Role of EDEM in the release of misfolded glycoproteins from the calnexin cycle

Science. 2003 Feb 28;299(5611):1397-400. doi: 10.1126/science.1079474.

Abstract

The mechanisms that determine how folding attempts are interrupted to target folding-incompetent proteins for endoplasmic reticulum-associated degradation (ERAD) are poorly defined. Here the alpha-mannosidase I-like protein EDEM was shown to extract misfolded glycoproteins, but not glycoproteins undergoing productive folding, from the calnexin cycle. EDEM overexpression resulted in faster release of folding-incompetent proteins from the calnexin cycle and earlier onset of degradation, whereas EDEM down-regulation prolonged folding attempts and delayed ERAD. Up-regulation of EDEM during ER stress may promote cell recovery by clearing the calnexin cycle and by accelerating ERAD of terminally misfolded polypeptides.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aspartic Acid Endopeptidases / chemistry
  • Aspartic Acid Endopeptidases / metabolism*
  • Calnexin / metabolism*
  • Cell Line
  • Down-Regulation
  • Electrophoresis, Polyacrylamide Gel
  • Endoplasmic Reticulum / metabolism*
  • Glycoproteins / chemistry
  • Glycoproteins / metabolism*
  • Glycosylation
  • Humans
  • Kinetics
  • Membrane Proteins / metabolism*
  • Molecular Weight
  • Polysaccharides / metabolism
  • Protein Conformation
  • Protein Folding
  • RNA Interference
  • Transfection
  • Up-Regulation

Substances

  • EDEM1 protein, human
  • Glycoproteins
  • Membrane Proteins
  • Polysaccharides
  • Calnexin
  • Aspartic Acid Endopeptidases