Super-enhancers require enhancers and facilitators to fully activate gene expression [RNA-seq]
Ontology highlight
ABSTRACT: Super-enhancers are compound regulatory elements which control expression of key cell-identity genes. They recruit high levels of tissue-specific transcription factors, co-activators such as the mediator complex, and they contact their target gene promoters with high frequency. Most super-enhancers contain multiple constituent regulatory elements, but it is unclear whether these elements have distinct roles in activating expression of their cognate genes. Here, through comprehensively rebuilding the endogenous α-globin super-enhancer, we show that super-enhancers comprise bioinformatically equivalent but functionally distinct element types: classical enhancers and facilitator elements. Facilitators have no intrinsic enhancer activity, yet in their absence, classical enhancers are unable to fully up-regulate their target genes. Without facilitators, classical enhancers exhibit reduced mediator recruitment, enhancer RNA transcription and enhancer-promoter interactions. Facilitators are interchangeable, but display functional hierarchy based on their position within a super-enhancer. Facilitators thus play an important role in potentiating super-enhancer activity and ensuring robust activation of target genes.
Project description:Super-enhancers are compound regulatory elements which control expression of key cell-identity genes. They recruit high levels of tissue-specific transcription factors, co-activators such as the mediator complex, and they contact their target gene promoters with high frequency. Most super-enhancers contain multiple constituent regulatory elements, but it is unclear whether these elements have distinct roles in activating expression of their cognate genes. Here, through comprehensively rebuilding the endogenous α-globin super-enhancer, we show that super-enhancers comprise bioinformatically equivalent but functionally distinct element types: classical enhancers and facilitator elements. Facilitators have no intrinsic enhancer activity, yet in their absence, classical enhancers are unable to fully up-regulate their target genes. Without facilitators, classical enhancers exhibit reduced mediator recruitment, enhancer RNA transcription and enhancer-promoter interactions. Facilitators are interchangeable, but display functional hierarchy based on their position within a super-enhancer. Facilitators thus play an important role in potentiating super-enhancer activity and ensuring robust activation of target genes.
Project description:Super-enhancers are compound regulatory elements which control expression of key cell-identity genes. They recruit high levels of tissue-specific transcription factors, co-activators such as the mediator complex, and they contact their target gene promoters with high frequency. Most super-enhancers contain multiple constituent regulatory elements, but it is unclear whether these elements have distinct roles in activating expression of their cognate genes. Here, through comprehensively rebuilding the endogenous α-globin super-enhancer, we show that super-enhancers comprise bioinformatically equivalent but functionally distinct element types: classical enhancers and facilitator elements. Facilitators have no intrinsic enhancer activity, yet in their absence, classical enhancers are unable to fully up-regulate their target genes. Without facilitators, classical enhancers exhibit reduced mediator recruitment, enhancer RNA transcription and enhancer-promoter interactions. Facilitators are interchangeable, but display functional hierarchy based on their position within a super-enhancer. Facilitators thus play an important role in potentiating super-enhancer activity and ensuring robust activation of target genes.
Project description:Super-enhancers are compound regulatory elements which control expression of key cell-identity genes. They recruit high levels of tissue-specific transcription factors, co-activators such as the mediator complex, and they contact their target gene promoters with high frequency. Most super-enhancers contain multiple constituent regulatory elements, but it is unclear whether these elements have distinct roles in activating expression of their cognate genes. Here, through comprehensively rebuilding the endogenous α-globin super-enhancer, we show that super-enhancers comprise bioinformatically equivalent but functionally distinct element types: classical enhancers and facilitator elements. Facilitators have no intrinsic enhancer activity, yet in their absence, classical enhancers are unable to fully up-regulate their target genes. Without facilitators, classical enhancers exhibit reduced mediator recruitment, enhancer RNA transcription and enhancer-promoter interactions. Facilitators are interchangeable, but display functional hierarchy based on their position within a super-enhancer. Facilitators thus play an important role in potentiating super-enhancer activity and ensuring robust activation of target genes.
Project description:The master transcription factors Oct4, Sox2 and Nanog bind enhancer elements and recruit the Mediator co-activator to activate much of the gene expression program of embryonic stem cells (ESCs). We report here that the ESC master transcription factors and Mediator form “super-enhancers” at most genes known to control the pluripotent state, including those encoding the master transcription factors themselves. These super-enhancers consist of extraordinarily large genomic domains occupied by exceptional amounts of Oct4, Sox2, Nanog, Klf4, Esrrb and Mediator. Super-enhancers stimulate considerably higher transcription than typical enhancers in vivo and in reporter vectors. Reduced levels of Oct4 or Mediator cause preferential loss of expression of super-enhancer-associated genes relative to other genes, suggesting how changes in gene expression programs might be accomplished during development. In other more differentiated cells, super-enhancers containing cell-type-specific master transcription factors are also found at genes that define cell identity. These results implicate super-enhancers in the control of mammalian cell identity and differentiation. ChIP-Seq and controls associated with Super-Enhancers in murine cell types
Project description:The master transcription factors Oct4, Sox2 and Nanog bind enhancer elements and recruit the Mediator co-activator to activate much of the gene expression program of embryonic stem cells (ESCs). We report here that these ESC master transcription factors and Mediator form M-bM-^@M-^\super-enhancersM-bM-^@M-^] at most genes that are known to control the pluripotent state, including those encoding the master transcription factors themselves. These super-enhancers consist of extraordinarily large genomic domains occupied by exceptional amounts of Oct4 and Mediator. Super-enhancers stimulate considerably higher transcription than typical enhancers in reporter vectors. ESC differentiation causes preferential loss of expression of super-enhancer -associated genes. Super-enhancers are also found at key cell identity genes in differentiated cells. These results implicate super-enhancers in the control of mammalian cell identity and differentiation and suggest that these elements might generally be used to identify genes that control cell-type specific gene expression programs in many mammalian cells. ChIP-Seq and RNA-seq of Med1 in ZHBTc4 ES during treatment with doxycycline. ChIP-Seq data of Med1 in 38B9 pro-B cells.
Project description:The master transcription factors Oct4, Sox2 and Nanog bind enhancer elements and recruit the Mediator co-activator to activate much of the gene expression program of embryonic stem cells (ESCs). We report here that the ESC master transcription factors and Mediator form M-bM-^@M-^\super-enhancersM-bM-^@M-^] at most genes known to control the pluripotent state, including those encoding the master transcription factors themselves. These super-enhancers consist of extraordinarily large genomic domains occupied by exceptional amounts of Oct4, Sox2, Nanog, Klf4, Esrrb and Mediator. Super-enhancers stimulate considerably higher transcription than typical enhancers in vivo and in reporter vectors. Reduced levels of Oct4 or Mediator cause preferential loss of expression of super-enhancer-associated genes relative to other genes, suggesting how changes in gene expression programs might be accomplished during development. In other more differentiated cells, super-enhancers containing cell-type-specific master transcription factors are also found at genes that define cell identity. These results implicate super-enhancers in the control of mammalian cell identity and differentiation. Time-course of gene expression following shRNA knockdown of Oct4 and Med12.