FIG. 5.

Glucose and 2-DG modification of lipids in stressed cells. [³H]glucose (1 μCi/ml) or [³H]2-DG (1 μCi/ml) was provided to cells between 15 and 30 min after transfer to 45°C. Wild-type and Δgcs cells were radiolabeled with [³H]palmitic acid for 15 min, either at 30°C or beginning 15 min after transfer to 45°C; 2-DG was added 15 min prior to radiolabel. Little or none of the 2-DG-modified ceramide is made by Δgcs cells, but there is strong synthesis of the dual-stress-induced C₁₈(OH)-phytoceramide. Lipids were separated by TLC, and C₁₈-ceramide, C₁₈-phytoceramide, cerebrosides, and sphingosine (descending order) were standards (indicated by index marks). For alignment, all the sample lanes were run together on a single TLC plate, but the left panel ([³H]glucose) was substituted from a similar fluorogram.