STRUCTURE AND FUNCTION OF VOLTAGE-GATED ION CHANNELS

Voltage-gated ion channels are key molecules for the generation of ele ctrical signals in cells. They are integral membrane proteins which ar e activated by a depolarized membrane potential resulting in a conform ational change, allowing ions to permeate. Voltage-gated ion channels can either be inactivated from this open state by an additional confor mational change which leads to a nonconducting state of the channel: o r they may be deactivated by a repolarized membrane potential. Followi ng the first successful cloning of voltage-gated ion channels in 1984 the combination of molecular biological and electrophysiological techn iques has been very fruitful in the investigation of the structure and function of these membrane proteins. From these studies a molecular p icture of the structural elements important for the activity of voltag e-gated ion channels has been established. This has assisted in clarif ying the molecular basis of the electrical excitability of cells.