Sodium/potassium-transporting ATPase subunit alpha-1 is an enzyme that in humans is encoded by the ATP1A1 gene.
The protein encoded by this gene belongs to the family of P-type cation transport ATPases, and to the subfamily of Na<sup>+</sup>/K<sup>+</sup>-ATPases. Na<sup>+</sup>/K<sup>+</sup>-ATPase is an integral membrane protein responsible for establishing and maintaining the electrochemical gradients of Na and K ions across the plasma membrane. These gradients are essential for osmoregulation, for sodium-coupled transport of a variety of organic and inorganic molecules, and for electrical excitability of nerve and muscle. This enzyme is composed of two subunits, a large catalytic subunit (alpha) and a smaller glycoprotein subunit (beta). The catalytic subunit of Na<sup>+</sup>/K<sup>+</sup>-ATPase is encoded by multiple genes. This gene encodes an alpha 1 subunit. Alternatively spliced transcript variants encoding different isoforms have been identified.
In melanocytic cells ATP1A1 gene expression may be regulated by MITF.
Mutations in this gene have been associated with aldosterone-producing adenomas and secondary hypertension.