Endoplasmic reticulum and mitochondria-associated protein that probably functions as a regulator of cellular redox state and thereby regulates protein post-translational modification, protein folding and mitochondrial activity. Indirectly regulates neuronal proliferation, migration, and organization in the developing brain. Monomer (PubMed:31735293). Homodimer; disulfide-linked (PubMed:31735293). Occurs in both reduced and oxidized monomeric form (PubMed:31735293). Oxidative conditions increase homodimerization (PubMed:31735293). Interacts with CANX (PubMed:31735293). Interacts with ATP2A2 (PubMed:31735293). Localizes to endoplasmic reticulum mitochondria-associated membrane (MAMs) that connect the endoplasmic reticulum and the mitochondria. Widely expressed. The thioredoxin domain lacks the 2 redox-active cysteines, suggesting that it lacks thioredoxin activity. The di-lysine motif confers endoplasmic reticulum localization for type I membrane proteins. The disease is caused by variants affecting the gene represented in this entry.