Translocation Associated Membrane Protein 1 (TRAM1)

TRAM1 is a multi-pass membrane protein that is part of the mammalian endoplasmic reticulum. The protein influences glycosylation and facilitates the translocation of secretory proteins across the endoplasmic reticulum membrane by regulating which domains of the nascent polypeptide chain are visible to the cytosol during a translocational pause. TRAM is a 374-amino acid, 8-pass transmembrane protein that shares 95% amino acid identity with the canine protein. TRAM contains a potential N-terminal N-linked glycosylation site and a C-terminal 60-residue cytosolic portion. Immunoblot analysis showed that TRAM is an abundantly expressed, approximately 36-kD microsomal glycoprotein. Functional analysis indicated that TRAM influences glycosylation and is stimulatory or required for the translocation of secretory proteins.