Yeast Mon1p/Aut12p functions in vacuolar fusion of autophagosomes and cvt-vesicles.
Here we identify Mon1p as being essential for the cvt-pathway and autophagy. Thus, mon1Delta cells are impaired in proaminopeptidase I maturation and homozygous diploid mon1Delta cells do not sporulate. Quantitative autophagy measurements suggest a complete autophagy block. The autophagosomal marker protein GFP-Aut7p accumulates in mon1Delta cells at punctate structures outside the vacuole. Furthermore, proaminopeptidase I accumulates in mon1Delta cells in a proteinase-protected form. Our data demonstrate that mon1Delta cells are defective in the fusion of cvt-vesicles and autophagosomes with the vacuole. Consistent with this, GFP-Mon1p localizes to the cytosol and to punctate structures within the cytosol.
Meiling-Wesse
Khuyen
K
Institute of Biochemistry, University of Stuttgart, Pfaffenwaldring 55, Germany.
Barth
Henning
H
Voss
Christiane
C
Barmark
Gunilla
G
Murén
Eva
E
Ronne
Hans
H
Thumm
Michael
M
D000626:Aminopeptidases / Q000378:metabolism; D001343:Autophagy; D001483:Base Sequence; D017931:DNA Primers; D005656:Fungal Proteins / Q000378:metabolism*; D010588:Phagosomes / Q000201:enzymology / Q000502:physiology*; D011498:Protein Precursors / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000378:metabolism*; D014617:Vacuoles / Q000201:enzymology / Q000502:physiology*
D017931:DNA Primers; D005656:Fungal Proteins; D011498:Protein Precursors; D000626:Aminopeptidases; C450422:proaminopeptidase I