Figure 4.

Δlbp1 accumulates LCBP, has reduced levels of ceramide, and fails to incorporate exogenous dihydrosphingosine into sphingolipids. Strains W3031A (lanes 1, 3, and 6), lbp1–1 (lane 2), Δlbp 1 (lanes 4 and 7), or Δlbp2 (lanes 5 and 8) were labeled with the sphingolipid precursors: [³H]palmitate (lanes 1 and 2), [³H]serine (lanes 3–5), or [³H]dihydrosphingosine (lanes 6–8), and the lipids were extracted and processed as described in Materials and Methods and separated by using TLC. Migration of standards is indicated: CER, ceramide; GPE, glycerophosphate ethanolamine; GPS, glycerophosphate serine; GPC, glycerophosphate choline; all other standards as described in Fig. 1.