Identification and functional characterization of yeast zeta-COP.
Coatomer, the cytosolic protein complex, consists of seven subunits (alpha-, beta-, beta'-, gamma-, delta-, epsilon-, and zeta-COP) and is involved in vesicle trafficking early in the secretory pathway in collaboration with a 20 kDa GTP-binding protein (ARF). In the present study, we have identified a yeast gene which encodes a protein having 39% amino acid sequence identity with bovine zeta-COP. This gene (YZC1 for Yeast Zeta COP) is essential for vegetative growth and the growth defect of delta yzc1 cells was restored by bovine zeta-COP cDNA. We isolated a temperature-sensitive mutant of YZC1 (yzc1ts) and examined its capacity for both the ER-to-Golgi transport and the double lysine motif (KKXX)-mediated retrograde transport from Golgi to ER. At non-permissive temperature, the yzc1ts cells exhibited a weak defect in the anterograde transport, but a strong defect in the retrograde vesicle transport. We conclude that Yzc1p is a yeast homologue of mammalian zeta-COP and participates mainly in the Golgi-to-ER retrograde transport.
Yamazaki
S
S
Department of Molecular Biology, Graduate School of Medical Science, Kyushu University, Fukuoka.
Harashima
S
S
Sakaguchi
M
M
Mihara
K
K
D000595:Amino Acid Sequence; D000818:Animals; D001692:Biological Transport; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D002417:Cattle; D020756:Coatomer Protein; D004721:Endoplasmic Reticulum / Q000235:genetics / Q000378:metabolism; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D005800:Genes, Fungal; D005816:Genetic Complementation Test; D006056:Golgi Apparatus / Q000378:metabolism; D000072235:Mating Factor; D008969:Molecular Sequence Data; D009154:Mutation; D010455:Peptides / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D011233:Precipitin Tests; D011817:Rabbits; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000254:growth & development; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D013696:Temperature; D015003:Yeasts / Q000235:genetics* / Q000254:growth & development
D002352:Carrier Proteins; D020756:Coatomer Protein; D005656:Fungal Proteins; D010455:Peptides; C105719:RET3 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D000072235:Mating Factor