Chd4 regulates intra-chromatin looping by concealing CTCF sites from B2 SINEs in mESCs
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PROVIDER: PRJNA723205 | ENA |
REPOSITORIES: ENA
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Project description:CTCF plays a critical role in maintaining the three-dimensional (3D) chromatin organization, which is important for gene regulation, as it allows distal regulatory elements to come into proximity with one another. However, the detailed mechanism responsible for establishing and maintaining the recruitment of CTCF remains elusive. Here, we use in situ Hi-C to show that the ATP-dependent chromatin remodeler, Chd4, regulates intra-chromatin looping by controlling chromatin accessibility to conceal aberrant CTCF-binding sites in mouse embryonic stem cells (mESCs). These aberrant CTCF-binding sites are embedded in B2 SINEs and are localized within the interior of chromatin loops. In the absence of Chd4, the aberrant CTCF-binding sites become accessible and improper CTCF recruitment occurs, resulting in disorganization of the 3D chromatin architecture and subsequent disruption of enhancer-promoter interactions and the transcription of the corresponding genes. These results indicate that Chd4 regulates adequate transcription of mESCs by securing the proper 3D chromatin organization.
2022-05-10 | GSE172392 | GEO
Project description:More than 98% of the mammalian genome is noncoding and approximately half is made up of transposable elements. One of the most abundant is the short interspersed nuclear elements (SINE). Among the million copies of SINEs, B2 accounts for ~350,000 in the mouse genome and have garnered special interest because of emerging roles in gene regulation. Our recent work demonstrated that B2 RNA normally binds stress genes to retard transcription elongation. Though epigenetically silenced, B2s become massively upregulated during thermal stress. Specifically, an interaction between B2 RNA and the Polycomb protein, EZH2, results in cleavage of B2 RNA, release of B2 RNA from RNA Polymerase II, and activation of the stress genes. Although an established RNA-binding protein and histone methyltransferase, EZH2 is not known to be a nuclease. Here, we provide evidence for the surprising conclusion that B2 is a self-cleaving RNA. Contact with EZH2 accelerates cleavage rate by >100-fold, suggesting that EZH2 may assist cleavage as an RNA chaperone. Modification-interference analysis demonstrate that phosphorothioate changes at A and C nucleotides can substitute for EZH2’s function. B2 mutagenesis indicate that nucleotides around positions 45-55 and 100-101 are critical for cleavage reaction. Finally, we demonstrate that another family of SINEs, the ALU elements produce also a self-cleaving RNA. ALUs are intrinsically more auto-reactive than B2s. We propose that the B2/ALU SINEs are a new class of ribozymes whose activity is accelerated by EZH2.
2020-01-31 | GSE139931 | GEO
Project description:We identified a novel long non-coding RNA Lx8-SINE B2, that is a marker of pluripotency. Depletion of Lx8-SINE B2 impacts embryonic stem cell self-renewal. RNA-seq analysis of Lx8-SINE B2 depletion revealed that a number of glycolytic genes with decreased expression. Mechanistically, we found that the Lx8-SINE B2 activates the glycolysis pathway by binding to Eno1. Collectively, our data suggest that Lx8-SINE B2 maintains the self-renewal of mESCs through glycolysis.
2022-09-19 | GSE182247 | GEO
Project description:Short interspersed nuclear elements (SINEs) are retrotransposons evolutionarily derived from endogenous RNA Polymerase III RNAs. Though SINE elements have undergone exaptation into gene regulatory elements, how transcribed SINE RNA impacts transcriptional and post-transcriptional regulation is largely unknown. This is partly due to a lack of information regarding which of the loci have transcriptional potential. Here, we present an approach (short interspersed nuclear element sequencing, SINE-seq), which selectively profiles RNA Polymerase III-derived SINE RNA, thereby identifying transcriptionally active SINE loci. Applying SINE-seq to monitor murine B2 SINE expression during a gammaherpesvirus infection revealed transcription from 28,270 SINE loci, with ~50% of active SINE elements residing within annotated RNA Polymerase II loci. Furthermore, B2 RNA can form intermolecular RNA-RNA interactions with complementary mRNAs, leading to nuclear retention of the targeted mRNA via a mechanism involving p54nrb. These findings illuminate a pathway for the selective regulation of mRNA export during stress via retrotransposon activation.
