PRIMARY STRUCTURE AND FUNCTIONAL-CHARACTERIZATION OF A HIGH-AFFINITY GLUTAMATE TRANSPORTER
PRIMARY STRUCTURE AND FUNCTIONAL-CHARACTERIZATION OF A HIGH-AFFINITY GLUTAMATE TRANSPORTER
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DOI：
10.1038/360467a0
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发表时间：
1992-12-03
期刊：
影响因子：
64.8
通讯作者：
HEDIGER, MA
中科院分区：
文献类型：
--
作者：
KANAI, Y;HEDIGER, MA
谷氨酸盐通过高亲和力和低亲和力运输系统跨过小肠和肾脏的神经元、神经胶质细胞和上皮细胞的质膜运输1-5。高亲和力 (K(m) 2-50 muM) 转运系统已被描述1,6,7，其依赖于 Na+ 而不是 Cl- 离子，并且偏爱 L-谷氨酸和 D- 和 L-天冬氨酸。在神经元中，高亲和力谷氨酸转运蛋白对于通过快速去除突触间隙释放的谷氨酸来终止谷氨酸的突触后作用至关重要6,7。我们通过在非洲爪蟾卵母细胞中的表达，从兔小肠中分离出了编码一种电生Na+-而非Cl-依赖性高亲和力谷氨酸转运蛋白（命名为EAAC1）的互补DNA。我们在中枢神经系统以及小肠、肾脏、肝脏和心脏的特定神经元结构中发现了 EAAC1 转录本。表达蛋白的功能和药理学是神经元组织中已鉴定的高亲和力谷氨酸转运蛋白的特征。与某些神经退行性疾病相关的谷氨酸转运异常，以及在缺血和缺氧期间发生的谷氨酸转运异常可能是由于该蛋白质的功能异常所致。
GLUTAMATE transport across plasma membranes of neurons, glial cells and epithelial cells of the small intestine and kidney proceeds by high- and low-affinity transport systems1-5. High-affinity (K(m) 2-50 muM) transport systems have been described1,6,7 that are dependent on Na+ but not Cl- ions and have a preference for L-glutamate and D- and L-aspartate. In neurons high-affinity glutamate transporters are essential for terminating the postsynaptic action of glutamate by rapidly removing released glutamate from the synaptic cleft6,7. We have isolated a complementary DNA encoding an electrogenic Na+- but not Cl--dependent high-affinity glutamate transporter (named EAAC1) from rabbit small intestine by expression in Xenopus oocytes. We find EAAC1 transcripts in specific neuronal structures in the central nervous system as well as in the small intestine, kidney, liver and heart. The function and pharmacology of the expressed protein are characteristic of the high-affinity glutamate transporter already identified in neuronal tissues. The abnormal glutamate transport that is associated with certain neurodegenerative diseases8 and which occurs during ischaemia and anoxia7 Could be due to abnormalities in the function of this protein.