INACTIVATION PROPERTIES OF VOLTAGE-GATED K-SUBUNIT( CHANNELS ALTERED BY PRESENCE OF BETA)

Structural and functional diversity of voltage-gated K(v)1-type potass ium channels in rat brain is enhanced by the association of two differ ent types of subunits, the membrane-bound, pore-forming alpha-subunits and a peripheral beta-subunit. We have cloned a beta-subunit (K-v bet a 1) that is specifically expressed in the rat nervous system. Associa tion of K-v beta 1 with alpha-subunits confers rapid A-type inactivati on on non-inactivating K(v)1 channels (delayed rectifiers) in expressi on systems in vitro. This effect is mediated by an inactivating ball d omain in the K-v beta 1 amino terminus.