VGL Cl: Voltage-gated chloride channels

Abstract

This chapter discusses the voltage-gated (VLG) chloride (Cl) channels. This category of voltage-gated Cl– channels includes the channels in which open probability shows a strong dependence on the membrane voltage or for which changes in the membrane potential represent the primary regulatory mechanism. The physiological functions of the voltage-gated Cl– channels vary in different tissues. The ClC-0 and ClC-1 channels stabilize the membrane potential in the electric organ of Torpedo and in skeletal muscle cells, respectively. In skeletal muscle cells, the activity of the ClC-1 channel ensures the electrical stability of the excitable membrane. The widely expressed ClC-2 channel is activated by unphysiologically strong hyperpolarization and by extracellular hypotonicity. The physiological role of this channel is to contribute to a regulatory volume decrease in a wide range of cell and tissue types. The chapter discusses several types of cloning methods that are used for various genes encoding for calcium channels in different organisms. The tissue distribution of mRNAs encoding members of the ClC family of chloride channels along with their phenotypic expression and sequence analysis is also presented in the chapter.