Figure 3.

BART binds to an active form of Rac1. (A) GST-tagged Rac1 was incubated with GDP or GTPγS and was then used in pull-down experiments with the recombinant BART protein. Precipitates were examined by Western blot analysis using anti-BART and anti-Rac1 antibodies. Data are representative of three independent experiments. (B) GST-tagged Rac1, a dominant-negative mutated Rac1 form, Rac1N17, or PAK-CRIB was incubated with S2-013 cell lysates, followed by GST-pull-down assays. Precipitates were examined by Western blot analysis using anti-BART and anti-Rac1 antibodies. Data are representative of three independent experiments. (C) Densitometric analysis of the results of B. The level of BART in the precipitates was assessed after normalizing BART signals to Rac1 signals. (D) S2-013 cells were pretreated with or without the Rac1 inhibitor (NSC23766) and were immunocytochemically stained using anti-BART (green) and anti-Rac1 (red) antibodies. Arrows indicate colocalized BART and Rac1 in lamellipodial-like protrusions; blue, DAPI staining. Bars, 10 µm.