ALTERNATIVE SPLICING OF THE HUMAN SHAKER K+ CHANNEL BETA-1 GENE AND FUNCTIONAL EXPRESSION OF THE BETA-2 GENE-PRODUCT

Mammalian voltage-activated Shaker K+ channels associate with at least three cytoplasmic proteins: Kv beta 1, Kv beta 2 and Kv beta 3. These beta subnunits contain variable N-termini, which can modulate the inactivation of Shaker alpha subunits, but are homologous throughout an aldo-keto reductase core. Human and ferret beta 3 proteins are identical with rat beta 1 throughout the core while beta 2 proteins are not; beta 2 also contains a shorter N-terminus and has no reported physiological role, We report that human beta 1 and beta 3 are derived from the same gene and that beta 2 modulates the inactivation properties of Kv1.4 alpha subunits.