Multiple P-TEFbs cooperatively regulate the release of promoter-proximally paused RNA polymerase II.

• Type of Material: Article
• Authors: Xiaodong Lu, Emory University; Xinxing Zhu, Xiamen University; You Li, Xiamen University; Min Liu, Xiamen University; Bin Yu, Xiamen University; Yu Wang, Xiamen University; Muhua Rao, Xiamen University; Haiyang Yang, Xiamen University; Kai Zhou, Xiamen University; Yao Wang, Xiamen University; Yanheng Chen, Xiamen University; Meihua Chen, Xiamen University; Songkuan Zhuang, Xiamen University; Lin-Feng Chen, University of Illinois; Runzhong Liu, Xiamen University; Ruichuan Chen, Xiamen University
• Language: English
• Date: 2016-08-19
• Publisher: Oxford University Press
• Publication Version: Final Published Version
• Copyright Statement: © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.
• License: Creative Commons Attribution-NonCommercial 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1093/nar/gkw571
• Title of Journal or Parent Work: Nucleic Acids Res
• Volume: 44
• Issue: 14
• Start Page: 6853
• End Page: 6867
• Grant/Funding Information: National Natural Science Foundation of China [81361120386, 31570751, 31270809 and 30930046 to R.C., 31501096 to M.L., 81171192 to R.L.]; 973 program [2013CB917802 to R.C.]; NIH-CA179511 [to L.F.C.]; Fundamental Research Funds for the Central Universities [20720150053 to M.L.]; NSFC for Fostering Talents in Basic Research [J1310027 to Y.C]. Funding for open access charge: National Natural Science Foundation of China [81361120386, 31570751, 31270809 and 30930046 to R.C., 31501096 to M.L., 81171192 to R.L.]; 973 program [2013CB917802 to R.C.]; NIH-CA179511 [to L.F.C.]; Fundamental Research Funds for the Central Universities [20720150053 to M.L.]; NSFC for Fostering Talents in Basic Research [J1310027 to Y.C].
• Keywords: Nuclear Proteins; HCT116 Cells; Promoter Regions, Genetic; Transcription Factors; Positive Transcriptional Elongation Factor B; HeLa Cells; RNA Polymerase II; Transcription Elongation, Genetic; Acetamides; Phosphorylation; Transcriptional Elongation Factors; Cell Cycle Proteins; Humans; Models, Biological; RNA, Small Interfering
• Research Categories: Biology, Cell; Biology, Genetics

Abstract

The association of DSIF and NELF with initiated RNA Polymerase II (Pol II) is the general mechanism for inducing promoter-proximal pausing of Pol II. However, it remains largely unclear how the paused Pol II is released in response to stimulation. Here, we show that the release of the paused Pol II is cooperatively regulated by multiple P-TEFbs which are recruited by bromodomain-containing protein Brd4 and super elongation complex (SEC) via different recruitment mechanisms. Upon stimulation, Brd4 recruits P-TEFb to Spt5/DSIF via a recruitment pathway consisting of Med1, Med23 and Tat-SF1, whereas SEC recruits P-TEFb to NELF-A and NELF-E via Paf1c and Med26, respectively. P-TEFb-mediated phosphorylation of Spt5, NELF-A and NELF-E results in the dissociation of NELF from Pol II, thereby transiting transcription from pausing to elongation. Additionally, we demonstrate that P-TEFb-mediated Ser2 phosphorylation of Pol II is dispensable for pause release. Therefore, our studies reveal a co-regulatory mechanism of Brd4 and SEC in modulating the transcriptional pause release by recruiting multiple P-TEFbs via a Mediator- and Paf1c-coordinated recruitment network.