Molecular 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 rat brain being the third member of a K-v beta subunit gene family. It is 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 brain having a distribution distinct to those of K-v beta 1.1 and K-v beta 2. This subunit also has a long N-terminal structure and induces inactivation in N-terminal deleted K(v)1.4 but not in other members of the K(v)1 channel family. Similarly to K-v beta 1.1, the K-v beta 3-induced inactivation is regulated by the intracellular redox potential.