FIGURE 5.

CerS isoforms differentially utilize d16:0-dihydrosphingosine for dihydroceramide synthesis. Cell extracts were prepared from cells overexpressing individual CerS or empty vector. CerS activity was assayed with d16:0- or d18:0-DHS and either [¹⁴C]stearoyl-CoA (A) or [¹⁴C]palmitoyl-CoA (B). Controls for CerS1, CerS5, and CerS6 were transfected with 50 μg of the pCMV vector, whereas controls for CerS4 were transfected with 100 μg of the vector, as indicated. Results are means ± S.E. (error bars). *, p < 0.05 versus d18:0-DHS.