Serine/threonine-protein kinase Chk1 (CHEK1)

Serine/threonine-protein kinase which is needed for checkpoint-mediated cell cycle arrest and activation of DNA repair in response to the presence of DNA damage or unreplicated DNA. This regulation is achieved by a range of mechanisms that collectively help to keep the integrity of the genome.

Binds to and phosphorylates CDC25A, CDC25B and CDC25C. Phosphorylation of CDC25A in'Ser-178' and'Thr-507' and phosphorylation of CDC25C in'Ser-216' creates binding sites for 14-3-3 proteins that inhibit CDC25A and CDC25C.