title: The polo-like kinase 1 regulates CDC25B-dependent mitosis entry.
abstract: Activation of cyclin-dependent kinase complexes (CDK) at key cell cycle transitions is dependent on their dephosphorylation by CDC25 dual-specificity phosphatases (CDC25A, B and C in human). The CDC25B phosphatase plays an essential role in controlling the activity of CDK1-cyclin B complexes at the entry into mitosis and together with polo-like kinase 1 (PLK1) in regulating the resumption of cell cycle progression after DNA damage-dependent checkpoint arrest in G2. In this study, we analysed the regulation of CDC25B-dependent mitosis entry by PLK1. We demonstrate that PLK1 activity is essential for the relocation of CDC25B from the cytoplasm to the nucleus. By gain and loss of function analyses, we show that PLK1 stimulates CDC25B-induced mitotic entry in both normal conditions and after DNA-damage induced G2/M arrest. Our results support a model in which the relocalisation of CDC25B to the nucleus at the G2-M transition by PLK1 regulates its mitotic inducing activity.
authors.affiliation: Université de Toulouse, LBCMCP, 118 Route de Narbonne, CNRS, LBCMCP-UMR5088, F-31062 Toulouse, France.
authors.forename: Valerie
authors.initials: V
authors.lastname: Lobjois
authors.forename: Denis
authors.initials: D
authors.lastname: Jullien
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Bouché
authors.forename: Bernard
authors.initials: B
authors.lastname: Ducommun
mesh_terms: D018797:Cell Cycle Proteins / Q000378:metabolism*; D002455:Cell Division; D002467:Cell Nucleus / Q000378:metabolism; D002478:Cells, Cultured; D003593:Cytoplasm / Q000378:metabolism; D004249:DNA Damage; D005455:Fluorescent Antibody Technique; D016195:G2 Phase; D006801:Humans; D008938:Mitosis / Q000502:physiology*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D014162:Transfection; D020687:cdc25 Phosphatases / Q000032:analysis / Q000378:metabolism*; D000097869:Polo-Like Kinase 1
chemical_list: D018797:Cell Cycle Proteins; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D020687:cdc25 Phosphatases; D000097869:Polo-Like Kinase 1