WEE1, a nuclear kinase, phosphorylates cyclin B1:Cdc2 (CC...

WEE1, a nuclear kinase, phosphorylates cyclin B1:Cdc2 (CCNB1:CDK1) on tyrosine 15 (Y15), inactivating the complex (Parker and Piwnica-Worms 1992, McGowan and Russell 1993, Watanabe et al., 1995). The complex of cyclin B2 and Cdc2 (CCNB2:CDK1) is also phosphorylated on Y15 (Galaktionov and Beach 1991). Two-dimensional gel electrophoresis of protein extracts of cycling human cells has shown that CDK1 triple phosphorylated at T14, Y15, and T161 is the most abundant form of CDK1 that co-immunoprecipitates with CCNA2 or CCNB1, and Y15 phosphorylation of CDK1 was confirmed to be WEE1-dependent (Coulonval et al. 2011).

CCNA:CDK1-mediated phosphorylation of WEE1 inhibiting WEE1 kinase activity and facilitates the activation of CCNB:CDK1 complexes (Deibler and Kirschner 2010).