Coactivator condensation at super-enhancers links phase separation and gene control (RNA-Seq)
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PROVIDER: PRJNA449067 | ENA |
REPOSITORIES: ENA
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Project description:Coactivator condensation at super-enhancers links phase separation and gene control
| PRJNA449064 | ENA
Project description:Coactivator condensation at super-enhancers links phase separation and gene control (ChIP-Seq)
| PRJNA449065 | ENA
Project description:Super-enhancers (SEs) are clusters of enhancers that cooperatively assemble a high density of transcriptional apparatus to drive robust expression of genes with prominent roles in cell identity. We recently proposed that a phase-separated multi-molecular assembly underlies the formation and function of SEs. Here, we demonstrate that the SE-enriched factors BRD4 and MED1 form nuclear puncta that occur at SEs and exhibit properties of liquid-like condensates. Disruption of BRD4 and MED1 puncta by 1,6-hexanediol is accompanied by a loss of BRD4 and MED1 at SEs and a loss of RNAPII from SE-driven genes. We find that the intrinsically disordered regions (IDRs) of BRD4 and MED1 are sufficient to form phase-separated droplets in vitro and the MED1 IDR promotes phase separation in living cells. The MED1 IDR droplets are capable of compartmentalizing BRD4 and other transcriptional machinery in nuclear extracts. These results support the idea that SEs form phase-separated condensates that compartmentalize the transcription apparatus at key genes, provide insights into the role of cofactor IDRs in this process, and offer new insights into mechanisms involved in control of key cell identity genes.
2018-04-07 | GSE112807 | GEO
Project description:Super-enhancers (SEs) are clusters of enhancers that cooperatively assemble a high density of transcriptional apparatus to drive robust expression of genes with prominent roles in cell identity. We recently proposed that a phase-separated multi-molecular assembly underlies the formation and function of SEs. Here, we demonstrate that the SE-enriched factors BRD4 and MED1 form nuclear puncta that occur at SEs and exhibit properties of liquid-like condensates. Disruption of BRD4 and MED1 puncta by 1,6-hexanediol is accompanied by a loss of BRD4 and MED1 at SEs and a loss of RNAPII from SE-driven genes. We find that the intrinsically disordered regions (IDRs) of BRD4 and MED1 are sufficient to form phase-separated droplets in vitro and the MED1 IDR promotes phase separation in living cells. The MED1 IDR droplets are capable of compartmentalizing BRD4 and other transcriptional machinery in nuclear extracts. These results support the idea that SEs form phase-separated condensates that compartmentalize the transcription apparatus at key genes, provide insights into the role of cofactor IDRs in this process, and offer new insights into mechanisms involved in control of key cell identity genes.
2018-04-07 | GSE112806 | GEO
Project description: Not available
| S-EPMC6092193 | biostudies-literature
Project description:This SuperSeries is composed of the SubSeries listed below.
2018-04-07 | GSE112808 | GEO
Project description:The coactivator p300/CBP regulates genes by facilitating the assembly of transcriptional machinery and by acetylating histones and other factors. However, it remains mostly unclear how both functions of p300 are dynamically coordinated during gene control. Here, we showed that p300 appears to orchestrate two functions through the formation of dynamic co-condensates with certain transcription factors (TFs), which is mediated by the interactions between the TF’s trans-activation domain (TAD) and the intrinsically disordered regions (IDRs) of p300. Co-condensation enables spatially defined, all-or-none activation of p300’s catalytic activity, priming the recruitment of other coactivators including Brd4. We further revealed that co-condensation modulates transcriptional initiation rate and burst duration of target genes, underlying nonlinear and cooperative gene regulatory functions. Intriguingly, such modulation is consistent with how p300 shapes transcriptional bursting kinetics globally. Together, complementary lines of evidence suggest a new p300-mediated gene control mechanism, where TF and p300 co-condensation contributes to transcriptional bursting regulation and cooperative gene control.
2022-02-28 | GSE161958 | GEO
Project description:During development, cells make switch-like decisions to activate the expression of new gene programs leading to lineage specification1. The mechanisms underlying these decisive choices remain unclear2. Here we find that Myocardin (MYOCD), a cardiomyocyte and smooth muscle cell-specific transcriptional coactivator3-6, activates lineage-specific gene programs by concentration-dependent and switch-like formation of nuclear condensates. While compartmentalization of the transcriptional machinery by condensates has been associated with gene activation7,8, directly linking the two processes has been a major challenge for the field9,10. By modeling the natural changes in MYOCD concentration during development, coupled with quantitative fluorescence microscopy, single-cell resolution reporter assays, and cellular differentiation assays, we demonstrate that condensate formation is directly linked to transcriptional activation and lineage specification. During cardiomyocyte and smooth muscle cell differentiation, the formation of MYOCD condensates precedes activation of cell identity genes and these condensates are present at sites of cell identity gene transcription. MYOCD condensates form, activate gene expression, and specify cell state at critical concentration thresholds, dependent upon the C-terminal disordered region of MYOCD. Disrupting condensate formation by manipulating the sequence of this region impairs gene activation which can be rescued by replacing this region with condensate-forming disordered regions from functionally unrelated proteins. These results demonstrate that coactivator condensation at critical concentrations enables switch-like changes in gene expression programs crucial for lineage specification.
2024-03-20 | GSE235928 | GEO
Project description:Co-condensation between transcription factor and coactivator p300 modulates transcriptional bursting kinetics
| PRJNA680044 | ENA
Project description:Chromatin regulators have become highly attractive targets for cancer therapy, yet many of these regulators are expressed in a broad range of healthy cells and contribute generally to gene expression. An important conundrum has thus emerged: how can inhibition of a general regulator of gene expression produce selective effects at specific oncogenes? Here we investigate how inhibition of the transcriptional coactivator BRD4 (Bromodomain containing 4) leads to selective inhibition of disease-critical oncogenes in a highly malignant blood cancer, multiple myeloma (MM). We found that BRD4 generally occupies the promoter elements of active genes together with the Mediator coactivator, but remarkably high levels of these two coactivator proteins were associated with a small set of exceptionally large enhancers. These super-enhancers are associated with genes that feature prominently in MM biology, including the MYC oncogene. Treatment of MM tumor cells with the BET-bromodomain inhibitor JQ1 led to preferential loss of BRD4 at super-enhancers and consequent transcription elongation defects that preferentially impact genes with super-enhancers, including the c-MYC oncogene. Super-enhancers were found at key oncogenic drivers in many other tumor cells. Thus, super-enhancers can regulate oncogenic drivers in tumor cells, which in some cells can be preferentially disrupted by BRD4 inhibition, which in turn contributes to the selective transcriptional effects observed at these oncogenes. These observations have implications for the discovery of novel cancer therapeutics directed at components of super-enhancers in diverse tumor types. ChIP-Seq for chromatin regulators and RNA Polymerase II in multiple myeloma, glioblastoma multiforme, and small cell lung cancer
2013-01-02 | E-GEOD-42355 | biostudies-arrayexpress