EC chemokinesis stimulated by Ang-1. (A) GTPase activity in ECs carrying vector alone or N19RhoA and N17Rac1 was stimulated for 5 and 120 minutes, respectively, (or 2 minutes, data not shown) with Ang-1 (20 ng/mL). indicates unstimulated cells (-); ▪ indicates Ang-stimulated cells (+) exactly as in Figure 4D. Densitometric and statistical analysis have been performed as in Figure 4D. The panel is representative of 4 experiments. (B) ECs carrying N17Rac1 (i-vi) and N19RhoA (vii-xii) were stimulated with vehicle (i-iii and vii-ix) or Ang-1 (20 ng/mL) for 2 (iv-vi) and 5 minutes (x-xii), respectively. N17Rac1 ECs were incubated with GST-PBD (i,iv) and N19RhoA ECs with GST-RBD (vii,x). GFP shows infected ECs (ii,v,viii,xi). GST-PBD staining (red) and GFP (green) are merged in panels ix and xii. Arrows and arrowheads indicate GFP-positive and GFP-negative cells, respectively. In this experiment, ECs were infected at 50% of efficiency. Scale bar equals 10 μm. (C) ECs carrying vector alone or N19RhoA and N17Rac1 were plated in confluent colonies, starved, and then stimulated with Ang-1 (20 ng/mL) or vehicle. Images were extracted at beginning and after 5 hours of stimulation by time-lapse videomicroscopy (magnification, × 100) (D) Motility was expressed as micrometers per hour as detailed in “Materials and methods.” Mean ± SD of 5 experiments.