Amino acid transport System A resembles System N in sequence but differs in mechanism
Amino acid transport System A resembles System N in sequence but differs in mechanism
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DOI：
10.1073/pnas.140152797
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发表时间：
2000-07-05
影响因子：
11.1
通讯作者：
Edwards, RH
中科院分区：
文献类型：
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作者：
Reimer, RJ;Chaudhry, FA;Edwards, RH
经典氨基酸转运系统A占哺乳动物细胞摄取Na+依赖性中性氨基酸的大部分。系统A还提供了一个通过生理刺激进行短期和长期调节的范例。我们现在报告的分离的cDNA编码系统A，显示出密切的相似性，最近确定的系统N转运蛋白（SN1）。系统A转运蛋白（SA 1）和SN 1具有许多共同的功能特征，包括对低pH的显著敏感性，但与SN 1不同，SA 1不介导质子交换。由SA1介导的转运也是产电的。因此，氨基酸转运系统A和N在功能和结构上似乎密切相关，但在离子偶联方面表现出重要的差异。
Classical amino acid transport System A accounts for most of the Na+-dependent neutral amino acid uptake by mammalian cells. System A has also provided a paradigm for short- and long-term regulation by physiological stimuli. We now report the isolation of a cDNA encoding System A that shows close similarity to the recently identified System N transporter (SN1). The System A transporter (SA1) and SN1 share many functional characteristics, including a marked sensitivity to low pH, but, unlike SN1, SA1 does not mediate proton exchange. Transport mediated by SA1 is also electrogenic. Amino acid transport Systems A and N thus appear closely related in function as well as structure, but exhibit important differences in ionic coupling.