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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.

  2. Acetylation of steroidogenic factor 1 protein regulates its transcriptional activity and recruits the coactivator GCN5.

    PubMed

    Jacob, A L; Lund, J; Martinez, P; Hedin, L

    2001-10-01

    Steroidogenic factor-1 (SF-1) is an orphan nuclear receptor that plays an essential role in the development of the hypothalamic-pituitary-gonadal axis in both sexes. SF-1 belongs to the hormone nuclear receptor superfamily and possesses an N-terminal DNA binding domain and a C-terminal ligand binding domain. Activation function domain 2 is located C-terminal of the ligand binding domain of SF-1 and is important for the transactivation of target genes. Coactivators with histone acetyltransferase activity such as cAMP response element-binding protein-binding protein and steroid receptor coactivator 1 interact and increase SF-1-mediated transcriptional activity. In this study we demonstrate that SF-1 is acetylated in vivo. Histone acetyltransferase GCN5 acetylates SF-1 in vitro. Moreover, we found that SF-1 recruited a novel coactivator GCN5, which can be a newly identified coactivator for SF-1. Acetylation of SF-1 stimulates its transcriptional activity. Inhibition of deacetylation by trichostatin A, a histone deacetylase inhibitor, increased SF-1-mediated transactivation and stabilized and induced the nuclear export of the SF-1 protein.

  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.

  4. Lysine Acetyltransferase GCN5b Interacts with AP2 Factors and Is Required for Toxoplasma gondii Proliferation

    PubMed Central

    Wang, Jiachen; Dixon, Stacy E.; Ting, Li-Min; Liu, Ting-Kai; Jeffers, Victoria; Croken, Matthew M.; Calloway, Myrasol; Cannella, Dominique; Ali Hakimi, Mohamed; Kim, Kami; Sullivan, William J.

    2014-01-01

    Histone acetylation has been linked to developmental changes in gene expression and is a validated drug target of apicomplexan parasites, but little is known about the roles of individual histone modifying enzymes and how they are recruited to target genes. The protozoan parasite Toxoplasma gondii (phylum Apicomplexa) is unusual among invertebrates in possessing two GCN5-family lysine acetyltransferases (KATs). While GCN5a is required for gene expression in response to alkaline stress, this KAT is dispensable for parasite proliferation in normal culture conditions. In contrast, GCN5b cannot be disrupted, suggesting it is essential for Toxoplasma viability. To further explore the function of GCN5b, we generated clonal parasites expressing an inducible HA-tagged dominant-negative form of GCN5b containing a point mutation that ablates enzymatic activity (E703G). Stabilization of this dominant-negative GCN5b was mediated through ligand-binding to a destabilization domain (dd) fused to the protein. Induced accumulation of the ddHAGCN5b(E703G) protein led to a rapid arrest in parasite replication. Growth arrest was accompanied by a decrease in histone H3 acetylation at specific lysine residues as well as reduced expression of GCN5b target genes in GCN5b(E703G) parasites, which were identified using chromatin immunoprecipitation coupled with microarray hybridization (ChIP-chip). Proteomics studies revealed that GCN5b interacts with AP2-domain proteins, apicomplexan plant-like transcription factors, as well as a “core complex” that includes the co-activator ADA2-A, TFIID subunits, LEO1 polymerase-associated factor (Paf1) subunit, and RRM proteins. The dominant-negative phenotype of ddHAGCN5b(E703G) parasites, considered with the proteomics and ChIP-chip data, indicate that GCN5b plays a central role in transcriptional and chromatin remodeling complexes. We conclude that GCN5b has a non-redundant and indispensable role in regulating gene expression required during the

  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.

  7. 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

  8. GCN5 is essential for IRF-4 gene expression followed by transcriptional activation of Blimp-1 in immature B cells.

    PubMed

    Kikuchi, Hidehiko; Nakayama, Masami; Kuribayashi, Futoshi; Imajoh-Ohmi, Shinobu; Nishitoh, Hideki; Takami, Yasunari; Nakayama, Tatsuo

    2014-03-01

    During B-cell differentiation, the gene expression of B-cell differentiation-related transcription factors must be strictly controlled by epigenetic mechanisms including histone acetylation and deacetylation, to complete the differentiation pathway. GCN5, one of the most important histone acetyltransferases, is involved in epigenetic events for transcriptional regulation through alterations in the chromatin structure. In this study, by analyzing the homozygous DT40 mutants GCN5(-/-), generated with gene targeting techniques, we found that GCN5 was necessary for transcriptional activation of IRF-4, an essential transcription factor for plasma cell differentiation. GCN5 deficiency caused drastic decreases in both the mRNA and the protein levels of Blimp-1 and IRF-4. The ectopic expression of Blimp-1 and IRF-4 suggests that IRF-4, but not Blimp-1, is the target gene of GCN5 in immature B cells. Moreover, a chromatin immunoprecipitation assay showed that GCN5 bound to the IRF-4 gene around its 5'-flanking region and acetylated H3K9 residues within chromatin surrounding the region in vivo, suggesting that gene expression of IRF-4 is certainly regulated by GCN5. These results reveal that GCN5 is essential for IRF-4 gene expression, followed by transcriptional activation of Blimp-1, and plays a key role in epigenetic regulation of B-cell differentiation.

  9. 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

  10. A role for Gcn5 in cardiomyocyte differentiation of rat mesenchymal stem cells.

    PubMed

    Li, Li; Zhu, Jing; Tian, Jie; Liu, Xiaoyan; Feng, Chuan

    2010-12-01

    MSCs possess the capacity of self-renewal and potential of differentiation into various kinds of specialized tissue cells including myocardiocytes. From self-renewing to oriented differentiation, chromatin is remodeled into heritable states that allow activation or maintain the repression of regulatory genes, which means specific genes in self-renewing switched off and specific genes in oriented differentiation activated (Bernstein et al. Cell 125:315-326, 2006). These epigenetic states are established and controlled largely by specific patterns of histone posttranslational modifications, in particular, histone acetylation (Li Nat Rev Genet 3:662-673, 2002). In cardiomyocyte differentiation of rat MSCs, we focused on Gcn5, which linked a known transcriptional coactivator with catalytic histone acetyltransferase activity (Brownell et al. Cell 84:843-851, 1996). To clarify participatory in vivo role of Gcn5, using an RNA interference (RNAi) strategy employing shRNA to specifically knockdown Gcn5 expression in MSCs, we found that HAT activity altered dynamically depended on the inhibition of Gcn5 during MSCs differentiation. Chromatin immunoprecipitation (ChIP) assay showed the increased binding of acetyl histone H3 to the early cardiomyocyte-specific genes GATA4 and NKx2.5 promoters in cardiomyocyte differentiation of MSCs by 5-azacytidine inducing, whereas the decreased binding with lower Gcn5 expression. Cell ultrastructure analysis revealed that MSCs induced by 5-azacytidine possess morphological characteristics of cardiomyocyte cells. The shape of MSCs transfected by Gcn5 RNAi was similar to normal MSCs, but the chromatin showed heavy electron-density and a hard-packed structure. This intermediate state of chromatin may be an inactive part of MSCs differentiation. These results demonstrate that Gcn5, possessing acetyltransferase activity, is involved in regulating chromatin configuration around GATA4 and NKx2.5 in cardiomyocyte differentiation of rat MSCs by

  11. Histone Acetyltransferase GCN5 Regulates Osteogenic Differentiation of Mesenchymal Stem Cells by Inhibiting NF-κB.

    PubMed

    Zhang, Ping; Liu, Yunsong; Jin, Chanyuan; Zhang, Min; Tang, Fuchou; Zhou, Yongsheng

    2016-02-01

    As the most well-studied histone acetyltransferase (HAT) in yeast and mammals, general control nonderepressible 5 (GCN5) was documented to play essential roles in various developmental processes. However, little is known about its role in osteogenic differentiation of mesenchymal stem cells (MSCs). Here, we detected the critical function of GCN5 in osteogenic commitment of MSCs. In this role, the HAT activity of GCN5 was not required. Mechanistically, GCN5 repressed nuclear factor kappa B (NF-κB)-dependent transcription and inhibited the NF-κB signaling pathway. The impaired osteogenic differentiation by GCN5 knockdown was blocked by inhibition of NF-κB. Most importantly, the expression of GCN5 was decreased significantly in the bone tissue sections of ovariectomized mice or aged mice. Collectively, these results may point to the GCN5-NF-κB pathway as a novel potential molecular target for stem cell mediated regenerative medicine and the treatment of metabolic bone diseases such as osteoporosis.

  12. The histone acetyltransferase PsGcn5 mediates oxidative stress responses and is required for full virulence of Phytophthora sojae.

    PubMed

    Zhao, Wei; Wang, Tao; Liu, Shusen; Chen, Qingqing; Qi, Rende

    2015-10-01

    In eukaryotic organisms, histone acetyltransferase complexes are coactivators that are important for transcriptional activation by modifying chromatin. In this study, a gene (PsGcn5) from Phytophthora sojae encoding a histone acetyltransferase was identified as a homolog of one component of the histone acetyltransferase complex from yeasts to mammals. PsGcn5 was constitutively expressed in each stage tested, but had a slightly higher expression in sporulating hyphae and 3 h after infection. PsGcn5-silenced mutants were generated using polyethylene glycol-mediated protoplast stable transformation. These mutants had normal development, but compared to wild type strains they had higher sensitivity to hydrogen peroxide (H2O2) and significantly reduced virulence in soybean. Diaminobenzidine staining revealed an accumulation of H2O2 around the infection sites of PsGcn5-silenced mutants but not for wild type strains. Inhibition of the plant NADPH oxidase by diphenyleneiodonium prevented host-derived H2O2 accumulation in soybean cells and restored infectious hyphal growth of the mutants. Thus, we concluded that PsGcn5 is important for growth under conditions of oxidative stress and contributes to the full virulence of P. sojae by suppressing the host-derived reactive oxygen species.

  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. 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

  15. Lysine Acetyltransferase GCN5 Potentiates the Growth of Non-small Cell Lung Cancer via Promotion of E2F1, Cyclin D1, and Cyclin E1 Expression*

    PubMed Central

    Chen, Long; Wei, Tingyi; Si, Xiaoxing; Wang, Qianqian; Li, Yan; Leng, Ye; Deng, Anmei; Chen, Jie; Wang, Guiying; Zhu, Songcheng; Kang, Jiuhong

    2013-01-01

    The lysine acetyltransferases play crucial but complex roles in cancer development. GCN5 is a lysine acetyltransferase that generally regulates gene expression, but its role in cancer development remains largely unknown. In this study, we report that GCN5 is highly expressed in non-small cell lung cancer tissues and that its expression correlates with tumor size. We found that the expression of GCN5 promotes cell growth and the G1/S phase transition in multiple lung cancer cell lines. Further study revealed that GCN5 regulates the expression of E2F1, cyclin D1, and cyclin E1. Our reporter assays indicated that the expression of GCN5 enhances the activities of the E2F1, cyclin D1, and cyclin E1 promoters. ChIP experiments suggested that GCN5 binds directly to these promoters and increases the extent of histone acetylation within these regions. Mechanistic studies suggested that GCN5 interacts with E2F1 and is recruited by E2F1 to the E2F1, cyclin D1, and cyclin E1 promoters. The function of GCN5 in lung cancer cells is abrogated by the knockdown of E2F1. Finally, we confirmed that GCN5 regulates the expression of E2F1, cyclin D1, and cyclin E1 and potentiates lung cancer cell growth in a mouse tumor model. Taken together, our results demonstrate that GCN5 specifically potentiates lung cancer growth by directly promoting the expression of E2F1, cyclin D1, and cyclin E1 in an E2F1-dependent manner. Our study identifies a specific and novel function of GCN5 in lung cancer development and suggests that the GCN5-E2F1 interaction represents a potential target for lung cancer treatment. PMID:23543735

  16. 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

  17. GCN5 Potentiates Glioma Proliferation and Invasion via STAT3 and AKT Signaling Pathways

    PubMed Central

    Liu, Kun; Zhang, Qing; Lan, Haitao; Wang, Liping; Mou, Pengfei; Shao, Wei; Liu, Dan; Yang, Wensheng; Lin, Zhen; Lin, Qingyuan; Ji, Tianhai

    2015-01-01

    The general control of nucleotide synthesis 5 (GCN5), which is one kind of lysine acetyltransferases, regulates a number of cellular processes, such as cell proliferation, differentiation, cell cycle and DNA damage repair. However, its biological role in human glioma development remains elusive. In the present study, we firstly reported that GCN5 was frequently overexpressed in human glioma tissues and GCN5 was positively correlated with proliferation of cell nuclear antigen PCNA and matrix metallopeptidase MMP9. Meanwhile, down-regulation of GCN5 by siRNA interfering inhibited glioma cell proliferation and invasion. In addition, GCN5 knockdown reduced expression of p-STAT3, p-AKT, PCNA and MMP9 and increased the expression of p21 in glioma cells. In conclusion, GCN5 exhibited critical roles in glioma development by regulating cell proliferation and invasion, which suggested that GCN5 might be a potential molecular target for glioma treatment. PMID:26378521

  18. 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

  19. The Histone Acetyltransferase Gcn5 Regulates ncRNA-ICR1 and FLO11 Expression during Pseudohyphal Development in Saccharomyces cerevisiae

    PubMed Central

    Wang, Long-Chi; Montalvo-Munoz, Fernando; Tsai, Yuan-Chan; Liang, Chung-Yi; Chang, Chun-Chuan; Lo, Wan-Sheng

    2015-01-01

    Filamentous growth is one of the key features of pathogenic fungi during the early infectious phase. The pseudohyphal development of yeast Saccharomyces cerevisiae shares similar characteristics with hyphae elongation in pathogenic fungi. The expression of FLO11 is essential for adhesive growth and filament formation in yeast and is governed by a multilayered transcriptional network. Here we discovered a role for the histone acetyltransferase general control nonderepressible 5 (Gcn5) in regulating FLO11-mediated pseudohyphal growth. The expression patterns of FLO11 were distinct in haploid and diploid yeast under amino acid starvation induced by 3-amino-1,2,4-triazole (3AT). In diploids, FLO11 expression was substantially induced at a very early stage of pseudohyphal development and decreased quickly, but in haploids, it was gradually induced. Furthermore, the transcription factor Gcn4 was recruited to the Sfl1-Flo8 toggle sites at the FLO11 promoter under 3AT treatment. Moreover, the histone acetylase activity of Gcn5 was required for FLO11 induction. Finally, Gcn5 functioned as a negative regulator of the noncoding RNA ICR1, which is known to suppress FLO11 expression. Gcn5 plays an important role in the regulatory network of FLO11 expression via Gcn4 by downregulating ICR1 expression, which derepresses FLO11 for promoting pseudohyphal development. PMID:25922832

  20. Snf1p-dependent Spt-Ada-Gcn5-acetyltransferase (SAGA) recruitment and chromatin remodeling activities on the HXT2 and HXT4 promoters.

    PubMed

    van Oevelen, Chris J C; van Teeffelen, Hetty A A M; van Werven, Folkert J; Timmers, H Th Marc

    2006-02-17

    We previously showed that the Spt-Ada-Gcn5-acetyltransferase (SAGA) complex is recruited to the activated HXT2 and HXT4 genes and plays a role in the association of TBP-associated factors. Using the HXT2 and HXT4 genes, we now present evidence for a functional link between Snf1p-dependent activation, recruitment of the SAGA complex, histone H3 removal, and H3 acetylation. Recruitment of the SAGA complex is dependent on the release of Ssn6p-Tup1p repression by Snf1p. In addition, we found that the Gcn5p subunit of the SAGA complex preferentially acetylates histone H3K18 on the HXT2 and HXT4 promoters and that Gcn5p activity is required for removal of histone H3 from the HXT4 promoter TATA region. In contrast, histone H3 removal from the HXT2 promoter does not require Gcn5p. In conclusion, although similar protein complexes are involved, induction of HXT2 and HXT4 displays important mechanistic differences.

  1. 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

  2. TRRAP and GCN5 are used by c-Myc to activate RNA polymerase III transcription.

    PubMed

    Kenneth, Niall S; Ramsbottom, Ben A; Gomez-Roman, Natividad; Marshall, Lynne; Cole, Philip A; White, Robert J

    2007-09-18

    Activation of RNA polymerase (pol) II transcription by c-Myc generally involves recruitment of histone acetyltransferases and acetylation of histones H3 and H4. Here, we describe the mechanism used by c-Myc to activate pol III transcription of tRNA and 5S rRNA genes. Within 2 h of its induction, c-Myc appears at these genes along with the histone acetyltransferase GCN5 and the cofactor TRRAP. At the same time, occupancy of the pol III-specific factor TFIIIB increases and histone H3 becomes hyperacetylated, but increased histone H4 acetylation is not detected at these genes. The rapid acetylation of histone H3 and promoter assembly of TFIIIB, c-Myc, GCN5, and TRRAP are followed by recruitment of pol III and transcriptional induction. The selective acetylation of histone H3 distinguishes pol III activation by c-Myc from mechanisms observed in other systems.

  3. The oncoprotein HBXIP promotes migration of breast cancer cells via GCN5-mediated microtubule acetylation.

    PubMed

    Li, Leilei; Liu, Bowen; Zhang, Xiaodong; Ye, Lihong

    2015-03-13

    We have documented that the oncoprotein hepatitis B X-interacting protein (HBXIP) is able to promote migration of breast cancer cells. A subset of acetylated microtubules that accumulates in the cell leading edge is necessary for cell polarization and directional migration. In this study, we explored the hypothesis that HBXIP contributes to migration of breast cancer cells by supporting microtubule acetylation in breast cancer cells. We found that HBXIP could induce acetylated microtubules accumulating into the leading protrusion in wound-induced directional migration in breast cancer cells by immunofluorescence staining analysis. Interestingly, HBXIP was able to increase the acetylation of α-tubulin in the cells by immunofluorescence staining and Western blot analysis. Furthermore, we observed that acetyltransferase GCN5 was involved in the event that HBXIP induced increase of acetylated microtubules and their expansion in protrusions in breast cancer cells by Western blot analysis and immunofluorescence staining. Moreover, GCN5 was required for the HBXIP-enhanced migration of breast cancer cells by wound healing assay. Thus, we conclude that HBXIP promotes the migration of breast cancer cells through modulating microtubule acetylation mediated by GCN5. Therapeutically, HBXIP may serve as a novel target in breast cancer.

  4. DNA binding by Sgf11 protein affects histone H2B deubiquitination by Spt-Ada-Gcn5-acetyltransferase (SAGA).

    PubMed

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

    2014-03-28

    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.

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

    PubMed Central

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

    2016-01-01

    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

  6. 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.

  7. The Essential Cofactor TRRAP Recruits the Histone Acetyltransferase hGCN5 to c-Myc

    PubMed Central

    McMahon, Steven B.; Wood, Marcelo A.; Cole, Michael D.

    2000-01-01

    The c-Myc protein functions as a transcription factor to facilitate oncogenic transformation; however, the biochemical and genetic pathways leading to transformation remain undefined. We demonstrate here that the recently described c-Myc cofactor TRRAP recruits histone acetylase activity, which is catalyzed by the human GCN5 protein. Since c-Myc function is inhibited by recruitment of histone deacetylase activity through Mad family proteins, these opposing biochemical activities are likely to be responsible for the antagonistic biological effects of c-Myc and Mad on target genes and ultimately on cellular transformation. PMID:10611234

  8. Mutagenesis of tGCN5 core region reveals two critical surface residues F90 and R140

    SciTech Connect

    Mehta, Kinjal Rajesh; Chan, Yan M.; Lee, Man X.; Yang, Ching Yao; Voloshchuk, Natalya; Montclare, Jin Kim

    2010-09-24

    Research highlights: {yields} Mutagenesis of the tGCN5 core region reveals two residues important for function. {yields} Developed a fluorescent lysate-based activity assay to assess mutants. {yields} Surface-exposed residues F90 and R140 of tGCN5 are critical for H3 acetylation. -- Abstract: Tetrahymena General Control Non-Derepressor 5 (tGCN5) is a critical regulator of gene transcription via acetylation of histones. Since the acetylation ability has been attributed to the 'core region', we perform mutagenesis of residues within the tGCN5 'core region' in order to identify those critical for function and stability. Residues that do not participate in catalysis are identified, mutated and characterized for activity, structure and thermodynamic stability. Variants I107V, Q114L, A121T and A130S maintain the acetylation function relative to wild-type tGCN5, while variants F90Y, F112R and R140H completely abolish function. Of the three non-functional variants, since F112 is mutated into a non-homologous charged residue, a loss in function is expected. However, the remaining two variants are mutated into homologous residues, suggesting that F90 and R140 are critical for the activity of tGCN5. While mutation to homologous residue maintains acetylation of histone H3 for the majority of the variants, the two surface-exposed residues, F90 and R140, appear to be essential for tGCN5 function, structure or stability.

  9. The impact of a 48-h fast on SIRT1 and GCN5 in human skeletal muscle.

    PubMed

    Edgett, Brittany A; Scribbans, Trisha D; Raleigh, James P; Matusiak, Jennifer B L; Boonstra, Kristen; Simpson, Craig A; Perry, Christopher G R; Quadrilatero, Joe; Gurd, Brendon J

    2016-09-01

    The present study examined the impact of a 48 h fast on the expression and activation status of SIRT1 and GCN5, the relationship between SIRT1/GCN5 and the gene expression of PGC-1α, and the PGC-1α target PDK4 in the skeletal muscle of 10 lean healthy men (age, 22.0 ± 1.5 years; peak oxygen uptake, 47.2 ± 6.7 mL/(min·kg)). Muscle biopsies and blood samples were collected 1 h postprandial (Fed) and following 48 h of fasting (Fasted). Plasma insulin (Fed, 80.8 ± 47.9 pmol/L; Fasted, not detected) and glucose (Fed, 4.36 ± 0.86; Fasted, 3.74 ± 0.25 mmol/L, p = 0.08) decreased, confirming participant adherence to fasting. Gene expression of PGC-1α decreased (p < 0.05, -24%), while SIRT1 and PDK4 increased (p < 0.05, +11% and +1023%, respectively), and GCN5 remained unchanged. No changes were observed for whole-muscle protein expression of SIRT1, GCN5, PGC-1α, or COX IV. Phosphorylation of SIRT1, AMPKα, ACC, p38 MAPK, and PKA substrates as well as nuclear acetylation status was also unaltered. Additionally, nuclear SIRT1 activity, GCN5, and PGC-1α content remained unchanged. Preliminary findings derived from regression analysis demonstrate that changes in nuclear GCN5 and SIRT1 activity/phosphorylation may contribute to the control of PGC-1α, but not PDK4, messenger RNA expression following fasting. Collectively, and in contrast with previous animal studies, our data are inconsistent with the altered activation status of SIRT1 and GCN5 in response to 48 h of fasting in human skeletal muscle. PMID:27525514

  10. 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.

  11. Protein kinase Cθ gene expression is oppositely regulated by GCN5 and EBF1 in immature B cells.

    PubMed

    Kikuchi, Hidehiko; Nakayama, Masami; Kuribayashi, Futoshi; Imajoh-Ohmi, Shinobu; Nishitoh, Hideki; Takami, Yasunari; Nakayama, Tatsuo

    2014-05-01

    In this study, we revealed that GCN5 and early B cell factor 1 (EBF1) participate in regulation of protein kinase Cθ (PKCθ) gene expression in an opposite manner in immature B cells. GCN5-deficiency in DT40 caused drastic down-regulation of transcription of PKCθ. In contrast, EBF1-deficiency brought about remarkable up-regulation of that of PKCθ, and re-expression of EBF1 dramatically suppressed transcription of PKCθ. Chromatin immunoprecipitation assay revealed that GCN5 binds to the 5'-flanking region of the chicken PKCθ gene and acetylates histone H3, and EBF1 binds to the 5'-flanking region of the gene surrounding putative EBF1 binding motifs.

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

    PubMed

    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.

  13. 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

  14. 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.

  15. The Spt-Ada-Gcn5 Acetyltransferase (SAGA) complex in Aspergillus nidulans.

    PubMed

    Georgakopoulos, Paraskevi; Lockington, Robin A; Kelly, Joan M

    2013-01-01

    A mutation screen in Aspergillus nidulans uncovered mutations in the acdX gene that led to altered repression by acetate, but not by glucose. AcdX of A. nidulans is highly conserved with Spt8p of Saccharomyces cerevisiae, and since Spt8p is a component of the Spt-Ada-Gcn5 Acetyltransferase (SAGA) complex, the SAGA complex may have a role in acetate repression in A. nidulans. We used a bioinformatic approach to identify genes encoding most members of the SAGA complex in A. nidulans, and a proteomic analysis to confirm that most protein components identified indeed exist as a complex in A. nidulans. No apparent compositional differences were detected in mycelia cultured in acetate compared to glucose medium. The methods used revealed apparent differences between Yeast and A. nidulans in the deubiquitination (DUB) module of the complex, which in S. cerevisiae consists of Sgf11p, Sus1p, and Ubp8p. Although a convincing homologue of S. cerevisiae Ubp8p was identified in the A. nidulans genome, there were no apparent homologues for Sus1p and Sgf11p. In addition, when the SAGA complex was purified from A. nidulans, members of the DUB module were not co-purified with the complex, indicating that functional homologues of Sus1p and Sgf11p were not part of the complex. Thus, deubiquitination of H2B-Ub in stress conditions is likely to be regulated differently in A. nidulans compared to S. cerevisiae.

  16. 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

  17. 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

  18. 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.

  19. Analysis of the regulation of the Ustilago maydis proteome by dimorphism, pH or MAPK and GCN5 genes.

    PubMed

    Martínez-Salgado, José L; León-Ramírez, Claudia G; Pacheco, Alberto Barrera; Ruiz-Herrera, José; de la Rosa, Ana P Barba

    2013-02-21

    Ustilago maydis is a dimorphic corn pathogenic basidiomycota whose haploid cells grow in yeast form at pH7, while at pH3 they grow in the mycelial form. Two-dimensional gel electrophoresis (2-DE) coupled with LC-ESI/MS-MS was used to analyze the differential accumulation of proteins in yeast against mycelial morphologies. 2-DE maps were obtained in the pH range of 5-8 and 404 total protein spots were separated. From these, 43 were differentially accumulated when comparing strains FB2wt, constitutive yeast CL211, and constitutive mycelial GP25 growing at pH7 against pH3. Differentially accumulated proteins in response to pH are related with defense against reactive oxygen species or toxic compounds. Up-accumulation of CipC and down-accumulation of Hmp1 were specifically related with mycelial growth. Changes in proteins that were affected by mutation in the gene encoding the adaptor of a MAPK pathway (CL211 strain) were UM521* and transcription factors Btf3, Sol1 and Sti1. Mutation of GCN5 (GP25 strain) affected the accumulation of Rps19-ribosomal protein, Mge1-heath shock protein, and Lpd1-dihydrolipoamide dehydrogenase. Our results complement the information about the genes and proteins related with the dimorphic transition in U. maydis and changes in proteins affected by mutations in a MAPK pathway and GCN5 gene.

  20. The histone acetyltransferase GcnE (GCN5) plays a central role in the regulation of Aspergillus asexual development.

    PubMed

    Cánovas, David; Marcos, Ana T; Gacek, Agnieszka; Ramos, María S; Gutiérrez, Gabriel; Reyes-Domínguez, Yazmid; Strauss, Joseph

    2014-08-01

    Acetylation of histones is a key regulatory mechanism of gene expression in eukaryotes. GcnE is an acetyltransferase of Aspergillus nidulans involved in the acetylation of histone H3 at lysine 9 and lysine 14. Previous works have demonstrated that deletion of gcnE results in defects in primary and secondary metabolism. Here we unveil the role of GcnE in development and show that a ∆gcnE mutant strain has minor growth defects but is impaired in normal conidiophore development. No signs of conidiation were found after 3 days of incubation, and immature and aberrant conidiophores were found after 1 week of incubation. Centroid linkage clustering and principal component (PC) analysis of transcriptomic data suggest that GcnE occupies a central position in Aspergillus developmental regulation and that it is essential for inducing conidiation genes. GcnE function was found to be required for the acetylation of histone H3K9/K14 at the promoter of the master regulator of conidiation, brlA, as well as at the promoters of the upstream developmental regulators of conidiation flbA, flbB, flbC, and flbD (fluffy genes). However, analysis of the gene expression of brlA and the fluffy genes revealed that the lack of conidiation originated in a complete absence of brlA expression in the ∆gcnE strain. Ectopic induction of brlA from a heterologous alcA promoter did not remediate the conidiation defects in the ∆gcnE strain, suggesting that additional GcnE-mediated mechanisms must operate. Therefore, we conclude that GcnE is the only nonessential histone modifier with a strong role in fungal development found so far.

  1. Two Arabidopsis orthologs of the transcriptional coactivator ADA2 have distinct biological functions.

    PubMed

    Hark, Amy T; Vlachonasios, Konstantinos E; Pavangadkar, Kanchan A; Rao, Sumana; Gordon, Hillary; Adamakis, Ioannis-Dimosthenis; Kaldis, Athanasios; Thomashow, Michael F; Triezenberg, Steven J

    2009-02-01

    Histone acetylation is an example of covalent modification of chromatin structure that has the potential to regulate gene expression. Gcn5 is a prototypical histone acetyltransferase that associates with the transcriptional coactivator Ada2. In Arabidopsis, two genes encode proteins that resemble yeast ADA2 and share approximately 45% amino acid sequence identity. We previously reported that plants harboring a T-DNA insertion in the ADA2b gene display a dwarf phenotype with developmental defects in several organs. Here we describe T-DNA insertion alleles in the ADA2a gene, which result in no dramatic growth or developmental phenotype. Both ADA2a and ADA2b are expressed in a variety of plant tissues; moreover, expression of ADA2a from a constitutive promoter fails to complement the ada2b-1 mutant phenotype, consistent with the hypothesis that the two proteins have distinct biochemical roles. To further probe the cellular roles of ADA2a and ADA2b, we studied the response of the transcriptional coactivator mutants to abiotic stress. Although ada2b seedlings display hypersensitivity to salt and abscisic acid and altered responses to low temperature stress, the responses of ada2a seedlings to abiotic stress generally parallel those of wildtype plants. Intriguingly, ada2a;ada2b double mutant plants display an intermediate, gcn5-like phenotype, suggesting that ADA2a and ADA2b each work independently with GCN5 to affect genome function in Arabidopsis.

  2. 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

  3. The SAGA continues: expanding the cellular role of a transcriptional co-activator complex

    PubMed Central

    Baker, SP; Grant, PA

    2009-01-01

    Throughout the last decade, great advances have been made in our understanding of how DNA-templated cellular processes occur in the native chromatin environment. Proteins that regulate transcription, replication, DNA repair, mitosis and other processes must be targeted to specific regions of the genome and granted access to DNA, which is normally tightly packaged in the higher-order chromatin structure of eukaryotic nuclei. Massive multiprotein complexes have been discovered, which facilitate access to DNA and recruitment of downstream effectors through three distinct mechanisms: chemical modification of histone amino-acid residues, ATP-dependent chromatin remodeling and histone exchange. The yeast Spt-Ada-Gcn5-Acetyl transferase (SAGA) transcriptional co-activator complex regulates numerous cellular processes through coordination of multiple histone post-translational modifications. SAGA is known to generate and interact with a number of histone modifications, including acetylation, methylation, ubiquitylation and phosphorylation. Although best characterized for its role in regulating transcriptional activation, SAGA is also required for optimal transcription elongation, mRNA export and perhaps nucleotide excision repair. Here, we discuss findings from recent years that have elucidated the function of this 1.8-MDa complex in multiple cellular processes, and how misregulation of the homologous complexes in humans may ultimately play a role in development of disease. PMID:17694076

  4. 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.

  5. N-acetylglucosamine sensing by a GCN5-related N-acetyltransferase induces transcription via chromatin histone acetylation in fungi

    PubMed Central

    Su, Chang; Lu, Yang; Liu, Haoping

    2016-01-01

    N-acetylglucosamine (GlcNAc) exists ubiquitously as a component of the surface on a wide range of cells, from bacteria to humans. Many fungi are able to utilize environmental GlcNAc to support growth and induce cellular development, a property important for their survival in various host niches. However, how the GlcNAc signal is sensed and subsequently transduced is largely unknown. Here, we identify a gene that is essential for GlcNAc signalling (NGS1) in Candida albicans, a commensal and pathogenic yeast of humans. Ngs1 can bind GlcNAc through the N-terminal β-N-acetylglucosaminidase homology domain. This binding activates N-acetyltransferase activity in the C-terminal GCN5-related N-acetyltransferase domain, which is required for GlcNAc-induced promoter histone acetylation and transcription. Ngs1 is targeted to the promoters of GlcNAc-inducible genes constitutively by the transcription factor Rep1. Ngs1 is conserved in diverse fungi that have GlcNAc catabolic genes. Thus, fungi use Ngs1 as a GlcNAc-sensor and transducer for GlcNAc-induced transcription. PMID:27694804

  6. SWI/SNF recruitment to a DNA double-strand break by the NuA4 and Gcn5 histone acetyltransferases.

    PubMed

    Bennett, Gwendolyn; Peterson, Craig L

    2015-06-01

    The DNA damage response to double-strand breaks (DSBs) is critical for cellular viability. Recent work has shown that a host of chromatin regulators are recruited to a DSB, and that they are important for the DNA damage response. However, the functional relationships between different chromatin regulators at DSBs remain unclear. Here we describe a conserved functional interaction among the chromatin remodeling enzyme, SWI/SNF, the NuA4 and Gcn5 histone acetyltransferases, and phosphorylation of histone H2A.X (γH2AX). Specifically, we find that the NuA4 and Gcn5 enzymes are both required for the robust recruitment of SWI/SNF to a DSB, which in turn promotes the phosphorylation of H2A.X.

  7. Structural, Functional, and Inhibition Studies of a Gcn5-related N-Acetyltransferase (GNAT) Superfamily Protein PA4794

    PubMed Central

    Majorek, Karolina A.; Kuhn, Misty L.; Chruszcz, Maksymilian; Anderson, Wayne F.; Minor, Wladek

    2013-01-01

    The Gcn5-related N-acetyltransferase (GNAT) superfamily is a large group of evolutionarily related acetyltransferases, with multiple paralogs in organisms from all kingdoms of life. The functionally characterized GNATs have been shown to catalyze the transfer of an acetyl group from acetyl-coenzyme A (Ac-CoA) to the amine of a wide range of substrates, including small molecules and proteins. GNATs are prevalent and implicated in a myriad of aspects of eukaryotic and prokaryotic physiology, but functions of many GNATs remain unknown. In this work, we used a multi-pronged approach of x-ray crystallography and biochemical characterization to elucidate the sequence-structure-function relationship of the GNAT superfamily member PA4794 from Pseudomonas aeruginosa. We determined that PA4794 acetylates the Nϵ amine of a C-terminal lysine residue of a peptide, suggesting it is a protein acetyltransferase specific for a C-terminal lysine of a substrate protein or proteins. Furthermore, we identified a number of molecules, including cephalosporin antibiotics, which are inhibitors of PA4794 and bind in its substrate-binding site. Often, these molecules mimic the conformation of the acetylated peptide product. We have determined structures of PA4794 in the apo-form, in complexes with Ac-CoA, CoA, several antibiotics and other small molecules, and a ternary complex with the products of the reaction: CoA and acetylated peptide. Also, we analyzed PA4794 mutants to identify residues important for substrate binding and catalysis. PMID:24003232

  8. Human STAGA complex is a chromatin-acetylating transcription coactivator that interacts with pre-mRNA splicing and DNA damage-binding factors in vivo.

    PubMed

    Martinez, E; Palhan, V B; Tjernberg, A; Lymar, E S; Gamper, A M; Kundu, T K; Chait, B T; Roeder, R G

    2001-10-01

    GCN5 is a histone acetyltransferase (HAT) originally identified in Saccharomyces cerevisiae and required for transcription of specific genes within chromatin as part of the SAGA (SPT-ADA-GCN5 acetylase) coactivator complex. Mammalian cells have two distinct GCN5 homologs (PCAF and GCN5L) that have been found in three different SAGA-like complexes (PCAF complex, TFTC [TATA-binding-protein-free TAF(II)-containing complex], and STAGA [SPT3-TAF(II)31-GCN5L acetylase]). The composition and roles of these mammalian HAT complexes are still poorly characterized. Here, we present the purification and characterization of the human STAGA complex. We show that STAGA contains homologs of most yeast SAGA components, including two novel human proteins with histone-like folds and sequence relationships to yeast SPT7 and ADA1. Furthermore, we demonstrate that STAGA has acetyl coenzyme A-dependent transcriptional coactivator functions from a chromatin-assembled template in vitro and associates in HeLa cells with spliceosome-associated protein 130 (SAP130) and DDB1, two structurally related proteins. SAP130 is a component of the splicing factor SF3b that associates with U2 snRNP and is recruited to prespliceosomal complexes. DDB1 (p127) is a UV-damaged-DNA-binding protein that is involved, as part of a complex with DDB2 (p48), in nucleotide excision repair and the hereditary disease xeroderma pigmentosum. Our results thus suggest cellular roles of STAGA in chromatin modification, transcription, and transcription-coupled processes through direct physical interactions with sequence-specific transcription activators and with components of the splicing and DNA repair machineries. PMID:11564863

  9. 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.

  10. 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

  11. The mRNA export factor Sus1 is involved in Spt/Ada/Gcn5 acetyltransferase-mediated H2B deubiquitinylation through its interaction with Ubp8 and Sgf11.

    PubMed

    Köhler, Alwin; Pascual-García, Pau; Llopis, Ana; Zapater, Meritxell; Posas, Francesc; Hurt, Ed; Rodríguez-Navarro, Susana

    2006-10-01

    Sus1 acts in nuclear mRNA export via its association with the nuclear pore-associated Sac3-Thp1-Cdc31 complex. In addition, Sus1 plays a role in transcription through its interaction with the Spt/Ada/Gcn5 acetyltransferase (SAGA) complex. Here, we have analyzed function and interaction of Sus1 within the SAGA complex. We demonstrate that Sus1 is involved in the SAGA-dependent histone H2B deubiquitinylation and maintenance of normal H3 methylation levels. By deletion analyses, we show that binding of Sus1 to SAGA depends on the deubiquitinylating enzyme Ubp8 and Sgf11. Moreover, a stable subcomplex between Sus1, Sgf11, and Ubp8 could be dissociated from SAGA under high salt conditions. In vivo recruitment of Sus1 to the activated GAL1 promoter depends on Ubp8 and vice versa. In addition, histones coenrich during SAGA purification in a Sus1-Sgf11-Ubp8-dependent way. Interestingly, sgf11 deletion enhances the mRNA export defect observed in sus1delta cells. Thus, the Sus1-Sgf11-Ubp8 module could work at the junction between SAGA-dependent transcription and nuclear mRNA export.

