Figure 5.

Rac1, a subcomponent of NOX, is activated upon OA-Alb exposure at pH 6.4. (A) HK-2 cells were stimulated with OA-Alb (15 g/L) at pH 6.4 for the indicated times. The amount of GTP-bound active Rac1 was assessed using a glutathione-S-transferase (GST) pull-down assay with p21 activated kinase 1(PAK)-p21 binding domain (PBD) GST-fusion beads followed by immunoblotting with an anti-Rac1 antibody. GTP-bound active Rac1 increased in a time-dependent manner. (B) Quantification of GTP-bound active Rac1 normalized to total Rac1 levels. The total level of Rac1 did not change over time. The data are expressed as the mean ± SEM of three independent experiments. The statistical significance of the difference is indicated (*P < 0.05).