SIN3A-regulated LIF-responsive genes in MCF7 cells
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE35696 | GEO | 2012/08/02
SECONDARY ACCESSION(S): PRJNA152031
REPOSITORIES: GEO
Similar Datasets
Project description:Tyrosine phosphorylation is a hallmark for activation of Signal Transducer and Activator of Transcription (STAT) proteins, but their transcriptional activity also depends on other secondary modifications. Type I interferons (IFNs) can activate both the ISGF3 (STAT1:STAT2:IRF9) complex and STAT3, but with cell-specific, selective triggering of only the ISGF3 transcriptional program. Following a genome-wide RNAi screen, we identified the Sin3a complex as an important mediator of this STAT3 transcriptional repression. Sin3a directly interacts with the DNA-binding domain of STAT3 and alters its acetylation status. SIN3A silencing enhances recruitment of STAT3 and enhanceosome components to the SOCS3 promoter, resulting in histone hyperacetylation and enhanced transcription. Conversely, Sin3a is required for ISGF3-dependent gene transcription and for an efficient IFN-mediated antiviral protection against Influenza A and hepatitis C viruses. The Sin3a complex therefore acts as a context-dependent STAT1/3 transcriptional switch. MCF7 cells were transfected with 50nM Renilla luciferase (control) or SIN3A-specific siRNA. 72h later, cells were cultured for 4h in absence of FCS and left non-stimulated or stimulated with LIF (10ng/ml, 1h). Total RNA was extracted. For each of the 4 conditions, 3 biological replicates were included. Nevertheless, one sample (SIN3A_siRNA_LIF1h_rep3) was discarded. In total 11 samples were analyzed.
2012-08-01 | E-GEOD-35696 | biostudies-arrayexpress
Project description:Virus infection induces the production of type I and type II interferons (IFN-I and IFN-II), cytokines that mediate the antiviral response. IFN-I (IFN-a and -b) induces the assembly of ISGF3 (interferon-stimulated gene factor 3), a multimeric transcriptional activation complex comprised of STAT1, STAT2 and IRF9. IFN-II (IFN-g) induces the homodimerization of STAT1 to form the GAF (gamma-activated factor) complex. ISGF3 and GAF bind specifically to distinct regulatory DNA sequences located upstream of IFN-I and II inducible genes, respectively, and activate the expression of distinct set of antiviral genes. The balance between the type I and type II IFN pathways plays a critical role in orchestrating the innate and adaptive immune systems. Here, we show that the phosphorylation of STAT1 by IKKε (IkB-related kinase epsilon) inhibits STAT1 homodimerization, and thus GAF formation, but does not disrupt ISGF3 formation. Therefore, virus and/or IFN-I activation of IKKε suppresses GAF-dependent transcription and promotes ISGF3-dependent transcription. In the absence of IKKε, GAF-dependent transcription is enhanced at the expense of ISGF3-mediated transcription, rendering cells less resistant to infection. We conclude that IKKε plays a critical role in regulating the balance between the IFN-I and IFN-II signaling pathways. ChIP-seq libraries were constructed with an antibody targeting STAT1 from bone marrow macrophages treated with interferon
2011-12-01 | E-GEOD-33913 | biostudies-arrayexpress
Project description:Sin3a is the central scaffold protein of the prototypical Hdac1/2 chromatin repressor complex, crucially required during early embryonic development for the growth of pluripotent cells of the inner cell mass. Here, we explore the endogenous composition of the Sin3a-Hdac complex in pluripotent embryonic stem (ES) and differentiated cells. To do this, we established an endogenous double immunoprecipitation strategy coupled with quantitative mass spectrometry (ENDIP-MS) allowing us to define the precise composition of the Sin3a complex in multiple cell types. We identify the Fam60a subunit as a key defining feature of a variant Sin3a complex present in ES cells, but not in differentiated cells. Fam60a co-occupies H3K4me3 positive promoters with Sin3a and is essential to maintain it on chromatin. Consistent with this, Fam60a depletion phenocopies the loss of Sin3a, leading to decreased proliferation, an extended G1-phase and the deregulation of genes associated with differentiation. Taken together, our data characterise Fam60a as an essential core subunit of a variant Sin3a complex in ES cells required to promote rapid proliferation and to prevent unscheduled differentiation.
