CDK7s

CDK7s refers to cyclindependent kinase 7, a critical enzyme involved in the regulation of gene transcription and cell cycle progression. It is a component of the general transcription factor TFIIH, a multi-subunit complex essential for initiating transcription by RNA polymerase II. Within TFIIH, CDK7 acts as a kinase, phosphorylating the C-terminal domain (CTD) of RNA polymerase II. This phosphorylation is a key step in the transition from transcription initiation to elongation.

Beyond its role in transcription, CDK7 is also involved in cell cycle control. It forms a complex with cyclin H and MAT1, known as CDK-activating kinase (CAK). This CAK complex phosphorylates other cyclin-dependent kinases (CDKs), such as CDK1 and CDK2, thereby activating them. These CDKs are crucial for driving the cell cycle through its various phases, including DNA replication and mitosis. Therefore, CDK7 plays a dual role, coordinating both transcriptional activity and cell cycle progression. Dysregulation of CDK7 activity has been implicated in various diseases, including cancer, making it a target for therapeutic intervention.