Cellular Pharmacology of Kappa Opiod Receptor

阿片受体（KOPR）是介导阿片受体的三种主要类型（<$，<$和<$）之一。 阿片类药物在体内的作用。KOPR的激活产生镇痛、烦躁不安、利尿、体温过低和 调节免疫反应。KOPR拮抗剂可能对抑制可卡因渴望有潜在的用处 以及抗抑郁和抗焦虑药物。KOPR是7 TMR家族的一员， 百日咳毒素敏感的G蛋白的各种效应。对于7 TMR。激动剂调节 下游信号传导分子依赖于细胞表面受体的可用性。的数量 细胞表面7 TMR反映了生物合成和内吞途径之间的平衡。所述后活化 内吞事件已被充分记录;然而，沿生物合成途径的调节沿着 更少被理解。本赠款申请的重点是描述KOPR贩运的监管特点 沿着生物合成途径，特别是通过蛋白质GEC 1，分拣蛋白和14-3-3蛋白，我们 被发现与KOPR有联系并参与KOPR的出口贩运。核心假设是， 出口运输由与KOPR相互作用的分子调节。具体目标如下。 (1)阐明GEC 1促进KOPR表达和运输的机制。的 假设GEC 1通过增强NSF的ATP酶活性而不是通过 将测试通过脂质缀合的膜结合。(2)调查14-3-3在贩卖人口中的作用 以及KOPR的细胞药理学。假设14-3-3蛋白与KOPR C-末端结合， 结构域和/或i3环，其掩蔽COPI结合，允许KOPR分选至质膜。(3)到 检查KOPR与分拣蛋白的相互作用及其功能后果。假设是 测试的是，分拣蛋白结合KOPR将受体分类到内体和溶酶体， 代表了一种新的ER后质量控制机制。我们还将研究KOPR的相互作用是否 影响信号传导和调节。拟议的研究将使人们更好地了解 细胞生物学的KOPR，并提供机制的见解调节输出的KOPR。此外，本发明还提供了一种方法， 这种理解对于其它膜结合受体具有重要意义， 输出的调节机制可能适用于某些其他蛋白质。

The ¿ opioid receptor (KOPR) is one of the three major types (¿, ¿ and ¿) of opioid receptors that mediate effects of opioids in vivo. Activation of KOPR produces analgesia, dysphoria, water diuresis, hypothermia and modulation of immune responses. KOPR antagonists may be potentially useful for curbing cocaine craving and as anti-depressants and anti-anxiety agents. KOPR, a member of the 7TMR family, is coupled through pertussis toxin-sensitive G proteins to a variety of effectors. For 7TMRs. the capacity of agonists to modulate downstream signaling molecules depends on the availability of the receptors on cell surface. The number of cell surface 7TMRs reflects a balance between biosynthesis and endocytosis pathways. The post-activation endocytic events have been well-documented; however, regulation along the biosynthesis pathway is much less understood. The focus of this grant application is to characterize the regulation of the KOPR trafficking along the biosynthesis pathway, in particular by the proteins GEC1, sortilin and 14-3-3 proteins, which we found to interact with the KOPR and to be involved in KOPR export trafficking. The central hypothesis is that the export trafficking is regulated by molecules interacting with the KOPR. The specific aims are as follows. (1) To delineate mechanisms underlying GEC1-promoted expression and trafficking of the KOPR. The hypothesis that GEC1 enhances KOPR expression by enhancing ATPase activity of NSF, but not by membrane association by lipid conjugation will be tested. (2) To investigate the role of 14-3-3 in the trafficking and cellular pharmacology of the KOPR. The hypothesis is that 14-3-3 proteins bind to KOPR C-terminal domain and/or i3 loop, which masks COPI binding, allowing the KOPR to sort to plasma membranes. (3) To examine the interaction of the KOPR with sortilin and its functional consequences. The hypothesis to be tested is that sortilin binding to the KOPR sorts the receptor to endosomes and lysosomes and this represents a novel post-ER quality control mechanism. We will also examine if the interactions of the KOPR with these proteins affect signaling and regulation. The proposed studies will provide better understanding of cell biology of the KOPR and provide mechanistic insights into regulation of export of the KOPR. In addition, such understanding will have important implications for other membrane bound receptors since these regulatory mechanisms of export are likely to be applicable to some other proteins.