with the self In a second perspective, in play the child is communicating aspects of his or her inner world to the therapist as a significant other. In a third view, in "playing together" child and therapist are coconstructing new meanings. These three perspectives on play are valid at different moments of a therapy process or for different children, depending on the complex vicissitudes of the child's constitution, life experiences, development, and psychic structure. Concerning these three perspectives, a parallel can be drawn between the therapist's attitude toward the child's play and the way the therapist responds to the verbal play of an adolescent or adult. We illustrate this with the case of Jacob, a late adolescent hardly able to play with ideas. PMID:20578437

  1. Child's Play: Therapist's Narrative

    PubMed Central

    Reddy, Rajakumari P.; Hirisave, Uma

    2014-01-01

    Play has been recognized as an essential component to children's healthy development. Schools of play therapy differ philosophically and technically, but they all embrace the therapeutic and developmental properties of play. This case report is an illustration of how a 6-year-old child with emotional disorder was facilitated to express concerns in child-centered play therapy. The paper discusses the therapist's narration of the child's play. PMID:24860228

  2. Play: early and eternal.

    PubMed Central

    Mears, C E; Harlow, H F

    1975-01-01

    A systematic 12-week investigation of development of play behavior was conducted with eight socially reared rhesus monkey infants. A new, basic and primary play form termed self-motion play or peragration was identified and examined. This behavior follows a human model which includes a wide range of pleasurable activities involving motion of the body through space, e.g., rocking, swinging, running, leaping, and water or snow skiing. It can be argued that self-motion play is the initial primate play form and because of its persistence constitutes a reinforcing agent for maintaining many complex patterns and even pastimes. Monkey self-motion play in the present study was divided into five separate patterns in order to compare the relative importance of social and individual peragration play, the role of apparatus and the overall developmental relationships between the different individual and social self-motion play patterns. The data showed that from 90 to 180 days of age self-motion play was independent of other forms of play, that individual self-motion play appeared earlier and with significantly greater increases in frequency than did social self-motion play, and that apparatus was a necessary component for significant increases in social self-motion play. Other findings were that self-motion play existed independent of locomotion and, though initiated by exploration, was separate from it. Therapeutic implications of self-motion play were discussed. Images PMID:1057178

  3. Functional interaction of nuclear receptor coactivator 4 with aryl hydrocarbon receptor

    SciTech Connect

    Kollara, Alexandra; Brown, Theodore J. . E-mail: brown@mshri.on.ca

    2006-07-28

    Aryl hydrocarbon receptor (AhR) transcriptional activity is enhanced by interaction with p160 coactivators. We demonstrate here that NcoA4, a nuclear receptor coactivator, interacts with and amplifies AhR action. NcoA4-AhR and NcoA4-ARNT interactions were demonstrated by immunoprecipitation in T47D breast cancer and COS cells and was independent of ligand. Overexpression of NcoA4 enhanced AhR transcriptional activity 3.2-fold in the presence of dioxin, whereas overexpression of a splice variant, NcoA4{beta}, as well as a variant lacking the C-terminal region enhanced AhR transcriptional activity by only 1.6-fold. Enhanced AhR signaling by NcoA4 was independent of the LXXLL and FXXLF motifs or of the activation domain. NcoA4 protein localized to cytoplasm in the absence of dioxin and in both the cytoplasm and nucleus following dioxin treatment. NcoA4-facilitation of AhR activity was abolished by overexpression of androgen receptor, suggesting a potential competition of AhR and androgen receptor for NcoA4. These findings thus demonstrate a functional interaction between NcoA4 and AhR that may alter AhR activity to affect disease development and progression.

  4. Expression of glucocorticoid receptor and coactivators in ependymal cells of male rats.

    PubMed

    Iwata, Kinuyo; Ozawa, Hitoshi

    2014-08-29

    Glucocorticoid receptor (GR) is a ligand-activated nuclear receptor which is widely distributed in the brain. Many types of neurons and glial cells are known to express GR, but the expression of GR in ependymal cells has yet to be identified. The present study therefore was undertaken to determine whether ependymal cells express GR and coactivators of GR, such as steroid receptor coactivator 1 (SRC-1) and p300. GR immunoreactivity was found in cells immunopositive to vimentin, a marker of ependymal cells, around the third ventricle (3V), the lateral ventricle (LV), the cerebral aqueduct and the fourth ventricle (4V), whereas the expression of GR in vimentin-immunoreactive (ir) cells was significantly reduced by adrenalectomy (ADX) in male rats. Vimentin-ir cells also expressed both SRC-1 and p300 at around 3V, LV, the cerebral aqueduct and 4V. ADX had no effect on the expression of SRC-1 or p300 in vimentin-ir cells. These results suggest that glucocorticoid may exert effects on ependymal cells through binding to GR followed by association with SRC-1 and p300 to maintain brain environment under stressful conditions. PMID:25392570

  5. The impact of language co-activation on L1 and L2 speech fluency.

    PubMed

    Bergmann, Christopher; Sprenger, Simone A; Schmid, Monika S

    2015-10-01

    Fluent speech depends on the availability of well-established linguistic knowledge and routines for speech planning and articulation. A lack of speech fluency in late second-language (L2) learners may point to a deficiency of these representations, due to incomplete acquisition. Experiments on bilingual language processing have shown, however, that there are strong reasons to believe that multilingual speakers experience co-activation of the languages they speak. We have studied to what degree language co-activation affects fluency in the speech of bilinguals, comparing a monolingual German control group with two bilingual groups: 1) first-language (L1) attriters, who have fully acquired German before emigrating to an L2 English environment, and 2) immersed L2 learners of German (L1: English). We have analysed the temporal fluency and the incidence of disfluency markers (pauses, repetitions and self-corrections) in spontaneous film retellings. Our findings show that learners to speak more slowly than controls and attriters. Also, on each count, the speech of at least one of the bilingual groups contains more disfluency markers than the retellings of the control group. Generally speaking, both bilingual groups-learners and attriters-are equally (dis)fluent and significantly more disfluent than the monolingual speakers. Given that the L1 attriters are unaffected by incomplete acquisition, we interpret these findings as evidence for language competition during speech production. PMID:26298087

  6. Transcriptional co-activator PGC-1 alpha drives the formation of slow-twitch muscle fibres.

    PubMed

    Lin, Jiandie; Wu, Hai; Tarr, Paul T; Zhang, Chen-Yu; Wu, Zhidan; Boss, Olivier; Michael, Laura F; Puigserver, Pere; Isotani, Eiji; Olson, Eric N; Lowell, Bradford B; Bassel-Duby, Rhonda; Spiegelman, Bruce M

    2002-08-15

    The biochemical basis for the regulation of fibre-type determination in skeletal muscle is not well understood. In addition to the expression of particular myofibrillar proteins, type I (slow-twitch) fibres are much higher in mitochondrial content and are more dependent on oxidative metabolism than type II (fast-twitch) fibres. We have previously identified a transcriptional co-activator, peroxisome-proliferator-activated receptor-gamma co-activator-1 (PGC-1 alpha), which is expressed in several tissues including brown fat and skeletal muscle, and that activates mitochondrial biogenesis and oxidative metabolism. We show here that PGC-1 alpha is expressed preferentially in muscle enriched in type I fibres. When PGC-1 alpha is expressed at physiological levels in transgenic mice driven by a muscle creatine kinase (MCK) promoter, a fibre type conversion is observed: muscles normally rich in type II fibres are redder and activate genes of mitochondrial oxidative metabolism. Notably, putative type II muscles from PGC-1 alpha transgenic mice also express proteins characteristic of type I fibres, such as troponin I (slow) and myoglobin, and show a much greater resistance to electrically stimulated fatigue. Using fibre-type-specific promoters, we show in cultured muscle cells that PGC-1 alpha activates transcription in cooperation with Mef2 proteins and serves as a target for calcineurin signalling, which has been implicated in slow fibre gene expression. These data indicate that PGC-1 alpha is a principal factor regulating muscle fibre type determination. PMID:12181572

  7. Reflexly evoked coactivation of cardiac vagal and sympathetic motor outflows: observations and functional implications.

    PubMed

    Paton, Julian F R; Nalivaiko, Eugene; Boscan, Pedro; Pickering, Anthony E

    2006-12-01

    1. The purpose of the present review is to highlight the pattern of activity in the parasympathetic and sympathetic nerves innervating the heart during their reflex activation. 2. We describe the well-known reciprocal control of cardiac vagal and sympathetic activity during the baroreceptor reflex, but point out that this appears to be the exception rather than the rule and that many other reflexes reviewed herein (e.g. peripheral chemoreceptor, nociceptor, diving response and oculocardiac) involve simultaneous coactivation of both autonomic limbs. 3. The heart rate response during simultaneous activation of cardiac autonomic outflows is unpredictable because it does not simply reflect the summation of opposing influences. Indeed, it can result in bradycardia (peripheral chemoreceptor, diving and corneal), tachycardia (nociceptor) and, in some circumstances, can predispose to malignant arrhythmias. 4. We propose that this cardiac autonomic coactivation may allow greater cardiac output during bradycardia (increased ventricular filling time and stronger contraction) than activation of the sympathetic limb alone. This may be important when pumping blood into a constricted vascular tree, such as is the case during the peripheral chemoreceptor reflex and the diving response. PMID:17184509

  8. The Ets factor Spi-B is a direct critical target of the coactivator OBF-1

    PubMed Central

    Bartholdy, Boris; Du Roure, Camille; Bordon, Alain; Emslie, Dianne; Corcoran, Lynn M.; Matthias, Patrick

    2006-01-01

    OBF-1 (Bob.1, OCA-B) is a lymphoid-specific transcriptional coactivator that associates with the transcription factors Oct-1 or Oct-2 on the conserved octamer element present in the promoters of several ubiquitous and lymphoid-specific genes. OBF-1-deficient mice have B cell-intrinsic defects, lack germinal centers, and have severely impaired immune responses to T cell-dependent antigens. Crucial genes that are regulated by OBF-1 and that might explain the observed phenotype of OBF-1 deficiency have remained elusive to date. Here we have generated transgenic mice expressing OBF-1 specifically in T cells and examined these together with mice lacking OBF-1 to discover transcriptional targets of this coactivator. Using microarray analysis, we have identified the Ets transcription factor Spi-B as a direct target gene critically regulated by OBF-1 that can help explain the phenotype of OBF-1-deficient mice. Spi-B has been implicated in signaling pathways downstream of the B cell receptor and is essential for germinal center formation and maintenance. The present findings establish a hierarchy between these two factors and provide a molecular link between OBF-1 and B cell receptor signaling. PMID:16861304

  9. The CREB coactivator CRTC2 controls hepatic lipid metabolism by regulating SREBP1.

    PubMed

    Han, Jinbo; Li, Erwei; Chen, Liqun; Zhang, Yuanyuan; Wei, Fangchao; Liu, Jieyuan; Deng, Haiteng; Wang, Yiguo

    2015-08-13

    Abnormal accumulation of triglycerides in the liver, caused in part by increased de novo lipogenesis, results in non-alcoholic fatty liver disease and insulin resistance. Sterol regulatory element-binding protein 1 (SREBP1), an important transcriptional regulator of lipogenesis, is synthesized as an inactive precursor that binds to the endoplasmic reticulum (ER). In response to insulin signalling, SREBP1 is transported from the ER to the Golgi in a COPII-dependent manner, processed by proteases in the Golgi, and then shuttled to the nucleus to induce lipogenic gene expression; however, the mechanisms underlying enhanced SREBP1 activity in insulin-resistant obesity and diabetes remain unclear. Here we show in mice that CREB regulated transcription coactivator 2 (CRTC2) functions as a mediator of mTOR signalling to modulate COPII-dependent SREBP1 processing. CRTC2 competes with Sec23A, a subunit of the COPII complex, to interact with Sec31A, another COPII subunit, thus disrupting SREBP1 transport. During feeding, mTOR phosphorylates CRTC2 and attenuates its inhibitory effect on COPII-dependent SREBP1 maturation. As hepatic overexpression of an mTOR-defective CRTC2 mutant in obese mice improved the lipogenic program and insulin sensitivity, these results demonstrate how the transcriptional coactivator CRTC2 regulates mTOR-mediated lipid homeostasis in the fed state and in obesity. PMID:26147081

  10. Coactivator SRC-2–dependent metabolic reprogramming mediates prostate cancer survival and metastasis

    PubMed Central

    Dasgupta, Subhamoy; Putluri, Nagireddy; Long, Weiwen; Zhang, Bin; Wang, Jianghua; Kaushik, Akash K.; Arnold, James M.; Bhowmik, Salil K.; Stashi, Erin; Brennan, Christine A.; Rajapakshe, Kimal; Coarfa, Cristian; Mitsiades, Nicholas; Ittmann, Michael M.; Chinnaiyan, Arul M.; Sreekumar, Arun; O’Malley, Bert W.

    2015-01-01

    Metabolic pathway reprogramming is a hallmark of cancer cell growth and survival and supports the anabolic and energetic demands of these rapidly dividing cells. The underlying regulators of the tumor metabolic program are not completely understood; however, these factors have potential as cancer therapy targets. Here, we determined that upregulation of the oncogenic transcriptional coregulator steroid receptor coactivator 2 (SRC-2), also known as NCOA2, drives glutamine-dependent de novo lipogenesis, which supports tumor cell survival and eventual metastasis. SRC-2 was highly elevated in a variety of tumors, especially in prostate cancer, in which SRC-2 was amplified and overexpressed in 37% of the metastatic tumors evaluated. In prostate cancer cells, SRC-2 stimulated reductive carboxylation of α-ketoglutarate to generate citrate via retrograde TCA cycling, promoting lipogenesis and reprogramming of glutamine metabolism. Glutamine-mediated nutrient signaling activated SRC-2 via mTORC1-dependent phosphorylation, which then triggered downstream transcriptional responses by coactivating SREBP-1, which subsequently enhanced lipogenic enzyme expression. Metabolic profiling of human prostate tumors identified a massive increase in the SRC-2–driven metabolic signature in metastatic tumors compared with that seen in localized tumors, further implicating SRC-2 as a prominent metabolic coordinator of cancer metastasis. Moreover, SRC-2 inhibition in murine models severely attenuated the survival, growth, and metastasis of prostate cancer. Together, these results suggest that the SRC-2 pathway has potential as a therapeutic target for prostate cancer. PMID:25664849

  11. Circadian Metabolic Regulation through Crosstalk between Casein Kinase 1δ and Transcriptional Coactivator PGC-1α

    PubMed Central

    Li, Siming; Chen, Xiao-Wei; Yu, Lei; Saltiel, Alan R.

    2011-01-01

    Circadian clock coordinates behavior and physiology in mammals in response to light and feeding cycles. Disruption of normal clock function is associated with increased risk for cardiovascular and metabolic diseases, underscoring the emerging concept that temporal regulation of tissue metabolism is a fundamental aspect of energy homeostasis. We have previously demonstrated that transcriptional coactivator, peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α), coordinates circadian metabolic rhythms through simultaneous regulation of metabolic and clock gene expression. In this study, we found that PGC-1α physically interacts with, and is phosphorylated by, casein kinase 1δ (CK1δ), a core component of the circadian pacemaker. CK1δ represses the transcriptional function of PGC-1α in cultured hepatocytes, resulting in decreased gluconeogenic gene expression and glucose secretion. At the molecular level, CK1δ phosphorylation of PGC-1α within its arginine/serine-rich domain enhances its degradation through the proteasome system. Together, these results elucidate a novel mechanism through which circadian pacemaker transduces timing signals to the metabolic regulatory network that controls hepatic energy metabolism. PMID:22052997

  12. Multiple functions and essential roles of nuclear receptor coactivators of bHLH-PAS family.

    PubMed

    Pecenova, L; Farkas, Robert

    2016-07-01

    Classical non-peptide hormones, such as steroids, retinoids, thyroid hormones, vitamin D3 and their derivatives including prostaglandins, benzoates, oxysterols, and bile acids, are collectively designated as small lipophilic ligands, acting via binding to the nuclear receptors (NRs). The NRs form a large superfamily of transcription factors that participate virtually in every key biological process. They control various aspects of animal development, fertility, gametogenesis, and numerous metabolic pathways, and can be misregulated in many types of cancers. Their enormous functional plasticity, as transcription factors, relates in part to NR-mediated interactions with plethora of coregulatory proteins upon ligand binding to their ligand binding domains (LBD), or following covalent modification. Here, we review some general views of a specific group of NR coregulators, so-called nuclear receptor coactivators (NRCs) or steroid receptor coactivators (SRCs) and highlight some of their unique functions/roles, which are less extensively mentioned and discussed in other reviews. We also try to pinpoint few neglected moments in the cooperative action of SRCs, which may also indicate their variable roles in the hormone-independent signaling pathways. PMID:27560800

  13. A Transcription Factor-Binding Domain of the Coactivator CBP Is Essential for Long-Term Memory and the Expression of Specific Target Genes

    ERIC Educational Resources Information Center

    Oliveira, Ana M. M.; Brindle, Paul K.; Abel, Ted; Wood, Marcelo A.; Attner, Michelle A.

    2006-01-01

    Transcriptional activation is a key process required for long-term memory formation. Recently, the transcriptional coactivator CREB-binding protein (CBP) was shown to be critical for hippocampus-dependent long-term memory and hippocampal synaptic plasticity. As a coactivator with intrinsic histone acetyltransferase activity, CBP interacts with…

  14. Learning through Role Play.

    ERIC Educational Resources Information Center

    Simmons, Sandra

    2001-01-01

    Explains how role playing can provide enriching experiences that develop children's literacy and numeracy skills. Lists key ingredients of good role playing and suggests ways to plan them and prepare space for them. (SK)

  15. Adlerian Play Therapy.

    ERIC Educational Resources Information Center

    Kottman, Terry; Warlick, Jayne

    1990-01-01

    Describes Adlerian method of play therapy. Claims Adlerian therapy represents an integration of the concepts and techniques of individual psychology into a method of using play to help troubled children. (Author/ABL)

  16. Role-Playing Mitosis.

    ERIC Educational Resources Information Center

    Wyn, Mark A.; Stegink, Steven J.

    2000-01-01

    Introduces a role playing activity that actively engages students in the learning process of mitosis. Students play either chromosomes carrying information, or cells in the cell membrane. (Contains 11 references.) (Author/YDS)

  17. Play, Policy & Practice.

    ERIC Educational Resources Information Center

    Klugman, Edgar, Ed.

    In 1992, the U.S.-Israel Binational Science Foundation (BSF), in conjunction with Wheelock College (Boston), sponsored its second workshop on children's play, entitled "Play and Cognitive Ability: The Cultural Context." This volume reflects the presentations and discussions held at the workshop, offering perspectives on children's play that, taken…

  18. The Pedagogy of Play

    ERIC Educational Resources Information Center

    Giesbrecht, Sheila

    2012-01-01

    Play is important. Environmental educators Sobel and Louv write about the relationship between children and outside play and suggest that early transcendental experiences within nature allow children to develop empathetic orientations towards the natural world. Children who play out-of-doors develop an appreciation for the environment and…

  19. Play Is the Way

    ERIC Educational Resources Information Center

    Gross, Steve; Sanderson, Rebecca Cornelli

    2012-01-01

    Historically, play has been viewed as a frivolous break from important endeavors like working and learning when, in fact, a child's ability to fully and freely engage in play is essential to their learning, productivity, and overall development. A natural drive to play is universal across all young mammals. Children from every society on earth…

  20. African oil plays

    SciTech Connect

    Clifford, A.J. )

    1989-09-01

    The vast continent of Africa hosts over eight sedimentary basins, covering approximately half its total area. Of these basins, only 82% have entered a mature exploration phase, 9% have had little or no exploration at all. Since oil was first discovered in Africa during the mid-1950s, old play concepts continue to bear fruit, for example in Egypt and Nigeria, while new play concepts promise to become more important, such as in Algeria, Angola, Chad, Egypt, Gabon, and Sudan. The most exciting developments of recent years in African oil exploration are: (1) the Gamba/Dentale play, onshore Gabon; (2) the Pinda play, offshore Angola; (3) the Lucula/Toca play, offshore Cabinda; (4) the Metlaoui play, offshore Libya/Tunisia; (5) the mid-Cretaceous sand play, Chad/Sudan; and (6) the TAG-I/F6 play, onshore Algeria. Examples of these plays are illustrated along with some of the more traditional oil plays. Where are the future oil plays likely to develop No doubt, the Saharan basins of Algeria and Libya will feature strongly, also the presalt of Equatorial West Africa, the Central African Rift System and, more speculatively, offshore Ethiopia and Namibia, and onshore Madagascar, Mozambique, and Tanzania.

  1. Mutation in the transcriptional coactivator EYA4 causes dilated cardiomyopathy and sensorineural hearing loss.

    PubMed

    Schönberger, Jost; Wang, Libin; Shin, Jordan T; Kim, Sang Do; Depreux, Frederic F S; Zhu, Hao; Zon, Leonard; Pizard, Anne; Kim, Jae B; Macrae, Calum A; Mungall, Andy J; Seidman, J G; Seidman, Christine E

    2005-04-01

    We identified a human mutation that causes dilated cardiomyopathy and heart failure preceded by sensorineural hearing loss (SNHL). Unlike previously described mutations causing dilated cardiomyopathy that affect structural proteins, this mutation deletes 4,846 bp of the human transcriptional coactivator gene EYA4. To elucidate the roles of eya4 in heart function, we studied zebrafish embryos injected with antisense morpholino oligonucleotides. Attenuated eya4 transcript levels produced morphologic and hemodynamic features of heart failure. To determine why previously described mutated EYA4 alleles cause SNHL without heart disease, we examined biochemical interactions of mutant Eya4 peptides. Eya4 peptides associated with SNHL, but not the shortened 193-amino acid peptide associated with dilated cardiomyopathy and SNHL, bound wild-type Eya4 and associated with Six proteins. These data define unrecognized and crucial roles for Eya4-Six-mediated transcriptional regulation in normal heart function. PMID:15735644

  2. Ablation of Coactivator Med1 Switches the Cell Fate of Dental Epithelia to That Generating Hair

    PubMed Central

    Nguyen, Thai; Sakai, Kiyoshi; He, Bing; Fong, Chak; Oda, Yuko

    2014-01-01

    Cell fates are determined by specific transcriptional programs. Here we provide evidence that the transcriptional coactivator, Mediator 1 (Med1), is essential for the cell fate determination of ectodermal epithelia. Conditional deletion of Med1 in vivo converted dental epithelia into epidermal epithelia, causing defects in enamel organ development while promoting hair formation in the incisors. We identified multiple processes by which hairs are generated in Med1 deficient incisors: 1) dental epithelial stem cells lacking Med 1 fail to commit to the dental lineage, 2) Sox2-expressing stem cells extend into the differentiation zone and remain multi-potent due to reduced Notch1 signaling, and 3) epidermal fate is induced by calcium as demonstrated in dental epithelial cell cultures. These results demonstrate that Med1 is a master regulator in adult stem cells to govern epithelial cell fate. PMID:24949995

  3. Genome Wide Binding Site Analysis Reveals Transcriptional Coactivation of Cytokinin-Responsive Genes by DELLA Proteins

    PubMed Central

    Marín-de la Rosa, Nora; Pfeiffer, Anne; Hill, Kristine; Locascio, Antonella; Bhalerao, Rishikesh P.; Miskolczi, Pal; Grønlund, Anne L.; Wanchoo-Kohli, Aakriti; Thomas, Stephen G.; Bennett, Malcolm J.; Lohmann, Jan U.; Blázquez, Miguel A.; Alabadí, David

    2015-01-01

    The ability of plants to provide a plastic response to environmental cues relies on the connectivity between signaling pathways. DELLA proteins act as hubs that relay environmental information to the multiple transcriptional circuits that control growth and development through physical interaction with transcription factors from different families. We have analyzed the presence of one DELLA protein at the Arabidopsis genome by chromatin immunoprecipitation coupled to large-scale sequencing and we find that it binds at the promoters of multiple genes. Enrichment analysis shows a strong preference for cis elements recognized by specific transcription factor families. In particular, we demonstrate that DELLA proteins are recruited by type-B ARABIDOPSIS RESPONSE REGULATORS (ARR) to the promoters of cytokinin-regulated genes, where they act as transcriptional co-activators. The biological relevance of this mechanism is underpinned by the necessity of simultaneous presence of DELLAs and ARRs to restrict root meristem growth and to promote photomorphogenesis. PMID:26134422

  4. Adr1 and Cat8 Mediate Coactivator Recruitment and Chromatin Remodeling at Glucose-Regulated Genes

    PubMed Central

    Biddick, Rhiannon K.; Law, G. Lynn; Young, Elton T.

    2008-01-01

    Background Adr1 and Cat8 co-regulate numerous glucose-repressed genes in S. cerevisiae, presenting a unique opportunity to explore their individual roles in coactivator recruitment, chromatin remodeling, and transcription. Methodology/Principal Findings We determined the individual contributions of Cat8 and Adr1 on the expression of a cohort of glucose-repressed genes and found three broad categories: genes that need both activators for full derepression, genes that rely mostly on Cat8 and genes that require only Adr1. Through combined expression and recruitment data, along with analysis of chromatin remodeling at two of these genes, ADH2 and FBP1, we clarified how these activators achieve this wide range of co-regulation. We find that Adr1 and Cat8 are not intrinsically different in their abilities to recruit coactivators but rather, promoter context appears to dictate which activator is responsible for recruitment to specific genes. These promoter-specific contributions are also apparent in the chromatin remodeling that accompanies derepression: ADH2 requires both Adr1 and Cat8, whereas, at FBP1, significant remodeling occurs with Cat8 alone. Although over-expression of Adr1 can compensate for loss of Cat8 at many genes in terms of both activation and chromatin remodeling, this over-expression cannot complement all of the cat8Δ phenotypes. Conclusions/Significance Thus, at many of the glucose-repressed genes, Cat8 and Adr1 appear to have interchangeable roles and promoter architecture may dictate the roles of these activators. PMID:18197247

  5. Thyroid Hormone Signaling In Vivo Requires a Balance between Coactivators and Corepressors

    PubMed Central

    Vella, Kristen R.; Ramadoss, Preeti; Costa-e-Sousa, Ricardo H.; Astapova, Inna; Ye, Felix D.; Holtz, Kaila A.; Harris, Jamie C.

    2014-01-01

    Resistance to thyroid hormone (RTH), a human syndrome, is characterized by high thyroid hormone (TH) and thyroid-stimulating hormone (TSH) levels. Mice with mutations in the thyroid hormone receptor beta (TRβ) gene that cannot bind steroid receptor coactivator 1 (SRC-1) and Src-1−/− mice both have phenotypes similar to that of RTH. Conversely, mice expressing a mutant nuclear corepressor 1 (Ncor1) allele that cannot interact with TRβ, termed NCoRΔID, have low TH levels and normal TSH. We hypothesized that Src-1−/− mice have RTH due to unopposed corepressor action. To test this, we crossed NCoRΔID and Src-1−/− mice to create mice deficient for coregulator action in all cell types. Remarkably, NCoRΔID/ΔID Src-1−/− mice have normal TH and TSH levels and are triiodothryonine (T3) sensitive at the level of the pituitary. Although absence of SRC-1 prevented T3 activation of key hepatic gene targets, NCoRΔID/ΔID Src-1−/− mice reacquired hepatic T3 sensitivity. Using in vivo chromatin immunoprecipitation assays (ChIP) for the related coactivator SRC-2, we found enhanced SRC-2 recruitment to TR-binding regions of genes in NCoRΔID/ΔID Src-1−/− mice, suggesting that SRC-2 is responsible for T3 sensitivity in the absence of NCoR1 and SRC-1. Thus, T3 targets require a critical balance between NCoR1 and SRC-1. Furthermore, replacement of NCoR1 with NCoRΔID corrects RTH in Src-1−/− mice through increased SRC-2 recruitment to T3 target genes. PMID:24550004

  6. Mediator subunit MED1 is a T3-dependent and T3-independent coactivator on the thyrotropin β gene promoter

    SciTech Connect

    Matsui, Keiji; Oda, Kasumi; Mizuta, Shumpei; Ishino, Ruri; Urahama, Norinaga; Hasegawa, Natsumi; Roeder, Robert G.; Ito, Mitsuhiro

    2013-10-11

    Highlights: •MED1 is a bona fide T3-dependent coactivator on TSHB promoter. •Mice with LxxLL-mutant MED1 have attenuated TSHβ mRNA and thyroid hormone levels. •MED1 activates TSHB promoter T3-dependently in cultured cells. •T3-dependent MED1 action is enhanced when SRC1/SRC2 or HDAC2 is downregulated. •MED1 is also a T3-independent GATA2/Pit1 coactivator on TSHB promoter. -- Abstract: The MED1 subunit of the Mediator transcriptional coregulator complex is a nuclear receptor-specific coactivator. A negative feedback mechanism of thyroid-stimulating hormone (TSH, or thyrotropin) expression in the thyrotroph in the presence of triiodothyronine (T3) is employed by liganded thyroid hormone receptor β (TRβ) on the TSHβ gene promoter, where conventional histone-modifying coactivators act as corepressors. We now provide evidence that MED1 is a ligand-dependent positive cofactor on this promoter. TSHβ gene transcription was attenuated in MED1 mutant mice in which the nuclear receptor-binding ability of MED1 was specifically disrupted. MED1 stimulated GATA2- and Pit1-mediated TSHβ gene promoter activity in a ligand-independent manner in cultured cells. MED1 also stimulated transcription from the TSHβ gene promoter in a T3-dependent manner. The transcription was further enhanced when the T3-dependent corepressors SRC1, SRC2, and HDAC2 were downregulated. Hence, MED1 is a T3-dependent and -independent coactivator on the TSHβ gene promoter.

  7. Coactivation of the PI3K/Akt and ERK signaling pathways in PCB153-induced NF-κB activation and caspase inhibition

    SciTech Connect

    Liu, Changjiang; Yang, Jixin; Fu, Wenjuan; Qi, Suqin; Wang, Chenmin; Quan, Chao; Yang, Kedi

    2014-06-15

    Polychlorinated biphenyls (PCBs) are a group of persistent and widely distributed environmental pollutants that have various deleterious effects, e.g., neurotoxicity, endocrine disruption and reproductive abnormalities. In order to verify the hypothesis that the PI3K/Akt and MAPK pathways play important roles in hepatotoxicity induced by PCBs, Sprague–Dawley (SD) rats were dosed with PCB153 intraperitoneally at 0, 4, 16 and 32 mg/kg for five consecutive days; BRL cells (rat liver cell line) were treated with PCB153 (0, 1, 5, and 10 μM) for 24 h. Results indicated that the PI3K/Akt and ERK pathways were activated in vivo and in vitro after exposure to PCB153, and protein levels of phospho-Akt and phospho-ERK were significantly increased. Nuclear factor-κB (NF-κB) activation and caspase-3, -8 and -9 inhibition caused by PCB153 were also observed. Inhibiting the ERK pathway significantly attenuated PCB153-induced NF-κB activation, whereas inhibiting the PI3K/Akt pathway hardly influenced phospho-NF-κB level. However, inhibiting the PI3K/Akt pathway significantly elevated caspase-3, -8 and -9 activities, while the ERK pathway only synergistically regulated caspase-9. Proliferating cell nuclear antigen (PCNA), a reliable indicator of cell proliferation, was also induced. Moreover, PCB153 led to hepatocellular hypertrophy and elevated liver weight. Taken together, PCB153 leads to aberrant proliferation and apoptosis of hepatocytes through NF-κB activation and caspase inhibition, and coactivated PI3K/Akt and ERK pathways play critical roles in PCB153-induced hepatotoxicity. - Highlights: • PCB153 led to hepatotoxicity through NF-κB activation and caspase inhibition. • The PI3K/Akt and ERK pathways were coactivated in vivo and in vitro by PCB153. • The ERK pathway regulated levels of phospho-NF-κB and caspase-9. • The PI3K/Akt pathway regulated levels of caspase-3, -8 and -9.

  8. Play and Digital Media

    ERIC Educational Resources Information Center

    Johnson, James E.; Christie, James F.

    2009-01-01

    This article examines how play is affected by computers and digital toys. Research indicates that when computer software targeted at children is problem-solving oriented and open-ended, children tend to engage in creative play and interact with peers in a positive manner. On the other hand, drill-and-practice programs can be quite boring and limit…

  9. Let's Just Play

    ERIC Educational Resources Information Center

    Schmidt, Janet

    2003-01-01

    Children have a right to play. The idea is so simple it seems self-evident. But a stroll through any toy superstore, or any half-hour of so-called "children's" programming on commercial TV, makes it clear that violence, not play, dominates what's being sold. In this article, the author discusses how teachers and parents share the responsibility in…

  10. Family Play Therapy.

    ERIC Educational Resources Information Center

    Ariel, Shlomo

    This paper examines a case study of family play therapy in Israel. The unique contributions of play therapy are evaluated including the therapy's accessibility to young children, its richness and flexibility, its exposure of covert patterns, its wealth of therapeutic means, and its therapeutic economy. The systematization of the therapy attempts…

  11. Clinical Intuition at Play

    ERIC Educational Resources Information Center

    Marks-Tarlow, Terry

    2014-01-01

    A clinical psychologist and consulting psychotherapist discusses how elements of play, inherent in the intuition required in analysis, can provide a cornerstone for serious therapeutic work. She argues that many aspects of play--its key roles in human development, individual growth, and personal creativity, among others--can help therapists and…

  12. Intergenerational Learning through Play.

    ERIC Educational Resources Information Center

    Davis, Lindsay; Larkin, Elizabeth; Graves, Stephen B.

    2002-01-01

    Argues that shared play experiences are a good way to build mutually beneficial relationships among older and younger generations. Outlines why intergenerational play is important, focusing on its cognitive, social, physical, and emotional benefits for both older adults and young children. Describes toys, materials, and games conducive to positive…

  13. Poetry and Play.

    ERIC Educational Resources Information Center

    Law, Richard A.

    Philosophers and poets from classical times to the present have argued that playful and amiable discourse are conducive to teaching and learning. The play principle enhances reading and study and should be applied by teachers to benefit their students. Teachers should help their students see that it is fun to enliven the imagination with good…

  14. The Fear of Play

    ERIC Educational Resources Information Center

    Almon, Joan

    2009-01-01

    Real play--play that is initiated and directed by children and that bubbles up from within the child rather than being imposed by adults--has largely disappeared from the landscape of childhood in the United States. There are many reasons for this, such as the long hours spent in front of screens each day or in activities organized by adults. In…

  15. Return to Play

    ERIC Educational Resources Information Center

    Mangan, Marianne

    2013-01-01

    Call it physical activity, call it games, or call it play. Whatever its name, it's a place we all need to return to. In the physical education, recreation, and dance professions, we need to redesign programs to address the need for and want of play that is inherent in all of us.

  16. Role Playing and Skits

    ERIC Educational Resources Information Center

    Letwin, Robert, Ed.

    1975-01-01

    Explores non-scripted role playing, dialogue role playing, sociodrama, and skits as variations of simulation techniques. Provides step-by-step guidelines for conducting such sessions. Successful Meetings, Bill Communications, Inc., 1422 Chestnut Street, Philadelphia, Pa. 19102. Subscription Rates: yearly (US, Canada, Mexico) $14.00; elsewhere,…

  17. Play as Experience

    ERIC Educational Resources Information Center

    Henricks, Thomas S.

    2015-01-01

    The author investigates what he believes one of the more important aspects of play--the experience it generates in its participants. He considers the quality of this experience in relation to five ways of viewing play--as action, interaction, activity, disposition, and within a context. He treats broadly the different forms of affect, including…

  18. Playing with Autistic Children.

    ERIC Educational Resources Information Center

    Casner, Mary W.; Marks, Susan F.

    The paper looks at the development of a play group for autistic children with descriptions of the autistic population, the daily program, the program's philosophy, the play group model, and actual lessons. Children, who ranged in age from 5 to 9 years, often chose activities which were self-stimulating and/or repetitive. The daily program included…

  19. Television at Play.

    ERIC Educational Resources Information Center

    Reid, Leonard N.; Frazer, Charles F.

    1980-01-01

    Discusses children as television viewers capable of manipulating the co-viewing setting by interpreting, constructing, and carrying out planned lines of play in relation to television and its content. Examples illustrate program-oriented and free-form improvisational play situations. (JMF)

  20. The Scottish Play.

    ERIC Educational Resources Information Center

    Wheat, Chris

    1999-01-01

    Recounts an episode when, as young schoolboys, Prince Charles and classmates presented "Macbeth" as an end-of-term-play. Traces the events at school that took on different meanings when viewed from maturity. (NH)

  1. The School Play

    ERIC Educational Resources Information Center

    Lathan, P. D.

    1977-01-01

    Offers a defense of the school play as a vastly underrated educational tool. Available from: Speech and Drama, Elizabeth Gradwell, Distribution Manager, The White Cottage, Allington, Chippenham, Wilts. (MH)

  2. Play Spaces in Denmark.

    ERIC Educational Resources Information Center

    Mitchell, Edna; Anderson, Robert T.

    1980-01-01

    Describes the variety of play spaces found in urban areas in Denmark: in banks, stores and individual businesses, neighborhood parks and small pocket playgrounds, specialized adventure and traffic playgrounds with supervised activities, and commercial amusement parks. (CM)

  3. Regulation of Brown and White Adipocyte Transcriptome by the Transcriptional Coactivator NT-PGC-1α

    PubMed Central

    Henagan, Tara M.; Shin, Jeho; Huypens, Peter; Newman, Susan; Gettys, Thomas W.

    2016-01-01

    The β3-adrenergic receptor (AR) signaling pathway is a major component of adaptive thermogenesis in brown and white adipose tissue during cold acclimation. The β3-AR signaling highly induces the expression of transcriptional coactivator PGC-1α and its splice variant N-terminal (NT)-PGC-1α, which in turn activate the transcription program of adaptive thermogenesis by co-activating a number of transcription factors. We previously reported that NT-PGC-1α is able to increase mitochondrial number and activity in cultured brown adipocytes by promoting the expression of mitochondrial and thermogenic genes. In the present study, we performed genome-wide profiling of NT-PGC-1α-responsive genes in brown adipocytes to identify genes potentially regulated by NT-PGC-1α. Canonical pathway analysis revealed that a number of genes upregulated by NT-PGC-1α are highly enriched in mitochondrial pathways including fatty acid transport and β-oxidation, TCA cycle and electron transport system, thus reinforcing the crucial role of NT-PGC-1α in the enhancement of mitochondrial function. Moreover, canonical pathway analysis of NT-PGC-1α-responsive genes identified several metabolic pathways including glycolysis and fatty acid synthesis. In order to validate the identified genes in vivo, we utilized the FL-PGC-1α-/- mouse that is deficient in full-length PGC-1α (FL-PGC-1α) but expresses a slightly shorter and functionally equivalent form of NT-PGC-1α (NT-PGC-1α254). The β3-AR-induced increase of NT-PGC-1α254 in FL-PGC-1α-/- brown and white adipose tissue was closely associated with elevated expression of genes involved in thermogenesis, mitochondrial oxidative metabolism, glycolysis and fatty acid synthesis. Increased adipose tissue thermogenesis by β3-AR activation resulted in attenuation of adipose tissue expansion in FL-PGC-1α-/- adipose tissue under the high-fat diet condition. Together, the data strengthen our previous findings that NT-PGC-1α regulates

  4. PGC-1α and PGC-1β Regulate Mitochondrial Density in Neurons*

    PubMed Central

    Wareski, Przemyslaw; Vaarmann, Annika; Choubey, Vinay; Safiulina, Dzhamilja; Liiv, Joanna; Kuum, Malle; Kaasik, Allen

    2009-01-01

    Recent studies indicate that regulation of cellular oxidative capacity through enhancing mitochondrial biogenesis may be beneficial for neuronal recovery and survival in human neurodegenerative disorders. The peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) has been shown to be a master regulator of mitochondrial biogenesis and cellular energy metabolism in muscle and liver. The aim of our study was to establish whether PGC-1α and PGC-1β control mitochondrial density also in neurons and if these coactivators could be up-regulated by deacetylation. The results demonstrate that PGC-1α and PGC-1β control mitochondrial capacity in an additive and independent manner. This effect was observed in all studied subtypes of neurons, in cortical, midbrain, and cerebellar granule neurons. We also observed that endogenous neuronal PGC-1α but not PGC-1β could be activated through its repressor domain by suppressing it. Results demonstrate also that overexpression of SIRT1 deacetylase or suppression of GCN5 acetyltransferase activates transcriptional activity of PGC-1α in neurons and increases mitochondrial density. These effects were mediated exclusively via PGC-1α, since overexpression of SIRT1 or suppression of GCN5 was ineffective where PGC-1α was suppressed by short hairpin RNA. Moreover, the results demonstrate that overexpression of PGC-1β or PGC-1α or activation of the latter by SIRT1 protected neurons from mutant α-synuclein- or mutant huntingtin-induced mitochondrial loss. These evidences demonstrate that activation or overexpression of the PGC-1 family of coactivators could be used to compensate for neuronal mitochondrial loss and suggest that therapeutic agents activating PGC-1 would be valuable for treating neurodegenerative diseases in which mitochondrial dysfunction and oxidative damage play an important pathogenic role. PMID:19542216

  5. Bifurcation analysis and potential landscapes of the p53-Mdm2 module regulated by the co-activator programmed cell death 5.

