Molecular cloning of a mercurial-insensitive water channel expressed in selected water-transporting tissues.
Molecular cloning of a mercurial-insensitive water channel expressed in selected water-transporting tissues.
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DOI：
10.1016/s0021-9258(17)37486-0
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发表时间：
1994-02
期刊：
影响因子：
--
通讯作者：
H. Hasegawa;T. Ma;W. Skach;M. Matthay;A. Verkman
中科院分区：
文献类型：
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作者：
H. Hasegawa;T. Ma;W. Skach;M. Matthay;A. Verkman
已鉴定出两种汞抑制性水转运蛋白：CHIP28（一种红细胞水通道，也在肾小管和选定的肾外上皮细胞中表达）和 WCH-CD（一种肾集合管水通道）。在寻找负责肺泡高跨细胞水渗透性的蛋白质时，我们从大鼠肺 cDNA 文库中克隆了一个 32 kDa 的水通道（汞不敏感水通道 (MIWC)），该通道具有几个新特征。与已知的水通道相比，以对汞不敏感的方式表达 MIWC 的非洲爪蟾卵母细胞的水渗透性显着增加。通过原位杂交，MIWC 在不表达 CHIP28 的细胞中显示出独特的分布，包括肾乳头血管直肠、脑中蛛网膜下腔和脑室的细胞、视网膜的内核层和结膜上皮。 MIWC 的另一种剪接形式也被鉴定出来，其编码序列中存在 165 个碱基对的缺失；剪接的 mRNA 的相对表达具有组织特异性。 MIWC水通道可能参与尿液浓缩机制、脑脊液吸收等生理过程。
Two mercurial-inhibitable water-transporting proteins have been identified: CHIP28, an erythrocyte water channel also expressed in kidney tubules and selected extrarenal epithelia, and WCH-CD, a kidney collecting duct water channel. In searching for a protein responsible for the high transcellular water permeability in lung alveolus, we cloned a 32-kDa water channel (mercurial-insensitive water channel (MIWC)) from a rat lung cDNA library with several novel features. Water permeability was strongly increased in Xenopus oocytes expressing MIWC in a mercurial-insensitive manner, in contrast to known water channels. By in situ hybridization, MIWC showed an unique distribution in cells that do not express CHIP28, including kidney papillary vasa recta, cells lining the subarachnoid space and ventricles in brain, the inner nuclear layer in retina, and the conjunctival epithelium. An alternatively spliced form of MIWC with a 165-base pair deletion in the coding sequence was also identified; relative expression of the spliced mRNA was tissue-specific. The MIWC water channel may participate in the urinary concentrating mechanism, the absorption of cerebrospinal fluid, and other physiological processes.