| Description |
Protein kinase involved in the regulation of transcription (PMID:10574912, PMID:10757782, PMID:11145967, PMID:11575923, PMID:11809800, PMID:11884399, PMID:14701750, PMID:16109376, PMID:16109377, PMID:20930849, PMID:28426094). Member of the cyclin-dependent kinase pair (CDK9/cyclin-T) complex, also called positive transcription elongation factor b (P-TEFb), which facilitates the transition from abortive to productive elongation by phosphorylating the CTD (C-terminal domain) of the large subunit of RNA polymerase II (RNAP II) POLR2A, SUPT5H and RDBP (PMID:10574912, PMID:10757782, PMID:11145967, PMID:11575923, PMID:11809800, PMID:11884399, PMID:14701750, PMID:16109376, PMID:16109377, PMID:20930849, PMID:28426094). This complex is inactive when in the 7SK snRNP complex form (PMID:10574912, PMID:10757782, PMID:11145967, PMID:11575923, PMID:11809800, PMID:11884399, PMID:14701750, PMID:16109376, PMID:16109377, PMID:20930849, PMID:28426094). Phosphorylates EP300, MYOD1, RPB1/POLR2A and AR and the negative elongation factors DSIF and NELF (PMID:9857195, PMID:10912001, PMID:11112772, PMID:12037670, PMID:20081228, PMID:20980437, PMID:21127351). Regulates cytokine inducible transcription networks by facilitating promoter recognition of target transcription factors (e.g. TNF-inducible RELA/p65 activation and IL-6-inducible STAT3 signaling) (PMID:17956865, PMID:18362169). Promotes RNA synthesis in genetic programs for cell growth, differentiation and viral pathogenesis (PMID:10393184, PMID:11112772). P-TEFb is also involved in cotranscriptional histone modification, mRNA processing and mRNA export (PMID:15564463, PMID:19575011, PMID:19844166). Modulates a complex network of chromatin modifications including histone H2B monoubiquitination (H2Bub1), H3 lysine 4 trimethylation (H3K4me3) and H3K36me3; integrates phosphorylation during transcription with chromatin modifications to control co-transcriptional histone mRNA processing (PMID:15564463, PMID:19575011, PMID:19844166). The CDK9/cyclin-K complex has also a kinase activity towards CTD of RNAP II and can substitute for CDK9/cyclin-T P-TEFb in vitro (PMID:21127351). Replication stress response protein; the CDK9/cyclin-K complex is required for genome integrity maintenance, by promoting cell cycle recovery from replication arrest and limiting single-stranded DNA amount in response to replication stress, thus reducing the breakdown of stalled replication forks and avoiding DNA damage (PMID:20493174). In addition, probable function in DNA repair of isoform 2 via interaction with KU70/XRCC6 (PMID:20493174). Promotes cardiac myocyte enlargement (PMID:20081228). RPB1/POLR2A phosphorylation on 'Ser-2' in CTD activates transcription (PMID:21127351). AR phosphorylation modulates AR transcription factor promoter selectivity and cell growth. DSIF and NELF phosphorylation promotes transcription by inhibiting their negative effect (PMID:9857195, PMID:10912001, PMID:11112772). The phosphorylation of MYOD1 enhances its transcriptional activity and thus promotes muscle differentiation (PMID:12037670). |
| Other names |
Cyclin-dependent kinase 9, EC 2.7.11.22, EC 2.7.11.23, C-2K, Cell division cycle 2-like protein kinase 4, Cell division protein kinase 9, Serine/threonine-protein kinase PITALRE, Tat-associated kinase complex catalytic subunit, CDK9, CDC2L4 TAK |