2017-05-19 | PXD005464 | Pride
Project description:Virus infection induces the production of type I and type II interferons (IFN-I and IFN-II), cytokines that mediate the antiviral response. IFN-I (IFN-a and -b) induces the assembly of ISGF3 (interferon-stimulated gene factor 3), a multimeric transcriptional activation complex comprised of STAT1, STAT2 and IRF9. IFN-II (IFN-g) induces the homodimerization of STAT1 to form the GAF (gamma-activated factor) complex. ISGF3 and GAF bind specifically to distinct regulatory DNA sequences located upstream of IFN-I and II inducible genes, respectively, and activate the expression of distinct set of antiviral genes. The balance between the type I and type II IFN pathways plays a critical role in orchestrating the innate and adaptive immune systems. Here, we show that the phosphorylation of STAT1 by IKKε (IkB-related kinase epsilon) inhibits STAT1 homodimerization, and thus GAF formation, but does not disrupt ISGF3 formation. Therefore, virus and/or IFN-I activation of IKKε suppresses GAF-dependent transcription and promotes ISGF3-dependent transcription. In the absence of IKKε, GAF-dependent transcription is enhanced at the expense of ISGF3-mediated transcription, rendering cells less resistant to infection. We conclude that IKKε plays a critical role in regulating the balance between the IFN-I and IFN-II signaling pathways.
2011-12-01 | GSE33913 | GEO
Project description:The forkhead box (FOX) family of proteins is composed of more than 50 members that are phylogenetically classified into 19 subclasses (A to S). These transcription factors all share a homology in their DNA-binding domain, the forkhead domain, also known as winged helix due to its butterfly-like structural appearance.FOX proteins have been implicated in a broad spectrum of cellular processes including cell proliferation, differentiation, DNA repair, metabolism, and aging. However, the biological function of the mammalian forkhead transcription factors of the N class including FOXN3 remains to be investigated. The SIN3A complex is a large protein assembly consisting of over a dozen of proteins including SIN3A, HDAC1/2, RBBP4/7 and etc. This complex is recruited by multiple transcription repressors and impacts on multifaceted biological functions ranging from development, differentiation, and senescence to oncogenic transformation. Long noncoding RNAs (lncRNAs) are a class of noncoding RNAs that are over 200 nucleotides in length. In the past years, these molecules have emerged as important components of the epigenetic regulatory network to influence transcription as well as other nuclear activities, and their dysregulation underlies several pathologic states including cancer. One of the lncRNAs, NEAT1 (nuclear paraspeckle assembly transcript 1), is a highly abundant lncRNA initially described as a structural component of nuclear paraspeckles. Subsequent studies suggest that NEAT1 also influences transcription through either an indirect mechanism or a direct way. In this study, we investigated the function and the underlying mechanism of FOXN3 in breast cancer cells. We showed that FOXN3 is physically associated with the SIN3A complex and identified that NEAT1, which is induced by estrogen in breast cancer cells, is required for this interaction. We analyzed the genomic targets of the FOXN3/SIN3A/NEAT1 complex and demonstrated that estrogen receptor (ER) itself is regulated, through negative feedback, by the FOXN3/SIN3A/NEAT1 complex. We investigated the role of the FOXN3/SIN3A/NEAT1 complex in breast cancer metastasis and explored the clinicopathological significance of the ER-NEAT1-FOXN3/NEAT1/SIN3A-GATA3 axis in breast cancer.
2017-06-01 | GSE93780 | GEO
Project description:ChIP coupled with NGS identifies genome-wide binding sites of a ES cells specific Sin3a/Hdac complex. The aim of these experiments is to study the role of Fam60a in the Sin3a/Hdac complex. ChIP-Seq experiments reveal that Fam60a is required to maintain high levels of Sin3a binding on target genes in mESCs. Depletion of Fam60a causes a drop of Sin3a binding to target sites. Underlining the function of Fam60a in mES cells, ChIP-seq analysis of Sin3a and Fam60a in mouse fibroblasts reveal strikingly low global binding level of Sin3a to its target genes while Fam60a is absent at these sites.
