Allosteric modulation of dopamine transport-Functional and Biochemical Studies

修改项目摘要/摘要部分 质膜单胺转运体（MAT）包括血清素（SERT）、去甲肾上腺素（NET）和多巴胺（DAT）转运体，其通过各自神经递质的再摄取在限制单胺介导的神经传递中起关键作用。转运蛋白是临床上使用的精神兴奋剂和抗抑郁药的主要靶点。持续需要治疗药物来治疗涉及异常单胺信号传导的脑疾病，这为我们进一步理解转运蛋白功能和确定靶向它们的新方法提供了一个令人信服的理由。在这个项目中，我们将追求新的想法，即化合物，特别是从事一个新的变构网站，我们已经确定在DAT将提供有用的机制信息变构转运蛋白的调制。更重要的是，我们相信这些化合物可能具有治疗潜力。 我们小组以前的实验在化学文库的虚拟筛选中靶向了SERT中的等效变构位点，这些化学文库鉴定了与该位点相互作用并显示出显著的转运蛋白调节活性的分子。这些化合物已经揭示，参与该位点以全新的方式调节MAT活性，包括刺激转运蛋白功能和影响与转运蛋白配体如选择性5-羟色胺再摄取抑制剂（SSRI）和精神兴奋剂的相互作用。在DAT的相应实验中，我们现在已经确定了化合物，其中包括KM 822，它可以改变DAT功能及其与外源配体的相互作用，并改变精神兴奋剂引起的行为。 该项目的总体假设是，DAT中变构位点的特异性参与将提供有关多巴胺转运过程机制的有价值的信息，并可为开发基于DAT的药物提供新的治疗途径。我们建议通过进一步开发我们的工具化合物来研究不同类型的变构调制，采用计算，功能和生化测定来表征化合物如何调节转运机制。因此，该项目的成功完成将导致DAT的新型配体的开发，这些配体可以用作实验工具，以进一步我们对这种重要的神经递质转运蛋白的理解，重要的是，它可以开辟新的治疗途径。

Modified Project Summary/Abstract Section The plasma-membrane monoamine transporters (MATs), including the serotonin (SERT), norepinephrine (NET) and dopamine (DAT) transporters, serve a pivotal role in limiting monoamine-mediated neurotransmission through the reuptake of their respective neurotransmitters. The transporters are the main target of clinically used psychostimulants and antidepressants. The continuing need for therapeutic drugs to treat brain disorders involving aberrant monoamine signaling provides a compelling reason to further our understanding of transporter function and to identify novel ways of targeting them. In this project we will pursue the novel idea that compounds that specifically engage a novel allosteric site we have identified in DAT will provide useful mechanistic information regarding allosteric transporter modulation. Of further significance we believe these compounds could have therapeutic potential. Previous experiments in our group targeted the equivalent allosteric site in SERT in a virtual screening of chemical libraries that identified molecules that interact with this site and display remarkable transporter-modulating activities. These compounds have revealed that engaging this site modulate MAT activity in entirely novel ways, including stimulating transporter function and affecting the interaction with transporter ligands such as the selective serotonin reuptake inhibitors (SSRIs) and psychostimulants. In corresponding experiments on DAT, we have now identified compounds, KM822 among others, that modifies DAT function and its interaction with exogenous ligands and modifies psychostimulant-elicited behaviors. The overarching hypothesis of this project is that the specific engagement of the allosteric site in DAT will provide valuable information regarding mechanisms of the dopamine transport process and could provide novel therapeutic avenues for developing DAT-based medications. We propose to pursue this idea by further developing our tool compounds to study different types of allosteric modulation employing computational, functional, and biochemical assays to characterize how the compounds modulate transport mechanisms. Consequently, the successful completion of this project will result in the development of novel ligands of DAT that can be employed as experimental tools to further our understanding of this important neurotransmitter transporter and importantly, it could open new therapeutic avenues.