FIG. 6.

H₂O₂ scavengers and the NADPH oxidase inhibitor, DPI, inhibit Fer and cortactin phosphorylation induced by cell substratum engagement. (A) Fn-induced tyrosine phosphorylation of Fer at 25 min (expressed as a ratio of Fer pY to Fer in IP/IB analysis) was attenuated by the H₂O₂ scavengers NAC and Tiron and the NADPH oxidase inhibitor, DPI (*, P = 0.04, 0.01, and 0.002, respectively). The mitochondrial superoxide production inhibitor rotenone caused a partial inhibitory effect on Fer pY, although this change was not statistically significant. (B) Fn-induced phosphorylation of Ctn at 25 min (expressed as a ratio of pY421-Ctn to total Ctn) was also attenuated by NAC, Tiron, and DPI (*, P = 0.0044, 0.0007, and 0.0046, respectively). Rotenone had no effect on adhesion-induced Ctn phosphorylation.