Vesicular Glutamate Transporter as Metabolic Regulator.

水疱性谷氨酸转运蛋白（VGLUT）和水疱性抑制性氨基酸转运蛋白（VIAAT）分别在谷氨酸和gaba介导的化学传递中起重要作用。利用生物化学、细胞生物学和分子生物学等方法，对这些转运体的结构、功能和生理意义进行了研究。研究结果总结如下：(1)揭示了VGLUT2的拓扑结构。(2)利用纯化后的VGLUT和脂质体建立了VGLUT的体外检测体系，发现了一些用于运输和靶向的必需氨基酸残基。(3)用纯化的VIAAT鉴定必需氨基酸残基。实际上，通过aat运输-丙氨酸。(4)以VGLUT1 KO小鼠为实验对象，研究谷氨酸信号在外周组织中的生理意义。我们发现破骨细胞通过胞吞作用分泌谷氨酸，其缺陷导致骨质疏松。(5)我们发现了VGLUT的强可逆抑制剂。(6)我们发现了负责ATP囊状储存的囊状核苷酸转运蛋白（VNUT）。这种转运体似乎在嘌呤能神经传递中起着核心作用。

Vesicular glutamate transporter (VGLUT) and vesicular inhibitory amino acid transporter (VIAAT) are essential in glutamate- and GABA-mediated chemical transmission, respectively. Using biochemical, cellular biological and molecular biological approaches, we have elucidated structure, function and physiological significance of these transporters. The summaries of the results obtained in the studies are as follows:(1) We revealed topology of VGLUT2.(2) We established in vitro assay system for VGLUT using purified VGLUT and liposome, and revealed some essential amino acid residures for the transport and targeting.(3) We identified essential amino acid residues with purified VIAAT.Actually speaking VIAAT transports beta-alanine.(4) We studied physiological significance of the glutamate signaling in the peripheral tissues using VGLUT1 KO mice. We found that osteoclasts secrete glutamate through transcytosis, and its defect caused osteoporosis.(5) We found strong reversible inhibitors for VGLUT.(6)We identified vesicular nucleotide transporter (VNUT) that is responsible for vesicular storage of ATP. This transporter seems to play a central role in purinergic neurotransmission.