CDK9 (cyclin-dependent kinase 9) is a member of the cyclin-dependent protein kinase family. It is involved in the regulation of transcription. CDK9 is a member of the cyclin-dependent kinase pair (CDK9/cyclin-T) complex. This complex facilitates the transition from abortive to productive elongation by phosphorylating the CTD of the large subunit of RNA polymerase II, POLR2A, SUPT5H, and RDBP. The complex is inactive when in the 7SK snRNP complex form. CDK9 phosphorylates EP300, MYOD1, RPB1/POLR2A, AR, DSIF, and NELF. It regulates cytokine inducible transcription networks by facilitating promoter recognition of target transcription factors. CDK9 promotes RNA synthesis in genetic programs for cell growth, differentiation, and viral pathogenesis. The CDK9/cyclin-K complex also has kinase activity towards CTD of RNAPII and can substitute for CDK9/cyclin-T P-TEFb in vitro. Chronic activation of CDK9 causes cardiac myocyte enlargement leading to cardiac hypertrophy and confers a predisposition to heart failure.
Protein Aliases: C-2K; CDC2-related kinase; Cell division cycle 2-like protein kinase 4; Cell division protein kinase 9; Cyclin-dependent kinase 9; cyclin-dependent kinase 9 (CDC2-related kinase); RP11-228B15.5; serine/threonine protein kinase PITALRE; Serine/threonine-protein kinase PITALRE; Tat-associated kinase complex catalytic subunit
Gene Aliases: C-2k; CDC2L4; CDK9; CTK1; PITALRE; TAK
Molecular Function: non-receptor serine/threonine protein kinase