Modulation and genetic identification of the M channel

Potassium channels constitute a superfamily of the most diversified ion cha nnels, acting in delicate and accurate ways to control or modify many physi ological and pathological functions including membrane excitability, transm itter release, cell proliferation and cell degeneration. The M-type channel is a unique ligand-regulated and voltage-gated K+ channel showing distinct physiological and pharmacological characteristics. This review will cover some important progress in the study of M channel modulation, particularly focusing on membrane transduction mechanisms. The K+ channel genes correspo nding to the M channel have been identified and will be reviewed in detail. It has been a long journey since the discovery of M current in 1980 to our present understanding of the mysterious mechanisms for M channel modulation a journey which exemplifies tremendous achievements in ion channel researc h and exciting discoveries of elaborate modulatory systems linked to these channels. While substantial evidence has accumulated, challenging questions remain to be answered. (C) 2000 Elsevier Science Ltd. All rights reserved.