title: Endocytosis is essential for dynamic translocation of a syntaxin 1 orthologue during fission yeast meiosis.
abstract: Syntaxin is a component of the target soluble N-ethylmaleimide-sensitive factor attachment protein receptor complex, which is responsible for fusion of membrane vesicles at the target membrane. The fission yeast syntaxin 1 orthologue Psy1 is essential for both vegetative growth and spore formation. During meiosis, Psy1 disappears from the plasma membrane (PM) and dramatically relocalizes on the nascent forespore membrane, which becomes the PM of the spore. Here we report the molecular details and biological significance of Psy1 relocalization. We find that, immediately after meiosis I, Psy1 is selectively internalized by endocytosis. In addition, a meiosis-specific signal induced by the transcription factor Mei4 seems to trigger this internalization. The internalization of many PM proteins is facilitated coincident with the initiation of meiosis, whereas Pma1, a P-type ATPase, persists on the PM even during the progression of meiosis II. Ergosterol on the PM is also important for the internalization of PM proteins in general during meiosis. We consider that during meiosis in Schizosaccharomyces pombe cells, the characteristics of endocytosis change, thereby facilitating internalization of Psy1 and accomplishing sporulation.
authors.affiliation: Department of Biology, Graduate School of Science, Osaka City University, Osaka 558-8585, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Kashiwazaki
authors.forename: Yuriko
authors.initials: Y
authors.lastname: Yamasaki
authors.forename: Akiko
authors.initials: A
authors.lastname: Itadani
authors.forename: Erika
authors.initials: E
authors.lastname: Teraguchi
authors.forename: Yukari
authors.initials: Y
authors.lastname: Maeda
authors.forename: Chikashi
authors.initials: C
authors.lastname: Shimoda
authors.forename: Taro
authors.initials: T
authors.lastname: Nakamura
mesh_terms: D002462:Cell Membrane / Q000378:metabolism; D004705:Endocytosis / Q000235:genetics*; D015966:Gene Expression Regulation, Fungal; D008540:Meiosis / Q000235:genetics*; D009154:Mutation; D021381:Protein Transport; D050765:Qa-SNARE Proteins / Q000235:genetics / Q000378:metabolism*; D012568:Schizosaccharomyces / Q000235:genetics / Q000254:growth & development*; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics / Q000378:metabolism*; D008941:Spindle Apparatus / Q000235:genetics / Q000378:metabolism; D013172:Spores, Fungal / Q000235:genetics / Q000378:metabolism
chemical_list: C510389:Psy1 protein, S pombe; D050765:Qa-SNARE Proteins; D029702:Schizosaccharomyces pombe Proteins; C489539:mei4 protein, S pombe