The ubiquitously expressed sodium/potassium-ATPase (Na+/K+-ATPase) exists as a oligomeric plasma membrane complex that couples the hydrolysis of one molecule of ATP to the importation of three Na+ ions and two K+ ions against their respective electrochemical gradients. As a member of the P-type family of ion motives, Na+/K+-ATPase plays a critical role in maintaining cellular volume, resting membrane potential and Na+-coupled solute transport. Multiple isoforms of three subunits, (alpha), (beta) and (gamma), comprise to form the Na+/K+-ATPase oligomer. The (alpha) subunit contains the binding sites for ATP and the cations; the glycosylated (beta) subunit ensures correct folding and membrane insertion of the (alpha) subunits. The small (gamma) subunit co-localizes with the (alpha) subunit in nephron segments, where it increases the affinity of Na+/K+-ATPase for ATP.