Bivalent complexes of PRC1 with orthologs of BRD4 and MOZ/MORF target developmental genes in Drosophila
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PROVIDER: PRJNA408128 | ENA |
REPOSITORIES: ENA
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Project description:Regulatory decisions in Drosophila require Polycomb group (PcG) proteins to maintain the silent state and Trithorax group (TrxG) proteins to oppose silencing. Since PcG and TrxG are ubiquitous and lack apparent sequence specificity, a long-standing model is that targeting occurs via protein interactions; for instance, between repressors and PcG proteins. Instead, we found that Pc-repressive complex 1 (PRC1) purifies with coactivators Fs(1)h [female sterile (1) homeotic] and Enok/Br140 during embryogenesis. Fs(1)h is a TrxG member and the ortholog of BRD4, a bromodomain protein that binds to acetylated histones and is a key transcriptional coactivator in mammals. Enok and Br140, another bromodomain protein, are orthologous to subunits of a mammalian MOZ/MORF acetyltransferase complex. Here we confirm PRC1-Br140 and PRC1-Fs(1)h interactions and identify their genomic binding sites. PRC1-Br140 bind developmental genes in fly embryos, with analogous co-occupancy of PRC1 and a Br140 ortholog, BRD1, at bivalent loci in human embryonic stem (ES) cells. We propose that identification of PRC1-Br140 "bivalent complexes" in fly embryos supports and extends the bivalency model posited in mammalian cells, in which the coexistence of H3K4me3 and H3K27me3 at developmental promoters represents a poised transcriptional state. We further speculate that local competition between acetylation and deacetylation may play a critical role in the resolution of bivalent protein complexes during development.
2018-02-22 | GSE104059 | GEO
Project description:In this project, we provide strong proteomic evidence for PcG interaction with classic co-activators, BRD4 and MOZ/MORF, captured on chromatin during embryogenesis in Drosophila, leading to a model in which developmental regulatory elements are universally ‘poised’ early in development via occupancy of composite protein complexes of PcG silencing proteins and classical co-activators. These bivalent protein interactions may resolve into full activation or repression, depending on the cell type-specific expression, binding, and function of transcription factors.
2017-11-02 | PXD006079 | Pride
Project description: Not available
| S-EPMC5710143 | biostudies-literature
Project description:Monocytic leukemia Zinc finger protein (MOZ) is a MYST-type acetyltransferase involved in chromosomal translocation in acute myelogenous leukemia (AML) and myelodysplastic syndrome. MOZ is established as essential for hematopoiesis; however, the role of MOZ in AML has not been addressed. We propose that MOZ is critical for AML development induced by MOZ-TIF2 fusions. Moz-deficient hematopoietic stem/progenitor cells (HSPCs) expressing MOZ-TIF2 could form colonies in vitro but could not induce AML in mice. By contrast, Moz was dispensable for colony formation by HOXA9-transduced cells and AML development caused by HOXA9 and MEIS1, suggesting a specific requirement for MOZ in AML induced by MOZ/MLL-fusions. Expression of the of Meis1, but not Hoxa9, was reduced in Moz-deficient MOZ-TIF2 AML cells. AML development induced by MOZ-TIF2 was rescued by introducing Meis1 into Moz-deficient cells carrying MOZ-TIF2. Meis1 deletion impaired MOZ-TIF2-mediated AML development. Active histone modifications were also severely reduced at the Meis1 locus in Moz-deficient MOZ-TIF2 AML cells. These results suggest that endogenous MOZ is critical for MOZ-fusion-induced AML development and maintains active chromatin signatures at target gene loci.
2022-07-24 | GSE208741 | GEO
Project description:In embryonic stem (ES) cells, bivalent chromatin domains with overlapping repressive (H3 lysine 27 tri-methylation) and activating (H3 lysine 4 tri-methylation) histone modifications mark the promoters of more than 2000 genes. To gain insight into the structure and function of bivalent domains, we mapped key histone modifications and subunits of Polycomb repressive complexes 1 and 2 (PRC1 and PRC2) genomewide in human and mouse ES cells by chromatin immunoprecipitation followed by ultra high-throughput sequencing. We find that bivalent domains can be segregated into two classes: the first occupied by both PRC2 and PRC1 (PRC1-positive) and the second specifically bound by PRC2 (PRC2-only). PRC1-positive bivalent domains appear functionally distinct as they more efficiently retain lysine 27 tri-methylation upon differentiation, show stringent conservation of chromatin state, and associate with an overwhelming number of developmental regulator gene promoters. We also used computational genomics to search for sequence determinants of Polycomb binding. This analysis revealed that the genomewide locations of PRC2 and PRC1 can be largely predicted from the locations, sizes and underlying motif contents of CpG islands. We propose that large CpG islands depleted of activating motifs confer epigenetic memory by recruiting the full repertoire of Polycomb complexes. Keywords: cell type comparison Suz12, Ezh2, Ring1b ChIP-Seq in singlicate from mouse embryonic stem (mES) cells. H3K4me3, H3K27me3, H3K36me3, Ezh2 and Ring1b ChIP-Seq in singlicate from human embyonic stem cells (hES; H9).
2008-11-01 | E-GEOD-13084 | biostudies-arrayexpress
Project description:The heterogeneous nature of mammalian PRC1 complexes has hindered our understanding of their biological functions. Here, we present a comprehensive proteomic and genomic analysis that uncovered six major groups of PRC1 complexes each containing a distinct PCGF subunit, a RING1A/B ubiquitin ligase, and a unique set of associated polypeptides. These PRC1 complexes differ in their genomic localization and only a small subset co-localize with H3K27me3. Further biochemical dissection revealed that the six PCGFM-bM-^@M-^SRING1A/B combinations form multiple complexes through association with RYBP or its homolog YAF2, which prevents the incorporation of other canonical PRC1 subunits such as CBX, PHC and SCM. Although both RYBP/YAF2- and CBX/PHC/SCM-containing complexes compact chromatin, only RYBP stimulates the activity of RING1B toward H2AK119ub1, suggesting a central role in PRC1 function. Knockdown of RYBP in ES cells compromised their ability to form embryoid bodies, likely because of defects in cell proliferation and maintenance of H2AK119ub1 level. ChIP-seq experiments of different PRC1 components were performed either on HA-tagged transgenic stable 293T-REx lines or on endogenous subunits using specific antibodies.
2012-02-09 | E-GEOD-34774 | biostudies-arrayexpress
Project description:In embryonic stem (ES) cells, bivalent chromatin domains with overlapping repressive (H3 lysine 27 tri-methylation) and activating (H3 lysine 4 tri-methylation) histone modifications mark the promoters of more than 2000 genes. To gain insight into the structure and function of bivalent domains, we mapped key histone modifications and subunits of Polycomb repressive complexes 1 and 2 (PRC1 and PRC2) genomewide in human and mouse ES cells by chromatin immunoprecipitation followed by ultra high-throughput sequencing. We find that bivalent domains can be segregated into two classes: the first occupied by both PRC2 and PRC1 (PRC1-positive) and the second specifically bound by PRC2 (PRC2-only). PRC1-positive bivalent domains appear functionally distinct as they more efficiently retain lysine 27 tri-methylation upon differentiation, show stringent conservation of chromatin state, and associate with an overwhelming number of developmental regulator gene promoters. We also used computational genomics to search for sequence determinants of Polycomb binding. This analysis revealed that the genomewide locations of PRC2 and PRC1 can be largely predicted from the locations, sizes and underlying motif contents of CpG islands. We propose that large CpG islands depleted of activating motifs confer epigenetic memory by recruiting the full repertoire of Polycomb complexes. Keywords: cell type comparison
2008-11-01 | GSE13084 | GEO
Project description:The heterogeneous nature of mammalian PRC1 complexes has hindered our understanding of their biological functions. Here, we present a comprehensive proteomic and genomic analysis that uncovered six major groups of PRC1 complexes each containing a distinct PCGF subunit, a RING1A/B ubiquitin ligase, and a unique set of associated polypeptides. These PRC1 complexes differ in their genomic localization and only a small subset co-localize with H3K27me3. Further biochemical dissection revealed that the six PCGF–RING1A/B combinations form multiple complexes through association with RYBP or its homolog YAF2, which prevents the incorporation of other canonical PRC1 subunits such as CBX, PHC and SCM. Although both RYBP/YAF2- and CBX/PHC/SCM-containing complexes compact chromatin, only RYBP stimulates the activity of RING1B toward H2AK119ub1, suggesting a central role in PRC1 function. Knockdown of RYBP in ES cells compromised their ability to form embryoid bodies, likely because of defects in cell proliferation and maintenance of H2AK119ub1 level.
2012-02-09 | GSE34774 | GEO
Project description:Carboxy-terminally tagged MOZ (Flag-V5-BIO tagged) was detected by ChIP-seq using anti-V5 antibody (Sigma, A7345) to precipitate chromatin associated with MOZ
2019-07-23 | GSE134607 | GEO
Project description:Hepatocellular carcinoma (HCC) is the fifth leading cause of cancer-related death worldwide because of late stage detection when curative therapy is not available. The bromodomain and extraterminal (BET) protein BRD4 activates gene expression by interacting with histone H3K27-acetylated (H3K27Ac) chromatin. AZD5153 is an orally bioavailable, potent, bivalent BRD4 inhibitor, currently undergoing clinical trials in lymphoma and ovarian cancer patients. Here, we studied therapeutic potential of AZD5153 against HCC and elucidated the underlying mechanism. In conclusion, our results in preclinical models indicate that the combined effect of AZD5153 could be a novel targeted therapy for HCC and provides rationale for clinical trials of an AZD5153-FK866 combination as an effective and attractive strategy to treat this deadly disease.
2022-01-13 | GSE172186 | GEO