  12. The nucleosome remodeling complex, Snf/Swi, is required for the maintenance of transcription in vivo and is partially redundant with the histone acetyltransferase, Gcn5.

    PubMed Central

    Sudarsanam, P; Cao, Y; Wu, L; Laurent, B C; Winston, F

    1999-01-01

    Snf/Swi, a nucleosome remodeling complex, is important for overcoming nucleosome-mediated repression of transcription in Saccharomyces cerevisiae. We have addressed the mechanism by which Snf/Swi controls transcription in vivo of an Snf/Swi-dependent promoter, that of the SUC2 gene. By single-cell analysis, our results show that Snf/Swi is required for activated levels of SUC2 expression in every cell of a population. In addition, Snf/Swi is required for maintenance of SUC2 transcription, suggesting that continuous chromatin remodeling is necessary to maintain an active transcriptional state. Finally, Snf/Swi and Gcn5, a histone acetyltransferase, have partially redundant roles in the control of SUC2 transcription, suggesting a functional overlap between two different mechanisms believed to overcome repression by nucleosomes, nucleosome remodeling and histone acetylation. PMID:10357821

  13. Gene induction in response to unfolded protein in the endoplasmic reticulum is mediated through Ire1p kinase interaction with a transcriptional coactivator complex containing Ada5p

    PubMed Central

    Welihinda, Ajith A.; Tirasophon, Witoon; Green, Sarah R.; Kaufman, Randal J.

    1997-01-01

    In eukaryotic cells, accumulation of unfolded protein in the endoplasmic reticulum induces transcription of a family of genes encoding endoplasmic reticulum protein chaperones through a conserved unfolded protein response element. In Saccharomyces cerevisiae, activation of a transmembrane receptor kinase, Ire1p (Ern1p), initiates signaling, although the mediators immediately downstream of Ire1 kinase are unknown. Here we demonstrate interaction of Ire1p with the transcriptional coactivator, Gcn5p (for general control nonrepressed; also known as Ada4p). Gcn5p associates with other Ada (for alteration/deficiency in activation) gene products in a heteromeric complex and has histone acetyltransferase activity. We show that the Gcn5/Ada complex is selectively required for the unfolded protein response but not for the heat shock response. A novel mechanism is proposed in which activation of a receptor kinase recruits a transcription coactivator complex to a specific chromosomal locus to mediate localized histone acetylation, thus making specific gene sequences accessible for transcription. PMID:9113982

  14. Jejunal induction of SI and SGLT1 genes in rats by high-starch/low-fat diet is associated with histone acetylation and binding of GCN5 on the genes.

    PubMed

    Inoue, Seiya; Mochizuki, Kazuki; Goda, Toshinao

    2011-01-01

    The intestinal expression of genes involved in carbohydrate digestion and absorption, such as sucrase-isomaltase (SI) and sodium-dependent glucose cotransporter (SGLT1), is higher in rodents fed a high-starch/low-fat (HS) diet than in those fed a low-starch/high-fat (LS) diet. In the present study, we investigated whether the HS diet-induced induction of SI and SGLT1 in the rat jejunum is coordinately regulated by nuclear transcription factors, histone acetylation, or histone acetyltransferases. HS diet intake induced jejunal expression of a histone acetyltransferase, general control of amino acid synthesis (GCN5), concurrently with the SI and SGLT1 genes; however, gene expression of nuclear transcription factors such as hepatocyte nuclear factor-1, caudal type homeobox-2, and GATA-binding protein-4 was unaffected by the HS diet. Acetylation of histones H3/H4 and binding of acetyltransferase GCN5 on the promoter/enhancer and transcribed regions of SI and SGLT1 genes were significantly higher in HS diet-fed rats than in LS diet-fed rats, but transcription factor binding was not affected by the HS diet. Our results suggest that the concomitant induction of SI and SGLT1 genes in the jejunum by the HS diet is closely associated with the binding of GCN5 and acetylation of histones H3/H4 on these genes.

  15. 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…

  16. A Nonnatural Transcriptional Coactivator

    NASA Astrophysics Data System (ADS)

    Nyanguile, Origene; Uesugi, Motonari; Austin, David J.; Verdine, Gregory L.

    1997-12-01

    In eukaryotes, sequence-specific DNA-binding proteins activate gene expression by recruiting the transcriptional apparatus and chromatin remodeling proteins to the promoter through protein-protein contacts. In many instances, the connection between DNA-binding proteins and the transcriptional apparatus is established through the intermediacy of adapter proteins known as coactivators. Here we describe synthetic molecules with low molecular weight that act as transcriptional coactivators. We demonstrate that a completely nonnatural activation domain in one such molecule is capable of stimulating transcription in vitro and in vivo. The present strategy provides a means of gaining external control over gene activation through intervention using small molecules.

  17. 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.

  18. TFIID and Spt-Ada-Gcn5-Acetyltransferase Functions Probed by Genome-wide Synthetic Genetic Array Analysis Using a Saccharomyces cerevisiae taf9-ts Allele

    PubMed Central

    Milgrom, Elena; West, Robert W.; Gao, Chen; Shen, W.-C. Winston

    2005-01-01

    TAF9 is a TATA-binding protein associated factor (TAF) conserved from yeast to humans and shared by two transcription coactivator complexes, TFIID and SAGA. The essentiality of the TAFs has made it difficult to ascertain their roles in TFIID and SAGA function. Here we performed a genomic synthetic genetic array analysis using a temperature-sensitive allele of TAF9 as a query. Results from this experiment showed that TAF9 interacts genetically with: (1) genes for multiple transcription factor complexes predominantly involving Mediator, chromatin modification/remodeling complexes, and regulators of transcription elongation; (2) virtually all nonessential genes encoding subunits of the SWR-C chromatin-remodeling complex and both TAF9 and SWR-C required for expressing the essential housekeeping gene RPS5; and (3) key genes for cell cycle control at the G1/S transition, as well as genes involved in cell polarity, cell integrity, and protein synthesis, suggesting a link between TAF9 function and cell growth control. We also showed that disruption of SAGA by deletion of SPT20 alters histone-DNA contacts and phosphorylated forms of RNA polymerase II at coding sequences. Our results raise the possibility of an unappreciated role for TAF9 in transcription elongation, perhaps in the context of SAGA, and provide further support for TAF9 involvement in cell cycle progression and growth control. PMID:16118188

  19. Structural basis for the interaction between yeast Spt-Ada-Gcn5 acetyltransferase (SAGA) complex components Sgf11 and Sus1.

    PubMed

    Ellisdon, Andrew M; Jani, Divyang; Köhler, Alwin; Hurt, Ed; Stewart, Murray

    2010-02-01

    Sus1 is a central component of the yeast gene gating machinery, the process by which actively transcribing genes such as GAL1 become associated with nuclear pore complexes. Sus1 is a component of both the SAGA transcriptional co-activator complex and the TREX-2 complex that binds to nuclear pore complexes. TREX-2 contains two Sus1 chains that have an articulated helical hairpin fold, enabling them to wrap around an extended alpha-helix in Sac3, following a helical hydrophobic stripe. In SAGA, Sus1 binds to Sgf11 and has been proposed to provide a link between SAGA and TREX-2. We present here the crystal structure of the complex between Sus1 and the N-terminal region of Sgf11 that forms an extended alpha-helix around which Sus1 wraps in a manner that shares some similarities with the Sus1-Sac3 interface in TREX-2. However, the Sus1-binding site on Sgf11 is somewhat shorter than on Sac3 and is based on a narrower hydrophobic stripe. Engineered mutants that disrupt the Sgf11-Sus1 interaction in vitro confirm the importance of the hydrophobic helical stripe in molecular recognition. Helix alpha1 of the Sus1-articulated hairpin does not bind directly to Sgf11 and adopts a wide range of conformations within and between crystal forms, consistent with the presence of a flexible hinge and also with results from previous extensive mutagenesis studies (Klöckner, C., Schneider, M., Lutz, S., Jani, D., Kressler, D., Stewart, M., Hurt, E., and Köhler, A. (2009) J. Biol. Chem. 284, 12049-12056). A single Sus1 molecule cannot bind Sgf11 and Sac3 simultaneously and this, combined with the structure of the Sus1-Sgf11 complex, indicates that Sus1 forms separate subcomplexes within SAGA and TREX-2.

  20. Coactivation of the human vitamin D receptor by the peroxisome proliferator-activated receptor gamma coactivator-1 alpha.

    PubMed

    Savkur, Rajesh S; Bramlett, Kelli S; Stayrook, Keith R; Nagpal, Sunil; Burris, Thomas P

    2005-08-01

    The vitamin D receptor (VDR) belongs to the superfamily of steroid/thyroid hormone receptors that is activated by 1alpha,25-dihydroxyvitamin D(3). Traditional targets for 1alpha,25-dihydroxyvitamin D(3) action include tissues involved in the maintenance of calcium homeostasis and bone development and remodeling. Peroxisome proliferator-activated receptor gamma coactivator-1alpha (PGC-1alpha), a transcriptional coactivator that plays a role in mitochondrial biogenesis and energy metabolism, is predominantly expressed in kidney, heart, liver, and skeletal muscle. Because VDR and PGC-1alpha display an overlapping pattern of expression, we investigated the possibility that PGC-1alpha could serve as a coactivator for VDR. Transient cotransfection assays demonstrate that PGC-1alpha augments ligand-dependent VDR transcription when either full-length VDR or Gal4 DNA binding domain-VDR-ligand binding domain chimeras were analyzed. Furthermore, mammalian two-hybrid assays, coimmunoprecipitation analyses, and biochemical coactivator recruitment assays demonstrate a ligand-dependent interaction between the two proteins both in cells and in vitro. The coactivation potential of PGC-1alpha requires an intact AF-2 domain of VDR and the LXXLL motif in PGC-1alpha. Taken together, these results indicate that PGC-1alpha serves as a coactivator for VDR.

  1. 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.

  2. 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.

  3. 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.

  4. Emerging roles of TEAD transcription factors and its coactivators in cancers.

    PubMed

    Pobbati, Ajaybabu V; Hong, Wanjin

    2013-05-01

    TEAD proteins are transcription factors that are crucial for development, but also play a role in cancers. Several developmentally and pathologically important genes are upregulated by TEADs. TEADs have a TEA domain that enables them to bind specific DNA elements and a transactivation domain that enables them to interact with coactivators. TEADs on their own are unable to activate transcription and they require the help of coactivators. Several TEAD-interacting coactivators are known and they can be classified into three groups: (1) YAP and its paralog TAZ; (2) Vgll proteins; and (3) p160s. Accordingly, these coactivators also play a role in development and cancers. Recent studies have shown that TEADs and their coactivators aid in the progression of various cancers, including the difficult to treat glioblastoma, liver and ovarian cancers. They facilitate cancer progression through expression of proliferation promoting genes such as c-myc, survivin, Axl, CTGF and Cyr61. There is also a good correlation between high TEAD or its coactivator expression and poor prognosis in various cancers. Given the fact that TEADs and their coactivators need to work together for a functional outcome, disrupting the interaction between them appears to be a viable option for cancer therapy. Structures of TEAD-coactivator complexes have been elucidated and will facilitate drug design and development.

  5. MDC1 functionally identified as an androgen receptor co-activator participates in suppression of prostate cancer

    PubMed Central

    Wang, Chunyu; Sun, Hongmiao; Zou, Renlong; Zhou, Tingting; Wang, Shengli; Sun, Shiying; Tong, Changci; Luo, Hao; Li, Yanshu; Li, Zhenhua; Wang, Enhua; Chen, Yuhua; Cao, Liu; Li, Feng; Zhao, Yue

    2015-01-01

    Mediator of DNA damage checkpoint protein 1 (MDC1) is essential for DNA damage response. However, the role of MDC1 in modulating gene transcription independently of DNA damage and the underlying mechanisms have not been fully defined. Androgen receptor (AR) is the central signaling pathway in prostate cancer (PCa) and its target genes are involved in both promotion and suppression of PCa. Here, we functionally identified MDC1 as a co-activator of AR. We demonstrate that MDC1 facilitates the association between AR and histone acetyltransferase GCN5, thereby increasing histone H3 acetylation level on cis-regulatory elements of AR target genes. MDC1 knockdown promotes PCa cells growth and migration. Moreover, depletion of MDC1 results in decreased expression of a subset of the endogenous androgen-induced target genes, including cell cycle negative regulator p21 and PCa metastasis inhibitor Vinculin, in AR positive PCa cell lines. Finally, the expression of MDC1 and p21 correlates negatively with aggressive phenotype of clinical PCa. These studies suggest that MDC1 as an epigenetic modifier regulates AR transcriptional activity and MDC1 may function as a tumor suppressor of PCa, and provide new insight into co-factor-AR-signaling pathway mechanism and a better understanding of the function of MDC1 on PCa. PMID:25934801

  6. Ligand-dependent coactivation of the human bile acid receptor FXR by the peroxisome proliferator-activated receptor gamma coactivator-1alpha.

    PubMed

    Savkur, Rajesh S; Thomas, Jeffrey S; Bramlett, Kelli S; Gao, Yunling; Michael, Laura F; Burris, Thomas P

    2005-01-01

    Peroxisome proliferator-activated receptor gamma coactivator-1alpha (PGC-1alpha) has been shown to play an important role in energy metabolism by coordinating transcriptional programs involved in mitochondrial biogenesis, adaptive thermogenesis, gluconeogenesis, and fatty acid oxidation. PGC-1alpha also plays a crucial role in cholesterol metabolism by serving as a coactivator of the liver X receptor-alpha and inducing the expression of cholesterol 7-alpha-hydroxylase. Here, we demonstrate that PGC-1alpha also functions as an effective coactivator of farnesoid X receptor (FXR), the bile acid receptor. Transient cotransfection assays demonstrate that PGC-1alpha enhances ligand-mediated FXR transcription when either full-length FXR or Gal4 DNA binding domain-FXR-ligand binding domain chimeras were analyzed. Mammalian two-hybrid analyses, glutathione S-transferase affinity chromatography and biochemical coactivator recruitment assays demonstrate ligand-dependent interaction between the two proteins both in vivo and in vitro. PGC-1alpha-mediated coactivation of FXR was highly ligand-dependent and absolutely required an intact activation function-2 (AF-2) domain of FXR and the LXXLL motif in PGC-1alpha. The integrity of the charge clamp was required, further illustrating the role of the ligand binding domain of FXR in PGC-1alpha recognition. Together, these results indicate that PGC-1alpha functions as a potent coactivator for FXR and further implicates its role in the regulation of genes that are involved in bile acid and lipid metabolism.

  7. Mechanism of CREB recognition and coactivation by the CREB-regulated transcriptional coactivator CRTC2.

    PubMed

    Luo, Qianyi; Viste, Kristin; Urday-Zaa, Janny Concha; Senthil Kumar, Ganesan; Tsai, Wen-Wei; Talai, Afsaneh; Mayo, Kelly E; Montminy, Marc; Radhakrishnan, Ishwar

    2012-12-18

    Basic leucine zipper (bZip) transcription factors regulate cellular gene expression in response to a variety of extracellular signals and nutrient cues. Although the bZip domain is widely known to play significant roles in DNA binding and dimerization, recent studies point to an additional role for this motif in the recruitment of the transcriptional apparatus. For example, the cAMP response element binding protein (CREB)-regulated transcriptional coactivator (CRTC) family of transcriptional coactivators has been proposed to promote the expression of calcium and cAMP responsive genes, by binding to the CREB bZip in response to extracellular signals. Here we show that the CREB-binding domain (CBD) of CRTC2 folds into a single isolated 28-residue helix that seems to be critical for its interaction with the CREB bZip. The interaction is of micromolar affinity on palindromic and variant half-site cAMP response elements (CREs). The CBD and CREB assemble on the CRE with 2:2:1 stoichiometry, consistent with the presence of one CRTC binding site on each CREB monomer. Indeed, the CBD helix and the solvent-exposed residues in the dimeric CREB bZip coiled-coil form an extended protein-protein interface. Because mutation of relevant bZip residues in this interface disrupts the CRTC interaction without affecting DNA binding, our results illustrate that distinct DNA binding and transactivation functions are encoded within the structural constraints of a canonical bZip domain.

  8. 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

  9. Hepatitis B virus pX interacts with HBXAP, a PHD finger protein to coactivate transcription.

    PubMed

    Shamay, Meir; Barak, Orr; Doitsh, Gilad; Ben-Dor, Israel; Shaul, Yosef

    2002-03-22

    Hepatitis B virus (HBV) gene expression is mainly regulated at the transcription initiation level. The viral X protein (pX) is a transcription coactivator/mediator targeting TFIIB for the recruitment of RNA polymerase II. Here we report a novel pX nuclear target designated HBXAP (hepatitis B virus X-associated protein). HBXAP is a novel cellular nuclear protein containing a PHD (plant homology domain) finger, a domain shared by many proteins that play roles in chromatin remodeling, transcription coactivation, and oncogenesis. pX physically interacts with HBXAP in vitro and in vivo via the HBXAP region containing the PHD finger. At the functional level HBXAP increases HBV transcription in a pX-dependent manner suggesting a role for this interaction in the virus life cycle. Interestingly, HBXAP collaborates with pX in coactivating the transcriptional activator NF-kappaB. Coactivation of NF-kappaB was also observed in tumor necrosis factor alpha-treated cells suggesting that pX-HBXAP functional collaboration localized downstream to the NF-kappaB nuclear import. Collectively our data suggest that pX recruits and potentiates a novel putative transcription coactivator to regulate NF-kappaB. The implication of pX-HBXAP interaction in the development of hepatocellular carcinoma is discussed. PMID:11788598

  10. 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

  11. 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

  12. 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.

  13. MUSCLE COACTIVATION: A GENERALIZED OR LOCALIZED MOTOR CONTROL STRATEGY?

    PubMed Central

    FREY-LAW, LAURA A.; AVIN, KEITH G.

    2014-01-01

    Introduction We examined generalized versus joint-specific influences on muscle coactivation. Methods Muscle coactivation was assessed during maximal isometric and isokinetic knee and elbow joint extension moments in 48 healthy subjects (27 men). Local (joint-specific) and generalized (person-specific) contributions were examined using a combination of statistical tests, including regression with generalized estimating equations (GEEs), exploratory factor analysis, and cluster analysis. Results GEEs produced similar significant coefficients for gender and joint; contraction type and test condition (angle or velocity) were not significant. Factor analysis indicated 2 joint-based factors, and cluster analysis indicated 2 groups of individuals, those with and without elevated coactivation at the knee and elbow. Women exhibited greater coactivation at both joints, but no consistent influences of angle or velocity were observed at either joint. Conclusion Muscle coactivation is a neuromuscular control response determined by local, joint-specific, and generalized, individual-specific influences. PMID:24037745

  14. 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

  15. An Extension of SIC Predictions to the Wiener Coactive Model.

    PubMed

    Houpt, Joseph W; Townsend, James T

    2011-06-01

    The survivor interaction contrasts (SIC) is a powerful measure for distinguishing among candidate models of human information processing. One class of models to which SIC analysis can apply are the coactive, or channel summation, models of human information processing. In general, parametric forms of coactive models assume that responses are made based on the first passage time across a fixed threshold of a sum of stochastic processes. Previous work has shown that that the SIC for a coactive model based on the sum of Poisson processes has a distinctive down-up-down form, with an early negative region that is smaller than the later positive region. In this note, we demonstrate that a coactive process based on the sum of two Wiener processes has the same SIC form.

  16. Coactivators p300 and CBP maintain the identity of mouse embryonic stem cells by mediating long-range chromatin structure.

    PubMed

    Fang, Fang; Xu, Yifeng; Chew, Kai-Khen; Chen, Xi; Ng, Huck-Hui; Matsudaira, Paul

    2014-07-01

    Master transcription factors Oct4, Sox2, and Nanog are required to maintain the pluripotency and self-renewal of embryonic stem cells (ESCs) by regulating a specific transcriptional network. A few other transcription factors have been shown to be important in ESCs by interacting with these master transcription factors; however, little is known about the transcriptional mechanisms regulated by coregulators (coactivators and corepressors). In this study, we examined the function of two highly homologous coactivators, p300 and CREB-binding protein (CBP), in ESCs. We find that these two coactivators play redundant roles in maintaining the undifferentiated state of ESCs. They are recruited by Nanog through physical interaction to Nanog binding loci, mediating the formation of long-range chromatin looping structures, which is essential to maintain ESC-specific gene expression. Further functional studies reveal that the p300/CBP binding looping fragments contain enhancer activities, suggesting that the formation of p300/CBP-mediated looping structures may recruit distal enhancers to create a concentration of factors for the transcription activation of genes that are involved in self-renewal and pluripotency. Overall, these results provide a total new insight into the transcriptional regulation mechanism of coactivators p300 and CBP in ESCs, which is important in maintaining self-renewal and pluripotency, by mediating the formation of higher order chromosome structures.

  17. 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

  18. 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

  19. 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

  20. 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.

  1. A Coactive Sign System for Children Who Are Dual-Sensory Impaired.

    ERIC Educational Resources Information Center

    Watkins, Susan; Clark, Thomas C.

    1991-01-01

    The SKI*HI Institute (Utah) has developed a system of coactive signing for children who are deaf and blind. The system includes optimized coactive signs that are functional, easy to feel, easy to relate to the referent, and easy to make. It also includes techniques for effective coactive sign use. Videotapes of lessons are described. (Author/DB)

  2. 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…

  3. Dissecting allosteric effects of activator-coactivator complexes using a covalent small molecule ligand.

    PubMed

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

    2014-08-19

    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.

  4. 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

  5. A TAF4 coactivator function for E proteins that involves enhanced TFIID binding

    PubMed Central

    Chen, Wei-Yi; Zhang, Jinsong; Geng, Huimin; Du, Zhimei; Nakadai, Tomoyoshi; Roeder, Robert G.

    2013-01-01

    The multisubunit TFIID plays a direct role in transcription initiation by binding to core promoter elements and directing preinitiation complex assembly. Although TFIID may also function as a coactivator through direct interactions with promoter-bound activators, mechanistic aspects of this poorly defined function remain unclear. Here, biochemical studies show a direct TFIID–E-protein interaction that (1) is mediated through interaction of a novel E-protein activation domain (activation domain 3 [AD3]) with the TAF homology (TAFH) domain of TAF4, (2) is critical for activation of a natural target gene by an E protein, and (3) mechanistically acts by enhancing TFIID binding to the core promoter. Complementary assays establish a gene-specific role for the TAFH domain in TFIID recruitment and activation of a large subset of genes in vivo. These results firmly establish TAF4 as a bona fide E-protein coactivator as well as a mechanism involving facilitated TFIID binding through direct interaction with an E-protein activation domain. PMID:23873942

  6. Transcriptional Coactivator and Chromatin Protein PC4 Is Involved in Hippocampal Neurogenesis and Spatial Memory Extinction.

    PubMed

    Swaminathan, Amrutha; Delage, Hélène; Chatterjee, Snehajyoti; Belgarbi-Dutron, Laurence; Cassel, Raphaelle; Martinez, Nicole; Cosquer, Brigitte; Kumari, Sujata; Mongelard, Fabien; Lannes, Béatrice; Cassel, Jean-Christophe; Boutillier, Anne-Laurence; Bouvet, Philippe; Kundu, Tapas K

    2016-09-23

    Although the elaborate combination of histone and non-histone protein complexes defines chromatin organization and hence regulates numerous nuclear processes, the role of chromatin organizing proteins remains unexplored at the organismal level. The highly abundant, multifunctional, chromatin-associated protein and transcriptional coactivator positive coactivator 4 (PC4/Sub1) is absolutely critical for life, because its absence leads to embryonic lethality. Here, we report results obtained with conditional PC4 knock-out (PC4(f/f) Nestin-Cre) mice where PC4 is knocked out specifically in the brain. Compared with the control (PC4(+/+) Nestin-Cre) mice, PC4(f/f) Nestin-Cre mice are smaller with decreased nocturnal activity but are fertile and show no motor dysfunction. Neurons in different areas of the brains of these mice show sensitivity to hypoxia/anoxia, and decreased adult neurogenesis was observed in the dentate gyrus. Interestingly, PC4(f/f) Nestin-Cre mice exhibit a severe deficit in spatial memory extinction, whereas acquisition and long term retention were unaffected. Gene expression analysis of the dorsal hippocampus of PC4(f/f) Nestin-Cre mice revealed dysregulated expression of several neural function-associated genes, and PC4 was consistently found to localize on the promoters of these genes, indicating that PC4 regulates their expression. These observations indicate that non-histone chromatin-associated proteins like PC4 play a significant role in neuronal plasticity.

  7. 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…

  8. Akt regulates basic helix-loop-helix transcription factor-coactivator complex formation and activity during neuronal differentiation.

    PubMed

    Vojtek, Anne B; Taylor, Jennifer; DeRuiter, Stacy L; Yu, Jenn-Yah; Figueroa, Claudia; Kwok, Roland P S; Turner, David L

    2003-07-01

    Neural basic helix-loop-helix (bHLH) transcription factors regulate neurogenesis in vertebrates. Signaling by peptide growth factors also plays critical roles in regulating neuronal differentiation and survival. Many peptide growth factors activate phosphatidylinositol 3-kinase (PI3K) and subsequently the Akt kinases, raising the possibility that Akt may impact bHLH protein function during neurogenesis. Here we demonstrate that reducing expression of endogenous Akt1 and Akt2 by RNA interference (RNAi) reduces neuron generation in P19 cells transfected with a neural bHLH expression vector. The reduction in neuron generation from decreased Akt expression is not solely due to decreased cell survival, since addition of the caspase inhibitor z-VAD-FMK rescues cell death associated with loss of Akt function but does not restore neuron formation. This result indicates that Akt1 and Akt2 have additional functions during neuronal differentiation that are separable from neuronal survival. We show that activated Akt1 enhances complex formation between bHLH proteins and the transcriptional coactivator p300. Activated Akt1 also significantly augments the transcriptional activity of the bHLH protein neurogenin 3 in complex with the coactivators p300 or CBP. In addition, inhibition of endogenous Akt activity by the PI3K/Akt inhibitor LY294002 abolishes transcriptional cooperativity between the bHLH proteins and p300. We propose that Akt regulates the assembly and activity of bHLH-coactivator complexes to promote neuronal differentiation.

  9. SDP1 is a peroxisome-proliferator-activated receptor gamma 2 co-activator that binds through its SCAN domain.

    PubMed Central

    Babb, Robert; Bowen, Benjamin R

    2003-01-01

    Peroxisome-proliferator-activated receptors (PPARs), members of the nuclear hormone receptor superfamily, play an important role in the regulation of lipid metabolism and energy homoeostasis. In a yeast two-hybrid experiment using the zinc-finger transcription factor ZNF202 as bait, we previously identified the SCAN-domain-containing protein SDP1. SDP1 shares a high degree of amino acid sequence identity with PGC-2, a previously identified PPAR gamma 2 co-activator from the mouse. Here we show that SDP1 and PGC-2 interact with PPAR gamma 2 through their SCAN domains, even though PPAR gamma 2 does not contain a SCAN domain. Similar to PGC-2, SDP1 enhanced PPAR gamma 2-dependent gene transcription in transiently transfected cells but did not alter the affinity of PPAR gamma 2 for agonists. Although the SCAN domain was necessary for binding to PPAR gamma 2, it was not sufficient for co-activation in cells, suggesting that other features of SDP1 are responsible for transcriptional co-activation. The ability of SDP1 to interact with two different transcription factors that regulate genes involved in lipid metabolism, ZNF202 and PPAR gamma 2, suggests that SDP1 may be an important co-regulator of such genes. PMID:12444922

  10. Language Play.

    ERIC Educational Resources Information Center

    Schwartz, Judy I.

    This paper discusses kinds and characteristics of language play, explores the relationship of such play to wider domains of language and play, and speculates on the possible contributions of language play for language mastery and cognitive development. Jump rope chants and ritual insults ("Off my case, potato face") and other expressive language…

  11. Crif1 is a novel transcriptional coactivator of STAT3.

    PubMed

    Kwon, Min-chul; Koo, Bon-Kyoung; Moon, Jin-Sook; Kim, Yoon-Young; Park, Ki Cheol; Kim, Nam-Shik; Kwon, Mi Yi; Kong, Myung-Phil; Yoon, Ki-Jun; Im, Sun-Kyoung; Ghim, Jaewang; Han, Yong-Mahn; Jang, Sung Key; Shong, Minho; Kong, Young-Yun

    2008-02-20

    Signal transducer and activator of transcription 3 (STAT3) is a transcriptional factor that performs a broad spectrum of biological functions in response to various stimuli. However, no specific coactivator that regulates the transcriptional activity of STAT3 has been identified. Here we report that CR6-interacting factor 1 (Crif1) is a specific transcriptional coactivator of STAT3, but not of STAT1 or STAT5a. Crif1 interacts with STAT3 and positively regulates its transcriptional activity. Crif1-/- embryos were lethal around embryonic day 6.5, and manifested developmental arrest accompanied with defective proliferation and massive apoptosis. The expression of STAT3 target genes was markedly reduced in a Crif1-/- blastocyst culture and in Oncostatin M-stimulated Crif1-deficient MEFs. Importantly, the key activities of constitutively active STAT3-C, such as transcription, DNA binding, and cellular transformation, were abolished in the Crif1-null MEFs, suggesting the essential role of Crif1 in the transcriptional activity of STAT3. Our results reveal that Crif1 is a novel and essential transcriptional coactivator of STAT3 that modulates its DNA binding ability, and shed light on the regulation of oncogenic STAT3.

  12. PGC-1 Coactivator Activity Is Required for Murine Erythropoiesis

    PubMed Central

    Cui, Shuaiying; Tanabe, Osamu; Lim, Kim-Chew; Xu, H. Eric; Zhou, X. Edward; Lin, Jiandie D.; Shi, Lihong; Schmidt, Lindsay; Campbell, Andrew; Shimizu, Ritsuko; Yamamoto, Masayuki

    2014-01-01

    Peroxisome proliferator-activated receptor gamma (PPARγ) coactivator 1α (PGC-1α) and PGC-1β have been shown to be intimately involved in the transcriptional regulation of cellular energy metabolism as well as other biological processes, but both coactivator proteins are expressed in many other tissues and organs in which their function is, in essence, unexplored. Here, we found that both PGC-1 proteins are abundantly expressed in maturing erythroid cells. PGC-1α and PGC-1β compound null mutant (Pgc-1c) animals express less β-like globin mRNAs throughout development; consequently, neonatal Pgc-1c mice exhibit growth retardation and profound anemia. Flow cytometry shows that the number of mature erythrocytes is markedly reduced in neonatal Pgc-1c pups, indicating that erythropoiesis is severely compromised. Furthermore, hematoxylin and eosin staining revealed necrotic cell death and cell loss in Pgc-1c livers and spleen. Chromatin immunoprecipitation studies revealed that both PGC-1α and -1β, as well as two nuclear receptors, TR2 and TR4, coordinately bind to the various globin gene promoters. In addition, PGC-1α and -1β can interact with TR4 to potentiate transcriptional activation. These data provide new insights into our understanding of globin gene regulation and raise the interesting possibility that the PGC-1 coactivators can interact with TR4 to elicit differential stage-specific effects on globin gene transcription. PMID:24662048

  13. 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

  14. 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

  15. CREB-regulated transcription coactivator 1: important roles in neurodegenerative disorders.

    PubMed

    Xue, Zhan-Cheng; Wang, Chuang; Wang, Qin-Wen; Zhang, Jun-Fang

    2015-04-25

    The cAMP-responsive element binding protein (CREB)-regulated transcription coactivator, CRTC (also known as transducer of regulated CREB, TORC), is identified as a potent modulator of cAMP response element (CRE)-driven gene transcription. The CRTC family consists of three members (CRTC1-3), among which the CRTC1 shows the highest expression in the brain. Several studies have demonstrated that the CRTC1 plays critical roles in neuronal dendritic growth, long-term synaptic plasticity, memory consolidation and reconsolidation etc., whereas dysfunction of CRTC1 is mainly involved in neurodegenerative disorders. In light of these findings, we aim to review recent research reports that indicate the CRTC1 dysfunction and its underlying mechanisms in the neurodegenerative disorders.

  16. Play Therapy

    PubMed Central

    Kool, Ritesh

    2010-01-01

    Play therapy represents a unique form of treatment that is not only geared toward young children, but is translated into a language children can comprehend and utilize—the language of play. For the referring provider or practitioner, questions may remain regarding the nature, course, and efficacy of play therapy. This article reviews the theoretical underpinnings of play therapy, some practical considerations, and finally a summary of the current state of research in regard to play therapy. The authors present the practicing psychiatrist with a road map for referring a patient to play therapy or initiating it in appropriate cases. PMID:21103141

  17. Ligand and coactivator identity determines the requirement of the charge clamp for coactivation of the peroxisome proliferator-activated receptor gamma.

    PubMed

    Wu, Yifei; Chin, William W; Wang, Yong; Burris, Thomas P

    2003-03-01

    The activation function 2 (AF-2)-dependent recruitment of coactivator is essential for gene activation by nuclear receptors. We show that the peroxisome proliferator-activated receptor gamma (PPARgamma) (NR1C3) coactivator-1 (PGC-1) requires both the intact AF-2 domain of PPARgamma and the LXXLL domain of PGC-1 for ligand-dependent and ligand-independent interaction and coactivation. Although the AF-2 domain of PPARgamma is absolutely required for PGC-1-mediated coactivation, this coactivator displayed a unique lack of requirement for the charge clamp of the ligand-binding domain of the receptor that is thought to be essential for LXXLL motif recognition. The mutation of a single serine residue adjacent to the core LXXLL motif of PGC-1 led to restoration of the typical charge clamp requirement. Thus, the unique structural features of the PGC-1 LXXLL motif appear to mediate an atypical mode of interaction with PPARgamma. Unexpectedly, we discovered that various ligands display variability in terms of their requirement for the charge clamp of PPARgamma for coactivation by PGC-1. This ligand-selective variable requirement for the charge clamp was coactivator-specific. Thus, distinct structural determinants, which may be unique for a particular ligand, are utilized by the receptor to recognize the coactivator. Our data suggest that even subtle differences in ligand structure are perceived by the receptor and translated into a unique display of the coactivator-binding surface of the ligand-binding domain, allowing for differential recognition of coactivators that may underlie distinct pharmacological profiles observed for ligands of a particular nuclear receptor.

  18. 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)

  19. 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

  20. 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.

  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. 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

  3. Playing Shakespeare.

    ERIC Educational Resources Information Center

    Bashian, Kathleen Ryniker

    1993-01-01

    Describes a yearlong project at 12 Catholic middle schools in the Diocese of Arlington, Virginia, to incorporate the plays of William Shakespeare into the curriculum. Teachers attended university lectures and directed students in performances of the plays. Concludes that Shakespeare can be understood and enjoyed by middle school students. (BCY)

  4. Why Play?

    ERIC Educational Resources Information Center

    Weininger, O.

    This paper draws together briefly theories and knowledge from research in morphology and cognitive psychology, as well as some hypothetical information from traditional psychiatry, to show the ramifications of play in children's development. Play is defined as any of a wide variety of behaviors through which an individual attempts to discover what…

  5. 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…

  6. 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

  7. 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.

  8. 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

  9. Clock and light regulation of the CREB coactivator CRTC1 in the suprachiasmatic circadian clock.

    PubMed

    Sakamoto, Kensuke; Norona, Frances E; Alzate-Correa, Diego; Scarberry, Daniel; Hoyt, Kari R; Obrietan, Karl

    2013-05-22

    The CREB/CRE transcriptional pathway has been implicated in circadian clock timing and light-evoked clock resetting. To date, much of the work on CREB in circadian physiology has focused on how changes in the phosphorylation state of CREB regulate the timing processes. However, beyond changes in phosphorylation, CREB-dependent transcription can also be regulated by the CREB coactivator CRTC (CREB-regulated transcription coactivator), also known as TORC (transducer of regulated CREB). Here we profiled both the rhythmic and light-evoked regulation of CRTC1 and CRTC2 in the murine suprachiasmatic nucleus (SCN), the locus of the master mammalian clock. Immunohistochemical analysis revealed rhythmic expression of CRTC1 in the SCN. CRTC1 expression was detected throughout the dorsoventral extent of the SCN in the middle of the subjective day, with limited expression during early night, and late night expression levels intermediate between mid-day and early night levels. In contrast to CRTC1, robust expression of CRTC2 was detected during both the subjective day and night. During early and late subjective night, a brief light pulse induced strong nuclear accumulation of CRTC1 in the SCN. In contrast with CRTC1, photic stimulation did not affect the subcellular localization of CRTC2 in the SCN. Additionally, reporter gene profiling and chromatin immunoprecipitation analysis indicated that CRTC1 was associated with CREB in the 5' regulatory region of the period1 gene, and that overexpression of CRTC1 leads to a marked upregulation in period1 transcription. Together, these data raise the prospect that CRTC1 plays a role in fundamental aspects of SCN clock timing and entrainment.

  10. Characterization of ASC-2 as an antiatherogenic transcriptional coactivator of liver X receptors in macrophages.

    PubMed

    Kim, Geun Hyang; Park, Keunhee; Yeom, Seon-Yong; Lee, Kyung Jin; Kim, Gukhan; Ko, Jesang; Rhee, Dong-Kwon; Kim, Young Hoon; Lee, Hye Kyung; Kim, Hae Won; Oh, Goo Taeg; Lee, Ki-Up; Lee, Jae W; Kim, Seung-Whan

    2009-07-01

    Activating signal cointegrator-2 (ASC-2) functions as a transcriptional coactivator of many nuclear receptors and also plays important roles in the physiology of the liver and pancreas by interacting with liver X receptors (LXRs), which antagonize the development of atherosclerosis. This study was undertaken to establish the specific function of ASC-2 in macrophages and atherogenesis. Intriguingly, ASC-2 was more highly expressed in macrophages than in the liver and pancreas. To inhibit LXR-specific activity of ASC-2, we used DN2, which contains the C-terminal LXXLL motif of ASC-2 and thereby acts as an LXR-specific, dominant-negative mutant of ASC-2. In DN2-overexpressing transgenic macrophages, cellular cholesterol content was higher and cholesterol efflux lower than in control macrophages. DN2 reduced LXR ligand-dependent increases in the levels of ABCA1, ABCG1, and apolipoprotein E (apoE) transcripts as well as the activity of luciferase reporters driven by the LXR response elements (LXREs) of ABCA1, ABCG1, and apoE genes. These inhibitory effects of DN2 were reversed by overexpression of ASC-2. Chromatin immunoprecipitation analysis demonstrated that ASC-2 was recruited to the LXREs of the ABCA1, ABCG1, and apoE genes in a ligand-dependent manner and that DN2 interfered with the recruitment of ASC-2 to these LXREs. Furthermore, low-density lipoprotein receptor (LDLR)-null mice receiving bone marrow transplantation from DN2-transgenic mice showed accelerated atherogenesis when administered a high-fat diet. Taken together, these results indicate that suppression of the LXR-specific activity of ASC-2 results in both defective cholesterol metabolism in macrophages and accelerated atherogenesis, suggesting that ASC-2 is an antiatherogenic coactivator of LXRs in macrophages.

