Cyclin-dependent kinase control of the initiation-to-elongation switch of RNA polymerase II.
Promoter-proximal pausing by RNA polymerase II (Pol II) ensures gene-specific regulation and RNA quality control. Structural considerations suggested a requirement for initiation-factor eviction in elongation-factor engagement and pausing of transcription complexes. Here we show that selective inhibition of Cdk7--part of TFIIH--increases TFIIE retention, prevents DRB sensitivity-inducing factor (DSIF) recruitment and attenuates pausing in human cells. Pause release depends on Cdk9-cyclin T1 (P-TEFb); Cdk7 is also required for Cdk9-activating phosphorylation and Cdk9-dependent downstream events--Pol II C-terminal domain Ser2 phosphorylation and histone H2B ubiquitylation--in vivo. Cdk7 inhibition, moreover, impairs Pol II transcript 3'-end formation. Cdk7 thus acts through TFIIE and DSIF to establish, and through P-TEFb to relieve, barriers to elongation: incoherent feedforward that might create a window to recruit RNA-processing machinery. Therefore, cyclin-dependent kinases govern Pol II handoff from initiation to elongation factors and cotranscriptional RNA maturation.
Department of Structural and Chemical Biology, Mount Sinai School of Medicine, New York, New York, USA.
Stéphane
S
Larochelle
Ramon
R
Amat
Kira
K
Glover-Cutter
Miriam
M
Sansó
Chao
C
Zhang
Jasmina J
JJ
Allen
Kevan M
KM
Shokat
David L
DL
Bentley
Robert P
RP
Fisher
D047369:Chromatin Immunoprecipitation; D042863:Cyclin-Dependent Kinase 9 / Q000378:metabolism; D018844:Cyclin-Dependent Kinases / Q000378:metabolism / Q000502:physiology*; D045325:HCT116 Cells; D006657:Histones / Q000378:metabolism; D006801:Humans; D015151:Immunoblotting; D009687:Nuclear Proteins / Q000378:metabolism; D010766:Phosphorylation; D012319:RNA Polymerase II / Q000378:metabolism*; D061805:Transcription Elongation, Genetic / Q000502:physiology*; D014157:Transcription Factors / Q000378:metabolism; D019473:Transcription Factors, TFII / Q000378:metabolism; D061785:Transcription Initiation, Genetic / Q000502:physiology*; D035602:Transcriptional Elongation Factors; D054875:Ubiquitination; D000095043:Cyclin-Dependent Kinase-Activating Kinase
D006657:Histones; D009687:Nuclear Proteins; C112224:SUPT5H protein, human; D014157:Transcription Factors; D019473:Transcription Factors, TFII; D035602:Transcriptional Elongation Factors; C066644:transcription factor TFIIE; C467969:CDK9 protein, human; D042863:Cyclin-Dependent Kinase 9; D018844:Cyclin-Dependent Kinases; D012319:RNA Polymerase II; D000095043:Cyclin-Dependent Kinase-Activating Kinase; C000722416:CDK7 protein, human