Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

A biophysical basis for the diffusion-restricted behavior of Xist RNA

ABSTRACT: Here we reveal a biophysical basis for the spreading behavior of Xist RNA on the inactive X-chromosome (Xi). Xist and HNRNPK together drive a liquid-liquid phase separation (LLPS) that encapsulates the Xi. HNRNPK and Xist exert mutual pulling forces that lead to RNA internalization into the condensate. While HNRNPK is sufficient for condensate formation, Xist induces a further phase transition into a "soft" droplet by altering elasticity, adhesiveness, and wetting properties of the condensate in vitro. Once phase transition occurs, other Xist-interacting factors are internalized and concentrated within the condensate. We attribute LLPS to HNRNPK's RGG and Xist's Repeat B (RepB) motifs. Mutating these motifs causes Xist diffusion, disrupts Polycomb recruitment, and precludes the required mixing of Xi chromatin for establishing the Xi superstructure. Thus, phase transitions driven by RepB and HNRNPK create a membrane-less subnuclear compartment for the localization and limited diffusion of Xist ribonucleoprotein complexes on the Xi.

ORGANISM(S): Mus musculus

PROVIDER: GSE212696 | GEO | 2025/01/17

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

A biophysical basis for the spreading behavior and limited diffusion of Xist [ChIP-Seq]

Project description:Here we reveal a biophysical basis for the spreading behavior of Xist RNA on the inactive X-chromosome (Xi). Xist and HNRNPK together drive a liquid-liquid phase separation (LLPS) that encapsulates the Xi. HNRNPK and Xist exert mutual pulling forces that lead to RNA internalization into the condensate. While HNRNPK is sufficient for condensate formation, Xist induces a further phase transition into a "soft" droplet by altering elasticity, adhesiveness, and wetting properties of the condensate in vitro. Once phase transition occurs, other Xist-interacting factors are internalized and concentrated within the condensate. We attribute LLPS to HNRNPK's RGG and Xist's Repeat B (RepB) motifs. Mutating these motifs causes Xist diffusion, disrupts Polycomb recruitment, and precludes the required mixing of Xi chromatin for establishing the Xi superstructure. Thus, phase transitions driven by RepB and HNRNPK create a membrane-less subnuclear compartment for the localization and limited diffusion of Xist ribonucleoprotein complexes on the Xi.

2025-01-17 | GSE273578 | GEO

A biophysical basis for the spreading behavior and limited diffusion of Xist [CHART-seq]

2025-01-17 | GSE273564 | GEO

A biophysical basis for the spreading behavior and limited diffusion of Xist [RNA-Seq]

2025-01-17 | GSE273563 | GEO

Xist RNA targets selective autosomal genes to modulate expression in a Repeat B-dependent manner [RNA-seq]

Project description:Xist, a pivotal player in X chromosome inactivation (XCI), has long been perceived as a cis-acting long noncoding RNA that binds exclusively to the inactive X chromosome (Xi). However, Xist’s ability to diffuse under select circumstances has long been documented, leading us to suspect that Xist RNA may have targets and functions beyond the Xi. Here, using female mouse embryonic stem cells (ES) and mouse embryonic fibroblasts (MEF) as a model, we demonstrate that Xist RNA indeed can spread beyond the Xi. However, its binding is limited to ~100 genes in differentiating ES and MEF cells. The target genes are diverse in function but are unified by their active chromatin status. Although active, Xist binding is associated with a downregulation of gene expression. Unlike on the Xi, Xist binding does not lead to full silencing and also does not spread beyond the target gene. Deleting Xist’s Repeat B (RepB) domain reduces Xist’s diffusion away from the Xi and inhibits Xist’s localization to autosomal targets. Nonetheless, Xist transcript lacking RepB fails to down-modulate autosomal gene expression. Altogether, our findings reveal Xist targets beyond the Xi and identify Repeat B as a crucial domain for its in-trans function.

2024-08-23 | GSE271097 | GEO

Xist RNA targets selective autosomal genes to modulate expression in a Repeat B-dependent manner [CHART-seq]

2024-08-23 | GSE271096 | GEO

An Xist-dependent protein assembly mediates Xist localization and gene silencing

Project description:Nuclear compartments play diverse roles in regulating gene expression, yet the molecular forces and components driving compartment formation are not well understood. Studying how the lncRNA Xist establishes the inactive-X-chromosome (Xi)-compartment, we found that the Xist RNA-binding-proteins PTBP1, MATR3, TDP43, and CELF1 form a condensate to create an Xi-domain that can be sustained in the absence of Xist. The E-repeat-sequence of Xist serves a multivalent binding-platform for these proteins. Without the E-repeat, Xist initially coats the X-chromosome during XCI onset but subsequently disperses across the nucleus with loss of gene silencing. Recruitment of PTBP1, MATR3, TDP-43 or CELF1 to E-Xist rescues these phenotypes, and requires both self-association of MATR3 and TDP-43 and a heterotypic PTBP1-MATR3-interaction. Together, our data reveal that Xist sequesters itself within the Xi-territory and perpetuates gene silencing by seeding a protein-condensate. Our findings uncover an unanticipated mechanism for epigenetic memory and elucidate the interplay between RNA and RNA-binding-proteins in creating compartments for gene regulation.

