Epigenetic regulation by dynamic RNA G-quadruplex folding and unfolding (CHART-Seq)
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE219080 | GEO | 2024/05/17
REPOSITORIES: GEO
Similar Datasets
Project description:Whether RNA G-quadruplexes (rG4) form extensively in vivo and what roles they play remain actively debated. Among their proposed functions is recognition of Polycomb repressive complex 2 (PRC2), but how the interaction results in epigenetic regulation is not understood. Here we demonstrate that rG4s form dynamically during ES cell differentiation and require ATRX’s helicase function to unwind competing secondary structures. Mutating ATRX causes rG4 depletion on a transcriptome-wide basis and dramatically increases gene expression. We identify and mutate rG4s within Xist RNA and mechanistically separate PRC2’s recruitment versus catalysis. Surprisingly, although rG4s recruit PRC2, unfolding the rG4 structure causes PRC2 hyperactivation, entrapment of PRC2 in the S1 chromosomal compartment, and loss of gene silencing. Thus, we link dynamic rG4 folding and unfolding to PRC2 recruitment, trans-compartmental Xist migration, regulated activation of PRC2, and whole-chromosome gene silencing.
2024-05-17 | GSE219079 | GEO
Project description:Whether RNA G-quadruplexes (rG4) form extensively in vivo and what roles they play remain actively debated. Among their proposed functions is recognition of Polycomb repressive complex 2 (PRC2), but how the interaction results in epigenetic regulation is not understood. Here we demonstrate that rG4s form dynamically during ES cell differentiation and require ATRX’s helicase function to unwind competing secondary structures. Mutating ATRX causes rG4 depletion on a transcriptome-wide basis and dramatically increases gene expression. We identify and mutate rG4s within Xist RNA and mechanistically separate PRC2’s recruitment versus catalysis. Surprisingly, although rG4s recruit PRC2, unfolding the rG4 structure causes PRC2 hyperactivation, entrapment of PRC2 in the S1 chromosomal compartment, and loss of gene silencing. Thus, we link dynamic rG4 folding and unfolding to PRC2 recruitment, trans-compartmental Xist migration, regulated activation of PRC2, and whole-chromosome gene silencing.
2024-05-17 | GSE219081 | GEO
Project description:Whether RNA G-quadruplexes (rG4) form extensively in vivo and what roles they play remain actively debated. Among their proposed functions is recognition of Polycomb repressive complex 2 (PRC2), but how the interaction results in epigenetic regulation is not understood. Here we demonstrate that rG4s form dynamically during ES cell differentiation and require ATRX’s helicase function to unwind competing secondary structures. Mutating ATRX causes rG4 depletion on a transcriptome-wide basis and dramatically increases gene expression. We identify and mutate rG4s within Xist RNA and mechanistically separate PRC2’s recruitment versus catalysis. Surprisingly, although rG4s recruit PRC2, unfolding the rG4 structure causes PRC2 hyperactivation, entrapment of PRC2 in the S1 chromosomal compartment, and loss of gene silencing. Thus, we link dynamic rG4 folding and unfolding to PRC2 recruitment, trans-compartmental Xist migration, regulated activation of PRC2, and whole-chromosome gene silencing.
2024-05-17 | GSE219082 | GEO
Project description:RNA structures are of crucial importance for biological function and gene regulation. Guanine (G)-rich sequences in RNA can assemble to form RNA G-quadruplex (rG4) structures; specific rG4s have been shown to regulate gene expression, and are associated with human diseases. However, no transcriptome-wide method has been reported to map rG4s, limiting our understanding of the rG4 structure and its relationship with function and regulation. Here we introduce a transcriptome-wide rG4 profiling method, rG4-Seq, in which the rG4-mediated reverse transcriptase stalling is read out by next-generation sequencing at nucleotide resolution. We apply this method to human RNA and report the first global map of rG4 structures for any organism. Our analysis identifies over 3,000 rG4s, and increases to over 11,000 upon addition of a rG4 stabilizing ligand Pyridostatin (PDS). Notably, we discover that besides canonical rG4s, many rG4s are non-canonical with novel structural features such as long-loops, bulges, and 2-quartet. We also find that rG4 formation is associated with its stability, Cytosine (C)-content, and the stability of alternative RNA structures. Our data reveals that rG4s can be found in messenger RNAs (mRNAs) and long intergenic noncoding RNAs (lincRNAs). In mRNAs, rG4s are enriched in untranslated regions, and are significantly correlated with microRNA target sites and polyadenylation signals. Remarkably, we found that majority of our in vitro identified rG4s can change the in silico predicted RNA structure to uncover alternative RNA conformation.. Futhermore, the rG4s that have analogues in many ortholog genes across different species show a preferential association with RNA processing and stability. rG4-seq is a broadly applicable method that enables the RNA G4 structurome and its biological roles to be interrogated and can be readily applied in other organisms on a transcriptome-wide scale. 12 samples, 150 bp single-ended RNA-Seq libraries from cell extracts after performing RTS reaction in different buffers (Li, K and K+PDS rich buffer). Each of the 3 conditions has 4 libraries from independent biological replicates.
