title: Characterization of the Atg17-Atg29-Atg31 complex specifically required for starvation-induced autophagy in Saccharomyces cerevisiae.
abstract: Nutrient starvation induces autophagy to degrade cytoplasmic materials in the vacuole/lysosomes. In the yeast, Saccharomyces cerevisiae, Atg17, Atg29, and Atg31/Cis1 are specifically required for autophagosome formation by acting as a scaffold complex essential for pre-autophagosomal structure (PAS) organization. Here, we show that these proteins constitutively form an Atg17-Atg29-Atg31 ternary complex, in which phosphorylated Atg31 is included. Reconstitution analysis of the ternary complex in E. coli indicates that the three proteins are included in equimolar amounts in the complex. The molecular mass of a monomeric Atg17-Atg29-Atg31 complex is calculated at 97kDa; however, analytical ultracentrifugation shows that the molecular mass of the ternary complex is 198kDa, suggesting a dimeric complex. We propose that this ternary complex acts as a functional unit for autophagosome formation.
authors.affiliation: Advanced Research Organization, Integrated Research Institute, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Japan.
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Kabeya
authors.forename: Nobuo N
authors.initials: NN
authors.lastname: Noda
authors.forename: Yuko
authors.initials: Y
authors.lastname: Fujioka
authors.forename: Kuninori
authors.initials: K
authors.lastname: Suzuki
authors.forename: Fuyuhiko
authors.initials: F
authors.lastname: Inagaki
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Ohsumi
mesh_terms: D001343:Autophagy; D000071183:Autophagy-Related Proteins; D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism*; D003600:Cytosol / Q000378:metabolism; D010588:Phagosomes / Q000378:metabolism*; D010750:Phosphoproteins / Q000737:chemistry / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000378:metabolism*; D014461:Ultracentrifugation
chemical_list: C506770:ATG29 protein, S cerevisiae; C505602:Atg17 protein, S cerevisiae; C520043:Atg31 protein, S cerevisiae; D000071183:Autophagy-Related Proteins; D002352:Carrier Proteins; D010750:Phosphoproteins; D029701:Saccharomyces cerevisiae Proteins