Synthesis of sphingolipids with very long chain fatty acids but not ergosterol is required for routing of newly synthesized plasma membrane ATPase to the cell surface of yeast.
The proton pumping H(+)-ATPase, Pma1p, is an abundant and very long-lived polytopic protein of the Saccharomyces cerevisiae plasma membrane. Pma1p constitutes a major cargo of the secretory pathway and thus serves as an excellent model to study plasma membrane biogenesis. We have previously shown that newly synthesized Pma1p is mistargeted to the vacuole in an elo3Delta mutant that affects the synthesis of the ceramide-bound C26 very long chain fatty acid (Eisenkolb, M., Zenzmaier, C., Leitner, E., and Schneiter, R. (2002) Mol. Biol. Cell 13, 4414-4428) and now describe a more detailed analysis of the role of lipids in Pma1p biogenesis. Remarkably, a block at various steps of sterol biosynthesis, a complete block in sterol synthesis, or the substitution of internally synthesized ergosterol by externally supplied ergosterol or even by cholesterol does not affect Pma1p biogenesis or its association with detergent-resistant membrane domains (lipid "rafts"). However, a block in sphingolipid synthesis or any perturbation in the synthesis of the ceramide-bound C26 very long chain fatty acid results in mistargeting of newly synthesized Pma1p to the vacuole. Mistargeting correlates with a lack of newly synthesized Pma1p to acquire detergent resistance, suggesting that sphingolipids with very long acyl chains affect sorting of Pma1p to the cell surface.
Gaigg
Barbara
B
Division of Biochemistry, University of Fribourg, Chemin du Musée 5, CH-1700 Fribourg, Switzerland.
Timischl
Birgit
B
Corbino
Linda
L
Schneiter
Roger
R
D000252:Calcium-Transporting ATPases / Q000737:chemistry* / Q000378:metabolism; D027682:Cation Transport Proteins / Q000737:chemistry* / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism*; D003001:Cloning, Molecular; D004247:DNA / Q000378:metabolism; D003902:Detergents / Q000494:pharmacology; D004875:Ergosterol / Q000378:metabolism*; D005227:Fatty Acids / Q000737:chemistry*; D005838:Genotype; D006028:Glycosphingolipids / Q000737:chemistry; D050356:Lipid Metabolism; D008856:Microscopy, Fluorescence; D008954:Models, Biological; D009154:Mutation; D053499:Plasma Membrane Calcium-Transporting ATPases; D021381:Protein Transport; D006180:Proton-Translocating ATPases / Q000378:metabolism / Q000502:physiology*; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism / Q000502:physiology*; D013107:Sphingolipids / Q000737:chemistry*; D013696:Temperature; D013997:Time Factors
D027682:Cation Transport Proteins; D003902:Detergents; D005227:Fatty Acids; D006028:Glycosphingolipids; D029701:Saccharomyces cerevisiae Proteins; D013107:Sphingolipids; C477937:inositolphosphorylceramide; D004247:DNA; C092477:PMA1 protein, S cerevisiae; D006180:Proton-Translocating ATPases; D053499:Plasma Membrane Calcium-Transporting ATPases; D000252:Calcium-Transporting ATPases; D004875:Ergosterol