Thiredoxin domain-containing protein that participates in various redox reactions through the reversible oxidation of its active center dithiol to a disulfide and catalyze dithiol-disulfide exchange reactions (, ). Acts as a key inhibitor of the alternative triglyceride biosynthesis pathway by inhibiting the activity of TMEM68/DIESL at the endoplasmic reticulum, thereby restricting accumulation of triacylglycerol . The alternative triglyceride biosynthesis pathway mediates formation of triacylglycerol from diacylglycerol and membrane phospholipids . Acts as a protein disulfide isomerase by catalyzing formation or reduction of disulfide bonds (, ). Specifically mediates formation of disulfide bonds of transmembrane proteins at the endoplasmic reticulum membrane . Involved in endoplasmic reticulum-associated degradation (ERAD) via its protein disulfide isomerase activity by acting on folding-defective polypeptides at the endoplasmic reticulum membrane . Acts as a negative regulator of platelet aggregation following secretion in the extracellular space . Acts as a regulator of endoplasmic reticulum-mitochondria contact sites via its ability to regulate redox signals (, ). Regulates endoplasmic reticulum-mitochondria Ca(2+) flux .
Subcellular locations: Endoplasmic reticulum membrane, Mitochondrion membrane, Secreted
Predominantly found in the endoplasmic reticulum . Secreted in the extracellular space following thrombin stimulation . Localizes to mitochondria-associated endoplasmic reticulum membrane (MAM); palmitoylation is required for MAM localization ( ).
Ubiquitous . Highly expressed in kidney, liver, placenta and lung .