Figure 1.

Acid incubation induces Pyk2 phosphorylation in OKP cells. After growing to confluence, cells were rendered quiescent for 48 hours and then exposed to a medium of pH 7.4 (control) or 6.8 (acid) for the indicated time. Pyk2 was then immunoprecipitated and phosphorylation assayed, as described in Methods. Data are plotted as percentage of control; n = 6 for control and acid at each time point. Pyk2 phosphorylation was increased in 4 of 6 experiments (15 seconds), 6 of 6 experiments (30 seconds and 5 minutes), 5 of 6 experiments (90 seconds), and 2 of 6 experiments (10 minutes).