CDK9/CyclinT2, Active

CDK9/Cyclin T2 is a member of the cyclin-dependent protein kinase (CDK) family which are known to be important regulators of cell cycle progression. Cyclin T2 and its kinase partner CDK9 are found to be subunits of the transcription elongation factor p-TEFb. The p-TEFb complex containing this cyclin has been reported to interact with, and act as a negative regulator of human immunodeficiency virus type 1 (HIV-1) Tat protein (1). The transcription-dependent interaction of P-TEFb with 7SK may therefore contribute to an important feedback loop modulating the activity of RNA Pol II (2).