Either depletion of Arf6 or RhoB or expression of RhoBΔGCI regulates actin stress fibers and FA dynamics. (A) SKBr3 cells cotransfected with actin-mCherry and RhoB/Arf6 siRNAs or Arf6/RhoB/RhoBΔGCI were stimulated with 0.5 nM HGF (20 min). Insets show enlarged region from the cell leading edge. CTL, control. (B) Percentage of cells with reduced actin cables were scored. (C) Number of fluorescence peaks representing stress fibers in SKBr3 cells from A are shown. (D) SKBr3 cells cotransfected with Paxillin-EGFP and RhoB/Arf6 siRNAs or Arf6/RhoB/RhoBΔGCI cDNAs were stimulated with 0.5 nM HGF (20 min). Insets show enlarged region from the cell leading edge. (E and F) Percentage of cells with small FAs (E) and number of FAs (F) were scored. All quantified data indicate mean values ± SEM from three independent experiments. Scale bar = 10 µm; 2 µm for magnification. P values based on comparisons with control: n.s., nonsignificant; **, P < 0.001.