May play a role in retrograde transport of proteins from the Golgi to the endoplasmic reticulum. May indirectly play a role in protein glycosylation in the Golgi. Homooligomer (PubMed:24806965). Interacts with COPB1 (PubMed:24806965). May interact with LMAN1 (PubMed:24806965). Interacts with the COG complex; probably through COG3 (PubMed:24806965). Expressed strongly in kidney and skeletal muscle, followed by liver, placenta, pancreas, and lung, with low amounts in heart and only traces in brain (PubMed:11085536). Widely expressed with ubiquitous expression in epithelial tissues (at protein level) (PubMed:17973242). Belongs to the TMEM115 family.