Wells R G, Pajor A M, Kanai Y, Turk E, Wright E M, Hediger M A
Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts 02115.
Am J Physiol. 1992 Sep;263(3 Pt 2):F459-65. doi: 10.1152/ajprenal.1992.263.3.F459.
We have used low-stringency screening with the human intestinal Na(+)-glucose cotransporter SGLT1 to isolate a 2,271-nucleotide cDNA (Hu14) from human kidney. This clone, which encodes a 672-residue protein, is 59% identical at the amino acid level to SGLT1 and has a similar number and arrangement of predicted membrane-spanning regions. It also shares significant sequence identity with other Na(+)-coupled transporters. Northern blot analysis suggests strong expression of Hu14 in kidney, but, unlike SGLT1, no significant expression in intestine. We have been unable to demonstrate definitive transport of any of a number of substrates (including amino acids, sugars, nucleosides, and vitamins) into Hu14 cRNA-injected Xenopus oocytes, although sequence conservation makes it likely that Hu14 represents another member of the Na+ cotransporter family, possibly a second Na(+)-glucose cotransporter.
我们利用人肠道钠-葡萄糖共转运蛋白SGLT1进行低严谨度筛选，从人肾脏中分离出一个2271个核苷酸的cDNA（Hu14）。该克隆编码一个672个残基的蛋白质，在氨基酸水平上与SGLT1有59%的同一性，并且预测的跨膜区域数量和排列相似。它与其他钠偶联转运蛋白也有显著的序列同一性。Northern印迹分析表明Hu14在肾脏中强烈表达，但与SGLT1不同，在肠道中无显著表达。尽管序列保守性表明Hu14可能是钠共转运蛋白家族的另一个成员，可能是第二个钠-葡萄糖共转运蛋白，但我们无法证明多种底物（包括氨基酸、糖、核苷和维生素）中的任何一种能被明确转运到注射了Hu14 cRNA的非洲爪蟾卵母细胞中。