2016-10-31 | GSE85518 | GEO
Project description:lncRNAs regulate protein functions via formation of protein-RNA complexes. Previous studies have shown that expression of viral lncRNA, polyadenylated nuclear RNA (PAN RNA) is essential for inducible viral genomic looping and distal gene activation during Kaposi's sarcoma-associated herpesvirus (KSHV) reactivation. Here we show an underlying molecular mechanism and regulation of KSHV latency by a viral lncRNA-CHD4 (chromodomain helicase DNA binding protein 4) interaction. Knock-out of the viral RNA binding protein, ORF57 protein, leads to decreased inducible and static viral genomic loops in latent chromatin and a failure to form RNA polymerase II aggregates in the nucleus during reactivation. We identified that CHD4's enzymatic activity silences viral gene expression by preventing nuclear aggregate formation. Furthermore, integrated genomic and proteomic studies together show that KSHV episomes frequently tether near the host cell centromeres and colocalize with a CHD4 protein complex, ChAHP. KSHV episomes detached from these sites when reactivation is triggered, and PAN RNA binds and inhibits CHD4 DNA binding in vitro. Our studies suggest that CHD4 exhibits strong repressor function by preventing inducible enhancer-promoter looping, and is therefore important for the ability of KSHV to establish and maintain latency in a “poised” state at specific host genomic loci.
2022-03-17 | GSE163098 | GEO
Project description:lncRNAs regulate protein functions via formation of protein-RNA complexes. Previous studies have shown that expression of viral lncRNA, polyadenylated nuclear RNA (PAN RNA) is essential for inducible viral genomic looping and distal gene activation during Kaposi's sarcoma-associated herpesvirus (KSHV) reactivation. Here we show an underlying molecular mechanism and regulation of KSHV latency by a viral lncRNA-CHD4 (chromodomain helicase DNA binding protein 4) interaction. Knock-out of the viral RNA binding protein, ORF57 protein, leads to decreased inducible and static viral genomic loops in latent chromatin and a failure to form RNA polymerase II aggregates in the nucleus during reactivation. We identified that CHD4's enzymatic activity silences viral gene expression by preventing nuclear aggregate formation. Furthermore, integrated genomic and proteomic studies together show that KSHV episomes frequently tether near the host cell centromeres and colocalize with a CHD4 protein complex, ChAHP. KSHV episomes detached from these sites when reactivation is triggered, and PAN RNA binds and inhibits CHD4 DNA binding in vitro. Our studies suggest that CHD4 exhibits strong repressor function by preventing inducible enhancer-promoter looping, and is therefore important for the ability of KSHV to establish and maintain latency in a “poised” state at specific host genomic loci.
2022-03-17 | GSE163694 | GEO
Project description:Glioblastomas (GBM) harbor subpopulations of therapy-resistant tumor initiating cells (TICs) that are self-renewing and multipotent. To understand the regulation of the TIC state, we performed an image-based screen for genes regulating GBM TIC maintenance and identified ZFHX4, a 397-kDa transcription factor. ZFHX4 is required to maintain TIC-associated phenotypes in vitro, suggesting that ZFHX4 regulates TIC differentiation, and its suppression increases glioma-free survival in intracranial xenografts. ZFHX4 interacts with CHD4, a core member of the NuRD (nucleosome remodeling and deacetylase) complex. ZFHX4 and CHD4 bind to overlapping sets of genomic loci and control similar gene expression programs. Using expression data derived from GBM patients, we demonstrate ZFHX4 is a master regulator of CHD4-mediated gene expression. These observations define ZFHX4 as a regulatory factor that links the chromatin remodeling NuRD complex and the GBM TIC state. Examination of binding of ZFHX4 and CHD4 across the human genome, using the 0308 tumor initiating cell line. Two replicates for each protein, compared to whole cell extract inputs.
2014-01-16 | E-GEOD-52419 | biostudies-arrayexpress
Project description:ZFHX4 and CHD4 suppression independently shift tumor initiating cells out of a stem like state and toward a differentiated morphology. After gene suppression via transduction of a lentivirally mediated shRNA construct, RNA was extracted 3 and 5 days later and was hybridized on Affymetrix microarrays. Total RNA was extracted 3 and 5 days after shRNA transduction of 0308 TICs, for 3 (for CHD4) or 5 (ZFHX4) independent experiments. Complementary RNA synthesis and hybridization/scanning of U133 plus 2.0 microarrays using GeneChip products (Affymetrix) was done as described in the GeneChip manual.
2014-01-16 | E-GEOD-52363 | biostudies-arrayexpress
Project description:Our study reveal that Chd4 is essential for stemness maintenance of ESCs. As Chd4 deficient ESCs show attentuated self-renewal ability and induced differentiation marker gene expression. To confirm the effect of Chd4 on the transcriptome profile of ESCs, we performed microarray analyses for Chd4 deficient ESCs.
2017-05-01 | GSE89675 | GEO
Project description:Bacillus subtilis B2 strain:B2 Genome sequencing
| PRJNA196566 | ENA