Accessory potassium channel protein which modulates the activity of the pore-forming alpha subunit. Alters the functional properties of Kv2.2 but not Kv2.1. Forms heteromultimeric complex with alpha subunits. Strong expression in brain, with highest levels in neocortical and allocortical regions, hippocampus, olfactory bulb and cerebellum. Also strong in kidney. Weak expression in lung, skeletal muscle and heart. Alteration of functional properties of alpha subunit is mediated through N-terminal domain of beta subunit. Belongs to the shaker potassium channel beta subunit family.