EXPRESSION CLONING OF A MAMMALIAN PROTON-COUPLED OLIGOPEPTIDE TRANSPORTER
EXPRESSION CLONING OF A MAMMALIAN PROTON-COUPLED OLIGOPEPTIDE TRANSPORTER
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DOI：
10.1038/368563a0
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发表时间：
1994-04-07
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：
FEI, YJ;KANAI, Y;HEDIGER, MA
在哺乳动物中，有机溶质跨质膜的主动运输被认为主要是由Na+梯度1-3驱动的。本文报道了兔小肠低聚肽和多肽类抗生素H+偶联转运蛋白的克隆和功能鉴定。这种名为PepT1的新蛋白质表现出不同寻常的广泛底物专一性。PepT1介导的摄取是电生的，不依赖于细胞外的Na+，K+和Cl-，也不依赖于膜电位。在肠道、肾脏和肝脏中发现了PepT1信使RNA，在脑中也有少量表达。在肠道中，PepT1途径构成了蛋白质消化产物吸收的主要机制。据我们所知，PepT1的一级结构是首次报道脊椎动物中质子偶联的有机溶质转运体，并代表了原核生物H+偶联和脊椎动物Na+偶联有机溶质转运体之间有趣的进化联系。
IN mammals, active transport of organic solutes across plasma membranes was thought to be primarily driven by the Na+ gradient1-3. Here we report the cloning and functional characterization of a H+-coupled transporter of oligopeptides and peptide-derived antibiotics from rabbit small intestine. This new protein, named PepT1, displays an unusually broad substrate specificity. PepT1-mediated uptake is electrogenic, independent of extracellular Na+, K+ and Cl-, and of membrane potential. PepT1 messenger RNA was found in intestine, kidney and liver and in small amounts in brain. In the intestine, the PepT1 pathway constitutes a major mechanism for absorption of the products of protein digestion. To our knowledge, the PepT1 primary structure is the first reported for a proton-coupled organic solute transporter in vertebrates and represents an interesting evolutionary link between prokaryotic H+-coupled and vertebrate Na+-coupled transporters of organic solutes.