    PubMed

    Bi, Yuanhong; Yang, Zhuoqin; Zhuge, Changjing; Lei, Jinzhi

    2015-11-01

    The dynamics of p53 play important roles in the regulation of cell fate decisions in response to various stresses, and programmed cell death 5 (PDCD5) functions as a co-activator of p53 that modulates p53 dynamics. In the present paper, we investigated how p53 dynamics are modulated by PDCD5 during the deoxyribose nucleic acid damage response using methods of bifurcation analysis and potential landscape. Our results revealed that p53 activities display rich dynamics under different PDCD5 levels, including monostability, bistability with two stable steady states, oscillations, and the coexistence of a stable steady state (or two states) and an oscillatory state. The physical properties of the p53 oscillations were further demonstrated by the potential landscape in which the potential force attracts the system state to the limit cycle attractor, and the curl flux force drives coherent oscillation along the cyclic trajectory. We also investigated the efficiency with which PDCD5 induced p53 oscillations. We show that Hopf bifurcation can be induced by increasing the PDCD5 efficiency and that the system dynamics exhibited clear transition features in both barrier height and energy dissipation when the efficiency was close to the bifurcation point. PMID:26627563

  6. TIF1β functions as a coactivator for C/EBPβ and is required for induced differentiation in the myelomonocytic cell line U937

    PubMed Central

    Rooney, John W.; Calame, Kathryn L.

    2001-01-01

    Representational difference analysis (RDA) cloning has identified transcriptional intermediary factor 1 beta (TIF1β) as a gene inducibly expressed early during myeloid differentiation of the promyelocytic cell lines HL-60 and U937. To assess the role of TIF1β, U937 cell lines were made that expressed antisense-hammerhead ribozymes targeted specifically against TIF1β mRNA. These cells failed to differentiate into macrophages, as determined by several criteria: a nonadherent morphology, a failure to arrest cell cycle, lowered levels of macrophage-specific cell surface markers, resistance to Legionella pneumophila infection, a loss of the ability to phagocytose and chemotax, and decreased expression of chemokine mRNAs. One way TIF1β acts in macrophage differentiation is to augment C/EBPβ transcriptional activity. Furthermore, we show by EMSA supershifts and coimmunoprecipitation that C/EBPβ and TIF1β physically interact. Although TIF1β is necessary for macrophage differentiation of U937 cells, it is not sufficient, based on the inability of ectopically expressed TIF1β to induce or augment phorbol ester-induced macrophage differentiation. We conclude that TIF1β plays an important role in the terminal differentiation program of macrophages, which involves the coactivation of C/EBPβ and induction of C/EBPβ-responsive myeloid genes. PMID:11711437

  7. v-Myc inhibits C/EBPbeta activity by preventing C/EBPbeta-induced phosphorylation of the co-activator p300.

    PubMed

    Steinmann, S; Schulte, K; Beck, K; Chachra, S; Bujnicki, T; Klempnauer, K-H

    2009-07-01

    Myc, a key regulator of cellular proliferation, differentiation and apoptosis, exerts its biological functions by activating or suppressing the transcription of specific sets of target genes. C/EBP transcription factors play important roles during differentiation of various cell types and have been identified as critical targets for v-Myc- and c-Myc-dependent suppression of myeloid and fat cell differentiation. Here, we have addressed the mechanism by which v-Myc suppresses the activity of C/EBPbeta. We show that v-Myc is recruited to the aminoterminal domain of C/EBPbeta and interferes with the cooperation of C/EBPbeta and the co-activator p300 by preventing C/EBPbeta-induced phosphorylation of p300. We have identified the protein kinase responsible for C/EBPbeta-induced phosphorylation of p300 as homeo-domain interacting protein kinase 2 (HIPK2) and show that v-Myc displaces the kinase from the C/EBPbeta-p300 complex. Overall, our findings that the modulation of the C/EBPbeta-induced phosphorylation of p300 as a new mechanism of transcriptional suppression by v-Myc. PMID:19448669

  8. Bifurcation analysis and potential landscapes of the p53-Mdm2 module regulated by the co-activator programmed cell death 5

    NASA Astrophysics Data System (ADS)

    Bi, Yuanhong; Yang, Zhuoqin; Zhuge, Changjing; Lei, Jinzhi

    2015-11-01

    The dynamics of p53 play important roles in the regulation of cell fate decisions in response to various stresses, and programmed cell death 5 (PDCD5) functions as a co-activator of p53 that modulates p53 dynamics. In the present paper, we investigated how p53 dynamics are modulated by PDCD5 during the deoxyribose nucleic acid damage response using methods of bifurcation analysis and potential landscape. Our results revealed that p53 activities display rich dynamics under different PDCD5 levels, including monostability, bistability with two stable steady states, oscillations, and the coexistence of a stable steady state (or two states) and an oscillatory state. The physical properties of the p53 oscillations were further demonstrated by the potential landscape in which the potential force attracts the system state to the limit cycle attractor, and the curl flux force drives coherent oscillation along the cyclic trajectory. We also investigated the efficiency with which PDCD5 induced p53 oscillations. We show that Hopf bifurcation can be induced by increasing the PDCD5 efficiency and that the system dynamics exhibited clear transition features in both barrier height and energy dissipation when the efficiency was close to the bifurcation point.

  9. A role for peroxisome proliferator-activated receptor γ coactivator 1 (PGC-1) in the regulation of cardiac mitochondrial phospholipid biosynthesis.

    PubMed

    Lai, Ling; Wang, Miao; Martin, Ola J; Leone, Teresa C; Vega, Rick B; Han, Xianlin; Kelly, Daniel P

    2014-01-24

    The energy demands of the adult mammalian heart are met largely by ATP generated via oxidation of fatty acids in a high capacity mitochondrial system. Peroxisome proliferator-activated receptor γ coactivator 1 (PGC-1)-α and -β serve as inducible transcriptional coregulators of genes involved in mitochondrial biogenesis and metabolism. Whether PGC-1 plays a role in the regulation of mitochondrial structure is unknown. In this study, mice with combined deficiency of PGC-1α and PGC-1β (PGC-1αβ(-/-)) in adult heart were analyzed. PGC-1αβ(-/-) hearts exhibited a distinctive mitochondrial cristae-stacking abnormality suggestive of a phospholipid abnormality as has been described in humans with genetic defects in cardiolipin (CL) synthesis (Barth syndrome). A subset of molecular species, containing n-3 polyunsaturated species in the CL, phosphatidylcholine, and phosphatidylethanolamine profiles, was reduced in PGC-1αβ-deficient hearts. Gene expression profiling of PGC-1αβ(-/-) hearts revealed reduced expression of the gene encoding CDP-diacylglycerol synthase 1 (Cds1), an enzyme that catalyzes the proximal step in CL biosynthesis. Cds1 gene promoter-reporter cotransfection experiments and chromatin immunoprecipitation studies demonstrated that PGC-1α coregulates estrogen-related receptors to activate the transcription of the Cds1 gene. We conclude that the PGC-1/estrogen-related receptor axis coordinately regulates metabolic and membrane structural programs relevant to the maintenance of high capacity mitochondrial function in heart. PMID:24337569

  10. Multifunctional human transcriptional coactivator protein PC4 is a substrate of Aurora kinases and activates the Aurora enzymes.

    PubMed

    Dhanasekaran, Karthigeyan; Kumari, Sujata; Boopathi, Ramachandran; Shima, Hiroki; Swaminathan, Amrutha; Bachu, Mahesh; Ranga, Udaykumar; Igarashi, Kazuhiko; Kundu, Tapas K

    2016-03-01

    Positive coactivator 4 (PC4), a human transcriptional coactivator, is involved in diverse processes like chromatin organization and transcription regulation. It is hyperphosphorylated during mitosis, with unknown significance. For the first time, we demonstrate the function of PC4 outside the nucleus upon nuclear envelope breakdown. A fraction of PC4 associates with Aurora A and Aurora B and undergoes phosphorylation, following which PC4 activates both Aurora A and B to sustain optimal kinase activity to maintain the phosphorylation gradient for the proper functioning of the mitotic machinery. This mitotic role is evident in PC4 knockdown cells where the defects are rescued only by the catalytically active Aurora kinases, but not the kinase-dead mutants. Similarly, the PC4 phosphodeficient mutant failed to rescue such defects. Hence, our observations establish a novel mitotic function of PC4 that might be dependent on Aurora kinase-mediated phosphorylation. PMID:26777301

  11. Taiman acts as a coactivator of Yorkie in the Hippo pathway to promote tissue growth and intestinal regeneration

    PubMed Central

    Wang, Chao; Yin, Meng-Xin; Wu, Wei; Dong, Liang; Wang, Shimin; Lu, Yi; Xu, Jinjin; Wu, Wenqing; Li, Sheng; Zhao, Yun; Zhang, Lei

    2016-01-01

    The Hippo signaling pathway regulates tissue growth and organ size through controlling cell growth, proliferation and apoptosis. During these processes, the coactivator Yorkie partners with the transcription factor Scalloped to mediate Hippo pathway-regulated cellular functions. Here, we demonstrate that Taiman facilitates the activity of Yorkie. First, Taiman overexpression upregulates Hippo pathway-responsive genes and induces tissue overgrowth. Second, the loss of tai downregulates the expression of Hippo pathway target genes and reduces organ size as well as tissue overgrowth caused by Yorkie overexpression. Furthermore, we provide evidence that Taiman binds to Yorkie and facilitates the activity of Yorkie-Scalloped to activate the transcription of several Hippo pathway target genes. Moreover, we found that the C-terminus of Taiman is indispensable for the function of Taiman in Hippo signaling. Finally, we demonstrate that Taiman is also required in intestinal stem cell proliferation. Our findings suggest Taiman is an essential coactivator of Yorkie. PMID:27462453

  12. Atrogin-1 inhibits Akt-dependent cardiac hypertrophy in mice via ubiquitin-dependent coactivation of Forkhead proteins

    PubMed Central

    Li, Hui-Hua; Willis, Monte S.; Lockyer, Pamela; Miller, Nathaniel; McDonough, Holly; Glass, David J.; Patterson, Cam

    2007-01-01

    Cardiac hypertrophy is a major cause of human morbidity and mortality. Although much is known about the pathways that promote hypertrophic responses, mechanisms that antagonize these pathways have not been as clearly defined. Atrogin-1, also known as muscle atrophy F-box, is an F-box protein that inhibits pathologic cardiac hypertrophy by participating in a ubiquitin ligase complex that triggers degradation of calcineurin, a factor involved in promotion of pathologic hypertrophy. Here we demonstrated that atrogin-1 also disrupted Akt-dependent pathways responsible for physiologic cardiac hypertrophy. Our results indicate that atrogin-1 does not affect the activity of Akt itself, but serves as a coactivator for members of the Forkhead family of transcription factors that function downstream of Akt. This coactivator function of atrogin-1 was dependent on its ubiquitin ligase activity and the deposition of polyubiquitin chains on lysine 63 of Foxo1 and Foxo3a. Transgenic mice expressing atrogin-1 in the heart displayed increased Foxo1 ubiquitylation and upregulation of known Forkhead target genes concomitant with suppression of cardiac hypertrophy, while mice lacking atrogin-1 displayed the opposite physiologic phenotype. These experiments define a role for lysine 63–linked ubiquitin chains in transcriptional coactivation and demonstrate that atrogin-1 uses this mechanism to disrupt physiologic cardiac hypertrophic signaling through its effects on Forkhead transcription factors. PMID:17965779

  13. The Genomic Context and Corecruitment of SP1 Affect ERRα Coactivation by PGC-1α in Muscle Cells.

    PubMed

    Salatino, Silvia; Kupr, Barbara; Baresic, Mario; van Nimwegen, Erik; Handschin, Christoph

    2016-07-01

    The peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α) coordinates the transcriptional network response to promote an improved endurance capacity in skeletal muscle, eg, by coactivating the estrogen-related receptor-α (ERRα) in the regulation of oxidative substrate metabolism. Despite a close functional relationship, the interaction between these 2 proteins has not been studied on a genomic level. We now mapped the genome-wide binding of ERRα to DNA in a skeletal muscle cell line with elevated PGC-1α and linked the DNA recruitment to global PGC-1α target gene regulation. We found that, surprisingly, ERRα coactivation by PGC-1α is only observed in the minority of all PGC-1α recruitment sites. Nevertheless, a majority of PGC-1α target gene expression is dependent on ERRα. Intriguingly, the interaction between these 2 proteins is controlled by the genomic context of response elements, in particular the relative GC and CpG content, monomeric and dimeric repeat-binding site configuration for ERRα, and adjacent recruitment of the transcription factor specificity protein 1. These findings thus not only reveal a novel insight into the regulatory network underlying muscle cell plasticity but also strongly link the genomic context of DNA-response elements to control transcription factor-coregulator interactions. PMID:27182621

  14. Characterization of Novel Peroxisome Proliferator-activated Receptor γ Coactivator-1α (PGC-1α) Isoform in Human Liver*

    PubMed Central

    Felder, Thomas K.; Soyal, Selma M.; Oberkofler, Hannes; Hahne, Penelope; Auer, Simon; Weiss, Richard; Gadermaier, Gabriele; Miller, Karl; Krempler, Franz; Esterbauer, Harald; Patsch, Wolfgang

    2011-01-01

    Peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) is a transcriptional coactivator that contributes to the regulation of numerous transcriptional programs including the hepatic response to fasting. Mechanisms at transcriptional and post-transcriptional levels allow PGC-1α to support distinct biological pathways. Here we describe a novel human liver-specific PGC-1α transcript that results from alternative promoter usage and is induced by FOXO1 as well as glucocorticoids and cAMP-response element-binding protein signaling but is not present in other mammals. Hepatic tissue levels of novel and wild-type transcripts were similar but were only moderately associated (p < 0.003). Novel mRNA levels were associated with a polymorphism located in its promoter region, whereas wild-type transcript levels were not. Furthermore, hepatic PCK1 mRNA levels exhibited stronger associations with the novel than with the wild-type transcript levels. Except for a deletion of 127 amino acids at the N terminus, the protein, termed L-PGC-1α, is identical to PGC-1α. L-PGC-1α was localized in the nucleus and showed coactivation properties that overlap with those of PGC-1α. Collectively, our data support a role of L-PGC-1α in gluconeogenesis, but functional differences predicted from the altered structure suggest that L-PGC-1α may have arisen to adapt PGC-1α to more complex metabolic pathways in humans. PMID:22009745

  15. [RAC3 nuclear receptor co-activator has a protective role in the apoptosis induced by different stimuli].

    PubMed

    Coló, Georgina P; Rubio, María F; Alvarado, Cecilia V; Costas, Mónica A

    2007-01-01

    RAC3 belongs to the family of p160 nuclear receptors coactivators and it is over-expressed in several tumors. We have previously shown that RAC3 is a NF-kappaB coactivator. In this paper, we investigated the role of RAC3 in cell-sensitivity to apoptosis, using H2O2 in the human embryonic kidney cell line (HEK293), and tumor necrosis factor-related apoptosis inducing ligand (TRAIL) in a human chronic myeloid leukemia cell line (K562) naturally resistant to TRAIL. We observed that the tumoral K562 cells have high levels of RAC3 if compared with the non-tumoral HEK293 cells. The normal or transfected coactivator over-expression inhibits apoptosis through a diminished caspase activity and AIF nuclear translocation, increased NF-kappaB, AKT and p38, and decreased ERK activities. In contrast, inhibition of RAC3 by siRNA induced sensitivity of K562 to TRAIL-induced apoptosis. Such results suggest that over-expression of RAC3 contributes to tumor development through molecular mechanisms that do not depend strictly on acetylation and/or steroid hormones, which control cell death. This could be a possible target for future tumor therapies. PMID:18051230

  16. Training through gametherapy promotes coactivation of the pelvic floor and abdominal muscles in young women, nulliparous and continents

    PubMed Central

    Silva, Valeria Regina; Riccetto, Cássio; Martinho, Natalia Miguel; Marques, Joseane; Carvalho, Leonardo Cesar; Botelho, Simone

    2016-01-01

    ABSTRACT Introduction and objectives: Several studies have been investigated co-activation can enhance the effectveness of PFM training protocols allowing preventive and therapeutic goals in pelvic floor dysfunctions. The objective of the present study was to investigate if an abdominal-pelvic protocol of training (APT) using gametherapy would allow co-activation of PFM and transversus abdominis/oblique internal (TrA/OI) muscles. Patients and methods: Twenty-five nulliparous, continent, young females, with median age 24.76 (±3.76) years were evaluated using digital palpation (DP) of PFM and surface electromyography of PFM and TrA/OI simultaneously, during maximal voluntary contraction (MVC), alternating PFM and TrA/OI contraction requests. All women participated on a supervised program of APT using gametherapy, that included exercises of pelvic mobilization associated to contraction of TrA/OI muscles oriented by virtual games, for 30 minutes, three times a week, in a total of 10 sessions. Electromyographic data were processed and analyzed by ANOVA - analysis of variance. Results: When MVC of TrA/OI was solicited, it was observed simultaneous increase of electromyographic activity of PFM (p=0.001) following ATP. However, EMG activity did not change significantly during MVC of PFM. Conclusion: Training using gametherapy allowed better co-activation of pelvic floor muscles in response to contraction of TrA, in young nulliparous and continent women. PMID:27564290

  17. Remodeling the clock: coactivators and signal transduction in the circadian clockworks

    NASA Astrophysics Data System (ADS)

    Weber, Frank

    2009-03-01

    Most organisms on earth such as cyanobacteria, fungi, plants, insects, animals, and humans synchronize their physiological and behavioral activities with the environmental cycles of day and night. Significant progress has been made in unraveling the genetic components that constitute a molecular circadian clock, which facilitates the temporal control of physiology and behavior. Clock genes assemble interlocked transcriptional/translational feedback loops that underlie the circadian oscillations. Recent investigations revealed that posttranslational regulation of clock proteins is crucial for functioning of the molecular oscillator and for precise temporal control of circadian transcription. This review provides an overview of the homologous clockworks in Drosophila and mammals, with a special focus on recent insights in the posttranslational regulation of clock proteins as well as the role of coactivators, repressors, and signal transduction for circadian controlled genome-wide transcription. The emerging mechanisms of clock gene regulation provide an understanding of the temporal control of transcription in general and the circadian orchestration of physiology and behavior in particular.

  18. OncoBinder facilitates interpretation of proteomic interaction data by capturing coactivation pairs in cancer

    PubMed Central

    Zhang, Yao; Wang, Huanbin; Fang, Jing-Yuan; Xu, Jie

    2016-01-01

    High-throughput methods such as co-immunoprecipitationmass spectrometry (coIP-MS) and yeast 2 hybridization (Y2H) have suggested a broad range of unannotated protein-protein interactions (PPIs), and interpretation of these PPIs remains a challenging task. The advancements in cancer genomic researches allow for the inference of “coactivation pairs” in cancer, which may facilitate the identification of PPIs involved in cancer. Here we present OncoBinder as a tool for the assessment of proteomic interaction data based on the functional synergy of oncoproteins in cancer. This decision tree-based method combines gene mutation, copy number and mRNA expression information to infer the functional status of protein-coding genes. We applied OncoBinder to evaluate the potential binders of EGFR and ERK2 proteins based on the gastric cancer dataset of The Cancer Genome Atlas (TCGA). As a result, OncoBinder identified high confidence interactions (annotated by Kyoto Encyclopedia of Genes and Genomes (KEGG) or validated by low-throughput assays) more efficiently than co-expression based method. Taken together, our results suggest that evaluation of gene functional synergy in cancer may facilitate the interpretation of proteomic interaction data. The OncoBinder toolbox for Matlab is freely accessible online. PMID:26872056

  19. Architecture of the human XPC DNA repair and stem cell coactivator complex

    PubMed Central

    He, Yuan; Grob, Patricia; Fong, Yick W.; Nogales, Eva; Tjian, Robert

    2015-01-01

    The Xeroderma pigmentosum complementation group C (XPC) complex is a versatile factor involved in both nucleotide excision repair and transcriptional coactivation as a critical component of the NANOG, OCT4, and SOX2 pluripotency gene regulatory network. Here we present the structure of the human holo-XPC complex determined by single-particle electron microscopy to reveal a flexible, ear-shaped structure that undergoes localized loss of order upon DNA binding. We also determined the structure of the complete yeast homolog Rad4 holo-complex to find a similar overall architecture to the human complex, consistent with their shared DNA repair functions. Localized differences between these structures reflect an intriguing phylogenetic divergence in transcriptional capabilities that we present here. Having positioned the constituent subunits by tagging and deletion, we propose a model of key interaction interfaces that reveals the structural basis for this difference in functional conservation. Together, our findings establish a framework for understanding the structure-function relationships of the XPC complex in the interplay between transcription and DNA repair. PMID:26627236

  20. Structural Basis for the Recognition Between HIV-1 Integrase and Transcriptional Coactivator p75

    SciTech Connect

    Cherepanov,P.; Ambrosio, A.; Rahman, S.; Ellenberger, T.; Engelman, A.

    2005-01-01

    Integrase (IN) is an essential retroviral enzyme, and human transcriptional coactivator p75, which is also referred to as lens epithelium-derived growth factor (LEDGF), is the dominant cellular binding partner of HIV-1 IN. Here, we report the crystal structure of the dimeric catalytic core domain of HIV-1 IN complexed to the IN-binding domain of LEDGF. Previously identified LEDGF hotspot residues anchor the protein to both monomers at the IN dimer interface. The principal structural features of IN that are recognized by the host factor are the backbone conformation of residues 168-171 from one monomer and a hydrophobic patch that is primarily comprised of {alpha}-helices 1 and 3 of the second IN monomer. Inspection of diverse retroviral primary and secondary sequence elements helps to explain the apparent lentiviral tropism of the LEDGF-IN interaction. Because the lethal phenotypes of HIV-1 mutant viruses unable to interact with LEDGF indicate that IN function is highly sensitive to perturbations of the structure around the LEDGF-binding site, we propose that small molecule inhibitors of the protein-protein interaction might similarly disrupt HIV-1 replication.

  1. Leptin recruits Creb-regulated transcriptional coactivator 1 to improve hyperglycemia in insulin-deficient diabetes

    PubMed Central

    Kim, Geun Hyang; Szabo, Andras; King, Emily M.; Ayala, Jennifer; Ayala, Julio E.; Altarejos, Judith Y.

    2014-01-01

    Objective Leptin alleviates hyperglycemia in rodent models of Type 1 diabetes by activating leptin receptors within the central nervous system. Here we delineate whether non-canonical leptin signaling through the Creb-regulated transcriptional coactivator 1 (Crtc1) contributes to leptin-dependent improvements in diabetic glucose metabolism. Methods We employed mice with a targeted genetic disruption of Crtc1, tracer dilution techniques and neuroanatomical studies to interrogate whether Crtc1 enables leptin to improve glucose metabolism in streptozotocin-induced (STZ) diabetes. Results Here we show that leptin improves diabetic glucose metabolism through Crtc1-dependent and independent mechanisms. We find that leptin reduces diabetic hyperglycemia, hepatic gluconeogenic gene expression and selectively increases glucose disposal to brown adipose tissue and heart, in STZ-diabetic Crtc1WT mice but not Crtc1+/− mice. By contrast, leptin decreases circulating glucagon levels in both STZ-diabetic Crtc1WT and Crtc1+/− mice. We also demonstrate that leptin promotes Crtc1 nuclear translocation in pro-opiomelanocortin (Pomc) and non-Pomc neurons within the hypothalamic arcuate nucleus (ARC). Accordingly, leptin's ability to induce Pomc gene expression in the ARC is blunted in STZ-diabetic Crtc1+/− mice. Conclusions Our study reveals that Crtc1 functions as a conduit for leptin's glucoregulatory actions in insulin-dependent diabetes. This study also highlights a new role for Crtc1 in modulating peripheral glucose metabolism. PMID:25737949

  2. Skeletal muscle transcriptional coactivator PGC-1α mediates mitochondrial, but not metabolic, changes during calorie restriction

    PubMed Central

    Finley, Lydia W. S.; Lee, Jaewon; Souza, Amanda; Desquiret-Dumas, Valérie; Bullock, Kevin; Rowe, Glenn C.; Procaccio, Vincent; Clish, Clary B.; Arany, Zoltan; Haigis, Marcia C.

    2012-01-01

    Calorie restriction (CR) is a dietary intervention that extends lifespan and healthspan in a variety of organisms. CR improves mitochondrial energy production, fuel oxidation, and reactive oxygen species (ROS) scavenging in skeletal muscle and other tissues, and these processes are thought to be critical to the benefits of CR. PGC-1α is a transcriptional coactivator that regulates mitochondrial function and is induced by CR. Consequently, many of the mitochondrial and metabolic benefits of CR are attributed to increased PGC-1α activity. To test this model, we examined the metabolic and mitochondrial response to CR in mice lacking skeletal muscle PGC-1α (MKO). Surprisingly, MKO mice demonstrated a normal improvement in glucose homeostasis in response to CR, indicating that skeletal muscle PGC-1α is dispensable for the whole-body benefits of CR. In contrast, gene expression profiling and electron microscopy (EM) demonstrated that PGC-1α is required for the full CR-induced increases in mitochondrial gene expression and mitochondrial density in skeletal muscle. These results demonstrate that PGC-1α is a major regulator of the mitochondrial response to CR in skeletal muscle, but surprisingly show that neither PGC-1α nor mitochondrial biogenesis in skeletal muscle are required for the whole-body metabolic benefits of CR. PMID:22308395

  3. The transcriptional coactivator Bob1 promotes the development of follicular T helper cells via Bcl6.

    PubMed

    Stauss, Dennis; Brunner, Cornelia; Berberich-Siebelt, Friederike; Höpken, Uta E; Lipp, Martin; Müller, Gerd

    2016-04-15

    Follicular T helper (Tfh) cells are key regulators of the germinal center reaction and long-term humoral immunity. Tfh cell differentiation requires the sustained expression of the transcriptional repressor Bcl6; however, its regulation in CD4(+)T cells is incompletely understood. Here, we report that the transcriptional coactivator Bob1, encoded by thePou2af1gene, promotes Bcl6 expression and Tfh cell development. We found that Bob1 together with the octamer transcription factors Oct1/Oct2 can directly bind to and transactivate theBcl6andBtlapromoters. Mixed bone marrow chimeras revealed that Bob1 is required for the expression of normal levels of Bcl6 andBTLA, thereby controlling the pool size and composition of the Tfh compartment in a T cell-intrinsic manner. Our data indicate that T cell-expressed Bob1 is directly involved in Tfh cell differentiation and required for mounting normal T cell-dependent B-cell responses. PMID:26957522

  4. Yeast TFIID Serves as a Coactivator for Rap1p by Direct Protein-Protein Interaction▿

    PubMed Central

    Garbett, Krassimira A.; Tripathi, Manish K.; Cencki, Belgin; Layer, Justin H.; Weil, P. Anthony

    2007-01-01

    In vivo studies have previously shown that Saccharomyces cerevisiae ribosomal protein (RP) gene expression is controlled by the transcription factor repressor activator protein 1 (Rap1p) in a TFIID-dependent fashion. Here we have tested the hypothesis that yeast TFIID serves as a coactivator for RP gene transcription by directly interacting with Rap1p. We have found that purified recombinant Rap1p specifically interacts with purified TFIID in pull-down assays, and we have mapped the domains of Rap1p and subunits of TFIID responsible. In vitro transcription of a UASRAP1 enhancer-driven reporter gene requires both Rap1p and TFIID and is independent of the Fhl1p-Ifh1p coregulator. UASRAP1 enhancer-driven transactivation in extracts depleted of both Rap1p and TFIID is efficiently rescued by addition of physiological amounts of these two purified factors but not TATA-binding protein. We conclude that Rap1p and TFIID directly interact and that this interaction contributes importantly to RP gene transcription. PMID:17074814

  5. Simple arithmetic development in school age: The coactivation and selection of arithmetic facts.

    PubMed

    Megías, Patricia; Macizo, Pedro

    2015-10-01

    We evaluated the possible inhibitory mechanism responsible for selecting arithmetic facts in children from 8 or 9 years to 12 or 13 years of age. To this end, we used an adapted version of the negative priming paradigm (NP paradigm) in which children received additions and they decided whether they were correct or not. When an addition was incorrect but the result was that of multiplying the operands (e.g., 2 + 4 = 8), only children from 10 or 11 years of age onward took more time to respond compared with control additions with unrelated results, suggesting that they coactivated arithmetic knowledge of multiplications even when it was irrelevant to perform the task. Furthermore, children from 10 or 11 years of age onward were slower to respond when the result of multiplying the operands was presented again in a correct addition problem (e.g., 2 + 6 = 8). This result showed the development of an inhibitory mechanism involved in the selection of arithmetic facts through formal education. PMID:26037404

  6. Creb coactivators direct anabolic responses and enhance performance of skeletal muscle

    PubMed Central

    Bruno, Nelson E; Kelly, Kimberly A; Hawkins, Richard; Bramah-Lawani, Mariam; Amelio, Antonio L; Nwachukwu, Jerome C; Nettles, Kendall W; Conkright, Michael D

    2014-01-01

    During the stress response to intense exercise, the sympathetic nervous system (SNS) induces rapid catabolism of energy reserves through the release of catecholamines and subsequent activation of protein kinase A (PKA). Paradoxically, chronic administration of sympathomimetic drugs (β-agonists) leads to anabolic adaptations in skeletal muscle, suggesting that sympathetic outflow also regulates myofiber remodeling. Here, we show that β-agonists or catecholamines released during intense exercise induce Creb-mediated transcriptional programs through activation of its obligate coactivators Crtc2 and Crtc3. In contrast to the catabolic activity normally associated with SNS function, activation of the Crtc/Creb transcriptional complex by conditional overexpression of Crtc2 in the skeletal muscle of transgenic mice fostered an anabolic state of energy and protein balance. Crtc2-overexpressing mice have increased myofiber cross-sectional area, greater intramuscular triglycerides and glycogen content. Moreover, maximal exercise capacity was enhanced after induction of Crtc2 expression in transgenic mice. Collectively these findings demonstrate that the SNS-adrenergic signaling cascade coordinates a transient catabolic stress response during high-intensity exercise, which is followed by transcriptional reprogramming that directs anabolic changes for recovery and that augments subsequent exercise performance. PMID:24674967

  7. Sumoylation of the progesterone receptor and of the steroid receptor coactivator SRC-1.

    PubMed

    Chauchereau, Anne; Amazit, Larbi; Quesne, Monique; Guiochon-Mantel, Anne; Milgrom, Edwin

    2003-04-01

    SUMO-1 (small ubiquitin-like modifier) conjugation regulates the subcellular localization, stability, and activity of a variety of proteins. We show here that SUMO-1 overexpression markedly enhances progesterone receptor (PR)-mediated gene transcription. PR undergoes a sumoylation at lysine 388 located in its N-terminal domain. However, sumoylation of the receptor is not responsible for enhanced transcription because substitution of its target lysine did not abolish the effect of SUMO-1 and even converted the receptor into a slightly more active transactivator. Furthermore estrogen receptor alpha (ERalpha)-driven transcription is also enhanced by SUMO-1 overexpression contrasting with the absence of sumoylation of this receptor. We thus analyzed SUMO-1 conjugation to the steroid receptor coactivator SRC-1. We showed that this protein contains two major sites of conjugation at Lys-732 and Lys-774. Sumoylation was shown to increase PR-SRC-1 interaction and to prolong SRC-1 retention in the nucleus. It did not prevent SRC-1 ubiquitinylation and did not exert a clear effect on the stability of the protein. Overexpression of SUMO-1 enhanced PR-mediated gene transcription even in the presence of non-sumoylated mutants of SRC-1. This observation suggests that among the many protein partners involved in steroid hormone-mediated gene regulation several are probably targets of SUMO-1 modification. PMID:12529333

  8. Subcellular localization and mechanisms of nucleocytoplasmic trafficking of steroid receptor coactivator-1.

    PubMed

    Amazit, Larbi; Alj, Youssef; Tyagi, Rakesh Kumar; Chauchereau, Anne; Loosfelt, Hugues; Pichon, Christophe; Pantel, Jacques; Foulon-Guinchard, Emmanuelle; Leclerc, Philippe; Milgrom, Edwin; Guiochon-Mantel, Anne

    2003-08-22

    Steroid hormone receptors are ligand-stimulated transcription factors that modulate gene transcription by recruiting coregulators to gene promoters. Subcellular localization and dynamic movements of transcription factors have been shown to be one of the major means of regulating their transcriptional activity. In the present report we describe the subcellular localization and the dynamics of intracellular trafficking of steroid receptor coactivator 1 (SRC-1). After its synthesis in the cytoplasm, SRC-1 is imported into the nucleus, where it activates transcription and is subsequently exported back to the cytoplasm. In both the nucleus and cytoplasm, SRC-1 is localized in speckles. The characterization of SRC-1 nuclear localization sequence reveals that it is a classic bipartite signal localized in the N-terminal region of the protein, between amino acids 18 and 36. This sequence is highly conserved within the other members of the p160 family. Additionally, SRC-1 nuclear export is inhibited by leptomycin B. The region involved in its nuclear export is localized between amino acids 990 and 1038. It is an unusually large domain differing from the classic leucine-rich NES sequences. Thus SRC-1 nuclear export involves either an alternate type of NES or is dependent on the interaction of SRC-1 with a protein, which is exported through the crm1/exportin pathway. Overall, the intracellular trafficking of SRC-1 might be a mechanism to regulate the termination of hormone action, the interaction with other signaling pathways in the cytoplasm and its degradation. PMID:12791702

  9. Ligand induction of a transcriptionally active thyroid hormone receptor coactivator complex.

    PubMed Central

    Fondell, J D; Ge, H; Roeder, R G

    1996-01-01

    Transcriptional regulation by nuclear hormone receptors is thought to involve interactions with putative cofactors that may potentiate receptor function. Here we show that human thyroid hormone receptor alpha purified from HeLa cells grown in the presence of thyroid hormone (T3) is associated with a group of distinct nuclear proteins termed thyroid hormone receptor-associated proteins (TRAPs). In an in vitro system reconstituted with general initiation factors and cofactors (and in the absence of added T3), the "liganded" thyroid hormone receptor (TR)/TRAP complex markedly activates transcription from a promoter template containing T3-response elements. Moreover, whereas the retinoid X receptor is not detected in the TR/TRAP complex, its presence is required for the function of the complex. In contrast, human thyroid hormone receptor alpha purified from cells grown in the absence of T3 lacks the TRAPs and effects only a low level of activation that is dependent on added ligand. These findings demonstrate the ligand-dependent in vivo formation of a transcriptionally active TR-multisubunit protein complex and suggest a role for TRAPs as positive coactivators for gene-specific transcriptional activation. Images Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 PMID:8710870

  10. SIRT6 safeguards human mesenchymal stem cells from oxidative stress by coactivating NRF2

    PubMed Central

    Pan, Huize; Guan, Di; Liu, Xiaomeng; Li, Jingyi; Wang, Lixia; Wu, Jun; Zhou, Junzhi; Zhang, Weizhou; Ren, Ruotong; Zhang, Weiqi; Li, Ying; Yang, Jiping; Hao, Ying; Yuan, Tingting; Yuan, Guohong; Wang, Hu; Ju, Zhenyu; Mao, Zhiyong; Li, Jian; Qu, Jing; Tang, Fuchou; Liu, Guang-Hui

    2016-01-01

    SIRT6 belongs to the mammalian homologs of Sir2 histone NAD+-dependent deacylase family. In rodents, SIRT6 deficiency leads to aging-associated degeneration of mesodermal tissues. It remains unknown whether human SIRT6 has a direct role in maintaining the homeostasis of mesodermal tissues. To this end, we generated SIRT6 knockout human mesenchymal stem cells (hMSCs) by targeted gene editing. SIRT6-deficient hMSCs exhibited accelerated functional decay, a feature distinct from typical premature cellular senescence. Rather than compromised chromosomal stability, SIRT6-null hMSCs were predominately characterized by dysregulated redox metabolism and increased sensitivity to the oxidative stress. In addition, we found SIRT6 in a protein complex with both nuclear factor erythroid 2-related factor 2 (NRF2) and RNA polymerase II, which was required for the transactivation of NRF2-regulated antioxidant genes, including heme oxygenase 1 (HO-1). Overexpression of HO-1 in SIRT6-null hMSCs rescued premature cellular attrition. Our study uncovers a novel function of SIRT6 in maintaining hMSC homeostasis by serving as a NRF2 coactivator, which represents a new layer of regulation of oxidative stress-associated stem cell decay. PMID:26768768

  11. Regulation of Hepatic Triacylglycerol Metabolism by CGI-58 Does Not Require ATGL Co-activation.

    PubMed

    Lord, Caleb C; Ferguson, Daniel; Thomas, Gwynneth; Brown, Amanda L; Schugar, Rebecca C; Burrows, Amy; Gromovsky, Anthony D; Betters, Jenna; Neumann, Chase; Sacks, Jessica; Marshall, Stephanie; Watts, Russell; Schweiger, Martina; Lee, Richard G; Crooke, Rosanne M; Graham, Mark J; Lathia, Justin D; Sakaguchi, Takuya F; Lehner, Richard; Haemmerle, Guenter; Zechner, Rudolf; Brown, J Mark

    2016-07-26

    Adipose triglyceride lipase (ATGL) and comparative gene identification 58 (CGI-58) are critical regulators of triacylglycerol (TAG) turnover. CGI-58 is thought to regulate TAG mobilization by stimulating the enzymatic activity of ATGL. However, it is not known whether this coactivation function of CGI-58 occurs in vivo. Moreover, the phenotype of human CGI-58 mutations suggests ATGL-independent functions. Through direct comparison of mice with single or double deficiency of CGI-58 and ATGL, we show here that CGI-58 knockdown causes hepatic steatosis in both the presence and absence of ATGL. CGI-58 also regulates hepatic diacylglycerol (DAG) and inflammation in an ATGL-independent manner. Interestingly, ATGL deficiency, but not CGI-58 deficiency, results in suppression of the hepatic and adipose de novo lipogenic program. Collectively, these findings show that CGI-58 regulates hepatic neutral lipid storage and inflammation in the genetic absence of ATGL, demonstrating that mechanisms driving TAG lipolysis in hepatocytes differ significantly from those in adipocytes. PMID:27396333

  12. Interaction proteome of human Hippo signaling: modular control of the co-activator YAP1.

    PubMed

    Hauri, Simon; Wepf, Alexander; van Drogen, Audrey; Varjosalo, Markku; Tapon, Nic; Aebersold, Ruedi; Gstaiger, Matthias

    2013-01-01

    Tissue homeostasis is controlled by signaling systems that coordinate cell proliferation, cell growth and cell shape upon changes in the cellular environment. Deregulation of these processes is associated with human cancer and can occur at multiple levels of the underlying signaling systems. To gain an integrated view on signaling modules controlling tissue growth, we analyzed the interaction proteome of the human Hippo pathway, an established growth regulatory signaling system. The resulting high-resolution network model of 480 protein-protein interactions among 270 network components suggests participation of Hippo pathway components in three distinct modules that all converge on the transcriptional co-activator YAP1. One of the modules corresponds to the canonical Hippo kinase cassette whereas the other two both contain Hippo components in complexes with cell polarity proteins. Quantitative proteomic data suggests that complex formation with cell polarity proteins is dynamic and depends on the integrity of cell-cell contacts. Collectively, our systematic analysis greatly enhances our insights into the biochemical landscape underlying human Hippo signaling and emphasizes multifaceted roles of cell polarity complexes in Hippo-mediated tissue growth control. PMID:24366813

  13. [Proposal of a conceptual method of supportive care for co-active patients].

