Characterization of Glutamate Uptake into Synaptic Vesicles

抄録

<jats:title>Abstract:</jats:title><jats:p>Recent evidence indicates that L‐glutamate is taken up into synaptic vesicles in an ATP‐dependent manner, supporting the notion that synaptic vesicles may be involved in glutamate synaptic transmission. In this study, we further characterized the ATP‐dependent vesicular uptake of glutamate. Evidence is provided that 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, it is suggested that the vesicular uptake of glutamate is driven by electrochemical proton gradients generated by the Mg‐ATPase. Of particular interest is the finding that 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. It is proposed that this vesicular translocator plays a crucial role in determining the fate of glutamate as a neurotransmitter.</jats:p>

収録刊行物

被引用文献 (19)*注記

もっと見る

詳細情報 詳細情報について

問題の指摘

ページトップへ