  11. 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

  12. 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…

  13. Effects of Interdependent, Coactive, and Individualized Working Conditions on Pupils' Educational Computer Program Performance.

    ERIC Educational Resources Information Center

    Chernick, Robert S.

    1990-01-01

    Effects of social facilitation and equilibriation were examined for 80 third and fourth graders working under interdependent, coactive, or individualized conditions to complete high and low complexity computer tasks. Results indicate that interdependent and coactive conditions are not detrimental to performance but do not enhance individualized…

  14. Play & Play Grounds. A Report.

    ERIC Educational Resources Information Center

    Stone, Jeannette Galambos

    Using camera and tape recorder, a photographer and an early childhood specialist explored as a team the universe of children's outdoor play, seeking worthy and innovative ideas and stressing urban playground problems and solutions. The resulting photographs and text focus on (1) the characteristics of play, (2) the nature of playgrounds, and (3)…

  15. 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

    2015-04-10

    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.

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

    PubMed Central

    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

  17. Shadow Play

    ERIC Educational Resources Information Center

    Ward, Alan

    1974-01-01

    Discusses the use of shadows to explain such scientific phenomena as umbra and penumbra, eclipses, day and night, seasons, and length of day. Indicates that shadow plays can serve to help the students in understanding more about light. (CC)

  18. ICA model order selection of task co-activation networks

    PubMed Central

    Ray, Kimberly L.; McKay, D. Reese; Fox, Peter M.; Riedel, Michael C.; Uecker, Angela M.; Beckmann, Christian F.; Smith, Stephen M.; Fox, Peter T.; Laird, Angela R.

    2013-01-01

    Independent component analysis (ICA) has become a widely used method for extracting functional networks in the brain during rest and task. Historically, preferred ICA dimensionality has widely varied within the neuroimaging community, but typically varies between 20 and 100 components. This can be problematic when comparing results across multiple studies because of the impact ICA dimensionality has on the topology of its resultant components. Recent studies have demonstrated that ICA can be applied to peak activation coordinates archived in a large neuroimaging database (i.e., BrainMap Database) to yield whole-brain task-based co-activation networks. A strength of applying ICA to BrainMap data is that the vast amount of metadata in BrainMap can be used to quantitatively assess tasks and cognitive processes contributing to each component. In this study, we investigated the effect of model order on the distribution of functional properties across networks as a method for identifying the most informative decompositions of BrainMap-based ICA components. Our findings suggest dimensionality of 20 for low model order ICA to examine large-scale brain networks, and dimensionality of 70 to provide insight into how large-scale networks fractionate into sub-networks. We also provide a functional and organizational assessment of visual, motor, emotion, and interoceptive task co-activation networks as they fractionate from low to high model-orders. PMID:24339802

  19. The obesity-associated Fto gene is a transcriptional coactivator.

    PubMed

    Wu, Qiong; Saunders, Rudel A; Szkudlarek-Mikho, Maria; Serna, Ivana de la; Chin, Khew-Voon

    2010-10-22

    The fat mass and obesity associated, FTO, gene has been shown to be associated with obesity in human in several genome-wide association scans. In vitro studies suggest that Fto may function as a single-stranded DNA demethylase. In addition, homologous recombination-targeted knockout of Fto in mice resulted in growth retardation, loss of white adipose tissue, and increase energy metabolism and systemic sympathetic activation. Despite these intense investigations, the exact function of Fto remains unclear. We show here that Fto is a transcriptional coactivator that enhances the transactivation potential of the CCAAT/enhancer binding proteins (C/EBPs) from unmethylated as well as methylation-inhibited gene promoters. Fto also exhibits nuclease activity. We showed further that Fto enhances the binding C/EBP to unmethylated and methylated DNA. The coactivator role of FTO in modulating the transcriptional regulation of adipogenesis by C/EBPs is consistent with the temporal progressive loss of adipose tissue in the Fto-deficient mice, thus suggesting a role for Fto in the epigenetic regulation of the development and maintenance of fat tissue. How FTO reactivates transcription from methyl-repressed gene needs to be further investigated.

  20. The HIV-1 Virion-associated Protein Vpr Is a Coactivator of the Human Glucocorticoid Receptor

    PubMed Central

    Kino, Tomoshige; Gragerov, Alexander; Kopp, Jeffrey B.; Stauber, Roland H.; Pavlakis, George N.; Chrousos, George P.

    1999-01-01

    The HIV-1 virion-associated accessory protein Vpr affects both viral replication and cellular transcription, proliferation, and differentiation. We report that Vpr enhances the activity of glucocorticoids in lymphoid and muscle-derived cell lines by interacting directly with the glucocorticoid receptor and general transcription factors, acting as a coactivator. Vpr contains the signature motif LXXLL also present in cellular nuclear receptor coactivators, such as steroid receptor coactivator 1 and p300/CREB-binding protein, which mediates their interaction with the glucocorticoid and other nuclear hormone receptors. A mutant Vpr molecule with disruption of this coactivator signature motif lost its ability to influence transcription of glucocorticoid-responsive genes and became a dominant-negative inhibitor of Vpr, possibly by retaining its general transcription factor–binding activities. The glucocorticoid coactivator activity of Vpr may contribute to increased tissue glucocorticoid sensitivity in the absence of hypercortisolism and to the pathogenesis of AIDS. PMID:9874563

  1. 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}.

  2. 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

  3. 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…

  4. 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

  5. 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…

  6. The transcriptional coactivator Cbp regulates self-renewal and differentiation in adult hematopoietic stem cells.

    PubMed

    Chan, Wai-In; Hannah, Rebecca L; Dawson, Mark A; Pridans, Clare; Foster, Donna; Joshi, Anagha; Göttgens, Berthold; Van Deursen, Jan M; Huntly, Brian J P

    2011-12-01

    The transcriptional coactivator Cbp plays an important role in a wide range of cellular processes, including proliferation, differentiation, and apoptosis. Although studies have shown its requirement for hematopoietic stem cell (HSC) development, its role in adult HSC maintenance, as well as the cellular and molecular mechanisms underlying Cbp function, is not clear. Here, we demonstrate a gradual loss of phenotypic HSCs and differentiation defects following conditional ablation of Cbp during adult homeostasis. In addition, Cbp-deficient HSCs reconstituted hematopoiesis with lower efficiency than their wild-type counterparts, and this response was readily exhausted under replicative stress. This phenotype relates to an alteration in cellular fate decisions for HSCs, with Cbp loss leading to an increase in differentiation, quiescence, and apoptosis. Genome-wide analyses of Cbp occupancy and differential gene expression upon Cbp deletion identified HSC-specific genes regulated by Cbp, providing a molecular basis for the phenotype. Finally, Cbp binding significantly overlapped at genes combinatorially bound by 7 major hematopoietic transcriptional regulators, linking Cbp to a critical HSC transcriptional regulatory network. Our data demonstrate that Cbp plays a role in adult HSC homeostasis by maintaining the balance between different HSC fate decisions, and our findings identify a putative HSC-specific transcriptional network coordinated by Cbp.

  7. NCOA4 transcriptional coactivator inhibits activation of DNA replication origins.

    PubMed

    Bellelli, Roberto; Castellone, Maria Domenica; Guida, Teresa; Limongello, Roberto; Dathan, Nina Alayne; Merolla, Francesco; Cirafici, Anna Maria; Affuso, Andrea; Masai, Hisao; Costanzo, Vincenzo; Grieco, Domenico; Fusco, Alfredo; Santoro, Massimo; Carlomagno, Francesca

    2014-07-01

    NCOA4 is a transcriptional coactivator of nuclear hormone receptors that undergoes gene rearrangement in human cancer. By combining studies in Xenopus laevis egg extracts and mouse embryonic fibroblasts (MEFs), we show here that NCOA4 is a minichromosome maintenance 7 (MCM7)-interacting protein that is able to control DNA replication. Depletion-reconstitution experiments in Xenopus laevis egg extracts indicate that NCOA4 acts as an inhibitor of DNA replication origin activation by regulating CMG (CDC45/MCM2-7/GINS) helicase. NCOA4(-/-) MEFs display unscheduled origin activation and reduced interorigin distance; this results in replication stress, as shown by the presence of fork stalling, reduction of fork speed, and premature senescence. Together, our findings indicate that NCOA4 acts as a regulator of DNA replication origins that helps prevent inappropriate DNA synthesis and replication stress.

  8. The association between antagonist hamstring coactivation and episodes of knee joint shifting and buckling

    PubMed Central

    Segal, N.A.; Nevitt, M.C.; Welborn, R.D.; Nguyen, U.-S.D.T.; Niu, J.; Lewis, C.E.; Felson, D.T.; Frey-Law, L.

    2016-01-01

    SUMMARY Objective Hamstring coactivation during quadriceps activation is necessary to counteract the quadriceps pull on the tibia, but coactivation can be elevated with symptomatic knee osteoarthritis (OA). To guide rehabilitation to attenuate risk for mobility limitations and falls, this study evaluated whether higher antagonistic open kinetic chain hamstring coactivation is associated with knee joint buckling (sudden loss of support) and shifting (a sensation that the knee might give way). Design At baseline, median hamstring coactivation was assessed during maximal isokinetic knee extensor strength testing and at baseline and 24-month follow-up, knee buckling and shifting was self-reported. Associations between tertiles of co-activation and knee (1) buckling, (2) shifting and (3) either buckling or shifting were assessed using logistic regression, adjusted for age, sex, knee OA and pain. Results 1826 participants (1089 women) were included. Mean ± SD age was 61.7 ± 7.7 years, BMI was 30.3 ± 5.5 kg/m2 and 38.2% of knees had OA. There were no consistent statistically significant associations between hamstring coactivation and ipsilateral prevalent or incident buckling or the combination of buckling and shifting. The odds ratios for incident shifting in the highest in comparison with the lowest tertile of coactivation had similar magnitudes in the combined and medial hamstrings, but only reached statistical significance for lateral hamstring coactivation, OR(95%CI) 1.53 (0.99, 2.36). Conclusions Hamstring coactivation during an open kinetic chain quadriceps exercise was not consistently associated with prevalent or incident self-reported knee buckling or shifting in older adults with or at risk for knee OA. PMID:25765501

  9. 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

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. Functional insights from structures of coactivator-associated arginine methyltransferase 1 domains.

    PubMed

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

    2007-10-17

    Coactivator-associated arginine methyltransferase 1 (CARM1), a protein arginine methyltransferase recruited by several transcription factors, methylates a large variety of proteins and plays a critical role in gene expression. We report, in this paper, four crystal structures of isolated modules of CARM1. The 1.7 A crystal structure of the N-terminal domain of CARM1 reveals an unexpected PH domain, a scaffold frequently found to regulate protein-protein interactions in a large variety of biological processes. Three crystal structures of the CARM1 catalytic module, two free and one cofactor-bound forms (refined at 2.55 A, 2.4 A and 2.2 A, respectively) reveal large structural modifications including disorder to order transition, helix to strand transition and active site modifications. The N-terminal and the C-terminal end of CARM1 catalytic module contain molecular switches that may inspire how CARM1 regulates its biological activities by protein-protein interactions.

  15. 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

  16. 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

  17. 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

  18. The transcriptional coactivator SAYP is a trithorax group signature subunit of the PBAP chromatin remodeling complex.

    PubMed

    Chalkley, Gillian E; Moshkin, Yuri M; Langenberg, Karin; Bezstarosti, Karel; Blastyak, Andras; Gyurkovics, Henrik; Demmers, Jeroen A A; Verrijzer, C Peter

    2008-05-01

    SWI/SNF ATP-dependent chromatin remodeling complexes (remodelers) perform critical functions in eukaryotic gene expression control. BAP and PBAP are the fly representatives of the two evolutionarily conserved major subclasses of SWI/SNF remodelers. Both complexes share seven core subunits, including the Brahma ATPase, but differ in a few signature subunits; POLYBROMO and BAP170 specify PBAP, whereas OSA defines BAP. Here, we show that the transcriptional coactivator and PHD finger protein SAYP is a novel PBAP subunit. Biochemical analysis established that SAYP is tightly associated with PBAP but absent from BAP. SAYP, POLYBROMO, and BAP170 display an intimately overlapping distribution on larval salivary gland polytene chromosomes. Genome-wide expression analysis revealed that SAYP is critical for PBAP-dependent transcription. SAYP is required for normal development and interacts genetically with core- and PBAP-selective subunits. Genetic analysis suggested that, like BAP, PBAP also counteracts Polycomb silencing. SAYP appears to be a key architectural component required for the integrity and association of the PBAP-specific module. We conclude that SAYP is a signature subunit that plays a major role in the functional specificity of the PBAP holoenzyme.

  19. BAP18 coactivates androgen receptor action and promotes prostate cancer progression

    PubMed Central

    Sun, Shiying; Zhong, Xinping; Wang, Chunyu; Sun, Hongmiao; Wang, Shengli; Zhou, Tingting; Zou, Renlong; Lin, Lin; Sun, Ning; Sun, Ge; Wu, Yi; Wang, Botao; Song, Xiaoyu; Cao, Liu; Zhao, Yue

    2016-01-01

    BPTF associated protein of 18 kDa (BAP18) has been reported as a component of MLL1-WDR5 complex. However, BAP18 is an uncharacterized protein. The detailed biological functions of BAP18 and underlying mechanisms have not been defined. Androgen receptor (AR), a member of transcription factor, plays an essential role in prostate cancer (PCa) and castration-resistant prostate cancer (CRPC) progression. Here, we demonstrate that BAP18 is identified as a coactivator of AR in Drosophilar experimental system and mammalian cells. BAP18 facilitates the recruitment of MLL1 subcomplex and AR to androgen-response element (ARE) of AR target genes, subsequently increasing histone H3K4 trimethylation and H4K16 acetylation. Knockdown of BAP18 attenuates cell growth and proliferation of PCa cells. Moreover, BAP18 depletion results in inhibition of xenograft tumor growth in mice even under androgen-depletion conditions. In addition, our data show that BAP18 expression in clinical PCa samples is higher than that in benign prostatic hyperplasia (BPH). Our data suggest that BAP18 as an epigenetic modifier regulates AR-induced transactivation and the function of BAP18 might be targeted in human PCa to promote tumor growth and progression to castration-resistance. PMID:27226492

  20. Steroid receptor coactivators as therapeutic targets in the female reproductive system.

    PubMed

    Szwarc, Maria M; Lydon, John P; O'Malley, Bert W

    2015-11-01

    The steroid receptor coactivators (SRCs/p160/NCOA) are a family of three transcriptional coregulators initially discovered to transactivate the transcriptional potency of steroid hormone receptors. Even though SRCs were also found to modulate the activity of multiple other transcription factors, their function is still strongly associated with regulation of steroid hormone action and many studies have found that they are critical for the regulation of reproductive biology. In the case of the female reproductive tract, SRCs have been found to play crucial roles in its physiology, ranging from ovulation, implantation, to parturition. Not surprisingly, SRCs' action has been linked to numerous abnormalities and debilitating disorders of female reproductive tissues, including infertility, cancer, and endometriosis. Many of these pathologies are still in critical need of therapeutic intervention and "proof-of-principle" studies have found that SRCs are excellent targets in pathological states. Therefore, small molecule modulators of SRCs' activity could be applied in the future in the treatment of many diseases of the female reproductive system.

  1. Transcriptional activation in vitro by the human immunodeficiency virus type 1 Tat protein: evidence for specific interaction with a coactivator(s).

    PubMed Central

    Song, C Z; Loewenstein, P M; Green, M

    1994-01-01

    The Tat protein encoded by human immunodeficiency virus type 1 is a strong transcriptional activator of gene expression from the viral long terminal repeat and is essential for virus replication. We have investigated the molecular mechanism of Tat trans-activation by using a cell-free transcription system. We find that the trans-activation domain of Tat, amino acid residues 1-48 [Tat-(1-48)], can inhibit specifically--i.e., "squelch," transcriptional activation by full-length Tat [Tat-(1-86)]. Squelching depends upon the functional integrity of the Tat trans-activation domain because the mutant [Ala41]Tat-(1-48), which is defective in Tat trans-activation in vivo and in vitro, does not squelch in vitro Tat trans-activation. Inhibition is selective because Tat-activated transcription, but not Tat-independent transcription, is squelched. Preincubation experiments with Tat or Tat-(1-48) and nuclear extracts show that the trans-activation region of Tat can interact with cellular coactivator(s) required for Tat trans-activation and that this interaction can occur in the absence of the human immunodeficiency virus long terminal repeat promoter. Furthermore, the putative coactivator(s) mediating trans-activation by Tat differ from those mediating trans-activation by the acidic activator VP16, as shown by reciprocal squelching experiments in vitro. Our results suggest that specific cellular coactivator(s) are required for mediating activated transcription by human immunodeficiency virus type 1 Tat. Images PMID:7937769

  2. Lower limb antagonist muscle co-activation and its relationship with gait parameters in cerebellar ataxia.

    PubMed

    Mari, Silvia; Serrao, Mariano; Casali, Carlo; Conte, Carmela; Martino, Giovanni; Ranavolo, Alberto; Coppola, Gianluca; Draicchio, Francesco; Padua, Luca; Sandrini, Giorgio; Pierelli, Francesco

    2014-04-01

    Increased antagonist muscle co-activation, seen in motor-impaired individuals, is an attempt by the neuromuscular system to provide mechanical stability by stiffening joints. The aim of this study was to investigate the co-activation pattern of the antagonist muscles of the ankle and knee joints during walking in patients with cerebellar ataxia, a neurological disease that strongly affects stability. Kinematic and electromyographic parameters of gait were recorded in 17 patients and 17 controls. Ankle and knee antagonist muscle co-activation indexes were measured throughout the gait cycle and during the sub-phases of gait. The indexes of ataxic patients were compared with those of controls and correlated with clinical and gait variables. Patients showed increased co-activity indexes of both ankle and knee muscles during the gait cycle as well as during the gait sub-phases. Both knee and ankle muscle co-activation indexes were positively correlated with disease severity, while ankle muscle co-activation was also positively correlated with stance and swing duration variability. Significant negative correlations were observed between the number of self-reported falls per year and knee muscle co-activation. The increased co-activation observed in these cerebellar ataxia patients may represent a compensatory strategy serving to reduce gait instability. Indeed, this mechanism allows patients to reduce the occurrence of falls. The need for this strategy, which results in excessive muscle co-contraction, increased metabolic costs and cartilage degeneration processes, could conceivably be overcome through the use of supportive braces specially designed to provide greater joint stability.

  3. Sizn1 is a novel protein that functions as a transcriptional coactivator of bone morphogenic protein signaling.

    PubMed

    Cho, Ginam; Lim, Youngshin; Zand, Dina; Golden, Jeffrey A

    2008-03-01

    Bone morphogenic proteins (BMPs) play pleotrophic roles in nervous system development, and their signaling is highly regulated at virtually every step in the pathway. We have cloned a novel gene, Sizn1 (Smad-interacting zinc finger protein), which functions as a transcriptional coactivator of BMP signaling. It positively modulates BMP signaling by interacting with Smad family members and associating with CBP in the transcription complex. Sizn1 is expressed in the ventral embryonic forebrain, where, as we will show, it contributes to BMP-dependent, cholinergic-neuron-specific gene expression. These data indicate that Sizn1 is a positive modulator of BMP signaling and provide further insight into how BMP signaling can be modulated in neuronal progenitor subsets to influence cell-type-specific gene expression and development.

  4. 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

  5. The transcriptional coactivator TAZ regulates mesenchymal differentiation in malignant glioma.

    PubMed

    Bhat, Krishna P L; Salazar, Katrina L; Balasubramaniyan, Veerakumar; Wani, Khalida; Heathcock, Lindsey; Hollingsworth, Faith; James, Johanna D; Gumin, Joy; Diefes, Kristin L; Kim, Se Hoon; Turski, Alice; Azodi, Yasaman; Yang, Yuhui; Doucette, Tiffany; Colman, Howard; Sulman, Erik P; Lang, Frederick F; Rao, Ganesh; Copray, Sjef; Vaillant, Brian D; Aldape, Kenneth D

    2011-12-15

    Recent molecular classification of glioblastoma (GBM) has shown that patients with a mesenchymal (MES) gene expression signature exhibit poor overall survival and treatment resistance. Using regulatory network analysis of available expression microarray data sets of GBM, including The Cancer Genome Atlas (TCGA), we identified the transcriptional coactivator with PDZ-binding motif (TAZ), to be highly associated with the MES network. TAZ expression was lower in proneural (PN) GBMs and lower-grade gliomas, which correlated with CpG island hypermethylation of the TAZ promoter compared with MES GBMs. Silencing of TAZ in MES glioma stem cells (GSCs) decreased expression of MES markers, invasion, self-renewal, and tumor formation. Conversely, overexpression of TAZ in PN GSCs as well as murine neural stem cells (NSCs) induced MES marker expression and aberrant osteoblastic and chondrocytic differentiation in a TEAD-dependent fashion. Using chromatin immunoprecipitation (ChIP), we show that TAZ is directly recruited to a majority of MES gene promoters in a complex with TEAD2. The coexpression of TAZ, but not a mutated form of TAZ that lacks TEAD binding, with platelet-derived growth factor-B (PDGF-B) resulted in high-grade tumors with MES features in a murine model of glioma. Our studies uncover a direct role for TAZ and TEAD in driving the MES differentiation of malignant glioma.

  6. Transcriptional coactivator PGC-1alpha promotes peroxisomal remodeling and biogenesis.

    PubMed

    Bagattin, Alessia; Hugendubler, Lynne; Mueller, Elisabetta

    2010-11-23

    Mitochondria and peroxisomes execute some analogous, nonredundant functions including fatty acid oxidation and detoxification of reactive oxygen species, and, in response to select metabolic cues, undergo rapid remodeling and division. Although these organelles share some components of their division machinery, it is not known whether a common regulator coordinates their remodeling and biogenesis. Here we show that in response to thermogenic stimuli, peroxisomes in brown fat tissue (BAT) undergo selective remodeling and expand in number and demonstrate that ectopic expression of the transcriptional coactivator PGC-1α recapitulates these effects on the peroxisomal compartment, both in vitro and in vivo. Conversely, β-adrenergic stimulation of PGC-1α(-/-) cells results in blunted induction of peroxisomal gene expression. Surprisingly, PPARα was not required for the induction of critical biogenesis factors, suggesting that PGC-1α orchestrates peroxisomal remodeling through a PPARα-independent mechanism. Our data suggest that PGC-1α is critical to peroxisomal physiology, establishing a role for this factor as a fundamental orchestrator of cellular adaptation to energy demands.

  7. Effect of submaximal repetitive exercise on knee coactivation in young and middle-aged women.

    PubMed

    Hodder, Joanne N; Plashkes, Tova E; Franklin, Regan A; Hickey, Heather K; Maly, Monica R

    2014-04-01

    Coactivation of the knee extensors and flexors increases knee joint contact forces, which may lead to degradation of the articular surfaces. This study investigated the effect of neuromuscular fatigue induced by submaximal, repetitive, dynamic contractions on coactivation of knee musculature in young and middle-aged women. Data from 10 young women (24.6±1.8 years) and 8 middle-aged women (55.4±4.2 years) were analyzed. Measures included peak knee extension and flexion torques and the average amplitude of surface electromyography of rectus femoris and biceps femoris. Coactivation ratios were calculated from these activations. To induce fatigue, participants completed up to ten sets of 50 concentric knee extension and flexion contractions at 60°/s. A two-factor analysis of variance was used to determine the effect of age and fatigue. The young group showed higher peak torque compared with the middle-aged group (P<.001). During flexion, biceps femoris activity increased after fatigue when both groups were considered together (P=.018). During extension, biceps femoris activity was higher in the middle-aged than young group (P=.043). Middle-aged women exhibited a trend for greater coactivation during knee extension compared with young women (P=.066). This coactivation likely contributed to extension torque decrements in middle-aged women.

  8. 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.

  9. Bacteria and their cell wall components uniformly co-activate interleukin-17-producing thymocytes

    PubMed Central

    Weber, A; Zimmermann, C; Kieseier, B C; Hartung, H-P; Hofstetter, H H

    2014-01-01

    Interleukin (IL)-17-producing T cells play a critical role in the immune response against microbial pathogens. Traditionally, experimental studies have focused upon understanding the activity of IL-17-producing T cells which differentiate from naive T cells in the peripheral immune system. However, we have demonstrated previously that IL-17-producing T cells are also present in the thymus of naive wild-type mice and can be co-activated there by microbial stimuli. Other studies have supported the concept that IL-17-producing thymocytes have a specific role in the immediate defence against microbial pathogens, which is independent from the development of an adaptive immune response. Given an important role of the thymus in systemic bacterial infection and sepsis, in this study we investigate the effect of a broad spectrum of bacteria and cell wall components on thymocyte cytokine production. Surprisingly, we find that all types of bacteria investigated (including non-pathogenic species) uniformly activate IL-17-producing thymocytes upon α-CD3 stimulation. In contrast, there is a heterogeneous effect on IL-6 and interferon (IFN)-γ-production with Gram-negative bacteria inducing far higher frequencies of IL-6- and IFN-γ-producing thymocytes than Gram-positive bacteria. We conclude that IL-17-producing thymocytes constitute a ‘first line of recognition’, but not a ‘first line of defence’ against bacteria in general. Their activity might lead to immune activation, but not necessarily to a pathological inflammatory disease condition. The difference between these two states might be determined by other immunological effector molecules, such as IL-6 and IFN-γ. PMID:24995465

  10. The Hippo coactivator YAP1 mediates EGFR overexpression and confers chemo-resistance in esophageal cancer

    PubMed Central

    Song, Shumei; Honjo, Soichiro; Jin, Jiankang; Chang, Shih-Shin; Scott, Ailing W; Chen, Qiongrong; Kalhor, Neda; Correa, Arlene M.; Hofstetter, Wayne L.; Albarracin, Constance T.; Wu, Tsung-Teh; Johnson, Randy L.; Hung, Mien-Chie; Ajani, Jaffer A.

    2015-01-01

    Purpose Esophageal cancer (EC) is an aggressive malignancy and often resistant to therapy. Overexpression of EGFR has been associated with poor prognosis of EC patients. However, clinical trials using EGFR inhibitors have not provided benefit for EC patients. Failure of EGFR inhibition may be due to crosstalk with other oncogenic pathways. Experimental Design In this study, expression of YAP1 and EGFR were examined in EAC resistant tumor tissues vs sensitive tissues by immunohistochemistry. Western blot, immunofluorescence, real-time PCR, promoter analysis, site-directed mutagenesis and in vitro and in vivo functional assays were performed to elucidate the YAP1 mediate EGFR expression and transcription and the relationship with chemoresistance in esophageal cancer. Results We demonstrate that Hippo pathway coactivator YAP1 can induce EGFR expression and transcription in multiple cell systems. Both YAP1 and EGFR are overexpressed in resistant EC tissues compared to sensitive EC tissues. Further, we found that YAP1 increases EGFR expression at the level of transcription requiring an intact TEAD binding site in the EGFR promoter. Most importantly, exogenous induction of YAP1 induces resistance to 5-FU and docetaxcel, while knockdown of YAP sensitizes EC cells to these cytotoxics. Verteporfin, a YAP1 inhibitor, effectively inhibits both YAP1 and EGFR expression and sensitizes cells to cytotoxics. Conclusions Our data provide evidence that YAP1 up-regulation of EGFR plays an important role in conferring therapy resistance in EC cells. Targeting YAP1-EGFR axis may be more efficacious than targeting EGFR alone in EC. PMID:25739674

  11. 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

  12. 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

  13. Coherence of coactivation and acceleration in task-specific primary bowing tremor.

    PubMed

    Lee, André; Tominaga, Kenta; Furuya, Shinichi; Miyazaki, Fumio; Altenmüller, Eckart

    2014-07-01

    Coherences between coactivation of wrist antagonist muscles and movement fluctuation were assessed in four violinists with a task-specific tremor and four age-matched healthy violinists using electromyography and accelerometer. We found coherence between individual muscular activation and tremor only in patients at a frequency range of 3-8 Hz. The finding corroborates the notion that primary bowing tremor emerges mainly due to central neurogenic contributions via motor-unit synchronization. Furthermore, the coherence between the muscular coactivation and tremor suggests a relation of the tremor to dystonia.

  14. CREB and the CRTC co-activators: sensors for hormonal and metabolic signals.

    PubMed

    Altarejos, Judith Y; Montminy, Marc

    2011-03-01

    The cyclic AMP-responsive element-binding protein (CREB) is phosphorylated in response to a wide variety of signals, yet target gene transcription is only increased in a subset of cases. Recent studies indicate that CREB functions in concert with a family of latent cytoplasmic co-activators called cAMP-regulated transcriptional co-activators (CRTCs), which are activated through dephosphorylation. A dual requirement for CREB phosphorylation and CRTC dephosphorylation is likely to explain how these activator-co-activator cognates discriminate between different stimuli. Following their activation, CREB and CRTCs mediate the effects of fasting and feeding signals on the expression of metabolic programmes in insulin-sensitive tissues.

  15. A key role of PGC-1α transcriptional coactivator in production of VEGF by a novel angiogenic agent COA-Cl in cultured human fibroblasts.

    PubMed

    Igarashi, Junsuke; Okamoto, Ryuji; Yamashita, Tetsuo; Hashimoto, Takeshi; Karita, Sakiko; Nakai, Kozo; Kubota, Yasuo; Takata, Maki; Yamaguchi, Fuminori; Tokuda, Masaaki; Sakakibara, Norikazu; Tsukamoto, Ikuko; Konishi, Ryoji; Hirano, Katsuya

    2016-03-01

    We previously demonstrated a potent angiogenic effect of a newly developed adenosine-like agent namedCOA-Cl.COA-Cl exerted tube forming activity in human umbilical vein endothelial cells in the presence of normal human dermal fibroblasts (NHDF). We therefore explored whether and howCOA-Cl modulates gene expression and protein secretion ofVEGF, a master regulator of angiogenesis, inNHDFRT-PCRandELISArevealed thatCOA-Cl upregulatedVEGF mRNAexpression and protein secretion inNHDFHIF1α(hypoxia-inducible factor 1α), a transcription factor, andPGC-1α(peroxisome proliferator-activated receptor-γcoactivator-1α), a transcriptional coactivator, are known to positively regulate theVEGFgene. Immunoblot andRT-PCRanalyses revealed thatCOA-Cl markedly upregulated the expression ofPGC-1αprotein andmRNACOA-Cl had no effect on the expression ofHIF1αprotein andmRNAin both hypoxia and normoxia. SilencingPGC-1αgene, but notHIF1αgene, by small interferingRNAattenuated the ability ofCOA-Cl to promoteVEGFsecretion. When an N-terminal fragment ofPGC-1αwas cotransfected with its partner transcription factorERRα(estrogen-related receptor-α) inCOS-7 cells,COA-Cl upregulated the expression of the endogenousVEGF mRNA However,COA-Cl had no effect on the expression ofVEGF, whenHIF1αwas transfected.COA-Cl inducesVEGFgene expression and protein secretion in fibroblasts. The transcriptional coactivatorPGC-1α, in concert withERRα, plays a key role in theCOA-Cl-inducedVEGFproduction.COA-Cl-induced activation ofPGC-1α-ERRα-VEGFpathway has a potential as a novel means for therapeutic angiogenesis.

  16. Blocking Estrogen Signaling After the Hormone: Pyrimidine-Core Inhibitors of Estrogen Receptor-Coactivator Binding

    PubMed Central

    Parent, Alexander A.; Gunther, Jillian R.; Katzenellenbogen, John A.

    2009-01-01

    As an alternative approach to blocking estrogen action, we have developed small molecules that directly disrupt the key estrogen receptor (ER)/coactivator interaction necessary for gene activation. The more direct, protein-protein nature of this disruption might be effective even in hormone-refractory breast cancer. We have synthesized a pyrimidine-core library of moderate size, members of which act as α-helix mimics to block ERα/coactivator interaction. Structure- activity relationships have been explored with various C, N, O and S-substituents on the pyrimidine core. Time-resolved fluorescence resonance energy transfer and cell-based reporter gene assays show that the most active members inhibit the ERα/steroid receptor coactivator interaction with Ki’s in the low micromolar range. Through these studies, we have obtained a refined pharmacophore model for activity in this pyrimidine series. Furthermore, the favorable activities of several of these compounds support the feasibility that this coactivator binding inhibition mechanism for blocking estrogen action might provide a potential alternative approach to endocrine therapy. PMID:18785725

  17. Overexpression of the coactivator bridge-1 results in insulin deficiency and diabetes.

    PubMed

    Volinic, Jamie L; Lee, Jee H; Eto, Kazuhiro; Kaur, Varinderpal; Thomas, Melissa K

    2006-01-01

    Multiple forms of heritable diabetes are associated with mutations in transcription factors that regulate insulin gene transcription and the development and maintenance of pancreatic beta-cell mass. The coactivator Bridge-1 (PSMD9) regulates the transcriptional activation of glucose-responsive enhancers in the insulin gene in a dose-dependent manner via PDZ domain-mediated interactions with E2A transcription factors. Here we report that the pancreatic overexpression of Bridge-1 in transgenic mice reduces insulin gene expression and results in insulin deficiency and severe diabetes. Dysregulation of Bridge-1 signaling increases pancreatic apoptosis with a reduction in the number of insulin-expressing pancreatic beta-cells and an expansion of the complement of glucagon-expressing pancreatic alpha-cells in pancreatic islets. Increased expression of Bridge-1 alters pancreatic islet, acinar, and ductal architecture and disrupts the boundaries between endocrine and exocrine cellular compartments in young adult but not neonatal mice, suggesting that signals transduced through this coactivator may influence postnatal pancreatic islet morphogenesis. Signals mediated through the coactivator Bridge-1 may regulate both glucose homeostasis and pancreatic beta-cell survival. We propose that coactivator dysfunction in pancreatic beta-cells can limit insulin production and contribute to the pathogenesis of diabetes.

  18. 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…

  19. Synergic co-activation of muscles in elbow flexion via fractional Brownian motion.

    PubMed

    Chang, Shyang; Hsyu, Ming-Chun; Cheng, Hsiu-Yao; Hsieh, Sheng-Hwu

    2008-12-31

    In reflex and volitional actions, co-activations of agonist and antagonist muscles are believed to be present. Recent studies indicate that such co-activations can be either synergic or dyssynergic. The aim of this paper is to investigate if the co-activations of biceps brachii, brachialis, and triceps brachii during volitional elbow flexion are in the synergic or dyssynergic state. In this study, two groups with each containing six healthy male volunteers participated. Each person of the first group performed 30 trials of volitional elbow flexion while each of the second group performed 30 trials of passive elbow flexion as control experiments. Based on the model of fractional Brownian motion, the intensity and frequency information of the surface electromyograms (EMGs) could be extracted simultaneously. No statistically significant changes were found in the control group. As to the other group, results indicated that the surface EMGs of all five muscle groups were temporally synchronized in frequencies with persistent intensities during each elbow flexion. In addition, the mean values of fractal dimensions for rest and volitional flexion states revealed significant differences with P < 0.01. The obtained positive results suggest that these muscle groups work together synergically to facilitate elbow flexion during the co-activations.

  20. Superficial shoulder muscle co-activations during lifting tasks: Influence of lifting height, weight and phase.

    PubMed

    Blache, Y; Dal Maso, F; Desmoulins, L; Plamondon, A; Begon, M

    2015-04-01

    This study aimed to assess the level of co-activation of the superficial shoulder muscles during lifting movement. Boxes containing three different loads (6, 12, and 18 kg) were lifted by fourteen subjects from the waist to shoulder or eye level. The 3D kinematics and electromyograms of the three deltoids, latissimus dorsi and pectoralis major were recorded. A musculoskeletal model was used to determine direction of the moment arm of these muscles. Finally an index of muscle co-activation named the muscle focus was used to evaluate the effects of lifting height, weight lifted and phase (pulling, lifting and dropping phases) on superficial shoulder muscle coactivation. The muscle focus was lower (more co-contraction) during the dropping phase compared to the two other phases (-13%, p<0.001). This was explained by greater muscle activations and by a change in the direction of the muscle moment arm as a function of glenohumeral joint position. Consequently, the function of the shoulder superficial muscles varied with respect to the glenohumeral joint position. To increase the superficial muscle coactivation during the dropping phase may be a solution to increase glenohumeral joint stiffness.

  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. Nuclear receptor coactivators facilitate vitamin D receptor homodimer action on direct repeat hormone response elements.

    PubMed

    Takeshita, A; Ozawa, Y; Chin, W W

    2000-03-01

    Vitamin D receptor (VDR) is a ligand-dependent transcription factor that regulates target gene expression. Although VDR forms stable heterodimer complex with retinoid X receptors (RXRs) on vitamin D-response elements (VDREs), it is still not clear whether VDR/RXR heterodimers are the only VDR complexes responsible for vitamin D-mediated gene transcription. In this report, we analyzed the effect of nuclear receptor coactivators (SRC-1 and TRAM-1) on VDR homodimer and VDR/RXR heterodimer formation by electrophoretic mobility shift assay. We found that VDR forms stable homodimers after interaction with the coactivators on a VDRE (DR+3). Of particular note, DR+4 and DR+5 hormone-response elements (HREs) may also support such interactions. Cotransfection experiments revealed further that the coactivators enhance ligand-induced VDR transcription on these elements. Our studies suggest the important role of VDR homodimers, in addition to VDR/RXR heterodimers, in vitamin D-induced transactivation. Thus, specific coactivator-VDR interactions on HREs may determine target gene transactivation.

  3. 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…

  4. Bipartite functions of the CREB co-activators selectively direct alternative splicing or transcriptional activation.

    PubMed

    Amelio, Antonio L; Caputi, Massimo; Conkright, Michael D

    2009-09-16

    The CREB regulated transcription co-activators (CRTCs) regulate many biological processes by integrating and converting environmental inputs into transcriptional responses. Although the mechanisms by which CRTCs sense cellular signals are characterized, little is known regarding how CRTCs contribute to the regulation of cAMP inducible genes. Here we show that these dynamic regulators, unlike other co-activators, independently direct either pre-mRNA splice-site selection or transcriptional activation depending on the cell type or promoter context. Moreover, in other scenarios, the CRTC co-activators coordinately regulate transcription and splicing. Mutational analyses showed that CRTCs possess distinct functional domains responsible for regulating either pre-mRNA splicing or transcriptional activation. Interestingly, the CRTC1-MAML2 oncoprotein lacks the splicing domain and is incapable of altering splice-site selection despite robustly activating transcription. The differential usage of these distinct domains allows CRTCs to selectively mediate multiple facets of gene regulation, indicating that co-activators are not solely restricted to coordinating alternative splicing with increase in transcriptional activity.

