Pore-forming (alpha) subunit of voltage-gated rapidly inactivating A-type potassium channels. May contribute to I(To) current in heart and I(Sa) current in neurons. Channel properties are modulated by interactions with other alpha subunits and with regulatory subunits.
[1]"Gene structures and expression profiles of three human KCND (Kv4) potassium channels mediating A-type currents I(TO) and I(SA)."Isbrandt D., Leicher T., Waldschuetz R., Zhu X.-R., Luhmann U., Michel U., Sauter K., Pongs O.Genomics 64:144-1