Potassium Inwardly Rectifying Channel Subfamily J, Member 8 (KCNJ8)

Inagaki et al. (1995) isolated a cDNA from a rat pancreatic islet cell library that encodes a member of the inward rectifier potassium channel family. The predicted 424-amino acid protein, which they designated uKATP-1, has 2 transmembrane domains and shares 43 to 46% identity with other inward rectifier potassium channels, including ROMK1, IRK1, GIRK1, and cKATP-1. When the protein was expressed in Xenopus oocytes, a weak rectifier activity was demonstrated that was blocked with Ba(+2) and activated by diazoxide. Northern blots showed that the mRNA is widely expressed in various tissues of the rat. Inagaki et al. (1995) cloned the human gene, designated KCNJ8. The predicted human protein is 98% identical to that of the rat.