PRIMATE TRACE AMINE RECEPTOR1 MODULATION BY THE DOPAMINE TRANSPORTER

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。最近发现的微量胺受体是滥用药物的潜在直接靶点，包括安非他明和3,4-亚甲基二氧甲基苯丙胺（MDMA）。我们克隆了全长恒河猴微量胺受体1 (rhTA(1))，其与人类微量胺受体(1)同源性达96%。结果：通过cAMP反应元件-荧光素酶测定，微量胺（酪胺和-苯乙胺（PEA））和单胺转运体底物(+/-)-安非他明和(+/-)- mdma刺激了表达rhTA(1)的细胞系中cAMP的积累。可卡因不刺激cAMP在rhTA(1)细胞中的积累，但阻断了多巴胺转运体介导的[(3)H]PEA转运。人多巴胺转运体共转染增强了PEA-、安非他明-和mdma介导的rhTA(1)受体激活。因为TA(1) （EGFP-rhTA(1)嵌合体）主要在细胞内，可以想象多巴胺转运体可以促进特异性激动剂进入细胞内TA(1)。在恒河猴黑质中检测到rhTA(1) mRNA的表达，提示TA(1)可能与多巴胺神经元中的多巴胺转运体共定位。讨论：灵长类TA(1)受体是微量胺、安非他明和MDMA的直接靶点。这些受体也可能通过修饰单胺转运体功能成为安非他明、MDMA和可卡因的间接靶点。可以想象，rhTA(1)受体可能位于突触前或突触后膜上。干扰单胺转运体的载体功能，导致细胞外微量胺水平升高，可激活这些受体。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Recently identified trace amine receptors are potential direct targets for drugs of abuse, including amphetamine and 3,4-methylenedioxymethamphetamine (MDMA). We cloned full-length rhesus monkey trace amine receptor 1 (rhTA(1)) that was 96% homologous to human TA(1). Results: The trace amines tyramine and beta-phenylethylamine (PEA) and the monoamine transporter substrates (+/-)-amphetamine and (+/-)-MDMA stimulated cAMP accumulation in rhTA(1)-expressing cell lines, as measured by a cAMP response element-luciferase assay. Cocaine did not stimulate cAMP accumulation in rhTA(1) cells, but it blocked [(3)H]PEA transport mediated by the dopamine transporter. Cotransfection with the human dopamine transporter enhanced PEA-, amphetamine-, and MDMA-mediated rhTA(1) receptor activation. Because TA(1) (EGFP-rhTA(1) chimera) was largely intracellular, conceivably the dopamine transporter can facilitate access of specific agonists to intracellular TA(1). rhTA(1) mRNA expression was detected in rhesus monkey substantia nigra, implying that TA(1) may be colocalized with the dopamine transporter in dopamine neurons. Discussion: Primate TA(1) receptors are direct targets of trace amines, amphetamine, and MDMA. These receptors could also be indirect targets of amphetamine, MDMA, and cocaine through modification of monoamine transporter function. Conceivably, rhTA(1) receptors may be located on pre- or postsynaptic membranes. Interference with the carrier function of monoamine transporters with a consequent rise of extracellular levels of trace amines could activate these receptors.