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 ERO1A and ERO1B in the endoplasmic reticulum (, ).
Subcellular locations: Endoplasmic reticulum lumen