Na(+)/Mg(2+) ion exchanger that acts as a predominant Mg(2+) efflux system at the plasma membrane. Transporter activity is driven by the inwardly directed electrochemical gradient for Na(+) ions, thus directly depends on the extracellular Na(+) ion concentration set by Na(+)/K(+) pump. Generates circadian cellular Mg(2+) fluxes that feed back to regulate clock-controlled gene expression and metabolism and facilitate higher energetic demands during the day (By similarity). Has a role in regulating the activity of ATP-dependent enzymes, including those operating in Krebs cycle and the electron transport chain (By similarity).
Subcellular locations: Cell membrane, Basolateral cell membrane