Sodium channel protein type 4 subunit alpha (SCN4A)

This protein mediates the voltage-dependent sodium ion permeability of excitable membranes. Assuming opened or closed conformations in response to the voltage difference across the membrane, the protein forms a sodium-selective channel through which Na(+) ions may pass in accordance with their electrochemical gradient.

This sodium channel may be found in both denervated and innervated skeletal muscle. .