FIGURE 3:

Arf6 is essential for proper HD organization. (A, B) Confocal images of the basal membrane and associated quantification of the amount of HDs (from ITGA6 staining) at the basal membrane of cells transfected with control or (A, B) or Arf6 siRNAs and then immunostained for ITGA6 and CK14 (A). The Rescue column (B) corresponds to cells transfected with Arf6 siRNAs plus a plasmid encoding wild-type RFP-Arf6 plasmid mutated to be Arf6 siRNA-resistant (Rescue). Scale bar = 10 µm. Data are from three independent experiments; number of cells = 40, 46, and 45. Student’s t tests: siCTL vs. siArf6 or Rescue. (C) Confocal images of the basal membrane of cells expressing EGFP-Arf6(wt) or (T27N) immunostained for ITGA6. Scale bar = 10 µm. (D) Quantification of the amount of HDs (from ITGA6 staining) at the basal membrane of cells expressing mutant forms of Arf6 from three independent experiments; number of cells = 37, 42, 61, and 63. Student’s t tests: Arf6(wt) vs. NT, Arf6(T27N). or Arf6(Q67L). (E) Confocal images of the basal membrane of cells expressing EGFP-Arf6(Q67L) immunostained for ITGA6 and CK14. Scale bar = 10 µm. (E′) Magnification of the boxed region in E (magnification ×3). Arrowheads highlight the colocalization of Arf6 (red) and ITGA6 (green) at the basal plasma membrane. (F) Quantification of the presence of Arf6 in ITGA6-enriched intracellular compartments in cells expressing mutant forms of Arf6 from three independent experiments; number of cells = 45, 44, and 46. Student’s t tests: Arf6(wt) vs. Arf6(T27N) or Arf6(Q67L).