Molecular cloning of a mercurial-insensitive water channel expressed in selected water-transporting tissues.

摘要: Two mercurial-inhibitable water-transporting proteins have been identified: CHIP28, an erythrocyte water channel also expressed in kidney tubules and selected extrarenal epithelia, WCH-CD, a collecting duct channel. In searching for protein responsible the high transcellular permeability lung alveolus, we cloned 32-kDa (mercurial-insensitive (MIWC)) from rat cDNA library with several novel features. Water was strongly increased Xenopus oocytes expressing MIWC mercurial-insensitive manner, contrast to known channels. By situ hybridization, showed unique distribution cells that do not express including papillary vasa recta, lining subarachnoid space ventricles brain, inner nuclear layer retina, conjunctival epithelium. An alternatively spliced form of 165-base pair deletion coding sequence identified; relative expression mRNA tissue-specific. The may participate urinary concentrating mechanism, absorption cerebrospinal fluid, other physiological processes.