MOLECULAR-CHARACTERIZATION AND FUNCTIONAL-CHARACTERIZATION OF A RAT-BRAIN K-V-BETA-3-POTASSIUM CHANNEL SUBUNIT

A novel potassium channel beta-subunit (K-v beta 3) was cloned from ra t brain being the third member of a K-v beta subunit gene family. It i s a protein of 403 amino acid residues with a 68% amino acid sequence homology to K-v beta 1.1, K-v beta 3 is primarily expressed in rat bra in having a distribution distinct to those of K-v beta 1.1 and K-v bet a 2. This subunit also has a long N-terminal structure and induces ina ctivation in N-terminal deleted K(v)1.4 but not in other members of th e K(v)1 channel family. Similarly to K-v beta 1.1, the K-v beta 3-indu ced inactivation is regulated by the intracellular redox potential.