    PubMed

    Abidli, Yamine; Piette, Danielle; Casini, Annalisa

    2015-01-01

    There is a broad consensus on the importance for health professionals to support co-active patients. However, in practice, very few "patient care partnership" approaches have been developed. We hypothesized that the lack of investment in supporting patient care partnerships is due to the lack of interest in the skills needed by caregivers to provide such support. This paper intends to address thisgap. The patient care partnership method is studied, adapted and developed from existing models. It complements, harmonizes and integrates various schools of thought arising from the need to place the patient at the center of care and life in general. The patient care partnership method includes 7 stages during which the professional accompanies the patient through the process of care. The methodological approach for training professionals is designed to ensure that professionals experience the change as well as its difficulties of the change they expect from the patient in the care relationship. This method now needs to be validated by the experience of other professionals in order define the limits of application and to allow further development. PMID:26168615

  14. Rescue of Hippo coactivator YAP1 triggers DNA damage-induced apoptosis in hematological cancers.

    PubMed

    Cottini, Francesca; Hideshima, Teru; Xu, Chunxiao; Sattler, Martin; Dori, Martina; Agnelli, Luca; ten Hacken, Elisa; Bertilaccio, Maria Teresa; Antonini, Elena; Neri, Antonino; Ponzoni, Maurilio; Marcatti, Magda; Richardson, Paul G; Carrasco, Ruben; Kimmelman, Alec C; Wong, Kwok-Kin; Caligaris-Cappio, Federico; Blandino, Giovanni; Kuehl, W Michael; Anderson, Kenneth C; Tonon, Giovanni

    2014-06-01

    Oncogene-induced DNA damage elicits genomic instability in epithelial cancer cells, but apoptosis is blocked through inactivation of the tumor suppressor p53. In hematological cancers, the relevance of ongoing DNA damage and the mechanisms by which apoptosis is suppressed are largely unknown. We found pervasive DNA damage in hematologic malignancies, including multiple myeloma, lymphoma and leukemia, which leads to activation of a p53-independent, proapoptotic network centered on nuclear relocalization of ABL1 kinase. Although nuclear ABL1 triggers cell death through its interaction with the Hippo pathway coactivator YAP1 in normal cells, we show that low YAP1 levels prevent nuclear ABL1-induced apoptosis in these hematologic malignancies. YAP1 is under the control of a serine-threonine kinase, STK4. Notably, genetic inactivation of STK4 restores YAP1 levels, triggering cell death in vitro and in vivo. Our data therefore identify a new synthetic-lethal strategy to selectively target cancer cells presenting with endogenous DNA damage and low YAP1 levels. PMID:24813251

  15. Androgen Receptor Coactivator ARID4B Is Required for the Function of Sertoli Cells in Spermatogenesis.

    PubMed

    Wu, Ray-Chang; Zeng, Yang; Pan, I-Wen; Wu, Mei-Yi

    2015-09-01

    Defects in spermatogenesis, a process that produces spermatozoa inside seminiferous tubules of the testis, result in male infertility. Spermatogenic progression is highly dependent on a microenvironment provided by Sertoli cells, the only somatic cells and epithelium of seminiferous tubules. However, genes that regulate such an important activity of Sertoli cells are poorly understood. Here, we found that AT-rich interactive domain 4B (ARID4B), is essential for the function of Sertoli cells to regulate spermatogenesis. Specifically, we generated Sertoli cell-specific Arid4b knockout (Arid4bSCKO) mice, and showed that the Arid4bSCKO male mice were completely infertile with impaired testis development and significantly reduced testis size. Importantly, severe structural defects accompanied by loss of germ cells and Sertoli cell-only phenotype were found in many seminiferous tubules of the Arid4bSCKO testes. In addition, maturation of Sertoli cells was significantly delayed in the Arid4bSCKO mice, associated with delayed onset of spermatogenesis. Spermatogenic progression was also defective, showing an arrest at the round spermatid stage in the Arid4bSCKO testes. Interestingly, we showed that ARID4B functions as a "coactivator" of androgen receptor and is required for optimal transcriptional activation of reproductive homeobox 5, an androgen receptor target gene specifically expressed in Sertoli cells and critical for spermatogenesis. Together, our study identified ARID4B to be a key regulator of Sertoli cell function important for male germ cell development. PMID:26258622

  16. OncoBinder facilitates interpretation of proteomic interaction data by capturing coactivation pairs in cancer.

    PubMed

    Van Coillie, Samya; Liang, Lunxi; Zhang, Yao; Wang, Huanbin; Fang, Jing-Yuan; Xu, Jie

    2016-04-01

    High-throughput methods such as co-immunoprecipitationmass spectrometry (coIP-MS) and yeast 2 hybridization (Y2H) have suggested a broad range of unannotated protein-protein interactions (PPIs), and interpretation of these PPIs remains a challenging task. The advancements in cancer genomic researches allow for the inference of "coactivation pairs" in cancer, which may facilitate the identification of PPIs involved in cancer. Here we present OncoBinder as a tool for the assessment of proteomic interaction data based on the functional synergy of oncoproteins in cancer. This decision tree-based method combines gene mutation, copy number and mRNA expression information to infer the functional status of protein-coding genes. We applied OncoBinder to evaluate the potential binders of EGFR and ERK2 proteins based on the gastric cancer dataset of The Cancer Genome Atlas (TCGA). As a result, OncoBinder identified high confidence interactions (annotated by Kyoto Encyclopedia of Genes and Genomes (KEGG) or validated by low-throughput assays) more efficiently than co-expression based method. Taken together, our results suggest that evaluation of gene functional synergy in cancer may facilitate the interpretation of proteomic interaction data. The OncoBinder toolbox for Matlab is freely accessible online. PMID:26872056

  17. Prediction of Missing Flow Records Using Multilayer Perceptron and Coactive Neurofuzzy Inference System

    PubMed Central

    Tfwala, Samkele S.; Wang, Yu-Min; Lin, Yu-Chieh

    2013-01-01

    Hydrological data are often missing due to natural disasters, improper operation, limited equipment life, and other factors, which limit hydrological analysis. Therefore, missing data recovery is an essential process in hydrology. This paper investigates the accuracy of artificial neural networks (ANN) in estimating missing flow records. The purpose is to develop and apply neural networks models to estimate missing flow records in a station when data from adjacent stations is available. Multilayer perceptron neural networks model (MLP) and coactive neurofuzzy inference system model (CANFISM) are used to estimate daily flow records for Li-Lin station using daily flow data for the period 1997 to 2009 from three adjacent stations (Nan-Feng, Lao-Nung and San-Lin) in southern Taiwan. The performance of MLP is slightly better than CANFISM, having R2 of 0.98 and 0.97, respectively. We conclude that accurate estimations of missing flow records under the complex hydrological conditions of Taiwan could be attained by intelligent methods such as MLP and CANFISM. PMID:24453876

  18. Introducing Co-Activation Pattern Metrics to Quantify Spontaneous Brain Network Dynamics

    PubMed Central

    Chen, Jingyuan E.; Chang, Catie; Greicius, Michael D.; Glover, Gary H.

    2015-01-01

    Recently, fMRI researchers have begun to realize that the brain's intrinsic network patterns may undergo substantial changes during a single resting state (RS) scan. However, despite the growing interest in brain dynamics, metrics that can quantify the variability of network patterns are still quite limited. Here, we first introduce various quantification metrics based on the extension of co-activation pattern (CAP) analysis, a recently proposed point-process analysis that tracks state alternations at each individual time frame and relies on very few assumptions; then apply these proposed metrics to quantify changes of brain dynamics during a sustained 2-back working memory (WM) task compared to rest. We focus on the functional connectivity of two prominent RS networks, the default-mode network (DMN) and executive control network (ECN). We first demonstrate less variability of global Pearson correlations with respect to the two chosen networks using a sliding-window approach during WM task compared to rest; then we show that the macroscopic decrease in variations in correlations during a WM task is also well characterized by the combined effect of a reduced number of dominant CAPs, increased spatial consistency across CAPs, and increased fractional contributions of a few dominant CAPs. These CAP metrics may provide alternative and more straightforward quantitative means of characterizing brain network dynamics than time-windowed correlation analyses. PMID:25662866

  19. Architecture of the human XPC DNA repair and stem cell coactivator complex.

    PubMed

    Zhang, Elisa T; He, Yuan; Grob, Patricia; Fong, Yick W; Nogales, Eva; Tjian, Robert

    2015-12-01

    The Xeroderma pigmentosum complementation group C (XPC) complex is a versatile factor involved in both nucleotide excision repair and transcriptional coactivation as a critical component of the NANOG, OCT4, and SOX2 pluripotency gene regulatory network. Here we present the structure of the human holo-XPC complex determined by single-particle electron microscopy to reveal a flexible, ear-shaped structure that undergoes localized loss of order upon DNA binding. We also determined the structure of the complete yeast homolog Rad4 holo-complex to find a similar overall architecture to the human complex, consistent with their shared DNA repair functions. Localized differences between these structures reflect an intriguing phylogenetic divergence in transcriptional capabilities that we present here. Having positioned the constituent subunits by tagging and deletion, we propose a model of key interaction interfaces that reveals the structural basis for this difference in functional conservation. Together, our findings establish a framework for understanding the structure-function relationships of the XPC complex in the interplay between transcription and DNA repair. PMID:26627236

  20. The TIP60 Complex Is a Conserved Coactivator of HIF1A.

    PubMed

    Perez-Perri, Joel I; Dengler, Veronica L; Audetat, K Audrey; Pandey, Ahwan; Bonner, Elizabeth A; Urh, Marjeta; Mendez, Jacqui; Daniels, Danette L; Wappner, Pablo; Galbraith, Matthew D; Espinosa, Joaquín M

    2016-06-28

    Hypoxia-inducible factors (HIFs) are critical regulators of the cellular response to hypoxia. Despite their established roles in normal physiology and numerous pathologies, the molecular mechanisms by which they control gene expression remain poorly understood. We report here a conserved role for the TIP60 complex as a HIF1 transcriptional cofactor in Drosophila and human cells. TIP60 (KAT5) is required for HIF1-dependent gene expression in fly cells and embryos and colorectal cancer cells. HIF1A interacts with and recruits TIP60 to chromatin. TIP60 is dispensable for HIF1A association with its target genes but is required for HIF1A-dependent chromatin modification and RNA polymerase II activation in hypoxia. In human cells, global analysis of HIF1A-dependent gene activity reveals that most HIF1A targets require either TIP60, the CDK8-Mediator complex, or both as coactivators for full expression in hypoxia. Thus, HIF1A employs functionally diverse cofactors to regulate different subsets of genes within its transcriptional program. PMID:27320910

  1. Metastatic progression with resistance to aromatase inhibitors is driven by the steroid receptor coactivator SRC-1.

    PubMed

    McBryan, Jean; Theissen, Sarah M; Byrne, Christopher; Hughes, Eamon; Cocchiglia, Sinead; Sande, Stephen; O'Hara, Jane; Tibbitts, Paul; Hill, Arnold D K; Young, Leonie S

    2012-01-15

    Aromatase inhibitors (AI) are a standard-of-care treatment for postmenopausal, estrogen receptor-positive breast cancers. Although tumor recurrence on AI therapy occurs, the mechanisms underlying acquired resistance to AIs remain unknown. In this study, we examined a cohort of endocrine-treated breast cancer patients and used a cell line model of resistance to the AI letrozole. In patients treated with a first-line AI, hormone receptor switching between primary and resistant tumors was a common feature of disease recurrence. Resistant cells exhibited a switch from steroid-responsive growth to growth factor-responsive and endocrine-independent growth, which was accompanied by the development of a more migratory and disorganized phenotype. Both the resistant cells and tumors from AI-resistant patients showed high expression of the steroid receptor coactivator SRC-1. Direct interactions between SRC-1 and the transcription factor Ets2 regulated Myc and MMP9. SRC-1 was required for the aggressive and motile phenotype of AI-resistant cells. Interestingly, SRC-1 expression in primary and/or recurrent tumors was associated with a reduction in disease-free survival in treated patients. Moreover, there was a significant association between SRC-1 and Ets2 in the recurrent tissue compared with the matched primary tumor. Together, our findings elucidate a mechanism of AI-specific metastatic progression in which interactions between SRC-1 and Ets2 promote dedifferentiation and migration in hormone-dependent breast cancer. PMID:22108824

  2. Playing It Safe.

    ERIC Educational Resources Information Center

    O'Neill, Steve

    2000-01-01

    Provides tips on how to avoid accidents and injuries on school playgrounds. Tips include removing of old, dangerous equipment; relocating play areas to safer ground; choosing the right surface; factoring in long-term costs for replenishing and redistributing loose materials; and considering Americans with Disabilities Act issues. (GR)

  3. Predicting elections: child's play!

    PubMed

    Antonakis, John; Dalgas, Olaf

    2009-02-27

    In two experiments, children and adults rated pairs of faces from election races. Naïve adults judged a pair on competence; after playing a game, children chose who they would prefer to be captain of their boat. Children's (as well as adults') preferences accurately predicted actual election outcomes. PMID:19251621

  4. Want to Play Geometry?

    ERIC Educational Resources Information Center

    Kaufmann, Matthew L.; Bomer, Megan A.; Powell, Nancy Norem

    2009-01-01

    Students enter the geometry classroom with a strong concept of fairness and a sense of what it means to "play by the rules," yet many students have difficulty understanding the postulates, or rules, of geometry and their implications. Although they may never have articulated the properties of an axiomatic system, they have gained a practical…

  5. Statistics at Play

    ERIC Educational Resources Information Center

    English, Lyn D.

    2014-01-01

    An exciting event had occurred for the grade 3 classes at Woodlands State School. A new play space designated for the older grades had now been opened to the third graders. In sharing their excitement over this "real treat, real privilege," the teachers invited the children to find out more about playgrounds and, in particular, their new…

  6. "Playing" with Science

    ERIC Educational Resources Information Center

    Allen, Dave

    2012-01-01

    When faced with a multitude of tasks, any opportunity to "kill two birds with one stone" is welcome. Drama has always excited the author: as a child performing in plays, later as a student and now as a teacher directing performances and improvising within lessons. The author was lucky enough to have inspirational teachers during his primary and…

  7. Abstraction through Game Play

    ERIC Educational Resources Information Center

    Avraamidou, Antri; Monaghan, John; Walker, Aisha

    2012-01-01

    This paper examines the computer game play of an 11-year-old boy. In the course of building a virtual house he developed and used, without assistance, an artefact and an accompanying strategy to ensure that his house was symmetric. We argue that the creation and use of this artefact-strategy is a mathematical abstraction. The discussion…

  8. Who's Calling the Plays?

    ERIC Educational Resources Information Center

    Goldman, Jay P.

    1990-01-01

    Without an enforceable policy, school athletics programs are beset by politics, high finance, and public sentiment. The most nettlesome problems include loss of instructional time to sports and extracurricular activities; the appropriateness and effectiveness of no-pass/no-play rules; lack of sportsmanship; proliferation of interstate competition;…

  9. Playing with danger.

    PubMed

    Pearce, Lynne

    Young people who sit still for hours playing computer games can double their risk of potentially fatal blood clots. The charity Lifeblood is alerting nurses to 'e-thrombosis'. It is calling on them to ensure young people are aware of the risks of prolonged immobility and the need to take regular breaks from gaming or using a computer. PMID:23061127

  10. The Games Children Play

    ERIC Educational Resources Information Center

    Padak, Nancy; Rasinski, Timothy

    2008-01-01

    The games that children play are not just for fun-they often lead to important skill development. Likewise, word games are fun opportunities for parents and children to spend time together and for children to learn a lot about sounds and words. In this Family Involvement column, the authors describe 12 easy-to-implement word games that parents and…

  11. One Play a Day

    ERIC Educational Resources Information Center

    Blankenship, Mark

    2007-01-01

    Undergraduate theater students rarely get the chance to work on a major world premiere, but this year hundreds of them will. Currently, more than 70 colleges and universities are participating in "365 Days/365 Plays," an ambitious project from Pulitzer Prize-winning playwright Suzan-Lori Parks. Every week, as they mount their portion of this epic…

  12. Play's Importance in School

    ERIC Educational Resources Information Center

    Sandberg, Anette; Heden, Rebecca

    2011-01-01

    The purpose of this study is to contribute knowledge on and gain an understanding of elementary school teachers' perspectives on the function of play in children's learning processes. The study is qualitative with a hermeneutical approach and has George Herbert Mead as a theoretical frame of reference. Interviews have been carried out with seven…

  13. Playing It Safe.

    ERIC Educational Resources Information Center

    Jones, Rebecca

    1997-01-01

    Offers tips for avoiding sports-related injuries: (1) expect more of coaches; (2) develop an athletic-safety plan; (3) consider hiring an athletic trainer; (4) check facilities and equipment regularly; (5) recognize athletes' limitations; (6) take precautions beyond the playing field; and (7) check liability coverage and obtain informed consent.…

  14. Integrated Play Groups

    ERIC Educational Resources Information Center

    Glovak, Sandra

    2007-01-01

    As an occupational therapist running social play groups with sensory integration for children on the autism spectrum, the author frequently doubted the wisdom of combining several children on the spectrum into a group. In fact, as the owner of a clinic she said, "No more!" The groups seemed like a waste of parents' time and money, and she refused…

  15. CREB-regulated transcription coactivator 1 enhances CREB-dependent gene expression in spinal cord to maintain the bone cancer pain in mice

    PubMed Central

    Liang, Ying; Liu, Yue; Hou, Bailing; Zhang, Wei; Liu, Ming; Sun, Yu-E; Gu, Xiaoping

    2016-01-01

    Background cAMP response element binding protein (CREB)-dependent gene expression plays an important role in central sensitization. CREB-regulated transcription coactivator 1 (CRTC1) dramatically increases CREB-mediated transcriptional activity. Brain-derived neurotrophic factor, N-methyl-d-aspartate receptor subunit 2B, and miRNA-212/132, which are highly CREB responsive, function downstream from CREB/CRTC1 to mediate activity-dependent synaptic plasticity and in turn loops back to amplify CREB/CRTC1 signaling. This study aimed to investigate the role of spinal CRTC1 in the maintenance of bone cancer pain using an RNA interference method. Results Osteosarcoma cells were implanted into the intramedullary space of the right femurs of C3H/HeNCrlVr mice to induce bone cancer pain. Western blotting was applied to examine the expression of spinal phospho-Ser133 CREB and CRTC1. We further investigated effects of repeated intrathecal administration with Adenoviruses expressing CRTC1-small interfering RNA (siRNA) on nociceptive behaviors and on the upregulation of CREB/CRTC1-target genes associated with bone cancer pain. Inoculation of osteosarcoma cells induced progressive mechanical allodynia and spontaneous pain, and resulted in upregulation of spinal p-CREB and CRTC1. Repeated intrathecal administration with Adenoviruses expressing CRTC1-siRNA attenuated bone cancer–evoked pain behaviors, and reduced CREB/CRTC1-target genes expression in spinal cord, including BDNF, NR2B, and miR-212/132. Conclusions Upregulation of CRTC1 enhancing CREB-dependent gene transcription in spinal cord may play an important role in bone cancer pain. Inhibition of spinal CRTC1 expression reduced bone cancer pain. Interruption to the positive feedback circuit between CREB/CRTC1 and its targets may contribute to the analgesic effects. These findings may provide further insight into the mechanisms and treatment of bone cancer pain. PMID:27060162

  16. Canada's east coast play

    SciTech Connect

    Doig, I.M.

    1984-02-01

    The intent of this paper is to give a basic overview presentation on Canada's east coast play - most likely the number one offshore play in the free world - and possibly the world. The play stretches 2,500 miles north and south, as it follows the Labrador Coast, past the Strait of Belle Isle and onto the Grand Banks of Newfoundland and as it makes a 90 degree turn, 1,000 miles east to west along the coast of Nova Scotia to the Georges Bank. 3,500 miles in all - which if placed in western Canada, would stretch from northern Alberta to southern Mexico. It's geologic potential is immense - 15-20 billion barrels of oil and 80-90 Tcf of natural gas. And so far only approximately 2 billion barrels of oil and 5 Tcf of natural gas have been found. There is more out there. And less than 200 wells have been drilled - still very virgin territory. Two world size discoveries have been made in the area. Hibernia, on the Grand Banks, is estimated to contain 1.8 billion barrels. Venture, on the Scotian Shelf, has a natural gas reserve of 2.5 Tcf - big by Canadian standards and significant in that Mobil Oil has also made some other interesting discoveries on the same Sable Island block which have not been delineated.

  17. Autoimmune regulator is acetylated by transcription coactivator CBP/p300

    SciTech Connect

    Saare, Mario; Rebane, Ana; Rajashekar, Balaji; Vilo, Jaak; Peterson, Paert

    2012-08-15

    The Autoimmune Regulator (AIRE) is a regulator of transcription in the thymic medulla, where it controls the expression of a large set of peripheral-tissue specific genes. AIRE interacts with the transcriptional coactivator and acetyltransferase CBP and synergistically cooperates with it in transcriptional activation. Here, we aimed to study a possible role of AIRE acetylation in the modulation of its activity. We found that AIRE is acetylated in tissue culture cells and this acetylation is enhanced by overexpression of CBP and the CBP paralog p300. The acetylated lysines were located within nuclear localization signal and SAND domain. AIRE with mutations that mimicked acetylated K243 and K253 in the SAND domain had reduced transactivation activity and accumulated into fewer and larger nuclear bodies, whereas mutations that mimicked the unacetylated lysines were functionally similar to wild-type AIRE. Analogously to CBP, p300 localized to AIRE-containing nuclear bodies, however, the overexpression of p300 did not enhance the transcriptional activation of AIRE-regulated genes. Further studies showed that overexpression of p300 stabilized the AIRE protein. Interestingly, gene expression profiling revealed that AIRE, with mutations mimicking K243/K253 acetylation in SAND, was able to activate gene expression, although the affected genes were different and the activation level was lower from those regulated by wild-type AIRE. Our results suggest that the AIRE acetylation can influence the selection of AIRE activated genes. -- Highlights: Black-Right-Pointing-Pointer AIRE is acetylated by the acetyltransferases p300 and CBP. Black-Right-Pointing-Pointer Acetylation occurs between CARD and SAND domains and within the SAND domain. Black-Right-Pointing-Pointer Acetylation increases the size of AIRE nuclear dots. Black-Right-Pointing-Pointer Acetylation increases AIRE protein stability. Black-Right-Pointing-Pointer AIRE acetylation mimic regulates a different set of AIRE

  18. GATA2 facilitates steroid receptor coactivator recruitment to the androgen receptor complex

    PubMed Central

    He, Bin; Lanz, Rainer B.; Fiskus, Warren; Geng, Chuandong; Yi, Ping; Hartig, Sean M.; Rajapakshe, Kimal; Shou, John; Wei, Liping; Shah, Shrijal S.; Foley, Christopher; Chew, Sue Anne; Eedunuri, Vijay K.; Bedoya, Diego J.; Feng, Qin; Minami, Takashi; Mitsiades, Constantine S.; Frolov, Anna; Weigel, Nancy L.; Hilsenbeck, Susan G.; Rosen, Daniel G.; Palzkill, Timothy; Ittmann, Michael M.; Song, Yongcheng; Coarfa, Cristian; O’Malley, Bert W.; Mitsiades, Nicholas

    2014-01-01

    The androgen receptor (AR) is a key driver of prostate cancer (PC), even in the state of castration-resistant PC (CRPC) and frequently even after treatment with second-line hormonal therapies such as abiraterone and enzalutamide. The persistence of AR activity via both ligand-dependent and ligand-independent mechanisms (including constitutively active AR splice variants) highlights the unmet need for alternative approaches to block AR signaling in CRPC. We investigated the transcription factor GATA-binding protein 2 (GATA2) as a regulator of AR signaling and an actionable therapeutic target in PC. We demonstrate that GATA2 directly promotes expression of both full-length and splice-variant AR, resulting in a strong positive correlation between GATA2 and AR expression in both PC cell lines and patient specimens. Conversely, GATA2 expression is repressed by androgen and AR, suggesting a negative feedback regulatory loop that, upon androgen deprivation, derepresses GATA2 to contribute to AR overexpression in CRPC. Simultaneously, GATA2 is necessary for optimal transcriptional activity of both full-length and splice-variant AR. GATA2 colocalizes with AR and Forkhead box protein A1 on chromatin to enhance recruitment of steroid receptor coactivators and formation of the transcriptional holocomplex. In agreement with these important functions, high GATA2 expression and transcriptional activity predicted worse clinical outcome in PC patients. A GATA2 small molecule inhibitor suppressed the expression and transcriptional function of both full-length and splice-variant AR and exerted potent anticancer activity against PC cell lines. We propose pharmacological inhibition of GATA2 as a first-in-field approach to target AR expression and function and improve outcomes in CRPC. PMID:25489091

  19. Towards an automated selection of spontaneous co-activity maps in functional magnetic resonance imaging

    NASA Astrophysics Data System (ADS)

    Sourty, Marion; Thoraval, Laurent; Roquet, Daniel; Armspach, Jean-Paul; Foucher, Jack

    2015-03-01

    Functional magnetic resonance imaging allows to assess large scale functional integration of the brain. One of the leading techniques to extract functionally relevant networks is spatial independent component analysis (ICA). Spatial ICA separates independent spatial sources, many of whom are noise or imaging artifacts, whereas some do correspond to functionally relevant Spontaneous co-Activity Maps (SAMs). For research purposes, ICA is generally performed on group data. This strategy is well adapted to uncover commonly shared networks, e.g. resting-state networks, but fails to capture idiosyncratic functional networks which may be related to pathological activity, e.g. epilepsy, hallucinations. To capture these subject specific networks, ICA has to be applied to single subjects using a large number of components, from which a tenth are SAMs. Up to now, SAMs have to be selected manually by an expert based on predefined criteria. We aim to semi-automate the selection process in order to save time. To this end, some approaches have been proposed but none with the near 100 % sensitivity required for clinical purposes. In this paper, we propose a computerized version of the SAM's criteria used by experts, based on frequential and spatial characteristics of functional networks. Here we present a pre-selection method and its results at different resolutions, with different scanners or imaging sequences. While preserving a near 100 % sensitivity, it allows an average of 70 % reduction of components to be classified which save 55% of experts' time. In comparison, group ICA fails to detect about 25% of the SAMs.

  20. Acceleration of the Glycolytic Flux by Steroid Receptor Coactivator-2 Is Essential for Endometrial Decidualization

    PubMed Central

    Kommagani, Ramakrishna; Szwarc, Maria M.; Kovanci, Ertug; Gibbons, William E.; Putluri, Nagireddy; Maity, Suman; Creighton, Chad J.; Sreekumar, Arun; DeMayo, Francesco J.; Lydon, John P.; O'Malley, Bert W.

    2013-01-01

    Early embryo miscarriage is linked to inadequate endometrial decidualization, a cellular transformation process that enables deep blastocyst invasion into the maternal compartment. Although much of the cellular events that underpin endometrial stromal cell (ESC) decidualization are well recognized, the individual gene(s) and molecular pathways that drive the initiation and progression of this process remain elusive. Using a genetic mouse model and a primary human ESC culture model, we demonstrate that steroid receptor coactivator-2 (SRC-2) is indispensable for rapid steroid hormone-dependent proliferation of ESCs, a critical cell-division step which precedes ESC terminal differentiation into decidual cells. We reveal that SRC-2 is required for increasing the glycolytic flux in human ESCs, which enables rapid proliferation to occur during the early stages of the decidualization program. Specifically, SRC-2 increases the glycolytic flux through induction of 6-phosphofructo-2-kinase/fructose-2, 6-bisphosphatase 3 (PFKFB3), a major rate-limiting glycolytic enzyme. Similarly, acute treatment of mice with a small molecule inhibitor of PFKFB3 significantly suppressed the ability of these animals to exhibit an endometrial decidual response. Together, these data strongly support a conserved mechanism of action by which SRC-2 accelerates the glycolytic flux through PFKFB3 induction to provide the necessary bioenergy and biomass to meet the demands of a high proliferation rate observed in ESCs prior to their differentiation into decidual cells. Because deregulation of endometrial SRC-2 expression has been associated with common gynecological disorders of reproductive-age women, this signaling pathway, involving SRC-2 and PFKFB3, promises to offer new clinical approaches in the diagnosis and/or treatment of a non-receptive uterus in patients presenting idiopathic infertility, recurrent early pregnancy loss, or increased time to pregnancy. PMID:24204309

  1. Identification of two independent nucleosome-binding domains in the transcriptional co-activator SPBP.

    PubMed

    Darvekar, Sagar; Johnsen, Sylvia Sagen; Eriksen, Agnete Bratsberg; Johansen, Terje; Sjøttem, Eva

    2012-02-15

    Transcriptional regulation requires co-ordinated action of transcription factors, co-activator complexes and general transcription factors to access specific loci in the dense chromatin structure. In the present study we demonstrate that the transcriptional co-regulator SPBP [stromelysin-1 PDGF (platelet-derived growth factor)-responsive element binding protein] contains two independent chromatin-binding domains, the SPBP-(1551-1666) region and the C-terminal extended PHD [ePHD/ADD (extended plant homeodomain/ATRX-DNMT3-DNMT3L)] domain. The region 1551-1666 is a novel core nucleosome-interaction domain located adjacent to the AT-hook motif in the DNA-binding domain. This novel nucleosome-binding region is critically important for proper localization of SPBP in the cell nucleus. The ePHD/ADD domain associates with nucleosomes in a histone tail-dependent manner, and has significant impact on the dynamic interaction between SPBP and chromatin. Furthermore, SPBP and its homologue RAI1 (retinoic-acid-inducible protein 1), are strongly enriched on chromatin in interphase HeLa cells, and both proteins display low nuclear mobility. RAI1 contains a region with homology to the novel nucleosome-binding region SPBP-(1551-1666) and an ePHD/ADD domain with ability to bind nucleosomes. These results indicate that the transcriptional co-regulator SPBP and its homologue RAI1 implicated in Smith-Magenis syndrome and Potocki-Lupski syndrome both belong to the expanding family of chromatin-binding proteins containing several domains involved in specific chromatin interactions. PMID:22081970

  2. Role of the nuclear receptor coactivator AIB1/SRC-3 in angiogenesis and wound healing.

    PubMed

    Al-Otaiby, Maram; Tassi, Elena; Schmidt, Marcel O; Chien, Chris D; Baker, Tabari; Salas, Armando Ganoza; Xu, Jianming; Furlong, Mary; Schlegel, Richard; Riegel, Anna T; Wellstein, Anton

    2012-04-01

    The nuclear receptor coactivator amplified in breast cancer 1 (AIB1/SRC-3) has a well-defined role in steroid and growth factor signaling in cancer and normal epithelial cells. Less is known about its function in stromal cells, although AIB1/SRC-3 is up-regulated in tumor stroma and may, thus, contribute to tumor angiogenesis. Herein, we show that AIB1/SRC-3 depletion from cultured endothelial cells reduces their proliferation and motility in response to growth factors and prevents the formation of intact monolayers with tight junctions and of endothelial tubes. In AIB1/SRC-3(+/-) and (-/-) mice, the angiogenic responses to subcutaneous Matrigel implants was reduced by two-thirds, and exogenously added fibroblast growth factor (FGF) 2 did not overcome this deficiency. Furthermore, AIB1/SRC-3(+/-) and (-/-) mice showed similarly delayed healing of full-thickness excisional skin wounds, indicating that both alleles were required for proper tissue repair. Analysis of this defective wound healing showed reduced recruitment of inflammatory cells and macrophages, cytokine induction, and metalloprotease activity. Skin grafts from animals with different AIB1 genotypes and subsequent wounding of the grafts revealed that the defective healing was attributable to local factors and not to defective bone marrow responses. Indeed, wounds in AIB1(+/-) mice showed reduced expression of FGF10, FGFBP3, FGFR1, FGFR2b, and FGFR3, major local drivers of angiogenesis. We conclude that AIB1/SRC-3 modulates stromal cell responses via cross-talk with the FGF signaling pathway. PMID:22342158

  3. Steroid receptor coactivators 1 and 2 mediate fetal-to-maternal signaling that initiates parturition

    PubMed Central

    Gao, Lu; Rabbitt, Elizabeth H.; Condon, Jennifer C.; Renthal, Nora E.; Johnston, John M.; Mitsche, Matthew A.; Chambon, Pierre; Xu, Jianming; O’Malley, Bert W.; Mendelson, Carole R.

    2015-01-01

    The precise mechanisms that lead to parturition are incompletely defined. Surfactant protein-A (SP-A), which is secreted by fetal lungs into amniotic fluid (AF) near term, likely provides a signal for parturition; however, SP-A–deficient mice have only a relatively modest delay (~12 hours) in parturition, suggesting additional factors. Here, we evaluated the contribution of steroid receptor coactivators 1 and 2 (SRC-1 and SRC-2), which upregulate SP-A transcription, to the parturition process. As mice lacking both SRC-1 and SRC-2 die at birth due to respiratory distress, we crossed double-heterozygous males and females. Parturition was severely delayed (~38 hours) in heterozygous dams harboring SRC-1/-2–deficient embryos. These mothers exhibited decreased myometrial NF-κB activation, PGF2α, and expression of contraction-associated genes; impaired luteolysis; and elevated circulating progesterone. These manifestations also occurred in WT females bearing SRC-1/-2 double-deficient embryos, indicating that a fetal-specific defect delayed labor. SP-A, as well as the enzyme lysophosphatidylcholine acyltransferase-1 (LPCAT1), required for synthesis of surfactant dipalmitoylphosphatidylcholine, and the proinflammatory glycerophospholipid platelet-activating factor (PAF) were markedly reduced in SRC-1/-2–deficient fetal lungs near term. Injection of PAF or SP-A into AF at 17.5 days post coitum enhanced uterine NF-κB activation and contractile gene expression, promoted luteolysis, and rescued delayed parturition in SRC-1/-2–deficient embryo-bearing dams. These findings reveal that fetal lungs produce signals to initiate labor when mature and that SRC-1/-2–dependent production of SP-A and PAF is crucial for this process. PMID:26098214

  4. Perturbing the Cellular Levels of Steroid Receptor Coactivator-2 Impairs Murine Endometrial Function

    PubMed Central

    Szwarc, Maria M.; Kommagani, Ramakrishna; Jeong, Jae-Wook; Wu, San-Pin; Tsai, Sophia Y.; Tsai, Ming-Jer; O’Malley, Bert W.; DeMayo, Francesco J.; Lydon, John P.

    2014-01-01

    As pleiotropic coregulators, members of the p160/steroid receptor coactivator (SRC) family control a broad spectrum of transcriptional responses that underpin a diverse array of physiological and pathophysiological processes. Because of their potent coregulator properties, strict controls on SRC expression levels are required to maintain normal tissue functionality. Accordingly, an unwarranted increase in the cellular levels of SRC members has been causally linked to the initiation and/or progression of a number of clinical disorders. Although knockout mouse models have underscored the critical non-redundant roles for each SRC member in vivo, there are surprisingly few mouse models that have been engineered to overexpress SRCs. This deficiency is significant since SRC involvement in many of these disorders is based on unscheduled increases in the levels (rather than the absence) of SRC expression. To address this deficiency, we used recent mouse technology that allows for the targeted expression of human SRC-2 in cells which express the progesterone receptor. Through cre-loxP recombination driven by the endogenous progesterone receptor promoter, a marked elevation in expression levels of human SRC-2 was achieved in endometrial cells that are positive for the progesterone receptor. As a result of this increase in coregulator expression, female mice are severely subfertile due to a dysfunctional uterus, which exhibits a hypersensitivity to estrogen exposure. Our findings strongly support the proposal from clinical observations that increased levels of SRC-2 are causal for a number of endometrial disorders which compromise fertility. Future studies will use this mouse model to decipher the molecular mechanisms that underpin the endometrial defect. We believe such mechanistic insight may provide new molecular descriptors for diagnosis, prognosis, and/or therapy in the clinical management of female infertility. PMID:24905738

  5. Pathways to Play: Developing Play Skills in Young Children.

    ERIC Educational Resources Information Center

    Heidemann, Sandra; Hewitt, Deborah

    Play skills are vital to a child's overall healthy development. However, the training many caregivers receive may not include extensive information on play skills. This book presents a play checklist to help caregivers observe children's play skills, pinpoint play skills on which children need to work, and plan goals for improving those play…

  6. Modeling violations of the race model inequality in bimodal paradigms: co-activation from decision and non-decision components

    PubMed Central

    Zehetleitner, Michael; Ratko-Dehnert, Emil; Müller, Hermann J.

    2015-01-01

    The redundant-signals paradigm (RSP) is designed to investigate response behavior in perceptual tasks in which response-relevant targets are defined by either one or two features, or modalities. The common finding is that responses are speeded for redundantly compared to singly defined targets. This redundant-signals effect (RSE) can be accounted for by race models if the response times do not violate the race model inequality (RMI). When there are violations of the RMI, race models are effectively excluded as a viable account of the RSE. The common alternative is provided by co-activation accounts, which assume that redundant target signals are integrated at some processing stage. However, “co-activation” has mostly been only indirectly inferred and the accounts have only rarely been explicitly modeled; if they were modeled, the RSE has typically been assumed to have a decisional locus. Yet, there are also indications in the literature that the RSE might originate, at least in part, at a non-decisional or motor stage. In the present study, using a distribution analysis of sequential-sampling models (ex-Wald and Ratcliff Diffusion model), the locus of the RSE was investigated for two bimodal (audio-visual) detection tasks that strongly violated the RMI, indicative of substantial co-activation. Three model variants assuming different loci of the RSE were fitted to the quantile reaction time proportions: a decision, a non-decision, and a combined variant both to vincentized group as well as individual data. The results suggest that for the two bimodal detection tasks, co-activation has a shared decisional and non-decisional locus. These findings point to the possibility that the mechanisms underlying the RSE depend on the specifics (task, stimulus, conditions, etc.) of the experimental paradigm. PMID:25805987

  7. Phosphorylation of ETS Transcription Factor ER81 in a Complex with Its Coactivators CREB-Binding Protein and p300

    PubMed Central

    Papoutsopoulou, Stamatia; Janknecht, Ralf

    2000-01-01

    The ETS protein ER81 is a DNA-binding factor capable of enhancing gene transcription and is implicated in cellular transformation, but presently the mechanisms of its actions are unclear. In this report, ER81 is shown to coimmunoprecipitate with the transcriptional coactivator CREB-binding protein (CBP) and the related p300 protein (together referred to as CBP/p300). Moreover, confocal laser microscopic studies demonstrated that ER81 and p300 colocalized to nuclear speckles. In vitro and in vivo interaction studies revealed that ER81 amino acids 249 to 429, which encompass the ETS DNA-binding domain, are responsible for binding to CBP/p300. However, mutation of a putative protein-protein interaction motif, LXXLL, in the ETS domain of ER81 did not affect interaction with CBP/p300, whereas DNA binding of ER81 was abolished. Furthermore, two regions within CBP, amino acids 451 to 721 and 1891 to 2175, are capable of binding to ER81. Consistent with the physical interaction between ER81 and the coactivators CBP and p300, ER81 transcriptional activity was potentiated by CBP/p300 overexpression. Moreover, an ER81-associated protein kinase activity was enhanced upon p300 overexpression. This protein kinase phosphorylates ER81 on serines 191 and 216, and mutation of these phosphorylation sites increased ER81 transcriptional activity in Mv1Lu cells but not in HeLa cells. Altogether, our data elucidate the mechanism of how ER81 regulates gene transcription, through interaction with the coactivators CBP and p300 and an associated kinase that may cell type specifically modulate the ability of ER81 to activate gene transcription. PMID:10982847

  8. Peroxisome Proliferator-activated Receptor γ Coactivator-1 α Isoforms Selectively Regulate Multiple Splicing Events on Target Genes.

