Structure, function, and regulation of vertebrate Na+/H+ exchangers

The Na+/H+ exchangers are vital transmembrane transporters that participate in the regulation of intracellular pH and volume as well as transepithelial ion transport. Several isoforms of these antiporters belonging to the same gene family have been cloned, and they display tissue-specific expression. All these transporters are highly regulated via various stimuli, which can modulate their activity and expression level. Impairments in regulation of the antiporters may contribute to certain pathologic situations. Biochemical techniques and the tools of molecular genetics now provide the means to analyze the different aspects of these transporters at a molecular level.