Figure 8.
YPC1 and YDC1 control sphingolipid levels in lag1Δlac1Δ mutant cells. Cells of wild-type (WT), lag1Δlac1Δ cells (ΔΔ), lag1Δlac1Δ cells overexpressing YPC1 (ΔΔ YPC1), lag1Δlac1Δ cells overexpressing YDC1 (ΔΔ YDC1), or the quadruple deletion strain lag1Δlac1Δypc1Δydc1Δ (ΔΔΔΔ) were grown overnight in the presence of either (A) [32P]phosphate or (B) [3H]dihydrosphingosine. Whole cell lipid extracts were hydrolyzed with mild base, desalted, and analyzed on HPTLC plates resolved in solvent B. Labeled lipids were quantified with the use of a phosphorimager. Abbreviations: see legend to Figure 3. Note that in lag1Δlac1Δypc1Δydc1Δ strain the sphingolipids IPC and M(IP)2C are completely absent.