    PubMed

    Martínez-Redondo, Vicente; Jannig, Paulo R; Correia, Jorge C; Ferreira, Duarte M S; Cervenka, Igor; Lindvall, Jessica M; Sinha, Indranil; Izadi, Manizheh; Pettersson-Klein, Amanda T; Agudelo, Leandro Z; Gimenez-Cassina, Alfredo; Brum, Patricia C; Dahlman-Wright, Karin; Ruas, Jorge L

    2016-07-15

    Endurance and resistance exercise training induces specific and profound changes in the skeletal muscle transcriptome. Peroxisome proliferator-activated receptor γ coactivator-1 α (PGC-1α) coactivators are not only among the genes differentially induced by distinct training methods, but they also participate in the ensuing signaling cascades that allow skeletal muscle to adapt to each type of exercise. Although endurance training preferentially induces PGC-1α1 expression, resistance exercise activates the expression of PGC-1α2, -α3, and -α4. These three alternative PGC-1α isoforms lack the arginine/serine-rich (RS) and RNA recognition motifs characteristic of PGC-1α1. Discrete functions for PGC-1α1 and -α4 have been described, but the biological role of PGC-1α2 and -α3 remains elusive. Here we show that different PGC-1α variants can affect target gene splicing through diverse mechanisms, including alternative promoter usage. By analyzing the exon structure of the target transcripts for each PGC-1α isoform, we were able to identify a large number of previously unknown PGC-1α2 and -α3 target genes and pathways in skeletal muscle. In particular, PGC-1α2 seems to mediate a decrease in the levels of cholesterol synthesis genes. Our results suggest that the conservation of the N-terminal activation and repression domains (and not the RS/RNA recognition motif) is what determines the gene programs and splicing options modulated by each PGC-1α isoform. By using skeletal muscle-specific transgenic mice for PGC-1α1 and -α4, we could validate, in vivo, splicing events observed in in vitro studies. These results show that alternative PGC-1α variants can affect target gene expression both quantitatively and qualitatively and identify novel biological pathways under the control of this system of coactivators. PMID:27231350

  9. Tudor-SN, a Novel Coactivator of Peroxisome Proliferator-activated Receptor γ Protein, Is Essential for Adipogenesis*

    PubMed Central

    Duan, Zhongchao; Zhao, Xiujuan; Fu, Xiao; Su, Chao; Xin, Lingbiao; Saarikettu, Juha; Yang, Xi; Yao, Zhi; Silvennoinen, Olli; Wei, Minxin; Yang, Jie

    2014-01-01

    Adipogenesis, in which mesenchymal precursor cells differentiate into mature adipocytes, is a well orchestrated process. In the present study we identified Tudor-SN as a novel co-activator of the transcription factor peroxisome proliferator-activated receptor γ (PPARγ). We provide the first evidence that Tudor-SN and PPARγ exist in the same complex. Both are up-regulated by the early factor C/EBPβ during adipogenesis and significantly influence the regulation of PPARγ target genes in both 3T3-L1 pre-adipocyte and mouse embryonic fibroblasts (MEF) upon exposure to a mixture of hormonal mixture. Moreover, aP2-PPARγ response element (PPRE) interacts with both PPARγ and Tudor-SN, and the gene transcriptional activation of PPRE-luc is enhanced by ectopic expression of Tudor-SN. Deletion of Tudor-SN protein (MEF-KO) affects but does not completely abolish the association of PPARγ and aP2-PPRE. Loss-of-function studies further verified that Tudor-SN is required for adipogenesis, as deletion of Tudor-SN (MEF-KO) impairs dexamethasone, 3-isobutyl-1-methylxanthine, and insulin (DMI)-induced adipocyte differentiation and the expression of PPARγ target genes, such as aP2 and adipsin. Furthermore, H3 acetylation levels were lower in MEF-KO than MEF-WT. Both HDAC1 and HDAC3 are stably associated with PPARγ in MEF-KO, whereas only a small amount of association was observed in MEF-WT after 5 days of treatment during adipogenesis. PPARγ requires various co-activators or co-repressors, which may dynamically associate with and regulate the higher order chromatin remodeling of the promoter region of PPARγ-bound target genes; Tudor-SN is likely one of these co-activators. PMID:24523408

  10. Development through Work and Play.

    ERIC Educational Resources Information Center

    Hartung, Paul J.

    2002-01-01

    Five proposals are made for incorporating a work-play perspective in career development research: (1) fuse work and play conceptually over the life course; (2) imbue developmental career theory with a work-play fusion; (3) study work and play across the life span; (4) investigate work and play within the life space; and (5) consider a work-play…

  11. Play Theories: A Contemporary Review.

    ERIC Educational Resources Information Center

    Mellou, Eleni

    1994-01-01

    Reviews two sets of play theories, classical and modern, noting that the reason and purpose for play are explained by classical theories; the role of play in child development, determined by modern theories. States that process of play has dual functions of personal expression and social adaptation. Examines the relationship between play and…

  12. Play: Working Partner of Growth.

    ERIC Educational Resources Information Center

    McKee, Judy Spitler, Ed.

    This volume is a collection of nine papers focusing on different aspects of play. The first section, "Play, Growth, Development, and Learning," contains discussions dealing with make-believe play and learning; an all-in-fun approach to thinking, playing, and language learning for young children; and ways children learn through play. The second…

  13. Farm Hall: The Play

    NASA Astrophysics Data System (ADS)

    Cassidy, David C.

    2013-03-01

    It's July 1945. Germany is in defeat and the atomic bombs are on their way to Japan. Under the direction of Samuel Goudsmit, the Allies are holding some of the top German nuclear scientists-among them Heisenberg, Hahn, and Gerlach-captive in Farm Hall, an English country manor near Cambridge, England. As secret microphones record their conversations, the scientists are unaware of why they are being held or for how long. Thinking themselves far ahead of the Allies, how will they react to the news of the atomic bombs? How will these famous scientists explain to themselves and to the world their failure to achieve even a chain reaction? How will they come to terms with the horror of the Third Reich, their work for such a regime, and their behavior during that period? This one-act play is based upon the transcripts of their conversations as well as the author's historical work on the subject.

  14. Cobinamides Are Novel Coactivators of Nitric Oxide Receptor That Target Soluble Guanylyl Cyclase Catalytic Domain

    PubMed Central

    Sharina, Iraida; Sobolevsky, Michael; Doursout, Marie-Francoise; Gryko, Dorota

    2012-01-01

    Soluble guanylyl cyclase (sGC), a ubiquitously expressed heme-containing receptor for nitric oxide (NO), is a key mediator of NO-dependent processes. In addition to NO, a number of synthetic compounds that target the heme-binding region of sGC and activate it in a NO-independent fashion have been described. We report here that dicyanocobinamide (CN2-Cbi), a naturally occurring intermediate of vitamin B12 synthesis, acts as a sGC coactivator both in vitro and in intact cells. Heme depletion or heme oxidation does not affect CN2-Cbi-dependent activation. Deletion mutagenesis demonstrates that CN2-Cbi targets a new regulatory site and functions though a novel mechanism of sGC activation. Unlike all known sGC regulators that target the N-terminal regulatory regions, CN2-Cbi directly targets the catalytic domain of sGC, resembling the effect of forskolin on adenylyl cyclases. CN2-Cbi synergistically enhances sGC activation by NO-independent regulators 3-(4-amino-5-cyclopropylpyrimidine-2-yl)-1-(2-fluorobenzyl)-1H-pyrazolo[3,4-b]pyridine (BAY41-2272), 4-[((4-carboxybutyl){2-[(4-phenethylbenzyl)oxy]phenethyl}amino) methyl [benzoic]-acid (cinaciguat or BAY58-2667), and 5-chloro-2-(5-chloro-thiophene-2-sulfonylamino-N-(4-(morpholine-4-sulfonyl)-phenyl)-benzamide sodium salt (ataciguat or HMR-1766). BAY41-2272 and CN2-Cbi act reciprocally by decreasing the EC50 values. CN2-Cbi increases intracellular cGMP levels and displays vasorelaxing activity in phenylephrine-constricted rat aortic rings in an endothelium-independent manner. Both effects are synergistically potentiated by BAY41-2272. These studies uncover a new mode of sGC regulation and provide a new tool for understanding the mechanism of sGC activation and function. CN2-Cbi also offers new possibilities for its therapeutic applications in augmenting the effect of other sGC-targeting drugs. PMID:22171090

  15. Oxytocin Regulates Stress-Induced Crf Gene Transcription through CREB-Regulated Transcription Coactivator 3

    PubMed Central

    Jurek, Benjamin; Slattery, David A.; Hiraoka, Yuichi; Liu, Ying; Nishimori, Katsuhiko; Aguilera, Greti; van den Burg, Erwin H.

    2015-01-01

    The major regulator of the neuroendocrine stress response in the brain is corticotropin releasing factor (CRF), whose transcription is controlled by CREB and its cofactors CRTC2/3 (TORC2/3). Phosphorylated CRTCs are sequestered in the cytoplasm, but rapidly dephosphorylated and translocated into the nucleus following a stressful stimulus. As the stress response is attenuated by oxytocin (OT), we tested whether OT interferes with CRTC translocation and, thereby, Crf expression. OT (1 nmol, i.c.v.) delayed the stress-induced increase of nuclear CRTC3 and Crf hnRNA levels in the paraventricular nucleus of male rats and mice, but did not affect either parameter in the absence of the stressor. The increase in Crf hnRNA levels at later time points was parallel to elevated nuclear CRTC2/3 levels. A direct effect of Thr4 Gly7-OT (TGOT) on CRTC3 translocation and Crf expression was found in rat primary hypothalamic neurons, amygdaloid (Ar-5), hypothalamic (H32), and human neuroblastoma (Be(2)M17) cell lines. CRTC3, but not CRCT2, knockdown using siRNA in Be(2)M17 cells prevented the effect of TGOT on Crf hnRNA levels. Chromatin-immunoprecipitation demonstrated that TGOT reduced CRTC3, but not CRTC2, binding to the Crf promoter after 10 min of forskolin stimulation. Together, the results indicate that OT modulates CRTC3 translocation, the binding of CRTC3 to the Crf promoter and, ultimately, transcription of the Crf gene. SIGNIFICANCE STATEMENT The neuropeptide oxytocin has been proposed to reduce hypothalamic-pituitary-adrenal (HPA) axis activation during stress. The underlying mechanisms are, however, elusive. In this study we show that activation of the oxytocin receptor in the paraventricular nucleus delays transcription of the gene encoding corticotropin releasing factor (Crf), the main regulator of the stress response. It does so by sequestering the coactivator of the transcription factor CREB, CRTC3, in the cytosol, resulting in reduced binding of CRTC3 to the Crf

  16. Impaired coactivator activity of the Gly{sub 482} variant of peroxisome proliferator-activated receptor {gamma} coactivator-1{alpha} (PGC-1{alpha}) on mitochondrial transcription factor A (Tfam) promoter

    SciTech Connect

    Choi, Yon-Sik; Hong, Jung-Man; Lim, Sunny; Ko, Kyung Soo; Pak, Youngmi Kim . E-mail: ymkimpak@amc.seoul.kr

    2006-06-09

    Mitochondrial dysfunction may cause diabetes or insulin resistance. Peroxisome proliferation-activated receptor-{gamma} (PPAR-{gamma}) coactivator-1 {alpha} (PGC-1{alpha}) increases mitochondrial transcription factor A (Tfam) resulting in mitochondrial DNA content increase. An association between a single nucleotide polymorphism (SNP), G1444A(Gly482Ser), of PGC-1{alpha} coding region and insulin resistance has been reported in some ethnic groups. In this study, we investigated whether a change of glycine to serine at codon 482 of PGC-1{alpha} affected the Tfam promoter activity. The cDNA of PGC-1{alpha} variant bearing either glycine or serine at 482 codon was transfected into Chang human hepatocyte cells. The PGC-1{alpha} protein bearing glycine had impaired coactivator activity on Tfam promoter-mediated luciferase. We analyzed the PGC-1{alpha} genotype G1444A and mitochondrial DNA (mtDNA) copy number from 229 Korean leukocyte genomic DNAs. Subjects with Gly/Gly had a 20% lower amount of peripheral blood mtDNA than did subjects with Gly/Ser and Ser/Ser (p < 0.05). No correlation was observed between diabetic parameters and PGC-1{alpha} genotypes in Koreans. These results suggest that PGC-1{alpha} variants with Gly/Gly at 482nd amino acid may impair the Tfam transcription, a regulatory function of mitochondrial biogenesis, resulting in dysfunctional mtDNA replication.

  17. AMP-activated protein kinase is required for exercise-induced peroxisome proliferator-activated receptor γ co-activator 1α translocation to subsarcolemmal mitochondria in skeletal muscle

    PubMed Central

    Smith, Brennan K; Mukai, Kazutaka; Lally, James S; Maher, Amy C; Gurd, Brendon J; Heigenhauser, George J F; Spriet, Lawrence L; Holloway, Graham P

    2013-01-01

    In skeletal muscle, mitochondria exist as two subcellular populations known as subsarcolemmal (SS) and intermyofibrillar (IMF) mitochondria. SS mitochondria preferentially respond to exercise training, suggesting divergent transcriptional control of the mitochondrial genomes. The transcriptional co-activator peroxisome proliferator-activated receptor γ co-activator 1α (PGC-1α) and mitochondrial transcription factor A (Tfam) have been implicated in the direct regulation of the mitochondrial genome in mice, although SS and IMF differences may exist, and the potential signalling events regulating the mitochondrial content of these proteins have not been elucidated. Therefore, we examined the potential for PGC-1α and Tfam to translocate to SS and IMF mitochondria in human subjects, and performed experiments in rodents to identify signalling mechanisms regulating these translocation events. Acute exercise in humans and rats increased PGC-1α content in SS but not IMF mitochondria. Acute exposure to 5-aminoimidazole-4-carboxamide-1-β-ribofuranoside in rats recapitulated the exercise effect of increased PGC-1α protein within SS mitochondria only, suggesting that AMP-activated protein kinase (AMPK) signalling is involved. In addition, rendering AMPK inactive (AMPK kinase dead mice) prevented exercise-induced PGC-1α translocation to SS mitochondria, further suggesting that AMPK plays an integral role in these translocation events. In contrast to the conserved PGC-1α translocation to SS mitochondria across species (humans, rats and mice), acute exercise only increased mitochondrial Tfam in rats. Nevertheless, in rat resting muscle PGC-1α and Tfam co-immunoprecipate with α-tubulin, suggesting a common cytosolic localization. These data suggest that exercise causes translocation of PGC-1α preferentially to SS mitochondria in an AMPK-dependent manner. PMID:23297307

  18. SMAD3 Negatively Regulates Serum Irisin and Skeletal Muscle FNDC5 and Peroxisome Proliferator-activated Receptor γ Coactivator 1-α (PGC-1α) during Exercise*

    PubMed Central

    Tiano, Joseph P.; Springer, Danielle A.; Rane, Sushil G.

    2015-01-01

    Beige adipose cells are a distinct and inducible type of thermogenic fat cell that express the mitochondrial uncoupling protein-1 and thus represent a powerful target for treating obesity. Mice lacking the TGF-β effector protein SMAD3 are protected against diet-induced obesity because of browning of their white adipose tissue (WAT), leading to increased whole body energy expenditure. However, the role SMAD3 plays in WAT browning is not clearly understood. Irisin is an exercise-induced skeletal muscle hormone that induces WAT browning similar to that observed in SMAD3-deficient mice. Together, these observations suggested that SMAD3 may negatively regulate irisin production and/or secretion from skeletal muscle. To address this question, we used wild-type and SMAD3 knock-out (Smad3−/−) mice subjected to an exercise regime and C2C12 myotubes treated with TGF-β, a TGF-β receptor 1 pharmacological inhibitor, adenovirus expressing constitutively active SMAD3, or siRNA against SMAD3. We find that in Smad3−/− mice, exercise increases serum irisin and skeletal muscle FNDC5 (irisin precursor) and its upstream activator peroxisome proliferator-activated receptor γ coactivator 1-α (PGC-1α) to a greater extent than in wild-type mice. In C2C12 myotubes, TGF-β suppresses FNDC5 and PGC-1α mRNA and protein levels via SMAD3 and promotes SMAD3 binding to the FNDC5 and PGC-1α promoters. These data establish that SMAD3 suppresses FNDC5 and PGC-1α in skeletal muscle cells. These findings shed light on the poorly understood regulation of irisin/FNDC5 by demonstrating a novel association between irisin and SMAD3 signaling in skeletal muscle. PMID:25648888

  19. Placental DNA methylation of peroxisome-proliferator-activated receptor-γ co-activator-1α promoter is associated with maternal gestational glucose level.

    PubMed

    Xie, Xuemei; Gao, Hongjie; Zeng, Wanjiang; Chen, Suhua; Feng, Ling; Deng, Dongrui; Qiao, Fu-yuan; Liao, Lihong; McCormick, Kenneth; Ning, Qin; Luo, Xiaoping

    2015-08-01

    Intrauterine exposure to hyperglycaemia may increase the risk of later-life metabolic disorders. Although the underlying mechanism is not fully understood, epigenetic dysregulation in fetal programming has been implicated. With regard to energy homoeostasis, PGC-1α (peroxisome-proliferator-activated receptor γ co-activator-1α, encoded by the PPARGC1A gene) plays a regulatory role in several biochemical processes. We hypothesized that maternal gestational glucose levels would positively correlate with DNA methylation of the PPARGC1A promoter in placental tissue. We undertook a cross-sectional study of 58 mothers who underwent uncomplicated Caesarean delivery in a university hospital. Maternal gestational glucose concentration was determined after a 75-g OGTT (oral glucose tolerance test) at 24-28 weeks of gestation. Placenta tissue and cord blood were collected immediately after delivery. Genomic DNA was extracted and thereafter bisulfite conversion was performed. After PCR amplification, the DNA methylation of the PPARGC1A promoter was quantified using a pyrosequencing technique. The protein level of PGC-1α was evaluated by Western blotting. For all participants as a whole, including the GDM (gestational diabetes mellitus) and normoglycaemia groups, the maternal gestational glucose level was positively correlated with placental DNA methylation, and negatively correlated with cord blood DNA methylation of the PPARGC1A promoter in a CpG site-specific manner. In the GDM group alone, the placental CpG site-specific methylation of the PPARGC1A promoter strongly correlated with gestational 2-h post-OGTT glycaemia. Epigenetic alteration of the PPAGRC1A promoter may be one of the potential mechanisms underlying the metabolic programming in offspring exposed to intrauterine hyperglycaemia. PMID:25875376

  20. CREB coactivator CRTC2/TORC2 and its regulator calcineurin crucially mediate follicle-stimulating hormone and transforming growth factor β1 upregulation of steroidogenesis.

    PubMed

    Fang, Wei-Ling; Lee, Ming-Ting; Wu, Leang-Shin; Chen, Yun-Ju; Mason, Jian; Ke, Ferng-Chun; Hwang, Jiuan-Jiuan

    2012-06-01

    In vitro and in vivo studies implicate that follicle-stimulating hormone (FSH) and transforming growth factor β1 (TGFβ1) play crucial physiological roles in regulating ovarian granulosa cell function essential to fertility control in females. FSH induces cAMP and calcium signaling, thereby activating transcription factor CREB to upregulate steroidogenic gene expression, and TGFβ1 greatly enhances FSH-stimulated steroidogenesis. A CREB coactivator CRTC2/TORC2 was identified to function as a cAMP and calcium-sensitive coincidence sensor. This led us to explore the role of CRTC2 and its regulator calcineurin in FSH and TGFβ1-stimulated steroidogenesis. Primary culture of granulosa cells from gonadotropin-primed immature rats was used. Immunoblotting analysis shows that FSH rapidly and transiently induced dephosphorylation/activation of CRTC2, and FSH + TGFβ1 additionally induced late-phase CRTC2 dephosphorylation. Immunofluorescence analysis further confirms FSH ± TGFβ1 promoted CRTC2 nuclear translocation. Using selective inhibitors, we demonstrate that FSH activated CRTC2 in a PKA- and calcineurin-dependent manner, and TGFβ1 acting through its type I receptor (TGFβRI)-modulated FSH action in a calcineurin-mediated and PKA-independent fashion. Next, we investigated the involvement of calcineurin and CRTC2 in FSH and TGFβ1-stimulated steroidogenesis. Calcineurin and TGFβRI inhibitor dramatically reduced the FSH ± TGFβ1-increased progesterone synthesis and protein levels of StAR, P450scc, and 3β-HSD enzyme. Furthermore, chromatin-immunoprecipitation and immunoprecipitation analyses demonstrate that FSH ± TGFβ1 differentially increased CRTC2, CREB, and CBP binding to these steroidogenic genes, and CREB nuclear association with CRTC2 and CBP. In all, this study reveals for the first time that CRTC2 and calcineurin are critical signaling mediators in FSH and TGFβ1-stimulated steroidogenesis in ovarian granulosa cells. PMID:21826657

  1. Dose-dependent regulation of steroid receptor coactivator-1 and steroid receptors by testosterone propionate in the hippocampus of adult male mice.

    PubMed

    Qiu, Linli; Zhao, Yangang; Guo, Qiang; Zhang, Yuanyuan; He, Li; Li, Wei; Zhang, Jiqiang

    2016-02-01

    Androgens have been proposed to play important roles in the regulation of hippocampus function either directly, through the androgen receptor (AR), or indirectly, through estrogen receptors (ERs), after aromatization into estradiol. Steroid receptor coactivator-1 (SRC-1) is present in the hippocampus of several species, and its expression is regulated by development and aging, as well as by orchidectomy and aromatase inhibitor letrozole administration, while ovariectomy only transiently downregulated hippocampal SRC-1. However, whether the expression of hippocampal SRC-1 can be directly regulated by testosterone, the principal male sex hormone, remains unclear. In the present study, we investigated the expression of hippocampal SRC-1 after orchidectomy and testosterone treatment using immunohistochemistry and Western blot analysis. We found that while hippocampal SRC-1 was significantly downregulated by orchidectomy (ORX), its expression was rescued by treatment with testosterone in a dose-dependent manner. Furthermore, we noticed that the decreased expression of hippocampal AR, ERs and the synaptic proteins GluR-1 and PSD-95 induced by ORX was also rescued by testosterone treatment in a dose-dependent manner. However, we found that hippocampal membrane estrogen receptor GPR30 and dendritic spine marker spinophilin were not altered by ORX or testosterone treatment. Together, the above results provided the first direct evidence for the androgenic regulation on hippocampal SRC-1, indicating that SRC-1 may be a direct target of androgenic regulation on the hippocampus. Furthermore, because AR and ERs can be differentially regulated by testosterone, and the transcriptional activity requires the involvement of local SRC-1, and considering the complicated regulatory pathway of each individual receptor, the converged hub regulator SRC-1 of these nuclear receptor networks is worthy of further investigation. PMID:26607693

  2. TCDD-inducible poly-ADP-ribose polymerase (TIPARP/PARP7) mono-ADP-ribosylates and co-activates liver X receptors.

    PubMed

    Bindesbøll, Christian; Tan, Susanna; Bott, Debbie; Cho, Tiffany; Tamblyn, Laura; MacPherson, Laura; Grønning-Wang, Line; Nebb, Hilde Irene; Matthews, Jason

    2016-04-01

    Members of the poly-ADP-ribose polymerase (PARP) family catalyse the ADP-ribosylation of target proteins and are known to play important roles in many cellular processes, including DNA repair, differentiation and transcription. The majority of PARPs exhibit mono-ADP-ribosyltransferase activity rather than PARP activity; however, little is known about their biological activity. In the present study, we report that 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-inducible poly-ADP-ribose polymerase (TIPARP), mono-ADP-ribosylates and positively regulates liver X receptor α (LXRα) and LXRβ activity. Overexpression of TIPARP enhanced LXR-reporter gene activity. TIPARP knockdown or deletion reduced LXR regulated target gene expression levels in HepG2 cells and inTiparp(-/-)mouse embryonic fibroblasts (MEFs) respectively. Deletion and mutagenesis studies showed that TIPARP's zinc-finger and catalytic domains were required to enhance LXR activity. Protein interaction studies using TIPARP and LXRα/β peptide arrays revealed that LXRs interacted with an N-terminal sequence (a.a. 209-236) of TIPARP, which also overlapped with a putative co-activator domain of TIPARP (a.a. 200-225). Immunofluorescence studies showed that TIPARP and LXRα or LXRβ co-localized in the nucleus.In vitroribosylation assays provided evidence that TIPARP mono-ADP-ribosylated both LXRα and LXRβ. Co-immunoprecipitation (co-IP) studies revealed that ADP-ribosylase macrodomain 1 (MACROD1), but not MACROD2, interacted with LXRs in a TIPARP-dependent manner. This was complemented by reporter gene studies showing that MACROD1, but not MACROD2, prevented the TIPARP-dependent increase in LXR activity. GW3965-dependent increases in hepatic Srebp1 mRNA and protein expression levels were reduced inTiparp(-/-)mice compared withTiparp(+/+)mice. Taken together, these data identify a new mechanism of LXR regulation that involves TIPARP, ADP-ribosylation and MACROD1. PMID:26814197

  3. A preliminary investigation of the role of the transcription co-activators YAP/TAZ of the Hippo signalling pathway in canine and feline mammary tumours.

    PubMed

    Beffagna, G; Sacchetto, R; Cavicchioli, L; Sammarco, A; Mainenti, M; Ferro, S; Trez, D; Zulpo, M; Michieletto, S; Cecchinato, A; Goldschmidt, M; Zappulli, V

    2016-01-01

    Breast cancer is the most common cancer in women worldwide. Cancer metastases are responsible for the high mortality rate. A small but distinct subset of cells, cancer stem cells (CSCs), have the capacity to self-renew, initiate tumour formation, and develop metastases. The CSC content in human breast cancer correlates with the Hippo tumour suppressor signalling pathway. Specifically, the activity of YAP/TAZ, transcription co-activators of the Hippo pathway, sustains the self-renewal and tumour-initiation capacities of CSCs. Little is known about YAP/TAZ in canine and feline mammary tumours, which are very common tumours. The preliminary aim of the study was to investigate the expression of YAP/TAZ in canine and feline mammary tumours by Western blot and immunohistochemistry. Increased cytoplasmic and nuclear expression of YAP/TAZ was observed in all carcinomas compared to normal tissues, indicating neoplastic deregulation of the Hippo pathway. Nuclear expression significantly increased in grade III (high grade carcinomas) compared to grade I (low grade carcinomas) tumours, suggesting that YAP/TAZ play a role in the increased aggressiveness of these tumours. Moreover, different scoring systems for immunohistochemical analyses were compared and the H index and the Allred scores were the most significant. In conclusion, YAP/TAZ are expressed in aggressive canine and feline mammary tumours as reported in some human cancers. Further studies might better elucidate the role of the Hippo pathway in prognosis and as a target for new therapies. In addition, tumours in dogs and cats may be a useful model to study this pathway. PMID:26626094

  4. Child's Play: Revisiting Play in Early Childhood Settings.

    ERIC Educational Resources Information Center

    Dau, Elizabeth, Ed.; Jones, Elizabeth, Ed.

    Noting that play is an essential aspect of learning for young children, this book presents a collection of articles on children's play in Australia. Part 1, "Play, Development, and Learning," contains the following chapters: (1) "The Role of Play in Development and Learning" (Ann Glover); (2) "Stop, Look, and Listen: Adopting an Investigative…

  5. Imagination, Playfulness, and Creativity in Children's Play with Different Toys

    ERIC Educational Resources Information Center

    Mo????ller, Signe?? Juhl?

    2015-01-01

    Based on a four-month experimental study of preschool children's play with creative-construction and social-fantasy toys, the author examines the in?uence of both types of toys on the play of preschool children. Her comparative analysis considers the impact of transformative play on the development of imagination during play activities and…

  6. Playing My Heart Out: Original Play as Adventure.

    ERIC Educational Resources Information Center

    Donaldson, O. Fred

    1999-01-01

    "Original" play denotes play that is pre-cultural--before conceptualizations and learned responses. Four anecdotes about play with an infant with Down's syndrome, a child with leukemia, a lioness, and a dying woman illustrate the connections between beings and between the ordinary and the sacred during trusting, fearless, playful encounters. (SV)

  7. Facilitation of Play Behavior from Associative to Cooperative Play Stages.

    ERIC Educational Resources Information Center

    Lounsbury, Karen Rasmussen; Bell, Corinne Reed

    An experimental investigation of the transition from associative play to cooperative play was conducted to determine if cooperative play in young children could be facilitated by (1) presenting a toy that required cooperative responses to make it operate, and (2) instructing the children in the use of the toy prior to having them play with it. A…

  8. The estrogen-related receptor α (ERRα) functions in PPARγ coactivator 1α (PGC-1α)-induced mitochondrial biogenesis

    PubMed Central

    Schreiber, Sylvia N.; Emter, Roger; Hock, M. Benjamin; Knutti, Darko; Cardenas, Jessica; Podvinec, Michael; Oakeley, Edward J.; Kralli, Anastasia

    2004-01-01

    Estrogen-related receptor α (ERRα) is one of the first orphan nuclear receptors to be identified, yet its physiological functions are still unclear. We show here that ERRα is an effector of the transcriptional coactivator PGC-1α [peroxisome proliferator-activated receptor γ (PPARγ) coactivator 1α], and that it regulates the expression of genes involved in oxidative phosphorylation and mitochondrial biogenesis. Inhibition of ERRα compromises the ability of PGC-1α to induce the expression of genes encoding mitochondrial proteins and to increase mitochondrial DNA content. A constitutively active form of ERRα is sufficient to elicit both responses. ERRα binding sites are present in the transcriptional control regions of ERRα/PGC-1α-induced genes and contribute to the transcriptional response to PGC-1α. The ERRα-regulated genes described here have been reported to be expressed at reduced levels in humans that are insulin-resistant. Thus, changes in ERRα activity could be linked to pathological changes in metabolic disease, such as diabetes. PMID:15087503

  9. The PGC-1 coactivators promote an anti-inflammatory environment in skeletal muscle in vivo

    SciTech Connect

    Eisele, Petra Sabine; Furrer, Regula; Beer, Markus

    2015-08-28

    The peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) is abundantly expressed in trained muscles and regulates muscle adaptation to endurance exercise. Inversely, mice lacking a functional PGC-1α allele in muscle exhibit reduced muscle functionality and increased inflammation. In isolated muscle cells, PGC-1α and the related PGC-1β counteract the induction of inflammation by reducing the activity of the nuclear factor κB (NFκB). We now tested the effects of these metabolic regulators on inflammatory reactions in muscle tissue of control and muscle-specific PGC-1α/-1β transgenic mice in vivo in the basal state as well as after an acute inflammatory insult. Surprisingly, we observed a PGC-1-dependent alteration of the cytokine profile characterized by an increase in anti-inflammatory factors and a strong suppression of the pro-inflammatory interleukin 12 (IL-12). In conclusion, the anti-inflammatory environment in muscle that is promoted by the PGC-1s might contribute to the beneficial effects of these coactivators on muscle function and provides a molecular link underlying the tight mutual regulation of metabolism and inflammation. - Highlights: • Muscle PGC-1s are insufficient to prevent acute systemic inflammation. • The muscle PGC-1s however promote a local anti-inflammatory environment. • This anti-inflammatory environment could contribute to the therapeutic effect of the PGC-1s.

  10. Structural basis for recruitment of CBP/p300 coactivators by STAT1 and STAT2 transactivation domains

    PubMed Central

    Wojciak, Jonathan M; Martinez-Yamout, Maria A; Dyson, H Jane; Wright, Peter E

    2009-01-01

    CBP/p300 transcriptional coactivators mediate gene expression by integrating cellular signals through interactions with multiple transcription factors. To elucidate the molecular and structural basis for CBP-dependent gene expression, we determined structures of the CBP TAZ1 and TAZ2 domains in complex with the transactivation domains (TADs) of signal transducer and activator of transcription 2 (STAT2) and STAT1, respectively. Despite the topological similarity of the TAZ1 and TAZ2 domains, subtle differences in helix packing and surface grooves constitute major determinants of target selectivity. Our results suggest that TAZ1 preferentially binds long TADs capable of contacting multiple surface grooves simultaneously, whereas smaller TADs that are restricted to a single contiguous binding surface form complexes with TAZ2. Complex formation for both STAT TADs involves coupled folding and binding, driven by intermolecular hydrophobic and electrostatic interactions. Phosphorylation of S727, required for maximal transcriptional activity of STAT1, does not enhance binding to any of the CBP domains. Because the different STAT TADs recognize different regions of CBP/p300, there is a potential for multivalent binding by STAT heterodimers that could enhance the recruitment of the coactivators to promoters. PMID:19214187

  11. Fast skeletal muscle troponin I is a co-activator of estrogen receptor-related receptor {alpha}

    SciTech Connect

    Li Yuping; Chen Bin; Chen Jian; Lou Guiyu; Chen Shiuan; Zhou Dujin

    2008-05-16

    ERR{alpha} (estrogen receptor-related receptor {alpha}) is a member of the nuclear receptor superfamily. To further our understanding of the detailed molecular mechanism of transcriptional regulation by ERR{alpha}, we searched for ERR{alpha}-interacting proteins using a yeast two-hybrid system by screening a human mammary gland cDNA expression library with the ligand-binding domain (LBD) of ERR{alpha} as the 'bait'. Fast skeletal muscle troponin I (TNNI2), along with several known nuclear receptor co-activators, were isolated. We demonstrated that TNNI2 localizes to the cell nucleus and interacts with ERR{alpha} in co-immunoprecipitation experiments. GST pull-down assays also revealed that TNNI2 interacts directly with ERR{alpha}. Through luciferase reporter gene assays, TNNI2 was found to enhance the transactivity of ERR{alpha}. Combining mutagenesis and yeast two-hybrid assays, we mapped the ERR{alpha}-interacting domain on TNNI2 to a region encompassing amino acids 1-128. These findings reveal a new function for TNNI2 as a co-activator of ERR{alpha}.

  12. DCA1 Acts as a Transcriptional Co-activator of DST and Contributes to Drought and Salt Tolerance in Rice.

    PubMed

    Cui, Long-Gang; Shan, Jun-Xiang; Shi, Min; Gao, Ji-Ping; Lin, Hong-Xuan

    2015-10-01

    Natural disasters, including drought and salt stress, seriously threaten food security. In previous work we cloned a key zinc finger transcription factor gene, Drought and Salt Tolerance (DST), a negative regulator of drought and salt tolerance that controls stomatal aperture in rice. However, the exact mechanism by which DST regulates the expression of target genes remains unknown. In the present study, we demonstrated that DST Co-activator 1 (DCA1), a previously unknown CHY zinc finger protein, acts as an interacting co-activator of DST. DST was found to physically interact with itself and to form a heterologous tetramer with DCA1. This transcriptional complex appears to regulate the expression of peroxidase 24 precursor (Prx 24), a gene encoding an H2O2 scavenger that is more highly expressed in guard cells. Downregulation of DCA1 significantly enhanced drought and salt tolerance in rice, and overexpression of DCA1 increased sensitivity to stress treatment. These phenotypes were mainly influenced by DCA1 and negatively regulated stomatal closure through the direct modulation of genes associated with H2O2 homeostasis. Our findings establish a framework for plant drought and salt stress tolerance through the DCA1-DST-Prx24 pathway. Moreover, due to the evolutionary and functional conservation of DCA1 and DST in plants, engineering of this pathway has the potential to improve tolerance to abiotic stress in other important crop species. PMID:26496194

  13. Co-activation of NR2A and NR2B subunits induces resistance to fear extinction.

    PubMed

    Leaderbrand, Katherine; Corcoran, Kevin A; Radulovic, Jelena

    2014-09-01

    Unpredictable stress is known to profoundly enhance susceptibility to fear and anxiety while reducing the ability to extinguish fear when threat is no longer present. Accordingly, partial aversive reinforcement, via random exposure to footshocks, induces fear that is resistant to extinction. Here we sought to determine the hippocampal mechanisms underlying susceptibility versus resistance to context fear extinction as a result of continuous (CR) and partial (PR) reinforcement, respectively. We focused on N-methyl-D-aspartate receptor (NMDAR) subunits 2A and B (NR2A and NR2B) as well as their downstream signaling effector, extracellular signal-regulated kinase (ERK), based on their critical role in the acquisition and extinction of fear. Pharmacological inactivation of NR2A, but not NR2B, blocked extinction after CR, whereas inactivation of NR2A, NR2B, or both subunits facilitated extinction after PR. The latter finding suggests that co-activation of NR2A and NR2B contributes to persistent fear following PR. In contrast to CR, PR increased membrane levels of ERK and NR2 subunits after the conditioning and extinction sessions, respectively. In parallel, nuclear activation of ERK was significantly reduced after the extinction session. Thus, co-activation and increased surface expression of NR2A and NR2B, possibly mediated by ERK, may cause persistent fear. These findings suggest that patients with post-traumatic stress disorder (PTSD) may benefit from antagonism of specific NR2 subunits. PMID:24055686

  14. SCFCdc4 acts antagonistically to the PGC-1α transcriptional coactivator by targeting it for ubiquitin-mediated proteolysis

    PubMed Central

    Olson, Brian L.; Hock, M. Benjamin; Ekholm-Reed, Susanna; Wohlschlegel, James A.; Dev, Kumlesh K.; Kralli, Anastasia; Reed, Steven I.

