title: Budding yeast Swe1 is involved in the control of mitotic spindle elongation and is regulated by Cdc14 phosphatase during mitosis.
abstract: Cyclin-dependent kinase (Cdk1) activity is required for mitotic entry, and this event is restrained by an inhibitory phosphorylation of the catalytic subunit Cdc28 on a conserved tyrosine (Tyr(19)). This modification is brought about by the protein kinase Swe1 that inhibits Cdk1 activation thus blocking mitotic entry. Swe1 levels are regulated during the cell cycle, and they decrease during G2/M concomitantly to Cdk1 activation, which drives entry into mitosis. However, after mitotic entry, a pool of Swe1 persists, and we collected evidence that it is involved in controlling mitotic spindle elongation. We also describe that the protein phosphatase Cdc14 is implicated in Swe1 regulation; in fact, we observed that Swe1 dephosphorylation in vivo depends on Cdc14 that, in turn, is able to control its subcellular localization. In addition we show that the lack of Swe1 causes premature mitotic spindle elongation and that high levels of Swe1 block mitotic spindle elongation, indicating that Swe1 inhibits this process. Importantly, these effects are not dependent upon the role of in Cdk1 inhibition. These data fit into a model in which Cdc14 binds and inhibits Swe1 to allow timely mitotic spindle elongation.
authors.affiliation: From the Dipartimento di Biotecnologie e Bioscienze, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy and.
authors.forename: Erica
authors.initials: E
authors.lastname: Raspelli
authors.affiliation: From the Dipartimento di Biotecnologie e Bioscienze, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy and.
authors.forename: Corinne
authors.initials: C
authors.lastname: Cassani
authors.affiliation: the IFOM, the FIRC (Fondazione Italiana per la Ricerca sul Cancro) Institute of Molecular Oncology, 20139 Milano, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Chiroli
authors.affiliation: From the Dipartimento di Biotecnologie e Bioscienze, Università degli Studi di Milano-Bicocca, 20126 Milano, Italy and roberta.fraschini@unimib.it.
authors.forename: Roberta
authors.initials: R
authors.lastname: Fraschini
mesh_terms: D016203:CDC2 Protein Kinase / Q000235:genetics / Q000378:metabolism; D017489:CDC28 Protein Kinase, S cerevisiae / Q000235:genetics / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000235:genetics* / Q000378:metabolism; D020090:Chromosome Segregation; D015966:Gene Expression Regulation, Fungal; D008938:Mitosis; D010766:Phosphorylation; D011485:Protein Binding; D017027:Protein Tyrosine Phosphatases / Q000235:genetics* / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000235:genetics* / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism / Q000648:ultrastructure; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction; D008941:Spindle Apparatus / Q000235:genetics* / Q000378:metabolism / Q000648:ultrastructure; D059008:Time-Lapse Imaging
chemical_list: C074860:CDC14 protein, S cerevisiae; D018797:Cell Cycle Proteins; D029701:Saccharomyces cerevisiae Proteins; C099685:SWE1 protein, S cerevisiae; D011505:Protein-Tyrosine Kinases; D016203:CDC2 Protein Kinase; D017489:CDC28 Protein Kinase, S cerevisiae; D017027:Protein Tyrosine Phosphatases
keywords: Cyclin-dependent Kinase (Cdk); Mitosis; Mitotic Spindle; Phosphorylation; Yeast