This gene encodes an integral membrane protein that comprises a subunit of an ATP-metabolizing enzyme responsible for transporting sodium and potassium ions across the plasma membrane. This enzyme regulates the electrochemical gradient of these ions in cells, and plays a central role in osmoregulation and signal transmission in nerves and muscles, among other biological processes. The encoded protein is the non-catalytic beta subunit; it works together with a catalytic alpha subunit and a gamma subunit. [provided by RefSeq, Mar 2013]