    2008-01-01

    Peroxisome proliferator-activated receptor γ (PPARγ) coactivator-1α (PGC-1α) is a highly regulated transcriptional coactivator that coordinates energy metabolism in mammals. Misregulation of PGC-1α has been implicated in the pathogenesis of several human diseases, including diabetes, obesity, and neurological disorders. We identified SCFCdc4 as an E3 ubiquitin ligase that regulates PGC-1α through ubiquitin-mediated proteolysis. PGC-1α contains two Cdc4 phosphodegrons that bind Cdc4 when phosphorylated by Glycogen Synthase Kinase 3β (GSK3β) and p38 MAPK, leading to SCFCdc4-dependent ubiquitylation and proteasomal degradation of PGC-1α. Furthermore, SCFCdc4 negatively regulates PGC-1α-dependent transcription. We demonstrate that RNAi-mediated reduction of Cdc4 in primary neurons results in an increase of endogenous PGC-1α protein, while ectopic expression of Cdc4 leads to a reduction of endogenous PGC-1α protein. Finally, under conditions of oxidative stress in neurons, Cdc4 levels are decreased, leading to an increase in PGC-1α protein and PGC-1α-dependent transcription. These results suggest that attenuation of SCFCdc4-dependent proteasomal degradation of PGC-1α has a role in mediating the PGC-1α-dependent transcriptional response to oxidative stress. PMID:18198341

  15. Macrophage TCF-4 co-activates p65 to potentiate chronic inflammation and insulin resistance in mice.

    PubMed

    Kang, Xia; Hou, Along; Wang, Rui; Liu, Da; Xiang, Wei; Xie, Qingyun; Zhang, Bo; Gan, Lixia; Zheng, Wei; Miao, Hongming

    2016-07-01

    Transcription factor 4 (TCF-4) was recently identified as a candidate gene for the cause of type 2 diabetes, although the mechanisms have not been fully elucidated. In the present study, we demonstrated that the TCF-4 transgene in macrophages aggravated high-fat diet (HFD)-induced insulin resistance and chronic inflammation, characterized by the elevation of proinflammatory cytokines in the blood, liver and white adipose tissue, as well as a proinflammatory profile of immune cells in visceral fats in mice. Mechanistically, TCF-4 functioned as a co-activator of p65 to amplify the saturated free fatty acid (FFA)-stimulated promoter activity, mRNA transcription and secretion of proinflammatory cytokines in primary macrophages. Blockage of p65 with a specific interfering RNA or inhibitor could prevent TCF-4-enhanced expression of proinflammatory cytokines in FFA/lipopolysaccharide-treated primary macrophages. The p65 inhibitor could abolish macrophage TCF-4 transgene-aggravated systemic inflammation, glucose intolerance and insulin resistance in HFD-treated mice. In addition, we demonstrated that the mRNA expression of TCF-4 in the peripheral blood monocytes from humans was positively correlated to the levels of interleukin (IL)-1β, tumour necrosis factor α, IL-6 and fasting plasma glucose. In summary, we identified TCF-4 as a co-activator of p65 in the potentiation of proinflammatory cytokine production in macrophages and aggravation of HFD-induced chronic inflammation and insulin resistance in mice. PMID:27129186

  16. DCA1 Acts as a Transcriptional Co-activator of DST and Contributes to Drought and Salt Tolerance in Rice

    PubMed Central

    Cui, Long-Gang; Shan, Jun-Xiang; Shi, Min; Gao, Ji-Ping; Lin, Hong-Xuan

    2015-01-01

    Natural disasters, including drought and salt stress, seriously threaten food security. In previous work we cloned a key zinc finger transcription factor gene, Drought and Salt Tolerance (DST), a negative regulator of drought and salt tolerance that controls stomatal aperture in rice. However, the exact mechanism by which DST regulates the expression of target genes remains unknown. In the present study, we demonstrated that DST Co-activator 1 (DCA1), a previously unknown CHY zinc finger protein, acts as an interacting co-activator of DST. DST was found to physically interact with itself and to form a heterologous tetramer with DCA1. This transcriptional complex appears to regulate the expression of peroxidase 24 precursor (Prx 24), a gene encoding an H2O2 scavenger that is more highly expressed in guard cells. Downregulation of DCA1 significantly enhanced drought and salt tolerance in rice, and overexpression of DCA1 increased sensitivity to stress treatment. These phenotypes were mainly influenced by DCA1 and negatively regulated stomatal closure through the direct modulation of genes associated with H2O2 homeostasis. Our findings establish a framework for plant drought and salt stress tolerance through the DCA1-DST-Prx24 pathway. Moreover, due to the evolutionary and functional conservation of DCA1 and DST in plants, engineering of this pathway has the potential to improve tolerance to abiotic stress in other important crop species. PMID:26496194

  17. Metformin inhibits hepatocellular glucose, lipid and cholesterol biosynthetic pathways by transcriptionally suppressing steroid receptor coactivator 2 (SRC-2)

    PubMed Central

    Madsen, Andre; Bozickovic, Olivera; Bjune, Jan-Inge; Mellgren, Gunnar; Sagen, Jørn V.

    2015-01-01

    The ability of the anti-diabetic drug metformin to inhibit anabolic processes including gluconeogenesis and lipogenesis is partly attributable to activation of the AMP-activated protein kinase (AMPK) pathway. The p160 steroid receptor coactivator 2 (SRC-2) is a key regulator of cellular metabolism and drives expression of the gluconeogenic enzyme glucose-6-phosphatase (G6Pc). Here, we uncovered a role for SRC-2 in the metabolic reprogramming imposed by metformin. In FaO cells, metformin dose-dependently reduced mRNA expression of SRC-2. Microarray analysis of metformin-treated cells revealed an overrepresentation of downregulated genes involved in biosynthesis of lipids and cholesterol. Several metformin-regulated genes including fatty acid synthase (FASN) were validated as transcriptional targets of SRC-2 with promoters characterized by sterol regulatory element (SRE) binding protein (SREBP) recognition sequences. Transactivation assays of the FASN promoter confirmed that SRC-2 is a coactivator of SREBP-1. By suppressing SRC-2 at the transcriptional level, metformin impeded recruitment of SRC-2 and RNA polymerase II to the G6Pc promoter and to SREs of mutual SRC-2/SREBP-1 target gene promoters. Hepatocellular fat accretion was reduced by metformin or knock-down of both SRC-2 and SREBP-1. Accordingly we propose that metformin inhibits glucose and lipid biosynthesis partly by downregulating SRC-2 gene expression. PMID:26548416

  18. A novel role for TPX2 as a scaffold and co-activator protein of the Chromosomal Passenger Complex

    PubMed Central

    Iyer, Jyoti; Tsai, Ming-Ying

    2012-01-01

    Aurora B kinase forms the enzymatic core of the Chromosomal Passenger Complex (CPC) and is a master regulator of mitosis. Understanding the regulation of Aurora B is critical to illuminate its role in mitosis. INCENP, Survivin and Borealin have all been known to promote Aurora B activation. In this study, we have identified the Aurora A activator protein TPX2 as a novel scaffold and co-activator protein of the CPC. Studies utilizing M-phase Xenopus egg extracts (XEE) revealed that the immunodepletion of endogenous TPX2 from XEE decreases Aurora B-Survivin and Aurora B-INCENP interactions, leading to a consequent reduction in Aurora B activity. Further, residues 138 to 328 of Xenopus TPX2 (TPX2 B) are sufficient to enhance Aurora B-Survivin association and Aurora B kinase activity in vitro. Importantly, experiments with pancreatic cancer cell lines suggest that this mechanism of Aurora B activation by TPX2 is likely to be conserved in human cells. Strikingly, the overexpression of human TPX2 B in HeLa cells causes defects in metaphase chromosome alignment and INCENP localization. Thus, in addition to its already established role as an Aurora A activator, our data support the role of TPX2 as a novel co-activator of Aurora kinase B. PMID:22560880

  19. Playful Learning and Montessori Education

    ERIC Educational Resources Information Center

    Lillard, Angeline S.

    2013-01-01

    Although Montessori education is often considered a form of playful learning, Maria Montessori herself spoke negatively about a major component of playful learning--pretend play, or fantasy--for young children. In this essay, the author discusses this apparent contradiction: how and why Montessori education includes elements of playful learning…

  20. The Child's Right To Play.

    ERIC Educational Resources Information Center

    Morris, Beverley

    This paper argues that play is an important and fundamental educational process and that the child's right to play should be respected. The paper also comments on the 1990 Tokyo International Conference on the Child's Right to Play. Several issues related to children's play, both in and out of school, are discussed. The focus is on the state of…

  1. Music Learning and Child's Play.

    ERIC Educational Resources Information Center

    Littleton, Danette

    1998-01-01

    Reviews various studies on childs play and its relation to young childrens development in music learning processes and explores the role that cognitive and social play categories have in studying childrens play with music. Provides strategies for initiating music-play opportunities in a preschool classroom. (CMK)

  2. Play and Positive Group Dynamics

    ERIC Educational Resources Information Center

    Thompson, Pam; White, Samantha

    2010-01-01

    Play is an important part of a child's life and essential to learning and development (Vygotsky, 1978). It is vital that students participate in play and that play be conducted in a restorative manner. Play allows a variety of group dynamics to emerge. Irvin Yalom (1995) identifies 11 curative factors of the group experience. These factors include…

  3. Physiological correlates of the flow experience during computer game playing.

    PubMed

    Harmat, László; de Manzano, Örjan; Theorell, Töres; Högman, Lennart; Fischer, Håkan; Ullén, Fredrik

    2015-07-01

    Flow is the subjective experience of effortless attention, reduced self-awareness, and enjoyment that typically occurs during optimal task performance. Previous studies have suggested that flow may be associated with a non-reciprocal coactivation of the sympathetic and parasympathetic systems and, on a cortical level, with a state of hypofrontality and implicit processing. Here, we test these hypotheses, using the computer game TETRIS as model task. The participants (n=77) played TETRIS under three conditions that differed in difficulty (Easy

  4. Toy Play, Play Tempo, and Reaction to Frustration in Infants.

    ERIC Educational Resources Information Center

    Longo, Josephine; And Others

    1982-01-01

    In two sessions, the duration and tempo of toy play of infants and reaction of frustration were measured. Correlations indicated a general relationship between response persistence during play and attempts to escape frustrating situations. (Author/CM)

  5. Playing with Switches, Birth through Two. Let's Play! Project.

    ERIC Educational Resources Information Center

    State Univ. of New York, Buffalo. Center for Assistive Technology.

    This guide to playing with switches for parents and early intervention personnel was developed by the "Let's Play! Project," a 3-year federally supported project that worked to promote play in infants and toddlers with disabilities through the use of assistive technology. Switches are used with electronic toys to help young children easily…

  6. Increasing Joint Attention, Play and Language through Peer Supported Play.

    ERIC Educational Resources Information Center

    Zercher, Craig; Hunt, Pam; Schuler, Adriana; Webster, Janice

    2001-01-01

    This study examined effects of participation in an integrated play group on the social skills of two 6-year-old twins with autism. Following intervention with adult coaching, typical peers implemented the play group techniques in weekly play group sessions. The autistic subjects showed dramatic increases in shared attention to objects, symbolic…

  7. Solar Power at Play

    NASA Astrophysics Data System (ADS)

    2007-03-01

    For the very first time, astronomers have witnessed the speeding up of an asteroid's rotation, and have shown that it is due to a theoretical effect predicted but never seen before. The international team of scientists used an armada of telescopes to discover that the asteroid's rotation period currently decreases by 1 millisecond every year, as a consequence of the heating of the asteroid's surface by the Sun. Eventually it may spin faster than any known asteroid in the solar system and even break apart. ESO PR Photo 11a/07 ESO PR Photo 11a/07 Asteroid 2000 PH5 "The Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect is believed to alter the way small bodies in the Solar System rotate," said Stephen Lowry (Queens University Belfast, UK), lead-author of one of the two companion papers in which this work is reported [1, 2]. "The warming caused by sunlight hitting the surfaces of asteroids and meteoroids leads to a gentle recoil effect as the heat is released," he added. "By analogy, if one were to shine light on a propeller over a long enough period, it would start spinning." Although this is an almost immeasurably weak force, its effect over millions of years is far from negligible. Astronomers believe the YORP effect may be responsible for spinning some asteroids up so fast that they break apart, perhaps leading to the formation of double asteroids. Others may be slowed down so that they take many days to complete a full turn. The YORP effect also plays an important role in changing the orbits of asteroids between Mars and Jupiter, including their delivery to planet-crossing orbits, such as those of near-Earth asteroids. Despite its importance, the effect has never been seen acting on a solar system body, until now. Using extensive optical and radar imaging from powerful Earth-based observatories, astronomers have directly observed the YORP effect in action on a small near-Earth asteroid, known as (54509) 2000 PH5. Shortly after its discovery in 2000, it was

  8. The PGC-1α-related coactivator promotes mitochondrial and myogenic adaptations in C2C12 myotubes

    PubMed Central

    Philp, Andrew; Belew, Micah Y.; Evans, Ashleigh; Pham, Don; Sivia, Itwinder; Chen, Ai; Schenk, Simon

    2011-01-01

    The transcriptional coactivator PGC-1α is a potent regulator of skeletal muscle metabolism. Less is known about the structurally similar PGC-1α-related coactivator (PRC) that is enriched in myoblasts and adult skeletal muscle. The present study was designed to determine the effect of PRC on the metabolic profile of C2C12 myotubes. Overexpression of full-length PRC increased PRC gene expression by 2.7 ± 0.3-fold and protein content by 108 ± 5.3%. This modest elevation in PRC resulted in an increased rate of myoblast proliferation (61.5 ± 2.7%) and resulted in myotubes characterized by increased MyoD (18.2 ± 0.52%) and myosin heavy chain (15.4 ± 3.13%) protein. PRC overexpressing myotubes showed increases in mRNA for some—COX4 (2.6 ± 0.18-fold), ATP5B (2.7 ± 0.34-fold) cytochrome c (5.1 ± 0.68-fold)—but not all, MTCO1 (0.61 ± 0.18-fold) and HAD (0.98 ± 0.36-fold) mitochondrial genes, as well as a significant increase in cytochrome–c (28.7 ± 7.02%) protein content. The enzyme activity of the electron transport chain (ETC) complex IV (3.7 ± 0.01-fold) and citrate synthase (2.1 ± 0.14-fold) was increased by PRC, as was the mtDNA:nucDNA ratio (11 ± 0.3%). PRC increased cellular respiration (142%), basal (197%) and insulin-stimulated (253%) glucose uptake, as well as palmitate uptake (28.6 ± 3.31%) and oxidation (31.1 ± 2.17%). Associated with these changes in function, PRC overexpression increased GLUT4 mRNA (4.5 ± 0.22-fold) and protein (13.8 ± 2.08%) and CPT1 protein (28.9 ± 4.23%). Electrical stimulation of C2C12 myotubes resulted in a transient increase in PRC mRNA that was smaller (2.1 ± 0.3-fold vs. 4.4 ± 0.23-fold) and occurred earlier (3 h vs. 6 h) than PGC-1α. Collectively, our data show that PRC promotes skeletal muscle myogenesis and metabolism in vitro, thus identifying PRC as a functional skeletal muscle coactivator capable of regulating mitochondrial substrate utilization and respiration. PMID:21795630

  9. Co-Activity during Maximum Voluntary Contraction: A Study of Four Lower-Extremity Muscles in Children with and without Cerebral Palsy

    ERIC Educational Resources Information Center

    Tedroff, Kristina; Knutson, Loretta M.; Soderberg, Gary L.

    2008-01-01

    This study was designed to determine whether children with cerebral palsy (CP) showed more co-activity than comparison children in non-prime mover muscles with regard to the prime mover during maximum voluntary isometric contraction (MVIC) of four lower-extremity muscles. Fourteen children with spastic diplegic CP (10 males, four females; age…

  10. MicroRNA-22 and microRNA-140 suppress NF-{kappa}B activity by regulating the expression of NF-{kappa}B coactivators

    SciTech Connect

    Takata, Akemi; Otsuka, Motoyuki; Kojima, Kentaro; Yoshikawa, Takeshi; Kishikawa, Takahiro; Yoshida, Haruhiko; Koike, Kazuhiko

    2011-08-12

    Highlights: {yields} miRNAs were screened for their ability to regulate NF-{kappa}B activity. {yields} miRNA-22 and miRNA-140-3p suppress NF-{kappa}B activity by regulating coactivators. {yields} miRNA-22 targets nuclear receptor coactivator 1 (NCOA1). {yields} miRNA-140-3p targets nuclear receptor-interacting protein 1 (NRIP1). -- Abstract: Nuclear factor {kappa}B (NF-{kappa}B) is a transcription factor that regulates a set of genes that are critical to many biological phenomena, including liver tumorigenesis. To identify microRNAs (miRNAs) that regulate NF-{kappa}B activity in the liver, we screened 60 miRNAs expressed in hepatocytes for their ability to modulate NF-{kappa}B activity. We found that miRNA-22 and miRNA-140-3p significantly suppressed NF-{kappa}B activity by regulating the expression of nuclear receptor coactivator 1 (NCOA1) and nuclear receptor-interacting protein 1 (NRIP1), both of which are NF-{kappa}B coactivators. Our results provide new information about the roles of miRNAs in the regulation of NF-{kappa}B activity.

  11. Learning, Play, and Your Newborn

    MedlinePlus

    ... Story" 5 Things to Know About Zika & Pregnancy Learning, Play, and Your Newborn KidsHealth > For Parents > Learning, ... juega su recién nacido What Is My Newborn Learning? Play is the chief way that infants learn ...

  12. Medical Play for Young Children.

    ERIC Educational Resources Information Center

    Jessee, Peggy O.; Wilson, Heidi; Morgan, Dee

    2000-01-01

    Discusses young children's emotional responses during medical examinations and procedures, developmental changes in how they conceptualize illness causation, and the role of play to reduce stress. Describes how teachers can best facilitate structured dramatic medical play therapeutically. (KB)

  13. Problematic game play: the diagnostic value of playing motives, passion, and playing time in men.

    PubMed

    Kneer, Julia; Rieger, Diana

    2015-01-01

    Internet gaming disorder is currently listed in the DSM-not in order to diagnose such a disorder but to encourage research to investigate this phenomenon. Even whether it is still questionable if Internet Gaming Disorder exists and can be judged as a form of addiction, problematic game play is already very well researched to cause problems in daily life. Approaches trying to predict problematic tendencies in digital game play have mainly focused on playing time as a diagnostic criterion. However, motives to engage in digital game play and obsessive passion for game play have also been found to predict problematic game play but have not yet been investigated together. The present study aims at (1) analyzing if obsessive passion can be distinguished from problematic game play as separate concepts, and (2) testing motives of game play, passion, and playing time for their predictive values for problematic tendencies. We found (N = 99 males, Age: M = 22.80, SD = 3.81) that obsessive passion can be conceptually separated from problematic game play. In addition, the results suggest that compared to solely playing time immersion as playing motive and obsessive passion have added predictive value for problematic game play. The implications focus on broadening the criteria in order to diagnose problematic playing. PMID:25942516

  14. Problematic Game Play: The Diagnostic Value of Playing Motives, Passion, and Playing Time in Men

    PubMed Central

    Kneer, Julia; Rieger, Diana

    2015-01-01

    Internet gaming disorder is currently listed in the DSM—not in order to diagnose such a disorder but to encourage research to investigate this phenomenon. Even whether it is still questionable if Internet Gaming Disorder exists and can be judged as a form of addiction, problematic game play is already very well researched to cause problems in daily life. Approaches trying to predict problematic tendencies in digital game play have mainly focused on playing time as a diagnostic criterion. However, motives to engage in digital game play and obsessive passion for game play have also been found to predict problematic game play but have not yet been investigated together. The present study aims at (1) analyzing if obsessive passion can be distinguished from problematic game play as separate concepts, and (2) testing motives of game play, passion, and playing time for their predictive values for problematic tendencies. We found (N = 99 males, Age: M = 22.80, SD = 3.81) that obsessive passion can be conceptually separated from problematic game play. In addition, the results suggest that compared to solely playing time immersion as playing motive and obsessive passion have added predictive value for problematic game play. The implications focus on broadening the criteria in order to diagnose problematic playing. PMID:25942516

  15. Play Memories and Place Identity.

    ERIC Educational Resources Information Center

    Sandberg, Anette

    2003-01-01

    This retrospective study examined play memories from childhood to adulthood of 478 university students between ages 20 and 62 as exhibited in drawings of play memories and questionnaire responses. The study focused on the role of the physical environment and place identity in play memories and individual identity development. Findings showed that…

  16. Meanings of Play among Children

    ERIC Educational Resources Information Center

    Glenn, Nicole M.; Knight, Camilla J.; Holt, Nicholas L.; Spence, John C.

    2013-01-01

    The purpose of this study was to examine meanings of play among children. Thirty-eight students aged 7-9 years from a suburban public school in Western Canada participated in focus groups. Data analysis revealed participants saw almost anything as an opportunity for play and would play almost anywhere with anyone. However, they perceived parents…

  17. Play Therapy in School Counseling

    ERIC Educational Resources Information Center

    Trice-Black, Shannon; Bailey, Carrie Lynn; Kiper Riechel, Morgan E.

    2013-01-01

    Play therapy is an empirically supported intervention used to address a number of developmental issues faced in childhood. Through the natural language of play, children and adolescents communicate feelings, thoughts, and experiences. Schools provide an ideal setting for play therapy in many ways; however, several challenges exist in implementing…

  18. Play in Evolution and Development

    ERIC Educational Resources Information Center

    Pellegrini, Anthony D.; Dupuis, Danielle; Smith, Peter K.

    2007-01-01

    In this paper we examine the role of play in human ontogeny and phylogeny, following Surplus Resource Theory. We consider how juveniles use play to sample their environment in order to develop adaptive behaviors. We speculate about how innovative behaviors developed in play in response to environmental novelty may influence subsequent evolutionary…

  19. Pretend Play and Creative Processes

    ERIC Educational Resources Information Center

    Russ, Sandra W.; Wallace, Claire E.

    2013-01-01

    The authors contend that many cognitive abilities and affective processes important in creativity also occur in pretend play and that pretend play in childhood affects the development of creativity in adulthood. They discuss a variety of theories and observations that attempt to explain the importance of pretend play to creativity. They argue that…

  20. Preschoolers' Thinking during Block Play

    ERIC Educational Resources Information Center

    Piccolo, Diana L.; Test, Joan

    2010-01-01

    Children build foundations for mathematical thinking in early play and exploration. During the preschool years, children enjoy exploring mathematical concepts--such as patterns, shape, spatial relationships, and measurement--leading them to spontaneously engage in mathematical thinking during play. Block play is one common example that engages…

  1. Abiotic and biotic stress tolerance in Arabidopsis overexpressing the multiprotein bridging factor 1a (MBF1a) transcriptional coactivator gene.

    PubMed

    Kim, Min-Jung; Lim, Gah-Hyun; Kim, Eun-Seon; Ko, Chang-Beom; Yang, Kwang-Yeol; Jeong, Jin-An; Lee, Myung-Chul; Kim, Cheol Soo

    2007-03-01

    We conducted a genetic yeast screen to identify salt tolerance (SAT) genes in a maize kernel cDNA library. During the screening, we identified a maize clone (SAT41) that seemed to confer elevated salt tolerance in comparison to control cells. SAT41 cDNA encodes a 16-kDa protein which is 82.4% identical to the Arabidopsis Multiprotein bridging factor 1a (MBF1a) transcriptional coactivator gene. To further examine salinity tolerance in Arabidopsis, we functionally characterized the MBF1a gene and found that dehydration as well as heightened glucose (Glc) induced MBF1a expression. Constitutive expression of MBF1a in Arabidopsis led to elevated salt tolerance in transgenic lines. Interestingly, plants overexpressing MBF1a exhibited insensitivity to Glc and resistance to fungal disease. Our results suggest that MBF1a is involved in stress tolerance as well as in ethylene and Glc signaling in Arabidopsis. PMID:17234157

  2. The transcriptional coactivator PGC-1α is essential for maximal and efficient cardiac mitochondrial fatty acid oxidation and lipid homeostasis

    PubMed Central

    Lehman, John J.; Boudina, Sihem; Banke, Natasha Hausler; Sambandam, Nandakumar; Han, Xianlin; Young, Deanna M.; Leone, Teresa C.; Gross, Richard W.; Lewandowski, E. Douglas; Abel, E. Dale; Kelly, Daniel P.

    2008-01-01

    High-capacity mitochondrial ATP production is essential for normal function of the adult heart, and evidence is emerging that mitochondrial derangements occur in common myocardial diseases. Previous overexpression studies have shown that the inducible transcriptional coactivator peroxisome proliferator-activated receptor-γ coactivator (PGC)-1α is capable of activating postnatal cardiac myocyte mitochondrial biogenesis. Recently, we generated mice deficient in PGC-1α (PGC-1α−/− mice), which survive with modestly blunted postnatal cardiac growth. To determine if PGC-1α is essential for normal cardiac energy metabolic capacity, mitochondrial function experiments were performed on saponin-permeabilized myocardial fibers from PGC-1α−/− mice. These experiments demonstrated reduced maximal (state 3) palmitoyl-l-carnitine respiration and increased maximal (state 3) pyruvate respiration in PGC-1α−/− mice compared with PGC-1α+/+ controls. ATP synthesis rates obtained during maximal (state 3) respiration in permeabilized myocardial fibers were reduced for PGC-1α−/− mice, whereas ATP produced per oxygen consumed (ATP/O), a measure of metabolic efficiency, was decreased by 58% for PGC-1α−/− fibers. Ex vivo isolated working heart experiments demonstrated that PGC-1α−/− mice exhibited lower cardiac power, reduced palmitate oxidation, and increased reliance on glucose oxidation, with the latter likely a compensatory response. 13C NMR revealed that hearts from PGC-1α−/− mice exhibited a limited capacity to recruit triglyceride as a source for lipid oxidation during β-adrenergic challenge. Consistent with reduced mitochondrial fatty acid oxidative enzyme gene expression, the total triglyceride content was greater in hearts of PGC-1α−/− mice relative to PGC-1α+/+ following a fast. Overall, these results demonstrate that PGC-1α is essential for the maintenance of maximal, efficient cardiac mitochondrial fatty acid oxidation, ATP

  3. Coactivator PGC-1{alpha} regulates the fasting inducible xenobiotic-metabolizing enzyme CYP2A5 in mouse primary hepatocytes

    SciTech Connect

    Arpiainen, Satu; Jaervenpaeae, Sanna-Mari; Manninen, Aki; Viitala, Pirkko; Lang, Matti A.; Pelkonen, Olavi; Hakkola, Jukka

    2008-10-01

    The nutritional state of organisms and energy balance related diseases such as diabetes regulate the metabolism of xenobiotics such as drugs, toxins and carcinogens. However, the mechanisms behind this regulation are mostly unknown. The xenobiotic-metabolizing cytochrome P450 (CYP) 2A5 enzyme has been shown to be induced by fasting and by glucagon and cyclic AMP (cAMP), which mediate numerous fasting responses. Peroxisome proliferator-activated receptor {gamma} coactivator (PGC)-1{alpha} triggers many of the important hepatic fasting effects in response to elevated cAMP levels. In the present study, we were able to show that cAMP causes a coordinated induction of PGC-1{alpha} and CYP2A5 mRNAs in murine primary hepatocytes. Furthermore, the elevation of the PGC-1{alpha} expression level by adenovirus mediated gene transfer increased CYP2A5 transcription. Co-transfection of Cyp2a5 5' promoter constructs with the PGC-1{alpha} expression vector demonstrated that PGC-1{alpha} is able to activate Cyp2a5 transcription through the hepatocyte nuclear factor (HNF)-4{alpha} response element in the proximal promoter of the Cyp2a5 gene. Chromatin immunoprecipitation assays showed that PGC-1{alpha} binds, together with HNF-4{alpha}, to the same region at the Cyp2a5 proximal promoter. In conclusion, PGC-1{alpha} mediates the expression of CYP2A5 induced by cAMP in mouse hepatocytes through coactivation of transcription factor HNF-4{alpha}. This strongly suggests that PGC-1{alpha} is the major factor mediating the fasting response of CYP2A5.

  4. Muscle co-activity tuning in Parkinsonian hand movement: disease-specific changes at behavioral and cerebral level.

    PubMed

    van der Stouwe, A M M; Toxopeus, C M; de Jong, B M; Yavuz, P; Valsan, G; Conway, B A; Leenders, K L; Maurits, N M

    2015-01-01

    We investigated simple directional hand movements based on different degrees of muscle co-activity, at behavioral and cerebral level in healthy subjects and Parkinson's disease (PD) patients. We compared "singular" movements, dominated by the activity of one agonist muscle, to "composite" movements, requiring conjoint activity of multiple muscles, in a center-out (right hand) step-tracking task. Behavioral parameters were obtained by EMG and kinematic recordings. fMRI was used to investigate differences in underlying brain activations between PD patients (N = 12) and healthy (age-matched) subjects (N = 18). In healthy subjects, composite movements recruited the striatum and cortical areas comprising bilaterally the supplementary motor area and premotor cortex, contralateral medial prefrontal cortex, primary motor cortex, primary visual cortex, and ipsilateral superior parietal cortex. Contrarily, the ipsilateral cerebellum was more involved in singular movements. This striking dichotomy between striatal and cortical recruitment vs. cerebellar involvement was considered to reflect the complementary roles of these areas in motor control, in which the basal ganglia are involved in movement selection and the cerebellum in movement optimization. Compared to healthy subjects, PD patients showed decreased activation of the striatum and cortical areas in composite movement, while performing worse at behavioral level. This implies that PD patients are especially impaired on tasks requiring highly tuned muscle co-activity. Singular movement, on the other hand, was characterized by a combination of increased activation of the ipsilateral parietal cortex and left cerebellum. As singular movement performance was only slightly compromised, we interpret this as a reflection of increased visuospatial processing, possibly as a compensational mechanism. PMID:26300761

  5. RAC3 more than a nuclear receptor coactivator: a key inhibitor of senescence that is downregulated in aging

    PubMed Central

    Fernández Larrosa, P N; Ruíz Grecco, M; Mengual Gómez, D; Alvarado, C V; Panelo, L C; Rubio, M F; Alonso, D F; Gómez, D E; Costas, M A

    2015-01-01

    Receptor-associated coactivator 3 (RAC3) is a nuclear receptor coactivator usually overexpressed in tumors that exerts oncogenic functions in the cytoplasm and the nucleus. Although as part of its oncogenic actions it was previously identified as an inhibitor of apoptosis and autophagy, its expression is required in order to preserve the pluripotency and embryonic stem cell self-renewal. In this work we investigated its role in cellular senescence. We found that RAC3 overexpression in the nontumoral HEK293 cells inhibits the premature senescence induced by hydrogen peroxide or rapamycin. The mechanism involves not only the inhibition of autophagy early induced by these stimuli in the pathway to senescence, but also the increase in levels and nuclear localization of both the cell cycle suppressors p53/p21 and the longevity promoters FOXO1A, FOXO3A and SIRT1. Furthermore, we found that RAC3 overexpression is required in order to maintain the telomerase activity. In tumoral HeLa cells its activity was inhibited by depletion of RAC3 inducing replicative senescence. Moreover, we demonstrated that in vivo, levels of RAC3 are downregulated in the liver from aged as compared with young rats, whereas the levels of p21 are increased, correlating with the expected senescent cell contents in aged tissues. A similar downregulation of RAC3 was observed in the premature and replicative senescence of human fetal WI-38 cells and premature senescence of hepatocyte HepG2 cell line. Taken together, all these results demonstrate that RAC3 is an inhibitor of senescence whose downregulation in aged individuals could be probably a tumor suppressor mechanism, avoiding the clonal expansion of risky old cells having damaged DNA. PMID:26469953

  6. Activation of a PGC-1-related coactivator (PRC)-dependent inflammatory stress program linked to apoptosis and premature senescence.

    PubMed

    Gleyzer, Natalie; Scarpulla, Richard C

    2013-03-22

    PGC-1-related coactivator (PRC), a growth-regulated member of the PGC-1 coactivator family, contributes to the expression of the mitochondrial respiratory apparatus. PRC also orchestrates a robust response to metabolic stress by promoting the expression of multiple genes specifying inflammation, proliferation, and metabolic reprogramming. Here, we demonstrate that this PRC-dependent stress program is activated during apoptosis and senescence, two major protective mechanisms against cellular dysfunction. Both PRC and its targets (IL1α, SPRR2D, and SPRR2F) were rapidly induced by menadione, an agent that promotes apoptosis through the generation of intracellular oxidants. Menadione-induced apoptosis and the PRC stress program were blocked by the antioxidant N-acetylcysteine. The PRC stress response was also activated by the topoisomerase I inhibitor 7-ethyl-10-hydroxycamptothecin (SN-38), an inducer of premature senescence in tumor cells. Cells treated with SN-38 displayed morphological characteristics of senescence and express senescence-associated β-galactosidase activity. In contrast to menadione, the SN-38 induction of the PRC program occurred over an extended time course and was antioxidant-insensitive. The potential adaptive function of the PRC stress response was investigated by treating cells with meclizine, a drug that promotes glycolytic energy metabolism and has been linked to cardio- and neuroprotection against ischemia-reperfusion injury. Meclizine increased lactate production and was a potent inducer of the PRC stress program, suggesting that PRC may contribute to the protective effects of meclizine. Finally, c-MYC and PRC were coordinately induced under all conditions tested, implicating c-MYC in the biological response to metabolic stress. The results suggest a general role for PRC in the adaptive response to cellular dysfunction. PMID:23364789

  7. Muscle co-activity tuning in Parkinsonian hand movement: disease-specific changes at behavioral and cerebral level

    PubMed Central

    van der Stouwe, A. M. M.; Toxopeus, C. M.; de Jong, B. M.; Yavuz, P.; Valsan, G.; Conway, B. A.; Leenders, K. L.; Maurits, N. M.

    2015-01-01

    We investigated simple directional hand movements based on different degrees of muscle co-activity, at behavioral and cerebral level in healthy subjects and Parkinson's disease (PD) patients. We compared “singular” movements, dominated by the activity of one agonist muscle, to “composite” movements, requiring conjoint activity of multiple muscles, in a center-out (right hand) step-tracking task. Behavioral parameters were obtained by EMG and kinematic recordings. fMRI was used to investigate differences in underlying brain activations between PD patients (N = 12) and healthy (age-matched) subjects (N = 18). In healthy subjects, composite movements recruited the striatum and cortical areas comprising bilaterally the supplementary motor area and premotor cortex, contralateral medial prefrontal cortex, primary motor cortex, primary visual cortex, and ipsilateral superior parietal cortex. Contrarily, the ipsilateral cerebellum was more involved in singular movements. This striking dichotomy between striatal and cortical recruitment vs. cerebellar involvement was considered to reflect the complementary roles of these areas in motor control, in which the basal ganglia are involved in movement selection and the cerebellum in movement optimization. Compared to healthy subjects, PD patients showed decreased activation of the striatum and cortical areas in composite movement, while performing worse at behavioral level. This implies that PD patients are especially impaired on tasks requiring highly tuned muscle co-activity. Singular movement, on the other hand, was characterized by a combination of increased activation of the ipsilateral parietal cortex and left cerebellum. As singular movement performance was only slightly compromised, we interpret this as a reflection of increased visuospatial processing, possibly as a compensational mechanism. PMID:26300761

  8. PIAS1 binds p300 and behaves as a coactivator or corepressor of the transcription factor c-Myb dependent on SUMO-status.

    PubMed

    Ledsaak, Marit; Bengtsen, Mads; Molværsmyr, Ann-Kristin; Fuglerud, Bettina Maria; Matre, Vilborg; Eskeland, Ragnhild; Gabrielsen, Odd Stokke

    2016-05-01

    The PIAS proteins (Protein Inhibitor of Activated STATs) constitute a family of multifunctional nuclear proteins operating as SUMO E3 ligases and being involved in a multitude of interactions. They participate in a range of biological processes, also beyond their well-established role in the immune system and cytokine signalling. They act both as transcriptional corepressors and coactivators depending on the context. In the present work, we investigated mechanisms by which PIAS1 causes activation or repression of c-Myb dependent target genes. Analysis of global expression data shows that c-Myb and PIAS1 knockdowns affect a subset of common targets, but with a dual outcome consistent with a role of PIAS1 as either a corepressor or coactivator. Our mechanistic studies show that PIAS1 engages in a novel interaction with the acetyltransferase and coactivator p300. Interaction and ChIP analysis suggest a bridging function where PIAS1 enhances p300 recruitment to c-Myb-bound sites through interaction with both proteins. In addition, the E3 activity of PIAS1 enhances further its coactivation. Remarkably, the SUMO status of c-Myb had a decisive role, indicating a SUMO-dependent switch in the way PIAS1 affects c-Myb, either as a coactivator or corepressor. Removal of the two major SUMO-conjugation sites in c-Myb (2KR mutant), which enhances its activity significantly, turned PIAS1 into a corepressor. Also, p300 was less efficiently recruited to chromatin by c-Myb-2KR. We propose that PIAS1 acts as a "protein inhibitor of activated c-Myb" in the absence of SUMOylation while, in its presence, PIAS behaves as a "protein activator of repressed c-Myb". PMID:27032383

  9. GENERAL CONTROL NONREPRESSED PROTEIN5-Mediated Histone Acetylation of FERRIC REDUCTASE DEFECTIVE3 Contributes to Iron Homeostasis in Arabidopsis1

    PubMed Central

    Xing, Jiewen; Wang, Tianya; Liu, Zhenshan; Xu, Jianqin; Yao, Yingyin; Hu, Zhaorong; Peng, Huiru; Xin, Mingming; Yu, Futong; Zhou, Daoxiu; Ni, Zhongfu

    2015-01-01

    Iron homeostasis is essential for plant growth and development. Here, we report that a mutation in GENERAL CONTROL NONREPRESSED PROTEIN5 (GCN5) impaired iron translocation from the root to the shoot in Arabidopsis (Arabidopsis thaliana). Illumina high-throughput sequencing revealed 879 GCN5-regulated candidate genes potentially involved in iron homeostasis. Chromatin immunoprecipitation assays indicated that five genes (At3G08040, At2G01530, At2G39380, At2G47160, and At4G05200) are direct targets of GCN5 in iron homeostasis regulation. Notably, GCN5-mediated acetylation of histone 3 lysine 9 and histone 3 lysine 14 of FERRIC REDUCTASE DEFECTIVE3 (FRD3) determined the dynamic expression of FRD3. Consistent with the function of FRD3 as a citrate efflux protein, the iron retention defect in gcn5 was rescued and fertility was partly restored by overexpressing FRD3. Moreover, iron retention in gcn5 roots was significantly reduced by the exogenous application of citrate. Collectively, these data suggest that GCN5 plays a critical role in FRD3-mediated iron homeostasis. Our results provide novel insight into the chromatin-based regulation of iron homeostasis in Arabidopsis. PMID:26002909

  10. Why do adult dogs 'play'?

    PubMed

    Bradshaw, John W S; Pullen, Anne J; Rooney, Nicola J

    2015-01-01

    Among the Carnivora, play behaviour is usually made up of motor patterns characteristic of predatory, agonistic and courtship behaviour. Domestic dogs are unusual in that play is routinely performed by adults, both socially, with conspecifics and with humans, and also asocially, with objects. This enhanced playfulness is commonly thought to be a side effect of paedomorphosis, the perpetuation of juvenile traits into adulthood, but here we suggest that the functions of the different types of play are sufficiently distinct that they are unlikely to have arisen through a single evolutionary mechanism. Solitary play with objects appears to be derived from predatory behaviour: preferred toys are those that can be dismembered, and a complex habituation-like feedback system inhibits play with objects that are resistant to alteration. Intraspecific social play is structurally different from interspecific play and may therefore be motivationally distinct and serve different goals; for example, dogs often compete over objects when playing with other dogs, but are usually more cooperative when the play partner is human. The majority of dogs do not seem to regard competitive games played with a human partner as "dominance" contests: rather, winning possession of objects during games appears to be simply rewarding. Play may be an important factor in sociality, since dogs are capable of extracting social information not only from games in which they participate, but also from games that they observe between third parties. We suggest that the domestic dog's characteristic playfulness in social contexts is an adaptive trait, selected during domestication to facilitate both training for specific purposes, and the formation of emotionally-based bonds between dog and owner. Play frequency and form may therefore be an indicator of the quality of dog-owner relationships. PMID:25251020

  11. Thinking about Children's Play: Play Is Not Work, Nor Is Work Play.

    ERIC Educational Resources Information Center

    Elkind, David

    2001-01-01

    Addresses the concept of "play as a child's work," from the viewpoints of Montessori, Freud, and Piaget. Contends that children's play: (1) like adult play, may be individual or social; (2) has immediate value for the child as a way of expressing feelings; and (3) is a healthy counterpoise to work. (SD)

  12. Playing with the Multiple Intelligences: How Play Helps Them Grow

    ERIC Educational Resources Information Center

    Eberle, Scott G.

