A new GFP-based sensor for active Rac1 and Rac2. (A) Pull-down experiments with recombinant GST, GST-Rac1, -Rac2, and -Cdc42 proteins. GSH-sepharose-bound GST-Cdc42 was preloaded with GDP or GTP γS and incubated with S2 cell lysate transfected with MBT-GFP. Bead-bound complexes were probed for binding of MBT-GFP protein by an anti-GFP antibody. (B) Quantification of (A) from three independent experiments. Signals were normalized to GST. Mean ± SD. To evaluate statistical significance, the Mann-Whitney test was used and following P values (two- tailed) were obtained: P value: ** <0.001, * <0.05 and ns > 0.05. Source data are available for this figure: SourceData FS2.