FIGURE 6:

Expression of Arf6, but not the JIP-binding defective mutant of Arf6, rescues macropinocytosis in Arf6-depleted cells. HT1080 cells were seeded to six-well plates and either left untreated (control) or depleted for Arf6 with siRNA for 48 h. Subsequently, control cells were transfected with GFP vector and Arf6-depleted cells were either untransfected or transfected with siRNA-resistant forms of Arf6-GFP or Arf6TKN-GFP for 16–24 h. All sets of cells were then incubated with dextran-647 for 20 min, and dextran uptake was measured by flow cytometry. Bar graphs show the geometric mean dextran fluorescence of GFP-positive cells, reported as a fraction of control, from three separate experiments (GFP-positive cells were gated from a total of 100,000 cells per experiment). An ordinary one-way ANOVA was used to do a multiple comparison test between all groups, and a multiplicitiy adjusted p value is reported for each comparison. Error bars represent ± SD.