The sodium-potassium pump uses energy from ATP to pump sodium ions out of cells and potassium ions into cells against their concentration gradients in order to maintain cell membrane potentials and regulate cell volume and signaling. It is an integral membrane protein composed of alpha and beta subunits that uses the energy of ATP hydrolysis to change conformations and transport ions in alternating exposures of ion binding sites to either side of the membrane. The pump can be regulated endogenously through factors like cAMP levels or pharmacologically through drugs, and plays critical roles in maintaining the resting potential of neurons and other cells.