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

The membrane anchor of Hl(A4-33A) was found not to be sufficient to retain a reporter protein, the exoplasmic portion of aminopeptidase N, in the Golgi. In addition, the particular sequence of the transmembrane segment is also not necessary for Golgi localization, since it can be replaced by an artificial sequence of 19 consecutive leucines without affecting the fate of the protein. The exoplasmic domain is thus responsible for the interaction of truncated H1 mutants with Golgi components. It remains to be investigated what the potential interaction partners in the trans-Golgi might be.