Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Dispersal of PRC1 condensates disrupts polycomb chromatin domains and loops

ABSTRACT: Polycomb-repressive complex 1 (PRC1) has a constraining influence on 3D genome organization, mediating localized and chromosome-wide clustering of target loci. Polycomb-bound regions form transcriptionally repressive chromatin domains independent of topologically associating domains (TADs). Several subunits of PRC1 have the capacity to form biomolecular condensates through liquid-liquid phase separation (LLPS) in vitro and when tagged and over-expressed in cells. Here, we use 1,6 hexandiol (1,6-HD), which disrupts liquid-like condensates, to examine the role of endogenous PRC1 biomolecular condensates on local and chromosome-wide clustering of PRC1-bound loci. Using imaging and chromatin immunoprecipitation combined with deep sequencing (ChIP-seq) analyses, we show that PRC1-mediated localized chromatin compaction and clustering of targeted genomic loci at megabase and tens of megabase scales can be reversibly disrupted by the addition and subsequent removal of 1,6-HD to mouse embryonic stem cells (mESCs). Decompaction and dispersal of polycomb domains and clusters cannot be solely attributable to the reduction of PRC1 binding following 1,6-HD treatment as the addition of 2,5-HD has similar effects despite this alcohol not perturbing PRC1-mediated clustering, at least at the sub-megabase and megabase scales. These results suggest that weak, hydrophobic interactions between PRC1 molecules characteristic of liquid condensates do have a role in polycomb-mediated genome organization.

ORGANISM(S): Mus musculus Homo sapiens

PROVIDER: GSE224930 | GEO | 2023/02/13

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Similar Datasets

Suppression of liquid-liquid phase separation by 1,6-hexanediol partially compromises the 3D genome organization in living cells

Project description:Liquid-liquid phase separation (LLPS) contributes to the spatial and functional segregation of molecular processes within the cell nucleus. However, the role played by LLPS in chromatin folding in living cells remains unclear. Here, using stochastic optical reconstruction microscopy (STORM) and Hi-C techniques, we studied the effects of 1,6-hexanediol (1,6-HD)- mediated LLPS disruption/modulation on higher-order chromatin organization in living cells. We found that 1,6-HD treatment caused the enlargement of nucleosome clutches and their more uniform distribution in the nuclear space. At a megabase-scale, chromatin underwent moderate but irreversible perturbations that resulted in the partial mixing of A and B compartments. The removal of 1,6-HD from the culture medium did not allow chromatin to acquire initial configurations, and resulted in more compact repressed chromatin than in untreated cells. 1,6-HD treatment also weakened enhancer-promoter interactions and TAD insulation but did not considerably affect CTCF-dependent loops. Our results suggest that 1,6-HD-sensitive LLPS plays a limited role in chromatin spatial organization by constraining its folding patterns and facilitating compartmentalization at different levels.

2021-03-22 | GSE138543 | GEO

Eukaryotic cytoplasm is widely structured via mesoscale condensates

Project description:Compartmentalization is an essential feature of eukaryotic life and is achieved both via membrane-bound organelles, such as mitochondria, and membrane-less biomolecular condensates, such as the nucleolus. Known biomolecular condensates typically exhibit liquid-like properties and are visualized by microscopy on the scale of ~1µm. They have been studied mostly by microscopy, examining select individual proteins. So far, several dozen biomolecular condensates are known, serving a multitude of functions, for example, in the regulation of transcription, RNA processing or signalling and their malfunction can cause diseases. However, it remains unclear to what extent biomolecular condensates are utilized in cellular organization and at what length scale they typically form. Here we examine native cytoplasm from Xenopus egg extract on a global scale with quantitative proteomics, filtration, size exclusion and dilution experiments. These assays reveal that at least 18% of the proteome is organized into mesoscale biomolecular condensates at the scale of ~100nm and appear to be stabilized by RNA or gelation. We confirmed mesoscale sizes via imaging below the diffraction limit by investigating protein permeation into porous substrates with defined pore sizes. Our results show that eukaryotic cytoplasm organizes extensively via biomolecular condensates, but at surprisingly short length scales.

2023-11-02 | GSE232651 | GEO

Project description:Time-dependent Effect of 1,6-hexanediol on Biomolecular Condensates and 3D Chromatin Organization

| PRJNA665281 | ENA

Long-distance association of topological boundaries through nuclear condensates (ChIP-Seq)

Project description:Chromatin is partitioned into distinct topological domains in an activity-dependent manner, with topological boundaries limiting the interaction between adjacent domains. Recent studies support the concept that several well-established nuclear compartments are assembled as ribonucleoprotein condensates. Here we ask whether the physical processes driving the assembly of the nuclear condensates play any role in three-dimensional chromatin architecture. We report that the insulation of approximately 20% of topological boundaries in human embryonic stem cells is substantially weakened following brief treatment with 1,6-hexanediol, a chemical known to disrupt several nuclear condensates. The disrupted boundaries are characterized by a high level of transcription, striking spatial clustering, and the augmented presence of transcription units widely expressed in diverse cell types. These topological boundary regions tend to be spatially associated, even inter-chromosomally, and segregate with nuclear speckles. These observations reveal a previously unappreciated mode of genome organization mediated by conserved boundary elements harboring widely-expressed transcription units and associated transcriptional condensates.