    2011-01-01

    Howard Gardner first posited a list of "multiple intelligences" as a liberating alternative to the assumptions underlying traditional IQ testing in his widely read study "Frames of Mind" (1983). Play has appeared only in passing in Gardner's thinking about intelligence, however, even though play instructs and trains the verbal, interpersonal,…

  13. Understanding Young Children's Learning through Play: Building Playful Pedagogies

    ERIC Educational Resources Information Center

    Broadhead, Pat; Burt, Andy

    2011-01-01

    This timely and accessible text introduces, theorises and practically applies two important concepts which now underpin early years practice: those of "playful learning" and "playful pedagogies". Pat Broadhead and Andy Burt draw upon filmed material, conversations with children, reflection, observation, and parental and staff interviews, in their…

  14. Well Played: The Origins and Future of Playfulness

    ERIC Educational Resources Information Center

    Gordon, Gwen

    2014-01-01

    In this article, the author synthesizes research from several disciplines to shed light on play's central role in healthy development. Gordon builds on research in attachment theory that correlates secure attachment in infancy with adult well-being to demonstrate how playfulness might be a lifelong outcome of secure attachment and a primary…

  15. "Play for Real": Understanding Middle School Children's Dramatic Play.

    ERIC Educational Resources Information Center

    Sierra, Zayda

    2000-01-01

    Summarizes a dissertation that examines the theory and practice of dramatic play among middle school children. Finds that they are still adept and interested in dramatic play. Discusses four components describing the nature and product of the dramatic process (social interactions, metacognitive strategies, ideational processes, and content of…

  16. Playing To Get Smart. Viewpoint.

    ERIC Educational Resources Information Center

    Jones, Elizabeth

    2003-01-01

    Asserts that it is through play with materials and relationships, invention of classification systems, and solving problems in dialogue with others that young children develop the basic skills they will need to become effective contributors to the health of a changing world. Offers suggestions for teaching children play skills by providing…

  17. The Child's Right To Play.

    ERIC Educational Resources Information Center

    Guddemi, Marcy

    Several factors are eroding children's right to play. The first is continuing poverty throughout the world. This factor is evident in underdeveloped countries and the inner cities of industrialized countries. Changing cultural values are a second factor in developed societies where indifference toward the importance of play is prevalent. The many…

  18. Sand and Water Table Play

    ERIC Educational Resources Information Center

    Wallace, Ann H.; White, Mary J.; Stone, Ryan

    2010-01-01

    The authors observed preschoolers engaged at the sand and water table to determine if math could be found within their play. Wanting to understand how children interact with provided materials and what kinds of math ideas they explore during these interactions, the authors offer practical examples of how such play can promote mathematical…

  19. Young Children and War Play.

    ERIC Educational Resources Information Center

    Carlsson-Paige, Nancy; Levin, Diane E.

    1988-01-01

    In a recent survey of parents and early childhood professionals the prevalence of war play among children and an increase in the amount of violence in children's play was noted. Outlines how the deregulation of children's television during the Reagan administration has affected children's exposure to violence in children's television programming.…

  20. Invention at Play. Educators' Manual.

    ERIC Educational Resources Information Center

    Judd, Michael; Lacasse, Jane; Smith, Monica; Reilly, Katie

    A Smithsonian exhibition was developed that looked at invention in an innovative way. It aimed to encourage visitors to make connections between their own lives and abilities and those of inventors. The role of play in the invention process was examined. Play is a universal and familiar activity and can help people find the link between their own…

  1. The Play of Socratic Dialogue

    ERIC Educational Resources Information Center

    Smith, Richard

    2011-01-01

    Proponents of philosophy for children generally see themselves as heirs to the "Socratic" tradition. They often claim too that children's aptitude for play leads them naturally to play with abstract, philosophical ideas. However in Plato's dialogues we find in the mouth of "Socrates" many warnings against philosophising with the young. Those…

  2. Playground Play: Educational and Inclusive

    ERIC Educational Resources Information Center

    Moore, Lisa

    2011-01-01

    It is easy to understand that fun is one of the key ingredients to any playground activity. But what one may not realize is that play systems--including slides, tunnels, activity panels, and more--encourage a lot more than just fun: there is learning at work in playground play, as well as the opportunity to include children of all abilities in…

  3. Empowering Groups that Enable Play

    ERIC Educational Resources Information Center

    Wilson, David Sloan; Marshall, Danielle; Iserhott, Hindi

    2011-01-01

    Creating play environments for children usually requires groups of adults working together. An extensive scientific literature describes how groups function to achieve shared goals in general terms, and groups attempting to empower play may find this literature useful. Design principles for managing natural resources, identified by Elinor Ostrom…

  4. Let's Play Three on Three!

    ERIC Educational Resources Information Center

    Kern, Jack; Calleja, Paul

    2008-01-01

    Over the course of nine years as a supervisor of intern teachers, the first author collected observations of game play during lessons taught by intern teachers or their mentors. In general, the observations indicated that the majority of students got limited practice opportunities during game play. A close look at the data revealed an interesting…

  5. Outdoor Play: Combating Sedentary Lifestyles

    ERIC Educational Resources Information Center

    Thigpen, Betsy

    2007-01-01

    Increasingly sedentary lifestyles are contributing to overweight and other health concerns as children spend less and less time outside engaged in active play. Outdoor play provides important opportunities to explore the natural world, interact with peers, engage in vigorous physical activity, and learn about our environment. However, outdoor…

  6. The Fractal Self at Play

    ERIC Educational Resources Information Center

    Marks-Tarlow, Terry

    2010-01-01

    In this article, the author draws on contemporary science to illuminate the relationship between early play experiences, processes of self-development, and the later emergence of the fractal self. She argues that orientation within social space is a primary function of early play and developmentally a two-step process. With other people and with…

  7. A Place for Block Play.

    ERIC Educational Resources Information Center

    Moore, Gary T.

    1997-01-01

    Discusses the importance of block play--including its contributions to perceptual, fine motor, and cognitive development--and components of a good preschool block play area. Recommends unit blocks complemented by stacking blocks, toys, beads, cubes, and Brio wooden toys. Makes recommendations for space, size, locations and connections to other…

  8. Niger Delta play types, Nigeria

    SciTech Connect

    Akinpelu, A.O.

    1995-08-01

    Exploration databases can be more valuable when sorted by play type. Play specific databases provide a system to organize E & P data used in evaluating the range of values of parameters for reserve estimation and risk assessment. It is important both in focusing the knowledge base and in orienting research effort. A play in this context is any unique combination of trap, reservoir and source properties with the right dynamics of migration and preservation that results in hydrocarbon accumulation. This definitions helps us to discriminate the subtle differences found with these accumulation settings. About 20 play types were identified around the Niger Delta oil province in Nigeria. These are grouped into three parts: (1) The proven plays-constituting the bulk of exploration prospects in Nigeria today. (2) The unproven or semi-proven plays usually with some successes recorded in a few tries but where knowledge is still inadequate. (3) The unproven or analogous play concept. These are untested but geologically sound ideas which may or may not have been tried elsewhere. With classification and sub grouping of these play types into specific databases, intrinsic attributes and uniqueness of each of them with respect to the four major risk elements and the eight parameters for reserve estimation can be better understood.

  9. Play Therapy with Special Populations.

    ERIC Educational Resources Information Center

    Carmichael, Karla D.

    This paper notes that therapists often feel unqualified to deal with special populations of children because of a lack of understanding of the universalness of play therapy. Suggestions are offered for beginning play therapists who may work with a number of special populations of children. It is recommended that the social learning approach to…

  10. Making Play Work for Education

    ERIC Educational Resources Information Center

    Weisberg, Deena Skolnick; Kittredge, Audrey K.; Hirsh-Pasek, Kathy; Golinkoff, Roberta Michnick; Klahr, David

    2015-01-01

    Children, especially in the preschool years, learn a tremendous amount through play. Research on guided play demonstrates how schools can couple a curriculum-centered preschool program with a developmentally appropriate pedagogical approach to classroom teaching. However, to fully test this claim, we need a clear definition of the term…

  11. Solitary Play: Some Functional Reconsiderations

    ERIC Educational Resources Information Center

    Moore, Nancy V.; And Others

    1974-01-01

    Solitary play in six kindergarten children was observed and coded for frequency and type in order to resolve iscrepancies in a Sex Birth Order interaction. Several facts concerning solitary play as indicative of independence and maturity are noted. (Author/ED)

  12. Engaging Families through Artful Play

    ERIC Educational Resources Information Center

    Brown, Robert

    2015-01-01

    This paper explores how aligned arts and play experiences can extend child and family engagement in a public outdoor space. The importance of outdoor play for children is strongly advocated and in response local governments provide playgrounds and recreational open spaces. To extend further the experiences afforded in such spaces some local…

  13. Three Plays from the Japanese.

    ERIC Educational Resources Information Center

    Mayfield, M. Kent

    This study is both an interpretation and a translation of three modern Japanese plays, providing an artistic perspective on the radical reordering of experience and thought with which modern man must grapple in cross-cultural encounters. An introductory essay prefaces each play, providing a historical, critical, or appreciative perspective from…

  14. Principles of Play for Soccer

    ERIC Educational Resources Information Center

    Ouellette, John

    2004-01-01

    Soccer coaches must understand the principles of play if they want to succeed. The principles of play are the rules of action that support the basic objectives of soccer and the foundation of a soccer coaching strategy. They serve as a set of permanent criteria that coaches can use to evaluate the efforts of their team. In this article, the author…

  15. Transmedia Play: Literacy across Media

    ERIC Educational Resources Information Center

    Alper, Meryl; Herr-Stephenson, Rebecca

    2013-01-01

    Transmedia play is a new way to understand how children develop critical media literacy and new media literacies through their interactions with contemporary media that links stories and structures across platforms. This essay highlights five characteristics of transmedia play that make it particularly useful for learning:…

  16. Neuroscience, Play, and Child Development.

    ERIC Educational Resources Information Center

    Frost, Joe L.

    This paper presents a brief overview of the array of neuroscience research as it applies to play and child development. The paper discusses research showing the importance of play for brain growth and child development, and recommends that families, schools and other social and corporate institutions rearrange their attitudes and priorities about…

  17. Playful biometrics: controversial technology through the lens of play.

    PubMed

    Ellerbrok, Ariane

    2011-01-01

    This article considers the role of play in the context of technological emergence and expansion, particularly as it relates to recently emerging surveillance technologies. As a case study, I consider the trajectory of automated face recognition—a biometric technology of numerous applications, from its more controversial manifestations under the rubric of national security to a clearly emerging orientation toward play. This shift toward “playful” biometrics—or from a technology traditionally coded as “hard” to one now increasingly coded as “soft”—is critical insofar as it renders problematic the traditional modes of critique that have, up until this point, challenged the expansion of biometric systems into increasingly ubiquitous realms of everyday life. In response to this dynamic, I propose theorizing the expansion of face recognition specifically in relation to “play,” a step that allows us to broaden the critical space around newly emerging playful biometrics, as well as playful surveillance more generally. In addition, play may also have relevance for theorizing other forms of controversial technology, particularly given its potential role in processes of obfuscation, normalization, and marginalization. PMID:22175066

  18. Pituitary adenylate cyclase-activating peptide induces long-lasting neuroprotection through the induction of activity-dependent signaling via the cyclic AMP response element-binding protein-regulated transcription co-activator 1

    PubMed Central

    Baxter, Paul S; Martel, Marc-Andre; McMahon, Aoife; Kind, Peter C; Hardingham, Giles E

    2011-01-01

    Pituitary adenylate cyclase-activating peptide (PACAP) is a neuroprotective peptide which exerts its effects mainly through the cAMP-protein kinase A (PKA) pathway. Here, we show that in cortical neurons, PACAP-induced PKA signaling exerts a major part of its neuroprotective effects indirectly, by triggering action potential (AP) firing. Treatment of cortical neurons with PACAP induces a rapid and sustained PKA-dependent increase in AP firing and associated intracellular Ca2+ transients, which are essential for the anti-apoptotic actions of PACAP. Transient exposure to PACAP induces long-lasting neuroprotection in the face of apoptotic insults which is reliant on AP firing and the activation of cAMP response element (CRE) binding protein (CREB)-mediated gene expression. Although direct, activity-independent PKA signaling is sufficient to trigger phosphorylation on CREB’s activating serine-133 site, this is insufficient for activation of CREB-mediated gene expression. Full activation is dependent on CREB-regulated transcription co-activator 1 (CRTC1), whose PACAP-induced nuclear import is dependent on firing activity-dependent calcineurin signaling. Over-expression of CRTC1 is sufficient to rescue PACAP-induced CRE-mediated gene expression in the face of activity-blockade, while dominant negative CRTC1 interferes with PACAP-induced, CREB-mediated neuroprotection. Thus, the enhancement of AP firing may play a significant role in the neuroprotective actions of PACAP and other adenylate cyclase-coupled ligands. PMID:21623792

  19. Up-regulation of the Sirtuin 1 (Sirt1) and Peroxisome Proliferator-activated Receptor γ Coactivator-1α (PGC-1α) Genes in White Adipose Tissue of Id1 Protein-deficient Mice

    PubMed Central

    Zhao, Ying; Ling, Flora; Griffin, Timothy M.; He, Ting; Towner, Rheal; Ruan, Hong; Sun, Xiao-Hong

    2014-01-01

    Id1, a helix-loop-helix (HLH) protein that inhibits the function of basic HLH E protein transcription factors in lymphoid cells, has been implicated in diet- and age-induced obesity by unknown mechanisms. Here we show that Id1-deficient mice are resistant to a high fat diet- and age-induced obesity, as revealed by reduced weight gain and body fat, increased lipid oxidation, attenuated hepatosteatosis, lower levels of lipid droplets in brown adipose tissue, and smaller white adipocytes after a high fat diet feeding or in aged animals. Id1 deficiency improves glucose tolerance, lowers serum insulin levels, and reduces TNFα gene expression in white adipose tissue. Id1 deficiency also increased expression of Sirtuin 1 and peroxisome proliferator-activated receptor γ coactivator 1α, regulators of mitochondrial biogenesis and energy expenditure, in the white adipose tissue. This effect was accompanied by the elevation of several genes encoding proteins involved in oxidative phosphorylation and fatty acid oxidation, such as cytochrome c, medium-chain acyl-CoA dehydrogenase, and adipocyte protein 2. Moreover, the phenotype for Id1 deficiency was similar to that of mice expressing an E protein dominant-positive construct, ET2, suggesting that the balance between Id and E proteins plays a role in regulating lipid metabolism and insulin sensitivity. PMID:25190816

  20. ICAT Inhibits beta-Catenin Binding to Tcf/Lef-Family Transcription Factors and in the General Coactivator p300 Using Independent Structural Modules

    SciTech Connect

    Daniels, D. L.

    2002-01-01

    In the canonical Wnt signaling pathway, {beta}-catenin activates target genes through its interactions with Tcf/Lef-family transcription factors and additional transcriptional coactivators. The crystal structure of ICAT, an inhibitor of {beta}-catenin-mediated transcription, bound to the armadillo repeat domain of {beta}-catenin, has been determined. ICAT contains an N-terminal helilical domain that binds to repeats 11 and 12 of {beta}-catenin, and an extended C-terminal region that binds to repeats 5-10 in a manner similar that of Tcfs and other {beta}-catenin ligands. Full-length ICAT dissociates complexes of {beta}-catenin, Lef-1, and the transcriptional coactivator p300, whereas the helical domain alone selectively blocks binding to p300. The C-terminal armadillo repeats of {beta}-catenin may be an attractive target for compounds designed to disrupt aberrant {beta}-catenin-mediated transcription associated with various cancers.

  1. Seizures induced by playing music.

    PubMed

    Sutherling, W W; Hershman, L M; Miller, J Q; Lee, S I

    1980-09-01

    A 67-year-old organist and minister with diabetes mellitus had stereotyped focal seizures of the left lower face, jaw, and neck. Attacks occurred spontaneously or were induced when he played a specific hymn on the organ. The seizures were not induced by reading, singing, hearing, or playing the hymn silently. The patient had interictal weakness of the left lower face and left side of the tongue. Focal seizures were recorded on an electroencephalogram (EEG) at the right temporofrontal area. This patient illustrates partial seizures induced by playing music. PMID:6775246

  2. The RNA binding complexes NF45-NF90 and NF45-NF110 associate dynamically with the c-fos gene and function as transcriptional coactivators.

    PubMed

    Nakadai, Tomoyoshi; Fukuda, Aya; Shimada, Miho; Nishimura, Ken; Hisatake, Koji

    2015-10-30

    The c-fos gene is rapidly induced to high levels by various extracellular stimuli. We used a defined in vitro transcription system that utilizes the c-fos promoter to purify a coactivator activity in an unbiased manner. We report here that NF45-NF90 and NF45-NF110, which possess archetypical double-stranded RNA binding motifs, have a direct function as transcriptional coactivators. The transcriptional activities of the nuclear factor (NF) complexes (NF45-NF90 and NF45-NF110) are mediated by both the upstream enhancer and core promoter regions of the c-fos gene and do not require their double-stranded RNA binding activities. The NF complexes cooperate with general coactivators, PC4 and Mediator, to elicit a high level of transcription and display multiple interactions with activators and the components of the general transcriptional machinery. Knockdown of the endogenous NF90/NF110 in mouse cells shows an important role for the NF complexes in inducing c-fos transcription. Chromatin immunoprecipitation assays demonstrate that the NF complexes occupy the c-fos enhancer/promoter region before and after serum induction and that their occupancies within the coding region of the c-fos gene increase in parallel to that of RNAPII upon serum induction. In light of their dynamic occupancy on the c-fos gene as well as direct functions in both transcription and posttranscriptional processes, the NF complexes appear to serve as multifunctional coactivators that coordinate different steps of gene expression to facilitate rapid response of inducible genes. PMID:26381409

  3. Enhancer of Acetyltransferase Chameau (EAChm) Is a Novel Transcriptional Co-Activator

    PubMed Central

    Imamura, Yuko; Higashi, Miki; Yoneda, Mitsuhiro; Ito, Takashi

    2015-01-01

    Acetylation of nucleosomal histones by diverse histone acetyltransferases (HAT) plays pivotal roles in many cellular events. Discoveries of novel HATs and HAT related factors have provided new insights to understand the roles and mechanisms of histone acetylation. In this study, we identified prominent Histone H3 acetylation activity in vitro and purified its activity, showing that it is composed of the MYST acetyltransferase Chameau and Enhancer of the Acetyltransferase Chameau (EAChm) family. EAChm is a negatively charged acidic protein retaining aspartate and glutamate. Furthermore, we identified that Chameau and EAChm stimulate transcription in vitro together with purified general transcription factors. In addition, RNA-seq analysis of Chameu KD and EAChm KD S2 cells suggest that Chameau and EAChm regulate transcription of common genes in vivo. Our results suggest that EAChm regulates gene transcription in Drosophila embryos by enhancing Acetyltransferase Chameau activity. PMID:26555228

  4. Self-playing musical instrument

    NASA Astrophysics Data System (ADS)

    Bouffard, Karen

    2001-05-01

    This do-ahead Physics Olympics competition is a musical challenge based on one designed by Dan Calder for a past New Hampshire Physics Olympics. The objective is to build a musical instrument that is self-playing.

  5. The Many Faces of Play.

    ERIC Educational Resources Information Center

    Werth, Louise H.

    1984-01-01

    Presents descriptions of play reflecting recent theories, including the psychoanalytic works of Freud, Erikson, and Peller; Piaget's developmental theory (with discussion of Sutton-Smith); and the views of Smilansky and Parten. (AS)

  6. A multiverse play divides opinion

    NASA Astrophysics Data System (ADS)

    Crease, Robert P.

    2015-03-01

    The stage lights rise. A man and woman meet in a cute way - "Do you know why it's impossible to lick the tips of your elbows?" she asks - they chat momentarily, and separate. The play is Constellations by Nick Payne.

  7. Chromatin, TAFs, and a novel multiprotein coactivator are required for synergistic activation by Sp1 and SREBP-1a in vitro.

    PubMed

    Näär, A M; Beaurang, P A; Robinson, K M; Oliner, J D; Avizonis, D; Scheek, S; Zwicker, J; Kadonaga, J T; Tjian, R

    1998-10-01

    The promoter selectivity factor Sp1 often cooperates with other enhancer-binding proteins to activate transcription. To study the molecular underpinnings of these regulatory events, we have reconstituted in vitro the synergy observed in vivo between Sp1 and the sterol-regulated factor SREBP-1a at the low density lipoprotein receptor (LDLR) promoter. Using a highly purified human transcription system, we found that chromatin, TAFs, and a novel SREBP-binding coactivator activity, which includes CBP, are all required to mediate full synergistic activation by Sp1 and SREBP-1a. The SREBP-binding domain of CBP inhibits activation by SREBP-1a and Sp1 in a dominant-negative fashion that is both chromatin- and activator-specific. Whereas recombinant CBP alone is not sufficient to mediate activation, a human cellular fraction containing CBP can support high levels of chromatin-dependent synergistic activation. Purification of this activity to near homogeneity resulted in the identification of a multiprotein coactivator, including CBP, that selectively binds to the SREBP-1a activation domain and is capable of mediating high levels of synergistic activation by SREBP/Sp1 on chromatin templates. The development of a reconstituted chromatin transcription system has allowed us to isolate a novel coactivator that is recruited by the SREBP-1a activation domain and that functions in concert with TFIID to coordinate the action of multiple activators at complex promoters in the context of chromatin. PMID:9765204

  8. The genomic context and co-recruitment of SP1 affect ERRα co-activation by PGC-1α in muscle cells

    PubMed Central

    Baresic, Mario; van Nimwegen, Erik; Handschin, Christoph

    2016-01-01

    The peroxisome proliferator-activated receptor γ co-activator 1α (PGC-1α) coordinates the transcriptional network response to promote an improved endurance capacity in skeletal muscle, e.g. by co-activating the estrogen-related receptor α (ERRα) in the regulation of oxidative substrate metabolism. Despite a close functional relationship, the interaction between these two proteins has not been studied on a genomic level. We now mapped the genome-wide binding of ERRα to DNA in a skeletal muscle cell line with elevated PGC-1α and linked the DNA recruitment to global PGC-1α target gene regulation. We found that, surprisingly, ERRα co-activation by PGC-1α is only observed in the minority of all PGC-1α recruitment sites. Nevertheless, a majority of PGC-1α target gene expression is dependent on ERRα. Intriguingly, the interaction between these two proteins is controlled by the genomic context of response elements, in particular the relative GC and CpG content, monomeric and dimeric repeat binding site configuration for ERRα, and adjacent recruitment of the transcription factor SP1. These findings thus not only reveal a novel insight into the regulatory network underlying muscle cell plasticity, but also strongly link the genomic context of DNA response elements to control transcription factor – co-regulator interactions. PMID:27182621

  9. Relaxin activates peroxisome proliferator-activated receptor γ (PPARγ) through a pathway involving PPARγ coactivator 1α (PGC1α).

    PubMed

    Singh, Sudhir; Simpson, Ronda L; Bennett, Robert G

    2015-01-01

    Relaxin activation of its receptor RXFP1 triggers multiple signaling pathways. Previously, we have shown that relaxin activates PPARγ transcriptional activity in a ligand-independent manner, but the mechanism for this effect was unknown. In this study, we examined the signaling pathways of downstream of RXFP1 leading to PPARγ activation. Using cells stably expressing RXFP1, we found that relaxin regulation of PPARγ activity requires accumulation of cAMP and subsequent activation of cAMP-dependent protein kinase (PKA). The activated PKA subsequently phosphorylated cAMP response element-binding protein (CREB) at Ser-133 to activate it directly, as well as indirectly through mitogen activated protein kinase p38 MAPK. Activated CREB was required for relaxin stimulation of PPARγ activity, while there was no evidence for a role of the nitric oxide or ERK MAPK pathways. Relaxin increased the mRNA and protein levels of the coactivator protein PGC1α, and this effect was dependent on PKA, and was completely abrogated by a dominant-negative form of CREB. This mechanism was confirmed in a hepatic stellate cell line stably that endogenously expresses RXFP1. Reduction of PGC1α levels using siRNA diminished the regulation of PPARγ by relaxin. These results suggest that relaxin activates the cAMP/PKA and p38 MAPK pathways to phosphorylate CREB, resulting in increased PGC1α levels. This provides a mechanism for the ligand-independent activation of PPARγ in response to relaxin. PMID:25389293

  10. Relaxin Activates Peroxisome Proliferator-activated Receptor γ (PPARγ) through a Pathway Involving PPARγ Coactivator 1α (PGC1α)*

    PubMed Central

    Singh, Sudhir; Simpson, Ronda L.; Bennett, Robert G.

    2015-01-01

    Relaxin activation of its receptor RXFP1 triggers multiple signaling pathways. Previously, we have shown that relaxin activates PPARγ transcriptional activity in a ligand-independent manner, but the mechanism for this effect was unknown. In this study, we examined the signaling pathways of downstream of RXFP1 leading to PPARγ activation. Using cells stably expressing RXFP1, we found that relaxin regulation of PPARγ activity requires accumulation of cAMP and subsequent activation of cAMP-dependent protein kinase (PKA). The activated PKA subsequently phosphorylated cAMP response element-binding protein (CREB) at Ser-133 to activate it directly, as well as indirectly through mitogen activated protein kinase p38 MAPK. Activated CREB was required for relaxin stimulation of PPARγ activity, while there was no evidence for a role of the nitric oxide or ERK MAPK pathways. Relaxin increased the mRNA and protein levels of the coactivator protein PGC1α, and this effect was dependent on PKA, and was completely abrogated by a dominant-negative form of CREB. This mechanism was confirmed in a hepatic stellate cell line stably that endogenously expresses RXFP1. Reduction of PGC1α levels using siRNA diminished the regulation of PPARγ by relaxin. These results suggest that relaxin activates the cAMP/PKA and p38 MAPK pathways to phosphorylate CREB, resulting in increased PGC1α levels. This provides a mechanism for the ligand-independent activation of PPARγ in response to relaxin. PMID:25389293

  11. The transcriptional coactivator PGC1α protects against hyperthermic stress via cooperation with the heat shock factor HSF1.

    PubMed

    Xu, L; Ma, X; Bagattin, A; Mueller, E

    2016-01-01

    Heat shock proteins (HSPs) are required for the clearance of damaged and aggregated proteins and have important roles in protein homeostasis. It has been shown that the heat shock transcription factor, HSF1, orchestrates the transcriptional induction of these stress-regulated chaperones; however, the coregulatory factors responsible for the enhancement of HSF1 function on these target genes have not been fully elucidated. Here, we demonstrate that the cold-inducible coactivator, PGC1α, also known for its role as a regulator of mitochondrial and peroxisomal biogenesis, thermogenesis and cytoprotection from oxidative stress, regulates the expression of HSPs in vitro and in vivo and modulates heat tolerance. Mechanistically, we show that PGC1α physically interacts with HSF1 on HSP promoters and that cells and mice lacking PGC1α have decreased HSPs levels and are more sensitive to thermal challenges. Taken together, our findings suggest that PGC1α protects against hyperthermia by cooperating with HSF1 in the induction of a transcriptional program devoted to the cellular protection from thermal insults. PMID:26890141

  12. Utility of coactive neuro-fuzzy inference system for pan evaporation modeling in comparison with multilayer perceptron

    NASA Astrophysics Data System (ADS)

    Tabari, Hossein; Hosseinzadeh Talaee, P.; Abghari, Hirad

    2012-05-01

    Estimation of pan evaporation ( E pan) using black-box models has received a great deal of attention in developing countries where measurements of E pan are spatially and temporally limited. Multilayer perceptron (MLP) and coactive neuro-fuzzy inference system (CANFIS) models were used to predict daily E pan for a semi-arid region of Iran. Six MLP and CANFIS models comprising various combinations of daily meteorological parameters were developed. The performances of the models were tested using correlation coefficient ( r), root mean square error (RMSE), mean absolute error (MAE) and percentage error of estimate (PE). It was found that the MLP6 model with the Momentum learning algorithm and the Tanh activation function, which requires all input parameters, presented the most accurate E pan predictions ( r = 0.97, RMSE = 0.81 mm day-1, MAE = 0.63 mm day-1 and PE = 0.58 %). The results also showed that the most accurate E pan predictions with a CANFIS model can be achieved with the Takagi-Sugeno-Kang (TSK) fuzzy model and the Gaussian membership function. Overall performances revealed that the MLP method was better suited than CANFIS method for modeling the E pan process.

  13. Transient α-helices in the disordered RPEL motifs of the serum response factor coactivator MKL1

    NASA Astrophysics Data System (ADS)

    Mizuguchi, Mineyuki; Fuju, Takahiro; Obita, Takayuki; Ishikawa, Mitsuru; Tsuda, Masaaki; Tabuchi, Akiko

    2014-06-01

    The megakaryoblastic leukemia 1 (MKL1) protein functions as a transcriptional coactivator of the serum response factor. MKL1 has three RPEL motifs (RPEL1, RPEL2, and RPEL3) in its N-terminal region. MKL1 binds to monomeric G-actin through RPEL motifs, and the dissociation of MKL1 from G-actin promotes the translocation of MKL1 to the nucleus. Although structural data are available for RPEL motifs of MKL1 in complex with G-actin, the structural characteristics of RPEL motifs in the free state have been poorly defined. Here we characterized the structures of free RPEL motifs using NMR and CD spectroscopy. NMR and CD measurements showed that free RPEL motifs are largely unstructured in solution. However, NMR analysis identified transient α-helices in the regions where helices α1 and α2 are induced upon binding to G-actin. Proline mutagenesis showed that the transient α-helices are locally formed without helix-helix interactions. The helix content is higher in the order of RPEL1, RPEL2, and RPEL3. The amount of preformed structure may correlate with the binding affinity between the intrinsically disordered protein and its target molecule.

  14. Luminescence properties of Ce3+ and Tb3+ co-activated ZnAl2O4 phosphor

    NASA Astrophysics Data System (ADS)

    Tshabalala, K. G.; Cho, S.-H.; Park, J.-K.; Pitale, Shreyas S.; Nagpure, I. M.; Kroon, R. E.; Swart, H. C.; Ntwaeaborwa, O. M.

    2012-05-01

    In this study, a solution combustion method was used to prepare green emitting Ce3+-Tb3+ co-activated ZnAl2O4 phosphor. The samples were annealed at 700 °C in air or hydrogen atmosphere to improve their crystallinity and optical properties. X-ray diffraction study confirmed that both as-prepared and post-preparation annealed samples crystallized in the well known cubic spinel structure of ZnAl2O4. An agglomeration of irregular platelet-like particles whose surfaces were encrusted with smaller spheroidal particles was confirmed by scanning electron microscopy (SEM). The fluorescence data collected from the annealed samples with different concentrations of Ce3+ and Tb3+ show the enhanced green emission at 543 nm associated with 5D4→7F5 transitions of Tb3+. The enhancement was attributed to energy transfer from Ce3+ to Tb3+. Possible mechanism of energy transfer via a down conversion process is discussed. Furthermore, cathodoluminescence (CL) intensity degradation of this phosphor was also investigated and the degradation data suggest that the material was chemically stable and the CL intensity was also stable after 10 h of irradiation by a beam of high energy electrons.

  15. Over-expression of putative transcriptional coactivator KELP interferes with Tomato mosaic virus cell-to-cell movement.

    PubMed

    Sasaki, Nobumitsu; Ogata, Takuya; Deguchi, Masakazu; Nagai, Shoko; Tamai, Atsushi; Meshi, Tetsuo; Kawakami, Shigeki; Watanabe, Yuichiro; Matsushita, Yasuhiko; Nyunoya, Hiroshi

    2009-03-01

    Tomato mosaic virus (ToMV) encodes a movement protein (MP) that is necessary for virus cell-to-cell movement. We have demonstrated previously that KELP, a putative transcriptional coactivator of Arabidopsis thaliana, and its orthologue from Brassica campestris can bind to ToMV MP in vitro. In this study, we examined the effects of the transient over-expression of KELP on ToMV infection and the intracellular localization of MP in Nicotiana benthamiana, an experimental host of the virus. In co-bombardment experiments, the over-expression of KELP inhibited virus cell-to-cell movement. The N-terminal half of KELP (KELPdC), which had been shown to bind to MP, was sufficient for inhibition. Furthermore, the over-expression of KELP and KELPdC, both of which were co-localized with ToMV MP, led to a reduction in the plasmodesmal association of MP. In the absence of MP expression, KELP was localized in the nucleus and the cytoplasm by the localization signal in its N-terminal half. It was also shown that ToMV amplified normally in protoplasts prepared from leaf tissue that expressed KELP transiently. These results indicate that over-expressed KELP interacts with MP in vivo and exerts an inhibitory effect on MP function for virus cell-to-cell movement, but not on virus amplification in individual cells. PMID:19236566

  16. Tale of a multifaceted co-activator, hADA3: from embryogenesis to cancer and beyond.

    PubMed

    Chand, Vaibhav; Nandi, Deeptashree; Mangla, Anita Garg; Sharma, Puneet; Nag, Alo

    2016-09-01

    Human ADA3, the evolutionarily conserved transcriptional co-activator, remains the unified part of multiple cellular functions, including regulation of nuclear receptor functions, cell proliferation, apoptosis, senescence, chromatin remodelling, genomic stability and chromosomal maintenance. The past decade has witnessed exciting findings leading to considerable expansion in research related to the biology and regulation of hADA3. Embryonic lethality in homozygous knockout Ada3 mouse signifies the importance of this gene product during early embryonic development. Moreover, the fact that it is a novel target of Human Papillomavirus E6 oncoprotein, one of the most prevalent causal agents behind cervical cancer, helps highlight some of the crucial aspects of HPV-mediated oncogenesis. These findings imply the central involvement of hADA3 in regulation of various cellular functional losses accountable for the genesis of malignancy and viral infections. Recent reports also provide evidence for post-translational modifications of hADA3 leading to its instability and contributing to the malignant phenotype of cervical cancer cells. Furthermore, its association with poor prognosis of breast cancer suggests intimate association in the pathogenesis of the disease. Here, we present the first review on hADA3 with a comprehensive outlook on the molecular and functional roles of hADA3 to provoke further interest for more elegant and intensive studies exploring assorted aspects of this protein. PMID:27605378

  17. Co-Activation of Epidermal Growth Factor Receptor and c-MET Defines a Distinct Subset of Lung Adenocarcinomas

    PubMed Central

    Matsubara, Daisuke; Ishikawa, Shumpei; Sachiko, Oguni; Aburatani, Hiroyuki; Fukayama, Masashi; Niki, Toshiro

    2010-01-01

    Epidermal growth factor receptor (EGFR) and MET are molecular targets for lung cancer treatment. The relationships between expression, activation, and gene abnormalities of these two targets are currently unclear. Here, we demonstrate that a panel of 40 lung cancer cell lines could be classified into two groups. Group I was characterized by (1) high phosphorylations of MET and EGFR, (2) frequent mutation or amplification of EGFR, MET, and human epidermal growth factor receptor-2 (HER2), (3) high expressions of bronchial epithelial markers (thyroid transcription factor-1 (TTF-1), MUC1, and Cytokeratin 7 (CK7)); and (4) high expressions of MET, human epidermal growth factor receptor-3, E-cadherin, cyclooxygenase-2, and laminin gamma2. In contrast, Group II exhibited little or no phosphorylation of MET and EGFR; no mutation or amplification of EGFR, MET, and HER2; were triple-negative for TTF-1, MUC1, and CK7; and showed high expressions of vimentin, fibroblast growth factor receptor-1, and transcription factor 8. Importantly, Group I was more sensitive to gefitinib and more resistant to cisplatin and paclitaxel than Group II. The clinical relevance was confirmed in publicly available data on 442 primary lung adenocarcinoma patients; survival benefits by postoperative chemotherapy were seen in only patients with tumors corresponding to Group II. Overall, co-activation of EGFR and MET defines a distinct subgroup of lung carcinoma with characteristic genetic abnormalities, gene expression pattern, and response to chemotherapeutic reagents. PMID:20934974

  18. Simulated microgravity inhibits osteogenic differentiation of mesenchymal stem cells through down regulating the transcriptional co-activator TAZ.

    PubMed

    Chen, Zhe; Luo, Qing; Lin, Chuanchuan; Song, Guanbin

    Microgravity induces observed bone loss in space flight or simulated experiments, while the mechanism underlying it is still obscure. Here, we utilized a clinostat to model simulated microgravity (SMG) and found that SMG obviously inhibited osteogenic differentiation of rat bone marrow mesenchymal stem cells (BMSCs). We detected that SMG dramatically inhibited the expression of the transcriptional coactivator with PDZ-binding motif (TAZ), which acts as a vital regulator of osteogenesis. Interestingly, we found that lysophosphatidic acid (LPA) could activate TAZ and retain osteogenic differentiation of BMSCs under SMG. Our data further demonstrated that depletion of TAZ by siRNA blocked the LPA-induced increase in osteogenic differentiation of BMSCs under SMG. Moreover, Y27632 (the Rock inhibitor) abrogated the activation of TAZ and the increased osteogenic differentiation induced by LPA. Taken together, we propose that microgravity inhibits osteogenic differentiation of BMSCs due to decreased TAZ expression and that LPA can efficiently reverse the reduced osteogenic differentiation via the Rock-TAZ pathway. PMID:26549225

  19. Rho-actin signaling to the MRTF coactivators dominates the immediate transcriptional response to serum in fibroblasts

    PubMed Central

    Esnault, Cyril; Stewart, Aengus; Gualdrini, Francesco; East, Phil; Horswell, Stuart; Matthews, Nik; Treisman, Richard

    2014-01-01

    The transcription factor SRF (serum response factor) recruits two families of coactivators, the MRTFs (myocardin-related transcription factors) and the TCFs (ternary complex factors), to couple gene transcription to growth factor signaling. Here we investigated the role of the SRF network in the immediate transcriptional response of fibroblasts to serum stimulation. SRF recruited its cofactors in a gene-specific manner, and virtually all MRTF binding was directed by SRF. Much of SRF DNA binding was serum-inducible, reflecting a requirement for MRTF–SRF complex formation in nucleosome displacement. We identified 960 serum-responsive SRF target genes, which were mostly MRTF-controlled, as assessed by MRTF chromatin immunoprecipitation (ChIP) combined with deep sequencing (ChIP-seq) and/or sensitivity to MRTF-linked signals. MRTF activation facilitates RNA polymerase II (Pol II) recruitment or promoter escape according to gene context. MRTF targets encode regulators of the cytoskeleton, transcription, and cell growth, underpinning the role of SRF in cytoskeletal dynamics and mechanosensing. Finally, we show that specific activation of either MRTFs or TCFs can reset the circadian clock. PMID:24732378

  20. Grainyhead-like 2 inhibits the coactivator p300, suppressing tubulogenesis and the epithelial-mesenchymal transition.

