title: Hsp16p is required for thermotolerance in nuclear mRNA export in fission yeast Schizosaccharomyces pombe.
abstract: Export of mRNA from the nucleus to the cytoplasm is one of the essential steps for eukaryotic gene expression. In the fission yeast Schizosaccharomyces pombe, heat shock stress at 42 degrees C causes block of mRNA export from the nucleus. We now report that saline and ethanol stresses also inhibit nuclear mRNA export, resulting in accumulation of bulk poly (A)+ RNA, as well as a specific mRNA, in the nucleus. Under stressed conditions, an mRNA export receptor Mex67p relocates to the nucleolus from the nuclear periphery and this relocation is closely correlated with inhibition of mRNA export by the stresses. Pretreatment of cells with a mild saline stress induced thermotolerance in mRNA export in a similar manner seen with mild heat pretreatment and protected mRNA export machinery from the subsequent severe heat shock. In contrast, mild ethanol stress could not induce the thermotolerance in mRNA export, suggesting that the stress response induced by ethanol differs from that induced by saline and heat shock stresses. In addition, we found that the Spc1p MAPK pathway is involved in induction of thermotolerance in mRNA export. Of the downstream targets for Spc1p, the Atf1p transcription factor was essential for induction of thermotolerance in mRNA export. We also found that Hsp16p, the expression of which is controlled by Atf1p, is involved in acquisition of thermotolerance in mRNA export in S. pombe.
authors.affiliation: Department of Biological Science, Faculty of Science, Kumamoto University, Japan.
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Yoshida
authors.forename: Tokio
authors.initials: T
authors.lastname: Tani
mesh_terms: D021581:Active Transport, Cell Nucleus / Q000187:drug effects / Q000502:physiology*; D002466:Cell Nucleolus / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism*; D000431:Ethanol / Q000494:pharmacology; D006360:Heat-Shock Proteins / Q000502:physiology*; D018869:Heat-Shock Response / Q000502:physiology*; D006358:Hot Temperature; D017404:In Situ Hybridization, Fluorescence; D012333:RNA, Messenger / Q000187:drug effects / Q000378:metabolism*; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism; D012568:Schizosaccharomyces / Q000166:cytology / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics / Q000502:physiology; D012965:Sodium Chloride / Q000494:pharmacology; D014157:Transcription Factors / Q000235:genetics / Q000502:physiology
chemical_list: D006360:Heat-Shock Proteins; D012333:RNA, Messenger; D018160:Receptors, Cytoplasmic and Nuclear; D029702:Schizosaccharomyces pombe Proteins; D014157:Transcription Factors; D000431:Ethanol; D012965:Sodium Chloride