2022-06-15 | GSE195561 | GEO

Long-distance association of topological boundaries through nuclear condensates (Hi-C)

2022-06-15 | GSE195565 | GEO

Long-distance association of topological boundaries through nuclear condensates (GRO-Seq)

2022-06-15 | GSE195562 | GEO

Long-distance association of topological boundaries through nuclear condensates (PRO-Seq)

2022-06-15 | GSE195563 | GEO

SRRM2 Phase Separation Drives Assembly of Nuclear Speckle Subcompartments

Project description:Nuclear speckles (NSs) are nuclear biomolecular condensates that are postulated to arise through liquid-liquid phase separation (LLPS), although the detailed underlying forces driving NS formation remain elusive. SRRM2 and SON are 2 non-redundant scaffold proteins for NSs. How each individual protein governs assembly of NS protein network and the functional relationship between SRRM2 and SON are largely unknown. Here, we uncover immiscible multiphase of SRRM2 and SON within NSs. SRRM2 and SON are functionally independent, specifically regulating alternative splicing of subsets of mRNA targets, respectively. We further uncover that SRRM2 forms multicomponent liquid phase in cells to drive NS subcompartmentalization, which is reliant on homotypic interaction and heterotypic non-selective protein-RNA complex coacervation-driven multicomponent LLPS. SRRM2 RS domains form high-order oligomers, and can be replaced by oligomerizable synthetic modules, the serine residues within the RS domains, however, play an irreplaceable role in fine-tuning the liquidity of NSs.

2024-01-31 | GSE242898 | GEO

Phosphorylation regulates viral biomolecular condensates to promote infectious progeny production

Project description:Biomolecular condensates play important roles in diverse biological processes. Many viruses form biomolecular condensates which have been implicated in various functions critical for productive infection of host cells. The adenovirus L1-52/55 kilodalton protein (52K) was recently shown to form viral biomolecular condensates that coordinate viral genome packaging and capsid assembly. Although critical for packaging, we do not know how viral condensates are regulated during adenovirus infection. Here we show that phosphorylation of serine residues 28 and 75 within the N-terminal intrinsically disordered region of 52K modulates viral condensates in vitro and in cells, promoting liquid-like properties over condensate hardening. Furthermore, we demonstrate that phosphorylation of 52K promotes viral genome packaging and production of infectious progeny particles. Collectively, our findings provide insights into how viral condensate properties are regulated and maintained in a state conducive to their function in viral progeny production. In addition, our findings have implications for antiviral strategies aimed at targeting the regulation of viral biomolecular condensates to limit viral multiplication.

2023-12-06 | PXD046971 | Pride

Mapping polycomb complexes in human and mouse embryonic stem cells

Project description:In embryonic stem (ES) cells, bivalent chromatin domains with overlapping repressive (H3 lysine 27 tri-methylation) and activating (H3 lysine 4 tri-methylation) histone modifications mark the promoters of more than 2000 genes. To gain insight into the structure and function of bivalent domains, we mapped key histone modifications and subunits of Polycomb repressive complexes 1 and 2 (PRC1 and PRC2) genomewide in human and mouse ES cells by chromatin immunoprecipitation followed by ultra high-throughput sequencing. We find that bivalent domains can be segregated into two classes: the first occupied by both PRC2 and PRC1 (PRC1-positive) and the second specifically bound by PRC2 (PRC2-only). PRC1-positive bivalent domains appear functionally distinct as they more efficiently retain lysine 27 tri-methylation upon differentiation, show stringent conservation of chromatin state, and associate with an overwhelming number of developmental regulator gene promoters. We also used computational genomics to search for sequence determinants of Polycomb binding. This analysis revealed that the genomewide locations of PRC2 and PRC1 can be largely predicted from the locations, sizes and underlying motif contents of CpG islands. We propose that large CpG islands depleted of activating motifs confer epigenetic memory by recruiting the full repertoire of Polycomb complexes. Keywords: cell type comparison Suz12, Ezh2, Ring1b ChIP-Seq in singlicate from mouse embryonic stem (mES) cells. H3K4me3, H3K27me3, H3K36me3, Ezh2 and Ring1b ChIP-Seq in singlicate from human embyonic stem cells (hES; H9).

2008-11-01 | E-GEOD-13084 | biostudies-arrayexpress

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data