Potential role in vesicular protein trafficking, mainly in the early secretory pathway. Appears to play a role in the biosynthesis of secreted cargo including processing and post-translational modifications. Predominantly monomeric and to lesser extent homodimeric in endoplasmic reticulum, endoplasmic reticulum-Golgi intermediate compartment and cis-Golgi network. Oligomerizes with other members of the EMP24/GP25L family such as TMED2, TMED9 and TMED10. Interacts (via C-terminus) with COPG1; the interaction involves dimeric TMED7. Cycles between compartments of the early secretatory pathway. N-linked glycosylated in complex form containing terminal sialic acid. Belongs to the EMP24/GP25L family.