Voltage-gated K+ channels represent a structurally and functionally diverse group of membrane proteins. These channels establish the resting membrane potential and modulate the frequency and duration of action potentials in nerve and muscle1. The duration of the open states of K+ channels is determined by the rates of deactivation and inactivation. KV channels are hetero-oligomeric complexes consisting of two different types of subunits: membrane-bound, pore-forming α subunits and the smaller β subunits. The β subunits appear to be peripheral proteins tightly associated with the cytoplasmic side of the α subunits2.
The inactivation gate can be formed by an N-terminal segment of an auxiliary β-subunit, as in the complex of KVβ1 and KVα family channels3. There are three mammalian KVβ genes: KVβ1, KVβ2 and KVβ3. Additional variability in the KVβ1 family results from alternative splicing in the amino terminal region, thus yielding the KVβ1.1, KVβ1.2, and KVβ1.3 subunits4.