    PubMed

    Pifer, Phillip M; Farris, Joshua C; Thomas, Alyssa L; Stoilov, Peter; Denvir, James; Smith, David M; Frisch, Steven M

    2016-08-01

    Developmental morphogenesis and tumor progression require a transient or stable breakdown of epithelial junctional complexes to permit programmed migration, invasion, and anoikis resistance, characteristics endowed by the epithelial-mesenchymal transition (EMT). The epithelial master-regulatory transcription factor Grainyhead-like 2 (GRHL2) suppresses and reverses EMT, causing a mesenchymal-epithelial transition to the default epithelial phenotype. Here we investigated the role of GRHL2 in tubulogenesis of Madin-Darby canine kidney cells, a process requiring transient, partial EMT. GRHL2 was required for cystogenesis, but it suppressed tubulogenesis in response to hepatocyte growth factor. Surprisingly, GRHL2 suppressed this process by inhibiting the histone acetyltransferase coactivator p300, preventing the induction of matrix metalloproteases and other p300-dependent genes required for tubulogenesis. A 13-amino acid region of GRHL2 was necessary for inhibition of p300, suppression of tubulogenesis, and interference with EMT. The results demonstrate that p300 is required for partial or complete EMT occurring in tubulogenesis or tumor progression and that GRHL2 suppresses EMT in both contexts through inhibition of p300. PMID:27251061

  1. Peroxisome Proliferator-activated Receptor-γ Coactivator 1-α (PGC1α) Protects against Experimental Murine Colitis.

    PubMed

    Cunningham, Kellie E; Vincent, Garret; Sodhi, Chhinder P; Novak, Elizabeth A; Ranganathan, Sarangarajan; Egan, Charlotte E; Stolz, Donna Beer; Rogers, Matthew B; Firek, Brian; Morowitz, Michael J; Gittes, George K; Zuckerbraun, Brian S; Hackam, David J; Mollen, Kevin P

    2016-05-01

    Peroxisome proliferator-activated receptor-γ coactivator 1-α (PGC1α) is the primary regulator of mitochondrial biogenesis and was recently found to be highly expressed within the intestinal epithelium. PGC1α is decreased in the intestinal epithelium of patients with inflammatory bowel disease, but its role in pathogenesis is uncertain. We now hypothesize that PGC1α protects against the development of colitis and helps to maintain the integrity of the intestinal barrier. We selectively deleted PGC1α from the intestinal epithelium of mice by breeding a PGC1α(loxP/loxP) mouse with a villin-cre mouse. Their progeny (PGC1α(ΔIEC) mice) were subjected to 2% dextran sodium sulfate (DSS) colitis for 7 days. The SIRT1 agonist SRT1720 was used to enhance PGC1α activation in wild-type mice during DSS exposure. Mice lacking PGC1α within the intestinal epithelium were more susceptible to DSS colitis than their wild-type littermates. Pharmacologic activation of PGC1α successfully ameliorated disease and restored mitochondrial integrity. These findings suggest that a depletion of PGC1α in the intestinal epithelium contributes to inflammatory changes through a failure of mitochondrial structure and function as well as a breakdown of the intestinal barrier, which leads to increased bacterial translocation. PGC1α induction helps to maintain mitochondrial integrity, enhance intestinal barrier function, and decrease inflammation. PMID:26969166

  2. Essential Phosphatases and a Phospho-Degron Are Critical for Regulation of SRC-3/AIB1 Coactivator Function and Turnover

    PubMed Central

    Li, Chao; Liang, Yao-Yun; Feng, Xin-Hua; Tsai, Sophia Y.; Tsai, Ming-Jer; O’Malley, Bert W.

    2008-01-01

    SRC-3/AIB1 is a master growth coactivator and oncogene, and phosphorylation activates it into a powerful coregulator. Dephosphorylation is a potential regulatory mechanism for SRC-3 function but the identity of such phosphatases remains unexplored. Herein, we report that using functional genomic screening of human Ser/Thr phosphatases targeting SRC-3’s known phosphorylation sites, the phosphatases PDXP, PP1 and PP2A were identified to be key negative regulators of SRC-3 transcriptional coregulatory activity in steroid receptor signalings. PDXP and PP2A dephosphorylate SRC-3 and inhibit its ligand-dependent association with estrogen receptor. PP1 stabilizes SRC-3 protein by blocking its proteasome-dependent turnover through dephosphorylation of two previously unidentified phosphorylation sites (Ser101 and S102) required for activity. These two sites are located within a degron of SRC-3, and are primary determinants of SRC-3 turnover. Moreover, PP1 regulates the oncogenic cell proliferation and invasion functions of SRC-3 in breast cancer cells. PMID:18922467

  3. Functional and mechanistic studies of XPC DNA-repair complex as transcriptional coactivator in embryonic stem cells

    PubMed Central

    Cattoglio, Claudia; Zhang, Elisa T.; Grubisic, Ivan; Chiba, Kunitoshi; Fong, Yick W.; Tjian, Robert

    2015-01-01

    The embryonic stem cell (ESC) state is transcriptionally controlled by OCT4, SOX2, and NANOG with cofactors, chromatin regulators, noncoding RNAs, and other effectors of signaling pathways. Uncovering components of these regulatory circuits and their interplay provides the knowledge base to deploy ESCs and induced pluripotent stem cells. We recently identified the DNA-repair complex xeroderma pigmentosum C (XPC)-RAD23B-CETN2 as a stem cell coactivator (SCC) required for OCT4/SOX2 transcriptional activation. Here we investigate the role of SCC genome-wide in murine ESCs by mapping regions bound by RAD23B and analyzing transcriptional profiles of SCC-depleted ESCs. We establish OCT4 and SOX2 as the primary transcription factors recruiting SCC to regulatory regions of pluripotency genes and identify the XPC subunit as essential for interaction with the two proteins. The present study reveals new mechanistic and functional aspects of SCC transcriptional activity, and thus underscores the diversified functions of this regulatory complex. PMID:25901318

  4. Substratum-induced differentiation of human pluripotent stem cells reveals the coactivator YAP is a potent regulator of neuronal specification

    PubMed Central

    Musah, Samira; Wrighton, Paul J.; Zaltsman, Yefim; Zhong, Xiaofen; Zorn, Stefan; Parlato, Matthew B.; Hsiao, Cheston; Palecek, Sean P.; Chang, Qiang; Murphy, William L.; Kiessling, Laura L.

    2014-01-01

    Physical stimuli can act in either a synergistic or antagonistic manner to regulate cell fate decisions, but it is less clear whether insoluble signals alone can direct human pluripotent stem (hPS) cell differentiation into specialized cell types. We previously reported that stiff materials promote nuclear localization of the Yes-associated protein (YAP) transcriptional coactivator and support long-term self-renewal of hPS cells. Here, we show that even in the presence of soluble pluripotency factors, compliant substrata inhibit the nuclear localization of YAP and promote highly efficient differentiation of hPS cells into postmitotic neurons. In the absence of neurogenic factors, the effective substrata produce neurons rapidly (2 wk) and more efficiently (>75%) than conventional differentiation methods. The neurons derived from substrate induction express mature markers and possess action potentials. The hPS differentiation observed on compliant surfaces could be recapitulated on stiff surfaces by adding small-molecule inhibitors of F-actin polymerization or by depleting YAP. These studies reveal that the matrix alone can mediate differentiation of hPS cells into a mature cell type, independent of soluble inductive factors. That mechanical cues can override soluble signals suggests that their contributions to early tissue development and lineage commitment are profound. PMID:25201954

  5. Outcome-dependent coactivation of lip and tongue primary somatosensory representation following hypoglossal-facial transfer after peripheral facial palsy.

    PubMed

    Rottler, Philipp; Schroeder, Henry W S; Lotze, Martin

    2014-02-01

    A hypoglossal-facial transfer is a common surgical strategy for reanimating the face after persistent total hemifacial palsy. We were interested in how motor recovery is associated with cortical reorganization of lip and tongue representation in the primary sensorimotor cortex after the transfer. Therefore, we used functional magnetic resonance imaging (fMRI) in 13 patients who underwent a hypoglossal-facial transfer after unilateral peripheral facial palsy. To identify primary motor and somatosensory tongue and lip representation sites, we measured repetitive tongue and lip movements during fMRI. Electromyography (EMG) of the perioral muscles during tongue and lip movements and standardized evaluation of lip elevation served as outcome parameters. We found an association of cortical representation sites in the pre- and postcentral gyrus (decreased distance of lip and tongue representation) with symmetry of recovered lip movements (lip elevation) and coactivation of the lip during voluntary tongue movements (EMG-activity of the lip during tongue movements). Overall, our study shows that hypoglossal-facial transfer resulted in an outcome-dependent cortical reorganization with activation of the cortical tongue area for restituded movement of the lip. PMID:23124599

  6. Process of up-conversion in glass ceramics, coactivated by thulium and ytterbium

    SciTech Connect

    de Sa, G.F.; Malta, O.L.; Santa Cruz, P.A.; Portela, C.F.

    1988-03-01

    The authors studied the blue emission (approx. 480 nm) from the /sup 1/G/sub 4/ level of Tm/sup 3 +/, in a vitroceramic material doped with Yb/sup 3 +/ ions, as a function of Yb/sup 3 +/ concentration. First they have studied the /sup 1/G/sub 4/ ..-->.. /sup 3/H/sub 6/ blue emission from Tm/sup 3 +/ through infrared excitation of the /sup 5/F/sub 5///sub 2/ level of Yb/sup 3 +/. The intensity of this emission shows a maximum at a Yb/sup 3 +/ concentration around 7.5%. Then, motivated by this results, they measured the resonant fluorescence by exciting the /sup 1/G/sub 4/ level with an argon laser at approx. 472 nm. The fluorescence intensity shows a decreasing behavior with increasing Yb/sup 3 +/ concentration. These results suggest that the /sup 1/G/sub 4/ level is being quenched by the Yb/sup 3 +/ ions. Assuming that diffusion between Yb/sup 3 +/ ions is sufficiently rapid, they apply the rate-equation model to rationalize these experimental results. They conclude that the simultaneous double back-transfer rate (cooperative back-transfer) plays the crucial role in the observed quenching process of the /sup 1/G/sub 4/ level.

  7. Guided Play: Where Curricular Goals Meet a Playful Pedagogy

    ERIC Educational Resources Information Center

    Weisberg, Deena Skolnick; Hirsh-Pasek, Kathy; Golinkoff, Roberta Michnick

    2013-01-01

    Decades of research demonstrate that a strong curricular approach to preschool education is important for later developmental outcomes. Although these findings have often been used to support the implementation of educational programs based on direct instruction, we argue that "guided play" approaches can be equally effective at delivering content…

  8. Parent-Child Play across Cultures: Advancing Play Research

    ERIC Educational Resources Information Center

    Roopnarine, Jaipaul L.; Davidson, Kimberly L.

    2015-01-01

    In this article, the authors argue for a greater understanding of children's play across cultures through better integration of scientific thinking about the developed and developing societies, through consideration of socialization beliefs and goals, and, finally, through the use of more complex models in research investigations. They draw on…

  9. Winnetka deformation zone: Surface expression of coactive slip on a blind fault during the Northridge earthquake sequence, California. Evidence that coactive faulting occurred in the Canoga Park, Winnetka, and Northridge areas during the 17 January 1994, Northridge, California earthquake

    SciTech Connect

    Cruikshank, K.M.; Johnson, A.M.; Fleming, R.W.; Jones, R.L.

    1996-12-31

    observations that a large earthquake sequence can include rupture along both a main fault and nearby faults with quite different senses of slip. Faults near the main fault that approach the ground surface or cut the surface in an area have the potential of moving coactively in a major earthquake. Movement on such faults is associated with significant damage during an earthquake. The fault that produced the main Northridge shock and the faults that moved coactively in the Northridge area probably are parts of a large structure. Such interrelationships may be key to understanding earthquakes and damage caused by tectonism.

  10. Play Chinese Games. 1987, Revised.

    ERIC Educational Resources Information Center

    White, Caryn

    This document, designed to introduce all ages to a selection of popular Chinese games, describes these games and provides instructions and materials for making the items needed to play most of them. Section 1 suggests class activities that can be related to some of the games. Section 2 presents instructions for the physical or outdoor games of:…

  11. Moral Education through Play Therapy

    ERIC Educational Resources Information Center

    Mahalle, Salwa; Zakaria, Gamal Abdul Nasir; Nawi, Aliff

    2014-01-01

    This paper will discuss on how sand therapy (as one type of play therapies) can be applied as an additional technique or approach in counseling. The research questions for this study are to see what are the development, challenges faced by the therapist during the sessions given and how sand therapy can aid to the progress of the client. It is a…

  12. In Search of Serious Play

    ERIC Educational Resources Information Center

    Wallace, David

    2005-01-01

    All teaching artists have taken unexpected detours that lead to miracles. They have all created magical experiences in which people are too engaged to notice the incredible amount they are learning. As a TA, one searches for "serious play"--purposeful fun that stimulates exhilarating work and genuine learning. But how does it happen? How do TAs…

  13. Sculpting Cells with Play Doh.

    ERIC Educational Resources Information Center

    Way, Virginia A.

    1982-01-01

    Suggests using Play Doh to mold models of the nucleus, mitochondria, and inner cellular structures. Students can conceptualize the cell's structures as three-dimensional even though they appear two-dimensional under a microscope. Includes instructions for preparing homemade dough. (Author/JN)

  14. Children's Voices through Dramatic Play.

    ERIC Educational Resources Information Center

    Sierra, Zayda

    Dramatic play provides children an excellent way to express their feelings and perceptions of the world that surrounds them. It is also an alternative way for researchers and teachers to capture, understand, and interpret children's voices because of the difficulties that children have in expressing ideas through oral and written language. While…

  15. Building Curriculum during Block Play

    ERIC Educational Resources Information Center

    Andrews, Nicole

    2015-01-01

    Blocks are not just for play! In this article, Nicole Andrews describes observing the interactions of three young boys enthusiastically engaged in the kindergarten block center of their classroom, using blocks in a building project that displayed their ability to use critical thinking skills, physics exploration, and the development of language…

  16. Interpretive Reproduction in Children's Play

    ERIC Educational Resources Information Center

    Corsaro, William A.

    2012-01-01

    The author looks at children's play from the perspective of interpretive reproduction, emphasizing the way children create their own unique peer cultures, which he defines as a set of routines, artifacts, values, and concerns that children engage in with their playmates. The article focuses on two types of routines in the peer culture of preschool…

  17. Fort Play Children Recreate Recess

    ERIC Educational Resources Information Center

    Powell, Mark

    2007-01-01

    Recess beckons well before it actually arrives. Its allure can be heard in children's lunchtime conversations as they discuss imaginary roles, plans, alliances and teams, with an obvious appetite for play and its unbounded possibility. For some children, recess provides the most important reasons to come to school. In team sports, games of chase…

  18. Obama Plays Cheerleader for STEM

    ERIC Educational Resources Information Center

    Robelen, Erik W.

    2010-01-01

    Amid a struggling economy, a raft of foreign-policy headaches, and the tail end of a heated campaign season, President Barack Obama carved out time in his schedule last month to watch students in the State Dining Room demonstrate a solar-powered model car, a water-purification system, and a soccer-playing robot. The science fair was the fifth…

  19. Science Adventures in Children's Play.

    ERIC Educational Resources Information Center

    Rieger, Edythe

    The stated purpose of this pamphlet is to suggest simple, natural, interesting experiences in children's play that have science implications. It tells how the teacher may capitalize on the innate curiosity of children by incorporating science discovery in daily classroom experiences. This how-to-do-it manual directs map-making and activities for…

  20. Play Therapy with the Nonverbal.

    ERIC Educational Resources Information Center

    Leland, Henry

    Four developmental outcomes of children's play were identified as acquaintance with the environment and the development of cognitive activity, verification of incidental learning, the development through sensory and motoric activities of relationships with objects and persons, and experience with roles and rules. A child developing atypically may…

  1. Building Math through Play Everyday

    ERIC Educational Resources Information Center

    Clements, Douglas H.; Sarama, Julie

    2005-01-01

    This article focuses on how young children build math skills in everyday play and activities. Children focus on six categories of mathematical content including classifying, exploring magnitude, enumerating, investigating dynamics, studying patterns, and exploring spatial relations. The article gives advice to both teachers and parents on how they…

  2. Creating Outdoor Play & Learning Environments.

    ERIC Educational Resources Information Center

    White, Randy; Stoecklin, Vicki L.

    Why typical playgrounds are designed the way they are by adults is discussed, including what the ideal outdoor play/learning environment for children is and how the outdoor space should be considered as an extension of the classroom. The paper emphasizes the importance of nature to children, discusses the criteria playground designers should…

  3. Playing It Safe: Part II.

    ERIC Educational Resources Information Center

    Penman, Kenneth A.; Niccolai, Frances R.

    1985-01-01

    Explains how to prevent outdoor sports injuries; discusses related litigation and specific cases involving playing field turf, tennis, skiing, and pools; and sets out facility design and maintenance considerations and recommendations. A sidebar provides information about injury insurance available to NCAA schools. Part I of this article appeared…

  4. Child-Centered Play Therapy

    ERIC Educational Resources Information Center

    VanFleet, Rise; Sywulak, Andrea E.; Sniscak, Cynthia Caparosa

    2010-01-01

    Highly practical, instructive, and authoritative, this book vividly describes how to conduct child-centered play therapy. The authors are master clinicians who explain core therapeutic principles and techniques, using rich case material to illustrate treatment of a wide range of difficulties. The focus is on nondirective interventions that allow…

  5. Playing Piano across the Curriculum.

    ERIC Educational Resources Information Center

    Hamel, Barbara L.

    2000-01-01

    Contends that the amount of piano study required of music education majors to pass the piano proficiency examination is insufficient. States that keyboarding across the curriculum will enable music education majors to become proficient in playing the piano. Offers suggestions for including the keyboard within other courses. (CMK)

  6. Caloric Cost of Playing Golf

    ERIC Educational Resources Information Center

    Lampley, James H.; And Others

    1977-01-01

    Women who play golf at the same rate of speed as men will use energy at a higher rate, but the rapidity with which the course is completed, which is dependent on the number of members of the golfing party, is a factor in the caloric expenditure of both sexes. (JD)

  7. Integrating Time, Place, and Play

    ERIC Educational Resources Information Center

    Gallavan, Nancy P.

    2004-01-01

    "Time, Place, and Play," is a short phrase, but is summarizes three very big concepts--history, geography, and culture--that are part of the elementary social studies curriculum. This article relates the story of how twenty-five elementary and middle school teachers, meeting over several weeks in a university class, designed a unit of study on the…

  8. Transcriptional Coactivator Cited2 Induces Bmi1 and Mel18 and Controls Fibroblast Proliferation via Ink4a/ARF

    PubMed Central

    Kranc, Kamil R.; Bamforth, Simon D.; Bragança, José; Norbury, Chris; van Lohuizen, Maarten; Bhattacharya, Shoumo

    2003-01-01

    Cited2 (CBP/p300 interacting transactivator with ED-rich tail 2) is required for embryonic development, coactivation of transcription factor AP-2, and inhibition of hypoxia-inducible factor 1 transactivation. Cited2 is induced by multiple growth factors and cytokines and oncogenically transforms cells. Here, we show that the proliferation of Cited2−/− mouse embryonic fibroblasts ceases prematurely. This is associated with a reduction in growth fraction, senescent cellular morphology, and increased expression of the cell proliferation inhibitors p16INK4a, p19ARF, and p15INK4b. Deletion of INK4a/ARF (encoding p16INK4a and p19ARF) completely rescued the defective proliferation of Cited2−/− fibroblasts. However, the deletion of INK4a/ARF did not rescue the embryonic malformations observed in Cited2−/− mice, indicating that INK4a/ARF-independent pathways are likely to be involved here. We found that Cited2−/− fibroblasts had reduced expression of the polycomb-group genes Bmi1 and Mel18, which function as INK4a/ARF and Hox repressors. Complementation with CITED2-expressing retrovirus enhanced proliferation, induced Bmi1/Mel18 expression, and decreased INK4a/ARF expression. Bmi1- and Mel18-expressing retroviruses enhanced the proliferation of Cited2−/− fibroblasts, indicating that they function downstream of Cited2. Our results provide genetic evidence that Cited2 controls the expression of INK4a/ARF and fibroblast proliferation, at least in part via the polycomb-group genes Bmi1 and Mel18. PMID:14560011

  9. Filamin A interacts with the coactivator MKL1 to promote the activity of the transcription factor SRF and cell migration.

    PubMed

    Kircher, Philipp; Hermanns, Constanze; Nossek, Maximilian; Drexler, Maria Katharina; Grosse, Robert; Fischer, Maximilian; Sarikas, Antonio; Penkava, Josef; Lewis, Thera; Prywes, Ron; Gudermann, Thomas; Muehlich, Susanne

    2015-11-10

    Megakaryoblastic leukemia 1 (MKL1) is a coactivator of serum response factor (SRF) that promotes the expression of genes associated with cell proliferation, motility, adhesion, and differentiation-processes that also involve dynamic cytoskeletal changes in the cell. MKL1 is inactive when bound to monomeric globular actin (G-actin), but signals that activate the small guanosine triphosphatase RhoA cause actin polymerization and MKL1 dissociation from G-actin. We found a new mechanism of MKL1 activation that is mediated through its binding to filamin A (FLNA), a protein that binds filamentous actin (F-actin). The interaction of FLNA and MKL1 was required for the expression of MKL1 target genes in primary fibroblasts, melanoma, mammary and hepatocellular carcinoma cells. We identified the regions of interaction between MKL1 and FLNA, and cells expressing an MKL1 mutant that was unable to bind FLNA exhibited impaired cell migration and reduced expression of MKL1-SRF target genes. Induction and repression of MKL1-SRF target genes correlated with increased or decreased MKL1-FLNA interaction, respectively. Lysophosphatidic acid-induced RhoA activation in primary human fibroblasts promoted the association of endogenous MKL1 with FLNA, whereas exposure to an actin polymerization inhibitor dissociated MKL1 from FLNA and decreased MKL1-SRF target gene expression in melanoma cells. Thus, FLNA functions as a positive cellular transducer linking actin polymerization to MKL1-SRF activity, counteracting the known repressive complex of MKL1 and monomeric G-actin. PMID:26554816

  10. Enforced Expression of the Transcriptional Coactivator OBF1 Impairs B Cell Differentiation at the Earliest Stage of Development

    PubMed Central

    Du Roure, Camille; Bartholdy, Boris; Kohler, Hubertus; Matthias, Gabriele; Rolink, Antonius G.; Matthias, Patrick

    2008-01-01

    OBF1, also known as Bob.1 or OCA-B, is a B lymphocyte-specific transcription factor which coactivates Oct1 and Oct2 on B cell specific promoters. So far, the function of OBF1 has been mainly identified in late stage B cell populations. The central defect of OBF1 deficient mice is a severely reduced immune response to T cell-dependent antigens and a lack of germinal center formation in the spleen. Relatively little is known about a potential function of OBF1 in developing B cells. Here we have generated transgenic mice overexpressing OBF1 in B cells under the control of the immunoglobulin heavy chain promoter and enhancer. Surprisingly, these mice have greatly reduced numbers of follicular B cells in the periphery and have a compromised immune response. Furthermore, B cell differentiation is impaired at an early stage in the bone marrow: a first block is observed during B cell commitment and a second differentiation block is seen at the large preB2 cell stage. The cells that succeed to escape the block and to differentiate into mature B cells have post-translationally downregulated the expression of transgene, indicating that expression of OBF1 beyond the normal level early in B cell development is deleterious. Transcriptome analysis identified genes deregulated in these mice and Id2 and Id3, two known negative regulators of B cell differentiation, were found to be upregulated in the EPLM and preB cells of the transgenic mice. Furthermore, the Id2 and Id3 promoters contain octamer-like sites, to which OBF1 can bind. These results provide evidence that tight regulation of OBF1 expression in early B cells is essential to allow efficient B lymphocyte differentiation. PMID:19104664

  11. Targeting of p300/CREB binding protein coactivators by simian virus 40 is mediated through p53.

    PubMed

    Borger, Darrell R; DeCaprio, James A

    2006-05-01

    The primary transforming functions of simian virus 40 large T antigen (SV40 LT) are conferred primarily through the binding and inactivation of p53 and the retinoblastoma family members. Normal p53 function requires an association with the CREB binding protein (CBP)/p300 coactivators, and a ternary complex containing SV40 LT, p53, and CBP/p300 has been identified previously. In this report, we have evaluated a secondary function of p53 bound to the SV40 LT complex in mediating the binding of human CBP/p300. We demonstrate that p53 associated with SV40 LT was posttranslationally modified in a manner consistent with the binding of CBP/p300. Furthermore, expression of SV40 LT induced the proportion of p53 phosphorylated on S15. An essential function for p53 in bridging the interaction between SV40 LT and CBP/p300 was identified through the reconstitution of the SV40 LT-CBP/p300 complex upon p53 reexpression in p53-null cells. In addition, the SV40 LT-CBP/p300 complex was disrupted through RNA interference-mediated depletion of endogenous p53. We also demonstrate that SV40 LT was acetylated in a p300- and p53-dependent manner, at least in part through the CH3 domain of p300. Therefore, the binding of p53 serves to modify SV40 LT by targeting CBP and p300 binding to direct the acetylation of SV40 LT. PMID:16611888

  12. Targeting of p300/CREB Binding Protein Coactivators by Simian Virus 40 Is Mediated through p53

    PubMed Central

    Borger, Darrell R.; DeCaprio, James A.

    2006-01-01

    The primary transforming functions of simian virus 40 large T antigen (SV40 LT) are conferred primarily through the binding and inactivation of p53 and the retinoblastoma family members. Normal p53 function requires an association with the CREB binding protein (CBP)/p300 coactivators, and a ternary complex containing SV40 LT, p53, and CBP/p300 has been identified previously. In this report, we have evaluated a secondary function of p53 bound to the SV40 LT complex in mediating the binding of human CBP/p300. We demonstrate that p53 associated with SV40 LT was posttranslationally modified in a manner consistent with the binding of CBP/p300. Furthermore, expression of SV40 LT induced the proportion of p53 phosphorylated on S15. An essential function for p53 in bridging the interaction between SV40 LT and CBP/p300 was identified through the reconstitution of the SV40 LT-CBP/p300 complex upon p53 reexpression in p53-null cells. In addition, the SV40 LT-CBP/p300 complex was disrupted through RNA interference-mediated depletion of endogenous p53. We also demonstrate that SV40 LT was acetylated in a p300- and p53-dependent manner, at least in part through the CH3 domain of p300. Therefore, the binding of p53 serves to modify SV40 LT by targeting CBP and p300 binding to direct the acetylation of SV40 LT. PMID:16611888

  13. Estrogen target gene regulation and coactivator expression in rat uterus after developmental exposure to the ultraviolet filter 4-methylbenzylidene camphor.

    PubMed

    Durrer, Stefan; Maerkel, Kirsten; Schlumpf, Margret; Lichtensteiger, Walter

    2005-05-01

    Because the estrogen receptor (ER) ligand type influences transactivation, it is important to obtain information on molecular actions of nonclassical ER agonists. UV filters from cosmetics represent new classes of endocrine active chemicals, including the preferential ER beta ligands 4-methylbenzylidene camphor (4-MBC) and 3-benzylidene camphor. We studied estrogen target gene expression in uterus of Long Evans rats after developmental exposure to 4-MBC (0.7, 7, 24, and 47 mg/kg x d) administered in feed to the parent generation before mating, during pregnancy and lactation, and to the offspring until adulthood. 4-MBC altered steady-state levels of mRNAs encoding for ER alpha, ER beta, progesterone receptor (PR), IGF-I, androgen receptor, determined by real-time RT-PCR in uterus of 12-wk-old offspring. Western-blot analyses of the same tissue homogenates indicated changes in ER alpha and PR but not ER beta proteins. To assess sensitivity to estradiol (E2), offspring were ovariectomized on d 70, injected with E2 (10 or 50 microg/kg sc) on d 84, and killed 6 h later. Acute up-regulation of PR and IGF-I and down-regulation of ER alpha and androgen receptor by E2 were dose-dependently reduced in 4-MBC-exposed rats. The reduced response to E2 was accompanied by reduced coactivator SRC-1 mRNA and protein levels. Our data indicate that developmental exposure to 4-MBC affects the regulation of estrogen target genes and the expression of nuclear receptor coregulators in uterus at mRNA and protein levels. PMID:15705771

  14. SPBP Is a Sulforaphane Induced Transcriptional Coactivator of NRF2 Regulating Expression of the Autophagy Receptor p62/SQSTM1

    PubMed Central

    Darvekar, Sagar Ramesh; Elvenes, Julianne; Brenne, Hanne Britt; Johansen, Terje; Sjøttem, Eva

    2014-01-01

    Organisms exposed to oxidative stress respond by orchestrating a stress response to prevent further damage. Intracellular levels of antioxidant agents increase, and damaged components are removed by autophagy induction. The KEAP1-NRF2 signaling pathway is the main pathway responsible for cell defense against oxidative stress and for maintaining the cellular redox balance at physiological levels. Sulforaphane, an isothiocyanate derived from cruciferous vegetables, is a potent inducer of KEAP1-NRF2 signaling and antioxidant response element driven gene expression. In this study, we show that sulforaphane enhances the expression of the transcriptional coregulator SPBP. The expression curve peaks 6–8 hours post stimulation, and parallels the sulforaphane-induced expression of NRF2 and the autophagy receptor protein p62/SQSTM1. Reporter gene assays show that SPBP stimulates the expression of p62/SQSTM1 via ARE elements in the promoter region, and siRNA mediated knock down of SPBP significantly decreases the expression of p62/SQSTM1 and the formation of p62/SQSTM1 bodies in HeLa cells. Furthermore, SPBP siRNA reduces the sulforaphane induced expression of NRF2, and the expression of the autophagy marker protein LC3B. Both these proteins contain ARE-like elements in their promoter regions. Over-expressed SPBP and NRF2 acts synergistically on the p62/SQSTM1 promoter and colocalize in nuclear speckles in HeLa cells. Collectively, these results suggest that SPBP is a coactivator of NRF2, and hence may be important for securing enhanced and sustained expression of NRF2 induced genes such as proteins involved in selective autophagy. PMID:24416372

  15. SPBP is a sulforaphane induced transcriptional coactivator of NRF2 regulating expression of the autophagy receptor p62/SQSTM1.

    PubMed

    Darvekar, Sagar Ramesh; Elvenes, Julianne; Brenne, Hanne Britt; Johansen, Terje; Sjøttem, Eva

    2014-01-01

    Organisms exposed to oxidative stress respond by orchestrating a stress response to prevent further damage. Intracellular levels of antioxidant agents increase, and damaged components are removed by autophagy induction. The KEAP1-NRF2 signaling pathway is the main pathway responsible for cell defense against oxidative stress and for maintaining the cellular redox balance at physiological levels. Sulforaphane, an isothiocyanate derived from cruciferous vegetables, is a potent inducer of KEAP1-NRF2 signaling and antioxidant response element driven gene expression. In this study, we show that sulforaphane enhances the expression of the transcriptional coregulator SPBP. The expression curve peaks 6-8 hours post stimulation, and parallels the sulforaphane-induced expression of NRF2 and the autophagy receptor protein p62/SQSTM1. Reporter gene assays show that SPBP stimulates the expression of p62/SQSTM1 via ARE elements in the promoter region, and siRNA mediated knock down of SPBP significantly decreases the expression of p62/SQSTM1 and the formation of p62/SQSTM1 bodies in HeLa cells. Furthermore, SPBP siRNA reduces the sulforaphane induced expression of NRF2, and the expression of the autophagy marker protein LC3B. Both these proteins contain ARE-like elements in their promoter regions. Over-expressed SPBP and NRF2 acts synergistically on the p62/SQSTM1 promoter and colocalize in nuclear speckles in HeLa cells. Collectively, these results suggest that SPBP is a coactivator of NRF2, and hence may be important for securing enhanced and sustained expression of NRF2 induced genes such as proteins involved in selective autophagy. PMID:24416372

  16. Coactivator MYST1 regulates nuclear factor-κB and androgen receptor functions during proliferation of prostate cancer cells.

    PubMed

    Jaganathan, Anbalagan; Chaurasia, Pratima; Xiao, Guang-Qian; Philizaire, Marc; Lv, Xiang; Yao, Shen; Burnstein, Kerry L; Liu, De-Pei; Levine, Alice C; Mujtaba, Shiraz

    2014-06-01

    In prostate cancer (PCa), the functional synergy between androgen receptor (AR) and nuclear factor-κ B (NF-κB) escalates the resistance to therapeutic regimens and promotes aggressive tumor growth. Although the underlying mechanisms are less clear, gene regulatory abilities of coactivators can bridge the transcription functions of AR and NF-κB. The present study shows that MYST1 (MOZ, YBF2 and SAS2, and TIP60 protein 1) costimulates AR and NF-κB functions in PCa cells. We demonstrate that activation of NF-κB promotes deacetylation of MYST1 by sirtuin 1. Further, the mutually exclusive interactions of MYST1 with sirtuin 1 vs AR regulate the acetylation of lysine 16 on histone H4. Notably, in AR-lacking PC3 cells and in AR-depleted LNCaP cells, diminution of MYST1 activates the cleavage of poly(ADP-ribose) polymerase and caspase 3 that leads to apoptosis. In contrast, in AR-transformed PC3 cells (PC3-AR), depletion of MYST1 induces cyclin-dependent kinase (CDK) N1A/p21, which results in G2M arrest. Concomitantly, the levels of phospho-retinoblastoma, E2F1, CDK4, and CDK6 are reduced. Finally, the expression of tumor protein D52 (TPD52) was unequivocally affected in PC3, PC3-AR, and LNCaP cells. Taken together, the results of this study reveal that the functional interactions of MYST1 with AR and NF-κB are critical for PCa progression. PMID:24702180

  17. On the Origin of Muscle Synergies: Invariant Balance in the Co-activation of Agonist and Antagonist Muscle Pairs

    PubMed Central

    Hirai, Hiroaki; Miyazaki, Fumio; Naritomi, Hiroaki; Koba, Keitaro; Oku, Takanori; Uno, Kanna; Uemura, Mitsunori; Nishi, Tomoki; Kageyama, Masayuki; Krebs, Hermano Igo

    2015-01-01

    Investigation of neural representation of movement planning has attracted the attention of neuroscientists, as it may reveal the sensorimotor transformation essential to motor control. The analysis of muscle synergies based on the activity of agonist–antagonist (AA) muscle pairs may provide insight into such transformations, especially for a reference frame in the muscle space. In this study, we examined the AA concept using the following explanatory variables: the AA ratio, which is related to the equilibrium-joint angle, and the AA sum, which is associated with joint stiffness. We formulated muscle synergies as a function of AA sums, positing that muscle synergies are composite units of mechanical impedance. The AA concept can be regarded as another form of the equilibrium-point (EP) hypothesis, and it can be extended to the concept of EP-based synergies. We introduce, here, a novel tool for analyzing the neurological and motor functions underlying human movements and review some initial insights from our results about the relationships between muscle synergies, endpoint stiffness, and virtual trajectories (time series of EP). Our results suggest that (1) muscle synergies reflect an invariant balance in the co-activation of AA muscle pairs; (2) each synergy represents the basis for the radial, tangential, and null movements of the virtual trajectory in the polar coordinates centered on the specific joint at the base of the body; and (3) the alteration of muscle synergies (for example, due to spasticity or rigidity following neurological injury) results in significant distortion of endpoint stiffness and concomitant virtual trajectories. These results indicate that muscle synergies (i.e., the balance of muscle mechanical impedance) are essential for motor control. PMID:26636079

  18. Carob pod insoluble fiber exerts anti-atherosclerotic effects in rabbits through sirtuin-1 and peroxisome proliferator-activated receptor-γ coactivator-1α.

    PubMed

    Valero-Muñoz, María; Martín-Fernández, Beatriz; Ballesteros, Sandra; Lahera, Vicente; de las Heras, Natalia

    2014-09-01

    The aim of this study was to evaluate the potential effects of an insoluble dietary fiber from carob pod (IFC) (1 g ⋅ kg(-1) ⋅ d(-1) in the diet) on alterations associated with atherosclerosis in rabbits with dyslipidemia. Male New Zealand rabbits (n = 30) were fed the following diets for 8 wk: 1) a control diet (SF412; Panlab) as a control group representing normal conditions; 2) a control supplemented with 0.5% cholesterol + 14% coconut oil (DL) (SF302; Panlab) for 8 wk as a dyslipidemic group; and 3) a control containing 0.5% cholesterol + 14% coconut oil plus IFC (1 g ⋅ kg(-1) ⋅ d(-1)) (DL+IFC) for 8 wk. IFC was administered in a pellet mixed with the DL diet. The DL-fed group developed mixed dyslipidemia and atherosclerotic lesions, which were associated with endothelial dysfunction, inflammation, and fibrosis. Furthermore, sirtuin-1 (SIRT1) and peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) protein expression in the aorta were reduced to 77% and 63% of the control group, respectively (P < 0.05), in these rabbits. Administration of IFC to DL-fed rabbits reduced the size of the aortic lesion significantly (DL, 15.2% and DL+IFC, 2.6%) and normalized acetylcholine-induced relaxation (maximal response: control, 89.3%; DL, 61.6%; DL+IFC, 87.1%; P < 0.05) and endothelial nitric oxide synthase expression (DL, 52% and DL+IFC, 104% of the control group). IFC administration to DL-fed rabbits also reduced cluster of differentiation 36 (DL, 148% and DL+IFC, 104% of the control group; P < 0.05), plasminogen activator inhibitor-1 (DL, 141% and DL+IFC, 107% of the control group), tumor necrosis factor-α (DL, 166% and DL+IFC, 120% of the control group), vascular cell adhesion molecule-1 (DL, 153% and DL+IFC, 110% of the control group), transforming growth factor-β (DL, 173% and DL+IFC, 99% of the control group), and collagen I (DL, 157% and DL+IFC, 112% of the control group) in the aorta. These effects were accompanied by an enhancement of

  19. Symbolic Play in Preschool and Primary Settings.

    ERIC Educational Resources Information Center

    Nourot, Patricia Moninghan; Van Hoorn, Judith L.

    1991-01-01

    A review of research on children's symbolic play discusses ways for teachers to (1) defend the inclusion of play in the curriculum; (2) understand and respect differences in the ways children play; and (3) facilitate play in the classroom. Discusses the complexity of play and the controversy about play as part of the curriculum. (GLR)

  20. Effects of location and timing of co-activated neurons in the auditory midbrain on cortical activity: implications for a new central auditory prosthesis

    NASA Astrophysics Data System (ADS)

    Straka, Małgorzata M.; McMahon, Melissa; Markovitz, Craig D.; Lim, Hubert H.

    2014-08-01

    Objective. An increasing number of deaf individuals are being implanted with central auditory prostheses, but their performance has generally been poorer than for cochlear implant users. The goal of this study is to investigate stimulation strategies for improving hearing performance with a new auditory midbrain implant (AMI). Previous studies have shown that repeated electrical stimulation of a single site in each isofrequency lamina of the central nucleus of the inferior colliculus (ICC) causes strong suppressive effects in elicited responses within the primary auditory cortex (A1). Here we investigate if improved cortical activity can be achieved by co-activating neurons with different timing and locations across an ICC lamina and if this cortical activity varies across A1. Approach. We electrically stimulated two sites at different locations across an isofrequency ICC lamina using varying delays in ketamine-anesthetized guinea pigs. We recorded and analyzed spike activity and local field potentials across different layers and locations of A1. Results. Co-activating two sites within an isofrequency lamina with short inter-pulse intervals (<5 ms) could elicit cortical activity that is enhanced beyond a linear summation of activity elicited by the individual sites. A significantly greater extent of normalized cortical activity was observed for stimulation of the rostral-lateral region of an ICC lamina compared to the caudal-medial region. We did not identify any location trends across A1, but the most cortical enhancement was observed in supragranular layers, suggesting further integration of the stimuli through the cortical layers. Significance. The topographic organization identified by this study provides further evidence for the presence of functional zones across an ICC lamina with locations consistent with those identified by previous studies. Clinically, these results suggest that co-activating different neural populations in the rostral-lateral ICC rather

  1. The coactivator dTAF(II)110/hTAF(II)135 is sufficient to recruit a polymerase complex and activate basal transcription mediated by CREB.

