Regulation of the human WEE1Hu CDK tyrosine 15-kinase during the cell cycle.

摘要: Abstract In higher eukaryotes, the cyclin-dependent kinases (CDKs) are negatively regulated by phosphorylation on threonine 14 (T14) and tyrosine 15 (Y15). In fission yeast, Wee1 mitosis inhibitory kinase 1 (Mik1) protein phosphorylate Y15 in Cdc2. WEE1Hu is only known that can carry out this eukaryotes. present study, we examined endogenous products of human cells found original cDNA lacked 214 amino acids at N-terminus. The predicted full-length has weak, but significant, similarity over its entire length with Mik1. Thus, suggest 'WEE1Hu' a Mik1-related rather than homologue. When isolated immunoprecipitates, phosphorylated several cyclin-associated CDKs Y15. activity increased during S G2 phases parallel level protein. Its decreased M phase when became transiently hyperphosphorylated. addition, decrease was observed M/G1 phase. Apparently, hyperphosphorylation degradation combination caused inactivation following G1 These results proteolytic degradation, plays role inhibiting before phosphorylating cyclin B1-Cdc2.