CAP20,CDK-interacting protein 1,CDK-interaction protein 1,CDKN1,CIP1,cyclin-dependent kinase inhibitor 1,cyclin-dependent kinase inhibitor 1A (p21, Cip1),DNA synthesis inhibitor,MDA-6,melanoma differentiation associated protein 6,Melanoma differentiation-associated protein 6,P21,p21CIP1,SDI1,WAF1,wild-type p53-activated fragment 1.
May be involved in p53/TP53 mediated inhibition of cellular proliferation in response to DNA damage. Binds to and inhibits cyclin-dependent kinase activity, preventing phosphorylation of critical cyclin-dependent kinase substrates and blocking cell cycle progression. Functions in the nuclear localization and assembly of cyclin D-CDK4 complex and promotes its kinase activity towards RB1. At higher stoichiometric ratios, inhibits the kinase activity of the cyclin D-CDK4 complex. Inhibits DNA synthesis by DNA polymerase delta by competing with POLD3 for PCNA binding (PubMed:11595739).
