ATPase Na+/K+ transporting subunit alpha 1 (ATP1A1) Homo sapiens 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 1 subunit. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, May 2009],