Use1p is a yeast SNARE protein required for retrograde traffic to the ER.
SNAREs on transport vesicles and target membranes are required for vesicle targeting and fusion. Here we describe a novel yeast protein with a typical SNARE motif but with low overall amino acid homologies to other SNAREs. The protein localized to the endoplasmic reticulum (ER) and was therefore named Use1p (unconventional SNARE in the ER). A temperature-sensitive use1 mutant was generated. use1 mutant cells accumulated the ER forms of carboxypeptidase Y and invertase. More specific assays revealed that use1 mutant cells were defective in retrograde traffic to the ER. This was supported by strong genetic interactions between USE1 and the genes encoding SNAREs in retrograde traffic to the ER. Antibodies directed against Use1p co-immunoprecipitated the SNAREs Ufe1p, myc-Sec20p and Sec22p, which form a SNARE complex required for retrograde traffic from the Golgi to the ER, but neither Bos1p nor Bet1p (members of the SNARE complex in anterograde traffic to the Golgi). Therefore, we conclude that Use1p is a novel SNARE protein that functions in retrograde traffic from the Golgi to the ER.
Dilcher
Meik
M
Abteilung Biochemie II, Universität Göttingen, Heinrich-Düker Weg 12, D-37073 Göttingen, Germany.
Veith
Beate
B
Chidambaram
Subbulakshmi
S
Hartmann
Enno
E
Schmitt
Hans Dieter
HD
Fischer von Mollard
Gabriele
G
D000483:Alleles; D000595:Amino Acid Sequence; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D005800:Genes, Fungal; D005804:Genes, Lethal; D006056:Golgi Apparatus / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D017434:Protein Structure, Tertiary; D021122:Protein Subunits / Q000737:chemistry / Q000378:metabolism; D050767:Qc-SNARE Proteins; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D050600:SNARE Proteins; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid; D013489:Suppression, Genetic; D013696:Temperature; D013997:Time Factors; D033921:Vesicular Transport Proteins; D015003:Yeasts / Q000235:genetics / Q000378:metabolism*
D005656:Fungal Proteins; D008565:Membrane Proteins; D021122:Protein Subunits; D050767:Qc-SNARE Proteins; D011993:Recombinant Fusion Proteins; D050600:SNARE Proteins; D029701:Saccharomyces cerevisiae Proteins; C477343:Use1 protein, S cerevisiae; D033921:Vesicular Transport Proteins