2017-04-24 | GSE81081 | GEO
Project description:Despite the requirement of Sin3a for survival of early embryos and embryonic stem cells (ESCs), mechanistic action of Sin3a in the maintenance and establishment of pluripotency remains unexplored. Here we report the transcriptional regulatory roles of Sin3a in maintaining ESC pluripotency and in reprogramming somatic cells towards full pluripotency. Sin3a/HDAC complex members were enriched in an extended Nanog interactome and exhibited a predominant transcriptional co-activator role at a global level in ESCs. We also established a critical role for Sin3a in efficient reprogramming of somatic cells towards full pluripotency. Nanog and Sin3a co-localize at almost all of their genome-wide targets in pre-iPSCs, and both factors are required to directly induce a synergistic transcriptional program wherein pluripotency genes are activated and reprogramming barrier genes are repressed. Our results, for the first time, establish positive roles of the Sin3a/HDAC complex in the maintenance and establishment of pluripotency.
2017-02-21 | GSE90986 | GEO
Project description:Despite the requirement of Sin3a for survival of early embryos and embryonic stem cells (ESCs), mechanistic action of Sin3a in the maintenance and establishment of pluripotency remains unexplored. Here we report the transcriptional regulatory roles of Sin3a in maintaining ESC pluripotency and in reprogramming somatic cells towards full pluripotency. Sin3a/HDAC complex members were enriched in an extended Nanog interactome and exhibited a predominant transcriptional co-activator role at a global level in ESCs. We also established a critical role for Sin3a in efficient reprogramming of somatic cells towards full pluripotency. Nanog and Sin3a co-localize at almost all of their genome-wide targets in pre-iPSCs, and both factors are required to directly induce a synergistic transcriptional program wherein pluripotency genes are activated and reprogramming barrier genes are repressed. Our results, for the first time, establish positive roles of the Sin3a/HDAC complex in the maintenance and establishment of pluripotency.
2017-02-21 | GSE91021 | GEO
Project description:Cells adapt to environmental changes, including fluctuations in oxygen levels, through the induction of specific gene expression programs. To identify genes regulated by hypoxia at the transcriptional level, we pulse-labeled HUVEC cells with 4-thiouridine and sequenced nascent transcripts. Then, we searched genome-wide binding profiles from the ENCODE project for factors that correlated with changes in transcription and identified binding of several components of the Sin3A co-repressor complex, including SIN3A, SAP30 and HDAC1/2, proximal to genes repressed by hypoxia. SIN3A interference revealed that it participates in the downregulation of 75% of the hypoxia-repressed genes in endothelial cells. Unexpectedly, it also blunted the induction of 47% of the upregulated genes, suggesting a role for this corepressor in gene induction. In agreement, ChIP-seq experiments showed that SIN3A preferentially localizes to the promoter region of actively transcribed genes and that SIN3A signal was enriched in hypoxia-repressed genes, prior exposure to the stimulus. Importantly, SINA3 occupancy was not altered by hypoxia in spite of changes in H3K27ac signal. In summary, our results reveal a prominent role for SIN3A in the transcriptional response to hypoxia and suggest a model where modulation of the associated histone deacetylase activity, rather than its recruitment, determines the transcriptional output.
2017-09-15 | GSE89840 | GEO
Project description:Cells adapt to environmental changes, including fluctuations in oxygen levels, through the induction of specific gene expression programs. To identify genes regulated by hypoxia at the transcriptional level, we pulse-labeled HUVEC cells with 4-thiouridine and sequenced nascent transcripts. Then, we searched genome-wide binding profiles from the ENCODE project for factors that correlated with changes in transcription and identified binding of several components of the Sin3A co-repressor complex, including SIN3A, SAP30 and HDAC1/2, proximal to genes repressed by hypoxia. SIN3A interference revealed that it participates in the downregulation of 75% of the hypoxia-repressed genes in endothelial cells. Unexpectedly, it also blunted the induction of 47% of the upregulated genes, suggesting a role for this corepressor in gene induction. In agreement, ChIP-seq experiments showed that SIN3A preferentially localizes to the promoter region of actively transcribed genes and that SIN3A signal was enriched in hypoxia-repressed genes, prior exposure to the stimulus. Importantly, SINA3 occupancy was not altered by hypoxia in spite of changes in H3K27ac signal. In summary, our results reveal a prominent role for SIN3A in the transcriptional response to hypoxia and suggest a model where modulation of the associated histone deacetylase activity, rather than its recruitment, determines the transcriptional output.
2017-09-15 | GSE103245 | GEO