Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

A Non-canonical BCOR-PRC1.1 Complex Represses Differentiation Programs in Human ESCs

ABSTRACT: Polycomb group proteins regulate self-renewal and differentiation in many stem cell systems. When assembled into two canonical complexes, PRC1 and PRC2, they sequentially deposit H3K27me3 and H2AK119ub histone marks and establish repressive chromatin, referred to as Polycomb domains. Non-canonical PRC1 complexes retain RING1/ RNF2 E3-ubiquitin ligases but have unique sets of accessory subunits. How these non-canonical complexes recognize and regulate their gene targets remains poorly understood. Here, we show that the BCL6 co-repressor (BCOR), a member of the PRC1.1 complex, is critical for maintaining primed pluripotency in human embryonic stem cells (ESCs). BCOR depletion leads to the erosion of Polycomb domains at key developmental loci and the initiation of differentiation along endoderm and mesoderm lineages. The C terminus of BCOR regulates the assembly and targeting of the PRC1.1 complex, while the N terminus contributes to BCOR-PRC1.1 repressor function. Our findings advance understanding of Polycomb targeting and repression in ESCs and could apply broadly across developmental systems.

ORGANISM(S): Homo sapiens

PROVIDER: GSE104690 | GEO | 2018/01/11

SECONDARY ACCESSION(S): PRJNA413520

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

BCOR and BCORL1 Mutations Drive Epigenetic Reprogramming and Oncogenic Signaling by Unlinking PRC1.1 from Target Genes

Project description:Polycomb repressive epigenetic complexes are recurrently dysregulated in cancer. Unlike polycomb repressive complex 2 (PRC2), the role of PRC1 in oncogenesis and therapy resistance is not well defined. Here, we demonstrate that highly recurrent mutations of the PRC1 subunits BCOR and BCORL1 in leukemia disrupt assembly of a non-canonical PRC1.1 complex, thereby selectively unlinking the RING-PCGF enzymatic core from the chromatin targeting auxiliary subcomplex. As a result, BCOR-mutated PRC1.1 is localized to chromatin but lacks repressive activity, leading to epigenetic reprogramming and transcriptional activation at target loci. We define a set of functional targets that drive aberrant oncogenic signaling programs in PRC1.1 mutated cells and primary patient samples. Activation of these PRC1.1 targets in BCOR-mutated cells confers acquired resistance to treatment while sensitizing to targeted kinase inhibition. Our study thus reveals a novel epigenetic mechanism that explains PRC1.1 tumor suppressive activity and identifies a therapeutic strategy in PRC1.1 mutated cancer.

2022-02-28 | GSE167869 | GEO

EZH2 and BCL6 cooperate to assemble CBX8-BCOR Polycomb complex to repress bivalent promoters, mediate germinal center formation and promote lymphomagenesis [ChIP-seq]

Project description:The EZH2 histone methyltransferase mediates the humoral immune response and drives lymphomagenesis through de novo formation of bivalent chromatin domains at critical germinal center (GC) B cell promoters. Herein we show that the actions EZH2 in driving GC formation and lymphoma precursor lesions are dependent on the presence of the BCL6 transcriptional repressor, both of which are in turn dependent on the presence of non-canonical PRC1-BCOR complex. BCL6-BCOR complexes assemble preferentially at bivalent promoters in an H3K27me3-dependent manner. We observe specific induction of the CBX8 chromodomain protein in GC B cells. CBX8 binds to H3K27me3 at bivalent promoters and is required for stable association of BCOR complex and its histone modifications. CBX8 loss of function in B cells phenocopies loss of EZH2 and H3K27me3. Moreover, oncogenic BCL6 and EZH2 cooperate to accelerate diffuse large B cell lymphoma (DLBCL) development and combinatorial targeting of these repressors results in enhanced anti-lymphoma activity in vitro, in vivo and in primary human DLBCLs. KDM2B ChIP-sequencing of OCI-Ly1 cells

2016-07-20 | E-GEOD-81623 | biostudies-arrayexpress

H3K27me3 is not required for recruitment of Polycomb repressor complex 1 to target loci in mouse embryonic stem cells

