Pore-forming (alpha) subunit of voltage-gated inwardly rectifying potassium channel. Channel properties are modulated by cAMP and subunit assembly (By similarity). Regulates the movements of the male's copulatory spicules before and during male mating behavior (PubMed:12684455). The potassium channel is composed of a homo- or heterotetrameric complex (PubMed:27916661). Interacts with dnj-1; dnj-1 chaperone promotes tetramerization (PubMed:27916661). Belongs to the potassium channel family. H (Eag) (TC 1.A.1.20) subfamily. Kv11.1/KCNH2 sub-subfamily.