机构：[1]Department of Blood Transfusion, The Fifth Affiliated Hospital, Southern Medical University, Guangzhou, Guangdong 510900, China.[2]Department of Immunology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong 510515, China.[3]Department of Genetic Metabolism, Children’s Hospital, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, Guangxi 530003, China.[4]Department of Neurology, Foshan Hospital of Traditional Chinese Medicine, Guangzhou University of Chinese Medicine, Foshan, Guangdong 528000, China.深圳市中医院深圳医学信息中心[5]Teaching Center of Experimental Medicine, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong 510515, China.[6]Department of Thoracic Cardiovascular Surgical, The Fifth Affiliated Hospital, Southern Medical University, Guangzhou, Guangdong 510900, China.
Excitatory amino acid transporter 2 (EAAT2), also known as glial glutamate transporter type 1 (GLT-1), plays an important role in maintaining the extracellular glutamate concentrations below neurotoxic levels. The highly conserved TM2 transmembrane domain of GLT-1 maintains a stable position during the transport cycle; however, the effect of the transport cycle on the topology of TM4 in not well established. To further reveal the function of TM4, two cysteine pairs between TM2 and TM4 were introduced using site-directed mutagenesis. A significant decrease of transport activity was observed in the I93C/V241C and I97C/V241C mutants upon application of the oxidative cross-linking reagent, copper (II) (1,10-phenanthroline)3 (CuPh), which suggests that a conformational shift is essential for transporter activity. Furthermore, the decrease in activity by CuPh crosslinking was enhanced in external media with glutamate or potassium, which suggests that TM2 and TM4 assume closer proximity in the inward-facing conformation of the transporter. Our results suggest that the TM4 domain of GLT-1, and potentially other glutamate transporters, undergoes a complex conformational shift during substrate translocation, which involves an increase in the proximity of the TM2 and TM4 domains in the inward-facing conformation.
基金：
This work was supported by grants from the National Natural Science Foundation of China (Grant 31170734,
31570716), the Science and Technology Planning Project of Guangdong Province (2012B050200003,
2013B021800305, 2016A050502025), the Science and Technology Planning Project of Guangzhou
(2013J4500018, 2014J4100008), the Scientific and Technological Innovation Programs of Higher Education
Institution in Guangdong (2013KJCX0041) and the International Centre for Genetic Engineering and
Biotechnology (Grant CRP/CHN11-01).
语种：
外文
PubmedID：
中科院(CAS)分区：
出版当年[2015]版：
大类|2 区综合性期刊
小类|2 区综合性期刊
最新[2025]版：
大类|3 区综合性期刊
小类|3 区综合性期刊
第一作者：
第一作者机构：[1]Department of Blood Transfusion, The Fifth Affiliated Hospital, Southern Medical University, Guangzhou, Guangdong 510900, China.[2]Department of Immunology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong 510515, China.[3]Department of Genetic Metabolism, Children’s Hospital, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, Guangxi 530003, China.
共同第一作者：
通讯作者：
通讯机构：[1]Department of Blood Transfusion, The Fifth Affiliated Hospital, Southern Medical University, Guangzhou, Guangdong 510900, China.[2]Department of Immunology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong 510515, China.
推荐引用方式(GB/T 7714)：
Xiuliang Rong,Feng Tan,Xiaojuan Wu,et al.TM4 of the glutamate transporter GLT-1 experiences substrate-induced motion during the transport cycle.[J].Scientific reports.2016,6:34522.doi:10.1038/srep34522.
APA：
Xiuliang Rong,Feng Tan,Xiaojuan Wu,Xiuping Zhang,Lingli Lu...&Shaogang Qu.(2016).TM4 of the glutamate transporter GLT-1 experiences substrate-induced motion during the transport cycle..Scientific reports,6,
MLA：
Xiuliang Rong,et al."TM4 of the glutamate transporter GLT-1 experiences substrate-induced motion during the transport cycle.".Scientific reports 6.(2016):34522
