CHARACTERIZATION OF GLUTAMATE UPTAKE INTO SYNAPTIC VESICLES
CHARACTERIZATION OF GLUTAMATE UPTAKE INTO SYNAPTIC VESICLES
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DOI：
10.1111/j.1471-4159.1985.tb07118.x
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发表时间：
1985-01-01
影响因子：
4.7
通讯作者：
UEDA, T
中科院分区：
文献类型：
--
作者：
NAITO, S;UEDA, T
l -谷氨酸以atp依赖的方式进入突触囊泡，提示突触囊泡可能参与谷氨酸突触传递。进一步表征了atp依赖性的谷氨酸囊泡摄取。mg -ATP酶，而不是ca -ATP酶，负责与谷氨酸摄取结合的ATP水解。atp依赖的谷氨酸摄取被已知的能驱散穿越染色质颗粒膜的电化学质子梯度的药物所抑制。因此，谷氨酸的囊泡摄取是由mg - atp酶产生的电化学质子梯度驱动的。在生理相关的毫摩尔浓度范围内，氯化物显著刺激atp依赖性谷氨酸摄取，提示神经内末端氯化物在突触囊泡中谷氨酸积累中的重要作用。囊泡谷氨酸转运体对l -谷氨酸具有高度特异性，不能与天冬氨酸及其相关药物和大多数谷氨酸类似物相互作用。显然，这种囊泡转运体在决定谷氨酸作为神经递质的命运方面起着至关重要的作用。
L-Glutamate is taken up into synaptic vesicles in an ATP-dependent manner, suggesting that synaptic vesicles may be involved in glutamate synaptic transmission. The ATP-dependent vesicular uptake of glutamate was further characterized. A Mg-ATPase, not Ca-ATPase, is responsible for the ATP hydrolysis coupled to the glutamate uptake. The ATP-dependent glutamate uptake was inhibited by agents known to dissipate the electrochemical proton gradient across the membrane of chromaffin granules. Hence, the vesicular uptake of glutamate is driven by electrochemical proton gradients generated by the Mg-ATPase. The ATP-dependent glutamate uptake is markedly stimulated by chloride over a physiologically relevant, millimolar concentration range, suggesting an important role of intranerve terminal chloride in the accumulation of glutamate in synaptic vesicles. The vesicular glutamate translocator is highly specific for L-glutamate, and failed to interact with aspartate, its related agents, and most of the glutamate analogs tested. Apparently, this vesicular translocator plays a crucial role in determining the fate of glutamate as a neurotransmitter.