Potassium channel subunit that does not form functional channels by itself. Can form functional heterotetrameric channels with KCNB1; modulates the delayed rectifier voltage-gated potassium channel activation and deactivation rates of KCNB1 .
Subcellular locations: Cell membrane
Colocalizes with KCNB1 at the plasma membrane .
Expressed in brain and placenta, and at much lower levels in kidney and pancreas .