title: Mob2p interacts with the protein kinase Orb6p to promote coordination of cell polarity with cell cycle progression.
abstract: The molecular mechanisms that temporally and spatially coordinate cell morphogenesis with the cell cycle remain poorly understood. Here we describe the characterization of fission yeast Mob2p, a novel protein required for regulating cell polarity and cell cycle control. Deletion of mob2 is lethal and causes cells to become spherical, with depolarized actin and microtubule cytoskeletons. A decrease in Mob2p protein level results in a defect in the activation of bipolar growth. This phenotype is identical to that of mutants defective in the orb6 protein kinase gene, and we find that Mob2p physically interacts with Orb6p. In addition, overexpression of Mob2p, like that of Orb6p, results in a delay in the onset of mitosis. Mob2p localizes to the cell periphery and cytoplasm throughout the cell cycle and to the division site during late anaphase and telophase. Mob2p is unable to localize to the cell middle in mutants defective in actomyosin ring and septum formation. Our results suggest that Mob2p, along with Orb6p, is required for coordinating polarized cell growth during interphase with the onset of mitosis.
authors.affiliation: Department of Molecular Genetics and Microbiology, University of Massachusetts Medical School, Worcester, MA 01605, USA.
authors.forename: Ming-Chin
authors.initials: MC
authors.lastname: Hou
authors.forename: David J
authors.initials: DJ
authors.lastname: Wiley
authors.forename: Fulvia
authors.initials: F
authors.lastname: Verde
authors.forename: Dannel
authors.initials: D
authors.lastname: McCollum
mesh_terms: D000199:Actins / Q000235:genetics / Q000378:metabolism; D002453:Cell Cycle / Q000235:genetics*; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D016764:Cell Polarity / Q000235:genetics*; D002478:Cells, Cultured; D003599:Cytoskeleton / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D005804:Genes, Lethal / Q000235:genetics; D008938:Mitosis / Q000235:genetics; D009154:Mutation / Q000235:genetics; D009218:Myosins / Q000235:genetics / Q000378:metabolism; D010750:Phosphoproteins / Q000172:deficiency* / Q000235:genetics; D017346:Protein Serine-Threonine Kinases / Q000172:deficiency* / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics; D012568:Schizosaccharomyces / Q000235:genetics / Q000378:metabolism*; D029702:Schizosaccharomyces pombe Proteins
chemical_list: D000199:Actins; D018797:Cell Cycle Proteins; C444039:MOB2 protein, S cerevisiae; D010750:Phosphoproteins; D029701:Saccharomyces cerevisiae Proteins; D029702:Schizosaccharomyces pombe Proteins; C113424:Orb6 protein, S pombe; D017346:Protein Serine-Threonine Kinases; D009218:Myosins