FIG. 3.

Involvement of Rac1, RhoA, and Cdc42 in NF-κB activation induced by p19Arf or p53 deletion. The NF-κB promoter-driven luciferase reporter was transiently expressed in the indicated MEF cells together with a vector expressing Arf, p53, or dominant negative mutants of Rho GTPases (A and B). After a 30-hour recovery followed by a 12-hour starvation, the luciferase activities in the cells were measured. The luciferase activities were expressed as the fold of activation relative to the activity induced by the empty vector alone in the wild-type (WT) cells and were normalized to an internal transfection control (β-galactosidase coexpressed with pCMV vector). To detect NF-κB protein levels (C), nuclear extracts containing 20 μg of proteins were separated by 10% SDS-polyacrylamide gel electrophoresis and the amount of NF-κB present was probed by anti-NF-κB p65 antibody. Anti-beta actin blotting was carried out in parallel as a loading control.