Fig. 6

NHE1 regulates the phosphorylation status of cellular ERK1/2. ERK1/2 phosphorylation in untransfected AP-1 cells or AP-1 cells expressing WT and variant hNHE1, as indicated. Cells were stimulated or not with human recombinant EGF (100 ng/ml) for 15 min. a Representative immunoblots of p-ERK1/2 (T202/Y204 (ERK1)-T185/Y187 (ERK2) phosphorylation) and total ERK1/2 under the conditions shown. The arrows indicate ERK1 (top) and ERK2 (bottom), respectively. b Summary data from three to eight independent biological replicates per condition. Blots were scanned, and band intensities quantified using Un-Scan-IT Graph Digitizer software (Silk Scientific), as described in the “Methods”. Quantified data are shown as means with SEM error bars, normalized to those in untransfected, unstimulated AP-1 cells. *, **, and ***, p < 0.05, p < 0.01, and p < 0.001, respectively, compared to untransfected control; #, ##, and ###, p < 0.05, p < 0.01, and p < 0.001, respectively, compared to the same cells in absence of EGF. Two-way ANOVA, Holm-Šídák’s multiple comparisons test