A single vesicular glutamate transporter is sufficient to fill a synaptic vesicle
A single vesicular glutamate transporter is sufficient to fill a synaptic vesicle
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DOI：
10.1016/j.neuron.2005.11.032
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发表时间：
2006-01-05
期刊：
影响因子：
16.2
通讯作者：
DiAntonio, A
中科院分区：
文献类型：
--
作者：
Daniels, RW;Collins, CA;DiAntonio, A
量子大小是突触后对单个突触囊泡释放的反应，部分取决于囊泡内递质的量。在谷氨酸能突触中，囊泡谷氨酸转运体（VGLUT）使囊泡充满谷氨酸。虽然升高的VGLUT表达增加量子尺寸，但填充囊泡所需的转运蛋白的最小数量是未知的。在果蝇DVGLUT突变体中，降低的转运蛋白水平导致自发量子释放频率的剂量依赖性降低，而量子大小没有变化。量子频率不受囊泡数量或受损胞吐作用的限制。这表明转运蛋白的单个功能单元对于填充囊泡至完成是必要且足够的，并且没有DVGLUT的囊泡是空的。与空囊泡的存在一致，在dvglut突变突触中，突触囊泡较小，这表明囊泡填充和/或转运蛋白水平是囊泡大小的重要决定因素。
Quantal size is the postsynaptic response to the release of a single synaptic vesicle and is determined in part by the amount of transmitter within that vesicle. At glutamatergic synapses, the vesicular glutamate transporter (VGLUT) fills vesicles with glutamate. While elevated VGLUT expression increases quantal size, the minimum number of transporters required to fill a vesicle is unknown. In Drosophila DVGLUT mutants, reduced transporter levels lead to a dose-dependent reduction in the frequency of spontaneous quantal release with no change in quantal size. Quantal frequency is not limited by vesicle number or impaired exocytosis. This suggests that a single functional unit of transporter is both necessary and sufficient to fill a vesicle to completion and that vesicles without DVGLUT are empty. Consistent with the presence of empty vesicles, at dvglut mutant synapses synaptic vesicles are smaller, suggesting that vesicle filling and/or transporter level is an important determinant of vesicle size.