trans-Golgi retention of a plasma membrane protein: mutations in the cytoplasmic domain of the asialoglycoprotein receptor subunit H1 result in trans-Golgi retention

An alternative model proposed by Bretscher and Munro (1993) implicates the length of the transmembrane segment in relation to the differing lipid compositions in the compartments of the secretory pathway. Shorter transmembrane segments would be retained in the Golgi, whereas longer ones would be transported further. Hence, it is conceivable that the size of the cytoplasmic domain might have an effect on the positioning of the transmembrane segments of the H1 oligomer within the lipid bilayer and, as a result, on how the exoplasmic domain is exposed in the lumen.