Two potassium currents, IKs and IKr, provide the principal repolarising currents in cardiac myocytes for the termination of action potentials. The potassium voltage-gated channel subfamily H member 2 (KCNH2 aka HERG) is the pore-forming alpha subunit of a stable complex with a regulating beta subunit of the potassium voltage-gated channel subfamily E family (KCNE). This stable complex creates the Kr current by the efflux of K+ (Macdonald et al. 1997, Abbott et al. 1999).
delayed rectifier potassium channel activity of KCNH2:KCNE [plasma membrane]