Similar Datasets
Project description:Polycomb group (PcG) proteins are critical chromatin regulators for cell fate control. The mono-ubiquitylation on histone H2AK119 (H2AK119ub1) is one of the well-recognized mechanisms for Polycomb repressive complex 1 (PRC1)-mediated transcription repression. Unexpectedly, the specific H2AK119 deubiquitylation complex composed by additional sex comb-like proteins and BAP1 has also been genetically characterized as Polycomb repressive deubiquitnase (PR-DUB) for unclear reasons. However, it remains a mystery whether and how PR-DUB deficiency affects chromatin states and cell fates through impaired PcG silencing. Here through a careful epigenomic analysis, we demonstrate that a bulk of H2AK119ub1 is diffusely distributed away from promoter regions and their enrichment is positively correlated with PRC1 occupancy. Upon deletion of Asxl2 in mouse embryonic stem cells (ESCs), a pervasive gain of H2AK119ub1 is coincident with increased PRC1 sampling at chromatin. Accordingly, PRC1 is significantly lost from a subset of highly occupied promoters, leading to impaired silencing of associated genes before and after lineage differentiation of Asxl2-null ESCs. Therefore, our study highlights the importance of genome-wide H2AK119ub1 restriction by PR-DUB in safeguarding robust PRC1 deposition and its roles in developmental regulation.
| S-EPMC10542648 | biostudies-literature
Project description:Polycomb group (PcG) proteins are critical chromatin regulators for cell fate control. The mono-ubiquitylation on histone H2AK119 (H2AK119ub1) is one of the well-recognized mechanisms for Polycomb Repressive Complex 1 (PRC1)-mediated transcription repression. However, the specific H2AK119 deubiquitylation complex composed by ASX-like proteins (ASXLs) and BAP1 has also been genetically characterized as a Polycomb Repressive complex (PR-DUB). Here we try to provide a rationale for these counterintuitive findings. Through re-examining the genomic distribution of H2AK119ub1, we find that H2AK119ub1 is non-negligibly distributed at non-promoter regions and associated with PRC1 sampling. Upon deletion of Asxl2 in mouse embryonic stem cells (ESCs), H2AK119ub1 is pervasively gained, especially at non-promoter regions, which is associated with increased RING1B occupancy. Meanwhile RING1B is significantly lost from a subset of the target promoters and thereby results in minor derepression in Asxl2-null ESCs. However notably, Asxl2 loss causes aberrant lineage differetiation, similar to PcG mutants. Therefore, our data reconcile seemingly paradoxical roles of PR-DUB on transcription repression and highlight the importance of a balanced H2AK119ub1 dynamics in developmental regulation.
2023-03-31 | GSE186374 | GEO
Project description:Polycomb group (PcG) proteins are critical chromatin regulators for cell fate control. The mono-ubiquitylation on histone H2AK119 (H2AK119ub1) is one of the well-recognized mechanisms for Polycomb Repressive Complex 1 (PRC1)-mediated transcription repression. However, the specific H2AK119 deubiquitylation complex composed by ASX-like proteins (ASXLs) and BAP1 has also been genetically characterized as a Polycomb Repressive complex (PR-DUB). Here we try to provide a rationale for these counterintuitive findings. Through re-examining the genomic distribution of H2AK119ub1, we find that H2AK119ub1 is non-negligibly distributed at non-promoter regions and associated with PRC1 sampling. Upon deletion of Asxl2 in mouse embryonic stem cells (ESCs), H2AK119ub1 is pervasively gained, especially at non-promoter regions, which is associated with increased RING1B occupancy. Meanwhile RING1B is significantly lost from a subset of the target promoters and thereby results in minor derepression in Asxl2-null ESCs. However notably, Asxl2 loss causes aberrant lineage differetiation, similar to PcG mutants. Therefore, our data reconcile seemingly paradoxical roles of PR-DUB on transcription repression and highlight the importance of a balanced H2AK119ub1 dynamics in developmental regulation.
2023-03-31 | GSE186373 | GEO
Project description:PR-DUB safeguards Polycomb repression through restricting H2AK119ub1
| PRJNA773657 | ENA
Project description:PR-DUB safeguards Polycomb repression through restricting H2AK119ub1 [ChIP-seq]
| PRJNA773660 | ENA
Project description:PR-DUB safeguards Polycomb repression through restricting H2AK119ub1 [RNA-seq]
| PRJNA773661 | ENA
Project description:This SuperSeries is composed of the SubSeries listed below.
