R loops regulate promoter-proximal chromatin architecture and cellular differentiation
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE67584 | GEO | 2015/09/30
SECONDARY ACCESSION(S): PRJNA280332
REPOSITORIES: GEO
Similar Datasets
Project description:Numerous chromatin-remodeling factors are regulated by interactions with RNA, although the contexts and functions of RNA binding are poorly understood. Here we show that R loops, RNA-DNA hybrids consisting of nascent transcripts hybridized to template DNA, modulate the binding of two key chromatin-regulatory complexes, Tip60-p400 and polycomb repressive complex 2 (PRC2) in mouse embryonic stem cells (ESCs). Like PRC2, the Tip60-p400 histone acetyltransferase complex binds to nascent transcripts; however, transcription promotes chromatin binding of Tip60-p400 but not PRC2. Interestingly, we observed higher Tip60-p400 and lower PRC2 levels at genes marked by promoter-proximal R loops. Furthermore, disruption of R loops broadly decreased Tip60-p400 occupancy and increased PRC2 occupancy genome wide. In agreement with these alterations, ESCs partially depleted of R loops exhibited impaired differentiation. These results show that R loops act both positively and negatively in modulating the recruitment of key pluripotency regulators.
| S-EPMC4677832 | biostudies-literature
Project description:R loops regulate promoter-proximal chromatin architecture and cellular differentiation
| PRJNA280332 | ENA
Project description:Numerous chromatin-remodelling factors are regulated by interactions with RNA. However, the contexts in which chromatin-remodelling factors encounter various RNA species, as well as the molecular functions of RNA binding, are poorly understood. Here we show that R-loops, RNA:DNA hybrids consisting of nascent transcripts hybridized to template DNA strands, facilitate embryonic stem cell (ESC) differentiation by modulating the binding of two key chromatin-remodelling enzymes near gene promoters. As previously shown for polycomb repressive complex 2 (PRC2)1-5, we find that the Tip60-p400 histone acetyltransferase and nucleosome-remodelling complex binds in cis to nascent transcripts. However, whereas chromatin binding by PRC2 is broadly inhibited by transcription6, transcription is necessary for maximal Tip60-p400 binding at most target loci. Given that nascent transcripts expressed from GC-rich promoters frequently form R-loops7, we mapped the genomic locations of R-loops in mouse ESCs, observing higher average Tip60-p400 levels and lower average PRC2 levels at genes with R-loops near their transcription start sites (TSSs). Disruption of R-loops by overexpression of RNaseH1 broadly reduced Tip60-p400 and increased PRC2 enrichment, demonstrating R-loops exert both positive and negative effects on chromatin association by regulatory factors. Consistent with these findings, RNaseH1 overexpression results in widespread changes in gene expression and inhibits ESC differentiation, allowing undifferentiated cells to persist for at least two weeks after differentiation is induced. These results define a novel mechanism by which promoter-proximal R-loops modulate chromatin structure to facilitate changes in cellular identity.
2015-09-30 | GSE67582 | GEO
Project description:Numerous chromatin-remodelling factors are regulated by interactions with RNA. However, the contexts in which chromatin-remodelling factors encounter various RNA species, as well as the molecular functions of RNA binding, are poorly understood. Here we show that R-loops, RNA:DNA hybrids consisting of nascent transcripts hybridized to template DNA strands, facilitate embryonic stem cell (ESC) differentiation by modulating the binding of two key chromatin-remodelling enzymes near gene promoters. As previously shown for polycomb repressive complex 2 (PRC2)1-5, we find that the Tip60-p400 histone acetyltransferase and nucleosome-remodelling complex binds in cis to nascent transcripts. However, whereas chromatin binding by PRC2 is broadly inhibited by transcription6, transcription is necessary for maximal Tip60-p400 binding at most target loci. Given that nascent transcripts expressed from GC-rich promoters frequently form R-loops7, we mapped the genomic locations of R-loops in mouse ESCs, observing higher average Tip60-p400 levels and lower average PRC2 levels at genes with R-loops near their transcription start sites (TSSs). Disruption of R-loops by overexpression of RNaseH1 broadly reduced Tip60-p400 and increased PRC2 enrichment, demonstrating R-loops exert both positive and negative effects on chromatin association by regulatory factors. Consistent with these findings, RNaseH1 overexpression results in widespread changes in gene expression and inhibits ESC differentiation, allowing undifferentiated cells to persist for at least two weeks after differentiation is induced. These results define a novel mechanism by which promoter-proximal R-loops modulate chromatin structure to facilitate changes in cellular identity.
