Cellular Pharmacology of Kappa Opiod Receptor

阿片受体(KOPR)是阿片受体的三种主要类型之一。 阿片类药物在体内的作用。激活KOPR可产生止痛、烦躁不安、利水、体温过低和 调节免疫反应。KOPR拮抗剂可能对抑制可卡因的渴望有潜在的帮助 作为抗抑郁剂和抗焦虑剂。KOPR是7TMR家族的成员，通过 百日咳毒素敏感的G蛋白对多种效应物。适用于7TMR。激动剂的调节能力 下游信号分子依赖于细胞表面受体的可用性。数量 细胞表面7TMRs反映了生物合成和内吞作用途径之间的平衡。激活后 内吞事件已经被很好地记录下来；然而，沿着生物合成途径的调节有很多 更少人理解。这项赠款申请的重点是描述对KOPR贩运的管制 沿着生物合成途径，特别是通过蛋白质GEC1，山梨素和14-3-3蛋白质，我们 被发现与KOPR互动，并参与KOPR出口贩运。中心假设是 出口贩运受到与KOPR相互作用的分子的调控。具体目标如下。 (1)描述GEC1促进的KOPR表达和贩运的潜在机制。这个 假设GEC1通过增强NSF的ATPase活性而不是通过 将测试通过脂质结合而形成的膜结合。(2)调查14-3-3在人口贩运中的作用 和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，它屏蔽COPI结合，允许KOPR分选到质膜。(3)至 研究KOPR与山梨素的相互作用及其功能后果。假设是 测试表明，与KOPR结合的山梨素将受体分类为内切体和溶酶体，这 代表了一种新的ER后质量控制机制。我们还将研究KOPR的互动是否 与这些蛋白质一起影响信号和调节。拟议的研究将使人们更好地了解 KOPR的细胞生物学，并提供对KOPR出口监管的机械性见解。此外, 这种理解将对其他膜结合受体具有重要意义，因为这些 出口的调节机制可能也适用于其他一些蛋白质。

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.