Ito channels are octomeric complexes with four subunits of each Kv4.2 and K+ channel-interacting protein 2

Mammalian voltage- gated K (+) channels are assemblies of pore- forming alpha- subunits and modulating beta- subunits. To operate correctly, Kv4 alpha- subunits in the heart and central nervous system require recently identified beta- subunits of the neuronal calcium sensing protein family called K (+) channel- interacting proteins ( KChIPs). Here, Kv4.2 . KChIP2 channels are purified, integrity of isolated complexes confirmed, molar ratio of the subunits determined, and subunit valence established. A complex has 4 subunits of each type, a stoichiometry expected for other channels employing neuronal calcium sensing beta- subunits.