Protein disulfide isomerase (PDI) is a multifunctional protein that catalyzes the formation, breakage and rearrangement of disulfide bonds. At the cell surface, the protein seems to act as a reductase that cleaves disulfide bonds of proteins attached to the cell. It may therefore cause structural modifications of exofacial proteins. Inside the cell, PDI seems to form/rearrange disulfide bonds of nascent proteins. At high concentrations, it functions as a chaperone that inhibits aggregation of misfolded proteins. At low concentrations, it facilitates aggregation (anti-chaperone activity). PDI may be involved with other chaperones in the structural modification of the TG precursor in hormone biogenesis. It also acts a structural subunit of various enzymes such as prolyl 4-hydroxylase and microsomal triacylglycerol transfer protein MTTP. Receptor for LGALS9; the interaction retains P4HB at the cell surface of Th2 T helper cells, increasing disulfide reductase activity at the plasma membrane, altering the plasma membrane redox state and enhancing cell migration.
For Research Use Only. Not for use in diagnostic procedures. Not for resale without express authorization.
Protein Aliases: CaO19.12595; Cellular thyroid hormone-binding protein; collagen prolyl 4-hydroxylase beta; Endoplasmic reticulum resident protein 59; Eps1p; ER protein 59; glutathione-insulin transhydrogenase; p55; PDI; PDI1P; procollagen-proline, 2-oxoglutarate 4-dioxygenase (proline 4-hydroxylase), beta polypeptide; prolyl 4-hydroxylase beta polypeptide; Prolyl 4-hydroxylase subunit beta; prolyl 4-hydroxylase, beta polypeptide; protein disulfide isomerase; Protein disulfide isomerase (Prolyl 4-hydroxylase, beta polypeptide); protein disulfide isomerase family A, member 1; protein disulfide isomerase-associated 1; protein disulfide isomerase/oxidoreductase; Protein disulfide-isomerase; protocollagen hydroxylase; testicular secretory protein Li 32; thyroid hormone-binding protein p55
Gene Aliases: CLCRP1; DSI; ERBA2L; ERp59; GIT; P4HB; P4Hbeta; PDI; PDIA1; PDIR; PHDB; PO4DB; PO4HB; PROHB; Thbp
Molecular Function: chaperone