A. Western blot of RhoA protein in whole cell lysates of the T cell lines HPB-ALL and CEM. B. Electroporation of C3 efficiently ADP-ribosylates Rho in the T cell line HPB-ALL. Cells were untreated, electroporated in the presence of C3 (25 μg/ml), or electroporated in control buffer. After a 1 hr incubation at 37°C, cells were further ADP-ribosylated as described in Experimental Procedures by the addition of exogenous C3 and [32P]-NAD after cell disruption.