Identification and structure of four yeast genes (SLY) that are able to suppress the functional loss of YPT1, a member of the RAS superfamily.
In Saccharomyces cerevisiae, the GTP-binding Ypt1 protein (Ypt1p) is essential for endoplasmic reticulum-to-Golgi protein transport. By exploiting a GAL10-YPT1 fusion to regulate YPT1 expression, three multicopy suppressors, SLY2, SLY12, and SLY41, and a single-copy suppressor, SLY1-20, that allowed YPT1-independent growth were isolated. Wild-type Sly1p is hydrophilic, is essential for cell viability, and differs from Sly1-20p by a single amino acid. SLY2 and SLY12 encode proteins with hydrophobic tails similar to synaptobrevins, integral membrane proteins of synaptic vesicles in higher eucaryotes. Sly41p is hydrophobic and exhibits sequence similarities with the chloroplast phosphate translocator. SLY12 but not SLY41 is an essential gene. The SLY2 null mutant is cold and heat sensitive. The SLY gene products may comprise elements of the protein transport machinery.
Dascher
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Department of Molecular Genetics, Max Planck Institute for Biophysical Chemistry, Göttingen, Federal Republic of Germany.
Ossig
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Gallwitz
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Schmitt
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D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics; D005800:Genes, Fungal; D016153:Genes, Suppressor; D011905:Genes, ras; D005838:Genotype; D008969:Molecular Sequence Data; D005810:Multigene Family; D011487:Protein Conformation; D011506:Proteins / Q000235:genetics* / Q000378:metabolism; D050683:R-SNARE Proteins; D011956:Receptors, Cell Surface; D015183:Restriction Mapping; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D012689:Sequence Homology, Nucleic Acid; D020691:rab GTP-Binding Proteins
D005656:Fungal Proteins; D011506:Proteins; D050683:R-SNARE Proteins; D011956:Receptors, Cell Surface; D029701:Saccharomyces cerevisiae Proteins; C106909:Sec22 protein, S cerevisiae; C060755:YPT1 protein, S cerevisiae; D020691:rab GTP-Binding Proteins