2020-09-03 | GSE137305 | GEO

Xist Deletional Analysis Reveals an Interdependency between Xist RNA and Polycomb Complexes for Spreading along the Inactive X

Project description:During X-inactivation, Xist RNA spreads along an entire chromosome to establish silencing. However, the mechanism and functional RNA elements involved in spreading remain undefined. By performing a comprehensive endogenous Xist deletion screen, we identify Repeat B as crucial for spreading Xist and maintaining Polycomb repressive complexes 1 and 2 (PRC1/PRC2) along the inactive X (Xi). Unexpectedly, spreading of these three factors is inextricably linked. Deleting Repeat B or its direct binding partner, HNRNPK, compromises recruitment of PRC1 and PRC2. In turn, ablating PRC1 or PRC2 impairs Xist spreading. Therefore, Xist and Polycomb complexes require each other to propagate along the Xi, suggesting a positive feedback mechanism between RNA initiator and protein effectors. Perturbing Xist/Polycomb spreading causes failure of de novo Xi silencing, with partial compensatory downregulation of the active X, and also disrupts topological Xi reconfiguration. Thus, Repeat B is a multifunctional element that integrates interdependent Xist/ Polycomb spreading, silencing, and changes in chromosome architecture.

2019-03-01 | GSE107217 | GEO

Unfolding the inactive X chromosome

Project description:The inactive X chromosome (Xi) is folded in a stepwise process into a compartment-less structure. Here we investigate if the Xi can be unfolded in post-XCI cells. We began with ablating structural maintenance of chromosomes hinge domain containing 1 (Smchd1) in female mouse embryonic fibroblasts (MEFs), a cell type in which XCI is completed. We then performed in situ Hi-C on one Smchd1+/+ (wild-type, WT) and one Smchd1-/- (knockout, KO) MEF clone to probe the role of SMCHD1 in maintaining the higher-order structure of the Xi. To determine if the change in chromosome structure is accompanied by altered gene expression, we performed RNA-seq on two WT and two independently generated Smchd1-/- clones treated with either DMSO or 5-aza-2'-deoxycytidine (Aza), a DNA demethylating agent. In addition, we performed H3K27me3 and H2AK119ub ChIP-seq and Xist Capture Hybridization Analysis of RNA Targets with deep sequencing (CHART-seq) on one WT and one Smchd1-/- MEF clone to determine if there is an alteration in the epigenetic state of the Smchd1-/- Xi. Finally, we examined the role of Xist, Polycomb repressive complex 1 (PRC1), and Heterogeneous Nuclear Ribonucleoprotein K (HNRNPK) in regulating the Xi structure in post-XCI cells. To do so we performed in situ Hi-C on WT and Smchd1-/- MEFs depleted with either PRC1 or HNRNPK, as well as on fibroblasts in which Xist is deleted on the Xi (XidelXist).

2019-05-03 | GSE116413 | GEO

A comprehensive Xist interactome reveals cohesin repulsion and an RNA-directed chromosome conformation

Project description:The inactive X chromosome (Xi) serves as a model to understand gene silencing on a global scale. Here, we perform identification of direct RNA interacting proteins? (iDRiP) to isolate a comprehensive protein interactome for Xist, an RNA required for Xi silencing. We discover multiple classes of interactors, including cohesins, condensins, topoisomerases, RNA helicases, chromatin remodelers and modifiers, which synergistically repress Xi transcription. Inhibiting two or three interactors destabilizes silencing. While Xist attracts some interactors, it repels architectural factors. Xist evicts cohesins from the Xi and directs an Xi-specific chromosome conformation. Upon deleting Xist, the Xi acquires the cohesin-binding and chromosomal architecture of the active X. Our study unveils many layers of Xi repression and demonstrates a central role for RNA in the topological organization of mammalian chromosomes. The RNA-seq data sets generated in this study provide a resource for examining the effects of knockdowns of various Xist-interacting proteins on gene expression. The ChIP-seq data sets provide a comprehensive set of data examining CTCF and cohesion binding the X-chromosome, and the effects of deleting Xist on CTCF and cohesion binding. The Hi-C data is an allele-specific contact map of the X-chromosome higher-order chromatin structure in mouse. RNA-seq in 3 control and 10 knockdown cell lines. ChIP-seq for CTCF, Rad21 and Smc1a in wild-type fibroblasts and Xist-deletion fibroblasts. Hi-C in wild-type and Xist-deletion fibroblasts.

2015-06-19 | E-GEOD-67516 | biostudies-arrayexpress

Xist RNA regulates remodeling of the Xi during B cell stimulation [RNA-seq]

Project description:The inactive X (Xi) is formed by a process called X-Chromosome Inactivation (XCI), with Xist upregulation, retention of Xist RNA transcripts at the Xi, chromatin re-organization, and transcriptional silencing. Female lymphocytes have ‘dynamic’ XCI maintenance where Xist RNA is transcribed but absent from the Xi in naïve lymphocytes and re-localizes after in-vitro activation. How ‘dynamic’ XCI impacts Xi dosage and nuclear organization, or where Xist RNA interacts with the Xi is unknown. Here we find maintenance of Xi dosage and global structure despite the absence of Xist RNA in naïve B-cells. However, we identified 104 escape genes and observe a gain of de-novo TADs on the Xi. Stimulation-dependent Xi remodeling co-occurs with Xist RNA re-accumulation at the Xi, and loss of Xist increases TAD remodeling and decompacts the Xi in both naïve and stimulated B-cells. Altogether, these results reveal B-cell specific Xi plasticity which could underlie female-specific mechanisms in lymphocytes.

2024-12-31 | GSE208393 | GEO

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

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