Figure 4.

Palmitoylation of the Fas receptor regulates its stability. (a) Total lysates from SW480 Fas WT and SW480 Fas C199V exposed to 100 μg/ml of the protein synthesis inhibitor cycloheximide (CHX) for 4, 6, 8 and 16 h were resolved by SDS-PAGE and immunoblotted with anti-Fas and anti-Ezrin antibodies. (b) A protein surface biotinylation protocol was performed on SW480 Fas WT and Fas C199V cells. Following the biotinylation step, cells were cultured for the indicated time, lysed, and cell lysate was submitted to streptavidin immunoprecipitation, SDS-PAGE and immunoblotting. Fas expressed at cell surface and biotinylated at t=0 was detected by anti-Fas antibody and EGFR was used as an internal control for equivalent protein surface biotinylation. Quantification of biotinylated Fas represented at the bottom of the figure is a mean of three independent experiments