Receptor sites for open channel blockers of Shaker voltage-gated potassium channels--molecular approaches.

The Shaker locus encodes a family of voltage-gated potassium (K) channels expressed in the central and peripheral nervous system as well as in muscle. Members of the Shaker K-family have variant amino- and carboxy-terminal sequences, which assemble into homo- and hetero-multimeric K-channels. The channels have distinct kinetics of activation and inactivation. Electrophysiological characterization of wild type and mutant K-channels allows to correlate particular domains and critical amino acid residues with receptor sites of open channel blockers such as tetraethylammonium, charybdotoxin and dendrotoxin.