title: Study of the docking-dependent PLK1 phosphorylation of the CDC25B phosphatase.
abstract: CDC25 (A, B and C) phosphatases control cell cycle progression through the timely dephosphorylation and activation of cyclin-dependent kinases (CDK). At mitosis the CDC25B phosphatase activity is dependent on its phosphorylation by multiple kinases impinging on its localisation, stability and catalytic activity. Here we report that prior phosphorylation of CDC25B by CDK1 enhances its substrate properties for PLK1 in vitro, and we also show that phosphorylated S50 serves as a docking site for PLK1. Using a sophisticated strategy based on the sequential phosphorylation of CDC25B with (16)O and (18)O ATP prior to nanoLC-MS/MS analysis we identified 13 sites phosphorylated by PLK1. This study illustrates the complexity of the phosphorylation pattern and of the subsequent regulation of CDC25B activity.
authors.affiliation: Université de Toulouse, LBCMCP, F-31062 Toulouse, France.
authors.forename: Valérie
authors.initials: V
authors.lastname: Lobjois
authors.forename: Carine
authors.initials: C
authors.lastname: Froment
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Braud
authors.forename: Fanny
authors.initials: F
authors.lastname: Grimal
authors.forename: Odile
authors.initials: O
authors.lastname: Burlet-Schiltz
authors.forename: Bernard
authors.initials: B
authors.lastname: Ducommun
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Bouche
mesh_terms: D000595:Amino Acid Sequence; D018797:Cell Cycle Proteins / Q000378:metabolism*; D006801:Humans; D008969:Molecular Sequence Data; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D012694:Serine / Q000235:genetics / Q000378:metabolism*; D020687:cdc25 Phosphatases / Q000235:genetics / Q000378:metabolism*; D000097869:Polo-Like Kinase 1
chemical_list: D018797:Cell Cycle Proteins; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D012694:Serine; D020687:cdc25 Phosphatases; D000097869:Polo-Like Kinase 1; C517008:CDC25B protein, human