Kv3.3 is a member of the Shaw type family of voltage-gated K+ channels that includes four members (Kv3.1-3.4).
Kv3 subfamily members inactivate very rapidly and therefore are thought to play a role in the repolarization of action potentials and to facilitate repetitive high frequency firing.
Kv3.3 is mostly localized in the brain, although it has been observed in vascular smooth muscle cells and eye epithelium.
In the brain its expression pattern largely overlaps that of the Kv3.1 channel suggesting that they may form functional heteromers. Indeed, mouse knockouts of both Kv3.1 and Kv3.3, but not either channel alone, display severe motor defects.
