MUTATIONS OF MUSCARINIC CHOLINERGIC RECEPTOR GENES

描述：该项目涉及的分子机制， 毒蕈碱胆碱能受体信号转导和调节。 在上一个项目期间，m1、m2和m3受体被 通过定点诱变修饰以限定与第二个相关的结构域 信使信号传导、内化和下调。 目前的建议集中在毒蕈碱的直接相互作用， 受体与参与受体功能的蛋白质。 其中包括a） 与特异性G蛋白偶联，B）与离子的膜界定的相互作用 通道，c）通过蛋白激酶的磷酸化，和d）聚集在 受体本身和其他膜蛋白。 整合膜蛋白的聚集是有利的， G蛋白偶联受体和离子通道倾向于形成同源寡聚体 (as报道为M2受体）或异源寡聚体。 异质聚集 尚未对G蛋白偶联受体进行充分研究;然而， 聚集体可能在所有受体功能中起重要作用。 将开发研究受体聚集的方法， 生物物理、生物化学和遗传学方法， 膜蛋白四级结构水平上的受体功能 organization. 本研究报告还应探讨以下问题： 毒蕈碱受体可以呈现多种构象，每种都发出信号 沿着不同的路径。 中概述的研究的预期见解 这一建议应有助于设计胆碱能治疗， 认知障碍

DESCRIPTION: This project addresses the molecular mechanisms underlying signal transduction and regulation of muscarinic cholinergic receptors. During the previous project period, the m1, m2, and m3 receptors were modified by site-directed mutagenesis to define domains relevant to second messenger signaling, internalization, and downregulation. The present proposal focuses on the direct interactions of the muscarinic receptors with proteins involved in receptor functions. These include a) coupling to specific G proteins, b) membrane-delimited interactions with ion channels, c) phosphorylation by protein kinases, and d) aggregation among the receptors themselves and with other membrane proteins. Aggregation of integral membrane proteins is thermodynamically favored, and G protein coupled receptors and ion channels tends to form homo-oligomers (as reported for the m2 receptor) or hetero-oligomers. Hetero-aggregation has not been adequately investigated for G protein-coupled receptors; yet, aggregates may play essential roles in all receptor functions. Methodologies will be developed to study receptor aggregation, using biophysical, biochemical, aand genetic approaches in order to understand receptor function at the quaternary structural level of membrane protein organization. This study should also address the question as to whether muscarinic receptors can assume multiple conformations, each signalling along distinct pathways. The expected insights from the studies outlined in this proposal should assist in the design of cholinergic therapy for cognitive disorders.