Potassium channel subunit. Modulates channel activity by shifting the threshold and the half-maximal activation to more negative values (By similarity). Heterodimer with KCNB1. Does not form homomultimers (By similarity). Highly expressed in heart, in particular in right and left atrium, and detected at lower levels in the right and left ventricle. The segment S4 is probably the voltage-sensor and is characterized by a series of positively charged amino acids at every third position. Belongs to the potassium channel family. G (TC 1.A.1.2) subfamily. Kv6.2/KCNG2 sub-subfamily.