Physiological Properties of hERG 1a/1b Heteromeric Currents and a hERG 1b-Specific Mutation Associated With Long-QT Syndrome.

The article discusses a study on the currents produced by hERG 1a and 1a/1b channels expressed in HEK-293 cells in relation to long-QT syndrome. It was found that hERG 1a currents are smaller than heteromeric hERG 1a/1b currents. This finding is said to correspond with a 2-fold increase in the rates of activation and recovery from inactivation. Also, It was observed that mutations disrupting hERG 1b function can reduce cardiac I_Kr and increase drug sensitivity.