Sodium/potassium-transporting ATPase subunit alpha-2 is a protein which in humans is encoded by the ATP1A2 gene. The protein encoded by this gene belongs to the family of P-type cation transport ATPases and to the subfamily of Na+/K+-ATPases. Na+/K+-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+/K+-ATPase is encoded by multiple genes. This gene encodes an alpha 2 subunit.