Fast removal of synaptic glutamate by postsynaptic transporters
Fast removal of synaptic glutamate by postsynaptic transporters
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DOI：
10.1016/s0896-6273(00)00132-x
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发表时间：
2000-11-01
期刊：
影响因子：
16.2
通讯作者：
Attwell, D
中科院分区：
文献类型：
--
作者：
Auger, C;Attwell, D
谷氨酸转运蛋白被认为只能缓慢地从突触间隙中清除谷氨酸，因为它们循环缓慢。然而，我们发现，当谷氨酸结合到小脑攀爬纤维突触的突触后转运蛋白时，它会引起构象变化和内向电流，反映谷氨酸在几毫秒内从突触间隙中清除，时间尺度比整个周期时间快得多。与目前的模型相反，谷氨酸去除不需要结合的细胞外质子，和转运阴离子电导激活的时间过程不同于谷氨酸去除。与谷氨酸去除相关的电荷运动与突触释放的谷氨酸被突触后转运蛋白从突触间隙中去除的大部分是一致的。
Glutamate transporters are believed to remove glutamate from the synaptic cleft only slowly because they cycle slowly. However, we show that when glutamate binds to postsynaptic transporters at the cerebellar climbing fiber synapse, it evokes a conformation change and inward current that reflect glutamate removal from the synaptic cleft within a few milliseconds, a time scale much faster than the overall cycle time. Contrary to present models, glutamate removal does not require binding of an extracellular proton, and the time course of transporter anion conductance activation differs from that of glutamate removal. The charge movement associated with glutamate removal is consistent with the majority of synaptically released glutamate being removed from the synaptic cleft by postsynaptic transporters.