Post-translational modifications distinguish cell surface from golgi-retained β1,4 galactosyltransferase molecules. Golgi localization involves active retention

Abstract

β1,4 Galactosyltransferase (GalT) is a membrane-bound enzyme localized predominantly to the trans-Golgi cisternae. Our previous studies have shown that the transmembrane domain of bovine GalT plays a critical role in Golgi localization (Teasdale,R.D., D'Agostaro,G. and Gleeson,P.A., J. Biol. Chem., 267, 4084-4096, 1992). Here we have compared the localization and post-translational modifications of fulllength bovine GalT with a GalT/hybrid molecule where the transmembrane domain of GalT was replaced with that of the transferrin receptor. GalT/hybrid molecules were expressed on the surface of transfected cells; however, differences were observed in the distribution of the hybrid molecules bet..