FIG. 3.

Lipids extracted from growing cells exposed to either heat shock (45°C) or 2-DG or to both stresses together, with 30°C being the normal growth temperature. The lipids were separated by TLC, and index marks to the left of each fluorogram denote migration positions of sphingolipid standards in descending order: C₁₈-ceramide, C₁₈-phytoceramide, human glucocerebrosides, and sphingosine. [³H]palmitate (1 μCi/ml) was added at 60 min of stress, and the cells were harvested for extraction after an additional 15 min. [³H]serine (1 μCi/ml) was added at the time of stress, and the cells were harvested after an additional 60 min.