Voltage-gated potassium (Kv) channels are key components of the potassium currents in the heart and central nervous system. In the heart, Kv4 channels are involved in the repolarization phase of the action potential. In the brain however, these channels prevent reverse-propagation of action potentials. Found associated with Kv4 channels are a group of calcium-binding proteins termed KChIPs (Kv channel interacting proteins).