Peroxynitrite generation in Cav-1^−/− endothelium and nitration of p190A. (a) S-nitrosylation of β- and p120-catenins, and p190A. Proteins were co-immunoprecipitated with specific Abs, and precipitates were probed with HRP-avidin; results of two independent experiments are shown; n = 4. Note that the β-catenin band is indicated by an arrow. SNO of β-catenin in VEGF-treated cells is a positive control. Molecular mass standards are indicated next to the gel blots in kilodaltons. (b) The bar plot shows nitrite accumulation in the presence of SOD and TEMPOL; mean ± SEM (error bars); *, P < 0.05 as compared with Wt control; n = 4. (c) Bar plot shows the fluorescence emission of EOH at 580 nm; mean ± SEM (error bars); *, P < 0.05 as compared with Wt control; n = 4. (d) β- and p120-catenins and (e) p190A were co-immunoprecipitated with specific Abs, and precipitates were probed for nitrotyrosine (3-N). Results of two independent experiments are shown; n = 4. (e) Cav-1 deletion induced the nitration of p190A, which was reduced by TEMPOL treatment and in cells isolated from lungs of Cav-1/eNOS double knockout mice (DKO). (e, right) Bar plot; fold increase in p190A nitration normalized to p190A loading; mean ± SEM (error bars); *, P < 0.05 as compared with Wt; n = 4.