Acts as an inhibitor of serine/threonine-protein phosphatase 2A (PP2A) activity (, ). Potentiates ubiquitin-mediated proteasomal degradation of serine/threonine-protein phosphatase 2A catalytic subunit alpha (PPP2CA) . Inhibits PP2A-mediated dephosphorylation of WEE1, promoting ubiquitin-mediated proteolysis of WEE1, thereby releasing G2/M checkpoint .
Subcellular locations: Nucleus, Cytoplasm
The CHEK1-mediated Ser-37 phosphorylated form is sequestered by 14-3-3 proteins in the cytoplasm and fails to translocate to the nucleus, where it otherwise inhibits serine/threonine-protein phosphatase 2A.