This gene encodes a member of the protein disulfide isomerase (PDI) family of endoplasmic reticulum (ER) proteins. It has an inferred N-terminal signal peptide, a catalytically active thioredoxin (TRX) domain, two TRX-like domains and a C-terminal ER-retention sequence. This protein functions as a pH-regulated chaperone of the secretory pathway and likely plays a role in protein quality control at the endoplasmic reticulum - Golgi interface. [provided by RefSeq, Dec 2016].