title: Chaperone selection during glycoprotein translocation into the endoplasmic reticulum.
abstract: A variety of molecular chaperones and folding enzymes assist the folding of newly synthesized proteins in the endoplasmic reticulum. Here we investigated why some glycoproteins interact with the molecular chaperone BiP, and others with the calnexin/calreticulin pathway. The folding of Semliki forest virus glycoproteins and influenza hemagglutinin was studied in living cells. The initial choice of chaperone depended on the location of N-linked glycans in the growing nascent chain. Direct interaction with calnexin and calreticulin without prior interaction with BiP occurred if glycans were present within about 50 residues of the protein's NH2-terminus.
authors.affiliation: Swiss Federal Institute of Technology Zurich (ETHZ), Universitätstrasse 16, CH-8092 Zurich, Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Molinari
authors.forename: A
authors.initials: A
authors.lastname: Helenius
mesh_terms: D000818:Animals; D001665:Binding Sites; D016466:CHO Cells; D002135:Calcium-Binding Proteins / Q000378:metabolism; D037281:Calnexin; D037282:Calreticulin; D002352:Carrier Proteins / Q000378:metabolism; D011232:Chemical Precipitation; D006224:Cricetinae; D004229:Dithiothreitol / Q000494:pharmacology; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D000091342:Endoplasmic Reticulum Chaperone BiP; D006023:Glycoproteins / Q000737:chemistry / Q000378:metabolism*; D006031:Glycosylation; D006360:Heat-Shock Proteins; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018832:Molecular Chaperones / Q000378:metabolism*; D008970:Molecular Weight; D009154:Mutation; D010084:Oxidation-Reduction; D011134:Polysaccharides / Q000737:chemistry; D011487:Protein Conformation; D017510:Protein Folding; D012261:Ribonucleoproteins / Q000378:metabolism; D012672:Semliki forest virus; D014764:Viral Proteins / Q000737:chemistry / Q000378:metabolism*
chemical_list: D002135:Calcium-Binding Proteins; D037282:Calreticulin; D002352:Carrier Proteins; D000091342:Endoplasmic Reticulum Chaperone BiP; D006023:Glycoproteins; D006360:Heat-Shock Proteins; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D018832:Molecular Chaperones; D011134:Polysaccharides; D012261:Ribonucleoproteins; D014764:Viral Proteins; D037281:Calnexin; D004229:Dithiothreitol