Molecular cloning and functional characterization of a GABA transporter from the CNS of the cabbage looper, Trichoplusia ni
Molecular cloning and functional characterization of a GABA transporter from the CNS of the cabbage looper, Trichoplusia ni
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DOI：
10.1016/s0965-1748(99)00039-9
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发表时间：
1999-07-01
影响因子：
3.8
通讯作者：
Donly, C
中科院分区：
文献类型：
--
作者：
Gao, XJ;McLean, H;Donly, C
在粉纹夜蛾（Trichoplusia ni）中克隆了编码GABA转运蛋白的cDNA，并在杆状病毒感染的昆虫细胞中表达。该cDNA含有编码608个残基的蛋白质的ORF，命名为TmGAT。推导的氨基酸序列的亲水性分析表明12个跨膜结构域，类似于所有其他克隆的Na+/Cl-依赖性GABA转运蛋白的结构。推导的氨基酸序列与烟草天蛾胚胎中表达的GABA转运蛋白（MasGAT）具有高度的同源性。TmGAT mRNA仅在脑中表达。与对照感染的细胞相比，重组杆状病毒感染的Sf 21细胞表现出20- 30倍的[H-3]GABA摄取增加。使用几种GABA摄取阻断剂来确定TmGAT的药理学特征。尽管TmGAT在动力学性质、离子依赖性的化学计量和药理学性质方面与哺乳动物神经元GABA转运蛋白GAT-1最相似，但TmGAT与哺乳动物GAT-1的区别在于环状GABA类似物（如哌啶甲酸及其衍生物）不能抑制昆虫蛋白对GABA的摄取。TmGAT的独特药理学表明，鳞翅目CNS中的GABA转运系统可能是未来开发用于控制农业重要昆虫的速效神经活性剂的有用靶标。版权所有（C）1999由爱思唯尔科学有限公司出版。保留所有权利。
A cDNA encoding a GABA transporter in the caterpillar Trichoplusia ni has been cloned and expressed in baculovirus-infected insect cells. The cDNA contains an ORF encoding a 608-residue protein, designated TmGAT. Hydropathy analysis of the deduced amino acid sequence suggests 12 transmembrane domains, a structure similar to that of all other cloned Na+/Cl--dependent GABA transporters. The deduced amino acid sequence shows high identity with a GABA transporter (MasGAT) expressed in the embryo of Manduca sexta. Expression of TmGAT mRNA was detected only in the brain. Sf21 cells infected with recombinant baculovirus exhibited a 20- to 30-fold increase in [H-3]GABA uptake compared to control-infected cells. Several blockers of GABA uptake were used to determine the pharmacological profile of TmGAT. Although most similar to mammalian neuronal GABA transporter GAT-1 in its kinetic properties, stoichiometry of ionic dependence and pharmacological properties, TmGAT may be distinguished from mammalian GAT-1 by the inability of cyclic GABA analogues, such as nipecotic acid and its derivatives, to inhibit GABA uptake by the insect protein. The unique pharmacology of TmGAT suggests that the GABA transport system in the lepidopteran CNS could be a useful target in the future development of rapidly-acting neuroactive agents used to control agriculturally-important insects. Crown copyright (C) 1999 Published by Elsevier Science Ltd. All rights reserved.