Mathematical Biology seminar Mike Sanguinetti Dept of Physiology and CVRTI "Gating and block of cardiac hERG potassium channels" October 5, 2005 3:05pm, LCB 215 Many potassium-selective ion channels mediate repolarization of the cardiac myocyte action potential. Our laboratory uses molecular biology and biophysical techniques to study the mechanisms and structural basis of how these channels open and close in response to changes in transmembrane potential and how the channels are blocked by drugs. Most of our work is focused on the hERG potassium channel. Drug block of hERG channels or mutations in the gene that encodes the channel causes long QT syndrome, a disorder of ventricular repolarization that predisposes affected individuals to lethal heart rhythms. In this talk, the basic properties of hERG channel gating (opening and closing of the K+-selective pore) will be presented, followed by an in-depth molecular analysis of channel gating modification/block by divalent cations and commonly prescribed drugs.