Involved in the secretion of glycoproteins and in nucleus architecture and gene silencing. Interacts with EMP47 in the endoplasmic reticulum membrane in order to be transported to the Golgi apparatus. Interacts with the coatomer proteins COP1, SEC21 and SEC23. The di-lysine motif confers endoplasmic reticulum localization for type I membrane proteins. Belongs to the EMP46/EMP47 family.