Endoplasmic reticulum resident protein 44 (ERP44)

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 keep ERO1A and ERO1B in the endoplasmic reticulum.