title: A chloride channel widely expressed in epithelial and non-epithelial cells.
abstract: Chloride channels have several functions, including the regulation of cell volume, stabilizing membrane potential, signal transduction and transepithelial transport. The plasma membrane Cl- channels already cloned belong to different structural classes: ligand-gated channels, voltage-gated channels, and possibly transporters of the ATP-binding-cassette type (if the cystic fibrosis transmembrane regulator is a Cl- channel). The importance of chloride channels is illustrated by the phenotypes that can result from their malfunction: cystic fibrosis, in which transepithelial transport is impaired, and myotonia, in which ClC-1, the principal skeletal muscle Cl- channel, is defective. Here we report the properties of ClC-2, a new member of the voltage-gated Cl- channel family. Its sequence is approximately 50% identical to either the Torpedo electroplax Cl- channel, ClC-0 (ref. 8), or the rat muscle Cl- channel, ClC-1 (ref. 9). Isolated initially from rat heart and brain, it is also expressed in pancreas, lung and liver, for example, and in pure cell lines of fibroblastic, neuronal, and epithelial origin, including tissues and cells affected by cystic fibrosis. Expression in Xenopus oocytes induces Cl- currents that activate slowly upon hyperpolarization and display a linear instantaneous current-voltage relationship. The conductivity sequence is Cl- greater than or equal to Br- greater than I-. The presence of ClC-2 in such different cell types contrasts with the highly specialized expression of ClC-1 (ref. 9) and also with the cloned cation channels, and suggests that its function is important for most cells.
authors.affiliation: Centre for Molecular Neurobiology (ZMNH), Hamburg University, Hamburg, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Thiemann
authors.forename: S
authors.initials: S
authors.lastname: Gründer
authors.forename: M
authors.initials: M
authors.lastname: Pusch
authors.forename: T J
authors.initials: TJ
authors.lastname: Jentsch
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D000090007:CLC-2 Chloride Channels; D002460:Cell Line; D018118:Chloride Channels / Q000737:chemistry / Q000235:genetics* / Q000502:physiology; D002712:Chlorides / Q000378:metabolism*; D004553:Electric Conductivity; D006801:Humans; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics* / Q000502:physiology; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000737:chemistry / Q000235:genetics* / Q000502:physiology; D051381:Rats
chemical_list: D000090007:CLC-2 Chloride Channels; D018118:Chloride Channels; D002712:Chlorides; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins