Loss of a GPI-anchored membrane protein Aah3p causes a defect in vacuolar protein sorting in Schizosaccharomyces pombe.
Schizosaccharomyces pombe has four alpha-amylase homologs (Aah1p-Aah4p) with a glycosylphosphatidylinositol (GPI) modification site at the C-terminal end. Disruption mutants of aah genes were tested for mislocalization of vacuolar carboxypeptidase Y (CPY), and aah3Delta was found to secrete CPY. The conversion rate from pro- to mature CPY was greatly impaired in aah3Delta, and fluorescence microscopy inidicated that a sorting receptor for CPY, Vps10p, mislocalized to the vacuolar membrane. These results indicate that aah3Delta had a defect in the retrograde transport of Vps10p, and that Aah3p is the first S. pombe specific protein required for vacuolar protein sorting.
Iwaki
Tomoko
T
Department of Life Sciences, Faculty of Agriculture, Kagawa University, Miki-cho, Kagawa, Japan.
Morita
Tomotake
T
Tanaka
Naotaka
N
Giga-Hama
Yuko
Y
Takegawa
Kaoru
K
D043402:Cathepsin A / Q000378:metabolism; D005453:Fluorescence; D017261:Glycosylphosphatidylinositols / Q000235:genetics / Q000502:physiology*; D008565:Membrane Proteins / Q000235:genetics / Q000502:physiology*; D008856:Microscopy, Fluorescence; D009154:Mutation / Q000502:physiology; D010957:Plasmids / Q000235:genetics; D012568:Schizosaccharomyces / Q000235:genetics / Q000378:metabolism*; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D014617:Vacuoles / Q000235:genetics / Q000378:metabolism*; D000516:alpha-Amylases / Q000235:genetics / Q000378:metabolism / Q000502:physiology*
D017261:Glycosylphosphatidylinositols; D008565:Membrane Proteins; D029702:Schizosaccharomyces pombe Proteins; C512935:AAH3 protein, S pombe; D000516:alpha-Amylases; D043402:Cathepsin A