Na+/K+-ATPase is an integral membrane protein complex that is responsible for the ATP-dependent transport of sodium and potassium across the cell membrane. Na+/K+-ATPase hydrolyzes ATP to maintain the transmembrane gradients of Na+ and K+. The Na+/K+-ATPase consists of a large transmembrane catalytic subunit, termed the a subunit, and an associated smaller glycoprotein, termed the ß subunit, that appears to be necessary for the assembly and transport of the sodium pump to the plasma membrane. There are three isoforms of the a subunit (a-1, -2, and -3) and two isoforms of the ß subunit (ß-1 and -2) encoded by two multigene families. The a-1 and ß mRNAs are present in all cell types examined, whereas the a-2 and a-3 mRNAs exhibit a more restricted pattern of cell-specific expression. The a subunit protein has been found in kidney, brain (both neuronal and non-neuronal cells), heart, and to a lesser extent liver, skeletal and smooth muscle.Synonyms: Na(+)/K(+) ATPase alpha-1 subunit, Sodium pump ATPase subunit alpha-1, Sodium/potassium-transporting ATPase subunit alpha-1