CyclinH Protein

Cyclin H is related to the highly conserved cyclin family. Cyclin family members are characterized by a dramatic periodicity in protein abundance through the cell cycle. Cyclins function as regulators of CDK kinases. Cyclin H forms a complex with CDK7 kinase and the ring finger protein MAT1 which is able to phosphorylate CDK2 and CDC2 kinases and thus act as a CDK-activating kinase (CAK) (1). Cdk-activating kinase complex is a component of human transcription factor TFIIH and plays an important role in the processes of transcription, DNA repair, and cell cycle progression (2).