Post-transcriptional Regulation of Serotonin Receptors

血清素受体的转录后调节

基本信息

批准号：
7010646
负责人：
Ronald B. Emeson
金额：
$ 33.91万
依托单位：
VANDERBILT UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
1997
资助国家：
美国
起止时间：
1997-02-01 至 2008-01-31
项目状态：
已结题

项目摘要

DESCRIPTION (provided by applicant): Serotonin (5-hydroxytryptamine; 5-HT) is a monoaminergic neurotransmitter that modulates numerous sensory and motor processes as well as a wide variety of behaviors including sleep, appetite, pain perception, locomotion, thermoregulation, hallucinations, and sexual behavior. Recent studies from our laboratory have indicated that the function of the 2C-subtype of serotonin receptor (5-HT2 c R) is modulated by a novel RNA modification process referred to as RNA editing. Editing of 5-HL2cR transcripts is responsible for the tissue-specific expression of as many as twenty-four 5-HT2cR isoforms and is proposed to represent a regulatory mechanism by which cells modulate their response to extracellular signals by altering the efficacy and specificity of receptor/G-protein interactions; the long term objectives of the proposed research are to define the cellular mechanisms involved in the regulation of serotonergic signal transduction in the central nervous system. We propose to examine the signaling properties of distinct 5-HT2cR isoforms using a high-throughput, cell-based assay to identify functional interactions between 5-HT, cR isoforms and the a-subunits of several heterotrimeric G-proteins. These studies will be extended to examine the functional responses of other edited 5-HT2cR isoforms that are highly expressed in the rat and human brain and to dissect the 5-HT2cR-activated signaling pathways leading to activation of phospholipase D, mitogenactivated (MAP) kinase and rearrangements of the actin cytoskeleton. To examine the physiological relevance of multiple, edited 5-HT2cR isoforms, mice capable of expressing only, a single 5-HT2CR isoform will be generated by targeted gene modification in embryonic stem cells; the non-edited (INI) and fully-edited (VGV) 5-HT2c R isoforms have been selected for these studies, as they demonstrate the greatest differences in receptor: G-protein coupling efficacy In additional to gross alterations in animal phenotype and brain morphology, mutant mice will be examined for alterations in physiological systems in which the 5-HT2cR has already been implicated, including tumorigenesis, seizure activity, feeding behavior, locomotor activity and hippocampal function. To further examine the role of 5-HT2cR editing in cellular transformation, NIH-3T3 cells expressing specific 5-HT2cR isoforms will be assessed for a number of transformed cellular characteristics including increased mitogenesis, loss of contact inhibition, loss of anchorage dependence and the ability to generate tumors in nude mice. It is anticipated that these studies will provide new insights concerning the regulation of cellular processes involved in the transduction of serotonergic signals and the role(s) of multiple serotonin receptors in the nervous system.

描述（由申请人提供）：血清素（5-羟色胺；5-HT）是一种调节多种感觉和运动的单胺能神经递质过程以及各种行为，包括睡眠、食欲、疼痛知觉、运动、体温调节、幻觉和性行为。我们实验室最近的研究表明，该功能 5-羟色胺受体 (5-HT2 c R) 的 2C 亚型由一种新型 RNA 调节修饰过程称为RNA编辑。 5-HL2cR 转录本的编辑负责多达二十四个的组织特异性表达 5-HT2cR 亚型并被提议代表一种调节机制，通过该机制细胞通过改变功效来调节其对细胞外信号的反应以及受体/G蛋白相互作用的特异性；的长期目标拟议的研究旨在定义参与的细胞机制中枢神经系统血清素信号转导的调节。我们建议检查不同 5-HT2cR 亚型的信号传导特性使用高通量、基于细胞的测定来识别功能相互作用 5-HT、cR 同工型和几个异源三聚体的 a 亚基之间 G-蛋白。这些研究将扩展到检查功能反应在大鼠和人类中高度表达的其他编辑的 5-HT2cR 亚型大脑并剖析 5-HT2cR 激活的信号通路导致磷脂酶 D、丝裂原激活 (MAP) 激酶的激活和重排肌动蛋白细胞骨架。为了检查多个经过编辑的 5-HT2cR 同工型的生理相关性，只能够表达单一5-HT2CR亚型的小鼠将通过以下方式产生胚胎干细胞的靶向基因修饰；未编辑的 (INI) 和这些研究已选择完全编辑 (VGV) 5-HT2c R 同工型，如它们表现出最大的差异在于受体：G蛋白偶联功效除了动物表型和大脑的总体改变之外形态学方面，将检查突变小鼠的生理变化已涉及 5-HT2cR 的系统，包括肿瘤发生、癫痫活动、进食行为、运动活动和海马体功能。为了进一步研究 5-HT2cR 编辑在细胞转化中的作用，将评估表达特定 5-HT2cR 同种型的 NIH-3T3 细胞一些转化的细胞特征，包括增加有丝分裂，失去接触抑制、失去锚定依赖性和能力在裸鼠体内产生肿瘤。预计这些研究将提供关于参与细胞过程调节的新见解血清素信号的转导和多种血清素的作用神经系统中的受体。