2016-08-10 | E-GEOD-77282 | biostudies-arrayexpress
Project description:RNA structures are of crucial importance for biological function and gene regulation. Guanine (G)-rich sequences in RNA can assemble to form RNA G-quadruplex (rG4) structures; specific rG4s have been shown to regulate gene expression, and are associated with human diseases. However, no transcriptome-wide method has been reported to map rG4s, limiting our understanding of the rG4 structure and its relationship with function and regulation. Here we introduce a transcriptome-wide rG4 profiling method, rG4-Seq, in which the rG4-mediated reverse transcriptase stalling is read out by next-generation sequencing at nucleotide resolution. We apply this method to human RNA and report the first global map of rG4 structures for any organism. Our analysis identifies over 3,000 rG4s, and increases to over 11,000 upon addition of a rG4 stabilizing ligand Pyridostatin (PDS). Notably, we discover that besides canonical rG4s, many rG4s are non-canonical with novel structural features such as long-loops, bulges, and 2-quartet. We also find that rG4 formation is associated with its stability, Cytosine (C)-content, and the stability of alternative RNA structures. Our data reveals that rG4s can be found in messenger RNAs (mRNAs) and long intergenic noncoding RNAs (lincRNAs). In mRNAs, rG4s are enriched in untranslated regions, and are significantly correlated with microRNA target sites and polyadenylation signals. Remarkably, we found that majority of our in vitro identified rG4s can change the in silico predicted RNA structure to uncover alternative RNA conformation.. Futhermore, the rG4s that have analogues in many ortholog genes across different species show a preferential association with RNA processing and stability. rG4-seq is a broadly applicable method that enables the RNA G4 structurome and its biological roles to be interrogated and can be readily applied in other organisms on a transcriptome-wide scale.
2016-08-10 | GSE77282 | GEO
Project description:Guanine (G)-rich nucleic acids can fold into G-quadruplex (G4) structures under permissive conditions. Although many RNAs contain sequences that fold into RNA G4s (rG4s) in vitro, their folding and functions in vivo are not well understood. Here, we showed that the folding of putative rG4s in human cells into rG4 structures was dynamically induced by stress. By using high-throughput dimethylsulfate probing, we identified hundreds of endogenous stress-induced rG4s. Our results demonstrated that stress-induced rG4s were enriched in mRNA 3′-untranslated regions and enhanced mRNA stability. Furthermore, stress-induced rG4 folding was readily reversible upon stress removal. In summary, our study revealed the dynamic regulation of rG4 folding in living human cells and suggests suggested that widespread rG4 motifs may have a global regulatory impact on mRNA stability and cellular stress response.
2022-12-15 | GSE200706 | GEO
Project description:G-quadruplexes (rG4s) are recognized as key structures involved in RNA biology and are linked to neurodegenerative disease and cancer. However, detailed knowledge of rG4s and their binding partners is lacking. Here, a systematic, unbiased affinity proteomics approach identified 80 potential high-confidence interactors of the rG4 structure in the 5’UTR of the NRAS oncogene. Using epitope-tagged protein expression, we validated a subset of interactions including DDX3X, DDX5, DDX17, DHX9, DHX36, FXR1, FXR2, GRSF1 and NSUN5. More than half of the identified rG4 interactors were enriched in glycine-arginine (GAR) domains, and for DDX3X and DDX17, we show that the GAR domain is required for rG4 interaction. Transcriptome-wide binding analysis using DDX3X iCLIP revealed a striking association with rG4s in 5’UTRs that was lacking in the GAR-domain mutant. Overall, our work highlights a hitherto unrecognized complexity in rG4 structure-protein interactions that should be considered for the understanding of rG4 function.
2018-04-30 | GSE106476 | GEO
Project description:RNA G-quadruplexes (RG4s) are four-stranded structures known to control mRNA translation of cancer relevant genes. RG4 formation is pervasive in vitro but not in cellulo, indicating the existence of a poorly characterized molecular machinery that remodels RG4s and maintains them unfolded. To help fill this gap in knowledge, we performed a quantitative proteomic screen to identify cytosolic proteins that interact with a canonical RG4 in its folded and unfolded conformation. Our results identified hnRNP H/F as important components of the cytoplasmic machinery modulating RG4s structural integrity, revealed their function in RG4-mediated translation and uncovered the underlying molecular mechanism impacting cellular stress response linked to the outcome of glioblastoma, one of the deadliest types of solid cancer overall.
2020-11-11 | PXD015609 | Pride
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:MALAT1, an abundant lncRNA specifically localized to nuclear speckles, regulates alternative-splicing (AS). The molecular basis of its role in AS remains poorly understood. Here, we report three conserved, thermodynamically stable, parallel RNA-G-quadruplexes (rG4s) present in the 3’ region of MALAT1 which regulates this function. Using rG4 domain specific RNA-pull-down followed by mass-spectrometry, RNA-immuno-precipitation and imaging, we demonstrate the rG4 dependent localization of Nucleolin (NCL) and Nucleophosmin (NPM) to nuclear speckles. Specific G-to-A mutations that abolish rG4 structures, results in the localization loss of both the proteins from speckles. Functionally, disruption of rG4 in MALAT1 phenocopies NCL knockdown resulting in altered pre-mRNA splicing of endogenous genes. These results reveal a central role of rG4s within the 3’ region of MALAT1 orchestrating AS.
2022-02-17 | PXD026386 | Pride