Ccz1p/Aut11p/Cvt16p is essential for autophagy and the cvt pathway.
In a reverse genetics screen, we here identify Ccz1p as an essential component of the cvt pathway and autophagy. Ccz1p is identical with the so far unknown Cvt16p. GFP-Aut7p, a specific cargo of autophagosomes, accumulates in ccz1 Delta cells at punctate, vesicular structures in the cytosol, suggesting a block in the autophagic pathway prior to vacuolar fusion of autophagosomes. Proteinase protection experiments using hypotonically lysed ccz1 Delta spheroplasts demonstrate that proaminopeptidase I, another specific cargo of autophagy and the cvt pathway, is trapped inside membrane-enclosed vesicles. Taken together our findings are compatible with a function of Ccz1p in vacuolar fusion of cvt vesicles and autophagosomes.
Meiling-Wesse
Khuyen
K
University of Stuttgart, Institute of Biochemistry, Pfaffenwaldring 55, 70569 Stuttgart, Germany.
Barth
Henning
H
Thumm
Michael
M
D000071183:Autophagy-Related Proteins; D002352:Carrier Proteins; D049452:Green Fluorescent Proteins; D020662:Guanine Nucleotide Exchange Factors; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D016296:Mutagenesis; D011994:Recombinant Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*; D044763:Ubiquitin-Conjugating Enzymes; D033921:Vesicular Transport Proteins
D000071183:Autophagy-Related Proteins; D002352:Carrier Proteins; C441960:Ccz1 protein, S cerevisiae; D020662:Guanine Nucleotide Exchange Factors; D008164:Luminescent Proteins; D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins; D033921:Vesicular Transport Proteins; D049452:Green Fluorescent Proteins; D044763:Ubiquitin-Conjugating Enzymes; C104235:ATG3 protein, S cerevisiae