Fischbarg J, Kuang K Y, Vera J C, Arant S, Silverstein S C, Loike J, Rosen O M
Department of Physiology, College of Physicians and Surgeons, Columbia University, New York, NY 10032.
Proc Natl Acad Sci U S A. 1990 Apr;87(8):3244-7. doi: 10.1073/pnas.87.8.3244.
Water traverses the plasma membranes of some eukaryotic cells faster than can be explained by the water permeability of their lipid bilayers. This has led to a search for a water channel. Our previous work identified glucose transporters as candidates for such a channel. We report here that Xenopus laevis oocytes injected with mRNA encoding the brain/Hep G2, adult skeletal muscle/adipocyte, or liver forms of the glucose transporter exhibit an osmotic water permeability of their plasma membranes larger than that of untreated oocytes. The osmotic water permeability component attributable to glucose transporters increased an average of 4.8-fold in the injected oocytes. These studies provide direct evidence that the facilitative, sodium-independent mammalian glucose transporters serve as membrane water channels.
水穿过某些真核细胞的质膜的速度比根据其脂质双层的水渗透性所能解释的速度要快。这引发了对水通道的寻找。我们之前的研究工作将葡萄糖转运蛋白确定为这种通道的候选者。我们在此报告，注射了编码脑/肝癌细胞系Hep G2、成年骨骼肌/脂肪细胞或肝脏形式的葡萄糖转运蛋白的mRNA的非洲爪蟾卵母细胞，其质膜的渗透水通透性比未处理的卵母细胞大。在注射的卵母细胞中，归因于葡萄糖转运蛋白的渗透水通透性成分平均增加了4.8倍。这些研究提供了直接证据，表明促进性的、不依赖钠的哺乳动物葡萄糖转运蛋白可作为膜水通道。
