Potassium Voltage Gated Channel Subfamily H, Member 3 (KCNH3)

KCNH3 shares 95% amino acid sequence identity with rat Kcnh3, 48% identity with human BEC2 (KCNH4), 46% identity with rat Elk, 33% similarity with human ERG, and 30% similarity with rat Eag. The authors concluded that KCNH3, BEC2, and Elk form a subfamily within the eag family. Expression of recombinant KCNH3 in mammalian cells induced a voltage-gated outward current with a fast inactivation component. This current was insensitive to tetraethylammonium and quinidine. Northern blot analysis of human tissues detected a major 4-kb KCNH3 transcript in brain; KCNH3 expression was not found in any other tissue examined. Within brain, KCNH3 was expressed in cortical structures, such as the cerebral cortex, amygdala, and hippocampus, and in the striatal regions, including the putamen and caudate nucleus.