SIGNAL TRANSDUCTION BY NEUROPEPTIDE RECEPTORS

我们研究的长期目标是了解信号的机制 神经肽受体的转导。K物质(神经激肽-A) 受体在正常和病理过程中都发挥着重要作用， 包括记忆保持和类风湿性关节炎[L，2，3]。的目标是 这里提出的研究是为了确定结构-功能关系 以神经激动素A受体为模型系统的神经肽受体 神经肽受体，它有七个跨越疏水的膜 地区。在配体结合后，神经肽受体与 G-蛋白来转导它们的信号。 结构-功能分析的一个关键突破是克隆 受体。我们已经克隆了人神经激肽A受体并将 在这一分析中使用。具体目标是1)确定功能 物质-K受体结构域参与G-蛋白相互作用 在神经激动素A受体和β2之间产生嵌合体- 利用不同G蛋白的肾上腺素能受体。优先级来自 肾上腺素能和毒碱能受体系统将指导选择 要交换的域。2)确定翻译后翻译的作用 神经激动素A受体的修饰。A)有潜力 神经激动素A受体上的肉豆蔻化和棕榈酰化位点。这个 这些位置的使用和重要性将通过代谢标签进行分析 实验和定点突变。B)对神经激动素A的反应 很快就不敏感了。在肾上腺素能系统中，脱敏作用 被证明是由C末端尾巴的磷酸化控制的。这个 神经激肽A受体C末端尾部的磷酸化作用 将通过体内32P标记和缺失突变进行分析 C末端的尾巴。 简明扼要地了解在相互作用中很重要的站点 神经肽受体及其转导蛋白(G蛋白)是 是理解信号转导机制所必需的 神经肽受体。G蛋白相互作用的部位及其作用 神经激肽A受体的翻译后修饰是 了解刺激或脱敏的机制 对神经激动素A的反应，在正常调节 正常的受体功能。对信号机制的认识 通过这些受体的转导可能会导致更有效的治疗药物 类风湿性关节炎等疾病和记忆保持的分析 诱导b型神经激肽A。

The long term goal of our research is to understand the mechanism of signal transduction by neuropeptide receptors. Substance-K (neurokinin-A) receptors play important roles in both normal and pathological processes, including memory retention and rheumatoid arthritis [l, 2, 3]. The goal of the research proposed here is to determine structure-function relationships of neuropeptide receptors using Neurokinin A receptor as a model system for neuropeptide receptors, which have seven hydrophobic membrane spanning regions. Following ligand binding, neuropeptide receptors couple with G-proteins to transduce their signals. A key breakthrough in analyzing structure-function is the cloning of the receptor. The human Neurokinin A receptor has been cloned by us and will be used in this analysis. Specific aims are 1) To determine functional domains of the substance-K receptor involved with G-protein interaction by producing chimeras between the neurokinin A receptor and the beta2- adrenergic receptor which utilize different G-proteins. Precedence from the adrenergic and muscarinic receptor systems will guide the choice of domains to be swapped. 2) To determine the role of post-translational modification of the Neurokinin A receptor. a) There are potential myristylation and palmitoylation sites on the Neurokinin A receptor. The use and importance of these sites will be analyzed by metabolic labelling experiments and site directed mutagenesis. b) The response to neurokinin A is rapidly desensitized. In the adrenergic system, desensitization has been shown to controlled by phosphorylation of the C-terminal tail. The role of phosphorylation of the C-terminal tail of the Neurokinin A receptor will be analyzed by in vivo labelling with 32p and by deletion mutagenesis of the C-terminal tail. A concise understanding of the sites important in the interaction between neuropeptide receptors and their transducing proteins (G-proteins) is necessary for understanding the mechanism of signal transduction by neuropeptide receptors. The site of G-protein interaction and the role of post-translational modifications of the Neurokinin A receptor are keys in understanding the mechanism of stimulation or desensitization of the response to Neurokinin A, important concepts in normal regulation of the proper receptor function. The understanding of mechanism of signal transduction by these receptors may lead to more potent drugs for treating diseases such as rheumatoid arthritis and for analysis of memory retention induced b Neurokinin A.