Ganglioside glycosyltransferases and newly synthesized gangliosides are excluded from detergent-insoluble complexes of Golgi membranes

CRESPO P.M,; ZURITA A.R,; GIRAUDO C,; MACCIONI H.J.F,; JOSE LUIS DANIOTTI

BIOCHEMICAL JOURNAL

Portland Press

Lugar: Londres; Año: 2004 vol. 377 p. 561 - 561

0264-6021

font face="Times-Roman" size="2"> GEM(glycosphingolipid-enrichedmicrodomains) are specialized detergent-resistant domains of the plasma membrane in which some gangliosides concentrate. Although genesis of GEM is considered to occur in the Golgi complex, where the synthesis of gangliosides also occurs, the issue concerning the incorporation of ganglioside species into GEM is still poorly understood. In this work, using Chinese hamster ovary K1 cell clones with different glycolipid compositions, we compared the behaviour with cold Triton X-100 solubilization of plasma membrane ganglioside species with the same species newly synthesized in Golgi membranes. We also investigated whether three ganglioside glycosyltransferases (a sialyl-, a N-acetylgalactosaminyl- and a galactosyl-transferase) are included or excluded from GEM in Golgi membranes. Our data show that an important fraction of plasma membrane GM3