Characterization of yeast sar1 temperature-sensitive mutants, which are defective in protein transport from the endoplasmic reticulum.
SAR1 encodes a low molecular weight GTPase that is essential in the early process of vesicular transport in the secretory pathway. By random and site-directed mutagenesis of the SAR1 gene, we have obtained three temperature-sensitive mutants, N132I, E112K, and D32G. They all show a defect in transport from the endoplasmic reticulum to the Golgi apparatus, and accumulate endoplasmic reticulum membranes at the restrictive temperature. This is consistent with our previous observations in vivo on a galactose-shutoff mutant as well as the in vitro results, and provides powerful tools for further genetic analyses.
Department of Biological Sciences, Graduate School of Science, University of Tokyo.
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Yamanushi
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Hirata
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Oka
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Nakano
D000483:Alleles; D000595:Amino Acid Sequence; D001693:Biological Transport, Active; D004721:Endoplasmic Reticulum / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics; D005656:Fungal Proteins / Q000378:metabolism; D019204:GTP-Binding Proteins / Q000235:genetics* / Q000378:metabolism*; D005800:Genes, Fungal; D006056:Golgi Apparatus / Q000378:metabolism; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D020559:Monomeric GTP-Binding Proteins; D016296:Mutagenesis; D009154:Mutation; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism* / Q000648:ultrastructure; D029701:Saccharomyces cerevisiae Proteins; D013696:Temperature; D033921:Vesicular Transport Proteins
D005656:Fungal Proteins; D029701:Saccharomyces cerevisiae Proteins; D033921:Vesicular Transport Proteins; D019204:GTP-Binding Proteins; D020559:Monomeric GTP-Binding Proteins; C077395:SAR1 protein, S cerevisiae