Endocytosis in yeast: evidence for the involvement of a small GTP-binding protein (Ypt7p).
From the budding yeast S. cerevisiae, we have cloned a gene, YPT7, that encodes a GTP-binding protein belonging to the Ypt family of ras-related proteins. The 208 amino acid protein shares identical effector domain and C-terminal sequences with the mammalian Rab7 protein. YPT7 gene disruption did not impair cellular growth at temperatures ranging from 17 degrees C to 37 degrees C. ypt7 null mutants are characterized by highly fragmented vacuoles and differential defects of vacuolar protein transport and maturation. The uptake of alpha factor pheromone by wild-type and Ypt7p-deficient cells was found to be indistinguishable, but in mutant cells lacking Ypt7p, degradation of the endocytosed pheromone was severely inhibited. Our findings suggest a role of Ypt7p in protein transport between endosome-like compartments.
Wichmann
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H
Max Planck Institute for Biophysical Chemistry, Department of Molecular Genetics, Germany.
Hengst
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Gallwitz
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D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001692:Biological Transport; D004252:DNA Mutational Analysis; D004705:Endocytosis; D019204:GTP-Binding Proteins / Q000235:genetics*; D011905:Genes, ras; D008969:Molecular Sequence Data; D011506:Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid; D014617:Vacuoles / Q000378:metabolism; D020691:rab GTP-Binding Proteins
D011506:Proteins; D029701:Saccharomyces cerevisiae Proteins; D019204:GTP-Binding Proteins; C079005:YPT7 protein, S cerevisiae; D020691:rab GTP-Binding Proteins