p53 deficiency causes elevated Rac1 activity. BL41 and BL41ts cells (left panel) and J3D and J3Dts cells (right panel) were cultured for 24 hours at 32°C or 37°C. Cell lysates were subjected to GST-PAK pull-down assay and processed for Western immunoblot with anti-p53 or anti-Rac antibodies. β-actin served as a loading control. The J3D bands displayed were part of the same gel, yet were separated by other lanes. The bands from at least 2 independent experiments were quantified by densitometry and displayed below. Error bars represent SD.