  5. 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...

  6. 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

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

    PubMed

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

    2010-06-01

    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.

  8. Evaluation of antagonist coactivation strategies elicited from electrically stimulated muscles under load-moving conditions.

    PubMed

    Zhou, B H; Katz, S R; Baratta, R V; Solomonow, M; D'Ambrosia, R D

    1997-07-01

    Muscle coactivation strategies that produce ankle dorsiflexion and plantar flexion were elicited by electrical stimulation of the tibialis anterior (TA) and soleus (SOL) muscles of the cat, and examined under several loading conditions. Four different load types were used: free-limb motion (no load), fly-wheel, and two pendulums, each with a different lever arm. Three types of coactivation strategies were considered. The first coactivation strategy consisted of antagonist activity that decreased as the agonist activity increased. The second strategy consisted of increasing antagonist activity with increasing agonist activity. And, in the third strategy, antagonist coactivation decreased at low force levels, then increased at high force levels. The three strategies were evaluated based on the joint angle's peak-to-peak movement and its ability to track a linear input command given by the correlation coefficient of the output signal versus linear input. Results showed that increasing antagonist activity resulted in decreasing peak-to-peak angle and a decreased signal tracking capability for each load condition. The latter, however, was not as obvious in the flywheel load (as compared with free-moving and pendulum conditions). A decreasing peak-to-peak torque for pendulum loads was also observed with increasing antagonist activity. In all loading conditions, maximal peak-to-peak angle and torque were present when a moderate degree of antagonist activity was engaged, and signal tracking capability improved with earlier engagement of the antagonist muscles. It is suggested that strategies using a combination of low-level coactivation, as described in the physiological literature and previous functional electrical stimulation (FES) studies, could satisfactorily address the issues of controllability and efficiency while maintaining long-term joint integrity.

  9. 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.

  10. Krüppel-like factor 6 is a co-activator of NF-κB that mediates p65-dependent transcription of selected downstream genes.

    PubMed

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

    2014-05-01

    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.

  11. Macrophage PPAR gamma Co-activator-1 alpha participates in repressing foam cell formation and atherosclerosis in response to conjugated linoleic acid

    PubMed Central

    McCarthy, Cathal; Lieggi, Nora T; Barry, Denis; Mooney, Declan; de Gaetano, Monica; James, William G; McClelland, Sarah; Barry, Mary C; Escoubet-Lozach, Laure; Li, Andrew C; Glass, Christopher K; Fitzgerald, Desmond J; Belton, Orina

    2013-01-01

    Conjugated linoleic acid (CLA) has the unique property of inducing regression of pre-established murine atherosclerosis. Understanding the mechanism(s) involved may help identify endogenous pathways that reverse human atherosclerosis. Here, we provide evidence that CLA inhibits foam cell formation via regulation of the nuclear receptor coactivator, peroxisome proliferator-activated receptor (PPAR)-γ coactivator (PGC)-1α, and that macrophage PGC-1α plays a role in atheroprotection in vivo. PGC-1α was identified as a hub gene within a cluster in the aorta of the apoE−/− mouse in the CLA-induced regression model. PGC-1α was localized to macrophage/foam cells in the murine aorta where its expression was increased during CLA-induced regression. PGC-1α expression was also detected in macrophages in human atherosclerosis and was inversely linked to disease progression in patients with the disease. Deletion of PGC-1α in bone marrow derived macrophages promoted, whilst over expression of the gene inhibited foam cell formation. Importantly, macrophage specific deletion of PGC-1α accelerated atherosclerosis in the LDLR−/− mouse in vivo. These novel data support a functional role for PGC-1α in atheroprotection. PMID:23964012

  12. Role of cAMP-responsive element-binding protein (CREB)-regulated transcription coactivator 3 (CRTC3) in the initiation of mitochondrial biogenesis and stress response in liver cells.

    PubMed

    Than, Tin Aung; Lou, Huan; Ji, Cheng; Win, Sanda; Kaplowitz, Neil

    2011-06-24

    Peroxisome proliferator-activated receptor α, coactivator 1α (PGC-1α) is the master regulator of mitochondrial biogenesis. PGC-1α expression is under the control of the transcription factor, cAMP-responsive element-binding protein (CREB). In searching for candidate transcription factors that mediate mitochondrial stress-initiated mitochondria-to-nucleus signaling in the regulation of mitochondrial biogenesis, we assessed the effect of silencing CREB-regulated transcription co-activators (CRTC). CRTC isoforms are co-activators of CREB-regulated transcription by a CREB phosphorylation-independent pathway. Using cultured HepG2 cells and primary mouse hepatocytes, we determined that mitochondrial stress imposed by the complex I inhibitor rotenone elicited mitochondrial biogenesis, which was dependent on an induction of PGC-1α, which was inhibited by silencing PGC-1α. PGC-1α induction in response to rotenone was inhibited by silencing the expression of CRTC3, which blocked downstream mitochondria biogenesis. In contrast, silencing CRTC2 did not affect the induction of this pathway in response to rotenone. Thus, CRTC3 plays a selective role in mitochondrial biogenesis in response to rotenone.

  13. The p160/Steroid Receptor Coactivator Family: Potent Arbiters of Uterine Physiology and Dysfunction1

    PubMed Central

    Szwarc, Maria M.; Kommagani, Ramakrishna; Lessey, Bruce A.; Lydon, John P.

    2014-01-01

    ABSTRACT The p160/steroid receptor coactivator (SRC) family comprises three pleiotropic coregulators (SRC-1, SRC-2, and SRC-3; otherwise known as NCOA1, NCOA2, and NCOA3, respectively), which modulate a wide spectrum of physiological responses and clinicopathologies. Such pleiotropy is achieved through their inherent structural complexity, which allows this coregulator class to control both nuclear receptor and non-nuclear receptor signaling. As observed in other physiologic systems, members of the SRC family have recently been shown to play pivotal roles in uterine biology and pathobiology. In the murine uterus, SRC-1 is required to launch a full steroid hormone response, without which endometrial decidualization is markedly attenuated. From “dovetailing” clinical and mouse studies, an isoform of SRC-1 was recently identified which promotes endometriosis by reprogramming endometrial cells to evade apoptosis and to colonize as endometriotic lesions within the peritoneal cavity. The endometrium fails to decidualize without SRC-2, which accounts for the infertility phenotype exhibited by mice devoid of this coregulator. In related studies on human endometrial stromal cells, SRC-2 was shown to act as a molecular “pacemaker” of the glycolytic flux. This finding is significant because acceleration of the glycolytic flux provides the necessary bioenergy and biomolecules for endometrial stromal cells to switch from quiescence to a proliferative phenotype, a critical underpinning in the decidual progression program. Although studies on uterine SRC-3 function are in their early stages, clinical studies provide tantalizing support for the proposal that SRC-3 is causally linked to endometrial hyperplasia as well as with endometrial pathologies in patients diagnosed with polycystic ovary syndrome. This proposal is now driving the development and application of innovative technologies, particularly in the mouse, to further understand the functional role of this elusive

  14. 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…

  15. Small Molecule Inhibition of the Steroid Receptor Coactivators, SRC-3 and SRC-1

    PubMed Central

    Wang, Ying; Yu, Yang; Chow, Dar-Chone; Palzkill, Timothy G.

    2011-01-01

    Overexpression of steroid receptor coactivator (SRC)-1 and SRC-3 is associated with cancer initiation, metastasis, advanced disease, and resistance to chemotherapy. In most of these cases, SRC-1 and SRC-3 have been shown to promote tumor cell growth by activating nuclear receptor and multiple growth factor signaling cascades that lead to uncontrolled tumor cell growth. Up until now, most targeted chemotherapeutic drugs have been designed largely to block a single pathway at a time, but cancers frequently acquire resistance by switching to alternative growth factor pathways. We reason that the development of chemotherapeutic agents against SRC coactivators that sit at the nexus of multiple cell growth signaling networks and transcriptional factors should be particularly effective therapeutics. To substantiate this hypothesis, we report the discovery of 2,2′-bis-(Formyl-1,6,7-trihydroxy-5-isopropyl-3-methylnaphthalene (gossypol) as a small molecule inhibitor of coactivator SRC-1 and SRC-3. Our data indicate that gossypol binds directly to SRC-3 in its receptor interacting domain. In MCF-7 breast cancer cells, gossypol selectively reduces the cellular protein concentrations of SRC-1 and SRC-3 without generally altering overall protein expression patterns, SRC-2, or other coactivators, such as p300 and coactivator-associated arginine methyltransferase 1. Gossypol reduces the concentration of SRC-3 in prostate, lung, and liver cancer cell lines. Gossypol inhibits cell viability in the same cancer cell lines where it promotes SRC-3 down-regulation. Additionally, gossypol sensitizes lung and breast cancer cell lines to the inhibitory effects of other chemotherapeutic agents. Importantly, gossypol is selectively cytotoxic to cancer cells, whereas normal cell viability is not affected. This data establish the proof-of-principle that, as a class, SRC-1 and SRC-3 coactivators are accessible chemotherapeutic targets. Given their function as integrators of multiple cell

  16. Coactivators p300 and PCAF physically and functionally interact with the foamy viral trans-activator

    PubMed Central

    Bannert, Helmut; Muranyi, Walter; Ogryzko, Vasily V; Nakatani, Yoshihiro; Flügel, Rolf M

    2004-01-01

    Background Foamy virus Bel1/Tas trans-activators act as key regulators of gene expression and directly bind to Bel1 response elements (BRE) in both the internal and the 5'LTR promoters leading to strong transcriptional trans-activation. Cellular coactivators interacting with Bel1/Tas are unknown to date. Results Transient expression assays, co-immunoprecipitation experiments, pull-down assays, and Western blot analysis were used to demonstrate that the coactivator p300 and histone acetyltransferase PCAF specifically interact with the retroviral trans-activator Bel1/Tas in vivo. Here we show that the Bel1/Tas-mediated trans-activation was enhanced by the coactivator p300, histone acetyltransferases PCAF and SRC-1 based on the crucial internal promoter BRE. The Bel1/Tas-interacting region was mapped to the C/H1 domain of p300 by co-immunoprecipitation and pull-down assays. In contrast, coactivator SRC-1 previously reported to bind to the C-terminal domain of p300 did not directly interact with the Bel1 protein but nevertheless enhanced Bel1/Tas-mediated trans-activation. Cotransfection of Bel1/Tas and p300C with an expression plasmid containing the C/H1domain partially inhibited the p300C-driven trans-activation. Conclusions Our data identify p300 and PCAF as functional partner molecules that directly interact with Bel1/Tas. Since the acetylation activities of the three coactivators reside in or bind to the C-terminal regions of p300, a C/H1 expression plasmid was used as inhibitor. This is the first report of a C/H1 domain-interacting retroviral trans-activator capable of partially blocking the strong Bel1/Tas-mediated activation of the C-terminal region of coactivator p300. The potential mechanisms and functional roles of the three histone and factor acetyltransferases p300, PCAF, and SRC-1 in Bel1/Tas-mediated trans-activation are discussed. PMID:15350211

  17. 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

  18. Analyzing phosphorylation-dependent regulation of subcellular localization and transcriptional activity of transcriptional coactivator NT-PGC-1α.

    PubMed

    Chang, Ji Suk; Gettys, Thomas W

    2013-01-01

    Peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α) is a nuclear transcriptional coactivator that regulates the genes involved in energy metabolism. Recent evidence has been provided that alternative splicing of PPARGC1A gene produces a functional but predominantly cytosolic isoform of PGC-1α (NT-PGC-1α). We have demonstrated that transcriptional coactivation capacity of NT-PGC-1α is directly correlated with its nuclear localization in a PKA phosphorylation-dependent manner. In this chapter, we describe quantitative imaging analysis methods that are developed to measure the relative fluorescence intensity of the protein of interest in the nucleus and cytoplasm in a single cell and the frequency distribution of nuclear/cytoplasmic intensity ratios in the population of cells, respectively. This chapter also describes transient cotransfection and dual-luciferase reporter gene assay that examine the ability of coactivators to activate the transcriptional activity of transcription factors.

  19. 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

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. 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

  5. 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

  6. 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.

  7. GSK3beta is a negative regulator of the transcriptional coactivator MAML1.

    PubMed

    Saint Just Ribeiro, Mariana; Hansson, Magnus L; Lindberg, Mikael J; Popko-Scibor, Anita E; Wallberg, Annika E

    2009-11-01

    Glycogen synthase kinase 3beta (GSK3beta) is involved in several cellular signaling systems through regulation of the activity of diverse transcription factors such as Notch, p53 and beta-catenin. Mastermind-like 1 (MAML1) was originally identified as a Notch coactivator, but has also been reported to function as a transcriptional coregulator of p53, beta-catenin and MEF2C. In this report, we show that active GSK3beta directly interacts with the MAML1 N-terminus and decreases MAML1 transcriptional activity, suggesting that GSK3beta might target a coactivator in its regulation of gene expression. We have previously shown that MAML1 increases global acetylation of histones, and here we show that the GSK3 inhibitor SB41, further enhances MAML1-dependent histone acetylation in cells. Finally, MAML1 translocates GSK3beta to nuclear bodies; this function requires full-length MAML1 protein.

  8. 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

  9. 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

  10. Dax-1 and steroid receptor RNA activator (SRA) function as transcriptional coactivators for steroidogenic factor 1 in steroidogenesis.

    PubMed

    Xu, Bin; Yang, Wei-Hsiung; Gerin, Isabelle; Hu, Chang-Deng; Hammer, Gary D; Koenig, Ronald J

    2009-04-01

    The nuclear receptor steroidogenic factor 1 (SF-1) is essential for adrenal development and steroidogenesis. The atypical orphan nuclear receptor Dax-1 binds to SF-1 and represses SF-1 target genes. Paradoxically, however, loss-of-function mutations of Dax-1 also cause adrenal hypoplasia, suggesting that Dax-1 may function as an SF-1 coactivator under some circumstances. Indeed, we found that Dax-1 can function as a dosage-dependent SF-1 coactivator. Both SF-1 and Dax-1 bind to steroid receptor RNA activator (SRA), a coactivator that functions as an RNA. The coactivator TIF2 also associates with Dax-1 and synergistically coactivates SF-1 target gene transcription. A naturally occurring Dax-1 mutation inhibits this transactivation, and the mutant Dax-1-TIF2 complex mislocalizes in living cells. Coactivation by Dax-1 is abolished by SRA knockdown. The expression of the steroidogenic gene products steroidogenic acute regulatory protein (StAR) and melanocortin 2 receptor is reduced in adrenal Y1 cells following the knockdown of endogenous SRA. Similarly, the knockdown of endogenous Dax-1 downregulates the expression of the steroidogenic gene products CYP11A1 and StAR in both H295R adrenal and MA-10 Leydig cells. These findings reveal novel functions of SRA and Dax-1 in steroidogenesis and adrenal biology. PMID:19188450

  11. Dax-1 and Steroid Receptor RNA Activator (SRA) Function as Transcriptional Coactivators for Steroidogenic Factor 1 in Steroidogenesis▿

    PubMed Central

    Xu, Bin; Yang, Wei-Hsiung; Gerin, Isabelle; Hu, Chang-Deng; Hammer, Gary D.; Koenig, Ronald J.

    2009-01-01

    The nuclear receptor steroidogenic factor 1 (SF-1) is essential for adrenal development and steroidogenesis. The atypical orphan nuclear receptor Dax-1 binds to SF-1 and represses SF-1 target genes. Paradoxically, however, loss-of-function mutations of Dax-1 also cause adrenal hypoplasia, suggesting that Dax-1 may function as an SF-1 coactivator under some circumstances. Indeed, we found that Dax-1 can function as a dosage-dependent SF-1 coactivator. Both SF-1 and Dax-1 bind to steroid receptor RNA activator (SRA), a coactivator that functions as an RNA. The coactivator TIF2 also associates with Dax-1 and synergistically coactivates SF-1 target gene transcription. A naturally occurring Dax-1 mutation inhibits this transactivation, and the mutant Dax-1-TIF2 complex mislocalizes in living cells. Coactivation by Dax-1 is abolished by SRA knockdown. The expression of the steroidogenic gene products steroidogenic acute regulatory protein (StAR) and melanocortin 2 receptor is reduced in adrenal Y1 cells following the knockdown of endogenous SRA. Similarly, the knockdown of endogenous Dax-1 downregulates the expression of the steroidogenic gene products CYP11A1 and StAR in both H295R adrenal and MA-10 Leydig cells. These findings reveal novel functions of SRA and Dax-1 in steroidogenesis and adrenal biology. PMID:19188450

  12. A novel meta-analytic approach: mining frequent co-activation patterns in neuroimaging databases.

    PubMed

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

    2014-04-15

    In recent years, coordinate-based meta-analyses have become a powerful and widely used tool to study co-activity 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

  13. 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

  14. E6-associated protein (E6-AP) is a dual function coactivator of steroid hormone receptors

    PubMed Central

    Ramamoorthy, Sivapriya; Nawaz, Zafar

    2008-01-01

    Steroid hormone receptors (SHR) belong to a large family of ligand-activated transcription factors that perform their biological functions by enhancing the transcription of specific target genes. The transactivation functions of SHRs are regulated by a specialized group of proteins called coactivators. The SHR coactivators represent a growing class of proteins with various enzymatic activities that serve to modify the chromatin to facilitate the transcription of SHR target genes. The ubiquitin-proteasome pathway enzymes have also been added to the growing list of enzymatic activities that are recruited to the SHR target gene promoters during transcription. One such ubiquitin-proteasome pathway enzyme to be identified and characterized as a SHR coactivator was E6-associated protein (E6-AP). E6-AP is a hect (homologous to E6-associated protein carboxy-terminal domain) domain containing E3 ubiquitin ligase that possesses two independent separable functions; a coactivation function and an ubiquitin-protein ligase activity. Being a component of the ubiquitin-proteasome pathway, it is postulated that E6-AP may orchestrate the dynamics of steroid hormone receptor-mediated transcription by regulating the degradation of the transcriptional complexes. E6-AP has also been shown to be involved in the regulation of various aspects of reproduction such as prostate and mammary gland development. Furthermore, it has been demonstrated that E6-AP expression is down-regulated in breast and prostate tumors and that the expression of E6-AP is inversely associated with that of estrogen and androgen receptors. This review summarizes our current knowledge about the structures, molecular mechanisms, spatiotemporal expression patterns and biological functions of E6-AP. PMID:18432313

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

    PubMed Central

    Matsui, Teppei; Murakami, Tomonari; Ohki, Kenichi

    2016-01-01

    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

  16. 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

  17. They Too Should Play.

    ERIC Educational Resources Information Center

    Hirst, Cyntha C.; Shelley, Eva Y.

    1989-01-01

    Children with mental retardation and multiple handicaps can effectively participate in play activities and games, but the experience must be structured for them. Techniques for organizing play activities involving handicapped and nonhandicapped children are offered. Examples of singles play, rotation play, and associative play are described. (JDD)

  18. Children's Play and Television.

    ERIC Educational Resources Information Center

    Powell, Mark

    2001-01-01

    Discusses adverse effects of FCC deregulation of children's television programming on children's play behavior. Discusses the difference between play and imitation, the role of high quality dramatic play in healthy child development, the popularity of war play, and use of toys to increase dramatic play. Considers ways to help children gain control…

  19. 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…

  20. 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

  1. SRC-2 is an essential coactivator for orchestrating metabolism and circadian rhythm.

    PubMed

    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

    2014-02-27

    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 circadian clock. PMID:24529706

  2. 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.

  3. 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

  4. 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.

  5. The LIM-only coactivator FHL2 modulates WT1 transcriptional activity during gonadal differentiation.

    PubMed

    Du, Xiaojuan; Hublitz, Philip; Günther, Thomas; Wilhelm, Dagmar; Englert, Christoph; Schüle, Roland

    2002-08-19

    An essential step during sex determination is the maintenance of the Müllerian duct in females and its regression in males caused by the expression of Müllerian inhibiting substance (MIS). In testes, the Wilms' tumor suppressor and the orphan nuclear receptor SF1 cooperatively bind to the promoter and activate transcription of MIS. In the ovaries, on the other hand, the orphan nuclear receptor DAX1 binds to SF1, inhibits transactivation by WT1/SF1 and thereby suppresses the induction of MIS expression. In addition, WT1 itself is responsible for the upregulation of DAX1 transcription. So far, little is known on which protein-protein interactions or cofactors elicit the spatiotemporal control of WT1-mediated transcription. Here we demonstrate coexpression of the LIM-only coactivator FHL2 and WT1. FHL2 and WT1 functionally interact both in vitro and in vivo. The importance of this interaction is revealed by the ability of FHL2 to potentiate the synergistic induction of MIS gene expression by WT1/SF1. Moreover, FHL2 coactivates transactivation of the DAX1 promoter by WT1. Hence, we present FHL2 as a novel transcriptional coactivator of WT1. The ability to modulate both DAX1 and MIS expression might allow FHL2 to act in the molecular fine tuning of WT1-dependent control mechanisms in the reproductive organs.

  6. 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

  7. 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

  8. Hepatitis B virus pX targets TFIIB in transcription coactivation.

    PubMed

    Haviv, I; Shamay, M; Doitsh, G; Shaul, Y

    1998-03-01

    pX, the hepatitis B virus (HBV)-encoded regulator, coactivates transcription through an unknown mechanism. pX interacts with several components of the transcription machinery, including certain activators, TFIIB, TFIIH, and the RNA polymerase II (POLII) enzyme. We show that pX localizes in the nucleus and coimmunoprecipitates with TFIIB from nuclear extracts. We used TFIIB mutants inactive in binding either POLII or TATA binding protein to study the role of TFIIB-pX interaction in transcription coactivation. pX was able to bind the former type of TFIIB mutant and not the latter. Neither of these sets of TFIIB mutants supports transcription. Remarkably, the latter TFIIB mutants fully block pX activity, suggesting the role of TFIIB in pX-mediated coactivation. By contrast, in the presence of pX, TFIIB mutants with disrupted POLII binding acquire the wild-type phenotype, both in vivo and in vitro. These results suggest that pX may establish the otherwise inefficient TFIIB mutant-POLII interaction, by acting as a molecular bridge. Collectively, our results demonstrate that TFIIB is the in vivo target of pX. PMID:9488473

  9. A DNA Repair Complex Functions as an Oct4/Sox2 Coactivator in Embryonic Stem Cells

    PubMed Central

    Fong, Yick W.; Inouye, Carla; Yamaguchi, Teppei; Cattoglio, Claudia; Grubisic, Ivan; Tjian, Robert

    2011-01-01

    SUMMARY The transcriptional activators Oct4, Sox2 and Nanog cooperate with a wide array of cofactors to orchestrate an embryonic stem (ES) cell-specific gene expression program that forms the molecular basis of pluripotency. Here we report using an unbiased in vitro transcription-biochemical complementation assay to discover a multi-subunit stem cell coactivator complex (SCC) that is selectively required for the synergistic activation of the Nanog gene by Oct4 and Sox2. Purification, identification and reconstitution of SCC revealed this coactivator to be the trimeric XPC-nucleotide excision repair complex. SCC interacts directly with Oct4 and Sox2 and is recruited to the Nanog and Oct4 promoters as well as a majority of genomic regions that are occupied by Oct4 and Sox2. Depletion of SCC/XPC compromised both pluripotency in ES cells and somatic cell reprogramming of fibroblasts to induced pluripotent stem (iPS) cells. This study identifies a transcriptional coactivator with diversified functions in maintaining ES cell pluripotency and safeguarding genome integrity. PMID:21962512

  10. 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.

  11. Agonist ligands mediate the transcriptional response of nuclear receptor heterodimers through distinct stoichiometric assemblies with coactivators.

    PubMed

    Pavlin, Mark Remec; Brunzelle, Joseph S; Fernandez, Elias J

    2014-09-01

    The constitutive androstane (CAR) and retinoid X receptors (RXR) are ligand-mediated transcription factors of the nuclear receptor protein superfamily. Functional CAR:RXR heterodimers recruit coactivator proteins, such as the steroid receptor coactivator-1 (SRC1). Here, we show that agonist ligands can potentiate transactivation through both coactivator binding sites on CAR:RXR, which distinctly bind two SRC1 molecules. We also observe that SRC1 transitions from a structurally plastic to a compact form upon binding CAR:RXR. Using small angle x-ray scattering (SAXS) we show that the CAR(tcp):RXR(9c)·SRC1 complex can encompass two SRC1 molecules compared with the CAR(tcp):RXR·SRC1, which binds only a single SRC1. Moreover, sedimentation coefficients and molecular weights determined by analytical ultracentrifugation confirm the SAXS model. Cell-based transcription assays show that disrupting the SRC1 binding site on RXR alters the transactivation by CAR:RXR. These data suggest a broader role for RXR within heterodimers, whereas offering multiple strategies for the assembly of the transcription complex.

  12. Dcp1 links coactivators of mRNA decapping to Dcp2 by proline recognition

    PubMed Central

    Borja, Mark S.; Piotukh, Kirill; Freund, Christian; Gross, John D.

    2011-01-01

    Cap hydrolysis is a critical step in several eukaryotic mRNA decay pathways and is carried out by the evolutionarily conserved decapping complex containing Dcp2 at the catalytic core. In yeast, Dcp1 is an essential activator of decapping and coactivators such as Edc1 and Edc2 are thought to enhance activity, though their mechanism remains elusive. Using kinetic analysis we show that a crucial function of Dcp1 is to couple the binding of coactivators of decapping to activation of Dcp2. Edc1 and Edc2 bind Dcp1 via its EVH1 proline recognition site and stimulate decapping by 1000-fold, affecting both the KM for mRNA and rate of the catalytic step. The C-terminus of Edc1 is necessary and sufficient to enhance the catalytic step, while the remainder of the protein likely increases mRNA binding to the decapping complex. Lesions in the Dcp1 EVH1 domain or the Edc1 proline-rich sequence are sufficient to block stimulation. These results identify a new role of Dcp1, which is to link the binding of coactivators to substrate recognition and activation of Dcp2. PMID:21148770

  13. Regulation of homocysteine homeostasis through the transcriptional coactivator PGC-1alpha.

    PubMed

    Li, Siming; Arning, Erland; Liu, Chang; Vitvitsky, Victor; Hernandez, Carlos; Banerjee, Ruma; Bottiglieri, Teodoro; Lin, Jiandie D

    2009-03-01

    Plasma homocysteine (Hcy) is an independent risk factor for cardiovascular disease. Hcy is a nonprotein amino acid derivative that is generated from the methionine cycle, which provides the methyl group for essentially all biological methylation reactions. Although plasma Hcy levels are elevated in patients with cardiovascular disease, the mechanisms that regulate Hcy homeostasis remain poorly defined. In this study, we found that the expression of key enzymes involved in Hcy metabolism is induced in the liver in response to fasting. This induction coincides with increased expression of peroxisome proliferator-activated receptor-gamma coactivator (PGC)-1alpha, a transcriptional coactivator that regulates hepatic gluconeogenesis and mitochondrial function. PGC-1alpha stimulates the expression of genes involved in Hcy metabolism in cultured primary hepatocytes as well as in the liver. Adenoviral-mediated expression of PGC-1alpha in vivo leads to elevated plasma Hcy levels. In contrast, mice deficient in PGC-1alpha have lower plasma Hcy concentrations. These results define a novel role for the PGC-1alpha coactivator pathway in the regulation of Hcy homeostasis and suggest a potential pathogenic mechanism that contributes to hyperhomocysteinemia.

  14. 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.

  15. 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…

  16. Recruitment of the transcriptional coactivator HCF-1 to viral immediate-early promoters during initiation of reactivation from latency of herpes simplex virus type 1.

    PubMed

    Whitlow, Zackary; Kristie, Thomas M

    2009-09-01

    The transcriptional coactivator host cell factor 1 (HCF-1) is critical for the expression of immediate-early (IE) genes of the alphaherpesviruses herpes simplex virus type 1 (HSV-1) and varicella-zoster virus. HCF-1 may also be involved in the reactivation of these viruses from latency as it is sequestered in the cytoplasm of sensory neurons but is rapidly relocalized to the nucleus upon stimulation that results in reactivation. Here, chromatin immunoprecipitation assays demonstrate that HCF-1 is recruited to IE promoters of viral genomes during the initiation of reactivation, correlating with RNA polymerase II occupancy and IE expression. The data support the model whereby HCF-1 plays a pivotal role in the reactivation of HSV-1 from latency.

  17. 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.

  18. Mechanistic studies on transcriptional coactivator protein arginine methyltransferase 1.

    PubMed

    Rust, Heather L; Zurita-Lopez, Cecilia I; Clarke, Steven; Thompson, Paul R

    2011-04-26

    Protein arginine methyltransferases (PRMTs) catalyze the transfer of methyl groups from S-adenosylmethionine (SAM) to the guanidinium group of arginine residues in a number of important cell signaling proteins. PRMT1 is the founding member of this family, and its activity appears to be dysregulated in heart disease and cancer. To begin to characterize the catalytic mechanism of this isozyme, we assessed the effects of mutating a number of highly conserved active site residues (i.e., Y39, R54, E100, E144, E153, M155, and H293), which are believed to play key roles in SAM recognition, substrate binding, and catalysis. The results of these studies, as well as pH-rate studies, and the determination of solvent isotope effects (SIEs) indicate that M155 plays a critical role in both SAM binding and the processivity of the reaction but is not responsible for the regiospecific formation of asymmetrically dimethylated arginine (ADMA). Additionally, mutagenesis studies on H293, combined with pH studies and the lack of a normal SIE, do not support a role for this residue as a general base. Furthermore, the lack of a normal SIE with either the wild type or catalytically impaired mutants suggests that general acid/base catalysis is not important for promoting methyl transfer. This result, combined with the fact that the E144A/E153A double mutant retains considerably more activity then the single mutants alone, suggests that the PRMT1-catalyzed reaction is primarily driven by bringing the substrate guanidinium into the proximity of the S-methyl group of SAM and that the prior deprotonation of the substrate guanidinium is not required for methyl transfer.

  19. Abnormal coactivation of knee and ankle extensors is related to changes in heteronymous spinal pathways after stroke

    PubMed Central

    2011-01-01

    Background Abnormal coactivation of leg extensors is often observed on the paretic side of stroke patients while they attempt to move. The mechanisms underlying this coactivation are not well understood. This study (1) compares the coactivation of leg extensors during static contractions in stroke and healthy individuals, and (2) assesses whether this coactivation is related to changes in intersegmental pathways between quadriceps and soleus (Sol) muscles after stroke. Methods Thirteen stroke patients and ten healthy individuals participated in the study. Levels of coactivation of knee extensors and ankle extensors were measured in sitting position, during two tasks: maximal isometric voluntary contractions in knee extension and in plantarflexion. The early facilitation and later inhibition of soleus voluntary EMG evoked by femoral nerve stimulation were assessed in the paretic leg of stroke participants and in one leg of healthy participants. Results Coactivation levels of ankle extensors (mean ± SEM: 56 ± 7% of Sol EMG max) and of knee extensors (52 ± 10% of vastus lateralis (VL) EMG max) during the knee extension and the ankle extension tasks respectively were significantly higher in the paretic leg of stroke participants than in healthy participants (26 ± 5% of Sol EMG max and 10 ± 3% of VL EMG max, respectively). Early heteronymous facilitation of Sol voluntary EMG in stroke participants (340 ± 62% of Sol unconditioned EMG) was significantly higher than in healthy participants (98 ± 34%). The later inhibition observed in all control participants was decreased in the paretic leg. Levels of coactivation of ankle extensors during the knee extension task were significantly correlated with both the increased facilitation (Pearson r = 0.59) and the reduced inhibition (r = 0.56) in the paretic leg. Measures of motor impairment were more consistently correlated with the levels of coactivation of biarticular muscles than those of monoarticular muscles

  20. Understanding Playful Pedagogies, Play Narratives and Play Spaces

    ERIC Educational Resources Information Center

    Goouch, Kathy

    2008-01-01

    This paper is a tentative attempt to unwrap and understand one aspect of playful practice and the influences which determine its existence in early years settings. "Storying" events, those occasions when teachers and children together "make up" stories or parts of stories, develop roles or co-construct fantasies, occur moment by moment in some…

  1. 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…

  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. Insights into Degron Recognition by APC/C Coactivators from the Structure of an Acm1-Cdh1 Complex

    PubMed Central

    He, Jun; Chao, William C.H.; Zhang, Ziguo; Yang, Jing; Cronin, Nora; Barford, David

    2013-01-01

    Summary The anaphase-promoting complex/cyclosome (APC/C) regulates sister chromatid segregation and the exit from mitosis. Selection of most APC/C substrates is controlled by coactivator subunits (either Cdc20 or Cdh1) that interact with substrate destruction motifs—predominantly the destruction (D) box and KEN box degrons. How coactivators recognize D box degrons and how this is inhibited by APC/C regulatory proteins is not defined at the atomic level. Here, from the crystal structure of S. cerevisiae Cdh1 in complex with its specific inhibitor Acm1, which incorporates D and KEN box pseudosubstrate motifs, we describe the molecular basis for D box recognition. Additional interactions between Acm1 and Cdh1 identify a third protein-binding site on Cdh1 that is likely to confer coactivator-specific protein functions including substrate association. We provide a structural rationalization for D box and KEN box recognition by coactivators and demonstrate that many noncanonical APC/C degrons bind APC/C coactivators at the D box coreceptor. PMID:23707760

  4. Distinct roles of the steroid receptor coactivator 1 and of MED1 in retinoid-induced transcription and cellular differentiation.

    PubMed

    Flajollet, Sébastien; Lefebvre, Bruno; Rachez, Christophe; Lefebvre, Philippe

    2006-07-21

    Retinoic acid receptors (RARs) are the molecular relays of retinoid action on transcription, cellular differentiation and apoptosis. Transcriptional activation of retinoid-regulated promoters requires the dismissal of corepressors and the recruitment of coactivators to promoter-bound RAR. RARs recruit in vitro a plethora of coactivators whose actual contribution to retinoid-induced transcription is poorly characterized in vivo. Embryonal carcinoma P19 cells, which are highly sensitive to retinoids, were depleted from archetypical coactivators by RNAi. SRC1-deficient P19 cells showed severely compromised retinoid-induced responses, in agreement with the supposed role of SRC1 as a RAR coactivator. Unexpectedly, Med1/TRAP220/DRIP205-depleted cells exhibited an exacerbated response to retinoids, both in terms transcriptional responses and of cellular differentiation. Med1 depletion affected TFIIH and cdk9 detection at the prototypical retinoid-regulated RARbeta2 promoter, and favored a higher RNA polymerase II detection in transcribed regions of the RARbeta2 gene. Furthermore, the nature of the ligand impacted strongly on the ability of RARs to interact with a given coactivator and to activate transcription in intact cells. Thus RAR accomplishes transcriptional activation as a function of the ligand structure, by recruiting regulatory complexes which control distinct molecular events at retinoid-regulated promoters.

  5. 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)

  6. 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

  7. CIA, a novel estrogen receptor coactivator with a bifunctional nuclear receptor interacting determinant.

    PubMed

    Sauvé, F; McBroom, L D; Gallant, J; Moraitis, A N; Labrie, F; Giguère, V

    2001-01-01

    Coregulators for nuclear receptors (NR) are factors that either enhance or repress their transcriptional activity. Both coactivators and corepressors have been shown to use similar but functionally distinct NR interacting determinants containing the core motifs LxxLL and PhixxPhiPhi, respectively. These interactions occur through a hydrophobic cleft located on the surface of the ligand-binding domain (LBD) of the NR and are regulated by ligand-dependent activation function 2 (AF-2). In an effort to identify novel coregulators that function independently of AF-2, we used the LBD of the orphan receptor RVR (which lacks AF-2) as bait in a yeast two-hybrid screen. This strategy led to the cloning of a nuclear protein referred to as CIA (coactivator independent of AF-2 function) that possesses both repressor and activator functions. Strikingly, we observed that CIA not only interacts with RVR and Rev-ErbAalpha in a ligand-independent manner but can also form complexes with estrogen receptor alpha (ERalpha) and ERbeta in vitro and enhances ERalpha transcriptional activity in the presence of estradiol (E(2)). CIA-ERalpha interactions were found to be independent of AF-2 and enhanced by the antiestrogens EM-652 and ICI 182,780 but not by 4-hydroxytamoxifen and raloxifene. We further demonstrate that CIA-ERalpha interactions require the presence within CIA of a novel bifunctional NR recognition determinant containing overlapping LxxLL and PhixxPhiPhi motifs. The identification and functional characterization of CIA suggest that hormone binding can create a functional coactivator interaction interface in the absence of AF-2.

  8. The Excellence of Play.

    ERIC Educational Resources Information Center

    Moyles, Janet R., Ed.

    Recognizing that for young children, play is a tool for learning, this book compiles contributions by different authors, reflecting both up-to-date research and current classroom practice as they relate to children's play. Part 1 of the book explores the value of play as a cross-cultural concept as well as one rooted in the Western world. Gender…

  9. 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…

  10. Dimensions of Infant Play.

    ERIC Educational Resources Information Center

    Fenson, Larry

    Changes in manipulative play with objects were examined in a longitudinal sample of 10 boys and 9 girls tested at ages 9, 13, and 18 months. Stability of individual differences in play was also examined. Each child was observed individually for 7 minutes in a room in which a tea set was the only toy present. Seven types of play behavior were…

  11. 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…

  12. The Importance of Play.

    ERIC Educational Resources Information Center

    Sher, Allen

    Play is the spontaneous or organized recreational activity of children; it is at the heart of the preschool curriculum. Play aids in the development of physical, intellectual, and social skills. Children's play progresses through three developmental stages: solitary, parallel, and social. Preschool teachers should arrange for four kinds of…

  13. Literacy through Play.

    ERIC Educational Resources Information Center

    Owocki, Gretchen

    When young children play in a purposefully designed, literacy-rich environment, teachers can discover and capitalize on teachable moments. This book discusses how children develop literacy and how early childhood teachers use play and other child-centered experiences to facilitate literacy development. Chapter 1, "Play and Developmentally…

  14. 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…

  15. 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

  16. 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.

  17. 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

  18. 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

  19. von Hippel-Lindau partner Jade-1 is a transcriptional co-activator associated with histone acetyltransferase activity.

