ether-à-go-go related potassium channel
Definition A potassium channel (potassium voltage-gated channel—subfamily H (Eag-related)—member, OMIM:152427, UniProtKB:Q12809) encoded by KCNH2* that plays a critical role in cardiac action potential repolarisation, mutations of which reduce hERG conductance, and surface expression cause congenital long QT syndrome–LQTS.
Acquired LQTS results when the channel is inhibited by various small molecules, many of which are non-cardiac drugs–e.g., astemizole, cisapride, droperidol, grepafloxacin, and terfenadine, which were withdrawn from the market for this reason. Small molecules that increase hERG current (hERG activators) may be of value in treating LQTS. Candidate hERG activators include mallotoxin–an extract of the tree Mallotus phillippinensis and a number of synthetic compounds.
*Formerly known as HERG (human Ether-à-go-go-Related Gene
References Acta Pharmacologica Sinica (2011) 32: 781–788;
doi: 10.1038/aps.2011.70; published online 30 May 2011