The cell cycle inhibitor p21CIP is phosphorylated by cyclin A-CDK2 complexes

Biochem Biophys Res Commun. 1997 Dec 18;241(2):434-8. doi: 10.1006/bbrc.1997.7787.

ABSTRACT

We report here experimental evidence indicating that the p21CIP, the universal inhibitor of cyclin-dependent protein kinases, general inhibitor CDKs is a substrate oof cyclin A-cdk2. The evidence comes from phosphorylation experiments in which the endogenous p21CIP present in using the original cyclin A-cdk2 complexes immunoprecipitated from HeLa cells extracts can be phosphorylated by the cdk2 of the same complexes. In vitro experiments showing that reconstituted GSTcyclin A-GSTcdk2 complexes from phosphorylate recombinant GSTp21CIP confirms that p21CIP is a cyclin A-cdk2 substrate.

PMID:9425288 | DOI:10.1006/bbrc.1997.7787