Genome wide analysis of binding of Polyhomeotic and polymerization defective Polyhomeotic in Drosophila S2 cells
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ABSTRACT:
ORGANISM(S): Drosophila melanogaster
PROVIDER: GSE60686 | GEO | 2016/03/08
SECONDARY ACCESSION(S): PRJNA259244
REPOSITORIES: GEO
Similar Datasets
Project description:To understand the role of the conserved Sterile Alpha Motif of the Polycomb Group protein Polyhomeotic, the genome wide distribution of wild type and polymerization defective Polyhomeotic containing mutations in the SAM domain was determined by ChIP-SEQ. ChIP-seq Identification of polyhomeotic wild type (PH-WT) and mutant (PH-ML) binding sites.
2016-03-08 | E-GEOD-60686 | biostudies-arrayexpress
Project description:Chromatin in eukaryotic nuclei is organized at multiple scales, from individual nucleosomes to specific loops between regulatory sequences, to the folding of large genomic regions into topological domains and segregation of whole chromosomes into territories. Many of the chromatin proteins that regulate this architecture, including the essential Polycomb Group (PcG) proteins, are themselves organized into subnuclear structures. Deciphering mechanistic links between protein organization and genome architecture requires precise description and mechanistic perturbations of both. Using super-resolution microscopy, we characterized the nanoscale organization of PcG proteins in Drosophila cells and find hundreds of small protein clusters, distinct from the large PcG bodies present in just a few copies per cell that have been the focus of previous investigations. We manipulated PcG clusters either by disrupting the polymerization activity of the conserved Sterile Alpha Motif (SAM) of the PcG protein Polyhomeotic (Ph) or increasing Ph levels in Drosophila S2 cells. Disrupting clustering using Ph SAM mutations disrupts chromatin interactions on scales from 50kb to 13Mb while increasing Ph levels increases both cluster number and long range chromatin interactions. RNA-seq and qPCR indicate that both perturbations also alter expression levels of many genes. Molecular simulations suggest a model in which PcG cluster formation on chromatin is governed by the kinetics of association between Ph SAMs and PcG cluster size is bounded by the affinity and occupancy of chromatin binding sites. Our results suggest that nanoscale organization of PcG proteins into small, abundant clusters on chromatin through the polymerization activity of Ph SAM shapes genome architecture by mediating numerous long-range chromatin interactions.
2016-01-14 | GSE72830 | GEO
Project description:The Polycomb protein Polyhomeotic (Ph) is implicated in organizing chromatin to regulate gene expression. This activity depends on the sterile alpha motif in Ph, which can form helical polymers. This polymerization activity is believed to create macromolecular assemblies of Polycomb proteins and chromatin in cells. To understand how this may occur, and the possible role of phase separation in the process, we analyzed a truncated version of Ph (aa1289-1577, Mini-Ph) in vitro. We find that Mini-Ph forms phase separated condensates with DNA or chromatin in vitro. To understand how Ph SAM polymerization contributes to this activity, and how Mini-Ph conformation might change on binding DNA and phase separating, we used a protein footprinting method based on chemical acetylation of accessible lysine residues. Mini-Ph or a polymerization mutant, alone, or with DNA, was treated with sulfo-NHS-acetate to acetylate accessible lysines. After protein denaturation, the protein was treated with propionic acid to propionylate unacetylated lysines. Samples were analyzed by MS, and the ratio of acetylated/propionylated lysines quantified at each position using MaxQuant.
2020-07-10 | MSV000085717 | MassIVE
Project description:Polycomb group (PcG) proteins mediate heritable but reversible silencing of developmental regulator genes by modifying their chromatin configuration. Accumulating evidence documents a role for PcG proteins in regulating higher order chromatin structures likely by their clustering, however, underlying mechanisms and its impact on transcriptional regulation remain obscure. In this study, we found that subnuclear clustering of PRC1 at canonical PcG target genes depended on head-to-tail polymerization property of SAM domain of Phc2 and likely Phc1. We show that Phc2-SAM polymerization limits the dynamic nature of PRC1, thereby promotes stable association of PRC1 with PcG target genes and contributes to their robust silencing. Our findings suggest a novel model by which SAM polymerization of Phc2 modulates the structural organization of PcG complexes to enable robust yet reversible PcG-mediated repression during development.
2013-06-01 | GSE37530 | GEO
Project description:Polycomb group (PcG) proteins mediate heritable but reversible silencing of developmental regulator genes by modifying their chromatin configuration. Accumulating evidence documents a role for PcG proteins in regulating higher order chromatin structures likely by their clustering, however, underlying mechanisms and its impact on transcriptional regulation remain obscure. In this study, we found that subnuclear clustering of PRC1 at canonical PcG target genes depended on head-to-tail polymerization property of SAM domain of Phc2 and likely Phc1. We show that Phc2-SAM polymerization limits the dynamic nature of PRC1, thereby promotes stable association of PRC1 with PcG target genes and contributes to their robust silencing. Our findings suggest a novel model by which SAM polymerization of Phc2 modulates the structural organization of PcG complexes to enable robust yet reversible PcG-mediated repression during development.
