The cohesin associated factor Wapal is required for proper polycomb-mediated gene silencing
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE63325 | GEO | 2016/03/21
SECONDARY ACCESSION(S): PRJNA267500
REPOSITORIES: GEO
Similar Datasets
Project description:BackgroundThe cohesin complex consists of multiple core subunits that play critical roles in mitosis and transcriptional regulation. The cohesin-associated protein Wapal plays a central role in off-loading cohesin to facilitate sister chromatid separation, but its role in regulating mammalian gene expression is not understood. We used embryonic stem cells as a model, given that the well-defined transcriptional regulatory circuits were established through master transcription factors and epigenetic pathways that regulate their ability to maintain a pluripotent state.ResultsRNAi-mediated depletion of Wapal causes a loss of pluripotency, phenocopying loss of core cohesin subunits. Using chromatin immunoprecipitation coupled with next-generation sequencing (ChIP-seq), we determine that Wapal occupies genomic sites distal to genes in combination with CTCF and core cohesin subunits such as Rad21. Interestingly, genomic sites occupied by Wapal appear enriched for cohesin, implying that Wapal does not off-load cohesin at regions it occupies. Wapal depletion induces derepression of Polycomb group (PcG) target genes without altering total levels of Polycomb-mediated histone modifications, implying that PcG enzymatic activity is preserved. By integrating ChIP-seq and gene expression changes data, we identify that Wapal binding is enriched at the promoters of PcG-silenced genes and is required for proper Polycomb repressive complex 2 (PRC2) recruitment. Lastly, we demonstrate that Wapal is required for the interaction of a distal cis-regulatory element (CRE) with the c-Fos promoter.ConclusionsCollectively, this work indicates that Wapal plays a critical role in silencing of PcG target genes through the interaction of distal CREs with promoters.
| S-EPMC4832553 | biostudies-literature
Project description:The cohesin offloading protein Wapal also acts as a polycomb factor in flies. We examined its role in transcriptional role in murine embryonic stem cells (ESCs)
2016-03-21 | GSE63291 | GEO
Project description:The cohesin offloading protein Wapal also acts as a polycomb factor in flies. We examined its role in transcriptional role in murine embryonic stem cells (ESCs)
2016-03-21 | GSE63324 | GEO
Project description:The cohesin associated factor Wapal is required for proper polycomb-mediated gene silencing
| PRJNA267500 | ENA
Project description:The cohesin complex consists of multiple core subunits that play critical roles in mitosis and transcriptional regulation. The cohesin-associated protein Wapal plays a central role in offloading cohesin to facilitate sister chromatid separation, but its role in regulating mammalian gene expression is not understood. We used embryonic stem cells (ESCs) as a model given the well-defined transcriptional regulatory circuits established through master transcription factors and epigenetic pathways that regulate their ability to maintain a pluripotent state. RNAi-mediated depletion of Wapal causes a loss of pluripotency, phenocopying loss of core cohesin subunits. Using chromatin immunoprecipitation coupled with next-generation sequencing (ChIP-seq) we determine that Wapal occupies genomic sites distal to genes in combination with CTCF and core cohesin subunits such as Rad21. Interestingly, genomic sites occupied by Wapal appear enriched for cohesin, implying Wapal does not offload cohesin at regions it occupies. Wapal depletion induces derepression of Polycomb Group (PcG) target genes without altering total levels of Polycomb-mediated histone modifications, implying that PcG enzymatic activity is preserved. By integrating ChIP-seq and gene expression changes data we identify that Wapal binding is enriched at the promoters of PcG silenced genes and is required for proper Polycomb Repressive Complex 2 (PRC2) recruitment. Lastly, we demonstrate that Wapal is required for the interaction of a distal cis-regulatory element (CRE) with the c-Fos promoter. Collectively, this work indicates that Wapal plays a critical role in silencing of PcG target genes through the interaction of distal CREs with promoters.
