Modulation of Kv Channel α/β Subunit Interactions

Voltage-gated K⁺ channels comprise the largest and most diverse class of ion channels. These channels establish the resting membrane potential and modulate the frequency and duration of action potentials in nerve and muscle, as well as being the targets of several antiarrhythmic drugs in the heart. The multiplicity of Kv channel function is further enhanced through modulation by accessory β subunits, which confer rapid inactivation, alter current amplitudes, and promote cell surface expression. In addition, α/β interactions are also influenced by second messenger pathways. Recent evidence demonstrates that phosphorylation of Kv channel α and/or β subunits may dramatically affect channel properties. The functional response of different K⁺ channel subunits to activation of protein kinases represents not only a means to modulate subunit interactions, but also another mechanism for K⁺ channel diversity in vivo.