Allelic silencing analysis for A-repeat and m6A region in mouse Xist
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE142270 | GEO | 2020/02/01
REPOSITORIES: GEO
Similar Datasets
Project description:Allelic silencing analysis for A-repeat and m6A region in mouse Xist
| PRJNA596451 | ENA
Project description:The noncoding Xist RNA could mediate chromosome inaccessiblity, especially for the pre-open chromatin regions (enhancer, promoter, CTCF). However, Xist lacking the B-repeats loss the ability of closing the chromatin accessibility. ATAC-seq is consistent with the observation by ATAC-see. XR-PID denotes the Xist RNA polycomb interacting domain, including the entire B-repeats and part of C repeats.
2017-12-08 | GSE102848 | GEO
Project description:By m6A-seq, we examined the m6A pattern on Xist and Xist_Del_A-repeat, which immediately after the A-repeat region. A-repeat deletion abolished the m6A methylation downstream the A-repeat but not the m6A peak located in Xist exon VII.
2020-02-01 | GSE142271 | GEO
Project description:The Polycomb repressive complexes PRC1 and PRC2 play a key role in chromosome silencing by Xist RNA. Previously we have shown that initation of Polycomb recruitment is mediated by the PCGF3/5-PRC1 complex, which catalyses chromosome-wide H2A ubiquitylation (H2AK119u1), signalling recruitment of other PRC1 complexes, and PRC2. However, the molecular basis for PCGF3/5-PRC1 recruitment by Xist RNA remains unknown. Here we define the Xist RNA Polycomb Interaction Domain (XR-PID), a 600 nt element encompassing the Xist B-repeat element. XR-PID is required for Polycomb recruitment by Xist RNA, Xist-mediated chromosome silencing. We identify the RNA-binding protein hnRNPK as the principal XR-PID binding factor required to recruit PCGF3/5-PRC1. Accordingly, synthetically tethering hnRNPK to Xist RNA lacking the B-repeat is sufficient for Xist-dependent Polycomb recruitment. Our findings resolve the molecular mechanism for Polycomb recruitment by Xist RNA, providing key insights into chromatin modification by non-coding RNA.
2017-12-08 | GSE99924 | GEO
Project description:XIST is a long non-coding RNA (lncRNA) that mediates transcriptional silencing of X chromosome genes. Here we show that XIST is highly methylated with at least 78 N6-methyladenosine (m6A) residues, a reversible base modification whose function in lncRNAs is unknown. We show that m6A formation in XIST, as well as cellular mRNAs, is mediated by RBM15 and its paralog RBM15B, which bind the m6A-methylation complex and recruit it to specific sites in RNA. This results in methylation of adenosines in adjacent m6A consensus motifs. Furthermore, knockdown of RBM15 and RBM15B, or knockdown of the m6A methyltransferase METTL3 impairs XIST-mediated gene silencing. A systematic comparison of m6A-binding proteins shows that YTHDC1 preferentially recognizes m6A in XIST and is required for XIST function. Additionally, artificial tethering of YTHDC1 to XIST rescues XIST-mediated silencing upon loss of m6A. These data reveal a pathway of m6A formation and recognition required for XIST-mediated transcriptional repression. Three to four biological HEK293T replicates were used to perform iCLIP of endogenous YTH proteins, RBM15, and RBM15B. Crosslinking induced truncations were identified using CIMS-CITS pipeline.
2016-09-07 | E-GEOD-78030 | biostudies-arrayexpress
Project description:Xist RNA, the master regulator of X chromosome inactivation, acts in cis to induce chromosome silencing through the stepwise recruitment of factors that modify underlying chromatin structure. Whilst considerable progress has been made towards defining key silencing factors and the elements to which they bind, their relative contribution to silencing different genes, and their relationship with one another is poorly understood. Here we describe a systematic analysis of Xist-mediated allelic silencing in ES cell-based models. We show that Spen, recruited through the Xist A-repeat, plays a central role, being critical for silencing of all except a subset of low expressed genes. Polycomb, recruited through the Xist B/C-repeat, also plays a key role, favouring silencing of genes with pre-existing H3K27me3 chromatin. LBR and the Rbm15-Mettl3/14 m6A-methyltransferase complex, previously proposed to have a central role, make at most a minor contribution to gene silencing. We integrate our findings in a comprehensive model for Xist-mediated chromosome silencing.
