PKMYT1

PKMYT1, or Myt1, is the membrane-associated member of the Wee1 family of inhibitory kinases. Whereas Wee1 acts in the nucleus, Myt1 is anchored to Golgi and endoplasmic-reticulum membranes and phosphorylates cyclin B-CDK1 on Thr14 as well as Tyr15, keeping the complex inactive in the cytoplasm throughout interphase. At the G2/M transition, Myt1 is itself inactivated by phosphorylation, releasing active CDK1 into mitosis. PKMYT1 also restrains CDK2 and helps protect against premature mitotic entry after DNA damage. Because many cancers depend on PKMYT1 to buffer CDK1 activity, the kinase is an emerging combination-therapy target. Recombinant PKMYT1 enables cell-cycle inhibitor research.