    PubMed

    Panchenko, Maria V; Zhou, Mina I; Cohen, Herbert T

    2004-12-31

    Jade-1 was identified as a protein partner of the von Hippel-Lindau tumor suppressor pVHL. The interaction of Jade-1 and pVHL correlates with renal cancer risk. We have investigated the molecular function of Jade-1. Jade-1 has two zinc finger motifs called plant homeodomains (PHD). A line of evidence suggests that the PHD finger functions in chromatin remodeling and protein-protein interactions. We determined the cellular localization of Jade-1 and examined whether Jade-1 might have transcriptional and histone acetyltransferase (HAT) functions. Biochemical cell fractionation studies as well as confocal images of cells immunostained with a specific Jade-1 antibody revealed that endogenous Jade-1 is localized predominantly in the cell nucleus. Tethering of Gal4-Jade-1 fusion protein to Gal4-responsive promoters in co-transfection experiments activated transcription 5-6-fold, indicating that Jade-1 is a possible transcriptional activator. It was remarkable that overexpression of Jade-1 in cultured cells specifically increased levels of endogenous acetylated histone H4, but not histone H3, strongly suggesting that Jade-1 associates with HAT activity specific for histone H4. Deletion of the two PHD fingers completely abolished Jade-1 transcriptional and HAT activities, indicating that these domains are indispensable for Jade-1 nuclear functions. In addition, we demonstrated that TIP60, a known HAT with histone H4/H2A specificity, physically associates with Jade-1 and is able to augment Jade-1 HAT function in live cells, strongly suggesting that TIP60 might mediate Jade-1 HAT activity. Thus, Jade-1 is a novel candidate transcriptional co-activator associated with HAT activity and may play a key role in the pathogenesis of renal cancer and von Hippel-Lindau disease.

  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. 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…

  2. Steroid receptor coactivators 1, 2, and 3: critical regulators of nuclear receptor activity and steroid receptor modulator (SRM)-based cancer therapy.

    PubMed

    Johnson, Amber B; O'Malley, Bert W

    2012-01-30

    Coactivators are a diverse group of non-DNA binding proteins that induce structural changes in agonist-bound nuclear receptors (NRs) that are essential for NR-mediated transcriptional activation. Once bound, coactivators function to bridge enhancer binding proteins to the general transcription machinery, as well as to recruit secondary coactivators that modify promoter and enhancer chromatin in a manner permissive for transcriptional activation. In the following review article, we focus on one of the most in-depth studied families of coactivators, the steroid receptor coactivators (SRC) 1, 2, and 3. SRCs are widely implicated in NR-mediated diseases, especially in cancers, with the majority of studies focused on their roles in breast cancer. We highlight the relevant literature supporting the oncogenic activity of SRCs and their future as diagnostic and prognostic indicators. With much interest in the development of selective receptor modulators (SRMs), we focus on how these coactivators regulate the interactions between SRMs and their respective NRs; and, importantly, the influence that coactivators have on the functional output of SRMs. Furthermore, we speculate that coactivator-specific inhibitors could provide powerful, all-encompassing treatments that target multiple modes of oncogenic regulation in cancers resistant to typical anti-endocrine treatments.

  3. Steroid Receptor Coactivators 1, 2, and 3: Critical Regulators of Nuclear Receptor Activity and Steroid Receptor Modulator (SRM)-based Cancer Therapy

    PubMed Central

    Johnson, Amber B.; O’Malley, Bert W.

    2011-01-01

    Coactivators are a diverse group of non-DNA binding proteins that induce structural changes in agonist-bound nuclear receptors (NRs) that are essential for NR-mediated transcriptional activation. Once bound, coactivators function to bridge enhancer binding proteins to the general transcription machinery, as well as to recruit secondary coactivators that modify promoter and enhancer chromatin in a manner permissive for transcriptional activation. In the following review article, we focus on one of the most in-depth studied families of coactivators, the steroid receptor coactivators (SRC) 1, 2, and 3. SRCs are widely implicated in NR-mediated diseases, especially in cancers, with the majority of studies focused on their roles in breast cancer. We highlight the relevant literature supporting the oncogenic activity of SRCs and their future as diagnostic and prognostic indicators. With much interest in the development of selective receptor modulators (SRMs), we focus on how these coactivators regulate the interactions between SRMs and their respective NRs; and, importantly, the influence that coactivators have on the functional output of SRMs. Furthermore, we speculate that coactivator-specific inhibitors could provide powerful, all-encompassing treatments that target multiple modes of oncogenic regulation in cancers resistant to typical anti-endocrine treatments. PMID:21664237

  4. Transactivation and Coactivator Recruitment Assays for Measuring Farnesoid X Receptor Activity.

    PubMed

    Hsu, Chia-Wen Amy; Zhao, Jinghua; Xia, Menghang

    2016-01-01

    The farnesoid X receptor (FXR) is a nuclear receptor responsible for homeostasis of bile acids, lipids, and glucose. Compounds that alter endogenous FXR signaling can be used as therapeutic candidates or identified as potentially hazardous compounds depending on exposure doses and health states. Therefore, there is an increasing need for high-throughput screening assays of FXR activity to profile large numbers of environmental chemicals and drugs. This chapter describes a workflow of FXR modulator identification and characterization. To identify compounds that modulate FXR transactivation at the cellular level, we first screen compounds from the Tox21 10 K compound library in an FXR-driven beta-lactamase reporter gene assay multiplexed with a cell viability assay in the same well of the 1536-well plates. The selected compounds are then tested biochemically for their ability to modulate FXR-coactivator binding interactions using a time-resolved fluorescence resonance energy transfer (TR-FRET) coactivator assay. The assay results from the workflow can be used to prioritize compounds for more extensive investigations. PMID:27518622

  5. 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.

  6. Sam68 functions as a transcriptional coactivator of the p53 tumor suppressor

    PubMed Central

    Li, Naomi; Richard, Stéphane

    2016-01-01

    Sam68 is a known sequence-specific RNA binding protein that regulates alternative splicing events during the cell cycle and apoptosis. Sam68 has also been shown to influence transcription, but the molecular mechanism remains undefined. Herein we identify Sam68 as a transcriptional coactivator of the p53 tumor suppressor in response to DNA damage. Using CRISPR/Cas9 generated isogenic HCT116 Sam68−/− cell lines wild type or deficient for p53, we show that Sam68 is required for the efficient transactivation of p53 target genes. Consistently, Sam68 depletion caused defects in DNA damage-induced cell cycle arrest and apoptosis mediated by p53. Mechanistically, we demonstrate that Sam68 physically interacted with p53 in an RNA-dependent manner, and that this interaction was essential for the coactivator function of Sam68. Furthermore, we show that both Sam68 and p53 were recruited to promoters of p53-responsive genes, suggesting interdependence. Finally, Sam68 acted in concert with the p53 long noncoding RNA (lncRNA) target PR-lncRNA-1 for p53 recruitment, implicating a positive-feedback mechanism in which lncRNAs induced by the Sam68/p53 complex can enhance p53 transcriptional activity. These findings define a hitherto novel mechanism of action for Sam68 in governing p53 transcriptional activation, and represent the first report of Sam68 in the regulation of tumor suppressor activities. PMID:27365047

  7. Co-activated yet disconnected-Neural correlates of eye closures when trying to stay awake.

    PubMed

    Ong, Ju Lynn; Kong, Danyang; Chia, Tiffany T Y; Tandi, Jesisca; Thomas Yeo, B T; Chee, Michael W L

    2015-09-01

    Spontaneous eye-closures that herald sleep onset become more frequent when we are sleep deprived. Although these are typically associated with decreased responsiveness to external stimuli, it is less clear what occurs in the brain at these transitions to drowsiness and light sleep. To investigate this, task-free fMRI of sleep-deprived participants was acquired. BOLD activity associated with periods of spontaneously occurring eye closures were marked and analyzed. We observed concurrent and extensive hypnagogic co-activation of the extrastriate visual, auditory, and somatosensory cortices as well as the default mode network, consistent with internal sensory activity without external stimulation. Co-activation of fronto-parietal areas known to mediate attentional control could correspond with participants resisting sleep or additional engagement of mental imagery. This constellation of signal changes differed from those elicited by cued eye closures of similar duration and distribution in the same, rested participants. They also differ from signal changes associated with mind-wandering and consolidated light sleep. Concurrent with the observed event-related changes, eye closures elicited additional reduction in functional connectivity within nodes of the DMN and DAN, superposed on already reduced connectivity associated with sleep deprivation. There was concurrent deactivation of the thalamus during eye-closure during the sleep-deprived state but almost similar changes occurred in the well-rested state that may also be relevant. These findings highlight the dynamic shifts in brain activity and connectivity at border between wakefulness and sleep.

  8. 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

  9. The X protein of hepatitis B virus coactivates potent activation domains.

    PubMed Central

    Haviv, I; Vaizel, D; Shaul, Y

    1995-01-01

    Transactivation by hepatitis B virus X protein (pX) is promiscuous, but it requires cellular activators. To study the mode of action of pX, we coexpressed pX with Gal4-derived activators in a cotransfection system. Twelve different activators bearing different types of activation domains were compared for their response to pX. Because pX indirectly increases the amount of the activators, tools were developed to compare samples with equivalent amount of activators. We demonstrate that pX preferentially coactivates potent activators, especially those with acidic activation domains. Weak activators with nonacidic activation domains are not potentiated by pX. Interestingly, Gal4E1a, which is not rich in acidic residues but interacts with similar molecular targets, also responds to pX. The response to pX correlated with the strength of the activation domain. Collectively, these data imply that pX is a coactivator, which offers a molecular basis for the pleiotropic effects of pX on transcription. PMID:7823923

  10. Transcriptional activity of Pax3 is co-activated by TAZ

    SciTech Connect

    Murakami, Masao; Tominaga, Junji; Makita, Ryosuke; Uchijima, Yasunobu; Kurihara, Yukiko; Nakagawa, Osamu; Asano, Tomoichiro; Kurihara, Hiroki . E-mail: kuri-tky@umin.ac.jp

    2006-01-13

    Pax3 is a transcription factor which functions in embryonic development and human diseases. In a yeast two-hybrid screen with full-length Pax3 as bait, we isolated a clone encoding transcriptional co-activator with PDZ-binding motif (TAZ) from an E10.5 mouse embryo cDNA library. Co-immunoprecipitation and nuclear co-localization of TAZ with Pax3 suggest that their association is functionally relevant. In situ hybridization revealed TAZ and Pax3 expression to partially overlap in the paraxial mesoderm, limb buds, and the neural tube. In C2C12 myoblast cells and NIH3T3 cells, TAZ enhanced the transcriptional activity of Pax3 on artificial and microphthalmia-associated transcription factor promoter-luciferase constructs, suggesting that TAZ can function as a co-activator of Pax3. Functional interaction between Pax3 and TAZ may provide a clue to clarifying the mechanism by which Pax3 serves as a transcriptional activator during embryogenesis.

  11. Identifying Functional Co-activation Patterns in Neuroimaging Studies via Poisson Graphical Models

    PubMed Central

    Xue, Wenqiong; Kang, Jian; Bowman, F. DuBois; Wager, Tor D.; Guo, Jian

    2014-01-01

    Summary Studying the interactions between different brain regions is essential to achieve a more complete understanding of brain function. In this paper, we focus on identifying functional co-activation patterns and undirected functional networks in neuroimaging studies. We build a functional brain network, using a sparse covariance matrix, with elements representing associations between region-level peak activations. We adopt a penalized likelihood approach to impose sparsity on the covariance matrix based on an extended multivariate Poisson model. We obtain penalized maximum likelihood estimates via the expectation-maximization (EM) algorithm and optimize an associated tuning parameter by maximizing the predictive log-likelihood. Permutation tests on the brain co-activation patterns provide region pair and network-level inference. Simulations suggest that the proposed approach has minimal biases and provides a coverage rate close to 95% of covariance estimations. Conducting a meta-analysis of 162 functional neuroimaging studies on emotions, our model identifies a functional network that consists of connected regions within the basal ganglia, limbic system, and other emotion-related brain regions. We characterize this network through statistical inference on region-pair connections as well as by graph measures. PMID:25147001

  12. 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

  13. Transactivation and Coactivator Recruitment Assays for Measuring Farnesoid X Receptor Activity.

    PubMed

    Hsu, Chia-Wen Amy; Zhao, Jinghua; Xia, Menghang

    2016-01-01

    The farnesoid X receptor (FXR) is a nuclear receptor responsible for homeostasis of bile acids, lipids, and glucose. Compounds that alter endogenous FXR signaling can be used as therapeutic candidates or identified as potentially hazardous compounds depending on exposure doses and health states. Therefore, there is an increasing need for high-throughput screening assays of FXR activity to profile large numbers of environmental chemicals and drugs. This chapter describes a workflow of FXR modulator identification and characterization. To identify compounds that modulate FXR transactivation at the cellular level, we first screen compounds from the Tox21 10 K compound library in an FXR-driven beta-lactamase reporter gene assay multiplexed with a cell viability assay in the same well of the 1536-well plates. The selected compounds are then tested biochemically for their ability to modulate FXR-coactivator binding interactions using a time-resolved fluorescence resonance energy transfer (TR-FRET) coactivator assay. The assay results from the workflow can be used to prioritize compounds for more extensive investigations.

  14. 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.

  15. Steroid Receptor Coactivator-2 Is a Dual Regulator of Cardiac Transcription Factor Function*

    PubMed Central

    Reineke, Erin L.; Benham, Ashley; Soibam, Benjamin; Stashi, Erin; Taegtmeyer, Heinrich; Entman, Mark L.; Schwartz, Robert J.; O'Malley, Bert W.

    2014-01-01

    We have previously demonstrated the potential role of steroid receptor coactivator-2 (SRC-2) as a co-regulator in the transcription of critical molecules modulating cardiac function and metabolism in normal and stressed hearts. The present study seeks to extend the previous information by demonstrating SRC-2 fulfills this role by serving as a critical coactivator for the transcription and activity of critical transcription factors known to control cardiac growth and metabolism as well as in their downstream signaling. This knowledge broadens our understanding of the mechanism by which SRC-2 acts in normal and stressed hearts and allows further investigation of the transcriptional modifications mediating different types and degrees of cardiac stress. Moreover, the genetic manipulation of SRC-2 in this study is specific for the heart and thereby eliminating potential indirect effects of SRC-2 deletion in other organs. We have shown that SRC-2 is critical to transcriptional control modulated by MEF2, GATA-4, and Tbx5, thereby enhancing gene expression associated with cardiac growth. Additionally, we describe SRC-2 as a novel regulator of PPARα expression, thus controlling critical steps in metabolic gene expression. We conclude that through regulation of cardiac transcription factor expression and activity, SRC-2 is a critical transcriptional regulator of genes important for cardiac growth, structure, and metabolism, three of the main pathways altered during the cardiac stress response. PMID:24811170

  16. Steroid receptor coactivator-2 is a dual regulator of cardiac transcription factor function.

    PubMed

    Reineke, Erin L; Benham, Ashley; Soibam, Benjamin; Stashi, Erin; Taegtmeyer, Heinrich; Entman, Mark L; Schwartz, Robert J; O'Malley, Bert W

    2014-06-20

    We have previously demonstrated the potential role of steroid receptor coactivator-2 (SRC-2) as a co-regulator in the transcription of critical molecules modulating cardiac function and metabolism in normal and stressed hearts. The present study seeks to extend the previous information by demonstrating SRC-2 fulfills this role by serving as a critical coactivator for the transcription and activity of critical transcription factors known to control cardiac growth and metabolism as well as in their downstream signaling. This knowledge broadens our understanding of the mechanism by which SRC-2 acts in normal and stressed hearts and allows further investigation of the transcriptional modifications mediating different types and degrees of cardiac stress. Moreover, the genetic manipulation of SRC-2 in this study is specific for the heart and thereby eliminating potential indirect effects of SRC-2 deletion in other organs. We have shown that SRC-2 is critical to transcriptional control modulated by MEF2, GATA-4, and Tbx5, thereby enhancing gene expression associated with cardiac growth. Additionally, we describe SRC-2 as a novel regulator of PPARα expression, thus controlling critical steps in metabolic gene expression. We conclude that through regulation of cardiac transcription factor expression and activity, SRC-2 is a critical transcriptional regulator of genes important for cardiac growth, structure, and metabolism, three of the main pathways altered during the cardiac stress response. PMID:24811170

  17. Cloning, genomic organization, and expression analysis of zebrafish nuclear receptor coactivator, TIF2.

    PubMed

    Tan, Jee-Hian; Quek, Sue-Ing; Chan, Woon-Khiong

    2005-01-01

    Thyroid hormone receptors (TRs) are involved in numerous diverse biological processes such as growth and differentiation, thermogenesis, neurulation, homeostasis, and metamorphosis. In zebrafish, TRbeta1 has been implicated to be involved in the obligatory embryonic-to-larval transitory phase. In order to understand if nuclear receptor coactivators could modulate the transcriptional activities of TRs during this transitory phase, the transcriptionary intermediary factor 2 (TIF2), a member of the p160 coactivator, was isolated from zebrafish. The zebrafish tif2 cDNA encodes a polypeptide of 1,505 amino acids. The tif2 gene is made up of 23 exons with the AUG and stop codon located in Exon IV and XXIII, respectively. The overall genomic organization of human and zebrafish tif2 genes are very similar. Four tif2 isoforms were identified by RT-PCR. The N-terminus mRNA variants are generated as a result of multiple initiation start sites located upstream of the noncoding Exon I and Exon II. The C-terminus isoforms, E20a and E20b, resulted from the alternative splicing of Exon XX. Although E20a and E20b isoforms were ubiquitously expressed, they were very highly expressed in reproductive tissues. The availability of TIF2 cDNA will allow the analysis of its functional roles in mediating the actions of TRs in various aspects of zebrafish developmental biology.

  18. 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

  19. 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

  20. Ubiquitin-dependent distribution of the transcriptional coactivator p300 in cytoplasmic inclusion bodies.

    PubMed

    Chen, Jihong; Halappanavar, Sabina; Th' ng, John P H; Li, Qiao

    2007-01-01

    The protein level of transcriptional coactivator p300, an essential nuclear protein, is critical to a broad array of cellular activities including embryonic development, cell differentiation and proliferation. We have previously established that histone deacetylase inhibitor such as valproic acid induces p300 degradation through the 26S proteasome pathway. Here, we report the roles of cellular trafficking and spatial redistribution in valproic acid-induced p300 turnover. Our study demonstrates that p300 is redistributed to the cytoplasm prior to valproic acid-induced turnover. Inhibition of proteasome-dependent protein degradation, does not prevent nucleo-cytoplasmic shuttling of p300, rather sequesters the cytoplasmic p300 to a distinct perinuclear region. In addition, the formation of p300 aggregates in the perinuclear region depends on functional microtubule networks and correlates with p300 ubiquitination. Our work establishes, for the first time, that p300 is also a substrate of the cytoplasmic ubiquitin-proteasome system and provides insight on how cellular trafficking and spatial redistribution regulate the availability and activity of transcriptional coactivator p300.

  1. The transcriptional coactivator PGC-1alpha mediates exercise-induced angiogenesis in skeletal muscle.

    PubMed

    Chinsomboon, Jessica; Ruas, Jorge; Gupta, Rana K; Thom, Robyn; Shoag, Jonathan; Rowe, Glenn C; Sawada, Naoki; Raghuram, Srilatha; Arany, Zoltan

    2009-12-15

    Peripheral arterial disease (PAD) affects 5 million people in the US and is the primary cause of limb amputations. Exercise remains the single best intervention for PAD, in part thought to be mediated by increases in capillary density. How exercise triggers angiogenesis is not known. PPARgamma coactivator (PGC)-1alpha is a potent transcriptional co-activator that regulates oxidative metabolism in a variety of tissues. We show here that PGC-1alpha mediates exercise-induced angiogenesis. Voluntary exercise induced robust angiogenesis in mouse skeletal muscle. Mice lacking PGC-1alpha in skeletal muscle failed to increase capillary density in response to exercise. Exercise strongly induced expression of PGC-1alpha from an alternate promoter. The induction of PGC-1alpha depended on beta-adrenergic signaling. beta-adrenergic stimulation also induced a broad program of angiogenic factors, including vascular endothelial growth factor (VEGF). This induction required PGC-1alpha. The orphan nuclear receptor ERRalpha mediated the induction of VEGF by PGC-1alpha, and mice lacking ERRalpha also failed to increase vascular density after exercise. These data demonstrate that beta-adrenergic stimulation of a PGC-1alpha/ERRalpha/VEGF axis mediates exercise-induced angiogenesis in skeletal muscle.

  2. Sumoylation of poly(ADP-ribose) polymerase 1 inhibits its acetylation and restrains transcriptional coactivator function.

    PubMed

    Messner, Simon; Schuermann, David; Altmeyer, Matthias; Kassner, Ingrid; Schmidt, Darja; Schär, Primo; Müller, Stefan; Hottiger, Michael O

    2009-11-01

    Poly(ADP-ribose) polymerase 1 (PARP1) is a chromatin-associated nuclear protein and functions as a molecular stress sensor. At the cellular level, PARP1 has been implicated in a wide range of processes, such as maintenance of genome stability, cell death, and transcription. PARP1 functions as a transcriptional coactivator of nuclear factor kappaB (NF-kappaB) and hypoxia inducible factor 1 (HIF1). In proteomic studies, PARP1 was found to be modified by small ubiquitin-like modifiers (SUMOs). Here, we characterize PARP1 as a substrate for modification by SUMO1 and SUMO3, both in vitro and in vivo. PARP1 is sumoylated at the single lysine residue K486 within its automodification domain. Interestingly, modification of PARP1 with SUMO does not affect its ADP-ribosylation activity but completely abrogates p300-mediated acetylation of PARP1, revealing an intriguing crosstalk of sumoylation and acetylation on PARP1. Genetic complementation of PARP1-depleted cells with wild-type and sumoylation-deficient PARP1 revealed that SUMO modification of PARP1 restrains its transcriptional coactivator function and subsequently reduces gene expression of distinct PARP1-regulated target genes.

  3. Circadian metabolic regulation through crosstalk between casein kinase 1δ and transcriptional coactivator PGC-1α.

    PubMed

    Li, Siming; Chen, Xiao-Wei; Yu, Lei; Saltiel, Alan R; Lin, Jiandie D

    2011-12-01

    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.

  4. Activation of TORC1 transcriptional coactivator through MEKK1-induced phosphorylation.

    PubMed

    Siu, Yeung-Tung; Ching, Yick-Pang; Jin, Dong-Yan

    2008-11-01

    CREB is a prototypic bZIP transcription factor and a master regulator of glucose metabolism, synaptic plasticity, cell growth, apoptosis, and tumorigenesis. Transducers of regulated CREB activity (TORCs) are essential transcriptional coactivators of CREB and an important point of regulation on which various signals converge. In this study, we report on the activation of TORC1 through MEKK1-mediated phosphorylation. MEKK1 potently activated TORC1, and this activation was independent of downstream effectors MEK1/MEK2, ERK2, JNK, p38, protein kinase A, and calcineurin. MEKK1 induced phosphorylation of TORC1 both in vivo and in vitro. Expression of the catalytic domain of MEKK1 alone in cultured mammalian cells sufficiently caused phosphorylation and subsequent activation of TORC1. MEKK1 physically interacted with TORC1 and stimulated its nuclear translocation. An activation domain responsive to MEKK1 stimulation was mapped to amino acids 431-650 of TORC1. As a physiological activator of CREB, interleukin 1alpha triggered MEKK1-dependent phosphorylation of TORC1 and its consequent recruitment to the cAMP response elements in the interleukin 8 promoter. Taken together, our findings suggest a new mechanism for regulated activation of TORC1 transcriptional coactivator and CREB signaling.

  5. Novel CARM1-Interacting Protein, DZIP3, Is a Transcriptional Coactivator of Estrogen Receptor-α.

    PubMed

    Purcell, Daniel J; Chauhan, Swati; Jimenez-Stinson, Diane; Elliott, Kathleen R; Tsewang, Tenzin D; Lee, Young-Ho; Marples, Brian; Lee, David Y

    2015-12-01

    Coactivator-associated arginine methyltransferase 1 (CARM1) is known to promote estrogen receptor (ER)α-mediated transcription in breast cancer cells. To further characterize the regulation of ERα-mediated transcription by CARM1, we screened CARM1-interacting proteins by yeast two-hybrid. Here, we have identified an E3 ubiquitin ligase, DAZ (deleted in azoospermia)-interacting protein 3 (DZIP3), as a novel CARM1-binding protein. DZIP3-dependent ubiquitination of histone H2A has been associated with repression of transcription. However, ERα reporter gene assays demonstrated that DZIP3 enhanced ERα-mediated transcription and cooperated synergistically with CARM1. Interaction with CARM1 was observed with the E3 ligase RING domain of DZIP3. The methyltransferase activity of CARM1 partially contributed to the synergy with DZIP3 for transcription activation, but the E3 ubiquitin ligase activity of DZIP3 was dispensable. DZIP3 also interacted with the C-terminal activation domain 2 of glucocorticoid receptor-interacting protein 1 (GRIP1) and enhanced the interaction between GRIP1 and CARM1. Depletion of DZIP3 by small interfering RNA in MCF7 cells reduced estradiol-induced gene expression of ERα target genes, GREB1 and pS2, and DZIP3 was recruited to the estrogen response elements of the same ERα target genes. These results indicate that DZIP3 is a novel coactivator of ERα target gene expression.

  6. 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

  7. 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…

  8. 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…

  9. Play, Toys and Television.

    ERIC Educational Resources Information Center

    Brougere, Gilles

    In Western societies, television has transformed the life, culture, and points of reference of the child. Its particular sphere of influence is the child's play culture. This play culture is not hermetic: it is very oriented toward manipulation; has a symbolic role as a representational medium; evolves along with the child; has a certain amount of…

  10. An Invitation to Play.

    ERIC Educational Resources Information Center

    Lange, Jenny; Zieher, Connie

    The manual is intended to provide suggestions for play to parents of young children with exceptional educational needs. Nineteen types of activities are described and pictured, including make believe with boxes, dress-up activities, kitchen play, bubbles, small motor activities using beans and buttons, use of throw-away materials, painting,…

  11. 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…

  12. 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)

  13. 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.

  14. 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,…

  15. 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…

  16. Theories of Play.

    ERIC Educational Resources Information Center

    Peller, Lili E.

    1996-01-01

    Discusses several theories of play advanced before the development of psychoanalysis, including the theories of surplus energy, recreation, and practice. Examines the psychoanalytical view advanced by Freud and others, which focuses on the emotional release of play and its role in discovery and learning. (MDM)

  17. Why People Play.

    ERIC Educational Resources Information Center

    Ellis, M. J.

    A critical analysis is made of the content and assumptions of the many theories or explanations for play behavior. The seven chapters of the book are as follows. Chapter One, A Purview of the Problems, is a brief overview of the problems inherent in attempting to manage play, and the arguments for and against. The second chapter, Definitions of…

  18. 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…

  19. 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…

  20. 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…

  1. 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…

  2. TATA-binding protein-free TAF-containing complex (TFTC) and p300 are both required for efficient transcriptional activation.

    PubMed

    Hardy, Sara; Brand, Marjorie; Mittler, Gerhard; Yanagisawa, Jun; Kato, Shigeaki; Meisterernst, Michael; Tora, Làszlò

    2002-09-01

    Initiation of transcription of protein-encoding genes by RNA polymerase II was thought to require transcription factor TFIID, a complex comprising the TATA-binding protein (TBP) and TBP-associated factors (TAFs). In the presence of TBP-free TAF complex (TFTC), initiation of polymerase II transcription can occur in the absence of TFIID. TFTC contains several subunits that have been shown to play the role of transcriptional coactivators, including the GCN5 histone acetyltransferase (HAT), which acetylates histone H3 in a nucleosomal context. Here we analyze the coactivator function of TFTC. We show direct physical interactions between TFTC and the two distinct activation regions (H1 and H2) of the VP16 activation domain, whereas the HAT-containing coactivators, p300/CBP (CREB-binding protein), interact only with the H2 subdomain of VP16. Accordingly, cell transfection experiments demonstrate the requirement of both p300 and TFTC for maximal transcriptional activation by GAL-VP16. In agreement with this finding, we show that in vitro on a chromatinized template human TFTC mediates the transcriptional activity of the VP16 activation domain in concert with p300 and in an acetyl-CoA-dependent manner. Thus, our results suggest that these two HAT-containing co-activators, p300 and TFTC, have complementary rather than redundant roles during the transcriptional activation process. PMID:12107188

  3. Site-specific proteolysis of the transcriptional coactivator HCF-1 can regulate its interaction with protein cofactors.

    PubMed

    Vogel, Jodi L; Kristie, Thomas M

    2006-05-01

    Limited proteolytic processing is an important transcriptional regulatory mechanism. In various contexts, proteolysis controls the cytoplasmic-to-nuclear transport of important transcription factors or removes domains to produce factors with altered activities. The transcriptional coactivator host cell factor-1 (HCF-1) is proteolytically processed within a unique domain consisting of 20-aa reiterations. Site-specific cleavage within one or more repeats generates a family of amino- and carboxyl-terminal subunits that remain tightly associated. However, the consequences of HCF-1 processing have been undefined. In this study, it was determined that the HCF-1-processing domain interacts with several proteins including the transcriptional coactivator/corepressor four-and-a-half LIM domain-2 (FHL2). Analysis of this interaction has uncovered specificity with both sequence and context determinants within the reiterations of this processing domain. In cells, FHL2 interacts exclusively with the nonprocessed coactivator and costimulates transcription of an HCF-1-dependent target gene. The functional interaction of HCF-1 with FHL2 supports a model in which site-specific proteolysis regulates the interaction of HCF-1 with protein partners and thus can modulate the activity of this coactivator. This paradigm expands the biological significance of limited proteolytic processing as a regulatory mechanism in gene transcription.

  4. 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)

  5. 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)

  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. Ash2 acts as an ecdysone receptor coactivator by stabilizing the histone methyltransferase Trr.

    PubMed

    Carbonell, Albert; Mazo, Alexander; Serras, Florenci; Corominas, Montserrat

    2013-02-01

    The molting hormone ecdysone triggers chromatin changes via histone modifications that are important for gene regulation. On hormone activation, the ecdysone receptor (EcR) binds to the SET domain-containing histone H3 methyltransferase trithorax-related protein (Trr). Methylation of histone H3 at lysine 4 (H3K4me), which is associated with transcriptional activation, requires several cofactors, including Ash2. We find that ash2 mutants have severe defects in pupariation and metamorphosis due to a lack of activation of ecdysone-responsive genes. This transcriptional defect is caused by the absence of the H3K4me3 marks set by Trr in these genes. We present evidence that Ash2 interacts with Trr and is required for its stabilization. Thus we propose that Ash2 functions together with Trr as an ecdysone receptor coactivator.

  8. Simultaneous blind separation and clustering of coactivated EEG/MEG sources for analyzing spontaneous brain activity.

    PubMed

    Hirayama, Jun-ichiro; Ogawa, Takeshi; Hyvärinen, Aapo

    2014-01-01

    Analysis of the dynamics (non-stationarity) of functional connectivity patterns has recently received a lot of attention in the neuroimaging community. Most analysis has been using functional magnetic resonance imaging (fMRI), partly due to the inherent technical complexity of the electro- or magnetoencephalography (EEG/MEG) signals, but EEG/MEG holds great promise in analyzing fast changes in connectivity. Here, we propose a method for dynamic connectivity analysis of EEG/MEG, combining blind source separation with dynamic connectivity analysis in a single probabilistic model. Blind source separation is extremely useful for interpretation of the connectivity changes, and also enables rejection of artifacts. Dynamic connectivity analysis is performed by clustering the coactivation patterns of separated sources by modeling their variances. Experiments on resting-state EEG show that the obtained clusters correlate with physiologically meaningful quantities. PMID:25571098

  9. 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

  10. 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

  11. Human transcriptional coactivator PC4 stimulates DNA end joining and activates DSB repair activity.

    PubMed

    Batta, Kiran; Yokokawa, Masatoshi; Takeyasu, Kunio; Kundu, Tapas K

    2009-01-23

    Human transcriptional coactivator PC4 is a highly abundant nuclear protein that is involved in diverse cellular processes ranging from transcription to chromatin organization. Earlier, we have shown that PC4, a positive activator of p53, overexpresses upon genotoxic insult in a p53-dependent manner. In the present study, we show that PC4 stimulates ligase-mediated DNA end joining irrespective of the source of DNA ligase. Pull-down assays reveal that PC4 helps in the association of DNA ends through its C-terminal domain. In vitro nonhomologous end-joining assays with cell-free extracts show that PC4 enhances the joining of noncomplementary DNA ends. Interestingly, we found that PC4 activates double-strand break (DSB) repair activity through stimulation of DSB rejoining in vivo. Together, these findings demonstrate PC4 as an activator of nonhomologous end joining and DSB repair activity.

  12. Inositol polyphosphate multikinase is a transcriptional coactivator required for immediate early gene induction.

    PubMed

    Xu, Risheng; Paul, Bindu D; Smith, Dani R; Tyagi, Richa; Rao, Feng; Khan, A Basit; Blech, Daniel J; Vandiver, M Scott; Harraz, Maged M; Guha, Prasun; Ahmed, Ishrat; Sen, Nilkantha; Gallagher, Michela; Snyder, Solomon H

    2013-10-01

    Profound induction of immediate early genes (IEGs) by neural activation is a critical determinant for plasticity in the brain, but intervening molecular signals are not well characterized. We demonstrate that inositol polyphosphate multikinase (IPMK) acts noncatalytically as a transcriptional coactivator to mediate induction of numerous IEGs. IEG induction by electroconvulsive stimulation is virtually abolished in the brains of IPMK-deleted mice, which also display deficits in spatial memory. Neural activity stimulates binding of IPMK to the histone acetyltransferase CBP and enhances its recruitment to IEG promoters. Interestingly, IPMK regulation of CBP recruitment and IEG induction does not require its catalytic activities. Dominant-negative constructs, which prevent IPMK-CBP binding, substantially decrease IEG induction. As IPMK is ubiquitously expressed, its epigenetic regulation of IEGs may influence diverse nonneural and neural biologic processes.

  13. Human TAFII31 protein is a transcriptional coactivator of the p53 protein.

    PubMed Central

    Lu, H; Levine, A J

    1995-01-01

    The p53 protein activates transcription of a target gene by binding to a specific DNA response element and interacting with the transcriptional apparatus of RNA polymerase II. The amino-terminal domain of p53 interacts with a component of the TFIID basal transcription complex. The human TATA-binding-protein-associated factor TAFII31, a component of TFIID, has been identified as a critical protein required for p53-mediated transcriptional activation. TAFII31 and p53 proteins bind to each other via amino acid residues in the amino-terminal domain of p53 that are essential for transcription. Antibodies directed against TAFII31 protein inhibit p53-activated but not basal transcription in vitro. These results demonstrate that TAFII31 is a coactivator for the p53 protein. Images Fig. 3 Fig. 4 Fig. 6 PMID:7761466

  14. 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.

  15. DuOx2 Promoter Regulation by Hormones, Transcriptional Factors and the Coactivator TAZ.

    PubMed

    Cardoso-Weide, L C; Cardoso-Penha, R C; Costa, M W; Ferreira, A C F; Carvalho, D P; Santisteban, P S

    2015-03-01

    The production of H2O2, which is essential to thyroid hormone synthesis, involves two NADPH oxidases: dual oxidases 1 and 2 (DuOx1 and DuOx2). A functional study with human DuOx genes and their 5'-flanking regions showed that DuOx1 and -2 promoters are different from thyroid-specific gene promoters. Furthermore, their transcriptional activities are not restricted to thyroid cells. While regulation of Tg (thyroglobulin) and TPO (thyroperoxidase) expression have been extensively studied, DuOx2 promoter regulation by hormones and transcriptional factors need to be more explored. Herein we investigated the role of TSH, insulin and insulin-like growth factor 1 (IGF-1), as well as the cAMP effect on DuOx2 promoter (ptx41) activity in transfected rat thyroid cell lines (PCCL3). We also assessed DuOx2 promoter activity in the presence of transcriptional factors crucial to thyroid development such as TTF-1 (thyroid transcription factor 1), PAX8, CREB, DREAM, Nkx2.5 and the coactivator TAZ in HeLa and HEK 293T-transfected cells. Our results show that TSH and forskolin, which increase cAMP in thyroid cells, stimulated DuOx2 promoter activity. IGF-1 led to pronounced stimulation, while insulin induction was not statistically different from DuOx2 promoter basal activity. All transcriptional factors selected for this work and coactivator TAZ, except DREAM, stimulated DuOx2 promoter activity. Moreover, Nkx2.5 and TAZ synergistically increased DuOx2 promoter activity. In conclusion, we show that DuOx2 expression is regulated by hormones and transcription factors involved in thyroid organogenesis and carcinogenesis, reinforcing the importance of the control of H2O2 generation in the thyroid. PMID:25960956

  16. Steroid Receptor Coactivator 1 is an Integrator of Glucose and NAD+/NADH Homeostasis

    PubMed Central

    Motamed, Massoud; Rajapakshe, Kimal I.; Hartig, Sean M.; Coarfa, Cristian; Moses, Robb E.; Lonard, David M.

