Figure 4. Metabolic conversion of caCers by SMS2 in cell lysates can be switched on and off by light.

(a) caCer-1, caCer-3 or cCer were incubated with lysates of SMS2-expressing yeast cells at 37°C under UV-A or blue illumination. After each 10 min period, the caCer configuration was switched by illuminating the reactions with blue or UV-A light. Reaction samples were taken at the indicated time points, subjected to lipid extraction, click-reacted with Alexa-647 and then analyzed by TLC. Presented are the relative amounts of SM formed per time point. (b) Presented are the relative SM production rates (a.u. of SM formed per min) calculated from the time points presented in (a). Data shown are average values ± s.d. from four technical replicates (n = 4).