Ganglioside GD3 traffics from trans-Golgi network to plasma membrane by a Rab11-independent and Brefeldin A-insensitive exocytic pathway

CRESPO P.M,; IGLESIAS-BARTOLOMÉ R,; JOSE LUIS DANIOTTI

JOURNAL OF BIOLOGICAL CHEMISTRY

American Society for Biochemistry and Molecular Biology, Inc

Lugar: Bethesda; Año: 2004 vol. 279 p. 47610 - 47610

0021-9258

angliosides, complex glycosphingolipids containing sialic acids, have been found to reside in glycosphingolipid-enriched microdomains (GEM) at the plasma membrane. They are synthesized in the lumen of the Golgi complex and appear unable to translocate from the lumenal toward the cytosolic surface of Golgi membrane to access the monomeric lipid transport. As a consequence, they can only leave the Golgi complex via the lumenal surface of transport vesicles. In this work we analyzed the exocytic transport of the disialo ganglioside GD3 from trans-Golgi network (TGN) to plasma membrane in CHO-K1 cells by immunodetection of endogenously synthesized GD3. We found that ganglioside GD3, unlike another luminal membrane-bounded lipid (glycosylphosphatidylinositol-anchored protein), did not partition into GEM domains in the Golgi complex and trafficked from TGN to plasma membrane by a brefeldin A-insensitive exocytic pathway. Moreover, a dominant negative form of Rab11, which prevents exit of ve