Figure 2.

Ceramide synthase inhibition blocks 1-deoxysphingolipid anabolism. Cells were incubated with 1 μM doxSA mix in the absence or presence of the ceramide synthase inhibitor fumonisin B1 (FB1) for 24 h. Cellular lipids were extracted and extracts split. Corresponding samples were analyzed by TLC for fluorescent metabolites (A,B) or by MS for specifically fragmenting metabolites (C). Comigrating or internal standards were used for identification or quantification. Fluorescent TLC images (A) of cellular alkyne lipids were used to calculate the proportion of the alkyne deoxysphingolipids in cells (B). Note that samples lacking inhibitor are 1.5-fold brighter. Cellular alkyne metabolites were further characterized by quantitative MS analysis (C). All data are average with range, N = 2. bg, background; ori, origin