Lola-I is a promoter pioneer factor that establishes de novo Pol II pausing during development [ATAC-seq]
Ontology highlight
ABSTRACT: While enhancers are often regulated at the level of accessibility by pioneer factors, promoters tend to be constitutively accessible and poised for activation by paused Pol II — thus are often not considered as sites of developmental regulation. Here we show that the accessibility of promoters and the acquisition of paused Pol II can also be subject to developmental regulation by pioneer factors. We show that Lola-I, a Drosophila zinc finger transcription factor, is ubiquitously expressed at the end of embryogenesis and causes its target promoters to become accessible and acquire paused Pol II throughout the embryo. This promoter transition is required but not sufficient for tissue-specific target gene expression. Lola-I mediates this function by binding to the edges of the promoter nucleosomes, which leads to their depletion, similar to the action of pioneer factors at enhancers. These results uncover a level of regulation for promoters that is normally found at enhancers, providing further evidence that promoters and enhancers display unexpectedly similar characteristics.
Project description:While enhancers are often regulated at the level of accessibility by pioneer factors, promoters tend to be constitutively accessible and poised for activation by paused Pol II — thus are often not considered as sites of developmental regulation. Here we show that the accessibility of promoters and the acquisition of paused Pol II can also be subject to developmental regulation by pioneer factors. We show that Lola-I, a Drosophila zinc finger transcription factor, is ubiquitously expressed at the end of embryogenesis and causes its target promoters to become accessible and acquire paused Pol II throughout the embryo. This promoter transition is required but not sufficient for tissue-specific target gene expression. Lola-I mediates this function by binding to the edges of the promoter nucleosomes, which leads to their depletion, similar to the action of pioneer factors at enhancers. These results uncover a level of regulation for promoters that is normally found at enhancers, providing further evidence that promoters and enhancers display unexpectedly similar characteristics.
Project description:While enhancers are often regulated at the level of accessibility by pioneer factors, promoters tend to be constitutively accessible and poised for activation by paused Pol II — thus are often not considered as sites of developmental regulation. Here we show that the accessibility of promoters and the acquisition of paused Pol II can also be subject to developmental regulation by pioneer factors. We show that Lola-I, a Drosophila zinc finger transcription factor, is ubiquitously expressed at the end of embryogenesis and causes its target promoters to become accessible and acquire paused Pol II throughout the embryo. This promoter transition is required but not sufficient for tissue-specific target gene expression. Lola-I mediates this function by binding to the edges of the promoter nucleosomes, which leads to their depletion, similar to the action of pioneer factors at enhancers. These results uncover a level of regulation for promoters that is normally found at enhancers, providing further evidence that promoters and enhancers display unexpectedly similar characteristics.
Project description:While enhancers are often regulated at the level of accessibility by pioneer factors, promoters tend to be constitutively accessible and poised for activation by paused Pol II — thus are often not considered as sites of developmental regulation. Here we show that the accessibility of promoters and the acquisition of paused Pol II can also be subject to developmental regulation by pioneer factors. We show that Lola-I, a Drosophila zinc finger transcription factor, is ubiquitously expressed at the end of embryogenesis and causes its target promoters to become accessible and acquire paused Pol II throughout the embryo. This promoter transition is required but not sufficient for tissue-specific target gene expression. Lola-I mediates this function by binding to the edges of the promoter nucleosomes, which leads to their depletion, similar to the action of pioneer factors at enhancers. These results uncover a level of regulation for promoters that is normally found at enhancers, providing further evidence that promoters and enhancers display unexpectedly similar characteristics.
Project description:While enhancers are often regulated at the level of accessibility by pioneer factors, promoters tend to be constitutively accessible and poised for activation by paused Pol II — thus are often not considered as sites of developmental regulation. Here we show that the accessibility of promoters and the acquisition of paused Pol II can also be subject to developmental regulation by pioneer factors. We show that Lola-I, a Drosophila zinc finger transcription factor, is ubiquitously expressed at the end of embryogenesis and causes its target promoters to become accessible and acquire paused Pol II throughout the embryo. This promoter transition is required but not sufficient for tissue-specific target gene expression. Lola-I mediates this function by binding to the edges of the promoter nucleosomes, which leads to their depletion, similar to the action of pioneer factors at enhancers. These results uncover a level of regulation for promoters that is normally found at enhancers, providing further evidence that promoters and enhancers display unexpectedly similar characteristics.
Project description:While enhancers are often regulated at the level of accessibility by pioneer factors, promoters tend to be constitutively accessible and poised for activation by paused Pol II — thus are often not considered as sites of developmental regulation. Here we show that the accessibility of promoters and the acquisition of paused Pol II can also be subject to developmental regulation by pioneer factors. We show that Lola-I, a Drosophila zinc finger transcription factor, is ubiquitously expressed at the end of embryogenesis and causes its target promoters to become accessible and acquire paused Pol II throughout the embryo. This promoter transition is required but not sufficient for tissue-specific target gene expression. Lola-I mediates this function by binding to the edges of the promoter nucleosomes, which leads to their depletion, similar to the action of pioneer factors at enhancers. These results uncover a level of regulation for promoters that is normally found at enhancers, providing further evidence that promoters and enhancers display unexpectedly similar characteristics.
