Affiliation:
1. Department of Cell Biology, Medical School AZU H02.314, University of Utrecht, The Netherlands.
Abstract
Sphingomyelin is a major lipid of the mammalian cell surface. The view that sphingomyelin, after synthesis in the Golgi lumen, reaches the outer leaflet of the plasma membrane on the inside of carrier vesicles has been challenged by inconsistencies in the results of transport studies. To investigate whether an alternative pathway to the cell surface exists for sphingomyelin, brefeldin A and mitotic cells were used to block vesicular traffic between the Golgi complex and the plasma membrane. Exogenous sphingomyelinase was applied in the cold to assay for the presence of sphingomyelin on the surface of CHO cells. Newly synthesized radiolabeled sphingomyelin was found to equilibrate with cell surface sphingomyelin within 1.5 hours at 37 degrees C. Brefeldin A and mitosis inhibited this transport but, surprisingly, not the surface appearance of the short-chain sphingomyelin analog N-6[7-nitro-2,1,3-benzoxadiazol-4-yl]aminohexanoyl(C6-NBD)-sphingo myelin as assayed by depletion of this lipid in the medium by the scavenger albumin. Transport of C6-NBD-sphingomyelin in the presence of brefeldin A was blocked by cyclosporin A and PSC 833, inhibitors of the multidrug resistance P-glycoprotein. The same was observed in HepG2 and HeLa cells, and for short-chain glucosylceramide, which demonstrates the general nature of the transporter-dependent sphingolipid translocation across the plasma membrane.
Publisher
The Company of Biologists
Reference52 articles.
1. Comparative study of the metabolic pools of sphingomyelin and phosphatidylcholine sensitive to tumor necrosis factor.;Andrieu;Eur. J. Biochem,1996
2. Transport of biosynthetic sphingolipids from Golgi to plasma membrane in HT29 cells: involvement of different carrier vesicle populations.;Babia;Eur. J. Cell Biol,1994
3. In vivo circumvention of P-glycoprotein-mediated multidrug resistance of tumor cells with SDZ PSC 833.;Boesch;Cancer Res,1991
4. Brefeldin A-induced increase of sphingomyelin synthesis.;Bruning;J. Biol. Chem,1992
5. Topology of sphingolipid galactosyltransferases in ER and Golgi: transbilayer movement of monohexosyl sphingolipids is required for higher glycosphingolipid biosynthesis.;Burger;J. Cell Biol,1996
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