PRIMATE TRACE AMINE RECEPTOR1 MODULATION BY THE DOPAMINE TRANSPORTER

这个子项目是利用由NIH/NCRR资助的中心拨款提供的资源的许多研究子项目之一。子项目和调查员(PI)可能从另一个NIH来源获得了主要资金，因此可能会出现在其他CRISE条目中。列出的机构是针对中心的，而不一定是针对调查员的机构。最近发现的示踪胺受体是药物滥用的潜在直接靶点，包括苯丙胺和3，4-亚甲基二氧基甲基苯丙胺(MDMA)。我们克隆了与人TA(1)有96%同源性的全长恒河猴痕量胺受体1(rhTA(1))。结果：通过cAMP反应元件-荧光素酶检测，微量胺酪胺和β-苯乙胺(PEA)以及单胺转运体底物(+/-)-苯丙胺和(+/-)-MDMA可刺激表达rhTA(1)的细胞内cAMP的积累。可卡因不能刺激rh TA(1)细胞内cAMP的积累，但可阻断多巴胺转运体介导的[(3)H]PEA转运。与人多巴胺转运体共转染可增强PEA、安非他明和MDMA介导的重组人TA(1)受体激活。由于TA(1)(EGFP-rhTA(1)嵌合体)主要在细胞内，可以想见，多巴胺转运体可以促进特定激动剂对细胞内TA(1)的访问。在恒河猴黑质中检测到重组人TA(1)基因的表达，提示TA(1)可能与多巴胺转运体共存于多巴胺神经元中。讨论：灵长类TA(1)受体是痕量胺、苯丙胺和MDMA的直接靶标。这些受体也可以通过修饰单胺转运体功能而成为苯丙胺、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膜或突触后膜上。干扰单胺转运体的载体功能，从而导致细胞外痕量胺水平的上升，可以激活这些受体。

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.