Phosphorylation of the C-terminal domain of RNA polymerase II plays central roles in the integrated events of eucaryotic gene expression.
RNA polymerase II (Pol II) is the only polymerase to possess heptapeptide repeats in the C-terminal domain (CTD) of its large subunit. During transcription, CTD phopshorylation occurs and is maintained from initiation to termination. To date, among the three known CTD kinases possessing CDK-cyclin pairs, TFIIH is the only one that forms a preinitiation complex. The Mediator complex plays essential roles in transcription initiation and during the transition from initiation to elongation by transmitting signals from transcriptional activators to Pol II. P-TEFb specifically plays a role in transcription elongation. TFIIH and mediator phosphorylate serine 5 (Ser5) of the CTD heptapeptide repeat sequence, whereas P-TEFb phosphorylates serine 2 (Ser2). Recently, it has become clear that CTD phosphorylation is not only essential for transcription, but also as a platform for RNA processing and chromatin regulation. In this review, we discuss the central role of Pol II phosphorylation in these nuclear events.
Hirose
Yutaka
Y
Laboratory of Gene Regulation, Graduate School of Medical and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan.
Ohkuma
Yoshiaki
Y
D048868:Adaptor Proteins, Signal Transducing; D006801:Humans; D008954:Models, Biological; D008958:Models, Molecular; D009687:Nuclear Proteins / Q000502:physiology; D009713:Nucleotidyltransferases / Q000378:metabolism; D010766:Phosphorylation; D011487:Protein Conformation / Q000187:drug effects; D017434:Protein Structure, Tertiary / Q000502:physiology; D012319:RNA Polymerase II / Q000378:metabolism*; D012322:RNA Precursors / Q000378:metabolism; D012323:RNA Processing, Post-Transcriptional / Q000502:physiology; D012326:RNA Splicing / Q000502:physiology; D014158:Transcription, Genetic / Q000502:physiology*; D000098556:mRNA Guanylyltransferases
D048868:Adaptor Proteins, Signal Transducing; D009687:Nuclear Proteins; C472862:PCIF1 protein, human; D012322:RNA Precursors; D009713:Nucleotidyltransferases; D012319:RNA Polymerase II; D000098556:mRNA Guanylyltransferases