Constituent of COPII-coated endoplasmic reticulum-derived transport vesicles. Required for efficient transport of a subset of secretory proteins to the Golgi. Facilitates retrograde transport from the Golgi to the endoplasmic reticulum (By similarity). Recycles between endoplasmic reticulum and Golgi. Resides in the endoplasmic and Golgi compartments, and then packaged into endoplasmic reticulum derived vesicles (By similarity). Belongs to the ERGIC family.