STRUCTURE/FUNCTION ANALYSIS OF OPIOID RECEPTOR SUBTYPES

毒瘾是一种慢性复发性脑部疾病 表现为各种行为对双方都有害 个人和社会。对精神分裂症的神经生物学的理解 上瘾需要了解大脑的运作方式。 阿片类药物是如何改变大脑功能的 上瘾的过程。阿片类药物通过参与 脑细胞表面的阿片受体。分子 阿片类药物三种主要亚型基因的克隆 受体Mu、Delta和kappa为研究开辟了新的途径。 阿片受体激活和信号转导通路。 尽管关于受体一般性质的预测 根据阿片类药物的结构建立了结合部位 生物碱和多肽，特定结构域和氨基的作用 最近对受体功能的酸残基进行了研究。 体外诱变方法学与联合应用 受体嵌合体的分析。这项提案旨在确定 构成表面的关键结构决定因素 结合Mu和Delta受体的配基结合缝隙，并鉴定 负责这些化合物的配体选择性的残基 受体亚型。我们确定他的223亩 受体是配体识别的关键，也是配体识别的可能部位。 NEM烷基化反应将进一步研究。假设 泛素化参与配体依赖的内吞作用 测试过。此外，受体内的氨基酸是 负责激活G蛋白和受体介导的 将以内吞作用为特征。这项研究将有直接的 对长期目标在分子水平上的理解的影响 阿片受体如何与其配体相互作用并激活 导致细胞反应的信号转导途径。它是 预计分子和细胞研究的影响， 本申请中提出的阿片类药物和多肽将有助于 对耐受性的机制的阐明 对阿片类药物的身体依赖。

Drug addiction is a chronic relapsing disease of the brain manifested by a variety of behaviors that are detrimental to both the individual and society. An understanding of the neurobiology of addiction will require knowledge about how the brain functions normally and how opioid drugs alter brain functioning over the course of addiction. Opioid drugs initiate their effects by engaging opioid receptors on the cell surface of brain cells. The molecular cloning of cDNAs from the three major subtypes of opioid receptors, mu, delta and kappa, has opened new avenues to study opioid receptor activation and signal transduction pathways. Although predictions about the general nature of the receptor binding site have been made based on the structures of opioid alkaloids and peptides, the role of particular domains and amino acid residues for proper receptor function has been recently studies using the methodology of in vitro mutagenesis in conjunction with analysis of receptor chimeras. This proposal seeks to identify the critical structural determinants that comprise the surface of the ligand binding crevice for the mu and delta receptor, and to identify the residues that are responsible for the ligand selectivity of these receptor subtypes. Our determination that His223 of the mu receptor is critical for ligand recognition and is a possible site for NEM alkylation will be further investigated. The hypothesis that ubiquitination is involved in ligand-dependent endocytosis will be tested. In addition, amino acids within the receptor that are responsible for activation of G proteins and receptor-mediated endocytosis will be characterized. This research will have a direct impact on the long-term objective to understand at the molecular level how opioid receptors interact with their ligands and activate signal transduction pathways that result in cellular responses. It is anticipated that the molecular and cellular studies of the effects of opioid drugs and peptides proposed in this application will aid in the elucidation of the mechanisms involved in tolerance to, and physical dependence on, opioids.