CDKN1A Protein, Mouse (His)

The CDKN1A protein assumes a crucial role in controlling cell cycle progression and orchestrating DNA damage-induced G2 arrest. It actively participates in p53/TP53-mediated inhibition of cellular proliferation in response to DNA damage and is also implicated in p53-independent DNA damage-induced G2 arrest, mediated by CREB3L1 in astrocytes and osteoblasts. Functionally, CDKN1A binds to and inhibits cyclin-dependent kinase activity, preventing the phosphorylation of critical cyclin-dependent kinase substrates and thereby blocking cell cycle progression. It contributes to the nuclear localization and assembly of the cyclin D-CDK4 complex, promoting its kinase activity towards RB1. At higher stoichiometric ratios, CDKN1A inhibits the kinase activity of the cyclin D-CDK4 complex and competes with POLD3 for PCNA binding, leading to the inhibition of DNA synthesis by DNA polymerase delta. The intricate regulatory network of CDKN1A includes interactions with HDAC1, MKRN1, PSMA3, CDK4, CDK2, PIM1, STK11, NUAK1, and TRIM39 isoforms, reflecting its diverse role in cell cycle regulation and DNA damage response.