Project description:The protein IWS1 (Interacts with SPT6 1) has been implicated in various transcription-associated processes, but whether it has a direct role in RNA polymerase (Pol) II transcription remains unclear. Here, we establish a rapid depletion system for IWS1 in human cells, and use it to elucidate its function in vivo by multi-omics kinetic analysis. We show that IWS1 depletion results in a global decrease of RNA synthesis in vivo that is due to a decrease in Pol II elongation velocity and in vitro biochemical assays reveal that IWS1 directly stimulates Pol II transcription by lowering the nucleosome entry barrier. Further analyses show that H3K36me3 decreases upon IWS1 depletion although the recruitment of the histone methyltransferase SETD2 to chromatin is unaffected. We conclude that IWS1 has a direct role in Pol II transcription and is essential for maintaining normal RNA elongation, which in turn is required for normal chromatin methylation.
Project description:The protein IWS1 (Interacts with SPT6 1) has been implicated in various transcription-associated processes, but whether it has a direct role in RNA polymerase (Pol) II transcription remains unclear. Here, we establish a rapid depletion system for IWS1 in human cells, and use it to elucidate its function in vivo by multi-omics kinetic analysis. We show that IWS1 depletion results in a global decrease of RNA synthesis in vivo that is due to a decrease in Pol II elongation velocity and in vitro biochemical assays reveal that IWS1 directly stimulates Pol II transcription by lowering the nucleosome entry barrier. Further analyses show that H3K36me3 decreases upon IWS1 depletion although the recruitment of the histone methyltransferase SETD2 to chromatin is unaffected. We conclude that IWS1 has a direct role in Pol II transcription and is essential for maintaining normal RNA elongation, which in turn is required for normal chromatin methylation.
Project description:Interacts with SPT6 1 (IWS1) has been implicated in various co-transcriptional processes, yet its direct role in RNA Polymerase (Pol) II transcription in vivo remains elusive. In this study, we utilized a rapid depletion system of IWS1 in human cells, followed by multi-omics analysis and biochemical assays, to elucidate its function. We show that IWS1 depletion results in a global decrease of RNA synthesis, but does not affect the chromatin recruitment of the histone methyltransferase SETD2. In vivo and in vitro analyses of nascent transcription and histone modifications revealed that the observed decrease in methylation is a secondary effect of the transcription defect caused by IWS1 depletion. Whereas these results show that IWS1 is essential for maintaining normal RNA Pol II elongation velocity in vivo, and that it can directly stimulate transcription.
Project description:Interacts with SPT6 1 (IWS1) has been implicated in various co-transcriptional processes, yet its direct role in RNA Polymerase (Pol) II transcription in vivo remains elusive. In this study, we utilized a rapid depletion system of IWS1 in human cells, followed by multi-omics analysis and biochemical assays, to elucidate its function. We show that IWS1 depletion results in a global decrease of RNA synthesis, but does not affect the chromatin recruitment of the histone methyltransferase SETD2. In vivo and in vitro analyses of nascent transcription and histone modifications revealed that the observed decrease in methylation is a secondary effect of the transcription defect caused by IWS1 depletion. Whereas these results show that IWS1 is essential for maintaining normal RNA Pol II elongation velocity in vivo, and that it can directly stimulate transcription.
Project description:Interacts with SPT6 1 (IWS1) has been implicated in various co-transcriptional processes, yet its direct role in RNA Polymerase (Pol) II transcription in vivo remains elusive. In this study, we utilized a rapid depletion system of IWS1 in human cells, followed by multi-omics analysis and biochemical assays, to elucidate its function. We show that IWS1 depletion results in a global decrease of RNA synthesis, but does not affect the chromatin recruitment of the histone methyltransferase SETD2. In vivo and in vitro analyses of nascent transcription and histone modifications revealed that the observed decrease in methylation is a secondary effect of the transcription defect caused by IWS1 depletion. Whereas these results show that IWS1 is essential for maintaining normal RNA Pol II elongation velocity in vivo, and that it can directly stimulate transcription.
Project description:RNA polymerase II (Pol II) elongation is a critical step in gene expression. Here we find that NDF, which was identified as a bilaterian nucleosome-destabilizing factor, is also a Pol II transcription factor that stimulates elongation with plain DNA templates in the absence of nucleosomes. NDF binds directly to Pol II and enhances elongation by a different mechanism than does transcription factor TFIIS. Moreover, yeast Pdp3, which is related to NDF, binds to Pol II and stimulates elongation. Thus, NDF is a Pol II-binding transcription elongation factor that is localized over gene bodies and is conserved from yeast to humans.
Project description:To reveal the influence of TND-interacting motifs (TIMs), which bind TFIIS N-terminal domains (TNDs), we prepared KELLY cells expressing either wild-type IWS1-FLAG or IWS1-FLAG containing disruptive mutations in the unstructured TIM3 region. Following lentiviral transduction of either WT or M3 IWS1-FLAG, we prepared PRO-seq libraries from these samples and examined elongation profiles. Analysis of elongation profiles revealed that TIM3 disruption induces pervasive defects of transcription elongation.
Project description:The super elongation complex (SEC) contains the positive transcription elongation factor b (P-TEFb) and a subcomplex, ELL2-EAF1, which stimulates transcription elongation by RNA polymerase II (Pol II). Here we report the cryo-EM structure of ELL2-EAF1 bound to a Pol II elongation complex at 2.8 Å resolution. The ELL2-EAF1 dimerization module directly binds the Pol II lobe, explaining how SEC delivers P-TEFb to Pol II. The same site on the lobe also binds the initiation factor TFIIF, consistent with SEC binding only after the transition from transcription initiation to elongation. Structure-guided functional analysis shows that elongation stimulation requires the dimerization module and an ELL2 protein linker that tethers this module to the Pol II protrusion. Our results show that SEC stimulates elongation allosterically and indicate that this stimulation involves stabilization of a further closed conformation of the Pol II active center cleft.