Cyclin-dependent kinase 2 (CDK2)

Serine/threonine-protein kinase involved in the control of the cell cycle; essential for meiosis, but dispensable for mitosis. Triggers duplication of centrosomes and DNA.

Acts in the G1-S transition to advertise the E2F transcriptional program and the initiation of DNA synthesis, and modulates G2 development; controls the timing of entry into mitosis/meiosis by controlling the subsequent activation of cyclin B/CDK1 by phosphorylation, and coordinates the activation of cyclin B/CDK1 in the centrosome and in the nucleus. Activity of CDK2 is maximal during S phase and G2; activated by interaction with cyclin E during the first stages of DNA synthesis to allow G1-S transition, and then activated by cyclin A2 (cyclin A1 in germ cells) during the late stages of DNA replication to induce the transition from S phase to mitosis, the G2 phase.