2019-06-17 | GSE119602 | GEO
Project description:The long non-coding RNA Xist exploits numerous effector proteins to gradually induce gene silencing across the X chromosome. Here, we show that formation of the inactive X (Xi)-compartment is induced by ~50 locally confined granules, where two Xist RNA molecules nucleate supra-molecular complexes (SMCs) of interacting proteins. Xist-SMCs are dynamic structures that concentrate rapidly recycling proteins on the X by increasing their binding affinity, thereby facilitating their access to the entire chromosome. We find that gene silencing originates at Xist-SMCs and propagates across the entire X chromosome over time. The propagation of silencing is achieved by Polycomb-mediated coalescence of chromatin regions and aggregation of the critical silencing enzyme SPEN, via its intrinsically disordered domains. Our observations suggest a new model for X Chromosome Inactivation, whereby Xist RNA triggers macromolecular crowding of heterochromatinizing proteins at distinct sites to ultimately increase their occupancy throughout the X chromosome . This mechanism enables deterministic gene silencing across an entire chromosome without the need for Xist ribonucleoprotein complex-chromatin interactions at each target gene. Our findings uncover a spatial organization mechanism by which few RNA molecules can regulate a broad nuclear compartment through the recruitment and local concentration of dynamic effector proteins, and provide a quantitative framework for studying such compartments.
2021-10-27 | GSE162011 | GEO
Project description:The long non-coding RNA Xist exploits numerous effector proteins to gradually induce gene silencing across the X chromosome. Here, we show that formation of the inactive X (Xi)-compartment is induced by ~50 locally confined granules, where two Xist RNA molecules nucleate supra-molecular complexes (SMCs) of interacting proteins. Xist-SMCs are dynamic structures that concentrate rapidly recycling proteins on the X by increasing their binding affinity, thereby facilitating their access to the entire chromosome. We find that gene silencing originates at Xist-SMCs and propagates across the entire X chromosome over time. The propagation of silencing is achieved by Polycomb-mediated coalescence of chromatin regions and aggregation of the critical silencing enzyme SPEN, via its intrinsically disordered domains. Our observations suggest a new model for X Chromosome Inactivation, whereby Xist RNA triggers macromolecular crowding of heterochromatinizing proteins at distinct sites to ultimately increase their occupancy throughout the X chromosome. This mechanism enables deterministic gene silencing across an entire chromosome without the need for Xist ribonucleoprotein complex-chromatin interactions at each target gene. Our findings uncover a spatial organization mechanism by which few RNA molecules can regulate a broad nuclear compartment through the recruitment and local concentration of dynamic effector proteins, and provide a quantitative framework for studying such compartments.
2021-10-27 | GSE181235 | GEO
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
Project description:Calibrated ChIP-seq was employed to quantitatively address the questions of how and where Xist recruits polycomb modifications (H2AK119ub and H3K27me3) to the inactive chromosome. 'Dox' samples were performed after 24 hours of induced Xist expression. Suz12 is the core enzymatic component of PRC2 while Pcgf3/5 are non-canonical PRC1 components which initiate the polycomb cascade in Xist-mediated chromosome inactivation. Xist PID region, encompassing the B-repeat and part of C-repeat, was characterized to bind hnRNPK directly, then recruit the Pcgf3/5. Notably, Suz12 KO does not affect Xist-dependent H2AK119ub deposition too much in a 24hour Xist induction.
2019-06-17 | GSE119599 | GEO