Technical Articles

Cyclin A2 is the core S-phase and M-phase cyclin that activates CDK2 and CDC2. This article explains its expression timing, the E174-L432 construct boundary and how recombinant Cyclin A2 supports kinase and complex-reconstitution studies.

CDK2 binds to different cyclins (such as Cyclin E and Cyclin A) to form active complexes that drive the transition of key cell cycle checkpoints. During the transition from G1 phase to S phase, the CDK2-Cyclin E complex plays a critical role. It phosphorylates a series of substrates, such as the retinoblastoma protein (Rb), releasing the transcription factor E2F, thereby initiating the transcription of DNA replication-related genes and promoting the cell's entry into S phase for DNA synthesis.