title: The fission yeast spore is coated by a proteinaceous surface layer comprising mainly Isp3.
abstract: The spore is a dormant cell that is resistant to various environmental stresses. As compared with the vegetative cell wall, the spore wall has a more extensive structure that confers resistance on spores. In the fission yeast Schizosaccharomyces pombe, the polysaccharides glucan and chitosan are major components of the spore wall; however, the structure of the spore surface remains unknown. We identify the spore coat protein Isp3/Meu4. The isp3 disruptant is viable and executes meiotic nuclear divisions as efficiently as the wild type, but isp3∆ spores show decreased tolerance to heat, digestive enzymes, and ethanol. Electron microscopy shows that an electron-dense layer is formed at the outermost region of the wild-type spore wall. This layer is not observed in isp3∆ spores. Furthermore, Isp3 is abundantly detected in this layer by immunoelectron microscopy. Thus Isp3 constitutes the spore coat, thereby conferring resistance to various environmental stresses.
authors.affiliation: Department of Biology, Graduate School of Science, Osaka City University, Sumiyoshi-ku, Osaka 558-8585, Japan.
authors.forename: Kana
authors.initials: K
authors.lastname: Fukunishi
authors.affiliation: Department of Biology, Graduate School of Science, Osaka City University, Sumiyoshi-ku, Osaka 558-8585, Japan.
authors.forename: Kana
authors.initials: K
authors.lastname: Miyakubi
authors.affiliation: Department of Biology, Graduate School of Science, Osaka City University, Sumiyoshi-ku, Osaka 558-8585, Japan.
authors.forename: Mitsuko
authors.initials: M
authors.lastname: Hatanaka
authors.affiliation: Department of Biology, Graduate School of Science, Osaka City University, Sumiyoshi-ku, Osaka 558-8585, Japan.
authors.forename: Natsumi
authors.initials: N
authors.lastname: Otsuru
authors.affiliation: Bioimaging Center, Graduate School of Frontier Sciences, University of Tokyo, Kashiwa, Chiba 277-8562, Japan.
authors.forename: Aiko
authors.initials: A
authors.lastname: Hirata
authors.affiliation: Department of Biology, Graduate School of Science, Osaka City University, Sumiyoshi-ku, Osaka 558-8585, Japan.
authors.forename: Chikashi
authors.initials: C
authors.lastname: Shimoda
authors.affiliation: Department of Biology, Graduate School of Science, Osaka City University, Sumiyoshi-ku, Osaka 558-8585, Japan taronaka@sci.osaka-cu.ac.jp.
authors.forename: Taro
authors.initials: T
authors.lastname: Nakamura
mesh_terms: D000581:Amidohydrolases; D000595:Amino Acid Sequence; D002473:Cell Wall / Q000737:chemistry / Q000201:enzymology / Q000235:genetics*; D002686:Chitin / Q000096:biosynthesis; D002687:Chitin Synthase / Q000235:genetics*; D048271:Chitosan / Q000378:metabolism; D000431:Ethanol / Q000633:toxicity; D049452:Green Fluorescent Proteins / Q000235:genetics; D006358:Hot Temperature / Q000009:adverse effects; D008540:Meiosis / Q000235:genetics; D016253:Microscopy, Immunoelectron; D018832:Molecular Chaperones / Q000096:biosynthesis / Q000235:genetics*; D010750:Phosphoproteins / Q000096:biosynthesis / Q000235:genetics*; D059748:Proteolysis; D012568:Schizosaccharomyces / Q000166:cytology*; D029702:Schizosaccharomyces pombe Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D013172:Spores, Fungal / Q000166:cytology*; D013312:Stress, Physiological
chemical_list: C090608:ISP3 protein, S pombe; D018832:Molecular Chaperones; D010750:Phosphoproteins; D029702:Schizosaccharomyces pombe Proteins; C490848:wos2 protein, S pombe; D002686:Chitin; D049452:Green Fluorescent Proteins; D000431:Ethanol; D048271:Chitosan; D002687:Chitin Synthase; D000581:Amidohydrolases; C019866:chitin deacetylase