Copper-transporting ATPase 1 is an integral membrane protein cycling constitutively between the trans-golgi network and the plasma membrane. It may supply copper to copper-requiring proteins within the secretory pathway, when localized in the trans-golgi network. Under conditions of elevated extracellular copper, it relocalized to the plasma membrane where it functions in the efflux of copper from cells. Defects in ATP7A are the cause of Menkes syndrome; also known as kinky hair disease, an X-