Role of Vac8 in formation of the vacuolar sequestering membrane during micropexophagy.
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.
Oku
Masahide
M
Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kitashirakawa-Oiwake, Sakyo-ku, Kyoto, Japan.
Nishimura
Taku
T
Hattori
Takeshi
T
Ano
Yoshitaka
Y
Yamashita
Shun-ichi
S
Sakai
Yasuyoshi
Y
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
D005656:Fungal Proteins; D008074:Lipoproteins; D008565:Membrane Proteins; D011993:Recombinant Fusion Proteins; D033921:Vesicular Transport Proteins; D000429:Alcohol Oxidoreductases; C019643:alcohol oxidase