HERG K+ channels: friend and foe

The K+ channel encoded by the human ether-a-go-go related gene (HERG) is on e of many ion channels that are crucial for normal action potential repolar ization in cardiac myocytes, HERG encodes the pore-forming subunit of the r apid component of the delayed rectifier K+ channel, I-K(Vr). HERG K+ channe ls are of considerable pharmaceutical interest as possible therapeutic targ ets for anti-arrhythmic agents and as the molecular target responsible for the cardiac toxicity of a wide range of pharmaceutical agents. Recent studi es of the molecular basis of the promiscuity of HERG K+ channel drug bindin g has not only started to shed light on this tricky pharmaceutical problem but has also provided further insights into the structure and function of H ERG K+ channels.