Fig. 3.

The metabolic conversion of 1-deoxySLs is slower than for canonical SLs. A: MEFs were treated with either 1 μM d7-SA or d3-deoxySA for a 2 h pulse, followed by a chase period in unsupplemented growth medium up to 48 h. The pulse medium was also collected and the d7-SA and d3-deoxySA content was measured. The total d3-labeled 1-deoxySLs (including the new metabolites) decreased over the chase period, although less than the d7-labeled canonical SLs did. While the total d7-labeled SLs were already much lower at time point 0, this was not a function of availability of the labeled lipids, as can be seen by the points at −2 h, which represent the total amount of d3-deoxySA and d7-SA in the pulse medium. B: MEFs were treated with a 2 h pulse of d3-deoxySA, followed by a chase period up to 8 days in unsupplemented growth medium. All of the d3-deoxySL metabolites increased until 4–6 days, and then drastically decreased by the final time point at 8 days. Data are represented as mean ± SEM.