Which molecular chaperone is responsible for stabilizing unfolded proteins in the ER?
Stabilization of unfolded secretory proteins inside endoplasmic reticulum oxidizing environment depends on lectin chaperone system that monitors glycosylation status and provides time for folding. Calreticulin, soluble paralog of membrane-bound calnexin sharing lectin domain but lacking transmembrane anchor, resides in ER lumen at millimolar concentration. It binds specifically monoglucosylated Glc1Man9GlcNAc2 N-glycans generated after glucosidase I and II trimming of precursor added en bloc. Its long proline-rich P-domain arm extends to recruit oxidoreductase ERp57 forming mixed disulfides wi
Ref: Braakman & Hebert, Cold Spring Harb Perspect Biol 5: 2013, Calreticulin Chaperone Role.