Drosophila melanogaster
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA94489 | ENA |
REPOSITORIES: ENA
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Project description:Our proteomics anaylsis in Drosophila embryos revealed alternative forms of PRC2 and several distinct variant PRC1 types which are similar to polycomb complexes in mammals
2022-10-15 | PXD033615 | Pride
Project description:Polycomb group proteins form two main complexes, PRC2 and PRC1, which generally coregulate their target genes. Here, we show that PRC1 components act as neoplastic tumor suppressors independently of PRC2 function. By mapping the distribution of PRC1 components and the histone H3K27me3 mark, we identify genes that acquire PRC1 and H3K27me3 in larvae, and a much larger set of genes bound by PRC1 in the absence of H3K27me3 in larval tissues. These genes massively outnumber canonical targets and they are preeminently involved in the regulation of cell proliferation, signaling and polarity. Mutation in PRC1 components specifically deregulates this set of genes, whereas canonical targets are derepressed in both PRC1 and PRC2 mutants. In human ES cells, PRC1 components colocalize with H3K27me3 like in Drosophila embryos, whereas they are selectively recruited to a large set of proliferation and signaling-associated genes in differentiated cell types, showing that the redeployment of PRC1 components during development is evolutionarily conserved. Comparative study of Polycomb group proteins and histon marks during development with ChIP-Seq and RNA-Seq data in eye discs and wing discs (L3 stage) in Drosophila
2016-07-18 | E-GEOD-74080 | biostudies-arrayexpress
Project description:Polycomb repressive complexes 1 and 2 (PRC1 and PRC2) are highly conserved epigenetic factors that collaborate at multiple levels to maintain their target genes in a repressed state. However, recent reports suggest that PRC1 binds a subset of active promoters and enhancers devoid of the PRC2-mediated H3K27me3 repressive mark in both Drosophila and mammals. Here, we characterize the 3D epigenome of Drosophila Eye-antennal imaginal discs (EDs) and identify a large set of PRC1-bound promoters and enhancers that show preferential interactions in 3D. These PRC1-centered contacts are generally not pre-formed in embryos and coincide with increased PRC1 binding at the larval stage, a concomitant increase in expression during development and mis-regulation in PRC1 mutants. A detailed analysis of the dachshund locus indicates that PRC1-anchored chromatin loops are not only repressive structures, but might also be required for gene activation. Finally, a meta-analysis of RING1B binding profiles and 3D contacts during mouse neural differentiation suggests that this function might be conserved in mammals. These data suggest that, in addition to its known function in gene silencing, PRC1 binding to enhancers and promoters favors stage-specific 3D contacts to facilitate transcription of key developmental genes.
2020-01-12 | GSE126985 | GEO
Project description:Polycomb group (PcG) mutants were first identified in Drosophila based on their failure to maintain proper Hox gene repression during development. The proteins encoded by the corresponding fly genes mainly assemble into one of two discrete Polycomb Repressive Complexes: PRC1 or PRC2. However, biochemical analyses in mammals have revealed alternative forms of PRC2, and multiple distinct types of non-canonical or variant PRC1. Through a series of proteomic analyses, we identify analogous PRC2 and variant PRC1 complexes in Drosophila, as well as a broader repertoire of interactions implicated in early development. Our data provide strong support for the ancient diversity of PcG complexes, and a framework for future analysis in a longstanding and versatile genetic system.
2022-04-29 | GSE201842 | GEO
Project description:The chromatin modifying activities inherent to polycomb repressive complexes PRC1 and PRC2 play an essential role in gene regulation, cellular differentiation, and development. However, the mechanisms by which these complexes recognize their target sites and function together to form repressive chromatin domains remain poorly understood. Recruitment of PRC1 to target sites has been proposed to occur through a hierarchical process, dependent on the prior nucleation of PRC2 and placement of H3K27me3. Here, using a de novo targeting assay in mouse embryonic stem cells we unexpectedly discover that PRC1-dependent H2AK119ub1 leads to the recruitment of PRC2 and H3K27me3 to effectively initiate a polycomb domain. Genetic ablation of catalytic subunit of the PRC1 complex (RINGA/B) and ChIP-seq analysis of PRC1 and PRC2 components confirmed genome-wide decreases in PRC2 occupancy and H3K27me3 levels at PRC target sites. This activity is restricted to variant PRC1 complexes and genetic ablation experiments reveal that targeting of the variant PCGF1/PRC1 complex by KDM2B to CpG islands is required for polycomb domain formation and normal development. Together these observations provide a surprising new PRC1-dependent logic for PRC2 occupancy and polycomb domain formation. RING1A-/-;RING1Bfl/fl ES cells were treated with 800M-BM-5M tamoxifen for 48hours and compared to untreated control cells by ChIP-seq for RING1B, SUZ12, EZH2 and H3K27me3.
2014-05-27 | E-GEOD-55697 | biostudies-arrayexpress
Project description:Polycomb Group (PcG) proteins regulate gene expression through changes to chromatin structure and are essential for development. PcG proteins function together with the Trithorax Group (TrxG) proteins, which affect diverse steps in transcription activation. The PcG and TrxG are genetically and functionally antagonistic, and current understanding suggests a balance of their activities can maintain a wide range of transcription states. PcG and TrxG proteins assemble into a series of complexes. How these complexes work together, how PcG complexes are recruited to target genes, and whether other proteins are involved in their regulation of gene expression remain open questions. We carried out tandem affinity purification followed by mass spectrometry (TAP-MS) on two core components of Drosophila Polycomb Repressive Complex 1 (PRC1). Our data reveal a network of interactions among PcG complexes, and extensive co-purification of TrxG complexes with PRC1. We co-purified >50 transcription factors with PRC1 that were not previously linked to the PcG. Finally, we identify novel co-purifying complexes, including HP1c and PCNA handling complexes. Our resource of candidate PRC1 interacting proteins generate new hypotheses for PRC1 function.