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

Kdm2b regulates somatic reprogramming through variant PRC1 complex dependent function [RNA-seq]

Project description:Polycomb repressive complex 1 (PRC1) plays essential roles in cell fate determination. Recent studies have found that the composition of mammalian PRC1 is particularly varied and complicated, whereas the function of such variant PRC1 complexes on cell fate determination remains unknown. Here we show that Kdm2b, which recruits a variant PRC1 complex (PRC1.1) to CpG islands (CGIs), elevates Oct4 induced somatic reprogramming. Interaction with PRC1 is critical for Kdm2b’s promotion on the process of induced pluripotency. Furthermore, we find that bone morphogenetic proteins (BMPs) repress Oct4/Kdm2b induced somatic reprogramming selectively. Mechanistically, BMP-Smad pathway attenuates PRC1.1 occupation and H2AK119 ubiquitination on development genes, resulting in the release of meso-endoderm factors such as Sox17 and suppression of somatic reprogramming. These observations reveal that PRC1.1 participates in the establishment of pluripotency as well as cellular differentiation and identify BMP signal as a modulator of PRC1.1 function.

2017-11-19 | GSE93974 | GEO

Kdm2b regulates somatic reprogramming through variant PRC1 complex dependent function [ChIP-seq, MeDIP-seq]

2017-11-19 | GSE93972 | GEO

EZH2 and BCL6 cooperate to assemble CBX8-BCOR Polycomb complex to repress bivalent promoters, mediate germinal center formation and promote lymphomagenesis [ChIP-seq]

2016-07-20 | GSE81623 | GEO

A Non-canonical BCOR-PRC1.1 Complex Represses Differentiation Programs in Human ESCs

Project description:A Non-canonical BCOR-PRC1.1 Complex Represses Differentiation Programs in Human ESCs

| PRJNA413520 | ENA

The Polycomb group protein CBX6 is an essential regulator of embryonic stem cell identity

Project description:Polycomb group proteins are transcriptional repressors that control cell identity and development. In mammals, at least five different CBX proteins are believed to associate with the core Polycomb repressive complex 1 (PRC1). CBX6 and CBX7 are the most highly expressed CBX proteins in embryonic stem cells (ESCs), yet little is known about the function of CBX6 in these cells. Here we show that CBX6 is an essential regulator of ESC identity, since ablation of CBX6 function destabilizes the pluripotency network and triggers differentiation. At the molecular level, CBX6 is linked to the canonical PRC1 (cPRC1) complex; however, contrary to expectations, our results indicate that CBX6 also has a non-canonical PRC1 function. Taken together, our findings reveal that CBX6 is an essential component for ESC biology and contributes to the structural and functional complexity of the PRC1 complex.

2017-09-25 | PXD007577 | Pride

Multi-omics characterization of the USP7 regulatory circuitry reveals control of H2AK119ub1 dosage uncoupled from H3K27me3 .

Project description:Ubiquitin-specific protease 7 (USP7) has been implicated in multiple cellular and developmental pathways. However, its molecular network remains poorly defined. We combined quantitative proteomics, transcriptomics and epigenomics to define the core USP7 regulome. We found that USP7 forms a regulatory hub, linking processes involved in the packaging, maintenance and expression of the genome. Further analysis revealed that USP7 regulates non-canonical Polycomb repressive complexes 1 (ncPRC1s) but affects neither canonical PRC1s nor PRC2s. By stabilizing key subunits of PRC1.6 and to a lesser extend PRC1.1, USP7 acts as a rheostat that modulates the global level of H2AK119ub11. Unexpectedly, changes in the genomic deposition of H2AK119ub11 are uncoupled from H3K27me3, challenging prevalent models for Polycomb repression. Indeed, a complete loss of PRC1 and H2AK119ub1 has only a highly restricted effect on H3K27me3. Besides defining the organizational principles of the USP7 regulome, our results reveal selective control of H2AK119ub1 dosage that is disconnected from H3K27me3.

2023-03-11 | PXD030707 | Pride

H3K27me3 is not required for recruitment of Polycomb repressor complex 1 to target loci in mouse embryonic stem cells

2011-11-30 | GSE23716 | GEO