Serine/threonine-protein kinase Chk2 (CHEK2)

Serine/threonine-protein kinase that's required for checkpoint-mediated cell cycle arrest, activation of DNA repair and apoptosis in response to the presence of DNA double-strand breaks. Following activation, phosphorylates numerous effectors preferentially in the consensus sequence [L-X- R-X-X-S/T].

Inhibition of CDC25 phosphatase activity leads to increased inhibitory tyrosine phosphorylation of CDK-cyclin complexes and blocks cell cycle progression. May also phosphorylate NEK6 that's involved in G2/M cell cycle arrest.