FIG. 6.

Effect of guanine nucleotides on caspase 3-mediated cleavage of wild-type and mutant Rac1. Recombinant purified His-tagged wild-type Rac1 (Rac1wt), a constitutively active, GTP-bound Rac1 (Rac1V12), and a dominant-negative, nucleotide-depleted form of Rac1 (Rac1N17), all at 100 ng/μl, were treated with caspase 3 (5 ng/μl) in caspase buffer in the absence or presence of 100 μM GTP. The cleavage of Rac1 proteins was assessed at the indicated times by immunoblotting with anti-Rac1 (C-11) antibody, as described for Fig. 1.