Synonyms: C-2K,CDC2 related kinase,CDC2L4,Cdk 9,Cdk9,CDK9,Cell division cycle 2-like protein kinase 4,Cell division protein kinase 9,CTK1,Cyclin dependent kinase 9,Cyclin-dependent kinase 9,PITALRE,Serine/threonine-protein kinase PITALRE,TAK,Tat associated kinase complex catalytic subunit
Background: The protein encoded by this gene is a member of the cyclin-dependent protein kinase (CDK) family. CDK family members are highly similar to the gene products of S. cerevisiae cdc28, and S. pombe cdc2, and known as important cell cycle regulators. This kinase was found to be 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. This protein forms a complex with and is regulated by its regulatory subunit cyclin T or cyclin K. HIV-1 Tat protein was found to interact with this protein and cyclin T, which suggested a possible involvement of this protein in AIDS.