Molecular analysis of system N suggests novel physiological roles in nitrogen metabolism and synaptic transmission
Molecular analysis of system N suggests novel physiological roles in nitrogen metabolism and synaptic transmission
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DOI：
10.1016/s0092-8674(00)81674-8
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发表时间：
1999-12-23
期刊：
影响因子：
64.5
通讯作者：
Edwards, RH
中科院分区：
文献类型：
--
作者：
Chaudhry, FA;Reimer, RJ;Edwards, RH
氨基酸谷氨酰胺在氮代谢中具有中心作用。虽然负责其跨细胞膜转运的分子机制仍然知之甚少，经典的氨基酸转运系统N显得特别重要。利用细胞内pH值的测量，我们现在已经确定了一个孤儿蛋白相关的囊泡神经递质转运系统N。功能分析表明，这种蛋白质（SN1）涉及H+交换以及Na+共转运，在生理条件下，介导谷氨酰胺流出以及摄取。连同SN1的表达模式，这些不寻常的属性表明新的生理作用系统N在氮代谢和突触传递。
The amino acid glutamine has a central role in nitrogen metabolism. Although the molecular mechanisms responsible for its transport across cell membranes remain poorly understood, classical amino acid transport system N appears particularly important. Using intracellular pH measurements, we have now identified an orphan protein related to a vesicular neurotransmitter transporter as system N. Functional analysis shows that this protein (SN1) involves H+ exchange as well as Na+ cotransport and, under physiological conditions, mediates glutamine efflux as well as uptake. Together with the pattern of SN1 expression, these unusual properties suggest novel physiological roles for system N in nitrogen metabolism and synaptic transmission.