title: Mitotic phosphatases: no longer silent partners.
abstract: Recent work has highlighted the important role played by protein phosphatase complexes in the regulation of mitosis from yeast to mammals. There have been important advances in defining the roles of the protein serine/threonine phosphatases PP1 and PP2A and the dual specificity protein tyrosine phosphatases CDC25 and Cdc14. Three independent studies defined a regulatory role for PP2A in the control of sister chromatid cohesion, involving a direct interaction with shugoshin. A chromatin targeting subunit has been identified for PP1 and the complex shown to play an essential role in chromosome segregation. Key regulatory residues within CDC25 have been mapped and its activity tied both to the initial activation of cyclin-dependent kinases at the centrosome and to DNA damage checkpoints. Novel roles have been defined for Cdc14, including regulation of rDNA and telomere segregation and participation in spindle assembly. These exciting advances show that protein phosphatases are not merely silent partners to kinases in regulating the control of cell division.
authors.affiliation: Division of Gene Regulation & Expression, School of Life Sciences, University of Dundee, Dow St., Dundee DD1 5EH, UK. l.trinklemulcahy@dundee.ac.uk
authors.forename: Laura
authors.initials: L
authors.lastname: Trinkle-Mulcahy
authors.forename: Angus I
authors.initials: AI
authors.lastname: Lamond
mesh_terms: D000818:Animals; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D020090:Chromosome Segregation / Q000235:genetics; D018844:Cyclin-Dependent Kinases / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008938:Mitosis / Q000235:genetics*; D010749:Phosphoprotein Phosphatases / Q000235:genetics / Q000378:metabolism*; D010744:Phosphoric Monoester Hydrolases / Q000235:genetics / Q000378:metabolism*; D017027:Protein Tyrosine Phosphatases; D008941:Spindle Apparatus / Q000235:genetics / Q000378:metabolism; D020687:cdc25 Phosphatases / Q000235:genetics / Q000378:metabolism*
chemical_list: D018797:Cell Cycle Proteins; D018844:Cyclin-Dependent Kinases; D010749:Phosphoprotein Phosphatases; D010744:Phosphoric Monoester Hydrolases; C120902:CDC14A protein, human; D017027:Protein Tyrosine Phosphatases; D020687:cdc25 Phosphatases