    2014-01-01

    Steroid receptor coactivator 1 (SRC-1) drives diverse gene expression programs necessary for the dynamic regulation of cancer metastasis, inflammation and gluconeogenesis, pointing to its overlapping roles as an oncoprotein and integrator of cell metabolic programs. Nutrient utilization has been intensely studied with regard to cellular adaptation in both cancer and noncancerous cells. Nonproliferating cells consume glucose through the citric acid cycle to generate NADH to fuel ATP generation via mitochondrial oxidative phosphorylation. In contrast, cancer cells undergo metabolic reprogramming to support rapid proliferation. To generate lipids, nucleotides, and proteins necessary for cell division, most tumors switch from oxidative phosphorylation to glycolysis, a phenomenon known as the Warburg Effect. Because SRC-1 is a key coactivator responsible for driving a hepatic gluconeogenic program under fasting conditions, we asked whether SRC-1 responds to alterations in nutrient availability to allow for adaptive metabolism. Here we show SRC-1 is stabilized by the 26S proteasome in the absence of glucose. RNA profiling was used to examine the effects of SRC-1 perturbation on gene expression in the absence or presence of glucose, revealing that SRC-1 affects the expression of complex I of the mitochondrial electron transport chain, a set of enzymes responsible for the conversion of NADH to NAD+. NAD+ and NADH were subsequently identified as metabolites that underlie SRC-1's response to glucose deprivation. Knockdown of SRC-1 in glycolytic cancer cells abrogated their ability to grow in the absence of glucose consistent with SRC-1's role in promoting cellular adaptation to reduced glucose availability. PMID:24438340

  17. Interactions with the bifunctional interface of the transcriptional coactivator DCoH1 are kinetically regulated.

    PubMed

    Wang, Dongli; Coco, Matthew W; Rose, Robert B

    2015-02-13

    Pterin-4a-carbinolamine dehydratase (PCD) is a highly conserved enzyme that evolved a second, unrelated function in mammals, as a transcriptional coactivator. As a coactivator, PCD is known as DCoH or dimerization cofactor of the transcription factor HNF-1. These two activities are associated with a change in oligomeric state: from two dimers interacting as an enzyme in the cytoplasm to a dimer interacting with a dimer of HNF-1 in the nucleus. The same interface of DCoH forms both complexes. To determine how DCoH partitions between its two functions, we studied the folding and stability of the DCoH homotetramer. We show that the DCoH1 homotetramer is kinetically trapped, meaning once it forms it will not dissociate to interact with HNF-1. In contrast, DCoH2, a paralog of DCoH1, unfolds within hours. A simple mutation in the interface of DCoH2 from Ser-51 to Thr, as found in DCoH1, increases the kinetic stability by 9 orders of magnitude, to τ(½) ∼ 2 million years. This suggests that the DCoH1·HNF-1 complex must co-fold to interact. We conclude that simple mutations can dramatically affect the dissociation kinetics of a complex. Residue 51 represents a "kinetic hot spot" instead of a "thermodynamic hot spot." Kinetic regulation allows PCD to adopt two distinct functions. Mutations in DCoH1 associated with diabetes affect both functions of DCoH1, perhaps by disrupting the balance between the two DCoH complexes.

  18. Interactions with the Bifunctional Interface of the Transcriptional Coactivator DCoH1 Are Kinetically Regulated*

    PubMed Central

    Wang, Dongli; Coco, Matthew W.; Rose, Robert B.

    2015-01-01

    Pterin-4a-carbinolamine dehydratase (PCD) is a highly conserved enzyme that evolved a second, unrelated function in mammals, as a transcriptional coactivator. As a coactivator, PCD is known as DCoH or dimerization cofactor of the transcription factor HNF-1. These two activities are associated with a change in oligomeric state: from two dimers interacting as an enzyme in the cytoplasm to a dimer interacting with a dimer of HNF-1 in the nucleus. The same interface of DCoH forms both complexes. To determine how DCoH partitions between its two functions, we studied the folding and stability of the DCoH homotetramer. We show that the DCoH1 homotetramer is kinetically trapped, meaning once it forms it will not dissociate to interact with HNF-1. In contrast, DCoH2, a paralog of DCoH1, unfolds within hours. A simple mutation in the interface of DCoH2 from Ser-51 to Thr, as found in DCoH1, increases the kinetic stability by 9 orders of magnitude, to τ½ ∼2 million years. This suggests that the DCoH1·HNF-1 complex must co-fold to interact. We conclude that simple mutations can dramatically affect the dissociation kinetics of a complex. Residue 51 represents a “kinetic hot spot” instead of a “thermodynamic hot spot.” Kinetic regulation allows PCD to adopt two distinct functions. Mutations in DCoH1 associated with diabetes affect both functions of DCoH1, perhaps by disrupting the balance between the two DCoH complexes. PMID:25538247

  19. 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

  20. Play: Children's Business and a Guide to Play Materials.

    ERIC Educational Resources Information Center

    Markun, Patricia Maloney, Ed.

    This collection of articles presents ideas about the value of children's play and suggests practical ways to implement good play experiences and select appropriate play materials. Articles examine play as an agent of social values, play and thinking, play and child development, the environmental opportunities for play factors that can destroy the…

  1. Identification of polyproline II regions derived from the proline-rich nuclear receptor coactivators PNRC and PNRC2: new insights for ERα coactivator interactions.

    PubMed

    Byrne, C; Miclet, E; Broutin, I; Gallo, D; Pelekanou, V; Kampa, M; Castanas, E; Leclercq, G; Jacquot, Y

    2013-10-01

    Protein-protein interactions are crucial for signal transductions required for cell differentiation and proliferation. Their modulation is therefore key to the development of therapeutic alternatives, particularly in the context of cancer. According to literature data, the polyproline-rich nuclear receptor coactivators PNRC and PNRC2 interact with estrogen receptor (ERα) through their PxxP SH3-binding motifs. In a search to identify the molecular features governing this interaction, we explored using electronic circular dichroism (ECD) spectroscopy and molecular dynamics (MD) calculations, the capacity of a range of putative biologically active peptides derived from these proteins and containing this PxxP motif(s) to form polyproline II (PPII) domains. An additional more exhaustive structural study on a lead PPII peptide was also performed using 2D nuclear magnetic resonance (NMR) spectroscopy. With the exception of one of all the investigated peptides (PNRC-D), binding assays failed to detect any affinity for Grb2 SH3 domains, suggesting that PPII motifs issued from Grb2 antagonists have a binding mode distinct from those derived from Grb2 agonists. Instead, the peptides revealed a competitive binding ability against a synthetic peptide (ERα17p) with a putative PPII-cognate domain located within a coregulator recruitment region of ERα (AF-2 site). Our work, which constitutes the first structure-related interaction study concerning PNRC and PNRC2, supports not only the existence of PxxP-induced PPII sequences in these coregulators, but also confirms the presence of a PPII recognition site in the AF-2 of the steroid receptor ERα, a region important for transcription regulation.

  2. Game-playing epilepsy.

    PubMed

    Siegel, M; Kurzrok, N; Barr, W B; Rowan, A J

    1992-01-01

    A 25-year-old woman with documented generalized seizures evoked by playing checkers was given a battery of psychological tests as well as a series of cognitive and non-game-related tasks during a session of intensive EEG-video monitoring. Generalized epileptiform discharges during each task, as well as during intervals of checkers playing, were quantified to determine possible triggering factors. Previous reports have discussed the roles of attention, concentration, stress, thinking, and spatial processing in similar cases. Our analysis showed significant activation of the EEG only with tasks involving strategic thinking, i.e., considering a sequence of moves based on evaluating the consequences of previous moves.

  3. Looking into Children's Play Communities

    ERIC Educational Resources Information Center

    Mabry, Mark; Fucigna, Carolee

    2009-01-01

    Play, particularly children's sociodramatic play, is the cornerstone of early childhood classrooms in the United States. Early childhood educators learn and expound mantras of "the value of play," "play-based programs," "children learning through play," and "play as child's work." They strive to promote the importance of making a place for play in…

  4. "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…

  5. 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…

  6. 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;…

  7. Bicentennial Plays and Programs.

    ERIC Educational Resources Information Center

    Fisher, Aileen

    This book contains royalty-free material on bicentennial themes for presentation by schools and amateur groups. The first section, Plays and Pageants, contains "Our Great Declaration,""A Star for Old Glory,""Sing, America, Sing,""Washington Marches On,""When Freedom Was News," and "A Dish of Green Peas." The second section, Playlets and…

  8. 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…

  9. Writing as Play.

    ERIC Educational Resources Information Center

    Rensenbrink, Carla

    1987-01-01

    Reveals ways to help students learn that writing can be similar to play, in that they can use their imaginations to create new settings and even new worlds. Suggests using toys, imaginary trips, and including friends in stories as inspiration for writing. (SKC)

  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. 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…

  12. 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…

  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. Games Professors Play

    ERIC Educational Resources Information Center

    Kenny, James A.; Herzing, Thomas W.

    1969-01-01

    The games are Build a Reputation (REP), Confuse the Student (CON), Blame the Opposition (BOP), and Pass the Buck (BUCK). Professors play these games because they "want to show off on occasion, . . . want to get off the hook and avoid responsibility, . . . are prone to blame others, or simply because they are lazy. (WM)

  15. PlayWrite.

    ERIC Educational Resources Information Center

    Amodeo, Janis

    This report describes the PlayWrite Program, which was developed in the Montville Township School District, New Jersey, to encourage children in grades K-6 to write. The primary objectives of the program are to increase students' motivation to write; to improve their writing skills through the process of brainstorming, composing, revising, and…

  16. Creative Outdoor Play Areas.

    ERIC Educational Resources Information Center

    Miller, Peggy L.

    Considering the creation of proper play areas for children (school sites, municipal and mini parks, private homes and backyards, shopping centers, apartment complexes, recreational areas, roadside parks, nursery schools, churches, summer camps, and drive-in theaters) as one of today's major challenges, the author recommends that professional…

  17. 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…

  18. The Paradoxes of Play.

    ERIC Educational Resources Information Center

    Rokosz, Francis M.

    1988-01-01

    The article makes a case against the structuring of intramural sports programs on the basis of the varsity athletics model, arguing that the latter model's components of competition and aggression mar the former's intrinsic rewards of play, creativity, and enhanced human relationships. (CB)

  19. 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.

  20. Drosophila salt-inducible kinase (SIK) regulates starvation resistance through cAMP-response element-binding protein (CREB)-regulated transcription coactivator (CRTC).

    PubMed

    Choi, Sekyu; Kim, Wonho; Chung, Jongkyeong

    2011-01-28

    Salt-inducible kinase (SIK), one of the AMP-activated kinase (AMPK)-related kinases, has been suggested to play important functions in glucose homeostasis by inhibiting the cAMP-response element-binding protein (CREB)-regulated transcription coactivator (CRTC). To examine the role of SIK in vivo, we generated Drosophila SIK mutant and found that the mutant flies have higher amounts of lipid and glycogen stores and are resistant to starvation. Interestingly, SIK transcripts are highly enriched in the brain, and we found that neuron-specific expression of exogenous SIK fully rescued lipid and glycogen storage phenotypes as well as starvation resistance of the mutant. Using genetic and biochemical analyses, we demonstrated that CRTC Ser-157 phosphorylation by SIK is critical for inhibiting CRTC activity in vivo. Furthermore, double mutants of SIK and CRTC became sensitive to starvation, and the Ser-157 phosphomimetic mutation of CRTC reduced lipid and glycogen levels in the SIK mutant, suggesting that CRTC mediates the effects of SIK signaling. Collectively, our results strongly support the importance of the SIK-CRTC signaling axis that functions in the brain to maintain energy homeostasis in Drosophila.

  1. Signal transduction in hypoxic cells: inducible nuclear translocation and recruitment of the CBP/p300 coactivator by the hypoxia-inducible factor-1alpha.

    PubMed

    Kallio, P J; Okamoto, K; O'Brien, S; Carrero, P; Makino, Y; Tanaka, H; Poellinger, L

    1998-11-16

    In response to decreased cellular oxygen concentrations the basic helix-loop-helix (bHLH)/PAS (Per, Arnt, Sim) hypoxia-inducible transcription factor, HIF-1alpha, mediates activation of networks of target genes involved in angiogenesis, erythropoiesis and glycolysis. Here we demonstrate that the mechanism of activation of HIF-1alpha is a multi-step process which includes hypoxia-dependent nuclear import and activation (derepression) of the transactivation domain, resulting in recruitment of the CREB-binding protein (CBP)/p300 coactivator. Inducible nuclear accumulation was shown to be dependent on a nuclear localization signal (NLS) within the C-terminal end of HIF-1alpha which also harbors the hypoxia-inducible transactivation domain. Nuclear import of HIF-1alpha was inhibited by either deletion or a single amino acid substitution within the NLS sequence motif and, within the context of the full-length protein, these mutations also resulted in inhibition of the transactivation activity of HIF-1alpha and recruitment of CBP. However, nuclear localization per se was not sufficient for transcriptional activation, since fusion of HIF-1alpha to the heterologous GAL4 DNA-binding domain generated a protein which showed constitutive nuclear localization but required hypoxic stimuli for function as a CBP-dependent transcription factor. Thus, hypoxia-inducible nuclear import and transactivation by recruitment of CBP can be functionally separated from one another and play critical roles in signal transduction by HIF-1alpha.

  2. 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.

  3. 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

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

    PubMed

    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

  5. 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.

  6. Zebrafish Trap230/Med12 is required as a coactivator for Sox9-dependent neural crest, cartilage and ear development.

    PubMed

    Rau, Marlene J; Fischer, Sabine; Neumann, Carl J

    2006-08-01

    The vertebrate Sox9 transcription factor directs the development of neural crest, otic placodes, cartilage and bone. In zebrafish, there are two Sox9 orthologs, Sox9a and Sox9b, which together perform the functions of the single-copy tetrapod Sox9. In a large-scale genetic screen, we have identified a novel zebrafish mutant that strongly resembles the Sox9a/Sox9b double mutant phenotype. We show that this mutation disrupts the zebrafish Trap230/Med12 ortholog, a member of the Mediator complex. Mediator is a coactivator complex transducing the interaction of DNA-binding transcription factors with RNA polymerase II, and our results reveal a critical function of the Trap230 subunit as a coactivator for Sox9.

  7. 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

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

    PubMed

    Kim, Jihyun; Fernand, Vivian E; Henagan, Tara M; Shin, Jeho; Huypens, Peter; Newman, Susan; Gettys, Thomas W; Chang, Ji Suk

    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

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

    PubMed

    Kim, Jihyun; Fernand, Vivian E; Henagan, Tara M; Shin, Jeho; Huypens, Peter; Newman, Susan; Gettys, Thomas W; Chang, Ji Suk

    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

  10. pX, the HBV-encoded coactivator, interacts with components of the transcription machinery and stimulates transcription in a TAF-independent manner.

    PubMed Central

    Haviv, I; Vaizel, D; Shaul, Y

    1996-01-01

    The X protein of hepatitis B virus (HBV) coactivates activators bearing potent (mostly acidic) activation domains. Here, we investigated the molecular mechanisms of this coactivation. We show that pX interacts with general transcription factors TFIIB and TFIIH, as well as with the potent activation domain of VP16. TFIIB interacts with both pX and VP16 simultaneously. In addition, the RNA polymerase II enzyme itself binds to pX. By reducing the activity of cellular coactivators, through squelching, we intensify the dependence of the activator on pX-mediated coactivation. Squelching is essentially diminished in the presence of pX, both in vivo and in vitro. The target of pX in this activity is the template-bound activator, and not the squelcher. Furthermore, by following transcription in a TAF-deprived reaction, we demonstrate absolute dependence of the activator on the activity of pX. We propose that pX coactivates transcription by substituting cellular coactivators in activator-preinitiation complex interactions. Images PMID:8670843

  11. Co-activation of AMPK and mTORC1 as a new therapeutic option for acute myeloid leukemia

    PubMed Central

    Sujobert, Pierre; Tamburini, Jerome

    2016-01-01

    ABSTRACT We report the therapeutic potential of GSK621, an AMP-activated protein kinase (AMPK) agonist, in acute myeloid leukemia (AML). GSK621-induced cytotoxicity is restricted to AML cells compared to normal hematopoietic progenitors due to a unique synthetic lethal interaction of co-activation of AMPK and mammalian target of rapamycin complex 1 (mTORC1) that involves the stress response pathway. AMPK activation thus represents an attractive perspective for cancer therapy. PMID:27652311

  12. Co-activation of AMPK and mTORC1 as a new therapeutic option for acute myeloid leukemia.

    PubMed

    Sujobert, Pierre; Tamburini, Jerome

    2016-07-01

    We report the therapeutic potential of GSK621, an AMP-activated protein kinase (AMPK) agonist, in acute myeloid leukemia (AML). GSK621-induced cytotoxicity is restricted to AML cells compared to normal hematopoietic progenitors due to a unique synthetic lethal interaction of co-activation of AMPK and mammalian target of rapamycin complex 1 (mTORC1) that involves the stress response pathway. AMPK activation thus represents an attractive perspective for cancer therapy. PMID:27652311

  13. 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

  14. Interdomain dynamics and coactivation of the mRNA decapping enzyme Dcp2 are mediated by a gatekeeper tryptophan

    PubMed Central

    Floor, Stephen N.; Borja, Mark S.; Gross, John D.

    2012-01-01

    Conformational dynamics in bilobed enzymes can be used to regulate their activity. One such enzyme, the eukaryotic decapping enzyme Dcp2, controls the half-life of mRNA by cleaving the 5′ cap structure, which exposes a monophosphate that is efficiently degraded by exonucleases. Decapping by Dcp2 is thought to be controlled by an open-to-closed transition involving formation of a composite active site with two domains sandwiching substrate, but many details of this process are not understood. Here, using NMR spectroscopy and enzyme kinetics, we show that Trp43 of Schizosaccharomyces pombe Dcp2 is a conserved gatekeeper of this open-to-closed transition. We find that Dcp2 samples multiple conformations in solution on the millisecond-microsecond timescale. Mutation of the gatekeeper tryptophan abolishes the dynamic behavior of Dcp2 and attenuates coactivation by a yeast enhancer of decapping (Edc1). Our results determine the dynamics of the open-to-closed transition in Dcp2, suggest a structural pathway for coactivation, predict that Dcp1 directly contacts the catalytic domain of Dcp2, and show that coactivation of decapping by Dcp2 is linked to formation of the composite active site. PMID:22323607

  15. Transcriptional coactivator HCF-1 couples the histone chaperone Asf1b to HSV-1 DNA replication components.

    PubMed

    Peng, Hua; Nogueira, Mauricio L; Vogel, Jodi L; Kristie, Thomas M

    2010-02-01

    The cellular transcriptional coactivator HCF-1 interacts with numerous transcription factors as well as other coactivators and is a component of multiple chromatin modulation complexes. The protein is essential for the expression of the immediate early genes of both herpes simplex virus (HSV) and varicella zoster virus and functions, in part, by coupling chromatin modification components including the Set1 or MLL1 histone methyltransferases and the histone demethylase LSD1 to promote the installation of positive chromatin marks and the activation of viral immediately early gene transcription. Although studies have investigated the role of HCF-1 in both cellular and viral transcription, little is known about other processes that the protein may be involved in. Here we demonstrate that HCF-1 localizes to sites of HSV replication late in infection. HCF-1 interacts directly and simultaneously with both HSV DNA replication proteins and the cellular histone chaperone Asf1b, a protein that regulates the progression of cellular DNA replication forks via chromatin reorganization. Asf1b localizes with HCF-1 in viral replication foci and depletion of Asf1b results in significantly reduced viral DNA accumulation. The results support a model in which the transcriptional coactivator HCF-1 is a component of the HSV DNA replication assembly and promotes viral DNA replication by coupling Asf1b to DNA replication components. This coupling provides a novel function for HCF-1 and insights into the mechanisms of modulating chromatin during DNA replication.

  16. The transcriptional coactivator DRIP/mediator complex is involved in vitamin D receptor function and regulates keratinocyte proliferation and differentiation.

    PubMed

    Oda, Yuko; Chalkley, Robert J; Burlingame, Alma L; Bikle, Daniel D

    2010-10-01

    Mediator is a multisubunit coactivator complex that facilitates transcription of nuclear receptors. We investigated the role of the mediator complex as a coactivator for vitamin D receptor (VDR) in keratinocytes. Using VDR affinity beads, the vitamin D receptor interacting protein (DRIP)/mediator complex was purified from primary keratinocytes, and its subunit composition was determined by mass spectrometry. The complex included core subunits, such as DRIP205/MED1 (MED1), that directly binds to VDR. Additional subunits were identified that are components of the RNA polymerase II complex. The functions of different mediator components were investigated by silencing its subunits. The core subunit MED1 facilitates VDR activity and regulating keratinocyte proliferation and differentiation. A newly described subunit MED21 also has a role in promoting keratinocyte proliferation and differentiation, whereas MED10 has an inhibitory role. Blocking MED1/MED21 expression caused hyperproliferation of keratinocytes, accompanied by increases in mRNA expression of the cell cycle regulator cyclin D1 and/or glioma-associated oncogene homolog. Blocking MED1 or MED21 expression also resulted in defects in calcium-induced keratinocyte differentiation, as indicated by decreased expression of differentiation markers and decreased translocation of E-cadherin to the membrane. These results show that keratinocytes use the transcriptional coactivator mediator to regulate VDR functions and control keratinocyte proliferation and differentiation.

  17. A novel nuclear role for the Vav3 nucleotide exchange factor in androgen receptor coactivation in prostate cancer.

    PubMed

    Rao, S; Lyons, L S; Fahrenholtz, C D; Wu, F; Farooq, A; Balkan, W; Burnstein, K L

    2012-02-01

    Increased androgen receptor (AR) transcriptional activity mediated by coactivator proteins may drive castration-resistant prostate cancer (CRPC) growth. Vav3, a Rho GTPase guanine nucleotide exchange factor (GEF), is overexpressed in human prostate cancers, particularly in models of CRPC progression. Vav3 coactivates AR in a Vav3 pleckstrin homology (PH) domain-dependent but GEF-independent manner. Ectopic expression of Vav3 in androgen-dependent human prostate cancer cells conferred robust castration-resistant xenograft tumor growth. Vav3 but not a Vav3 PH mutant greatly stimulated interaction between the AR amino and carboxyl termini (N-C interaction), which is required for maximal receptor transcriptional activity. Vav3 was distributed between the cytoplasm and nucleus with nuclear localization-dependent on the Vav3 PH domain. Membrane targeting of Vav3 abolished Vav3 potentiation of AR activity, whereas nuclear targeting of a Vav3 PH mutant rescued AR coactivation, suggesting that nuclear localization is an important function of the Vav3 PH domain. A nuclear role for Vav3 was further demonstrated by sequential chromatin immunoprecipitation assays, which revealed that Vav3 and AR were recruited to the same transcriptional complexes of an AR target gene enhancer. These data demonstrate the importance of Vav3 in CRPC and define a novel nuclear function of Vav3 in regulating AR activity.

  18. Play in Practice: Case Studies in Young Children's Play.

    ERIC Educational Resources Information Center

    Brown, Cheryl Render, Ed.; Marchant, Catherine, Ed.

    This book uses a collection of stories, or "cases," as a basis for reflection, discussion, and learning about the many roles "play" has in children's lives. Each of the 12 cases addresses an issue of play from one of three categories--the role of adults in play, the cultural meanings of play, and the issues related to play in special settings.…

  19. Abscisic acid promotes proteasome-mediated degradation of the transcription coactivator NPR1 in Arabidopsis thaliana.

    PubMed

    Ding, Yezhang; Dommel, Matthew; Mou, Zhonglin

    2016-04-01

    Proteasome-mediated turnover of the transcription coactivator NPR1 is pivotal for efficient activation of the broad-spectrum plant immune responses known as localized acquired resistance (LAR) and systemic acquired resistance (SAR) in adjacent and systemic tissues, respectively, and requires the CUL3-based E3 ligase and its adaptor proteins, NPR3 and NPR4, which are receptors for the signaling molecule salicylic acid (SA). It has been shown that SA prevents NPR1 turnover under non-inducing and LAR/SAR-inducing conditions, but how cellular NPR1 homeostasis is maintained remains unclear. Here, we show that the phytohormone abscisic acid (ABA) and SA antagonistically influence cellular NPR1 protein levels. ABA promotes NPR1 degradation via the CUL3(NPR) (3/) (NPR) (4) complex-mediated proteasome pathway, whereas SA may protect NPR1 from ABA-promoted degradation through phosphorylation. Furthermore, we demonstrate that the timing and strength of SA and ABA signaling are critical in modulating NPR1 accumulation and target gene expression. Perturbing ABA or SA signaling in adjacent tissues alters the temporal dynamic pattern of NPR1 accumulation and target gene transcription. Finally, we show that sequential SA and ABA treatment leads to dynamic changes in NPR1 protein levels and target gene expression. Our results revealed a tight correlation between sequential SA and ABA signaling and dynamic changes in NPR1 protein levels and NPR1-dependent transcription in plant immune responses. PMID:26865090

  20. 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

  1. 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.

  2. 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

  3. 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

  4. 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

  5. Coactivator MBF1 preserves the redox-dependent AP-1 activity during oxidative stress in Drosophila

    PubMed Central

    Jindra, Marek; Gaziova, Ivana; Uhlirova, Mirka; Okabe, Masataka; Hiromi, Yasushi; Hirose, Susumu

    2004-01-01

    Basic leucine zipper proteins Jun and Fos form the dimeric transcription factor AP-1, essential for cell differentiation and immune and antioxidant defenses. AP-1 activity is controlled, in part, by the redox state of critical cysteine residues within the basic regions of Jun and Fos. Mutation of these cysteines contributes to oncogenic potential of Jun and Fos. How cells maintain the redox-dependent AP-1 activity at favorable levels is not known. We show that the conserved coactivator MBF1 is a positive modulator of AP-1. Via a direct interaction with the basic region of Drosophila Jun (D-Jun), MBF1 prevents an oxidative modification (S-cystenyl cystenylation) of the critical cysteine and stimulates AP-1 binding to DNA. Cytoplasmic MBF1 translocates to the nucleus together with a transfected D-Jun protein, suggesting that MBF1 protects nascent D-Jun also in Drosophila cells. mbf1-null mutants live shorter than mbf1+ controls in the presence of hydrogen peroxide (H2O2). An AP-1-dependent epithelial closure becomes sensitive to H2O2 in flies lacking MBF1. We conclude that by preserving the redox-sensitive AP-1 activity, MBF1 provides an advantage during oxidative stress. PMID:15306851

  6. 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

  7. 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

  8. 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

  9. [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

  10. 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.

  11. Oncogenic steroid receptor coactivator-3 is a key regulator of the white adipogenic program

    PubMed Central

    Louet, Jean-Francois; Coste, Agnès; Amazit, Larbi; Tannour-Louet, Mounia; Wu, Ray-Chang; Tsai, Sophia Y.; Tsai, Ming-Jer; Auwerx, Johan; O'Malley, Bert W.

    2006-01-01

    The white adipocyte is at the center of dysfunctional regulatory pathways in various pathophysiological processes, including obesity, diabetes, inflammation, and cancer. Here, we show that the oncogenic steroid receptor coactivator-3 (SRC-3) is a critical regulator of white adipocyte development. Indeed, in SRC-3−/− mouse embryonic fibroblasts, adipocyte differentiation was severely impaired, and reexpression of SRC-3 was able to restore it. The early stages of adipocyte differentiation are accompanied by an increase in nuclear levels of SRC-3, which accumulates to high levels specifically in the nucleus of differentiated fat cells. Moreover, SRC-3−/− animals showed reduced body weight and adipose tissue mass with a significant decrease of the expression of peroxisome proliferator-activated receptor γ2 (PPARγ2), a master gene required for adipogenesis. At the molecular level, SRC-3 acts synergistically with the transcription factor CAAT/enhancer-binding protein to control the gene expression of PPARγ2. Collectively, these data suggest a crucial role for SRC-3 as an integrator of the complex transcriptional network controlling adipogenesis. PMID:17098861

  12. Photoperiodic regulation of androgen receptor and steroid receptor coactivator-1 in Siberian hamster brain.

    PubMed

    Tetel, Marc J; Ungar, Todd C; Hassan, Brett; Bittman, Eric L

    2004-11-24

    Seasonal changes in the neuroendocrine actions of gonadal steroid hormones are triggered by fluctuations in daylength. The mechanisms responsible for photoperiodic influences upon the feedback and behavioral effects of testosterone in Siberian hamsters are poorly understood. We hypothesized that daylength regulates the expression of androgen receptor (AR) and/or steroid receptor coactivator-1 (SRC-1) in specific forebrain regions. Hamsters were castrated and implanted with either oil-filled capsules or low doses of testosterone; half of the animals remained in 16L/8D and the rest were kept in 10L/14D for the ensuing 70 days. The number of AR-immunoreactive (AR-ir) cells was regulated by testosterone in medial amygdala and caudal arcuate, and by photoperiod in the medial preoptic nucleus and the posterodorsal medial amygdala. A significant interaction between photoperiod and androgen treatment was found in medial preoptic nucleus and posterodorsal medial amygdala. The molecular weight and distribution of SRC-1 were similar to reports in other rodent species, and short days reduced the number of SRC-1-ir cells in posteromedial bed nucleus of the stria terminalis (BNST) and posterodorsal medial amygdala. A significant interaction between androgen treatment and daylength in regulation of SRC-1-ir was found in anterior medial amygdala. The present results indicate that daylength-induced fluctuations in SRC-1 and AR expression may contribute to seasonally changing effects of testosterone.

  13. 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

  14. Prediction of missing flow records using multilayer perceptron and coactive neurofuzzy inference system.

    PubMed

    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 R (2) 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

  15. 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.

  16. 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

  17. Mitochondrial Fusion Is Increased by the Nuclear Coactivator PGC-1β

    PubMed Central

    Liesa, Marc; Borda-d'Água, Bárbara; Medina-Gómez, Gema; Lelliott, Christopher J.; Paz, José Carlos; Rojo, Manuel; Palacín, Manuel; Vidal-Puig, Antonio; Zorzano, Antonio

    2008-01-01

    Background There is no evidence to date on whether transcriptional regulators are able to shift the balance between mitochondrial fusion and fission events through selective control of gene expression. Methodology/Principal Findings Here, we demonstrate that reduced mitochondrial size observed in knock-out mice for the transcriptional regulator PGC-1β is associated with a selective reduction in Mitofusin 2 (Mfn2) expression, a mitochondrial fusion protein. This decrease in Mfn2 is specific since expression of the remaining components of mitochondrial fusion and fission machinery were not affected. Furthermore, PGC-1β increases mitochondrial fusion and elongates mitochondrial tubules. This PGC-1β-induced elongation specifically requires Mfn2 as this process is absent in Mfn2-ablated cells. Finally, we show that PGC-1β increases Mfn2 promoter activity and transcription by coactivating the nuclear receptor Estrogen Related Receptor α (ERRα). Conclusions/Significance Taken together, our data reveal a novel mechanism by which mammalian cells control mitochondrial fusion. In addition, we describe a novel role of PGC-1β in mitochondrial physiology, namely the control of mitochondrial fusion mainly through Mfn2. PMID:18974884

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

    PubMed

    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

    2016-02-01

    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.

  19. The tumor suppressor Nf2 regulates corpus callosum development by inhibiting the transcriptional coactivator Yap

    PubMed Central

    Lavado, Alfonso; Ware, Michelle; Paré, Joshua; Cao, Xinwei

    2014-01-01

    The corpus callosum connects cerebral hemispheres and is the largest axon tract in the mammalian brain. Callosal malformations are among the most common congenital brain anomalies and are associated with a wide range of neuropsychological deficits. Crossing of the midline by callosal axons relies on a proper midline environment that harbors guidepost cells emitting guidance cues to instruct callosal axon navigation. Little is known about what controls the formation of the midline environment. We find that two components of the Hippo pathway, the tumor suppressor Nf2 (Merlin) and the transcriptional coactivator Yap (Yap1), regulate guidepost development and expression of the guidance cue Slit2 in mouse. During normal brain development, Nf2 suppresses Yap activity in neural progenitor cells to promote guidepost cell differentiation and prevent ectopic Slit2 expression. Loss of Nf2 causes malformation of midline guideposts and Slit2 upregulation, resulting in callosal agenesis. Slit2 heterozygosity and Yap deletion both restore callosal formation in Nf2 mutants. Furthermore, selectively elevating Yap activity in midline neural progenitors is sufficient to disrupt guidepost formation, upregulate Slit2 and prevent midline crossing. The Hippo pathway is known for its role in controlling organ growth and tumorigenesis. Our study identifies a novel role of this pathway in axon guidance. Moreover, by linking axon pathfinding and neural progenitor behaviors, our results provide an example of the intricate coordination between growth and wiring during brain development. PMID:25336744

  20. Hepatic Insulin Resistance Following Chronic Activation of the CREB Coactivator CRTC2.

    PubMed

    Hogan, Meghan F; Ravnskjaer, Kim; Matsumura, Shigenobu; Huising, Mark O; Hull, Rebecca L; Kahn, Steven E; Montminy, Marc

    2015-10-23

    Under fasting conditions, increases in circulating concentrations of glucagon maintain glucose homeostasis via the induction of hepatic gluconeogenesis. Triggering of the cAMP pathway in hepatocytes stimulates the gluconeogenic program via the PKA-mediated phosphorylation of CREB and dephosphorylation of the cAMP-regulated CREB coactivators CRTC2 and CRTC3. In parallel, decreases in circulating insulin also increase gluconeogenic gene expression via the de-phosphorylation and activation of the forkhead transcription factor FOXO1. Hepatic gluconeogenesis is increased in insulin resistance where it contributes to the attendant hyperglycemia. Whether selective activation of the hepatic CREB/CRTC pathway is sufficient to trigger metabolic changes in other tissues is unclear, however. Modest hepatic expression of a phosphorylation-defective and therefore constitutively active CRTC2S171,275A protein increased gluconeogenic gene expression under fasting as well as feeding conditions. Circulating glucose concentrations were constitutively elevated in CRTC2S171,275A-expressing mice, leading to compensatory increases in circulating insulin concentrations that enhance FOXO1 phosphorylation. Despite accompanying decreases in FOXO1 activity, hepatic gluconeogenic gene expression remained elevated in CRTC2S171,275A mice, demonstrating that chronic increases in CRTC2 activity in the liver are indeed sufficient to promote hepatic insulin resistance and to disrupt glucose homeostasis.

  1. Hepatic Insulin Resistance Following Chronic Activation of the CREB Coactivator CRTC2*

    PubMed Central

    Hogan, Meghan F.; Ravnskjaer, Kim; Matsumura, Shigenobu; Huising, Mark O.; Hull, Rebecca L.; Kahn, Steven E.; Montminy, Marc

    2015-01-01

    Under fasting conditions, increases in circulating concentrations of glucagon maintain glucose homeostasis via the induction of hepatic gluconeogenesis. Triggering of the cAMP pathway in hepatocytes stimulates the gluconeogenic program via the PKA-mediated phosphorylation of CREB and dephosphorylation of the cAMP-regulated CREB coactivators CRTC2 and CRTC3. In parallel, decreases in circulating insulin also increase gluconeogenic gene expression via the de-phosphorylation and activation of the forkhead transcription factor FOXO1. Hepatic gluconeogenesis is increased in insulin resistance where it contributes to the attendant hyperglycemia. Whether selective activation of the hepatic CREB/CRTC pathway is sufficient to trigger metabolic changes in other tissues is unclear, however. Modest hepatic expression of a phosphorylation-defective and therefore constitutively active CRTC2S171,275A protein increased gluconeogenic gene expression under fasting as well as feeding conditions. Circulating glucose concentrations were constitutively elevated in CRTC2S171,275A-expressing mice, leading to compensatory increases in circulating insulin concentrations that enhance FOXO1 phosphorylation. Despite accompanying decreases in FOXO1 activity, hepatic gluconeogenic gene expression remained elevated in CRTC2S171,275A mice, demonstrating that chronic increases in CRTC2 activity in the liver are indeed sufficient to promote hepatic insulin resistance and to disrupt glucose homeostasis. PMID:26342077

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

    PubMed

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

    2014-05-01

    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.

  3. Molecular Basis for the Regulation of Transcriptional Coactivator p300 in Myogenic Differentiation.

    PubMed

    Chen, Jihong; Wang, Yingjian; Hamed, Munerah; Lacroix, Natascha; Li, Qiao

    2015-09-10

    Skeletal myogenesis is a highly ordered process which specifically depends on the function of transcriptional coactivator p300. Previous studies have established that Akt/protein kinase B (PKB), a positive regulator of p300 in proliferating cells, is also important for proper skeletal muscle development. Nevertheless, it is not clear as to how the p300 is regulated by myogenic signaling events given that both p300 and Akt are involved in many cellular processes. Our studies revealed that the levels of p300 protein are temporally maintained in ligand-enhanced skeletal myocyte development. Interestingly, this maintenance of p300 protein is observed at the stage of myoblast differentiation, which coincides with an increase in Akt phosphorylation. Moreover, regulation of p300 during myoblast differentiation appears to be mediated by Akt signaling. Blunting of p300 impairs myogenic expression and myoblast differentiation. Thus, our data suggests a particular role for Akt in myoblast differentiation through interaction with p300. Our studies also establish the potential of exploiting p300 regulation and Akt activation to decipher the complex signaling cascades involved in skeletal muscle development.

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

    PubMed

    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

    2012-02-21

    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.

  5. Cidea is an essential transcriptional coactivator regulating mammary gland secretion of milk lipids.

    PubMed

    Wang, Wenshan; Lv, Na; Zhang, Shasha; Shui, Guanghou; Qian, Hui; Zhang, Jingfeng; Chen, Yuanying; Ye, Jing; Xie, Yuansheng; Shen, Yuemao; Wenk, Markus R; Li, Peng

    2012-01-15

    Adequate lipid secretion by mammary glands during lactation is essential for the survival of mammalian offspring. However, the mechanism governing this process is poorly understood. Here we show that Cidea is expressed at high levels in lactating mammary glands and its deficiency leads to premature pup death as a result of severely reduced milk lipids. Furthermore, the expression of xanthine oxidoreductase (XOR), an essential factor for milk lipid secretion, is markedly lower in Cidea-deficient mammary glands. Conversely, ectopic Cidea expression induces the expression of XOR and enhances lipid secretion in vivo. Unexpectedly, as Cidea has heretofore been thought of as a cytoplasmic protein, we detected it in the nucleus and found it to physically interact with transcription factor CCAAT/enhancer-binding protein β (C/EBPβ) in mammary epithelial cells. We also observed that Cidea induces XOR expression by promoting the association of C/EBPβ onto, and the dissociation of HDAC1 from, the promoter of the Xdh gene encoding XOR. Finally, we found that Fsp27, another CIDE family protein, is detected in the nucleus and interacts with C/EBPβ to regulate expression of a subset of C/EBPβ downstream genes in adipocytes. Thus, Cidea acts as a previously unknown transcriptional coactivator of C/EBPβ in mammary glands to control lipid secretion and pup survival.

  6. Overexpression of transcriptional coactivator AIB1 promotes hepatocellular carcinoma progression by enhancing cell proliferation and invasiveness.

    PubMed

    Xu, Y; Chen, Q; Li, W; Su, X; Chen, T; Liu, Y; Zhao, Y; Yu, C

    2010-06-10

    Amplified in breast cancer 1 (AIB1) is a transcriptional coactivator for nuclear receptors and other transcription factors. AIB1 has an important role in malignancy of several cancers such as breast and prostate cancers. However, its involvement in human hepatocellular carcinoma (HCC) progression remains unclear. Here, we found that AIB1 protein was overexpressed in 23 of 34 human HCC specimens (68%). Down-regulation of AIB1 reduced HCC cell proliferation, migration, invasion, colony formation ability and tumorigenic potential in nude mice. These phenotypic changes caused by AIB1 knockdown correlated with increased expression of the cell cycle inhibitor p21(Cip1/Waf1) and decreased Akt activation and the expression of proliferating cell nuclear antigen (PCNA) and matrix metallopeptidase MMP-9. In agreement with these findings, clinical AIB1-positive HCC expressed higher levels of PCNA than AIB1-negative HCC. A positive correlation was established between the levels of AIB1 protein and PCNA protein in HCC, suggesting that AIB1 may contribute to HCC cell proliferation. In addition, MMP-9 expression in AIB1-postive HCC was significantly higher than that in AIB1-negative HCC, suggesting that AIB1-postive HCC may be more invasive. Collectively, our results show that overexpression of AIB1 promotes human HCC progression by enhancing cell proliferation and invasiveness. Therefore, AIB1 is a master regulator of human HCC growth and might be a useful molecular target for HCC prognosis and treatment.

