Regulation of the epithelial sodium channels (ENaC) by small G proteins and phosphatidylinositides

The epithelial Na⁺ channel (ENaC) plays a central role in control of epithelial surface hydration and vascular volume. ENaC activity in these epithelia is limiting for sodium reabsorption. Abnormalities in ENaC function have been linked to disorders of total body Na⁺ homeostasis, blood volume, blood pressure, and lung fluid balance. Recently, ion channels were recognized as physiologically important effectors of small GTP-binding proteins and phosphatidylinositides. We review here recent findings relevant to regulation of ENaC by small G proteins and phosphatidylinositides.