出版社：American Society for Biochemistry and Molecular Biology
摘要：Sphingolipids comprise a complex group of lipids concentrated in membrane rafts and whose metabolites function as signaling molecules. Sphingolipids are conserved in Drosophila , in which their tight regulation is required for proper development and tissue integrity. In this study, we identified a new family of Drosophila sphingolipids containing two double bonds in the long chain base (LCB). The lipids were found at low levels in wild-type flies and accumulated markedly in Drosophila Sply mutants, which do not express sphingosine-1-phosphate lyase and are defective in sphingolipid catabolism. To determine the identity of the unknown lipids, purified whole fly lipid extracts were separated on a C18-HPLC column and analyzed using electrospray mass spectrometry. The lipids contain a LCB of either 14 or 16 carbons with conjugated double bonds at C4,6. The Δ4,6-sphingadienes were found as free LCBs, as phosphorylated LCBs, and as the sphingoid base in ceramides. The temporal and spatial accumulation of Δ4,6-sphingadienes in Sply mutants suggests that these lipids may contribute to the muscle degeneration observed in these flies.
