Ha-ras activates the Na super(+)/H super(+) antiporter by a protein kinase C-independent mechanism

In quiescent Ha-ras -transfected NIH 3T3 cells, addition of serum growth factors, bombesin or 12-O-tetradecanoylphorbol-13-acetate (TPA) leads to a dimethylamiloride-sensitive intracellular alkalinization, which can be inhibited by staurosporine, a potent inhibitor of protein kinase C. Expression of the transforming Ha-ras gene causes a growth factor-independent increase in cytoplasmic pH. This Ha-ras -induced alkalizination is sensitive to dimethylamiloride but is not affected by staurosporine concentrations which prevent the pH response after addition of growth factors or TPA.