Auxiliary Subunits of Shaker-type Potassium Channels

Abstract

Voltage-gated potassium channels are important determinants of membrane excitability. This family of ion channels is composed of several classes of proteins, including the pore-forming Kvα subunits and the recently identified auxiliary Kvβ subunits. A combination of a large number of genes that encode various α subunits and β subunits and the selective formation of α–α and α–β heteromultimeric channels provides rich molecular diversity that allows for regulated functional heterogeneity in both excitable tissues and nonexcitable tissues. Because the Kvβ subunits can either upregulate or downregulate potassium currents, depending on the specific subunit combination, it is essential to understand their function at the molecular level. Furthermore, targeted changes of the Kvβ expression or disruption of certain α–β interactions could serve as a molecular basis for designing drugs and therapy to regulate excitability clinically.