2016-03-21 | GSE78826 | GEO
Project description:This SuperSeries is composed of the SubSeries listed below. Refer to individual Series
2015-02-23 | E-GEOD-63518 | biostudies-arrayexpress
Project description:Wapl protein regulates binding of the cohesin complex to chromosomes during interphase and helps remove cohesin from chromosomes at mitosis. We isolated a dominant mutation in wapl (wapl(AG)) in a screen for mutations that counteract silencing mediated by an engrailed Polycomb-group response element. wapl(AG) hemizygotes die as pharate adults and have an extra sex combs phenotype characteristic of males with mutations in Polycomb-group (PcG) genes. The wapl gene encodes two proteins, a long form and a short form. wapl(AG) introduces a stop codon at amino acid 271 of the long form and produces a truncated protein. The expression of a transgene encoding the truncated Wapl-AG protein causes an extra-sex-comb phenotype similar to that seen in the wapl(AG) mutant. Mutations in the cohesin-associated genes Nipped-B and pds5 suppress and enhance wapl(AG) phenotypes, respectively. A Pds5-Wapl complex (releasin) removes cohesin from DNA, while Nipped-B loads cohesin. This suggests that Wapl-AG might exert its effects through changes in cohesin binding. Consistent with this model, Wapl-AG was found to increase the stability of cohesin binding to polytene chromosomes. Our data suggest that increasing cohesin stability interferes with PcG silencing at genes that are co-regulated by cohesin and PcG proteins.
| S-EPMC3478686 | biostudies-literature
Project description:This SuperSeries is composed of the SubSeries listed below. Refer to individual Series
2014-01-03 | E-GEOD-46545 | biostudies-arrayexpress
Project description:BackgroundEpigenetic memory plays a critical role in the establishment and maintenance of cell identities in multicellular organisms. Polycomb and trithorax group (PcG and TrxG) proteins are responsible for epigenetic memory, and in flies, they are recruited to specialized DNA regulatory elements termed polycomb response elements (PREs). Previous transgene studies have shown that PREs can silence reporter genes outside of their normal context, often by pairing sensitive (PSS) mechanism; however, their silencing activity is non-autonomous and depends upon the surrounding chromatin context. It is not known why PRE activity depends on the local environment or what outside factors can induce silencing.ResultsUsing an attP system in Drosophila, we find that the so-called neutral chromatin environments vary substantially in their ability to support the silencing activity of the well-characterized bxdPRE. In refractory chromosomal contexts, factors required for PcG-silencing are unable to gain access to the PRE. Silencing activity can be rescued by linking the bxdPRE to a boundary element (insulator). When placed next to the PRE, the boundaries induce an alteration in chromatin structure enabling factors critical for PcG silencing to gain access to the bxdPRE. When placed at a distance from the bxdPRE, boundaries induce PSS by bringing the bxdPREs on each homolog in close proximity.ConclusionThis proof-of-concept study demonstrates that the repressing activity of PREs can be induced or enhanced by nearby boundary elements.
| S-EPMC8170967 | biostudies-literature
Project description:Polycomb group (PcG) proteins are conserved chromatin regulators involved in the control of key developmental programs in eukaryotes. They collectively provide the transcriptional memory unique to each cell identity by maintaining transcriptional states of developmental genes. PcG proteins form multi-protein complexes, known as Polycomb repressive complex 1 (PRC1) and Polycomb repressive complex 2 (PRC2). PRC1 and PRC2 contribute to the stable gene silencing in part through catalyzing covalent histone modifications. Components of PRC1 and PRC2 are well conserved from plants to animals. PcG-mediated gene silencing has been extensively investigated in efforts to understand molecular mechanisms underlying developmental programs in eukaryotes. Here, we describe our current knowledge on PcG-mediated gene repression which dictates developmental programs by dynamic layers of regulatory activities, with an emphasis given to the model plant Arabidopsis thaliana.
| S-EPMC4275700 | biostudies-literature