  7. Activity-dependent transport of the transcriptional coactivator CRTC1 from synapse to nucleus.

    PubMed

    Ch'ng, Toh Hean; Uzgil, Besim; Lin, Peter; Avliyakulov, Nuraly K; O'Dell, Thomas J; Martin, Kelsey C

    2012-07-01

    Long-lasting changes in synaptic efficacy, such as those underlying long-term memory, require transcription. Activity-dependent transport of synaptically localized transcriptional regulators provides a direct means of coupling synaptic stimulation with changes in transcription. The CREB-regulated transcriptional coactivator (CRTC1), which is required for long-term hippocampal plasticity, binds CREB to potently promote transcription. We show that CRTC1 localizes to synapses in silenced hippocampal neurons but translocates to the nucleus in response to localized synaptic stimulation. Regulated nuclear translocation occurs only in excitatory neurons and requires calcium influx and calcineurin activation. CRTC1 is controlled in a dual fashion with activity regulating CRTC1 nuclear translocation and cAMP modulating its persistence in the nucleus. Neuronal activity triggers a complex change in CRTC1 phosphorylation, suggesting that CRTC1 may link specific types of stimuli to specific changes in gene expression. Together, our results indicate that synapse-to-nuclear transport of CRTC1 dynamically informs the nucleus about synaptic activity.

  8. Transcriptional coactivator CIITA, a functional homolog of TAF1, has kinase activity.

    PubMed

    Soe, Katherine C; Devaiah, Ballachanda N; Singer, Dinah S

    2013-11-01

    The Major Histocompatibility Complex (MHC) class II transactivator (CIITA) mediates activated immune responses and its deficiency results in the Type II Bare Lymphocyte Syndrome. CIITA is a transcriptional co-activator that regulates γ-interferon-activated transcription of MHC class I and class II genes. It is also a functional homolog of TAF1, a component of the general transcription factor complex TFIID. TAF1 and CIITA both possess intrinsic acetyltransferase (AT) activity that is required for transcription initiation. In response to induction by γ-interferon, CIITA and it's AT activity bypass the requirement for TAF1 AT activity. TAF1 also has kinase activity that is essential for its function. However, no similar activity has been identified for CIITA thus far. Here we report that CIITA, like TAF1, is a serine-threonine kinase. Its substrate specificity parallels, but does not duplicate, that of TAF1 in phosphorylating the TFIID component TAF7, the RAP74 subunit of the general transcription factor TFIIF and histone H2B. Like TAF1, CIITA autophosphorylates, affecting its interaction with TAF7. Additionally, CIITA phosphorylates histone H2B at Ser36, a target of TAF1 that is required for transcription during cell cycle progression and stress response. However, unlike TAF1, CIITA also phosphorylates all the other histones. The identification of this novel kinase activity of CIITA further clarifies its role as a functional homolog of TAF1 which may operate during stress and γ-IFN activated MHC gene transcription.

  9. Yes-associated protein (YAP) transcriptional coactivator functions in balancing growth and differentiation in skin.

    PubMed

    Zhang, Haiying; Pasolli, H Amalia; Fuchs, Elaine

    2011-02-01

    In mammals, skin begins as a single-layered epithelium, which, through a series of signals, either stratifies and differentiates to become epidermis or invaginates downward to make hair follicles (HFs). To achieve and maintain proper tissue architecture, keratinocytes must intricately balance growth and differentiation. Here, we uncover a critical and hitherto unappreciated role for Yes-associated protein (YAP), an evolutionarily conserved transcriptional coactivator with potent oncogenic potential. We show that YAP is highly expressed and nuclear in single-layered basal epidermal progenitors. Notably, nuclear YAP progressively declines with age and correlates with proliferative potential of epidermal progenitors. Shortly after initiation of HF morphogenesis, YAP translocates to the cytoplasm of differentiating cells. Through genetic analysis, we demonstrate a role for YAP in maintaining basal epidermal progenitors and regulating HF morphogenesis. YAP overexpression causes hair placodes to evaginate into epidermis rather than invaginate into dermis. YAP also expands basal epidermal progenitors, promotes proliferation, and inhibits terminal differentiation. In vitro gain-and-loss of function studies show that primary mouse keratinocytes (MKs) accelerate proliferation, suppress differentiation, and inhibit apoptosis when YAP is activated and reverse these features when YAP is inhibited. Finally, we identify Cyr61 as a target of YAP in MKs and demonstrate a requirement for TEA domain (TEAD) transcriptional factors to comediate YAP functions in MKs.

  10. 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.

  11. A C-terminal acidic domain regulates degradation of the transcriptional coactivator Bob1.

    PubMed

    Lindner, John M; Wong, Christina S F; Möller, Andreas; Nielsen, Peter J

    2013-12-01

    Bob1 (Obf-1 or OCA-B) is a 34-kDa transcriptional coactivator encoded by the Pou2af1 gene that is essential for normal B-cell development and immune responses in mice. During lymphocyte activation, Bob1 protein levels dramatically increase independently of mRNA levels, suggesting that the stability of Bob1 is regulated. We used a fluorescent protein-based reporter system to analyze protein stability in response to genetic and physiological perturbations and show that, while Bob1 degradation is proteasome mediated, it does not require ubiquitination of Bob1. Furthermore, degradation of Bob1 in B cells appears to be largely independent of the E3 ubiquitin ligase Siah. We propose a novel mechanism of Bob1 turnover in B cells, whereby an acidic region in the C terminus of Bob1 regulates the activity of degron signals elsewhere in the protein. Changes that make the C terminus more acidic, including tyrosine phosphorylation-mimetic mutations, stabilize the instable murine Bob1 protein, indicating that B cells may regulate Bob1 stability and activity via signaling pathways. Finally, we show that expressing a stable Bob1 mutant in B cells suppresses cell proliferation and induces changes in surface marker expression commonly seen during B-cell differentiation.

  12. The tumor suppressor Nf2 regulates corpus callosum development by inhibiting the transcriptional coactivator Yap.

    PubMed

    Lavado, Alfonso; Ware, Michelle; Paré, Joshua; Cao, Xinwei

    2014-11-01

    The corpus callosum connects cerebral hemispheres and is the largest axon tract in the mammalian brain. Callosal malformations are among the most common congenital brain anomalies and are associated with a wide range of neuropsychological deficits. Crossing of the midline by callosal axons relies on a proper midline environment that harbors guidepost cells emitting guidance cues to instruct callosal axon navigation. Little is known about what controls the formation of the midline environment. We find that two components of the Hippo pathway, the tumor suppressor Nf2 (Merlin) and the transcriptional coactivator Yap (Yap1), regulate guidepost development and expression of the guidance cue Slit2 in mouse. During normal brain development, Nf2 suppresses Yap activity in neural progenitor cells to promote guidepost cell differentiation and prevent ectopic Slit2 expression. Loss of Nf2 causes malformation of midline guideposts and Slit2 upregulation, resulting in callosal agenesis. Slit2 heterozygosity and Yap deletion both restore callosal formation in Nf2 mutants. Furthermore, selectively elevating Yap activity in midline neural progenitors is sufficient to disrupt guidepost formation, upregulate Slit2 and prevent midline crossing. The Hippo pathway is known for its role in controlling organ growth and tumorigenesis. Our study identifies a novel role of this pathway in axon guidance. Moreover, by linking axon pathfinding and neural progenitor behaviors, our results provide an example of the intricate coordination between growth and wiring during brain development.

  13. 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…

  14. The Neglected Factor-Play

    ERIC Educational Resources Information Center

    Feitelson, Dina; Ross, Gail S.

    1973-01-01

    Spontaneous thematic play behavior in children is investigated. Environmental prerequisites of play and possible functions of play in cognitive and personality development are discussed. Whether modelling is a prerequisite for thematic play, and the relationship between level of play and creativity test performance in children are assessed. (DP)

  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. 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.

  17. 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)

  18. 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…

  19. 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…

  20. Skeletal Consequences of Deletion of Steroid Receptor Coactivator-2/Transcription Intermediary Factor-2*

    PubMed Central

    Mödder, Ulrike I.; Monroe, David G.; Fraser, Daniel G.; Spelsberg, Thomas C.; Rosen, Clifford J.; Géhin, Martine; Chambon, Pierre; O'Malley, Bert W.; Khosla, Sundeep

    2009-01-01

    Both estrogen receptor (ER) and peroxisome proliferator-activated receptor γ (PPARγ) regulate bone metabolism, and because steroid receptor coactivator (SRC)-2 (TIF-2) enhances ER and PPARγ activity, we examined the consequences of deletion of SRC-2 on bone using SRC-2 knock out (KO) mice. Loss of SRC-2 resulted in increased bone mass, with SRC-2 KO mice having 80% higher trabecular bone volume as compared with wild type mice. SRC-2 KO mice also had a marked decrease (by 50%) in bone marrow adipocytes. These data suggested that marrow precursor cells in the SRC-2 KO mice may be resistant to the inhibitory effects of endogenous PPARγ ligands on bone formation. Consistent with this, compared with cultures from wild type mice, marrow stromal cultures from SRC-2 KO mice formed significantly more mineralized nodules (by 3-fold) in the presence of the PPARγ agonist, rosiglitazone. Using chromatin immunoprecipitation analysis, we demonstrated that in bone marrow stromal cells, loss of SRC-2 leads to destabilization of the transcription complex at the peroxisome proliferator response elements of a number of PPARγ target genes, resulting in an overall decrease in the expression of adipocyte-related genes and a marked decrease in adipocyte development. Using ovariectomy with or without estrogen replacement, we also demonstrated that SRC-2 KO mice were partially resistant to the skeletal actions of estrogen. Collectively, these findings indicate that loss of SRC-2 leads to partial skeletal resistance to the ER and PPARγ, but resistance to PPARγ is dominant, leading to increased bone mass. Modulating SRC-2 action may, thus, represent a novel therapeutic target for osteoporosis. PMID:19423703

  1. 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

  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

    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

    2015-07-01

    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.

  4. 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

  5. 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

  6. 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

  7. 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

  8. Human transcriptional coactivator with PDZ-binding motif (TAZ) is downregulated during decidualization.

    PubMed

    Strakova, Zuzana; Reed, Jennifer; Ihnatovych, Ivanna

    2010-06-01

    Transcriptional coactivator with PDZ-binding motif (TAZ) is known to bind to a variety of transcription factors to control cell differentiation and organ development. However, its role in uterine physiology has not yet been described. To study its regulation during the unique process of differentiation of fibroblasts into decidual cells (decidualization), we utilized the human uterine fibroblast (HuF) in vitro cell model. Immunocytochemistry data demonstrated that the majority of the TAZ protein is localized in the nucleus. Treatment of HuF cells with the embryonic stimulus cytokine interleukin 1 beta in the presence of steroid hormones (estradiol-17 beta and medroxyprogesterone acetate) for 13 days did not cause any apparent TAZ mRNA changes but resulted in a significant TAZ protein decline (approximately 62%) in total cell lysates. Analysis of cytosolic and nuclear extracts revealed that the decline of total TAZ was caused primarily by a drop of TAZ protein levels in the nucleus. TAZ was localized on the peroxisome proliferator-activated receptor response element site (located at position -1200 bp relative to the transcription start site) of the genomic region of decidualization marker insulin-like growth factor-binding protein 1 (IGFBP1) in HuF cells as detected by chromatin immunoprecipitation. TAZ is also present in human endometrium tissue as confirmed by immunohistochemistry. During the secretory phase of the menstrual cycle, specific TAZ staining particularly diminishes in the stroma, suggesting its participation during the decidualization process, as well as implantation. During early baboon pregnancy, TAZ protein expression remains minimal in the endometrium close to the implantation site. In summary, the presented evidence shows for the first time to date TAZ protein in the human uterine tract, its downregulation during in vitro decidualization, and its localization on the IGFBP1 promoter region, all of which indicate its presence in the uterine

  9. Transcriptional coactivator p300 regulates glucose-induced gene expression in endothelial cells.

    PubMed

    Chen, Shali; Feng, Biao; George, Biju; Chakrabarti, Rana; Chen, Megan; Chakrabarti, Subrata

    2010-01-01

    Sustained hyperglycemia in diabetes causes alteration of a large number of transcription factors and mRNA transcripts, leading to tissue damage. We investigated whether p300, a transcriptional coactivator with histone acetyl transferase activity, regulates glucose-induced activation of transcription factors and subsequent upregulation of vasoactive factors and extracellular matrix (ECM) proteins in human umbilical vein endothelial cells (HUVECs). HUVECs were incubated in varied glucose concentrations and were studied after p300 small interfering RNA (siRNA) transfection, p300 overexpression, or incubation with the p300 inhibitor curcumin. Histone H2AX phosphorylation and lysine acetylation were examined for oxidative DNA damage and p300 activation. Screening for transcription factors was performed with the Luminex system. Alterations of selected transcription factors were validated. mRNA expression of p300, endothelin-1 (ET-1), vascular endothelial growth factor (VEGF), and fibronectin (FN) and its splice variant EDB(+)FN and FN protein production were analyzed. HUVECs in 25 mmol/l glucose showed increased p300 production accompanied by increased binding of p300 to ET-1 and FN promoters, augmented histone acetylation, H2AX phosphorylation, activation of multiple transcription factors, and increased mRNA expression of vasoactive factors and ECM proteins. p300 overexpression showed a glucose-like effect on the mRNA expression of ET-1, VEGF, and FN. Furthermore, siRNA-mediated p300 blockade or chemical inhibitor of p300 prevented such glucose-induced changes. Similar mRNA upregulation was also seen in the organ culture of vascular tissues, which was prevented by p300 siRNA transfection. Data from these studies suggest that glucose-induced p300 upregulation is an important upstream epigenetic mechanism regulating gene expression of vasoactive factors and ECM proteins in endothelial cells and is a potential therapeutic target for diabetic complications.

  10. Cyclin D1 represses gluconeogenesis via inhibition of the transcriptional coactivator PGC1α.

    PubMed

    Bhalla, Kavita; Liu, Wan-Ju; Thompson, Keyata; Anders, Lars; Devarakonda, Srikripa; Dewi, Ruby; Buckley, Stephanie; Hwang, Bor-Jang; Polster, Brian; Dorsey, Susan G; Sun, Yezhou; Sicinski, Piotr; Girnun, Geoffrey D

    2014-10-01

    Hepatic gluconeogenesis is crucial to maintain normal blood glucose during periods of nutrient deprivation. Gluconeogenesis is controlled at multiple levels by a variety of signal transduction and transcriptional pathways. However, dysregulation of these pathways leads to hyperglycemia and type 2 diabetes. While the effects of various signaling pathways on gluconeogenesis are well established, the downstream signaling events repressing gluconeogenic gene expression are not as well understood. The cell-cycle regulator cyclin D1 is expressed in the liver, despite the liver being a quiescent tissue. The most well-studied function of cyclin D1 is activation of cyclin-dependent kinase 4 (CDK4), promoting progression of the cell cycle. We show here a novel role for cyclin D1 as a regulator of gluconeogenic and oxidative phosphorylation (OxPhos) gene expression. In mice, fasting decreases liver cyclin D1 expression, while refeeding induces cyclin D1 expression. Inhibition of CDK4 enhances the gluconeogenic gene expression, whereas cyclin D1-mediated activation of CDK4 represses the gluconeogenic gene-expression program in vitro and in vivo. Importantly, we show that cyclin D1 represses gluconeogenesis and OxPhos in part via inhibition of peroxisome proliferator-activated receptor γ coactivator-1α (PGC1α) activity in a CDK4-dependent manner. Indeed, we demonstrate that PGC1α is novel cyclin D1/CDK4 substrate. These studies reveal a novel role for cyclin D1 on metabolism via PGC1α and reveal a potential link between cell-cycle regulation and metabolic control of glucose homeostasis.

  11. 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.

  12. 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…

  13. Play Therapy in Elementary Schools

    ERIC Educational Resources Information Center

    Landreth, Garry L.; Ray, Dee C.; Bratton, Sue C.

    2009-01-01

    Because the child's world is a world of action and activity, play therapy provides the psychologist in elementary-school settings with an opportunity to enter the child's world. In the play therapy relationship, toys are like the child's words and play is the child's language. Therefore, children play out their problems, experiences, concerns, and…

  14. 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…

  15. Rough and Tumble Play 101

    ERIC Educational Resources Information Center

    Carlson, Frances

    2009-01-01

    Many people fear that play-fighting or rough and tumble play is the same as real fighting. There is also a fear that this rough play will become real fighting if allowed to continue. Most of all, parents and teachers fear that during the course of rough and tumble play a child may be hurt. To provide for and allow children to play rough without…

  16. Transcription coactivator peroxisome proliferator-activated receptor-binding protein/mediator 1 deficiency abrogates acetaminophen hepatotoxicity

    PubMed Central

    Jia, Yuzhi; Guo, Grace L.; Surapureddi, Sailesh; Sarkar, Joy; Qi, Chao; Guo, Dongsheng; Xia, Jun; Kashireddi, Papreddy; Yu, Songtao; Cho, Young-Wook; Rao, M. Sambasiva; Kemper, Byron; Ge, Kai; Gonzalez, Frank J.; Reddy, Janardan K.

    2005-01-01

    Peroxisome proliferator-activated receptor-binding protein (PBP), also known as thyroid hormone receptor-associated protein 220/vitamin D receptor-interacting protein 205/mediator 1, an anchor for multisubunit mediator transcription complex, functions as a transcription coactivator for nuclear receptors. Disruption of the PBP gene results in embryonic lethality around embryonic day 11.5 by affecting placental and multiorgan development. Here, we report that targeted deletion of PBP in liver parenchymal cells (PBPLiv-/-) results in the abrogation of hypertrophic and hyperplastic influences in liver mediated by constitutive androstane receptor (CAR) ligands phenobarbital (PB) and 1,4-bis-[2-(3,5-dichloropyridyloxy)]benzene, and of acetaminophen-induced hepatotoxicity. CAR interacts with the two nuclear receptor-interacting LXXLL (L, leucine; X, any amino acid) motifs in PBP in a ligand-dependent manner. We also show that PBP interacts with the C-terminal portion of CAR, suggesting that PBP is involved in the regulation of CAR function. Although the full-length PBP only minimally increased CAR transcriptional activity, a truncated form of PBP (amino acids 487-735) functioned as a dominant negative repressor, establishing that PBP functions as a coactivator for CAR. A reduction in CAR mRNA and protein level observed in PBPLiv-/- mouse liver suggests that PBP may regulate hepatic CAR expression. PBP-deficient hepatocytes in liver failed to reveal PB-dependent translocation of CAR to the nucleus. Adenoviral reconstitution of PBP in PBPLiv-/- mouse livers restored PB-mediated nuclear translocation of CAR as well as inducibility of CYP1A2, CYP2B10, CYP3A11, and CYP7A1 expression. We conclude that transcription coactivator PBP/TRAP220/MED1 is involved in the regulation of hepatic CAR function and that PBP deficiency in liver abrogates acetaminophen hepatotoxicity. PMID:16109766

  17. Runx1 regulation of Pu.1 corepressor/coactivator exchange identifies specific molecular targets for leukemia differentiation therapy.

    PubMed

    Gu, Xiaorong; Hu, Zhenbo; Ebrahem, Quteba; Crabb, John S; Mahfouz, Reda Z; Radivoyevitch, Tomas; Crabb, John W; Saunthararajah, Yogen

    2014-05-23

    Gene activation requires cooperative assembly of multiprotein transcription factor-coregulator complexes. Disruption to cooperative assemblage could underlie repression of tumor suppressor genes in leukemia cells. Mechanisms of cooperation and its disruption were therefore examined for PU.1 and RUNX1, transcription factors that cooperate to activate hematopoietic differentiation genes. PU.1 is highly expressed in leukemia cells, whereas RUNX1 is frequently inactivated by mutation or translocation. Thus, coregulator interactions of Pu.1 were examined by immunoprecipitation coupled with tandem mass spectrometry/Western blot in wild-type and Runx1-deficient hematopoietic cells. In wild-type cells, the NuAT and Baf families of coactivators coimmunoprecipitated with Pu.1. Runx1 deficiency produced a striking switch to Pu.1 interaction with the Dnmt1, Sin3A, Nurd, CoRest, and B-Wich corepressor families. Corepressors of the Polycomb family, which are frequently inactivated by mutation or deletion in myeloid leukemia, did not interact with Pu.1. The most significant gene ontology association of Runx1-Pu.1 co-bound genes was with macrophages, therefore, functional consequences of altered corepressor/coactivator exchange were examined at Mcsfr, a key macrophage differentiation gene. In chromatin immunoprecipitation analyses, high level Pu.1 binding to the Mcsfr promoter was not decreased by Runx1 deficiency. However, the Pu.1-driven shift from histone repression to activation marks at this locus, and terminal macrophage differentiation, were substantially diminished. DNMT1 inhibition, but not Polycomb inhibition, in RUNX1-translocated leukemia cells induced terminal differentiation. Thus, RUNX1 and PU.1 cooperate to exchange corepressors for coactivators, and the specific corepressors recruited to PU.1 as a consequence of RUNX1 deficiency could be rational targets for leukemia differentiation therapy.

  18. Transcriptional Regulation in Saccharomyces cerevisiae: Transcription Factor Regulation and Function, Mechanisms of Initiation, and Roles of Activators and Coactivators

    PubMed Central

    Hahn, Steven; Young, Elton T.

    2011-01-01

    Here we review recent advances in understanding the regulation of mRNA synthesis in Saccharomyces cerevisiae. Many fundamental gene regulatory mechanisms have been conserved in all eukaryotes, and budding yeast has been at the forefront in the discovery and dissection of these conserved mechanisms. Topics covered include upstream activation sequence and promoter structure, transcription factor classification, and examples of regulated transcription factor activity. We also examine advances in understanding the RNA polymerase II transcription machinery, conserved coactivator complexes, transcription activation domains, and the cooperation of these factors in gene regulatory mechanisms. PMID:22084422

  19. Play, Play Therapy, Play Research. Proceedings of the International Symposium (Amsterdam, the Netherlands, September 1985).

    ERIC Educational Resources Information Center

    Kooij, Rimmert van der; Hellendoorn, Joop

    After an introduction which briefly discusses emotional, therapeutic, phenomenological, cognitive, and developmental perspectives on play, this volume presents the complete texts of all the main lectures and a few short papers that were given at the International Symposium on Play, Play Therapy, and Play Research. Papers in part 1 concern certain…

  20. LINE-1 ORF-1p functions as a novel androgen receptor co-activator and promotes the growth of human prostatic carcinoma cells.

    PubMed

    Lu, Yinying; Feng, Fan; Yang, Yutao; Gao, Xudong; Cui, Jiajun; Zhang, Chuanfu; Zhang, Fan; Xu, Zhongxian; Qv, Jianhui; Wang, Chunping; Zeng, Zhen; Zhu, Yunfeng; Yang, Yongping

    2013-02-01

    Widespread interest in the mechanism of transcriptional regulation by the androgen receptor (AR) has been stimulated by the finding that AR signaling is critically important in the progression of human prostate cancers. Co-factors, the co-repressors, or the co-activators are responsible for the regulation of AR activation. The pro-oncogene human Long Interspersed Nucleotide acid Element-1 (LINE-1) encodes LINE-1 ORF-1p and plays important roles in the development and progression of several human carcinomas. In this study, the results showed that LINE-1 ORF-1p increased the AR transcriptional activity and in turn enhanced the expression of prostate specific antigen (PSA) in the presence of R1881. A physical protein-protein interaction between the AR signaling and the LINE-1 ORF-1p was identified by the immunoprecipitation assays and GST pull-down assays. Furthermore, LINE-1 ORF-1p would function as a novel AR positive co-regulator through modulating its cytoplasm/nucleus translocation and the recruitment to the androgen response element in the PSA gene promoter. Our date also showed that the LINE-1 ORF-1p promoted the proliferation and anchor-independent growth of LNCaP (ligand dependent) and PC-3 (ligand independent) human prostatic carcinoma cells. By investigating a novel role of the LINE-1 ORF-1p in the androgen/androgen receptor signaling pathway regulation, our study identifies that LINE-1 ORF-1p may be a novel AR co-regulator and molecular target for human prostate carcinoma therapy.

  1. 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

  2. Renal proximal tubule Na,K-ATPase is controlled by CREB-regulated transcriptional coactivators as well as salt-inducible kinase 1.

    PubMed

    Taub, Mary; Garimella, Sudha; Kim, Dongwook; Rajkhowa, Trivikram; Cutuli, Facundo

    2015-12-01

    Sodium reabsorption by the kidney is regulated by locally produced natriuretic and anti-natriuretic factors, including dopamine and norepinephrine, respectively. Previous studies indicated that signaling events initiated by these natriuretic and anti-natriuretic factors achieve their effects by altering the phosphorylation of Na,K-ATPase in the renal proximal tubule, and that protein kinase A (PKA) and calcium-mediated signaling pathways are involved. The same signaling pathways also control the transcription of the Na,K-ATPase β subunit gene atp1b1 in renal proximal tubule cells. In this report, evidence is presented that (1) both the recently discovered cAMP-regulated transcriptional coactivators (CRTCs) and salt-inducible kinase 1 (SIK1) contribute to the transcriptional regulation of atp1b1 in renal proximal tubule (RPT) cells and (2) renal effectors, including norepinephrine, dopamine, prostaglandins, and sodium, play a role. Exogenously expressed CRTCs stimulate atp1b1 transcription. Evidence for a role of endogenous CRTCs includes the loss of transcriptional regulation of atp1b1 by a dominant-negative CRTC, as well as by a CREB mutant, with an altered CRTC binding site. In a number of experimental systems, SIK phosphorylates CRTCs, which are then sequestered in the cytoplasm, preventing their nuclear effects. Consistent with such a role of SIK in primary RPT cells, atp1b1 transcription increased in the presence of a dominant-negative SIK1, and in addition, regulation by dopamine, norepinephrine, and monensin was disrupted by a dominant-negative SIK1. These latter observations can be explained if SIK1 is phosphorylated and inactivated in the presence of these renal effectors. Our results support the hypothesis that Na,K-ATPase in the renal proximal tubule is regulated at the transcriptional level via SIK1 and CRTCs by renal effectors, in addition to the previously reported control of the phosphorylation of Na,K-ATPase.

  3. 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…

  4. "Normal" Childhood Sexual Play and Games: Differentiating Play from Abuse.

    ERIC Educational Resources Information Center

    Lamb, Sharon; Coakley, Mary

    1993-01-01

    A survey of 128 undergraduate female students indicated that 44% had experienced cross-gender sexual play as children, which was often seen as involving persuasion, manipulation, or coercion. A typology of six kinds of sexual play experiences was derived. Discussion focuses on the differentiation of childhood sexual abuse from play and gender…

  5. 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

  6. Play technique in psychodynamic psychotherapy.

    PubMed

    Yanof, Judith A

    2013-04-01

    Imaginary play is often a child's best way of communicating affects, fantasies, and internal states. In play children are freer to express their forbidden and conflicted thoughts. Consequently, one of the best ways for the therapist to enter the child's world is to do so from within the displacement of the play process. For children who cannot play, the therapist's goal is to teach the child to use play as a means of communication and to create meaning. This article present clinical examples to illustrate how the author uses play in the clinical situation.

  7. 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.

  8. Synergistic Co-activation Increases the Extent of Mechanical Interaction between Rat Ankle Plantar-Flexors

    PubMed Central

    Tijs, Chris; van Dieën, Jaap H.; Baan, Guus C.; Maas, Huub

    2016-01-01

    Force transmission between rat ankle plantar-flexors has been found for physiological muscle lengths and relative positions, but only with all muscles maximally activated. The aims of this study were to assess intermuscular mechanical interactions between ankle plantar-flexors during (i) fully passive conditions, (ii) excitation of soleus (SO), (iii) excitation of lateral gastrocnemius (LG), and (iv) during co-activation of SO, and LG (SO&LG). We assessed effects of proximal lengthening of LG and plantaris (PL) muscles (i.e., simulating knee extension) on forces exerted at the distal SO tendon (FSO) and on the force difference between the proximal and distal LG+PL tendons (ΔFLG+PL) of the rat. LG+PL lengthening increased FSO to a larger extent (p = 0.017) during LG excitation (0.0026 N/mm) than during fully passive conditions (0.0009 N/mm). Changes in FSO in response to LG+PL lengthening were lower (p = 0.002) during SO only excitation (0.0056 N/mm) than during SO&LG excitation (0.0101 N/mm). LG+PL lengthening changed ΔFLG+PL to a larger extent (p = 0.007) during SO excitation (0.0211 N/mm) than during fully passive conditions (0.0157 N/mm). In contrast, changes in ΔFLG+PL in response to LG+PL lengthening during LG excitation (0.0331 N/mm) were similar (p = 0.161) to that during SO&LG excitation (0.0370 N/mm). In all conditions, changes of FSO were lower than those of ΔFLG+PL. This indicates that muscle forces were transmitted not only between LG+PL and SO, but also between LG+PL and other surrounding structures. In addition, epimuscular myofascial force transmission between rat ankle plantar-flexors was enhanced by muscle activation. However, the magnitude of this interaction was limited. PMID:27708589

  9. 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

  10. 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)

  11. Safety Play Surfaces Buying Guide.

    ERIC Educational Resources Information Center

    Morris, Susan

    1990-01-01

    Describes standards for playing surfaces and characteristics of play surfaces made of organic loose material, inorganic loose material, and compact materials. Necessary site preparation is discussed. An extensive, annotated list of manufacturers of surfaces is included. (DR)

  12. 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 ...

  13. 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

  14. Play Therapy: Basics and Beyond.

    ERIC Educational Resources Information Center

    Kottman, Terry

    This book provides an atheoretical orientation to basic concepts involved in play therapy and an introduction to different skills used in play therapy. The demand for mental professionals and school counselors who have training and expertise in using play as a therapeutic tool when working with children has increased tremendously. In response to…

  15. 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…

  16. The Importance of Being Playful.

    ERIC Educational Resources Information Center

    Bodrova, Elena; Leong, Deborah J.

    2003-01-01

    Recent research provides evidence of the strong connections between quality of play in preschool years and children's readiness for school instruction. Mature play, characterized by imaginary situations, multiple roles, clearly defined rules, flexible themes, language development, length of play, helps students' cognitive development. (Contains 12…

  17. 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…

  18. 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…

  19. 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…

  20. 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…

  1. The transcriptional co-activator LEDGF/p75 displays a dynamic scan-and-lock mechanism for chromatin tethering

    PubMed Central

    Hendrix, Jelle; Gijsbers, Rik; De Rijck, Jan; Voet, Arnout; Hotta, Jun-ichi; McNeely, Melissa; Hofkens, Johan; Debyser, Zeger; Engelborghs, Yves

    2011-01-01

    Nearly all cellular and disease related functions of the transcriptional co-activator lens epithelium-derived growth factor (LEDGF/p75) involve tethering of interaction partners to chromatin via its conserved integrase binding domain (IBD), but little is known about the mechanism of in vivo chromatin binding and tethering. In this work we studied LEDGF/p75 in real-time in living HeLa cells combining different quantitative fluorescence techniques: spot fluorescence recovery after photobleaching (sFRAP) and half-nucleus fluorescence recovery after photobleaching (hnFRAP), continuous photobleaching, fluorescence correlation spectroscopy (FCS) and an improved FCS method to study diffusion dependence of chromatin binding, tunable focus FCS. LEDGF/p75 moves about in nuclei of living cells in a chromatin hopping/scanning mode typical for transcription factors. The PWWP domain of LEDGF/p75 is necessary, but not sufficient for in vivo chromatin binding. After interaction with HIV-1 integrase via its IBD, a general protein–protein interaction motif, kinetics of LEDGF/p75 shift to 75-fold larger affinity for chromatin. The PWWP is crucial for locking the complex on chromatin. We propose a scan-and-lock model for LEDGF/p75, unifying paradoxical notions of transcriptional co-activation and lentiviral integration targeting. PMID:20974633

  2. Quantifying thigh muscle co-activation during isometric knee extension contractions: within- and between-session reliability.

    PubMed

    Katsavelis, Dimitrios; Threlkeld, A Joseph

    2014-08-01

    Muscle co-activation around the knee is important during ambulation and balance. The wide range of methodological approaches for the quantification of co-activation index (CI) makes comparisons across studies and populations difficult. The present study determined within- and between-session reliability of different methodological approaches for the quantification of the CI of the knee extensor and flexor muscles during maximum voluntary isometric contractions (MVICs). Eight healthy volunteers participated in two repeated testing sessions. A series of knee extension MVICs of the dominant leg with concomitant torque and electromyographic (EMG) recordings were captured. CI was calculated utilizing different analytical approaches. Intraclass correlation coefficient (ICC) showed that within-session measures displayed higher reliability (ICC>0.861) and lower variability (Coefficient of variation; CV<21.8%) than between-session measures (ICC<0.645; CV>24.2%). A selection of a 500ms or larger window of RMS EMG activity around the PT delivered more reliable and less variable results than other approaches. Our findings suggest that the CI can provide a reliable measure for comparisons among conditions and is best utilized for within-session experimental designs.

  3. 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

  4. 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}.

  5. 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.

  6. Pain as a reward: changing the meaning of pain from negative to positive co-activates opioid and cannabinoid systems.

    PubMed

    Benedetti, Fabrizio; Thoen, Wilma; Blanchard, Catherine; Vighetti, Sergio; Arduino, Claudia

    2013-03-01

    Pain is a negative emotional experience that is modulated by a variety of psychological factors through different inhibitory systems. For example, endogenous opioids and cannabinoids have been found to be involved in stress and placebo analgesia. Here we show that when the meaning of the pain experience is changed from negative to positive through verbal suggestions, the opioid and cannabinoid systems are co-activated and these, in turn, increase pain tolerance. We induced ischemic arm pain in healthy volunteers, who had to tolerate the pain as long as possible. One group was informed about the aversive nature of the task, as done in any pain study. Conversely, a second group was told that the ischemia would be beneficial to the muscles, thus emphasizing the usefulness of the pain endurance task. We found that in the second group pain tolerance was significantly higher compared to the first one, and that this effect was partially blocked by the opioid antagonist naltrexone alone and by the cannabinoid antagonist rimonabant alone. However, the combined administration of naltrexone and rimonabant antagonized the increased tolerance completely. Our results indicate that a positive approach to pain reduces the global pain experience through the co-activation of the opioid and cannabinoid systems. These findings may have a profound impact on clinical practice. For example, postoperative pain, which means healing, can be perceived as less unpleasant than cancer pain, which means death. Therefore, the behavioral and/or pharmacological manipulation of the meaning of pain can represent an effective approach to pain management.

  7. 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

  8. Downregulation of steroid receptor coactivator-2 modulates estrogen-responsive genes and stimulates proliferation of mcf-7 breast cancer cells.

    PubMed

    Fenne, Ingvild S; Helland, Thomas; Flågeng, Marianne H; Dankel, Simon N; Mellgren, Gunnar; Sagen, Jørn V

    2013-01-01

    The p160/Steroid Receptor Coactivators SRC-1, SRC-2/GRIP1, and SRC-3/AIB1 are important regulators of Estrogen Receptor alpha (ERα) activity. However, whereas the functions of SRC-1 and SRC-3 in breast tumourigenesis have been extensively studied, little is known about the role of SRC-2. Previously, we reported that activation of the cAMP-dependent protein kinase, PKA, facilitates ubiquitination and proteasomal degradation of SRC-2 which in turn leads to inhibition of SRC-2-coactivation of ERα and changed expression of the ERα target gene, pS2. Here we have characterized the global program of transcription in SRC-2-depleted MCF-7 breast cancer cells using short-hairpin RNA technology, and in MCF-7 cells exposed to PKA activating agents. In order to identify genes that may be regulated through PKA-induced downregulation of SRC-2, overlapping transcriptional targets in response to the respective treatments were characterized. Interestingly, we observed decreased expression of several breast cancer tumour suppressor genes (e.g., TAGLN, EGR1, BCL11b, CAV1) in response to both SRC-2 knockdown and PKA activation, whereas the expression of a number of other genes implicated in cancer progression (e.g., RET, BCAS1, TFF3, CXCR4, ADM) was increased. In line with this, knockdown of SRC-2 also stimulated proliferation of MCF-7 cells. Together, these results suggest that SRC-2 may have an antiproliferative function in breast cancer cells.

  9. 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

  10. SCFCdc4 acts antagonistically to the PGC-1alpha transcriptional coactivator by targeting it for ubiquitin-mediated proteolysis.

    PubMed

    Olson, Brian L; Hock, M Benjamin; Ekholm-Reed, Susanna; Wohlschlegel, James A; Dev, Kumlesh K; Kralli, Anastasia; Reed, Steven I

    2008-01-15

    Peroxisome proliferator-activated receptor gamma (PPARgamma) coactivator-1alpha (PGC-1alpha) is a highly regulated transcriptional coactivator that coordinates energy metabolism in mammals. Misregulation of PGC-1alpha has been implicated in the pathogenesis of several human diseases, including diabetes, obesity, and neurological disorders. We identified SCF(Cdc4) as an E3 ubiquitin ligase that regulates PGC-1alpha through ubiquitin-mediated proteolysis. PGC-1alpha contains two Cdc4 phosphodegrons that bind Cdc4 when phosphorylated by Glycogen Synthase Kinase 3beta (GSK3beta) and p38 MAPK, leading to SCF(Cdc4)-dependent ubiquitylation and proteasomal degradation of PGC-1alpha. Furthermore, SCF(Cdc4) negatively regulates PGC-1alpha-dependent transcription. We demonstrate that RNAi-mediated reduction of Cdc4 in primary neurons results in an increase of endogenous PGC-1alpha protein, while ectopic expression of Cdc4 leads to a reduction of endogenous PGC-1alpha protein. Finally, under conditions of oxidative stress in neurons, Cdc4 levels are decreased, leading to an increase in PGC-1alpha protein and PGC-1alpha-dependent transcription. These results suggest that attenuation of SCF(Cdc4)-dependent proteasomal degradation of PGC-1alpha has a role in mediating the PGC-1alpha-dependent transcriptional response to oxidative stress.

