Model for regulation of Wee1 by cyclin A/Cdk2 complexes. Wee1 is depicted as a cyclin B/Cdk1 Y15 kinase with a globular kinase domain (dark blue) and a relatively unstructured NRD (light blue). The Cyclin A/Cdk2 complex binds RxL1 and phosphorylates T239. It might also phosphorylate a Wee1 residue that contributes to Crm1 binding (dashed arrow to S/TX). Crm1 binds the NES and possibly the additional cyclin A/Cdk2 phosphorylation site (dashed line) and mediates Wee1 export from the nucleus. S phase substrates possessing RxL motifs compete with cyclin A/Cdk2 complexes for binding to Wee1.