The oxidoreductase ERp57 efficiently reduces partially folded in preference to fully folded MHC class I molecules

摘要: The oxidoreductase ERp57 is an integral component of the peptide loading complex major histocompatibility (MHC) class I molecules, formed during their chaperone-assisted assembly in endoplasmic reticulum. Misfolded MHC molecules or those denied suitable peptides are retrotranslocated and degraded cytosol. presence suggests it may be involved reduction intrachain disulfides prior to retrotranslocation. We have studied ability reduce vitro. Recombinant specifically reduced partially folded whereas had little no effect on peptide-loaded molecules. Reductase activity was associated with cysteines at positions 56 405 ERp57, N-terminal residues active CXXC motifs. Our data suggest that reductase unfolding leading targeting for degradation.