This gene encodes a member of the disulfide isomerase (PDI) family of endoplasmic reticulum (ER) proteins that catalyze protein folding and thiol-disulfide interchange reactions. The encoded protein has an N-terminal ER-signal sequence, a catalytically active thioredoxin domain, one transmembrane domain and a C-terminal ER-retention sequence. This protein is enriched on the mitochondria-associated-membrane of the ER via palmitoylation of two of its cytosolically exposed cysteines. [provided by RefSeq, Jan 2017].