Wee1 kinase inhibition in G2 phase leads to:
G2 progression is gated by inhibitory phosphorylation of master mitotic kinase CDK1 that prevents premature mitotic entry while last preparations complete. Nuclear kinase Wee1 and membrane-associated Myt1 phosphorylate CDK1 subunit within cyclin B-CDK1 complex at Tyr15 and Thr14 within ATP-binding loop, rendering kinase catalytically inactive despite abundant cyclin B synthesized during G2, allowing centrosome maturation, Golgi segregation, and DNA repair synthesis to proceed. At G2/M border, dual-specificity phosphatases Cdc25A/B/C remove these phosphates, causing explosive autoamplification
Ref: Harper & Elledge, Mol Biol Cell 2007, Wee1 Control. Alberts 7th ed., Chapter 17, CDK1 Regulation.