title: The DNA damage checkpoint regulates a transition between yeast and hyphal growth in Schizosaccharomyces japonicus.
abstract: Dimorphic yeasts change between unicellular growth and filamentous growth. Many dimorphic yeasts species are pathogenic for humans and plants, being infectious as invasive hypha. We have studied the determinants of the dimorphic switch in the nonpathogenic fission yeast Schizosaccharomyces japonicus, which is evolutionarily close to the well-characterized fission yeast S. pombe. We report that camptothecin, an inhibitor of topoisomerase I, reversibly induced the unicellular to hyphal transition in S. japonicus at low concentrations of camptothecin that did not induce checkpoint arrest and the transition required the DNA checkpoint kinase Chk1. Furthermore, a mutation of chk1 induced hyphal transition without camptothecin. Thus, we identify a second function for Chk1 distinct from its role in checkpoint arrest. Activation of the switch from single cell bipolar growth to monopolar filamentous growth may assist cells to evade the source of DNA damage.
authors.affiliation: Department of Genetics, Graduate University for Advanced Studies (Sokendai), Shizuoka, Japan.
authors.forename: Kanji
authors.initials: K
authors.lastname: Furuya
authors.forename: Hironori
authors.initials: H
authors.lastname: Niki
mesh_terms: D000595:Amino Acid Sequence; D002166:Camptothecin / Q000494:pharmacology; D002453:Cell Cycle / Q000187:drug effects; D000071877:Checkpoint Kinase 1; D004249:DNA Damage / Q000187:drug effects; D004789:Enzyme Activation / Q000187:drug effects; D005800:Genes, Fungal / Q000235:genetics; D025301:Hyphae / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology / Q000254:growth & development*; D008954:Models, Biological; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D011494:Protein Kinases / Q000737:chemistry / Q000235:genetics; D012568:Schizosaccharomyces / Q000166:cytology* / Q000201:enzymology / Q000235:genetics / Q000254:growth & development*; D029702:Schizosaccharomyces pombe Proteins; D013312:Stress, Physiological / Q000187:drug effects
chemical_list: D029702:Schizosaccharomyces pombe Proteins; D011494:Protein Kinases; C000605867:CHEK1 protein, human; D000071877:Checkpoint Kinase 1; C000605873:Chk1 protein, S pombe; D002166:Camptothecin