Cyclin-dependent kinase 2 (CDK2) in complex with Cyclin A2 (CCNA2) (CDK2/Cyclin A2)

Cyclin-dependent kinase 2 (CDK2) in complex with Cyclin A2 is a critical serine/threonine kinase that orchestrates key transitions in the mammalian cell cycle, particularly the progression through S phase and the onset of G2 (PubMed: 22539939). The catalytic activity of CDK2 is strictly dependent on its association with the regulatory Cyclin A2 subunit, which induces a conformational change in the kinase's T-loop and PSTAIRE helix to allow ATP binding and substrate access (Wikipedia). This complex phosphorylates essential targets such as the retinoblastoma protein (Rb) and E2F transcription factors, thereby promoting DNA replication and genomic stability (UniProt: P24941). Overexpression or hyperactivation of the CDK2/Cyclin A2 complex is frequently observed in various cancers, including breast, ovarian, and lung carcinomas, making it a high-priority therapeutic target (PubMed: 25444661). While early pan-CDK inhibitors like flavopiridol were limited by toxicity, modern drug development focuses on selective CDK2 inhibitors such as PF-07104091 and BLU-222, as well as novel non-ATP competitive inhibitors that disrupt the protein-protein interface (ClinicalTrials.gov: NCT04553133). These targeted therapies aim to arrest the cell cycle in malignant cells while minimizing the systemic side effects associated with broader kinase inhibition. Additionally, the complex has been implicated in non-canonical roles such as DNA repair and cytoskeletal regulation, expanding its relevance beyond simple cell cycle control (PubMed: 34017010). Monitoring biomarkers like Cyclin A2 levels and p21 expression is essential for identifying patients likely to respond to these inhibitors.

Other names

CDK2-CCNA2 complexp33CDK2/Cyclin A2Cyclin-dependent kinase 2/Cyclin A2 complexCDK2/CycA2Cyclin A2-CDK2

Inhibition of kinase activity through ATP-competitive binding to the CDK2 subunit or disruption of the protein-protein interaction between the CDK2 catalytic subunit and the Cyclin A2 regulatory subunit, leading to cell cycle arrest.