    PubMed

    Felinski, E A; Quinn, P G

    2001-11-01

    A specific TATA binding protein-associated factor (TAF), dTAF(II)110/hTAF(II)135, interacts with cAMP response element binding protein (CREB) through its constitutive activation domain (CAD), which recruits a polymerase complex and activates transcription. The simplest explanation is that the TAF is a coactivator, but several studies have questioned this role of TAFs. Using a reverse two-hybrid analysis in yeast, we previously mapped the interaction between dTAF(II)110 (amino acid 1-308) and CREB to conserved hydrophobic amino acid residues in the CAD. That mapping was possible only because CREB fails to activate transcription in yeast, where all TAFs are conserved, except for the TAF recognizing CREB. To test whether CREB fails to activate transcription in yeast because it lacks a coactivator, we fused dTAF(II)110 (amino acid 1-308) to the TATA binding protein domain of the yeast scaffolding TAF, yTAF(II)130. Transformation of yeast with this hybrid TAF conferred activation by the CAD, indicating that interaction with yTFIID is sufficient to recruit a polymerase complex and activate transcription. The hybrid TAF did not mediate activation by VP16 or vitamin D receptor, each of which interacts with TFIIB, but not with dTAF(II)110 (amino acid 1-308). Enhancement of transcription activation by dTAF(II)110 in mammalian cells required interaction with both the CAD and TFIID and was inhibited by mutation of core hydrophobic residues in the CAD. These data demonstrate that dTAF(II)110/hTAF(II)135 acts as a coactivator to recruit TFIID and polymerase and that this mechanism of activation is conserved in eukaryotes. PMID:11687654

  2. Cardiopulmonary changes during clarinet playing.

    PubMed

    Hahnengress, Maria L; Böning, Dieter

    2010-12-01

    Since playing wind instrument impedes normal respiratory functions, its effect on expiratory and blood gases as well as on cardiac function was investigated. In 15 skilled clarinettists expiratory PO(2) and PCO(2) were measured in gas drawn from a modified clarinet barrel when playing a composition (Robert Schumann's "Phantasiestücke" Op. 73 for clarinet and piano) with increasing difficulty from movement 1 to movement 3. Blood gases were measured in arterialized ear lobe blood at the end of each movement and the electrocardiogram was recorded continuously. From the expiratory gas pressures one may conclude that the most advanced players adapt their ventilation to the requirements of the composition and sustain expiration during difficult parts of the composition until hypoxic alveolar PO(2) values are reached (minimum 77 mmHg). Less trained clarinettists tend to hyperventilation or shallow breathing. Oxygen saturation in arterialized blood showed a slight step-wise decrease from movement to movement [control 96.6 ± 0.5 (SD)%, end of concert 95.6 ± 1.0%]. SO(2) was significantly higher because of possibly more effective ventilation in instrumentalists with practise time exceeding 2 h daily. Mean heart rate increased to values like during moderate to heavy physical exercise depending on artistic fitness and the difficulty of the movement (maximal individual value 173 beats/min). Additionally, a large variation might be caused through intrathoracic pressure changes, changing exertion, respiratory influences and emotion. The electrocardiogram showed no pathological events. In general, clarinet playing at a professional level imposes strain on ventilation and circulation but usually not on a pathophysiological level. PMID:20734060

  3. Structure-guided optimization of small molecules inhibiting human immunodeficiency virus 1 Tat association with the human coactivator p300/CREB binding protein-associated factor.

    PubMed

    Pan, Chongfeng; Mezei, Mihaly; Mujtaba, Shiraz; Muller, Michaela; Zeng, Lei; Li, Jiaming; Wang, Zhiyong; Zhou, Ming-Ming

    2007-05-17

    Human immunodeficiency virus 1 (HIV-1) trans-activator Tat recruits the human transcriptional coactivator PCAF (p300/CREB binding protein-associated factor) to facilitate transcription of the integrated HIV-1 provirus. We report here structure-based lead optimization of small-molecule inhibitors that block selectively Tat and PCAF association in cells. Our lead optimization was guided by grand-canonical ensemble simulation of the receptor/lead complex that leads to definition of chemical modifications with improved lead affinity through displacing weakly bound water molecules at the ligand-receptor interface. PMID:17444627

  4. Oedipus: history, legends, plays, complexes.

    PubMed

    Kanzer, M

    A discussion of "Oedipus Was Not the Son of Laius and Jocasta" by Angel Garma, M.D. The thesis that Oedipus was not the son of the Theban royal pair but his Corinthian "foster parents" raises questions as to which Oedipus is under discussion--one of several different "historical" and legendary accounts, the hero of the plays of Sophocles, or the synthesized "Oedipuses" of millions of individual and ethnic fantasies. Oedipuses, in whom the particular variant described by Dr. Garma can be discerned, certainly abound and should be included among the many possibilities to be considered. PMID:738818

  5. Supervising the uncanny: the play within the play.

    PubMed

    Leader, Carol

    2015-11-01

    The writer offers a combined experience in analysis and the performing arts to explore uncanny aspects of the unconscious subtext of the patient's inner drama; subtext which can remain hidden from view in supervision. Freud and Jung's understanding of uncanny experience is considered together with a painting from medieval alchemy and Matte Blanco's conceptions concerning the symmetrical nature of unconscious process. Theatre and the work of the theatre director and actor in approaching the multidimensional aspects of a play are then introduced. Finally clinical case material from group supervision demonstrates how the 'theatre of therapy' and the work of the supervisory couple and group promote the emergence of a more authentic conscious asymmetrical response to the patient's 'script' that can break the 'spell' of the transference/countertransference relationship. This in turn brings meaning to the underlying and implicit 'stage directions' that the patient has been unconsciously communicating. PMID:26499298

  6. miR-696 plays a role in hepatic gluconeogenesis in ob/ob mice by targeting PGC-1α.

    PubMed

    Fang, Zhijuan; Li, Peng; Jia, Wenhui; Jiang, Ting; Wang, Zhongyun; Xiang, Yang

    2016-09-01

    MicroRNAs (miRNAs or miRs) are known to play a vital role in type 2 diabetes, and peroxisome proliferator-activated receptor-γ (PPARγ) coactivator-1α (PGC-1α) is involved in the pathogenesis of hepatic insulin resistance. However, the correlation, if any, between PGC-1α and miRNAs in the disease has not yet been determined. Thus, in the present study, we aimed to examine the correlation between PGC-1α and miRNAs in diabetes. For this purpose, we used primary hepatocytes isolated from C57BL/6 mice and ob/ob mice. First, we found an inverse correlation between miR‑696 and PGC-1α protein levels in vivo. Second, in vitro evidence demonstrated that PGC-1α expression was significantly decreased by infection with pre-miR‑696-LV, whereas infection with anti-miR‑696-LV increased the PGC-1α protein levels. Third, a luciferase reporter assay confirmed that miR‑696 directly recognizes a specific location within the 3'-untranslated region of PGC-1α transcripts. Furthermore, the biological consequences of miR‑696 targeting PGC-1α were determined by measuring the expression levels of the characteristic hepatic gluconeogenic enzyme, PEPCK, which is regulated by PGC-1α in the liver via the coactivation of transcription factors. Taken together, our findings demonstrate that miR‑696 plays an important role in the development of hepatic gluconeogenesis and insulin resistance through the inhibition of PGC-1α translation in the liver. PMID:27432632

  7. Drought prediction using co-active neuro-fuzzy inference system, validation, and uncertainty analysis (case study: Birjand, Iran)

    NASA Astrophysics Data System (ADS)

    Memarian, Hadi; Pourreza Bilondi, Mohsen; Rezaei, Majid

    2015-06-01

    This work aims to assess the capability of co-active neuro-fuzzy inference system (CANFIS) for drought forecasting of Birjand, Iran through the combination of global climatic signals with rainfall and lagged values of Standardized Precipitation Index (SPI) index. Using stepwise regression and correlation analyses, the signals NINO 1 + 2, NINO 3, Multivariate Enso Index, Tropical Southern Atlantic index, Atlantic Multi-decadal Oscillation index, and NINO 3.4 were recognized as the effective signals on the drought event in Birjand. Based on the results from stepwise regression analysis and regarding the processor limitations, eight models were extracted for further processing by CANFIS. The metrics P-factor and D-factor were utilized for uncertainty analysis, based on the sequential uncertainty fitting algorithm. Sensitivity analysis showed that for all models, NINO indices and rainfall variable had the largest impact on network performance. In model 4 (as the model with the lowest error during training and testing processes), NINO 1 + 2(t-5) with an average sensitivity of 0.7 showed the highest impact on network performance. Next, the variables rainfall, NINO 1 + 2(t), and NINO 3(t-6) with the average sensitivity of 0.59, 0.28, and 0.28, respectively, could have the highest effect on network performance. The findings based on network performance metrics indicated that the global indices with a time lag represented a better correlation with El Niño Southern Oscillation (ENSO). Uncertainty analysis of the model 4 demonstrated that 68 % of the observed data were bracketed by the 95PPU and D-Factor value (0.79) was also within a reasonable range. Therefore, the fourth model with a combination of the input variables NINO 1 + 2 (with 5 months of lag and without any lag), monthly rainfall, and NINO 3 (with 6 months of lag) and correlation coefficient of 0.903 (between observed and simulated SPI) was selected as the most accurate model for drought forecasting using CANFIS

  8. Drought prediction using co-active neuro-fuzzy inference system, validation, and uncertainty analysis (case study: Birjand, Iran)

    NASA Astrophysics Data System (ADS)

    Memarian, Hadi; Pourreza Bilondi, Mohsen; Rezaei, Majid

    2016-08-01

    This work aims to assess the capability of co-active neuro-fuzzy inference system (CANFIS) for drought forecasting of Birjand, Iran through the combination of global climatic signals with rainfall and lagged values of Standardized Precipitation Index (SPI) index. Using stepwise regression and correlation analyses, the signals NINO 1 + 2, NINO 3, Multivariate Enso Index, Tropical Southern Atlantic index, Atlantic Multi-decadal Oscillation index, and NINO 3.4 were recognized as the effective signals on the drought event in Birjand. Based on the results from stepwise regression analysis and regarding the processor limitations, eight models were extracted for further processing by CANFIS. The metrics P-factor and D-factor were utilized for uncertainty analysis, based on the sequential uncertainty fitting algorithm. Sensitivity analysis showed that for all models, NINO indices and rainfall variable had the largest impact on network performance. In model 4 (as the model with the lowest error during training and testing processes), NINO 1 + 2(t-5) with an average sensitivity of 0.7 showed the highest impact on network performance. Next, the variables rainfall, NINO 1 + 2(t), and NINO 3(t-6) with the average sensitivity of 0.59, 0.28, and 0.28, respectively, could have the highest effect on network performance. The findings based on network performance metrics indicated that the global indices with a time lag represented a better correlation with El Niño Southern Oscillation (ENSO). Uncertainty analysis of the model 4 demonstrated that 68 % of the observed data were bracketed by the 95PPU and D-Factor value (0.79) was also within a reasonable range. Therefore, the fourth model with a combination of the input variables NINO 1 + 2 (with 5 months of lag and without any lag), monthly rainfall, and NINO 3 (with 6 months of lag) and correlation coefficient of 0.903 (between observed and simulated SPI) was selected as the most accurate model for drought forecasting using CANFIS

  9. Reduced expression of peroxisome-proliferator activated receptor gamma coactivator-1α enhances α-synuclein oligomerization and down regulates AKT/GSK3β signaling pathway in human neuronal cells that inducibly express α-synuclein

    PubMed Central

    Ebrahim, Abdul Shukkur; Ko, Li-wen; Yen, Shu-Hui

    2010-01-01

    Intracellular accumulation of filamentous α-synuclein (α-Syn) aggregates to form Lewy bodies is a pathologic hallmark of Parkinson’s disease. To determine whether mitochondrial impairment plays a role in accumulation of α-Syn oligomer, we used 3D5 cell culture model of human neuronal type whereby conditional overexpression of wild-type α-Syn via the tetracycline off (TetOff) induction mechanism results in formation of inclusions that exhibit many characteristics of Lewy bodies. In the present study, we compromised mitochondrial function in 3D5 cells by using shRNA to knockdown peroxisome-proliferator activated receptor gamma coactivator-1α (PGC-1α), a key regulator of mitochondrial biogenesis and cellular energy metabolism and found that PGC-1α suppression at both protein and mRNA levels results in α-Syn accumulation (i.e. monomeric and oligomeric species in the TetOff-induced cells and monomeric only in the non-induced). These changes were accompanied with reduced mitochondrial potential as well as decreased levels of AKT, GSK3β (total and Ser9-phosphorylated) and p53 that are important for cell survival. The extent to which these proteins decreased following PGC-1α knockdown, in contrast to what was demonstrable with the viability assay, is greater in the induced than the non-induced. Together these findings indicate that such knockdown increases the propensity to accumulate α-Syn oligomers, but the accumulation appears to have very little toxic impact to the neuronal cells. PMID:20178833

  10. A Transcription Factor γMYB1 Binds to the P1BS cis-Element and Activates PLA2-γ Expression with its Co-Activator γMYB2.

    PubMed

    Nguyen, Ha Thi Kim; Kim, Soo Youn; Cho, Kwang-Moon; Hong, Jong Chan; Shin, Jeong Sheop; Kim, Hae Jin

    2016-04-01

    Phospholipase A2(PLA2) hydrolyzes phospholipid molecules to produce two products that are both precursors of second messengers of signaling pathways and signaling molecules per se.Arabidopsis thaliana PLA2 paralogs (-β,-γ and -δ) play critical roles during pollen development, pollen germination and tube growth. In this study, analysis of the PLA2-γ promoter using a deletion series revealed that the promoter region -153 to -1 is crucial for its pollen specificity. Using a yeast one-hybrid screening assay with the PLA2-γ promoter and an Arabidopsis transcription factor (TF)-only library, we isolated two novel MYB-like TFs belonging to the MYB-CC family, denoted here as γMYB1 and γMYB2. By electrophoretic mobility shift assay, we found that these two TFs bind directly to the P1BS (phosphate starvation response 1-binding sequence)cis-element of the PLA2-γ promoter. γMYB1 alone functioned as a transcriptional activator for PLA2-γ expression, whereas γMYB2 directly interacted with γMYB1 and enhanced its activation. Overexpression of γMYB1 in the mature pollen grain led to increased expression of not only the PLA2-γ gene but also of several genes whose promoters contain the P1BS cis-element and which are involved in the Pi starvation response, phospholipid biosynthesis and sugar synthesis. Based on these results, we suggest that the TF γMYB1 binds to the P1BS cis-element, activates the expression of PLA2-γ with the assistance of its co-activator, γMYB2, and regulates the expression of several target genes involved in many plant metabolic reactions. PMID:26872838

  11. Play for All. [CD-ROM].

    ERIC Educational Resources Information Center

    Moore, Robin C.; Goltsman, Susan M.

    A CD-ROM provides a tour of some of the world's greatest play environments, presenting 94 photographic images that illustrate the key concepts and recommendations from Play For All guidelines. It is organized into 10 categories covering a range of play area settings, including play equipment, sand settings, water settings, play props, and animal…

  12. Caring About Kids: The Importance of Play.

    ERIC Educational Resources Information Center

    National Inst. of Mental Health (DHHS), Rockville, MD. Div. of Scientific and Public Information.

    In several brief sections, this pamphlet defines play, discusses how play helps a child develop, and how play changes as a child grows older, indicates the role of toys and certain play activities in promoting sex stereotypes, and identifies the role of fantasy and imagination in children's play. A discussion of the role of parents in fostering…

  13. Play Therapy: Voice of a Silent Scream

    ERIC Educational Resources Information Center

    Rakesh, Annuradha; H, Uma; Srinath, Shoba

    2010-01-01

    Play Therapy is based upon the fact that play is the child's natural medium of self-expression. It is an opportunity that is given to the child to "play out" his/her feelings and problems just as, in certain types of adult therapy, an individual "talks out" his difficulties. Children use play to express feelings and thoughts. Play emerges from the…

  14. Why do phage play dice?

    PubMed

    Avlund, Mikkel; Dodd, Ian B; Semsey, Szabolcs; Sneppen, Kim; Krishna, Sandeep

    2009-11-01

    Phage lambda is among the simplest organisms that make a developmental decision. An infected bacterium goes either into the lytic state, where the phage particles rapidly replicate and eventually lyse the cell, or into a lysogenic state, where the phage goes dormant and replicates along with the cell. Experimental observations by P. Kourilsky are consistent with a single phage infection deterministically choosing lysis and double infection resulting in a stochastic choice. We argue that the phage are playing a "game" of minimizing the chance of extinction and that the shift from determinism to stochasticity is due to a shift from a single-player to a multiplayer game. Crucial to the argument is the clonal identity of the phage. PMID:19740995

  15. Hand kinematics of piano playing

    PubMed Central

    Flanders, Martha; Soechting, John F.

    2011-01-01

    Dexterous use of the hand represents a sophisticated sensorimotor function. In behaviors such as playing the piano, it can involve strong temporal and spatial constraints. The purpose of this study was to determine fundamental patterns of covariation of motion across joints and digits of the human hand. Joint motion was recorded while 5 expert pianists played 30 excerpts from musical pieces, which featured ∼50 different tone sequences and fingering. Principal component analysis and cluster analysis using an expectation-maximization algorithm revealed that joint velocities could be categorized into several patterns, which help to simplify the description of the movements of the multiple degrees of freedom of the hand. For the thumb keystroke, two distinct patterns of joint movement covariation emerged and they depended on the spatiotemporal patterns of the task. For example, the thumb-under maneuver was clearly separated into two clusters based on the direction of hand translation along the keyboard. While the pattern of the thumb joint velocities differed between these clusters, the motions at the metacarpo-phalangeal and proximal-phalangeal joints of the four fingers were more consistent. For a keystroke executed with one of the fingers, there were three distinct patterns of joint rotations, across which motion at the striking finger was fairly consistent, but motion of the other fingers was more variable. Furthermore, the amount of movement spillover of the striking finger to the adjacent fingers was small irrespective of the finger used for the keystroke. These findings describe an unparalleled amount of independent motion of the fingers. PMID:21880938

  16. Hand kinematics of piano playing.

    PubMed

    Furuya, Shinichi; Flanders, Martha; Soechting, John F

    2011-12-01

    Dexterous use of the hand represents a sophisticated sensorimotor function. In behaviors such as playing the piano, it can involve strong temporal and spatial constraints. The purpose of this study was to determine fundamental patterns of covariation of motion across joints and digits of the human hand. Joint motion was recorded while 5 expert pianists played 30 excerpts from musical pieces, which featured ∼50 different tone sequences and fingering. Principal component analysis and cluster analysis using an expectation-maximization algorithm revealed that joint velocities could be categorized into several patterns, which help to simplify the description of the movements of the multiple degrees of freedom of the hand. For the thumb keystroke, two distinct patterns of joint movement covariation emerged and they depended on the spatiotemporal patterns of the task. For example, the thumb-under maneuver was clearly separated into two clusters based on the direction of hand translation along the keyboard. While the pattern of the thumb joint velocities differed between these clusters, the motions at the metacarpo-phalangeal and proximal-phalangeal joints of the four fingers were more consistent. For a keystroke executed with one of the fingers, there were three distinct patterns of joint rotations, across which motion at the striking finger was fairly consistent, but motion of the other fingers was more variable. Furthermore, the amount of movement spillover of the striking finger to the adjacent fingers was small irrespective of the finger used for the keystroke. These findings describe an unparalleled amount of independent motion of the fingers. PMID:21880938

  17. Chin force in violin playing.

    PubMed

    Obata, Satoshi; Kinoshita, Hiroshi

    2012-06-01

    Force generated between the left mandible of violinists and the chinrest of the violin was examined using a force-sensing chinrest developed in this study. A strain-gauge force sensor was built, and it was fixed between the violin's top plate and a chin cup. Fifteen professional/amateur violinists held the violin statically, played musical scales with different sound properties and sounding techniques, as well as an excerpt from a Max Bruch concerto. Peak and mean forces were evaluated for each task. In a separate experiment, lateral movement of the lower teeth due to different levels of voluntary chin force exertion was measured. Static holding forces observed were 15 and 22 N with and without the help of the left hand, respectively. Peak force increased from 16 N at soft dynamics to 20 N at strong dynamics during scales. The force further increased to 29 N with the use of vibrato technique and 35 N during shifts. Tempo and hand position did not affect the force. Playing a Bruch concerto induced a mean peak force of 52 N, ranging from 31 to 82 N among the violinists. The developed force-sensing chinrest could accurately record the generated chin force. Typical chin force to stabilize the violin during ordinary musical performance was less than 30 N, but it could momentarily exceed 50 N when technically demanding musical pieces were performed. The lateral shift of the mandible was fairly small (<0.4 mm) even with high chin-force exertion, possibly due to clenching of the molars. PMID:21952980

  18. Androgen receptor co-activator Hic-5/ARA55 as a molecular regulator of androgen sensitivity in dermal papilla cells of human hair follicles.

    PubMed

    Inui, Shigeki; Fukuzato, Yoko; Nakajima, Takeshi; Kurata, Sotaro; Itami, Satoshi

    2007-10-01

    Androgen site-specifically affects human hair growth after puberty through androgen receptors in the dermal papilla, which transactivate target genes acting in conjunction with co-activators. To examine the regulation of androgen sensitivity in hair follicles, we focused on androgen receptor co-activator Hic-5/ARA55. Its interaction with transfected androgen receptor in beard dermal papilla cells was confirmed with mammalian two-hybrid assays. The semiquantitative reverse transcriptase-polymerase chain reaction showed that Hic-5/ARA55 mRNA expression was high in dermal papilla cells from the beard and bald frontal scalp but low in cells from the occipital scalp. To determine whether Hic-5/ARA55 mRNA level correlates with its endogenous activity, we studied the effect of dominant negative Hic-5/ARA55 on transfected androgen receptor transactivation induced by R1881 using mouse mammary tumor virus-luciferase assays. We found that it suppressed the transactivation by 64.5 and 71.4% in dermal papilla cells from the beard and bald frontal scalp, respectively, whereas it showed no significant effect in cells from the occipital scalp. Our findings suggest that Hic-5/ARA55 is a molecular regulator for androgen sensitivity in human hair follicles. PMID:17508020

  19. Analysis of PGC-1{alpha} variants Gly482Ser and Thr612Met concerning their PPAR{gamma}2-coactivation function

    SciTech Connect

    Nitz, Inke . E-mail: initz@molnut.uni-kiel.de; Ewert, Agnes; Klapper, Maja; Doering, Frank

    2007-02-09

    Peroxisome proliferator-activated receptor-{gamma} coactivator-1{alpha} (PGC-1{alpha}) is a cofactor involved in adaptive thermogenesis, fatty acid oxidation, and gluconeogenesis. Dysfunctions of this protein are likely to contribute to the development of obesity and the metabolic syndrome. This is in part but not definitely confirmed by results of population studies. The aim of this study was to investigate if common genetic variants rs8192678 (Gly482Ser) and rs3736265 (Thr612Met) in the PGC-1{alpha} gene lead to a functional consequence in cofactor activity using peroxisome proliferator-activated receptor-{gamma} 2 (PPAR{gamma}2) as interacting transcription factor. Reporter gene assays in HepG2 cells with wildtype and mutant proteins of both PGC1{alpha} and PPAR{gamma}2 (Pro12Ala, rs1801282) using the acyl-CoA-binding protein (ACBP) promoter showed no difference in coactivator activity. This is First study implicating that the Gly482Ser and Thr612Met polymorphisms in PGC-1{alpha} and Pro12Ala polymorphism in PPAR{gamma}2 do not affect the functional integrity of these proteins.

  20. The Human Papillomavirus Type 16 E6 Oncoprotein Can Down-Regulate p53 Activity by Targeting the Transcriptional Coactivator CBP/p300

    PubMed Central

    Zimmermann, Holger; Degenkolbe, Roland; Bernard, Hans-Ulrich; O’Connor, Mark J.

    1999-01-01

    The transforming proteins of the small DNA tumor viruses, simian virus 40 (SV40), adenovirus, and human papillomavirus (HPV) target a number of identical cellular regulators whose functional abrogation is required for transformation. However, while both adenovirus E1A and SV40 large T transforming properties also depend on the targeting of the transcriptional coactivator CBP/p300, no such interaction has been described for the HPV oncoprotein E6 or E7. Here, we demonstrate that the HPV-16 E6 protein, previously shown to facilitate the degradation of p53 in a complex with E6-associated protein (E6AP), also targets CBP/p300 in an interaction involving the C-terminal zinc finger of E6 and CBP residues 1808 to 1826. Furthermore, this interaction is limited to E6 proteins of high-risk HPVs associated with cervical cancer that have the capacity to repress p53-dependent transcription. An HPV-16 E6 mutant (L50G) that binds CBP/p300, but not E6AP, is still capable of down-regulating p53 transcriptional activity. Thus, HPV E6 proteins possess two distinct mechanisms by which to abrogate p53 function: the repression of p53 transcriptional activity by targeting the p53 coactivator CBP/p300, and the removal of cellular p53 protein through the proteosome degradation pathway. PMID:10400710

  1. T cell factor-4 functions as a co-activator to promote NF-κB-dependent MMP-15 expression in lung carcinoma cells.

    PubMed

    Liu, Yuliang; Xu, Yu; Guo, Shuliang; Chen, Hong

    2016-01-01

    Both TCF-4 and MMP-15 are closely linked to the development of lung cancer, while the regulatory role of TCF-4 in MMP-15 expression is still obscure. Here we found that expression of TCF-4 and MMP-15 was increased in lung cancer cells or tissues versus the normal ones. With gain-or loss-of -function studies, we demonstrated that TCF-4 positively regulated MMP-15 expression in mRNA and protein levels. With reporter gene assay, we found that TCF-4 regulated MMP-15 expression via a potential NF-κB binding element locating at -2833/-2824 in the mouse MMP-15 promoter. With ChIP and immunoblotting assays, we identified that TCF-4 functioned as a co-activator to potentiate the binding between p65 and MMP-15 promoter. Functionally, TCF-4 silence attenuated the migration activity of LLC cells, while additional overexpression of MMP-15 rescued this effect in cell scratch test and transwell migration assay. In xenograft model, TCF-4 silence-improved tumor lesions in lungs and survival time of LLC-tumor bearing mice were abolished by MMP-15 overexpression. In conclusion, we are the first to identify TCF-4 as a co-activator of NF-κB p65 to promote MMP-15 transcription and potentiate the migration activity of the lung cancer cells. Our findings shed light on the therapeutic strategies of this malignancy. PMID:27046058

  2. T cell factor-4 functions as a co-activator to promote NF-κB-dependent MMP-15 expression in lung carcinoma cells

    PubMed Central

    Liu, Yuliang; Xu, Yu; Guo, Shuliang; Chen, Hong

    2016-01-01

    Both TCF-4 and MMP-15 are closely linked to the development of lung cancer, while the regulatory role of TCF-4 in MMP-15 expression is still obscure. Here we found that expression of TCF-4 and MMP-15 was increased in lung cancer cells or tissues versus the normal ones. With gain-or loss-of -function studies, we demonstrated that TCF-4 positively regulated MMP-15 expression in mRNA and protein levels. With reporter gene assay, we found that TCF-4 regulated MMP-15 expression via a potential NF-κB binding element locating at -2833/-2824 in the mouse MMP-15 promoter. With ChIP and immunoblotting assays, we identified that TCF-4 functioned as a co-activator to potentiate the binding between p65 and MMP-15 promoter. Functionally, TCF-4 silence attenuated the migration activity of LLC cells, while additional overexpression of MMP-15 rescued this effect in cell scratch test and transwell migration assay. In xenograft model, TCF-4 silence-improved tumor lesions in lungs and survival time of LLC-tumor bearing mice were abolished by MMP-15 overexpression. In conclusion, we are the first to identify TCF-4 as a co-activator of NF-κB p65 to promote MMP-15 transcription and potentiate the migration activity of the lung cancer cells. Our findings shed light on the therapeutic strategies of this malignancy. PMID:27046058

  3. A liver X receptor (LXR)-{beta} alternative splicing variant (LXRBSV) acts as an RNA co-activator of LXR-{beta}

    SciTech Connect

    Hashimoto, Koshi; Ishida, Emi; Matsumoto, Shunichi; Shibusawa, Nobuyuki; Okada, Shuichi; Monden, Tsuyoshi; Satoh, Tetsurou; Yamada, Masanobu; Mori, Masatomo

    2009-12-25

    We report the isolation and functional characterization of a novel transcriptional co-activator, termed LXRBSV. LXRBSV is an alternative splicing variant of liver X receptor (LXR)-{beta} LXRBSV has an intronic sequence between exons 2 and 3 in the mouse LXR-{beta} gene. The LXRBSV gene is expressed in various tissues including the liver and brain. We sub-cloned LXRBSV into pSG5, a mammalian expression vector, and LXRBSV in pSG5 augmented human Sterol Response Element Binding Protein (SREBP)-1c promoter activity in HepG2 cells in a ligand (TO901317) dependent manner. The transactivation mediated by LXRBSV is selective for LXR-{beta}. The LXRBSV protein was deduced to be 64 amino acids in length; however, a GAL4-LXRBSV fusion protein was not able to induce transactivation. Serial deletion constructs of LXRBSV demonstrated that the intronic sequence inserted in LXRBSV is required for its transactivation activity. An ATG mutant of LXRBSV was able to induce transactivation as wild type. Furthermore, LXRBSV functions in the presence of cycloheximide. Taken together, we have concluded that LXRBSV acts as an RNA transcript not as a protein. In the current study, we have demonstrated for the first time that an alternative splicing variant of a nuclear receptor acts as an RNA co-activator.

  4. Knockdown of peroxisome proliferator-activated receptor gamma coactivator-1 alpha increased apoptosis of human endometrial cancer HEC-1A cells

    PubMed Central

    Yang, Hui; Yang, Rui; Liu, Hao; Ren, Zhongqian; Wang, Cuicui; Li, Da; Ma, Xiaoxin

    2016-01-01

    Background Peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) coactivates multiple transcription factors and regulates several metabolic processes. In this study, we focused on the roles of PGC-1α in the apoptosis of endometrial cancer HEC-1A cells. Materials and methods PGC-1a expression in the HEC-1A cells was detected with real-time polymerase chain reaction and Western blot. Small interfering RNA directed against PGC-1α was designed and synthesized, and RNA interference technology was used to knock down PGC-1α mRNA and protein expression. Cell apoptosis, cell cycle, and mitochondrial membrane potential were then analyzed using flow cytometry. The expression of apoptotic proteins, Bcl-2 and Bax, was detected with Western blot. Results The specific downregulation of PGC-1α expression in the HEC-1A cells increased their apoptosis through the mitochondrial apoptotic pathway by reducing the expression of Bcl-2 and increasing the expression of Bax. Conclusion These results suggest that PGC-1α influences the apoptosis of HEC-1A cells and also provides a molecular basis for further investigation of the apoptotic mechanism in human endometrial cancer. PMID:27601924

  5. Adeno-associated virus type 2 rep protein inhibits human papillomavirus type 16 E2 recruitment of the transcriptional coactivator p300.

    PubMed

    Marcello, A; Massimi, P; Banks, L; Giacca, M

    2000-10-01

    Infection by human adeno-associated virus type 2 (AAV2) is a possible protective factor in the development of cervical carcinomas associated with human papillomaviruses (HPV). The replicative proteins of AAV2 (Rep) have been implicated in the inhibition of papillomavirus replication and transforming activities, although the molecular events underlying these effects are poorly understood. We observed that each of the four forms of AAV2 Rep inhibited the E1- and E2-driven replication of oncogenic HPV type 16 (HPV16). Rep40, corresponding to the C-terminal domain of all Rep proteins, inhibited both HPV DNA replication and HPV16 E2-mediated transactivation. Rep40 specifically bound the N-terminal transactivation domain of HPV16 E2 both in vitro and in vivo. This interaction was found to specifically disrupt the binding of E2 to the cellular transcriptional coactivator p300. Accordingly, the inhibitory effect of Rep on HPV16 E2 transactivation was rescued by the overexpression of p300. These data indicate a novel role of Rep in the down-regulation of papillomaviruses through inhibition of complex formation between the HPV16 E2 transcriptional activator and its cellular coactivator, p300. PMID:10982355

  6. Cysteine S-Glutathionylation Promotes Stability and Activation of the Hippo Downstream Effector Transcriptional Co-activator with PDZ-binding Motif (TAZ).

    PubMed

    Gandhirajan, Rajesh Kumar; Jain, Manaswita; Walla, Benedikt; Johnsen, Marc; Bartram, Malte P; Huynh Anh, Minh; Rinschen, Markus M; Benzing, Thomas; Schermer, Bernhard

    2016-05-27

    Transcriptional co-activator with PDZ-binding motif (TAZ) and Yes-associated protein (YAP) are critical transcriptional co-activators downstream of the Hippo pathway involved in the regulation of organ size, tissue regeneration, proliferation, and apoptosis. Recent studies suggested common and distinct functions of TAZ and YAP and their diverse impact under several pathological conditions. Here we report differential regulation of TAZ and YAP in response to oxidative stress. H2O2 exposure leads to increased stability and activation of TAZ but not of YAP. H2O2 induces reversible S-glutathionylation at conserved cysteine residues within TAZ. We further demonstrate that TAZ S-glutathionylation is critical for reactive oxygen species (ROS)-mediated, TAZ-dependent TEA domain transcription factor (TEAD) trans-activation. Lysophosphatidic acid, a physiological activator of YAP and TAZ, induces ROS elevation and, subsequently, TAZ S-glutathionylation, which promotes TAZ-mediated target gene expression. TAZ expression is essential for renal homeostasis in mice, and we identify basal TAZ S-glutathionylation in murine kidney lysates, which is elevated during ischemia/reperfusion injury in vivo This induced nuclear localization of TAZ and increased expression of connective tissue growth factor. These results describe a novel mechanism by which ROS sustains total cellular levels of TAZ. This preferential regulation suggests TAZ to be a redox sensor of the Hippo pathway. PMID:27048650

  7. Superhero Play: What's a Teacher to Do?

    ERIC Educational Resources Information Center

    Bauer, Karen L.; Dettore, Ernest

    1997-01-01

    Examines the appeal of superheroes to children and adults' beliefs about superhero play, and suggests some potential benefits of such play. Offers examples of ways to successfully incorporate superhero play into an early childhood classroom. (Author/KB)

  8. Finger Forces in Clarinet Playing

    PubMed Central

    Hofmann, Alex; Goebl, Werner

    2016-01-01

    Clarinettists close and open multiple tone holes to alter the pitch of the tones. Their fingering technique must be fast, precise, and coordinated with the tongue articulation. In this empirical study, finger force profiles and tongue techniques of clarinet students (N = 17) and professional clarinettists (N = 6) were investigated under controlled performance conditions. First, in an expressive-performance task, eight selected excerpts from the first Weber Concerto were performed. These excerpts were chosen to fit in a 2 × 2 × 2 design (register: low–high; tempo: slow–fast, dynamics: soft–loud). There was an additional condition controlled by the experimenter, which determined the expression levels (low–high) of the performers. Second, a technical-exercise task, an isochronous 23-tone melody was designed that required different effectors to produce the sequence (finger-only, tongue-only, combined tongue-finger actions). The melody was performed in three tempo conditions (slow, medium, fast) in a synchronization-continuation paradigm. Participants played on a sensor-equipped Viennese clarinet, which tracked finger forces and reed oscillations simultaneously. From the data, average finger force (Fmean) and peak force (Fmax) were calculated. The overall finger forces were low (Fmean = 1.17 N, Fmax = 3.05 N) compared to those on other musical instruments (e.g., guitar). Participants applied the largest finger forces during the high expression level performance conditions (Fmean = 1.21 N). For the technical exercise task, timing and articulation information were extracted from the reed signal. Here, the timing precision of the fingers deteriorated the timing precision of the tongue for combined tongue-finger actions, especially for faster tempi. Although individual finger force profiles were overlapping, the group of professional players applied less finger force overall (Fmean = 0.54 N). Such sensor instruments provide useful insights into player

  9. Strategies for Family Facilitation of Play Dates

    ERIC Educational Resources Information Center

    Chambers, Cynthia R.; Horn, Eva M.

    2010-01-01

    Play dates can serve several functions for young children, including children with social difficulties, such as developmental delays, behavioral disorders, autism spectrum disorders, and shyness. Play dates provide children with additional opportunities to be around peers and to practice skills associated with peer play interactions. Play dates…

  10. Children, Play, and Development. Fourth Edition

    ERIC Educational Resources Information Center

    Hughes, Fergus P.

    2010-01-01

    Children, Play, and Development, Fourth Edition, discusses the relationship of play to the physical, social, intellectual, and emotional growth of the child. Author Fergus P. Hughes focuses on the historical, sociocultural, and ethological context of play; the role of development in play; and the wide range of theories that provide a framework for…

  11. Play and the Young Child: Musical Implications.

    ERIC Educational Resources Information Center

    Brophy, Tim

    After noting the near-universal presence of rhythmic response in play in all cultures, this paper looks first at the historical development of theories of play, and then examines current theories of play and their implications in the teaching of music to young children. The first section reviews 19th and early 20th century theories of play,…

  12. How the Brain Makes Play Fun

    ERIC Educational Resources Information Center

    Vanderschuren, Louk J. M. J.

    2010-01-01

    In this article, the author describes the empirical studies that have investigated whether play (mostly social play) is rewarding. He then discusses the brain circuits and neurotransmitters that underlie the pleasurable aspects of play. He concludes that the pleasure of play has the ability to reinforce learning activities and that the brain's…

  13. Conceptualizing the Play Policies in Preschool Curriculums

    ERIC Educational Resources Information Center

    Sener, Tulin

    2013-01-01

    This research attempted to describe the play policies in preschool institutions in Ankara, Turkey. The aim of this study is to determine the approaches of the preschools to the children's play. "Play Policy Questionnaire" administered to all directors and teachers of 20 public preschools and 20 private preschools. Play policy of…

  14. Introduction to Plays, English: 5112.44.

    ERIC Educational Resources Information Center

    Ozan, Ruth S.

    Several plays are studied to introduce students to theatrical terms and to the elements of a play in this quinmester course for Dade County High Schools. Several approaches to the study of the play are suggested such as individual and a large group production of a play, the use of a unified theme such as Youth vs. Tradition, or the line of…

  15. Parent-Child Play: Descriptions and Implications.

    ERIC Educational Resources Information Center

    MacDonald, Kevin, Ed.

    This volume provides the latest research and theory in the area of children's play with their parents. It includes discussions of the basic processes involved in parent-child play, parent-child play in atypical populations of children, and parent-child play from a cross-cultural perspective. Fifteen chapters follow the introduction, "Parents and…

  16. Play in Cultural Contexts = Mang Kultuurikontekstis.

    ERIC Educational Resources Information Center

    Saar, Aino, Ed.; Hakkarainen, Pentti, Ed.

    1998-01-01

    This volume compiles articles based on the presentations delivered at two conferences. The conferences presented a multidisciplinary overview of research on children's play in different cultural contexts. The articles are grouped under six subheadings: play in the family context, play in the zone of proximal development, play in the kindergarten,…

  17. Play and Social Interaction in Middle Childhood

    ERIC Educational Resources Information Center

    Bergen, Doris; Fromberg, Doris Pronin

    2009-01-01

    This article discusses traditional and contemporary definitions of middle childhood play, the value of such play for children's development and learning, the implications of home, school, and societal practices that have resulted in changing the play scenario of middle childhood, and suggestions for assuring that play's value will be maintained…

  18. Monitored Play Therapy: Conceptual and Methodological Issues.

    ERIC Educational Resources Information Center

    Golden, Bobbie

    There are many unanswered questions about play therapy. Monitored play therapy is an attempt to discover answers to these questions. The main emphasis is on quantitative recording and analysis of the process and outcome of play therapy. However, because of its newness, monitored play therapy also has some weaknesses. The main strong point is the…

  19. Active Gaming: The Future of Play?

    ERIC Educational Resources Information Center

    Witherspoon, Lisa; Manning, John P.

    2012-01-01

    The authors examine technology-driven games--especially active gaming--as an evolving form of children's play. They offer an overview of play and its developmental benefits, describe the literature on the emergence of technology-driven play, and reflect on the diminishment of physical play in contemporary culture. They suggest that active gaming,…

  20. Reconceptualizing Play: Aesthetic Self-Definitions

    ERIC Educational Resources Information Center

    Guss, Faith

    2005-01-01

    This article aims to trouble the identity of children's dramatic play(ing). It contains two interweaving threads of discourse. In one thread lies a discussion of how children can trouble and extend their own identities through the aesthetic form-languages and conventions they employ and deploy in their dramatic playing/pretend playing.…