CDK7

CDK7, also known as Cyclin-dependent kinase 7, is a protein kinase that plays a crucial role in cell cycle regulation and transcription. It is a component of the general transcription factor IIH (TFIIH), a complex essential for the initiation of transcription by RNA polymerase II. Within TFIIH, CDK7 phosphorylates the C-terminal domain of RNA polymerase II, which is necessary for promoter escape and subsequent transcriptional elongation. Additionally, CDK7 acts as a CDK-activating kinase (CAK), meaning it phosphorylates and activates other cyclin-dependent kinases, such as CDK1 and CDK2, which are vital for cell cycle progression.

The activity of CDK7 is tightly regulated by its association with cyclin H and the p37 subunit, forming the CAK complex. This complex's dysregulation has been implicated in various human diseases, including cancer. In cancer cells, CDK7 can be overexpressed or exhibit altered activity, contributing to uncontrolled cell proliferation and survival. Consequently, CDK7 has emerged as a target for the development of anti-cancer therapeutics, with several inhibitors currently under investigation or in clinical trials. These inhibitors aim to block the kinase activity of CDK7, thereby disrupting cell cycle progression and transcription in cancer cells. Research continues to explore the multifaceted roles of CDK7 in both normal cellular processes and disease pathogenesis.