2015-09-30 | GSE67581 | GEO
Project description:Numerous chromatin-remodelling factors are regulated by interactions with RNA. However, the contexts in which chromatin-remodelling factors encounter various RNA species, as well as the molecular functions of RNA binding, are poorly understood. Here we show that R-loops, RNA:DNA hybrids consisting of nascent transcripts hybridized to template DNA strands, facilitate embryonic stem cell (ESC) differentiation by modulating the binding of two key chromatin-remodelling enzymes near gene promoters. As previously shown for polycomb repressive complex 2 (PRC2)1-5, we find that the Tip60-p400 histone acetyltransferase and nucleosome-remodelling complex binds in cis to nascent transcripts. However, whereas chromatin binding by PRC2 is broadly inhibited by transcription6, transcription is necessary for maximal Tip60-p400 binding at most target loci. Given that nascent transcripts expressed from GC-rich promoters frequently form R-loops7, we mapped the genomic locations of R-loops in mouse ESCs, observing higher average Tip60-p400 levels and lower average PRC2 levels at genes with R-loops near their transcription start sites (TSSs). Disruption of R-loops by overexpression of RNaseH1 broadly reduced Tip60-p400 and increased PRC2 enrichment, demonstrating R-loops exert both positive and negative effects on chromatin association by regulatory factors. Consistent with these findings, RNaseH1 overexpression results in widespread changes in gene expression and inhibits ESC differentiation, allowing undifferentiated cells to persist for at least two weeks after differentiation is induced. These results define a novel mechanism by which promoter-proximal R-loops modulate chromatin structure to facilitate changes in cellular identity.
2015-09-30 | GSE67580 | GEO
Project description:Numerous chromatin-remodelling factors are regulated by interactions with RNA. However, the contexts in which chromatin-remodelling factors encounter various RNA species, as well as the molecular functions of RNA binding, are poorly understood. Here we show that R-loops, RNA:DNA hybrids consisting of nascent transcripts hybridized to template DNA strands, facilitate embryonic stem cell (ESC) differentiation by modulating the binding of two key chromatin-remodelling enzymes near gene promoters. As previously shown for polycomb repressive complex 2 (PRC2)1-5, we find that the Tip60-p400 histone acetyltransferase and nucleosome-remodelling complex binds in cis to nascent transcripts. However, whereas chromatin binding by PRC2 is broadly inhibited by transcription6, transcription is necessary for maximal Tip60-p400 binding at most target loci. Given that nascent transcripts expressed from GC-rich promoters frequently form R-loops7, we mapped the genomic locations of R-loops in mouse ESCs, observing higher average Tip60-p400 levels and lower average PRC2 levels at genes with R-loops near their transcription start sites (TSSs). Disruption of R-loops by overexpression of RNaseH1 broadly reduced Tip60-p400 and increased PRC2 enrichment, demonstrating R-loops exert both positive and negative effects on chromatin association by regulatory factors. Consistent with these findings, RNaseH1 overexpression results in widespread changes in gene expression and inhibits ESC differentiation, allowing undifferentiated cells to persist for at least two weeks after differentiation is induced. These results define a novel mechanism by which promoter-proximal R-loops modulate chromatin structure to facilitate changes in cellular identity.
2015-09-30 | GSE67583 | GEO
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2021-12-03 | GSE190057 | GEO
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2013-07-08 | E-GEOD-48571 | biostudies-arrayexpress
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2017-06-25 | GSE84662 | GEO
Project description:The classic model of eukaryotic gene expression requires direct spatial contact between a distal enhancer and a proximal promoter. Recent Chromosome Conformation Capture (3C) studies show that enhancers and promoters are embedded in a complex network of looping interactions. Here we use a polymer model of chromatin fiber to investigate whether, and to what extent, looping interactions between elements in the vicinity of an enhancer-promoter pair can influence their contact frequency. Our equilibrium polymer simulations show that a chromatin loop, formed by elements flanking either an enhancer or a promoter, suppresses enhancer-promoter interactions, working as an insulator. A loop formed by elements located in the region between an enhancer and a promoter, on the contrary, facilitates their interactions. We find that different mechanisms underlie insulation and facilitation; insulation occurs due to steric exclusion by the loop, and is a global effect, while facilitation occurs due to an effective shortening of the enhancer-promoter genomic distance, and is a local effect. Consistently, we find that these effects manifest quite differently for in silico 3C and microscopy. Our results show that looping interactions that do not directly involve an enhancer-promoter pair can nevertheless significantly modulate their interactions. This phenomenon is analogous to allosteric regulation in proteins, where a conformational change triggered by binding of a regulatory molecule to one site affects the state of another site.
| S-EPMC4207457 | biostudies-literature