Aut2p and Aut7p, two novel microtubule-associated proteins are essential for delivery of autophagic vesicles to the vacuole.
AUT2 and AUT7, two novel genes essential for autophagocytosis in the yeast Saccharomyces cerevisiae were isolated. AUT7 was identified as a low copy suppressor of autophagic defects in aut2-1 cells. Aut7p is a homologue of the rat microtubule-associated protein (MAP) light chain 3 (LC3). Aut2p and Aut7p interact physically. Aut7p is attached to microtubules via Aut2p, which interacts with tubulins Tub1p and Tub2p. aut2- and aut7-deleted cells are unable to deliver autophagic vesicles and the precursor of aminopeptidase I to the vacuole. Double membrane-layered autophagosome-like vesicles accumulate in the cytoplasm of these cells. Our findings suggest that microtubules and an attached protein complex of Aut2p and Aut7p are involved in the delivery of autophagic vesicles to the vacuole.
Lang
T
T
Universität Stuttgart, Institut für Biochemie, Pfaffenwaldring 55, 70569 Stuttgart, Germany.
Schaeffeler
E
E
Bernreuther
D
D
Bredschneider
M
M
Wolf
D H
DH
Thumm
M
M
D000595:Amino Acid Sequence; D000818:Animals; D001343:Autophagy / Q000502:physiology*; D000071190:Autophagy-Related Protein 8 Family; D000071183:Autophagy-Related Proteins; D001483:Base Sequence; D003546:Cysteine Endopeptidases; D004271:DNA, Fungal; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D005800:Genes, Fungal; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D010588:Phagosomes; D010641:Phenotype; D051381:Rats; D012441:Saccharomyces cerevisiae / Q000254:growth & development / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid; D014617:Vacuoles / Q000378:metabolism
C113757:ATG8 protein, S cerevisiae; C113755:Atg4 protein, S cerevisiae; D000071190:Autophagy-Related Protein 8 Family; D000071183:Autophagy-Related Proteins; D004271:DNA, Fungal; D005656:Fungal Proteins; D008869:Microtubule-Associated Proteins; D029701:Saccharomyces cerevisiae Proteins; D003546:Cysteine Endopeptidases