Super-enhancer switching in early mammalian development involves eRNA mediated SWI/SNF recruitment [CUT-RUN]
Ontology highlight
ABSTRACT: The RNA transcribed from enhancer regions, referred to as eRNA, has been suggested to directly activate transcription by helping to recruit transcription factors and co-activators. Although there have been specific examples of eRNA functioning in this way, it is not clear how general this may be. We find the AT-hook of SWI/SNF alone binds preferentially RNA and as part of the esBAF complexes associates with eRNA transcribed from intronic and intergenic regions. SWI/SNF is globally recruited in cis by eRNA to cell-type specific enhancers at two distinct stages in early mammalian development and not at promoters or enhancers that are shared between the two stages. SWI/SNF recruited by eRNA facilitates recruitment and/or activation of MLL3/4, p300/CBP and Mediator co-activators to stage-specific super-enhancers that in the primed embryonic stage activate cell lineage priming related genes. We find a strong connection between ATP-dependent chromatin remodeling and eRNA in cell identity and super-enhancer activation.
Project description:The RNA transcribed from enhancer regions, referred to as eRNA, has been suggested to directly activate transcription by helping to recruit transcription factors and co-activators. Although there have been specific examples of eRNA functioning in this way, it is not clear how general this may be. We find the AT-hook of SWI/SNF alone binds preferentially RNA and as part of the esBAF complexes likely associates with eRNA that are transcribed from intronic and intergenic regions. SWI/SNF is globally recruited in cis by eRNA to cell-type specific enhancers at two distinct stages in early mammalian development and not at promoters or enhancers that are shared between the two stages. SWI/SNF recruited by eRNA facilitates recruitment and/or activation of MLL3/4, p300/CBP and Mediator co-activators to stage-specific super-enhancers that in the primed embryonic stage activate cell lineage priming related genes. We find a strong connection between ATP-dependent chromatin remodeling and eRNA in cell identity and super-enhancer activation.
Project description:The RNA transcribed from enhancer regions, referred to as eRNA, has been suggested to directly activate transcription by helping to recruit transcription factors and co-activators. Although there have been specific examples of eRNA functioning in this way, it is not clear how general this may be. We find the AT-hook of SWI/SNF alone binds preferentially RNA and as part of the esBAF complexes likely associates with eRNA that are transcribed from intronic and intergenic regions. SWI/SNF is globally recruited in cis by eRNA to cell-type specific enhancers at two distinct stages in early mammalian development and not at promoters or enhancers that are shared between the two stages. SWI/SNF recruited by eRNA facilitates recruitment and/or activation of MLL3/4, p300/CBP and Mediator co-activators to stage-specific super-enhancers that in the primed embryonic stage activate cell lineage priming related genes. We find a strong connection between ATP-dependent chromatin remodeling and eRNA in cell identity and super-enhancer activation.
Project description:Genes encoding subunits of SWI/SNF (BAF) chromatin remodeling complexes are collectively altered in over 20% of all human malignancies, but the mechanisms by which these complexes alter chromatin to modulate transcription and control cell fate are poorly understood. Utilizing both loss-of-function and gain-of-function approaches, here we show that SWI/SNF complexes are preferentially targeted to distal enhancers and interact with p300 to regulate transcription via modulation of histone H3 lysine 27 acetylation. We identify a greater requirement for SWI/SNF at typical enhancers than at most super-enhancers and at enhancers in untranscribed regions than in transcribed regions. Our data further demonstrate that SWI/SNF-dependent distal enhancers are essential for controlling expression of genes linked to developmental processes. Our findings thus establish SWI/SNF complexes as regulators of the enhancer landscape and provide insight into the roles of SWI/SNF in cellular fate control.
Project description:Genes encoding subunits of SWI/SNF (BAF) chromatin remodeling complexes are collectively altered in over 20% of all human malignancies, but the mechanisms by which these complexes alter chromatin to modulate transcription and control cell fate are poorly understood. Utilizing both loss-of-function and gain-of-function approaches, here we show that SWI/SNF complexes are preferentially targeted to distal enhancers and interact with p300 to regulate transcription via modulation of histone H3 lysine 27 acetylation. We identify a greater requirement for SWI/SNF at typical enhancers than at most super-enhancers and at enhancers in untranscribed regions than in transcribed regions. Our data further demonstrate that SWI/SNF-dependent distal enhancers are essential for controlling expression of genes linked to developmental processes. Our findings thus establish SWI/SNF complexes as regulators of the enhancer landscape and provide insight into the roles of SWI/SNF in cellular fate control.
