TFIIH kinase CDK7 drives cell proliferation through a common core transcription factor network
We combined cryo-EM, transcriptomics, and a clinically relevant inhibitor to define how the TFIIH-associated CDK7 kinase coordinately controls the cell cycle and RNA polymerase II (RNAPII) transcription. CDK7 inhibition rapidly blocked expression of constitutively active genes, whereas inducible genes were unaffected.  Distinct sets of sequence-specific, DNA-binding transcription factors (TFs) regulate constitutive vs. inducible genes; accordingly, inducible TFs (e.g. HSF1) were refractory to CDK7 inhibition. By contrast, CDK7 was required to maintain activity of a core set of promoter-associated TFs that drive proliferative gene expression programs; these core TFs (n=78) are constitutively active in proliferating cells. Thus, a major biological function for CDK7 is regulation of TFs that drive cell proliferation, revealing an apparent universal mechanism by which CDK7 coordinates RNAPII transcription with cell cycle regulation. Overall design: RNA-seq in OV90 cells was performed to evaluate the effects of CDK7 inhibition under basal conditions at 4hrs. There are 3 biological replicates for each condition.