From genes to channels: normal mechanisms

Electrophysiologic remodeling is a process whereby heart disease alters the electrophysiologic properties of cardiac tissue. These alterations, in turn, can cause or exacerbate disease-related arrhythmias. Ion channels are the fundamental molecular units underlying cardiac electrophysiology, and it therefore follows that electrophysiologic remodeling represents alterations in the function or expression of genes encoding ion channels or other proteins crucial for cardiac electrophysiologic activity. This review will describe the mechanisms whereby normal function of these proteins arises from the processes of gene transcription, mRNA processing, and protein transport, post-translational modification, assembly with other proteins, and degradation. Identification of entirely novel targets for drug intervention should result from further understanding of the fundamental mechanisms underlying remodeling.