Interaction of the thiol-dependent reductase ERp57 with nascent glycoproteins.
Calnexin and calreticulin interact specifically with newly synthesized glycoproteins in the endoplasmic reticulum (ER) and function as molecular chaperones. The carbohydrate-specific interactions between ER components and glycoproteins synthesized in isolated canine pancreatic microsomes were analyzed using a cross-linking approach. A carbohydrate-dependent interaction between newly synthesized glycoproteins, the thiol-dependent reductase ERp57, and either calnexin or calreticulin was identified. The interaction between ERp57 and the newly synthesized glycoproteins required trimming of the N-linked oligosaccharide side chain. Thus, it is likely that ERp57 functions as part of the glycoprotein-specific quality control machinery operating in the lumen of the ER.
Oliver
J D
JD
School of Biological Sciences, University of Manchester, 2.205 Stopford Building, Oxford Road, Manchester M13 9PT, UK. shigh@fs2.scg.man.ac.uk
van der Wal
F J
FJ
Bulleid
N J
NJ
High
S
S
D000818:Animals; D002135:Calcium-Binding Proteins / Q000378:metabolism; D037281:Calnexin; D037282:Calreticulin; D004285:Dogs; D004721:Endoplasmic Reticulum / Q000201:enzymology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005656:Fungal Proteins / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D005959:Glucosidases / Q000037:antagonists & inhibitors; D006023:Glycoproteins / Q000378:metabolism*; D006031:Glycosylation; D006360:Heat-Shock Proteins / Q000378:metabolism*; D007212:Indolizines / Q000494:pharmacology; D007535:Isomerases; D008861:Microsomes / Q000378:metabolism; D008970:Molecular Weight; D010088:Oxidoreductases / Q000378:metabolism*; D010179:Pancreas / Q000378:metabolism; D011388:Prolactin / Q000378:metabolism; D011498:Protein Precursors / Q000378:metabolism; D012261:Ribonucleoproteins / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D054836:Indolizidines
D002135:Calcium-Binding Proteins; D037281:Calnexin; D037282:Calreticulin; D004791:Enzyme Inhibitors; D005656:Fungal Proteins; D005947:Glucose; D005959:Glucosidases; D006023:Glycoproteins; D006360:Heat-Shock Proteins; D007212:Indolizines; D007535:Isomerases; D010088:Oxidoreductases; D011388:Prolactin; D011498:Protein Precursors; D012261:Ribonucleoproteins; D029701:Saccharomyces cerevisiae Proteins; C048632:MF(ALPHA)1 protein, S cerevisiae; C037806:castanospermine; D054836:Indolizidines