Electrophysiological characterization of AtAMT1;4, an extraordinarily high affinity ammonium transporter from Arabidopsis thaliana
Electrophysiological characterization of AtAMT1;4, an extraordinarily high affinity ammonium transporter from Arabidopsis thaliana
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DOI：
10.1101/820712
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发表时间：
2019-10
期刊：
影响因子：
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通讯作者：
Nino Bindel;B. Neuhäuser
中科院分区：
文献类型：
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作者：
Nino Bindel;B. Neuhäuser
在植物中，高亲和力转运蛋白介导铵离子跨膜转运。在拟南芥（Arabidopsis thaliana）中，这些铵转运蛋白（AMTs）中的六个在基因组上编码。所有这些都显示出独特的表达模式。虽然大多数AMT在根中高度表达，但AtAMT 1;4表达仅限于花粉粒和花粉管。在这里，我们解决了AtAMT 1;4在异源非洲爪蟾卵母细胞系统中的运输特性。双电极电压钳测量标记AtAMT 1;4作为产电高亲和力铵转运蛋白。转运是饱和的，对铵离子表现出极高的亲和力，Km值低于10 µM。
In plants high affinity transport proteins mediate the essential transport of ammonium across membranes. In Arabidopsis thaliana six of these AMmonium Transporters (AMTs) are encoded on the genome. All of these show a unique expression pattern. While most AMTs are highly expressed in the root, AtAMT1;4 expression is limited to the pollen grains and the pollen tube. Here, we addressed the transport characteristics of AtAMT1;4 in the heterologous Xenopus laevis oocytes system. Two electrode voltage clamp measurements tagged AtAMT1;4 as an electrogenic high affinity ammonium transporter. The transport was saturable and showed extraordinarily high affinity for ammonium with a Km value lower than 10 µM.