a protein kinase of the CDK family. Forms a complex with and is regulated by its regulatory subunit cyclin T or cyclin K. A component of the multiprotein complex TAK/P-TEFb, which is an elongation factor for RNA polymerase II-directed transcription and functions by phosphorylating the C-terminal domain of the largest subunit of RNA polymerase II. Transcriptional elongation factor and cofactor for HIV Tat protein; RNAi blocks HIV replication, and inhibitors also block varicella zoster replication. Mediates signals leading to cardiac hypertrophy. Inhibitor: Flavopiridol. Note: This description may include information from UniProtKB.
Protein type: CDK family; CDK/CDK9 subfamily; CDK9 subfamily; CMGC group; Cell cycle regulation; EC 126.96.36.199; EC 188.8.131.52; Kinase, protein; Nuclear receptor co-regulator; Protein kinase, CMGC; Protein kinase, Ser/Thr (non-receptor)
Molecular Function: chromatin binding; cyclin-dependent protein kinase activity; DNA binding; kinase activity; protein binding; protein kinase activity; protein serine/threonine kinase activity; RNA polymerase subunit kinase activity
Biological Process: cell proliferation; positive regulation of histone phosphorylation; positive regulation of transcription from RNA polymerase II promoter; positive regulation of viral transcription; protein amino acid phosphorylation; regulation of DNA repair; regulation of histone modification; regulation of mitotic cell cycle; regulation of muscle cell differentiation; replication fork processing; RNA elongation from RNA polymerase II promoter; snRNA transcription from RNA polymerase II promoter; transcription from RNA polymerase II promoter; transcription initiation from RNA polymerase II promoter