Inactivation of Wee1 kinase *Plk1 is shown to phosphorylate Wee1A, an event that is likely critical for recognition and ubiquitination of Wee1A by SCF and therefore for the subsequent degradation of Wee1A . **Plk1 phosphorylates Wee1A at S53, creating the second phosphodegron, PD53. ** Evidence also exists in budding yeast that the budding yeast polo homolog Cdc5 directly phosphorylates and down-regulate the budding yeast Wee1 ortholog Swe1. Thus, polo kinase-dependent phosphorylation and degradation of Wee1A (or Swe1) is likely conserved throughout evolution and is critical for normal mitotic entry. Authored: Watanabe, N, Hunter, T, 2008-05-07 23:35:33 EC Number: 2.7.11 Edited: Gillespie, ME, 0000-00-00 00:00:00 GENE ONTOLOGYGO:0051726 Pubmed15037762 Pubmed15070733 Pubmed7681363 Pubmed8515817 Reactome Database ID Release 43156699 Reactome, http://www.reactome.org ReactomeREACT_1944