Scambio activates endogenous Rho (A) Kinetics of Rho activation by Scambio. CHO-K1 cells were transfected with either vector (indicated as a – below the panel) or with Scambio (indicated with a +), serum-starved and then stimulated with 10% serum for the number of minutes indicated above the panel. (B) Comparison of activation of endogenous Rho by Dbl and by Scambio. Cells were transfected with vector (lanes 1, 2), Dbl (lanes 3, 4) or Scambio (lanes 5, 6) and the levels of activated Rho determined as described in the legend to Fig. 6. The amount of GTP-Rho was quantitated by immunoblotting using a monoclonal antibody that recognizes an epitope common to Rho. Similar results were obtained in more than two other independent experiments.