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Chloride channels are a superfamily of poorly understood ion channels for chloride. Several families of voltage-gated channels and ligand-gated channels (e.g., the CaCC families) have been characterized in humans. Voltage-gated chloride channels display a variety of important physiological and cellular roles that include regulation of pH, volume homeostasis, organic solute transport, cell migration, cell proliferation and differentiation. Based on sequence homology the chloride channels can be subdivided into a number of groups. The importance of one such group, the CLC family of chloride channels, can be seen from the diseases that develop when the channel does not function normally. The CLC family of chloride channels contains 10 or 12 transmembrane helices. Each protein forms a single pore. It has been shown that some members of this family form homodimers. In terms of primary structure, they are unrelated to known cation channels or other types of anion channels. Three CLC subfamilies are found in animals. CLCN1 is involved in setting and restoring the resting membrane potential of skeletal muscle, while other channels play important parts in solute concentration mechanisms in the kidney (). These proteins contain two CBS domains. Chloride channels are also important for maintaining safe ion concentrations within plant cells. ==Pathology== Bartter's syndrome, which is associated with renal salt wasting and hypokalemic alkalosis, is due to the defective transport of chloride ions and associated ions in the thick ascending loop of Henle. CLCNKB has been implicated. Another inherited disease that affects the kidney organs is Dent's Disease, characterised by low molecular weight proteinuria and hypercalciuria where mutations in CLCN5 are implicated. Thomsen disease is associated with dominant mutations and Becker disease with recessive mutations in CLCN1. Cystic fibrosis is caused by mutations in the CFTR gene, which prevents the proper folding of the protein and subsequent degradation, resulting in decreased numbers of chloride channels in the body. This causes the buildup of mucus in the body and chronic infections. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「chloride channel」の詳細全文を読む スポンサード リンク
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