2023-04-20 | MSV000091759 | MassIVE
Project description:While the core members of the Polycomb family of proteins (PRC2, PRC1, PR-DUB) are well-characterized, little is known about the specific composition of and protein-protein interactions within these complexes in different cell types. We performed quantitative interaction proteomics and cross-linking mass spectrometry on core Polycomb complex members to identify novel interactors, the relative abundance (stoichiometry) of subunits, and the architecture of these complexes in mouse embryonic stem cells (mESCs) and neural progenitor cells (NPCs). Differentiation to NPCs resulted in dramatic binding changes for several substoichiometric interactors of PRC2 and PRC1. ChIP-seq of core PRC2 and PRC1 subunits in mESCs and NPCs also identified dynamic changes in the genomic localization of these complexes. We observed a loss of PRC2 from most H3K27me3 sites during differentiation, whereas PRC1 is retained at these sites. Additionally, we found PRC1 at enhancers and promoters of active genes independent of PRC2 binding. Overexpression studies using NPC-specific PRC1 interactors demonstrated that the subunit switching observed during differentiation can change PRC1 target site binding. Altogether, these findings extend our understanding of Polycomb family composition, architecture, and genome-wide localization. ChIP-seq samples for Suz12, Ezh2, Ring1b, Pcgf2, and inputs from mouse embryonic stems cells (mES) and neural progenitor cells (NPC) as well as NPC histone H3K4me1 ChIP-seq.
2016-05-17 | E-GEOD-74330 | biostudies-arrayexpress
Project description:The established hierarchical model explaining co-occupancy of Polycomb repressor complexes 1 and 2 (PRC 1 and 2) at target loci proposes that the chromodomain of the polycomb protein, a core PRC1 subunit, recognises the H3K27me3 histone modification catalysed by PRC2. We used chromatin immunoprecipitation to analyse PRC1 occupancy at target loci in Eed-/- mouse embryonic stem cells (ESCs) that lack H3K27me3. Occupancy of the core PRC1 proteins Ring1B and Mel18 was strongly reduced, consistent with the hierarchical model. However, levels of H2A ubiquitylation (H2AK119u1), the histone modification catalysed by PRC1, were similar to wild-type cells, suggesting PRC1 recruitment is independent of H3K27me3. ChIP-sequencing analysis of Ring1B occupancy genome wide substantiated this conclusion, demonstrating significant Ring1B levels at polycomb target loci in Eed-/- ESCs. Thus PRC1 and PRC2 are recruited independently to sites that they co-occupy. We conclude that the primary function of H3K27me3 is to increase the residency of PRC1 at target loci and thereby to contribute to the stability of PRC1 mediated silencing. Examination of Ring1B binding in WT, Eed ko and Input of ESCs Examination of CBX7 in WT and Eed ko of ESCs
2011-11-30 | E-GEOD-23716 | biostudies-arrayexpress
Project description:Polycomb repressive complexes (PRCs) play key roles in developmental epigenetic regulation. Yet the mechanisms that target PRCs to specific loci in mammalian cells remain incompletely understood. In this study, we show that Bmi1, a core component of Polycomb Repressive Complex 1 (PRC1), binds directly to the Runx1/CBFbeta transcription factor complex. Genome-wide studies in megakaryocytic cells demonstrate considerable chromatin occupancy overlap between the PRC1 core component Ring1b and Runx1/CBFbeta and functional regulation of a significant fraction of commonly bound genes. Bmi1/Ring1b and Runx1/CBFbeta deficiency generate partial phenocopies of one another in vivo. We also show that Ring1b occupies key Runx1 binding sites in primary murine thymocytes and that this occurs via Polycomb Repressive Complex 2 (PRC2) independent mechanisms. Genetic depletion of Runx1 results in reduced Ring1b binding at these sites in vivo. These findings provide evidence for site-specific PRC1 chromatin recruitment by core binding transcription factors in mammalian cells. shRNA mediated knockdown of CBFb, Ring1b and control in biological triplicate
2012-02-10 | E-GEOD-33659 | biostudies-arrayexpress
Project description:The Polycomb repressive complexes PRC1 and PRC2 play a key role in chromosome silencing by Xist RNA. Previously we have shown that initation of Polycomb recruitment is mediated by the PCGF3/5-PRC1 complex, which catalyses chromosome-wide H2A ubiquitylation (H2AK119u1), signalling recruitment of other PRC1 complexes, and PRC2. However, the molecular basis for PCGF3/5-PRC1 recruitment by Xist RNA remains unknown. Here we define the Xist RNA Polycomb Interaction Domain (XR-PID), a 600 nt element encompassing the Xist B-repeat element. XR-PID is required for Polycomb recruitment by Xist RNA, Xist-mediated chromosome silencing. We identify the RNA-binding protein hnRNPK as the principal XR-PID binding factor required to recruit PCGF3/5-PRC1. Accordingly, synthetically tethering hnRNPK to Xist RNA lacking the B-repeat is sufficient for Xist-dependent Polycomb recruitment. Our findings resolve the molecular mechanism for Polycomb recruitment by Xist RNA, providing key insights into chromatin modification by non-coding RNA.
2017-12-08 | GSE99924 | GEO