2013-06-01 | GSE37346 | GEO
Project description:Polycomb group (PcG) proteins mediate heritable but reversible silencing of developmental regulator genes by modifying their chromatin configuration. Accumulating evidence documents a role for PcG proteins in regulating higher order chromatin structures likely by their clustering, however, underlying mechanisms and its impact on transcriptional regulation remain obscure. In this study, we found that subnuclear clustering of PRC1 at canonical PcG target genes depended on head-to-tail polymerization property of SAM domain of Phc2 and likely Phc1. We show that Phc2-SAM polymerization limits the dynamic nature of PRC1, thereby promotes stable association of PRC1 with PcG target genes and contributes to their robust silencing. Our findings suggest a novel model by which SAM polymerization of Phc2 modulates the structural organization of PcG complexes to enable robust yet reversible PcG-mediated repression during development.
2013-06-01 | GSE37526 | GEO
Project description:Polycomb group (PcG) proteins mediate heritable but reversible silencing of developmental regulator genes by modifying their chromatin configuration. Accumulating evidence documents a role for PcG proteins in regulating higher order chromatin structures likely by their clustering, however, underlying mechanisms and its impact on transcriptional regulation remain obscure. In this study, we found that subnuclear clustering of PRC1 at canonical PcG target genes depended on head-to-tail polymerization property of SAM domain of Phc2 and likely Phc1. We show that Phc2-SAM polymerization limits the dynamic nature of PRC1, thereby promotes stable association of PRC1 with PcG target genes and contributes to their robust silencing. Our findings suggest a novel model by which SAM polymerization of Phc2 modulates the structural organization of PcG complexes to enable robust yet reversible PcG-mediated repression during development. Examination of H3K27me3 in wild type and the Phc2 mutant cells
2013-06-01 | E-GEOD-37530 | biostudies-arrayexpress
Project description:Polycomb group (PcG) proteins mediate heritable but reversible silencing of developmental regulator genes by modifying their chromatin configuration. Accumulating evidence documents a role for PcG proteins in regulating higher order chromatin structures likely by their clustering, however, underlying mechanisms and its impact on transcriptional regulation remain obscure. In this study, we found that subnuclear clustering of PRC1 at canonical PcG target genes depended on head-to-tail polymerization property of SAM domain of Phc2 and likely Phc1. We show that Phc2-SAM polymerization limits the dynamic nature of PRC1, thereby promotes stable association of PRC1 with PcG target genes and contributes to their robust silencing. Our findings suggest a novel model by which SAM polymerization of Phc2 modulates the structural organization of PcG complexes to enable robust yet reversible PcG-mediated repression during development.
2013-08-07 | GSE42801 | GEO
Project description:Polycomb group (PcG) proteins mediate heritable but reversible silencing of developmental regulator genes by modifying their chromatin configuration. Accumulating evidence documents a role for PcG proteins in regulating higher order chromatin structures likely by their clustering, however, underlying mechanisms and its impact on transcriptional regulation remain obscure. In this study, we found that subnuclear clustering of PRC1 at canonical PcG target genes depended on head-to-tail polymerization property of SAM domain of Phc2 and likely Phc1. We show that Phc2-SAM polymerization limits the dynamic nature of PRC1, thereby promotes stable association of PRC1 with PcG target genes and contributes to their robust silencing. Our findings suggest a novel model by which SAM polymerization of Phc2 modulates the structural organization of PcG complexes to enable robust yet reversible PcG-mediated repression during development. Wild type and Phc2L307R/L307R MEFs were used for RNA extraction and hybridization on Affymetrix microarrays.
2013-06-01 | E-GEOD-37346 | biostudies-arrayexpress
Project description:Polycomb group (PcG) proteins mediate heritable but reversible silencing of developmental regulator genes by modifying their chromatin configuration. Accumulating evidence documents a role for PcG proteins in regulating higher order chromatin structures likely by their clustering, however, underlying mechanisms and its impact on transcriptional regulation remain obscure. In this study, we found that subnuclear clustering of PRC1 at canonical PcG target genes depended on head-to-tail polymerization property of SAM domain of Phc2 and likely Phc1. We show that Phc2-SAM polymerization limits the dynamic nature of PRC1, thereby promotes stable association of PRC1 with PcG target genes and contributes to their robust silencing. Our findings suggest a novel model by which SAM polymerization of Phc2 modulates the structural organization of PcG complexes to enable robust yet reversible PcG-mediated repression during development. Examination of Ring1B in wild type and the Phc2 mutant cells
2013-08-07 | E-GEOD-42801 | biostudies-arrayexpress