The role of the RNA Polymerase II CTD kinases in regulation of transcription, RNA processing and the cell cycle.

The multiple Tyr1Ser2Pro3Thr4Ser5Pro6Ser7 repeats within the carboxyl-terminal domain (CTD) of the large subunit of RNA polymerase II (pol II) undergo reversible phosphorylation during transcription of human protein-coding genes1. CTD phosphorylation ensures the sequential recruitment of transcription and RNA processing factors required for correct gene expression and requires several cyclin-dependent kinases (CDKs), including CDK7, CDK8, CDK9 and CDK12 .
It is now becoming clear that these ‘CTD’ kinases have multiple additional targets that may also play key roles in transcription, RNA processing and the cell cycle. The aim of the proposed research is to understand the precise role(s) that CTD kinases play in cellular processes through modification of the CTD and other factors, what molecular mechanisms are involved and how their activities are co-ordinated. Towards this goal, we have produced human cell lines expressing analogue-sensitive versions of several CTD kinases that can be rapidly and selectively inhibited in living cells. These cell lines will be used to determine the direct effect of loss of CTD kinase activity, to identify the primary targets of these kinases and to characterize the molecular interactions underlying their functions.