title: Phosphorylation-dependent regulation of the F-BAR protein Hof1 during cytokinesis.
abstract: Spatial and timely coordination of cytokinesis is crucial for the maintenance of organelle inheritance and genome integrity. The mitotic exit network (MEN) pathway controls both the timely initiation of mitotic exit and cytokinesis in budding yeast. Here we identified the conserved F-BAR protein Hof1 as a substrate of the MEN kinase complex Dbf2-Mob1 during cytokinesis. We show that polo-like kinase Cdc5 first phosphorylates Hof1 to allow subsequent phosphorylation by Dbf2-Mob1. This releases Hof1 from the septin ring and facilitates Hof1 binding to the medial actomyosin ring (AMR), where Hof1 promotes AMR contraction and membrane ingression. Domain structure analysis established that the central, unstructured, region of Hof1, named the ring localization sequence (RLS), is sufficient to mediate Hof1's binding to the medial ring in a cell cycle-dependent manner. Genetic and functional data support a model in which Dbf2-Mob1 regulates Hof1 by inducing domain rearrangements, leading to the exposure of the Hof1 RLS domain during telophase.
authors.affiliation: Molecular Biology of Centrosomes and Cilia Unit, DKFZ-ZMBH Alliance, German Cancer Research Center, 69120 Heidelberg, Germany.
authors.forename: Franz
authors.initials: F
authors.lastname: Meitinger
authors.forename: Martin E
authors.initials: ME
authors.lastname: Boehm
authors.forename: Astrid
authors.initials: A
authors.lastname: Hofmann
authors.forename: Birgit
authors.initials: B
authors.lastname: Hub
authors.forename: Hanswalter
authors.initials: H
authors.lastname: Zentgraf
authors.forename: Wolf D
authors.initials: WD
authors.lastname: Lehmann
authors.forename: Gislene
authors.initials: G
authors.lastname: Pereira
mesh_terms: D015153:Blotting, Western; D002453:Cell Cycle / Q000235:genetics / Q000502:physiology; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D048749:Cytokinesis / Q000235:genetics / Q000502:physiology*; D047468:Immunoprecipitation; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism*; D008938:Mitosis / Q000235:genetics / Q000502:physiology; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D018797:Cell Cycle Proteins; C116847:HOF1 protein, S cerevisiae; C110689:MOB1 protein, S cerevisiae; D008869:Microtubule-Associated Proteins; D010750:Phosphoproteins; D029701:Saccharomyces cerevisiae Proteins; D011494:Protein Kinases; C085768:DBF2 protein, S cerevisiae; D017346:Protein Serine-Threonine Kinases; C081927:CDC5 protein, S cerevisiae