title: Human Cdc14A reverses CDK1 phosphorylation of Cdc25A on serines 115 and 320.
abstract: Human Cdc14A is an evolutionary conserved dual-specificity protein phosphatase that reverses the modifications effected by cyclin-dependent kinases and plays an important role in centrosome duplication and mitotic regulation. Few substrates of Cdc14A have been identified, some of them with homologues in yeast that, in turn, are substrates of the Saccharomyces cerevisiae Cdc14 homologue, a protein phosphatase essential for yeast cell viability owing its role in mitotic exit regulation. Identification of the physiological substrates of human Cdc14A is an immediate goal in order to elucidate which cellular processes it regulates. Here, we show that human Cdc14A can dephosphorylate Cdc25A in vitro. Specifically, the Cdk1/Cyclin-B1-dependent phosphate groups on Ser115 and Ser320 of Cdc25A were found to be removed by Cdc14A. Cdc25A is an important cell cycle-regulatory protein involved in several cell cycle transitions and checkpoint responses and whose function and own regulation depend on complex phosphorylation/dephosphorylation-mediated processes. Importantly, we also show that the upregulation of Cdc14A phosphatase affects Cdc25A protein levels in human cells. Our results suggest that Cdc14A may be involved in the cell cycle regulation of Cdc25A stability.
authors.affiliation: Centro de Investigación del Cáncer, Universidad de Salamanca/CSIC, Salamanca, Spain.
authors.forename: Verónica
authors.initials: V
authors.lastname: Esteban
authors.forename: María D
authors.initials: MD
authors.lastname: Vázquez-Novelle
authors.forename: Enrique
authors.initials: E
authors.lastname: Calvo
authors.forename: Avelino
authors.initials: A
authors.lastname: Bueno
authors.forename: María P
authors.initials: MP
authors.lastname: Sacristán
mesh_terms: D000595:Amino Acid Sequence; D016203:CDC2 Protein Kinase / Q000378:metabolism*; D019926:Cyclin B / Q000378:metabolism; D056744:Cyclin B1; D006801:Humans; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism*; D010766:Phosphorylation; D010768:Phosphoserine / Q000378:metabolism*; D017027:Protein Tyrosine Phosphatases; D020687:cdc25 Phosphatases / Q000737:chemistry* / Q000378:metabolism*
chemical_list: C534699:CCNB1 protein, human; D019926:Cyclin B; D056744:Cyclin B1; D010768:Phosphoserine; D016203:CDC2 Protein Kinase; D010744:Phosphoric Monoester Hydrolases; C120902:CDC14A protein, human; C517004:CDC25A protein, human; D017027:Protein Tyrosine Phosphatases; D020687:cdc25 Phosphatases