title: Budding yeast dma proteins control septin dynamics and the spindle position checkpoint by promoting the recruitment of the Elm1 kinase to the bud neck.
abstract: The first step towards cytokinesis in budding yeast is the assembly of a septin ring at the future site of bud emergence. Integrity of this ring is crucial for cytokinesis, proper spindle positioning, and the spindle position checkpoint (SPOC). This checkpoint delays mitotic exit and cytokinesis as long as the anaphase spindle does not properly align with the division axis. SPOC signalling requires the Kin4 protein kinase and the Kin4-regulating Elm1 kinase, which also controls septin dynamics. Here, we show that the two redundant ubiquitin-ligases Dma1 and Dma2 control septin dynamics and the SPOC by promoting the efficient recruitment of Elm1 to the bud neck. Indeed, dma1 dma2 mutant cells show reduced levels of Elm1 at the bud neck and Elm1-dependent activation of Kin4. Artificial recruitment of Elm1 to the bud neck of the same cells is sufficient to re-establish a normal septin ring, proper spindle positioning, and a proficient SPOC response in dma1 dma2 cells. Altogether, our data indicate that septin dynamics and SPOC function are intimately linked and support the idea that integrity of the bud neck is crucial for SPOC signalling.
authors.affiliation: Dipartimento di Biotecnologie e Bioscienze, Università di Milano-Bicocca, Milano, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Merlini
authors.forename: Roberta
authors.initials: R
authors.lastname: Fraschini
authors.forename: Barbara
authors.initials: B
authors.lastname: Boettcher
authors.forename: Yves
authors.initials: Y
authors.lastname: Barral
authors.forename: Giovanna
authors.initials: G
authors.lastname: Lucchini
authors.forename: Simonetta
authors.initials: S
authors.lastname: Piatti
mesh_terms: D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D048749:Cytokinesis / Q000235:genetics; D015966:Gene Expression Regulation, Fungal; D059566:M Phase Cell Cycle Checkpoints / Q000235:genetics; D008938:Mitosis; D009154:Mutation; D010766:Phosphorylation; D011494:Protein Kinases / Q000235:genetics* / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000254:growth & development; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism*; D058112:Septins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D018797:Cell Cycle Proteins; C493793:DMA2 protein, S cerevisiae; C493792:Dma1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D011494:Protein Kinases; C411302:ELM1 protein, S cerevisiae; C503719:KIN4 kinase, S cerevisiae; D017346:Protein Serine-Threonine Kinases; D058112:Septins