Chloride channels belong to a superfamily of ion channels that permit passive passage of anions, mainly chloride, across cell membrane. Chloride channels perform important roles in the regulation of cellular excitability, in transepithelial transport, cell volume regulation, and acidification of intracellular organelles. Chloride channels represent a group of potential drug targets.
The chloride channel protein (ClC) family comprises both chloride (Cl-) channels and chloride/proton (Cl-/H+) antiporters. In prokaryotes and eukaryotes, these proteins mediate the movement of Cl- ions across the membrane. In eukaryotes, ClC proteins play a role in the stabilization of membrane potential, epithelial ion transport, hippocampal neuroprotection, cardiac pacemaker activity and vesicular acidification.