2022-11-09 | GSE210236 | GEO
Project description:The Polycomb repressive complexes PRC1, PRC2, and PR-DUB repress target genes by modifying their chromatin. In Drosophila, PRC1 compacts chromatin and monoubiquitinates histone H2A at lysine 118 (H2Aub1), whereas PR-DUB is a major H2Aub1 deubiquitinase, but how H2Aub1 levels must be balanced for Polycomb repression remains unclear. We show that in early embryos, H2Aub1 is enriched at Polycomb target genes, where it facilitates H3K27me3 deposition by PRC2 to mark genes for repression. During subsequent stages of development, H2Aub1 becomes depleted from these genes and is no longer enriched when Polycomb maintains them repressed. Accordingly, Polycomb targets remain repressed in H2Aub1-deficient animals. In PR-DUB catalytic mutants, high levels of H2Aub1 accumulate at Polycomb target genes, and Polycomb repression breaks down. These high H2Aub1 levels do not diminish Polycomb protein complex binding or H3K27 trimethylation but increase DNA accessibility. We show that H2Aub1 interferes with nucleosome stacking and chromatin fiber folding in vitro. Consistent with this, Polycomb repression defects in PR-DUB mutants are exacerbated by reducing PRC1 chromatin compaction activity, but Polycomb repression is restored if PRC1 E3 ligase activity is removed. PR-DUB therefore acts as a rheostat that removes excessive H2Aub1 that, although deposited by PRC1, antagonizes PRC1-mediated chromatin compaction.
| S-EPMC9744231 | biostudies-literature
Project description:Polycomb group (PcG) proteins are transcriptional repressors that control processes ranging from the maintenance of cell fate decisions and stem cell pluripotency in animals to the control of flowering time in plants. In Drosophila, genetic studies identified more than 15 different PcG proteins that are required to repress homeotic (HOX) and other developmental regulator genes in cells where they must stay inactive. Biochemical analyses established that these PcG proteins exist in distinct multiprotein complexes that bind to and modify chromatin of target genes. Among those, Polycomb repressive complex 1 (PRC1) and the related dRing-associated factors (dRAF) complex contain an E3 ligase activity for monoubiquitination of histone H2A (refs 1-4). Here we show that the uncharacterized Drosophila PcG gene calypso encodes the ubiquitin carboxy-terminal hydrolase BAP1. Biochemically purified Calypso exists in a complex with the PcG protein ASX, and this complex, named Polycomb repressive deubiquitinase (PR-DUB), is bound at PcG target genes in Drosophila. Reconstituted recombinant Drosophila and human PR-DUB complexes remove monoubiquitin from H2A but not from H2B in nucleosomes. Drosophila mutants lacking PR-DUB show a strong increase in the levels of monoubiquitinated H2A. A mutation that disrupts the catalytic activity of Calypso, or absence of the ASX subunit abolishes H2A deubiquitination in vitro and HOX gene repression in vivo. Polycomb gene silencing may thus entail a dynamic balance between H2A ubiquitination by PRC1 and dRAF, and H2A deubiquitination by PR-DUB.
| S-EPMC3182123 | biostudies-literature
Project description:Polycomb group proteins are important for maintaining gene expression patterns and cell identity in metazoans. The mammalian Polycomb repressive deubiquitinase (PR-DUB) complexes catalyze removal of monoubiquitination on lysine 119 of histone H2A (H2AK119ub1) through a multiprotein core comprised of BAP1, HCFC1, FOXK1/2, and OGT in combination with either of ASXL1, 2, or 3. Mutations in PR-DUB components are frequent in cancer. However, mechanistic understanding of PR-DUB function in gene regulation is limited. Here, we show that BAP1 is dependent on the ASXL proteins and FOXK1/2 in facilitating gene activation across the genome. Although PR-DUB was previously shown to cooperate with PRC2, we observed minimal overlap and functional interaction between BAP1 and PRC2 in embryonic stem cells. Collectively, these results demonstrate that PR-DUB, by counteracting accumulation of H2AK119ub1, maintains chromatin in an optimal configuration ensuring expression of genes important for general functions such as cell metabolism and homeostasis.
| S-EPMC7462075 | biostudies-literature