Project description:Approximately 75% of the human genome is transcribed, the majority of which does not encode protein. However, most noncoding RNA (ncRNA) is rapidly degraded after transcription, and relatively few have established functions, questioning the significance of this observation. Here we show that esBAF, a SWI/SNF family nucleosome remodeling factor, suppresses transcription of ncRNAs from approximately 57,000 nucleosome-depleted regions (NDRs) throughout the genome of mouse embryonic stem cells (ESCs). We show that esBAF functions both to keep NDRs nucleosome-free and to promote elevated nucleosome occupancy adjacent to NDRs. Reduction of adjacent nucleosome occupancy upon esBAF depletion is strongly correlated with ncRNA expression, suggesting that flanking nucleosomes form a barrier to pervasive transcription. Upon forcing nucleosome occupancy near an NDR using a nucleosome-positioning sequence, we find that esBAF is no longer required to silence transcription. These data reveal a novel role for esBAF in suppressing pervasive transcription from open chromatin regions in ESCs. Examine nucleosome occupancy (MNase-Seq) and transcript production (CapSeq and RNA-Seq) in EGFP KD and Smarca4 KD ESCs
Project description:The current studies show that JMJD1A is phosphorylated at S265 by protein kinase A (PKA), and this is pivotal to activate expression of the b1-adrenergic receptor gene (Adrb1) and downstream targets including Ucp1. Phosphorylation of JMJD1A increases its interaction with the SWI/SNF nucleosome remodeling complex and DNA-bound PPARg. This complex conferred b-adrenergic-induced JMJD1A recruitment to target sites throughout the genome. Phospho-JMJD1A also facilitated long-range chromatin looping to recruit PPARg-bound distal-enhancers, SWI/SNF, and RNA polymerase close to the Adrb1 locus to activate transcription. Mutation of the PKA-phosphorylation site on JMJD1A abolished interactions with SWI/SNF without affecting demethylase activity suggesting the two functions are independent of each other. Our results show that JMJD1A demethylase is also a signal-sensing scaffold that regulates cAMP-responsive transcription via interactions with SWI/SNF and hormone stimulated higher-order chromatin conformational changes. There are 3 samples analyzed. No duplication from each sample. Isoproterenol stimulation at 0hr is used as the relative to fold change in manuscript.
Project description:SMARCB1 (SNF5/INI1/BAF47), a core subunit of the SWI/SNF (BAF) chromatin remodeling complex, is inactivated in nearly all pediatric rhabdoid tumors. These aggressive cancers are among the most genomically stable, suggesting an epigenetic mechanism by which SMARCB1 loss drives transformation. Here, we show that despite indistinguishable mutational landscapes, human RTs show distinct enhancer H3K27ac signatures, which reveal remnants of differentiation programs. We show that SMARCB1 is required for the integrity of SWI/SNF complexes and that its loss alters enhancer targeting markedly impairing SWI/SNF binding to typical enhancers, particularly those required for differentiation, while maintaining SWI/SNF binding at super-enhancers. We show that these retained super-enhancers are essential for rhabdoid tumor survival, including some that are shared across all subtypes, such as SPRY1, and other lineage-specific super-enhancers like SOX2 in brain-derived RTs. Taken together, our findings reveal a novel chromatin-based epigenetic mechanism underlying the tumor suppressive activity of SMARCB1.
Project description:SMARCB1 (SNF5/INI1/BAF47), a core subunit of the SWI/SNF (BAF) chromatin remodeling complex, is inactivated in nearly all pediatric rhabdoid tumors. These aggressive cancers are among the most genomically stable, suggesting an epigenetic mechanism by which SMARCB1 loss drives transformation. Here, we show that despite indistinguishable mutational landscapes, human RTs show distinct enhancer H3K27ac signatures, which reveal remnants of differentiation programs. We show that SMARCB1 is required for the integrity of SWI/SNF complexes and that its loss alters enhancer targeting markedly impairing SWI/SNF binding to typical enhancers, particularly those required for differentiation, while maintaining SWI/SNF binding at super-enhancers. We show that these retained super-enhancers are essential for rhabdoid tumor survival, including some that are shared across all subtypes, such as SPRY1, and other lineage-specific super-enhancers like SOX2 in brain-derived RTs. Taken together, our findings reveal a novel chromatin-based epigenetic mechanism underlying the tumor suppressive activity of SMARCB1.
Project description:SMARCB1 (SNF5/INI1/BAF47), a core subunit of the SWI/SNF (BAF) chromatin remodeling complex, is inactivated in nearly all pediatric rhabdoid tumors. These aggressive cancers are among the most genomically stable, suggesting an epigenetic mechanism by which SMARCB1 loss drives transformation. Here, we show that despite indistinguishable mutational landscapes, human RTs show distinct enhancer H3K27ac signatures, which reveal remnants of differentiation programs. We show that SMARCB1 is required for the integrity of SWI/SNF complexes and that its loss alters enhancer targeting markedly impairing SWI/SNF binding to typical enhancers, particularly those required for differentiation, while maintaining SWI/SNF binding at super-enhancers. We show that these retained super-enhancers are essential for rhabdoid tumor survival, including some that are shared across all subtypes, such as SPRY1, and other lineage-specific super-enhancers like SOX2 in brain-derived RTs. Taken together, our findings reveal a novel chromatin-based epigenetic mechanism underlying the tumor suppressive activity of SMARCB1.
Project description:SMARCB1 (SNF5/INI1/BAF47), a core subunit of the SWI/SNF (BAF) chromatin remodeling complex, is inactivated in nearly all pediatric rhabdoid tumors. These aggressive cancers are among the most genomically stable, suggesting an epigenetic mechanism by which SMARCB1 loss drives transformation. Here, we show that despite indistinguishable mutational landscapes, human RTs show distinct enhancer H3K27ac signatures, which reveal remnants of differentiation programs. We show that SMARCB1 is required for the integrity of SWI/SNF complexes and that its loss alters enhancer targeting markedly impairing SWI/SNF binding to typical enhancers, particularly those required for differentiation, while maintaining SWI/SNF binding at super-enhancers. We show that these retained super-enhancers are essential for rhabdoid tumor survival, including some that are shared across all subtypes, such as SPRY1, and other lineage-specific super-enhancers like SOX2 in brain-derived RTs. Taken together, our findings reveal a novel chromatin-based epigenetic mechanism underlying the tumor suppressive activity of SMARCB1.