Electrophysiological characterization of the Drosophila ERG K+ channel

Mutations that exist in voltage-gated ion channels are associated with diseases, including epilepsy and cardiac arrhythmia. These conditions are attributed to the misfiring or improper functioning of electrically excitable cells, such as neurons or cardiac muscle cells. One particular channel that has been identified to play a role in both cardiac arrhythmia and seizures is the ether-a-go-go potassium channel, which has been identified in a variety of organisms. This channel is a voltage-gated K+ channel involved in repolarization of excitable cells. When the channel is mutated it can display a vast array of effects upon these excitable cells. The Drosophila homolog of ERG (DERG) is a novel protein that requires co-expression of the down and out protein for proper functional expression in cells. Interestingly, Drosophila erg and human erg exhibit highly similar structural features. We are interested in using the Drosophila erg homolog for further characterization of this ion channel type. In particular, this study examined the expression of a previously identified mutant erg (DERG-GA) and dao proteins in transgenic flies and the impact on behavioral phenotypes. Additionally, heterologous coexpression of either Drosophila erg wild-type or mutant subunits with dao were performed to characterize the electrophysiological properties of the Drosophila erg mutant and wild-type potassium channel currents