GTP-binding protein involved in transport from the endoplasmic reticulum to the Golgi apparatus (By similarity). Activated by the guanine nucleotide exchange factor PREB (By similarity). Involved in the selection of the protein cargo and the assembly of the COPII coat complex (By similarity). Synergizes with the cargo receptor SURF4 to mediate the export of lipoproteins from the endoplasmic reticulum, thereby regulating lipoprotein delivery and the maintenance of lipid homeostasis .
Subcellular locations: Endoplasmic reticulum membrane, Golgi apparatus, Golgi stack membrane
Associated with the endoplasmic reticulum and Golgi stacks, in particular in the juxta-nuclear Golgi region.
Expressed in many tissues including small intestine, liver, muscle and brain.