Project description:While enhancers are often regulated at the level of accessibility by pioneer factors, promoters tend to be constitutively accessible and poised for activation by paused Pol II — thus are often not considered as sites of developmental regulation. Here we show that the accessibility of promoters and the acquisition of paused Pol II can also be subject to developmental regulation by pioneer factors. We show that Lola-I, a Drosophila zinc finger transcription factor, is ubiquitously expressed at the end of embryogenesis and causes its target promoters to become accessible and acquire paused Pol II throughout the embryo. This promoter transition is required but not sufficient for tissue-specific target gene expression. Lola-I mediates this function by binding to the edges of the promoter nucleosomes, which leads to their depletion, similar to the action of pioneer factors at enhancers. These results uncover a level of regulation for promoters that is normally found at enhancers, providing further evidence that promoters and enhancers display unexpectedly similar characteristics.
Project description:Gene expression in metazoans is regulated by RNA Polymerase II (Pol II) promoter-proximal pausing and its release. Previously, we identified that Pol II-associated factor 1 (PAF1) modulates the release of paused Pol II into productive elongation. Here, we find that PAF1 occupies transcriptional enhancers and restrains hyperactivation of a subset of these enhancers. Enhancer activation as the result of Paf1 loss releases Pol II from paused promoters of nearby PAF1 target genes. Knockout of PAF1-regulated enhancers attenuates the release of paused Pol II on PAF1 target genes without major interference in the establishment of pausing at their cognate promoters. Thus, a subset of enhancers can primarily modulate gene expression by controlling the release of paused Pol II in a PAF1-dependent manner.
Project description:Transcription machinery progression is governed by multitasking regulators including SPT5, an evolutionarily conserved factor implicated in virtually all transcriptional steps from enhancer activation to termination. Yet its mechanistic understanding in human cells remains incomplete. Here we utilize rapid degradation system and reveal crucial function of SPT5 in maintaining cellular and chromatin Pol II levels. Rapid SPT5 depletion causes a pronounced reduction of paused Pol II at promoters and enhancers, distinct from NELF degradation resulting in short-distance paused Pol II redistribution. Most of genes exhibit down- but not upregulation, accompanied by greatly impaired transcription activation and altered chromatin landscape at enhancers, and severe Pol II processivity defects at gene bodies. Phosphorylation of KOWx-4/5- linker potentiates pause release and is antagonized by Integrator-PP2A (INTAC) targeting SPT5 and Pol II. Our findings position SPT5 as an essential positive regulator of global transcription by controlling cellular Pol II levels, enhancer activation and landscape, paused Pol II stability, elongation processivity and termination in human.
Project description:Transcription machinery progression is governed by multitasking regulators including SPT5, an evolutionarily conserved factor implicated in virtually all transcriptional steps from enhancer activation to termination. Yet its mechanistic understanding in human cells remains incomplete. Here we utilize rapid degradation system and reveal crucial function of SPT5 in maintaining cellular and chromatin Pol II levels. Rapid SPT5 depletion causes a pronounced reduction of paused Pol II at promoters and enhancers, distinct from NELF degradation resulting in short-distance paused Pol II redistribution. Most of genes exhibit down- but not upregulation, accompanied by greatly impaired transcription activation and altered chromatin landscape at enhancers, and severe Pol II processivity defects at gene bodies. Phosphorylation of KOWx-4/5- linker potentiates pause release and is antagonized by Integrator-PP2A (INTAC) targeting SPT5 and Pol II. Our findings position SPT5 as an essential positive regulator of global transcription by controlling cellular Pol II levels, enhancer activation and landscape, paused Pol II stability, elongation processivity and termination in human.
Project description:Transcription machinery progression is governed by multitasking regulators including SPT5, an evolutionarily conserved factor implicated in virtually all transcriptional steps from enhancer activation to termination. Yet its mechanistic understanding in human cells remains incomplete. Here we utilize rapid degradation system and reveal crucial function of SPT5 in maintaining cellular and chromatin Pol II levels. Rapid SPT5 depletion causes a pronounced reduction of paused Pol II at promoters and enhancers, distinct from NELF degradation resulting in short-distance paused Pol II redistribution. Most of genes exhibit down- but not upregulation, accompanied by greatly impaired transcription activation and altered chromatin landscape at enhancers, and severe Pol II processivity defects at gene bodies. Phosphorylation of KOWx-4/5- linker potentiates pause release and is antagonized by Integrator-PP2A (INTAC) targeting SPT5 and Pol II. Our findings position SPT5 as an essential positive regulator of global transcription by controlling cellular Pol II levels, enhancer activation and landscape, paused Pol II stability, elongation processivity and termination in human.