Project description:FACT has been identified as a histone chaperone that enables transcription through chromatin in vitro, but its role in regulating chromatin structure and transcription in vivo remains unclear. In this study, we have investigated the function and molecular mechanism of FACT in unprecedented detail, by using a rapid depletion system in combination with high-resolution genomic analyses. We show that acute depletion of FACT leads to changes in 3D chromatin structure and a concomitant multilayered transcriptional defect, including loss of promoter-proximal pausing, deregulated elongation and increased drop-off of RNA Pol II. Integration of in vitro transcription assays shows that FACT stimulates RNA Pol II pausing by stabilizing nucleosomal architecture, while simultaneously promoting transcription through the +1 nucleosome. In addition to providing detailed mechanistic insight into the seemingly contradictory functions of FACT and the regulation of promoter-proximal pausing, our study indicates a direct coupling of chromatin structure and transcription.
Project description:Transcription by RNA polymerase II (RNA Pol II) depends on transcription factors and chromatin factors. Here we use rapid factor depletion and multiomics analysis to investigate how a histone chaperone, FAcilitates Chromatin Transcription (FACT), influence nascent transcription by RNA PolII in human cells. Depletion of a FACT subunit, SSRP1, led to rapid changes in chromatin structure and concomitantly strongly compromised RNA synthesis. FACT depletion led to a multilayered transcriptional defect, including loss of promoter proximal pausing, deregulated release into elongation and drop-off of RNA Pol II in promoter-distant gene regions. We combined these analyses with biochemical dissection of transcription of a chromatinized template to show that FACT supports both elongation and pausing of RNA Pol II. Our study also provides new evidence how the position of promoter proximal pausing is defined by the +1 nucleosome in human cells.
Project description:Transcription by RNA polymerase II (RNA Pol II) depends on transcription factors and chromatin factors. Here we use rapid factor depletion and multiomics analysis to investigate how a histone chaperone, FAcilitates Chromatin Transcription (FACT), influence nascent transcription by RNA PolII in human cells. Depletion of a FACT subunit, SSRP1, led to rapid changes in chromatin structure and concomitantly strongly compromised RNA synthesis. FACT depletion led to a multilayered transcriptional defect, including loss of promoter proximal pausing, deregulated release into elongation and drop-off of RNA Pol II in promoter-distant gene regions. We combined these analyses with biochemical dissection of transcription of a chromatinized template to show that FACT supports both elongation and pausing of RNA Pol II. Our study also provides new evidence how the position of promoter proximal pausing is defined by the +1 nucleosome in human cells.
Project description:Transcription by RNA polymerase II (RNA Pol II) depends on transcription factors and chromatin factors. Here we use rapid factor depletion and multiomics analysis to investigate how a histone chaperone, FAcilitates Chromatin Transcription (FACT), influence nascent transcription by RNA PolII in human cells. Depletion of a FACT subunit, SSRP1, led to rapid changes in chromatin structure and concomitantly strongly compromised RNA synthesis. FACT depletion led to a multilayered transcriptional defect, including loss of promoter proximal pausing, deregulated release into elongation and drop-off of RNA Pol II in promoter-distant gene regions. We combined these analyses with biochemical dissection of transcription of a chromatinized template to show that FACT supports both elongation and pausing of RNA Pol II. Our study also provides new evidence how the position of promoter proximal pausing is defined by the +1 nucleosome in human cells.