Sodium–potassium ATPase (Na+/K+ ATPase)

Sodium–potassium ATPase (Na+/K+ ATPase) is an essential, ubiquitous transmembrane enzyme responsible for the active transport of sodium (Na+) out of and potassium (K+) into cells against their concentration gradients, powered by ATP hydrolysis. For each ATP molecule hydrolyzed, the pump exports three sodium ions and imports two potassium ions, thus maintaining crucial electrochemical gradients across the plasma membrane. The pump consists mainly of catalytic alpha and auxiliary beta (and sometimes gamma) subunits, and displays isoform-specific roles in various tissues. Besides its classical pump function, sodium–potassium ATPase is an established pharmacological target, notably for cardiac glycosides used in heart failure, and also acts as a signal transducer in multiple cell types. Dysregulation or mutation of its subunits is implicated in cardiovascular, neurological, and neoplastic diseases.

Other names

sodium–potassium pumpNa+/K+ pumpsodium–potassium adenosine triphosphataseNKA

Inhibition (by cardiac glycosides: blocks pump's activity, leading to increased intracellular sodium and enhanced cardiac contractility) - Modulation (by hormones or second messengers, changing pump expression or trafficking) - Receptor-mediated signaling (binding of ligands like ouabain triggers downstream signaling pathways)