title: N-glycans are not required for the efficient degradation of the mutant Saccharomyces cerevisiae CPY* in Schizosaccharomyces pombe.
abstract: In eukaryotic cells, aberrant proteins generated in the endoplasmic reticulum (ER) are degraded by the ER-associated degradation (ERAD) pathway. Here, we report on the ERAD pathway of the fission yeast Schizosaccharomyces pombe. We constructed and expressed Saccharomyces cerevisiae wild-type CPY (ScCPY) and CPY-G255R mutant (ScCPY*) in S. pombe. While ScCPY was glycosylated and efficiently transported to the vacuoles in S. pombe, ScCPY* was retained in the ER and was not processed to the matured form in these cells. Cycloheximide chase experiments revealed that ScCPY* was rapidly degraded in S. pombe, and its degradation depended on Hrd1p and Ubc7p homologs. We also found that Mnl1p and Yos9p, proteins that are essential for ERAD in S. cerevisiae, were not required for ScCPY* degradation in S. pombe. Moreover, the null-glycosylation mutant of ScCPY, CPY*0000, was rapidly degraded by the ERAD pathway. These results suggested that N-linked oligosaccharides are not important for the recognition of luminal proteins for ERAD in S. pombe cells.
authors.affiliation: ASPEX Division, Research Center, Asahi Glass Co., Ltd, 1150 Hazawa-cho, Kanagawa, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Mukaiyama
authors.forename: Michiko
authors.initials: M
authors.lastname: Kodera
authors.forename: Naotaka
authors.initials: N
authors.lastname: Tanaka
authors.forename: Kaoru
authors.initials: K
authors.lastname: Takegawa
mesh_terms: D019943:Amino Acid Substitution; D002268:Carboxypeptidases / Q000235:genetics* / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000378:metabolism; D050505:Mutant Proteins / Q000235:genetics / Q000378:metabolism; D020125:Mutation, Missense; D011134:Polysaccharides / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D059748:Proteolysis; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism*; D012568:Schizosaccharomyces / Q000235:genetics* / Q000378:metabolism*; D029702:Schizosaccharomyces pombe Proteins / Q000378:metabolism; D044763:Ubiquitin-Conjugating Enzymes / Q000378:metabolism; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism
chemical_list: D050505:Mutant Proteins; D011134:Polysaccharides; D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins; D029702:Schizosaccharomyces pombe Proteins; C544200:Ubc7 protein, S pombe; D044763:Ubiquitin-Conjugating Enzymes; C544201:Hrd1 protein, S pombe; D044767:Ubiquitin-Protein Ligases; D002268:Carboxypeptidases; C520242:CPY protein, S cerevisiae