title: Fission yeast Scp3 potentially maintains microtubule orientation through bundling.
abstract: Microtubules play important roles in organelle transport, the maintenance of cell polarity and chromosome segregation and generally form bundles during these processes. The fission yeast gene scp3+ was identified as a multicopy suppressor of the cps3-81 mutant, which is hypersensitive to isopropyl N-3-chlorophenylcarbamate (CIPC), a poison that induces abnormal multipolar spindle formation in higher eukaryotes. In this study, we investigated the function of Scp3 along with the effect of CIPC in the fission yeast Schizosaccharomyces pombe. Microscopic observation revealed that treatment with CIPC, cps3-81 mutation and scp3+ gene deletion disturbed the orientation of microtubules in interphase cells. Overexpression of scp3+ suppressed the abnormal orientation of microtubules by promoting bundling. Functional analysis suggested that Scp3 functions independently from Ase1, a protein largely required for the bundling of the mitotic spindle. A strain lacking the ase1+ gene was more sensitive to CIPC, with the drug affecting the integrity of the mitotic spindle, indicating that CIPC has a mitotic target that has a role redundant with Ase1. These results suggested that multiple systems are independently involved to ensure microtubule orientation by bundling in fission yeast.
authors.affiliation: Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto, Japan.
authors.forename: Kanako
authors.initials: K
authors.lastname: Ozaki
authors.affiliation: Advanced ICT Research Institute Kobe, National Institute of Information and Communications Technology, Kobe, Hyogo, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Chikashige
authors.affiliation: Advanced ICT Research Institute Kobe, National Institute of Information and Communications Technology, Kobe, Hyogo, Japan; Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Hiraoka
authors.affiliation: Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto, Japan; Radiation Biology Center, Kyoto University, Kyoto, Kyoto, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Matsumoto
mesh_terms: D002748:Chlorpropham / Q000633:toxicity; D049452:Green Fluorescent Proteins / Q000378:metabolism; D008856:Microscopy, Fluorescence; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism; D008870:Microtubules / Q000187:drug effects / Q000502:physiology*; D010957:Plasmids / Q000235:genetics; D012568:Schizosaccharomyces; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*
chemical_list: C502827:Ase1 protein, S pombe; D008869:Microtubule-Associated Proteins; D029702:Schizosaccharomyces pombe Proteins; D002748:Chlorpropham; D049452:Green Fluorescent Proteins