New tricks for old dogs: KCNQ expression and role in smooth muscle

Ion channels encoded by the KCNQ gene family (K(v)7.1-7.5) are major determinants of neuronal membrane potential and the cardiac action potential. This key physiological role is highlighted by the existence of a number of hereditary disorders caused by mutations to KCNQ genes. Recently, KCNQ gene expression has been identified in vascular and non-vascular smooth muscles. In addition, experiments with an array of pharmacological modulators of KCNQ channels have supported a crucial role for these channels in regulating smooth muscle contractility. This article will provide an overview of present understanding in this nascent area of KCNQ research and will offer guidance as to future directions.