Torres Gonzalo E, Amara Susan G
Department of Neurobiology, University of Pittsburgh School of Medicine, 3501 Fifth Avenue, Pittsburgh, PA 15261, USA.
Curr Opin Neurobiol. 2007 Jun;17(3):304-12. doi: 10.1016/j.conb.2007.05.002. Epub 2007 May 16.
Neurotransmitters are rapidly removed from the extracellular space primarily through the actions of plasma membrane transporters. This uptake process is not only essential in the termination of neurotransmission but also serves to replenish intracellular levels of transmitter for further release. Neurotransmitter transporters couple the inward movement of substrate to the movement of Na(+) down a concentration gradient and, in addition to their transport function, some carriers also display channel-like activities. Five Na(+)/K(+)-dependent glutamate transporter subtypes belong to the solute carrier 1 (SLC1) family and a second family, SLC6, encompasses the Na(+)/Cl(-)-dependent transporters for dopamine, 5-hydroxytryptamine (serotonin), noradrenaline, GABA and glycine. Recent advances, including high-resolution structures from both families, are now providing new insights into the molecular determinants that contribute to substrate translocation and ion channel activities. Other influential studies have explored how cellular regulatory mechanisms modulate transporter function, and how the different functions of the carrier shape the patterns of neurotransmitter signaling. This review focuses on recent studies of glutamate and monoamine transporters as prototypes of the two carrier families.
神经递质主要通过质膜转运体的作用迅速从细胞外空间清除。这种摄取过程不仅在神经传递的终止中至关重要，而且还用于补充细胞内递质水平以进行进一步释放。神经递质转运体将底物的内向运动与Na(+) 沿浓度梯度的运动偶联，并且除了其转运功能外，一些载体还表现出类似通道的活性。五种Na(+)/K(+) 依赖性谷氨酸转运体亚型属于溶质载体1 (SLC1) 家族，第二个家族SLC6包括用于多巴胺、5-羟色胺（血清素）、去甲肾上腺素、GABA和甘氨酸的Na(+)/Cl(-) 依赖性转运体。最近的进展，包括来自这两个家族的高分辨率结构，现在为有助于底物转运和离子通道活性的分子决定因素提供了新的见解。其他有影响力的研究探讨了细胞调节机制如何调节转运体功能，以及载体的不同功能如何塑造神经递质信号传导模式。本综述重点关注作为两个载体家族原型的谷氨酸和单胺转运体的最新研究。