  11. Mice lacking the transcriptional coactivator PGC-1α exhibit alterations in inhibitory synaptic transmission in the motor cortex.

    PubMed

    Dougherty, S E; Bartley, A F; Lucas, E K; Hablitz, J J; Dobrunz, L E; Cowell, R M

    2014-06-20

    Peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) is a transcriptional coactivator known to regulate gene programs in a cell-specific manner in energy-demanding tissues, and its dysfunction has been implicated in numerous neurological and psychiatric disorders. Previous work from the Cowell laboratory indicates that PGC-1α is concentrated in inhibitory interneurons and is required for the expression of the calcium buffer parvalbumin (PV) in the cortex; however, the impact of PGC-1α deficiency on inhibitory neurotransmission in the motor cortex is not known. Here, we show that mice lacking PGC-1α exhibit increased amplitudes and decreased frequency of spontaneous inhibitory postsynaptic currents in layer V pyramidal neurons. Upon repetitive train stimulation at the gamma frequency, decreased GABA release is observed. Furthermore, PV-positive interneurons in PGC-1α -/- mice display reductions in intrinsic excitability and excitatory input without changes in gross interneuron morphology. Taken together, these data show that PGC-1α is required for normal inhibitory neurotransmission and cortical PV-positive interneuron function. Given the pronounced motor dysfunction in PGC-1α -/- mice and the essential role of PV-positive interneurons in maintenance of cortical excitatory:inhibitory balance, it is possible that deficiencies in PGC-1α expression could contribute to cortical hyperexcitability and motor abnormalities in multiple neurological disorders.

  12. Metformin inhibits hepatocellular glucose, lipid and cholesterol biosynthetic pathways by transcriptionally suppressing steroid receptor coactivator 2 (SRC-2).

    PubMed

    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

  13. 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

  14. 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

  15. 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)

  16. Toy play, play tempo, and reaction to frustration in infants.

    PubMed

    Longo, J; Harvey, A; Wilson, S; Deni, R

    1982-08-01

    Measures of toy play including duration and tempo of play were obtained for a combined sample of 7 male and 5 female infants 22 to 26 mo. of age. Additional measures of reaction to frustration were obtained during a second session where toys were placed out of reach of the subjects. Measures of frustration included crying, squirm/escape attempts, and non-crying vocalizations. Several correlations between toy play and reaction to frustration were found and were indicative of a general relationship between response persistence during play and attempts to escape from the frustrating situation. PMID:7133910

  17. Play and the Peer Culture: Play Styles and Object Use.

    ERIC Educational Resources Information Center

    Elgas, Peggy M.; And Others

    1988-01-01

    Findings suggested that: (1) peer culture is not a unitary whole but rather a differentiated social system comprised of various groups and different types of players; (2) objects play an important role in peer culture as entry vehicles and social markers; and (3) play periods are social arenas in which the dynamics of the peer culture are enacted.…

  18. 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…

  19. 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,…

  20. Children's Play in Diverse Cultures. Children's Play in Society Series.

    ERIC Educational Resources Information Center

    Roopnarine, Jaipaul L., Ed.; And Others

    This book illuminates play as a universal and culture-specific activity. It provides needed information about the behavior of children in diverse cultural contexts as well as about the play of children in unassimilated cultural or subcultural contexts. It offers readers the opportunity to develop greater sensitivity to and better understanding of…

  1. Partners in Play: An Adlerian Approach to Play Therapy.

    ERIC Educational Resources Information Center

    Kottman, Terry

    In response to increasing concern about the mental health of young children, the field of play therapy is expanding rapidly. This book explains the principles of Adlerian therapy and offers step-by-step instructions on how to integrate these concepts and techniques into the practice of play therapy. Ideas are presented on how to build an…

  2. The Importance of Play: Why Children Need to Play

    ERIC Educational Resources Information Center

    Bodrova, Elena; Leong, Deborah J.

    2005-01-01

    In this article, the authors discuss the important role of dramatic ("pretend") play in early childhood with increasing emphasis at school on developing academic skills in children at younger and younger ages. Play is especially beneficial to children's learning when it reaches a certain degree of sophistication. In other words, "unproductive"…

  3. Playing It Safe: Risk Management for Games Play.

    ERIC Educational Resources Information Center

    Halliday, Nancy

    1996-01-01

    Considering the players, the game, and the environment in which games are played can make games play at camp safer, more successful, and more enjoyable. Presents factors concerning the players, the game, roughhousing, excessive competitiveness, the environment, space, boundaries, weather, time, and overall game objectives that need to be…

  4. 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…

  5. Symbolic play and language development.

    PubMed

    Orr, Edna; Geva, Ronny

    2015-02-01

    Symbolic play and language are known to be highly interrelated, but the developmental process involved in this relationship is not clear. Three hypothetical paths were postulated to explore how play and language drive each other: (1) direct paths, whereby initiation of basic forms in symbolic action or babbling, will be directly related to all later emerging language and motor outputs; (2) an indirect interactive path, whereby basic forms in symbolic action will be associated with more complex forms in symbolic play, as well as with babbling, and babbling mediates the relationship between symbolic play and speech; and (3) a dual path, whereby basic forms in symbolic play will be associated with basic forms of language, and complex forms of symbolic play will be associated with complex forms of language. We micro-coded 288 symbolic vignettes gathered during a yearlong prospective bi-weekly examination (N=14; from 6 to 18 months of age). Results showed that the age of initiation of single-object symbolic play correlates strongly with the age of initiation of later-emerging symbolic and vocal outputs; its frequency at initiation is correlated with frequency at initiation of babbling, later-emerging speech, and multi-object play in initiation. Results support the notion that a single-object play relates to the development of other symbolic forms via a direct relationship and an indirect relationship, rather than a dual-path hypothesis. PMID:25658200

  6. 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…

  7. Energy-sensing Factors Coactivator Peroxisome Proliferator-activated Receptor γ Coactivator 1-α (PGC-1α) and AMP-activated Protein Kinase Control Expression of Inflammatory Mediators in Liver

    PubMed Central

    Buler, Marcin; Aatsinki, Sanna-Mari; Skoumal, Réka; Komka, Zsolt; Tóth, Miklós; Kerkelä, Risto; Georgiadi, Anastasia; Kersten, Sander; Hakkola, Jukka

    2012-01-01

    Obesity and insulin resistance are associated with chronic, low grade inflammation. Moreover, regulation of energy metabolism and immunity are highly integrated. We hypothesized that energy-sensitive coactivator peroxisome proliferator-activated receptor γ coactivator 1-α (PGC-1α) and AMP-activated protein kinase (AMPK) may modulate inflammatory gene expression in liver. Microarray analysis revealed that PGC-1α up-regulated expression of several cytokines and cytokine receptors, including interleukin 15 receptor α (IL15Rα) and, even more importantly, anti-inflammatory interleukin 1 receptor antagonist (IL1Rn). Overexpression of PGC-1α and induction of PGC-1α by fasting, physical exercise, glucagon, or cAMP was associated with increased IL1Rn mRNA and protein expression in hepatocytes. Knockdown of PGC-1α by siRNA down-regulated cAMP-induced expression of IL1Rn in mouse hepatocytes. Furthermore, knockdown of peroxisome proliferator-activated receptor α (PPARα) attenuated IL1Rn induction by PGC-1α. Overexpression of PGC-1α, at least partially through IL1Rn, suppressed interleukin 1β-induced expression of acute phase proteins, C-reactive protein, and haptoglobin. Fasting and exercise also induced IL15Rα expression, whereas glucagon and cAMP resulted in reduction in IL15Rα mRNA levels. Finally, AMPK activator metformin and adenoviral overexpression of AMPK up-regulated IL1Rn and down-regulated IL15Rα in primary hepatocytes. We conclude that PGC-1α and AMPK alter inflammatory gene expression in liver and thus integrate energy homeostasis and inflammation. Induction of IL1Rn by PGC-1α and AMPK may be involved in the beneficial effects of exercise and caloric restriction and putative anti-inflammatory effects of metformin. PMID:22117073

  8. Energy-sensing factors coactivator peroxisome proliferator-activated receptor γ coactivator 1-α (PGC-1α) and AMP-activated protein kinase control expression of inflammatory mediators in liver: induction of interleukin 1 receptor antagonist.

    PubMed

    Buler, Marcin; Aatsinki, Sanna-Mari; Skoumal, Réka; Komka, Zsolt; Tóth, Miklós; Kerkelä, Risto; Georgiadi, Anastasia; Kersten, Sander; Hakkola, Jukka

    2012-01-13

    Obesity and insulin resistance are associated with chronic, low grade inflammation. Moreover, regulation of energy metabolism and immunity are highly integrated. We hypothesized that energy-sensitive coactivator peroxisome proliferator-activated receptor γ coactivator 1-α (PGC-1α) and AMP-activated protein kinase (AMPK) may modulate inflammatory gene expression in liver. Microarray analysis revealed that PGC-1α up-regulated expression of several cytokines and cytokine receptors, including interleukin 15 receptor α (IL15Rα) and, even more importantly, anti-inflammatory interleukin 1 receptor antagonist (IL1Rn). Overexpression of PGC-1α and induction of PGC-1α by fasting, physical exercise, glucagon, or cAMP was associated with increased IL1Rn mRNA and protein expression in hepatocytes. Knockdown of PGC-1α by siRNA down-regulated cAMP-induced expression of IL1Rn in mouse hepatocytes. Furthermore, knockdown of peroxisome proliferator-activated receptor α (PPARα) attenuated IL1Rn induction by PGC-1α. Overexpression of PGC-1α, at least partially through IL1Rn, suppressed interleukin 1β-induced expression of acute phase proteins, C-reactive protein, and haptoglobin. Fasting and exercise also induced IL15Rα expression, whereas glucagon and cAMP resulted in reduction in IL15Rα mRNA levels. Finally, AMPK activator metformin and adenoviral overexpression of AMPK up-regulated IL1Rn and down-regulated IL15Rα in primary hepatocytes. We conclude that PGC-1α and AMPK alter inflammatory gene expression in liver and thus integrate energy homeostasis and inflammation. Induction of IL1Rn by PGC-1α and AMPK may be involved in the beneficial effects of exercise and caloric restriction and putative anti-inflammatory effects of metformin.

  9. Risk analysis of exploration plays

    SciTech Connect

    Rose, P.R.

    1996-08-01

    The most difficult and crucial decision in petroleum exploration is not which prospect to drill, but rather, which new play to enter. Such a decision, whether ultimately profitable or not, commits the Organization to years of involvement, expenditures of $millions, and hundreds of man-years of effort. Even though uncertainties and risks are high, organizations commonly make the new-play decision in a disjointed, non-analytic, even superficial way. The economic consequences of a bad play choice can be disastrous. Using established principles of prospect risk analysis, modern petroleum exploration organizations routinely assign economic value to individual prospects, but they actually operate via exploration programs in plays and trends. Accordingly, the prospect is the economic unit of exploration, whereas the play is the operational unit. Plays can be successfully analyzed as full-cycle economic risk ventures, however, using many principles of prospect risk analysis. Economic measures such as Expected Present Value, DCFROR, etc. apply equally to plays or prospects. The predicted field-size distribution of the play is analogous to the forecast prospect reserves distribution, Economic truncation applies to both. Variance of play reserves is usually much greater than for prospect reserves. Geologic chance factors such as P{sub reservoir}, P{sub generation}, etc., must be distinguished as independent or shared among prospects in the play, so they should be defined so as to apply equally to the play and to its constituent prospects. They are analogous to multiple objectives on a prospect, and are handled differently in performing the risk analysis.

  10. Risk analysis of exploration plays

    SciTech Connect

    Rose, P.R.

    1996-06-01

    The most difficult and crucial decision in petroleum exploration is not which prospect to drill, but rather, which new play to enter. Such a decision, whether ultimately profitable or not, commits the Organization to years of involvement, expenditures of $millions, and hundreds of man-years of effort. Even though uncertainties and risks are high, organizations commonly make the new-play decision in a disjointed, non-analytic, even superficial way. The economic consequences of a bad play choice can be disastrous. Using established principles of prospect risk analysis, modern petroleum exploration organizations routinely assign economic value to individual prospects, but they actually operate via exploration programs in plays and trends. Accordingly, the prospect is the economic unit of exploration, whereas the play is the operational unit. Plays can be successfully analyzed as full-cycle economic risk ventures, however, using many principles of prospect risk analysis. Economic measures such as Expected Present Value, DCFROR, etc. apply equally to plays or prospects. The predicted field-size distribution of the play is analogous to the forecast prospect reserves distribution. Economic truncation applies to both. Variance of play reserves is usually much greater than for prospect reserves. Geologic chance factors such as P{sub reservoir}, P{sub generation}, etc., must be distinguished as independent or shared among prospects in the play, so they should be defined so as to apply equally to the play and to its constituent prospects. They are analogous to multiple objectives on a prospect, and are handled differently in performing the risk analysis.

  11. 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…

  12. 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…

  13. The Disruptive Child's Play Group.

    ERIC Educational Resources Information Center

    Bleck, Robert T.; Bleck, Bonnie L.

    1982-01-01

    Examined the effects of the Disruptive Child's Play Group (DCPG) on the self-concept of children with disruptive behavior problems. Results indicated that counselors using structured play can have positive effects on the attitudes of disruptive children. The DCPG significantly increased self-concept scores of disruptive children. (RC)

  14. 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…

  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. 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…

  17. 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…

  18. 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…

  19. 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…

  20. 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…

  1. 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…

  2. 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…

  3. 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…

  4. 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.

  5. The Social Competence of Play.

    ERIC Educational Resources Information Center

    Fein, Greta G.

    This is a study of how young children gain social competence through pretend play or role playing. Subjects were 38 Caucasian children (19 females, 19 males) who were observed at four ages: 12, 18, 24 and 30 months. The same set of toys, which included a doll, a saucepan, doll bottles, coffee mug, teacup, teaspoon, doll crib, blanket, toy phone…

  6. Child's Play Is Serious Business.

    ERIC Educational Resources Information Center

    McKimmey, Martha A.

    1993-01-01

    Play, long seen as an outlet for unused physical and emotional energy, and as a way of learning adult roles, is also recognized for its role in language development in children. Through play, children gain the skill to use symbols and representation for things and events in the environment, providing the basis of their further use of language.…

  7. 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…

  8. 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…

  9. 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…

  10. 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…

  11. Is hepatic lipogenesis fundamental for NAFLD/NASH? A focus on the nuclear receptor coactivator PGC-1β.

    PubMed

    Ducheix, Simon; Vegliante, Maria Carmela; Villani, Gaetano; Napoli, Nicola; Sabbà, Carlo; Moschetta, Antonio

    2016-10-01

    Non-alcoholic fatty liver diseases are the hepatic manifestation of metabolic syndrome. According to the classical pattern of NAFLD progression, de novo fatty acid synthesis has been incriminated in NAFLD progression. However, this hypothesis has been challenged by the re-evaluation of NAFLD development mechanisms together with the description of the role of lipogenic genes in NAFLD and with the recent observation that PGC-1β, a nuclear receptor/transcription factor coactivator involved in the transcriptional regulation of lipogenesis, displays protective effects against NAFLD/NASH progression. In this review, we focus on the implication of lipogenesis and triglycerides synthesis on the development of non-alcoholic fatty liver diseases and discuss the involvement of these pathways in the protective role of PGC-1β toward these hepatic manifestations.

  12. Identification of Small-Molecule Enhancers of Arginine Methylation Catalyzed by Coactivator-Associated Arginine Methyltransferase 1

    PubMed Central

    Castellano, Sabrina; Spannhoff, Astrid; Milite, Ciro; Dal Piaz, Fabrizio; Cheng, Donghang; Tosco, Alessandra; Viviano, Monica; Yamani, Abdellah; Cianciulli, Agostino; Sala, Marina; Cura, Vincent; Cavarelli, Jean; Novellino, Ettore; Mai, Antonello; Bedford, Mark T.; Sbardella, Gianluca

    2012-01-01

    Arginine methylation is a common post-translational modification that is crucial in modulating gene expression at multiple critical levels. The arginine methyltransferases (PRMTs) are envisaged as promising druggable targets but their role in physiological and pathological pathways is far from being clear, due to the limited number of modulators reported to date. In this effort, enzyme activators can be invaluable tools useful as gain-of-function reagents to interrogate the biological roles in cells and in vivo of PRMTs. Yet the identification of such molecules is rarely pursued. Herein we describe a series of aryl ureido acetamido indole carboxylates (dubbed “uracandolates”), able to increase the methylation of histone- (H3) or non-histone (polyadenylate-binding protein 1, PABP1) substrates induced by coactivator-associated arginine methyltransferase 1 (CARM1), both in in vitro and cellular settings. To the best of our knowledge, this is the first report of compounds acting as CARM1 activators. PMID:23095008

  13. Is hepatic lipogenesis fundamental for NAFLD/NASH? A focus on the nuclear receptor coactivator PGC-1β.

    PubMed

    Ducheix, Simon; Vegliante, Maria Carmela; Villani, Gaetano; Napoli, Nicola; Sabbà, Carlo; Moschetta, Antonio

    2016-10-01

    Non-alcoholic fatty liver diseases are the hepatic manifestation of metabolic syndrome. According to the classical pattern of NAFLD progression, de novo fatty acid synthesis has been incriminated in NAFLD progression. However, this hypothesis has been challenged by the re-evaluation of NAFLD development mechanisms together with the description of the role of lipogenic genes in NAFLD and with the recent observation that PGC-1β, a nuclear receptor/transcription factor coactivator involved in the transcriptional regulation of lipogenesis, displays protective effects against NAFLD/NASH progression. In this review, we focus on the implication of lipogenesis and triglycerides synthesis on the development of non-alcoholic fatty liver diseases and discuss the involvement of these pathways in the protective role of PGC-1β toward these hepatic manifestations. PMID:27522544

  14. The transcriptional coactivator PGC-1α is dispensable for chronic overload-induced skeletal muscle hypertrophy and metabolic remodeling.

    PubMed

    Pérez-Schindler, Joaquín; Summermatter, Serge; Santos, Gesa; Zorzato, Francesco; Handschin, Christoph

    2013-12-10

    Skeletal muscle mass loss and dysfunction have been linked to many diseases. Conversely, resistance exercise, mainly by activating mammalian target of rapamycin complex 1 (mTORC1), promotes skeletal muscle hypertrophy and exerts several therapeutic effects. Moreover, mTORC1, along with peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α), regulates skeletal muscle metabolism. However, it is unclear whether PGC-1α is required for skeletal muscle adaptations after overload. Here we show that although chronic overload of skeletal muscle via synergist ablation (SA) strongly induces hypertrophy and a switch toward a slow-contractile phenotype, these effects were independent of PGC-1α. In fact, SA down-regulated PGC-1α expression and led to a repression of energy metabolism. Interestingly, however, PGC-1α deletion preserved peak force after SA. Taken together, our data suggest that PGC-1α is not involved in skeletal muscle remodeling induced by SA.

  15. Cytoarchitectonic mapping of the human brain cerebellar nuclei in stereotaxic space and delineation of their co-activation patterns.

    PubMed

    Tellmann, Stefanie; Bludau, Sebastian; Eickhoff, Simon; Mohlberg, Hartmut; Minnerop, Martina; Amunts, Katrin

    2015-01-01

    The cerebellar nuclei are involved in several brain functions, including the modulation of motor and cognitive performance. To differentiate their participation in these functions, and to analyze their changes in neurodegenerative and other diseases as revealed by neuroimaging, stereotaxic maps are necessary. These maps reflect the complex spatial structure of cerebellar nuclei with adequate spatial resolution and detail. Here we report on the cytoarchitecture of the dentate, interposed (emboliform and globose) and fastigial nuclei, and introduce 3D probability maps in stereotaxic MNI-Colin27 space as a prerequisite for subsequent meta-analysis of their functional involvement. Histological sections of 10 human post mortem brains were therefore examined. Differences in cell density were measured and used to distinguish a dorsal from a ventral part of the dentate nucleus. Probabilistic maps were calculated, which indicate the position and extent of the nuclei in 3D-space, while considering their intersubject variability. The maps of the interposed and the dentate nuclei differed with respect to their interaction patterns and functions based on meta-analytic connectivity modeling and quantitative functional decoding, respectively. For the dentate nucleus, significant (p < 0.05) co-activations were observed with thalamus, supplementary motor area (SMA), putamen, BA 44 of Broca's region, areas of superior and inferior parietal cortex, and the superior frontal gyrus (SFG). In contrast, the interposed nucleus showed more limited co-activations with SMA, area 44, putamen, and SFG. Thus, the new stereotaxic maps contribute to analyze structure and function of the cerebellum. These maps can be used for anatomically reliable and precise identification of degenerative alteration in MRI-data of patients who suffer from various cerebellar diseases. PMID:26029057

  16. 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.

  17. 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

  18. Finerenone Impedes Aldosterone-dependent Nuclear Import of the Mineralocorticoid Receptor and Prevents Genomic Recruitment of Steroid Receptor Coactivator-1*

    PubMed Central

    Amazit, Larbi; Le Billan, Florian; Kolkhof, Peter; Lamribet, Khadija; Viengchareun, Say; Fay, Michel R.; Khan, Junaid A.; Hillisch, Alexander; Lombès, Marc; Rafestin-Oblin, Marie-Edith; Fagart, Jérôme

    2015-01-01

    Aldosterone regulates sodium homeostasis by activating the mineralocorticoid receptor (MR), a member of the nuclear receptor superfamily. Hyperaldosteronism leads todeleterious effects on the kidney, blood vessels, and heart. Although steroidal antagonists such as spironolactone and eplerenone are clinically useful for the treatment of cardiovascular diseases, they are associated with several side effects. Finerenone, a novel nonsteroidal MR antagonist, is presently being evaluated in two clinical phase IIb trials. Here, we characterized the molecular mechanisms of action of finerenone and spironolactone at several key steps of the MR signaling pathway. Molecular modeling and mutagenesis approaches allowed identification of Ser-810 and Ala-773 as key residues for the high MR selectivity of finerenone. Moreover, we showed that, in contrast to spironolactone, which activates the S810L mutant MR responsible for a severe form of early onset hypertension, finerenone displays strict antagonistic properties. Aldosterone-dependent phosphorylation and degradation of MR are inhibited by both finerenone and spironolactone. However, automated quantification of MR subcellular distribution demonstrated that finerenone delays aldosterone-induced nuclear accumulation of MR more efficiently than spironolactone. Finally, chromatin immunoprecipitation assays revealed that, as opposed to spironolactone, finerenone inhibits MR, steroid receptor coactivator-1, and RNA polymerase II binding at the regulatory sequence of the SCNN1A gene and also remarkably reduces basal MR and steroid receptor coactivator-1 recruitment, unraveling a specific and unrecognized inactivating mechanism on MR signaling. Overall, our data demonstrate that the highly potent and selective MR antagonist finerenone specifically impairs several critical steps of the MR signaling pathway and therefore represents a promising new generation MR antagonist. PMID:26203193

  19. Regulation of the transcriptional coactivator FHL2 licenses activation of the androgen receptor in castrate-resistant prostate cancer.

    PubMed

    McGrath, Meagan J; Binge, Lauren C; Sriratana, Absorn; Wang, Hong; Robinson, Paul A; Pook, David; Fedele, Clare G; Brown, Susan; Dyson, Jennifer M; Cottle, Denny L; Cowling, Belinda S; Niranjan, Birunthi; Risbridger, Gail P; Mitchell, Christina A

    2013-08-15

    It is now clear that progression from localized prostate cancer to incurable castrate-resistant prostate cancer (CRPC) is driven by continued androgen receptor (AR), signaling independently of androgen. Thus, there remains a strong rationale to suppress AR activity as the single most important therapeutic goal in CRPC treatment. Although the expression of ligand-independent AR splice variants confers resistance to AR-targeted therapy and progression to lethal castrate-resistant cancer, the molecular regulators of AR activity in CRPC remain unclear, in particular those pathways that potentiate the function of mutant AR in CRPC. Here, we identify FHL2 as a novel coactivator of ligand-independent AR variants that are important in CRPC. We show that the nuclear localization of FHL2 and coactivation of the AR is driven by calpain cleavage of the cytoskeletal protein filamin, a pathway that shows differential activation in prostate epithelial versus prostate cancer cell lines. We further identify a novel FHL2-AR-filamin transcription complex, revealing how deregulation of this axis promotes the constitutive, ligand-independent activation of AR variants, which are present in CRPC. Critically, the calpain-cleaved filamin fragment and FHL2 are present in the nucleus only in CRPC and not benign prostate tissue or localized prostate cancer. Thus, our work provides mechanistic insight into the enhanced AR activation, most notably of the recently identified AR variants, including AR-V7 that drives CRPC progression. Furthermore, our results identify the first disease-specific mechanism for deregulation of FHL2 nuclear localization during cancer progression. These results offer general import beyond prostate cancer, given that nuclear FHL2 is characteristic of other human cancers where oncogenic transcription factors that drive disease are activated like the AR in prostate cancer.

  20. The transcriptional coactivator PGC-1alpha is essential for maximal and efficient cardiac mitochondrial fatty acid oxidation and lipid homeostasis.

    PubMed

    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

    2008-07-01

    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-gamma coactivator (PGC)-1alpha is capable of activating postnatal cardiac myocyte mitochondrial biogenesis. Recently, we generated mice deficient in PGC-1alpha (PGC-1alpha(-/-) mice), which survive with modestly blunted postnatal cardiac growth. To determine if PGC-1alpha is essential for normal cardiac energy metabolic capacity, mitochondrial function experiments were performed on saponin-permeabilized myocardial fibers from PGC-1alpha(-/-) mice. These experiments demonstrated reduced maximal (state 3) palmitoyl-l-carnitine respiration and increased maximal (state 3) pyruvate respiration in PGC-1alpha(-/-) mice compared with PGC-1alpha(+/+) controls. ATP synthesis rates obtained during maximal (state 3) respiration in permeabilized myocardial fibers were reduced for PGC-1alpha(-/-) mice, whereas ATP produced per oxygen consumed (ATP/O), a measure of metabolic efficiency, was decreased by 58% for PGC-1alpha(-/-) fibers. Ex vivo isolated working heart experiments demonstrated that PGC-1alpha(-/-) mice exhibited lower cardiac power, reduced palmitate oxidation, and increased reliance on glucose oxidation, with the latter likely a compensatory response. (13)C NMR revealed that hearts from PGC-1alpha(-/-) mice exhibited a limited capacity to recruit triglyceride as a source for lipid oxidation during beta-adrenergic challenge. Consistent with reduced mitochondrial fatty acid oxidative enzyme gene expression, the total triglyceride content was greater in hearts of PGC-1alpha(-/-) mice relative to PGC-1alpha(+/+) following a fast. Overall, these results demonstrate that PGC-1alpha is essential for the maintenance of maximal, efficient cardiac

  1. 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.

  2. 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

  3. 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

  4. 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.

  5. Risk analysis of prospects vs. plays: The play`s the thing!

    SciTech Connect

    Rose, P.R.

    1996-09-01

    The most difficult and crucial decision in petroleum exploration is not which prospect to drill, but rather, which new play to enter. Such a decision, whether ultimately profitable or not, commits the Organization to years of involvement, expenditures of $millions, and hundreds of man-years of effort. Even though uncertainties and risks are high, organizations commonly make the new-play decision in a disjointed, non-analytic, even superficial way. The economic consequences of a bad play choice can be disastrous. Using established principles of prospect risk analysis, modern petroleum exploration organizations routinely assign economic value to individual prospects, but they actually operate via exploration programs in plays and trends. Accordingly, the prospect is the economic unit of exploration, whereas the play is the operational unit. Plays can be successfully analyzed as full-cycle economic risk ventures, however, using many principles of prospect risk analysis. Economic measures such as Expected Present Value, DCFROR, etc. apply equally to plays or prospects. The predicted field-size distribution of the play is analogous to the forecast prospect reserves distribution. Economic truncation applies to both. Variance of play reserves is usually much greater than for prospect reserves. Geologic chance factors such as P{sub reservoir}, P{sub generation}, etc., must be distinguished as independent or shared among prospects in the play, so they should be defined so as to apply as well to the play as to its constituent prospects. They are analogous to multiple objectives on a prospect, and are handled different in reforming the risk analysis.

  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. Play for Children in Hospital

    ERIC Educational Resources Information Center

    Hardgrove, Carol; And Others

    1976-01-01

    Contains six short articles on therapeutic play. Each article is an edited version of a paper delivered at the XIV World Congress of Pediatrics in Buenos Aires on the subject of children in the hospital. (JMB)

  8. [Sports participation and fair play].

    PubMed

    Cecchini Estrada, José A; González-Mesa, Carmen González; Méndez, Javier Montero

    2007-02-01

    This study examined whether the participation in intermediate contact sports affects the opinions about the behaviors and attitudes of fair play in the sports context and whether these effects are influenced by ego orientation. The participants were high level sportsmen from university and professional basketball and football players (N = 131). They filled in questionnaires to assess their participation in sports, their goal orientations, and their fair play attitudes and behaviors. The analyses of the structural equation model indicated that participation in intermediate contact sports predicted ego orientation; these analyses consecutively predicted low levels of fair play. The direct effects of sports participation in fair play decreased significantly in the presence of ego orientation, indicating that the last construct partially mediates the relation between the first two variables. These discoveries help us to better understand the processes that operate in contact sports. Finally, their implications for eliminating unsportsmanlike behaviors are discussed.

  9. Digital Play: A New Classification

    ERIC Educational Resources Information Center

    Marsh, Jackie; Plowman, Lydia; Yamada-Rice, Dylan; Bishop, Julia; Scott, Fiona

    2016-01-01

    This paper draws on an ESRC-funded study of play and creativity in preschool-aged children's use of apps in the UK. The main objectives of the study were to collect information about access to and use of apps in the home, establish the most popular apps and identify the features of those apps that are successful in promoting play and creativity. A…

  10. Follicular development and expression of nuclear respiratory factor-1 and peroxisome proliferator-activated receptor γ coactivator-1 alpha in ovaries of fetal and neonatal doelings.

    PubMed

    Zhou, Z; Wan, Y; Zhang, Y; Wang, Z; Jia, R; Fan, Y; Nie, H; Ying, S; Huang, P; Wang, F

    2012-11-01

    In livestock, the ovarian reserve of follicles is established during the fetal stage. However, at least two-thirds of the oocytes present in the reserve die because of apoptosis before birth. Notably, mitochondria have been reported to play a crucial role in the fate (life/death) of oocytes. In this study, mitochondrial regulators nuclear respiratory factor-1 (NRF-1) and PPAR γ coactivator-1 alpha (PGC-1α) were examined during this period of follicle development to investigate their effects on follicular development and apoptosis. Fetal and neonatal Capra haimen were used, ranging in age from 60 d postcoitum (dpc) to 30 d postpartum (dpp). Our data demonstrated that egg nests were the earliest recognizable gamete cells in ovaries of fetal and neonatal doelings. Proportions of egg nests decreased from 92.68 to 25.08% whereas single follicles increased from 7.32 to 74.92% between 60 and 120 dpc. Subsequently, between 90 and 120 dpc, the proportion of primordial follicles increased from 9.98 to 61.56% (P < 0.01). However, it did not change between 1 and 30 dpp (P = 0.12). The proportion of primary follicles increased from 1.23 to 37.93% between 90 dpc to 1 dpp (P = 0.01) but did not change between 1 and 30 dpp (P = 0.11). Meanwhile, proportions of secondary and tertiary follicles increased in an age-dependent manner. In addition, results of this study suggested that NRF-1 and PGC-1α proteins are mainly localized in germ cells of egg nests, cytoplasm of oocytes, and granulosa cells of follicles ranging from primordial to tertiary follicles. The transcript abundance of NRF-1 mRNA was up-regulated in 60-dpc-old ovaries compared with 1-dpp-old ovaries (P < 0.05), but the PGC-1α mRNA expression pattern did not change (P = 0.05). Nevertheless, the number of terminal deoxynucleotidyltransferase UTP nick-end labeling (TUNEL) positive cells and caspase-3 activity in 60-dpc-old ovaries was less than those in 1-dpp-old ovaries (P < 0.01, P = 0.01). In conclusion, our results

  11. Playing in the Gutters: Enhancing Children's Cognitive and Social Play.

    ERIC Educational Resources Information Center

    Dinwiddie, Sue A.

    1993-01-01

    Adding plastic gutters to the nursery school's sand area began as a science curriculum enhancement and evolved into a whole curriculum that stimulated cognitive exploration, cooperative dramatic play, language enhancement, and general fun. The children manipulated the gutters and materials such as sand, water, buckets, and tennis balls in a…

  12. 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…

  13. 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…

  14. Acetylation and succinylation contribute to maturational alterations in energy metabolism in the newborn heart.

    PubMed

    Fukushima, Arata; Alrob, Osama Abo; Zhang, Liyan; Wagg, Cory S; Altamimi, Tariq; Rawat, Sonia; Rebeyka, Ivan M; Kantor, Paul F; Lopaschuk, Gary D

    2016-08-01

    Dramatic maturational changes in cardiac energy metabolism occur in the newborn period, with a shift from glycolysis to fatty acid oxidation. Acetylation and succinylation of lysyl residues are novel posttranslational modifications involved in the control of cardiac energy metabolism. We investigated the impact of changes in protein acetylation/succinylation on the maturational changes in energy metabolism of 1-, 7-, and 21-day-old rabbit hearts. Cardiac fatty acid β-oxidation rates increased in 21-day vs. 1- and 7-day-old hearts, whereas glycolysis and glucose oxidation rates decreased in 21-day-old hearts. The fatty acid oxidation enzymes, long-chain acyl-CoA dehydrogenase (LCAD) and β-hydroxyacyl-CoA dehydrogenase (β-HAD), were hyperacetylated with maturation, positively correlated with their activities and fatty acid β-oxidation rates. This alteration was associated with increased expression of the mitochondrial acetyltransferase, general control of amino acid synthesis 5 like 1 (GCN5L1), since silencing GCN5L1 mRNA in H9c2 cells significantly reduced acetylation and activity of LCAD and β-HAD. An increase in mitochondrial ATP production rates with maturation was associated with the decreased acetylation of peroxisome proliferator-activated receptor-γ coactivator-1α, a transcriptional regulator for mitochondrial biogenesis. In addition, hypoxia-inducible factor-1α, hexokinase, and phosphoglycerate mutase expression declined postbirth, whereas acetylation of these glycolytic enzymes increased. Phosphorylation rather than acetylation of pyruvate dehydrogenase (PDH) increased in 21-day-old hearts, accounting for the low glucose oxidation postbirth. A maturational increase was also observed in succinylation of PDH and LCAD. Collectively, our data are the first suggesting that acetylation and succinylation of the key metabolic enzymes in newborn hearts play a crucial role in cardiac energy metabolism with maturation. PMID:27261364

  15. "Cum play" among gay men.

    PubMed

    Prestage, Garrett; Hurley, Michael; Brown, Graham

    2013-10-01

    The exchange of semen, often referred to as "cum play," has featured in gay literature and may be a unique aspect of many gay men's sexual behavior. We investigated the prevalence of "cum play" and its context among 1153 HIV-negative and 147 HIV-positive Australian gay men in an online survey. Receptive cum play (partner ejaculating or rubbing his semen over participant's anus, or participant using partner's semen as lubricant) was reported by one in six HIV-negative and one quarter of HIV-positive men on the same occasion of protected anal intercourse with a casual partner (PAIC). HIV-negative men who engaged in receptive cum play during PAIC often believed that their partner was HIV seroconcordant and tended to trust that partner. They were also generally more optimistic about the likelihood of HIV transmission, and they often only used condoms at their partners' instigation. Cum play was not uncommon and highlights the narrowness (or danger) of focusing on condom use without considering the implications of broader sexual practices and their meaning for sexual health promotion. "Safe sex" for some gay and bisexual men does not necessarily mean consistent commitment to condom use or to avoiding semen exchange. Many feel confident in their knowledge of their partner's HIV serostatus and only use condoms with these partners at their partner's request. Their commitment to safe sex may not necessarily be compromised by their practice of cum play, but the extent to which this could represent a risk for HIV transmission depends on the reliability of their assessment of their partners' HIV serostatus.

  16. 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

  17. 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.

  18. Identification of a putative Solanum tuberosum transcriptional coactivator up-regulated in potato tubers by Fusarium solani f. sp. eumartii infection and wounding.

    PubMed

    Godoy, Andrea V.; Zanetti, María Eugenia; San Segundo, Blanca; Casalongué, Claudia A.

    2001-06-01

    Coadaptors or coactivators are a new class of transcription factors capable of interconnecting a regulator DNA-binding protein with a component of the basal transcription machinery allowing transcriptional activation to proceed. We report the identification of a novel Solanum tuberosum ssp. tuberosum putative transcription coactivator, named StMBF1 (Solanum tuberosum multiprotein bridging factor 1). The StMBF1 cDNA was isolated from a Fusarium solani f. sp. eumartii-infected potato tuber cDNA library, using a differential screening approach. StMBF1 is up-regulated during fungal attack as well as on wounding. A Fusarium elicitor source and ethylene precursor and salicylic acid also regulate StMBF1 expression. The precise role of StMBF1 during the plant response against environmental stresses remains to be elucidated.

  19. Application of Circular Dichroism Spectroscopy to the Analysis of the Interaction Between the Estrogen Receptor Alpha and Coactivators: The Case of Calmodulin.

    PubMed

    Miclet, Emeric; Bourgoin-Voillard, Sandrine; Byrne, Cillian; Jacquot, Yves

    2016-01-01

    The estrogen receptor α ligand-binding domain (ERα-LBD) binds the natural hormone 17β-estradiol (E2) to induce transcription and cell proliferation. This process occurs with the contribution of protein and peptide partners (also called coactivators) that can modulate the structure of ERα, and therefore its specificity of action. As with most transcription factors, ERα exhibits a high content of α helix, making it difficult to routinely run spectroscopic studies capable of deciphering the secondary structure of the different partners under binding conditions. Ca(2+)-calmodulin, a protein also highly structured in α-helix, is a key coactivator for ERα activity. Here, we show how circular dichroism can be used to study the interaction of ERα with Ca(2+)-calmodulin. Our approach allows the determination not only of the conformational changes induced upon complex formation but also the dissociation constant (K d) of this interaction. PMID:26585140

  20. Recommendations for Child Play Areas.

    ERIC Educational Resources Information Center

    Cohen, Uriel; Hill, Ann B.; Lane, Carol G.; McGinty, Tim; Moore, Gary T.

    This interim criteria document provides descriptive information and planning, evaluation, and design guidelines for children's play areas located on military bases. The recommendations are presented in two major sections: planning & architecture design. Subcategories within the planning, criteria, and recommendations section address program master…