Sodium/Hydrogen Exchanger 8 (NHE8)

Sodium-hydrogen exchangers (NHEs), such as SLC9A8, are integral transmembrane proteins that exchange extracellular Na+ for intracellular H+. NHE8 has an N-terminal hydrophobic domain with 10 to 12 transmembrane segments and a short C-terminal hydrophilic tail. It also has 4 potential N-glycosylation sites, a PKC-epsilon (PRKCE) phosphorylation site, and putative SH2-, SH3-, ERK-, and type III PDZ-binding domains. Northern blot analysis of mouse tissues revealed ubiquitous expression, with highest levels in kidney, testis, skeletal muscle, and liver. Western blot analysis detected Nhe8 in apical membranes purified from rat renal cortex. In situ hybridization of rat kidney revealed high expression of Nhe8 in proximal tubules in the outer stripe of the outer medulla, with lower expression in cortical proximal tubules.