Mediates thiol-dependent retention in the early secretory pathway, forming mixed disulfides with substrate proteins through its conserved CRFS motif. Inhibits the calcium channel activity of ITPR1. May have a role in the control of oxidative protein folding in the endoplasmic reticulum. Required to retain ERO1L and ERO1LB in the endoplasmic reticulum. Forms mixed disulfides with both ERO1L and ERO1LB and cargo folding intermediates. Directly interacts with ITPR1 in a pH-, redox state- and calcium-dependent manner, but not with ITPR2 or ITPR3. The strength of this interaction inversely correlates with calcium concentration. By endoplasmic reticulum stress. Note: This description may include information from UniProtKB.
Protein type: Endoplasmic reticulum; Isomerase; Secreted; Secreted, signal peptide
Alt. Names/Synonyms: endoplasmic reticulum resident protein 44 kDa; ER protein 44; ERP44; KIAA0573; PDIA10; protein disulfide isomerase family A, member 10; thioredoxin domain containing 4 (endoplasmic reticulum); thioredoxin domain-containing protein 4; TXNDC4