title: Role of Vac8 in formation of the vacuolar sequestering membrane during micropexophagy.
abstract: Vac8 is a yeast vacuolar membrane protein involved in vacuolar membrane dynamics, e.g., vacuole inheritance and vacuolar membrane fusion. This protein is also necessary for a subset of autophagic pathways that deliver specific cellular components to the vacuole. In this study, we show that the micropexohagy and vacuole inheritance required distinct domain structures of Pichia pastoris Vac8 (PpVac8). Whereas vacuole inheritance required the Armadillo repeat (ARM) region that resides in the middle part of the protein, micropexophagy did not. Deletion of both the ARM and C-terminal domains inhibited a characteristic of vacuolar dynamics during micropexophagy, i.e., formation of the vacuolar sequestering membrane (VSM). Subsequent analyses indicated that PpVAC8 disruption abolished recruitment of PpAtg11, another protein required for formation of the VSM, to the vacuolar membrane. These results present a novel molecular function of PpVac8 in micropexophagy.
authors.affiliation: Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kitashirakawa-Oiwake, Sakyo-ku, Kyoto, Japan.
authors.forename: Masahide
authors.initials: M
authors.lastname: Oku
authors.forename: Taku
authors.initials: T
authors.lastname: Nishimura
authors.forename: Takeshi
authors.initials: T
authors.lastname: Hattori
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Ano
authors.forename: Shun-ichi
authors.initials: S
authors.lastname: Yamashita
authors.forename: Yasuyoshi
authors.initials: Y
authors.lastname: Sakai
mesh_terms: D000429:Alcohol Oxidoreductases / Q000378:metabolism; D020816:Amino Acid Motifs; D001343:Autophagy / Q000502:physiology*; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D007425:Intracellular Membranes / Q000378:metabolism*; D008074:Lipoproteins / Q000235:genetics / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D010843:Pichia / Q000166:cytology / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D014617:Vacuoles / Q000378:metabolism*; D033921:Vesicular Transport Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D005656:Fungal Proteins; D008074:Lipoproteins; D008565:Membrane Proteins; D011993:Recombinant Fusion Proteins; D033921:Vesicular Transport Proteins; D000429:Alcohol Oxidoreductases; C019643:alcohol oxidase