FunctionInvolved in pH regulation to eliminate acids generated by active metabolism or to counter adverse environmental conditions. Major proton extruding system driven by the inward sodium ion chemical gradient. Plays an important role in signal transduction.
Sequence similaritiesBelongs to the monovalent cation:proton antiporter 1 (CPA1) transporter (TC 2.A.36) family.
Post-translational modificationsPhosphorylated by PKA, which inhibits activity.
Cellular localizationMembrane. In intestinal epithelial cells, localizes to the ileal brush border.