MUTATIONS OF MUSCARINIC CHOLINERGIC RECEPTOR GENES

描述：这个项目解决了潜在的分子机制 M胆碱能受体的信号转导和调节。 在之前的项目期间，m1、m2和m3受体是 被定点突变修饰以定义与第二个相关的结构域 信使信令、内部化和下调调控。 本提案侧重于毒鼠强的直接相互作用。 具有参与受体功能的蛋白质的受体。其中包括a) 偶联到特定的G蛋白，b)膜与离子的相互作用 C)蛋白激酶的磷酸化，以及d)相互之间的聚集 受体本身以及与其他膜蛋白的结合。 完整膜蛋白的聚集在热力学上是有利的，并且 G蛋白偶联受体和离子通道倾向于形成同源低聚物 (如关于M2受体的报道)或杂寡体。异质聚集体 尚未对G蛋白偶联受体进行充分的研究；然而， 聚集体可能在所有受体功能中发挥重要作用。 将开发研究受体聚集的方法，使用 生物物理、生化、生物化学和遗传学方法，以了解 膜蛋白四级结构水平上的受体功能 组织。这项研究还应解决这样一个问题，即 M受体可呈现多种构象，每一种信号 沿着不同的小路。中概述的研究的预期见解 这一建议将有助于设计胆碱能疗法。 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.