Cyclin B1 Antibody / CCNB1

This antibody recognizes a protein of 55-62kDa, identified as Cyclin B1. In mammals, Cyclin B1 associates with inactive p34cdc2, which facilitates phosphorylation of p34cdc2 at amino acids Thr-14 and Tyr-15. This maintains the inactive state until the end of G2-phase. The inactive Cyclin B1-p34cdc2 complex continues to accumulate in the cytoplasm until the completion of DNA synthesis, when Cdc25, a specific protein phosphatase, dephosphorylates amino acids Thr-14 and Tyr-15 of p34cdc2 rendering the complex active at the G2/M boundary. This mitotic kinase complex remains active until the metaphase/anaphase transition when Cyclin B1 is degraded. This degradation process is ubiquitin-dependent and is necessary for the cell to exit mitosis. Cyclin B1-p34cdc2 plays a critical role in G2 to M transition.