MEDIAL-GOLGI RETENTION OF N-ACETYLGLUCOSAMINYLTRANSFERASE-I - CONTRIBUTION FROM ALL DOMAINS OF THE ENZYME

Abstract

We have previously shown that the transmembrane domain and flanking residues of beta-1,2-N-acetylglucosaminyltransferase I (GnTI) can localize a hybrid molecule to medial-Golgi cisternae (Burke, J., Pettitt, J. M., Schachter, H., Sarkar, M., and Gleeson, P.A. (1992) J. Biol. Chem. 267, 24433-24440). Here, we have further examined the contribution of the cytoplasmic tail, transmembrane domain, and the catalytically active, luminal domain of GnTI in medial-Golgi localization, by analyzing the localization of hybrid molecules stably expressed in murine cells. In contrast to wild-type GnTI, which was efficiently localized to the medial-Golgi and not detected at the cell surface, hybrid molecules..