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）：5-羟色胺（5-羟基丙胺； 5-HT）是一个单胺能神经递质调节许多感觉和运动过程以及各种各样的行为，包括睡眠，食欲，疼痛感，运动，体温调节，幻觉和性行为。我们实验室的最新研究表明该功能 5-羟色胺受体（5-HT2 C R）的2C-囊型由新型RNA调节修改过程称为RNA编辑。 5-HL2CR笔录的编辑负责多达二十四的组织特异性表达 5-HT2CR同工型，并建议代表一种调节机制细胞通过改变功效来调节其对细胞外信号的反应受体/G蛋白相互作用的特异性；长期目标的拟议的研究是定义与调节中枢神经系统中血清素能信号转导的调节。我们建议检查不同的5-HT2CR同工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在5-HT，CR同工型和几种异三聚体的A-亚基特之间 G蛋白。这些研究将扩展以检查功能响应在大鼠和人类中高度表达的其他编辑的5-HT2CR同工型中大脑并剖析5-HT2CR激活的信号通路，导致磷脂酶D的激活，有丝分裂激活（MAP）激酶和重排肌动蛋白细胞骨架。检查多个编辑的5-HT2CR同工型的生理相关性，只能表达的小鼠，将会由单个5-HT2CR同工型产生胚胎干细胞中的靶向基因修饰；未编辑（INI）和已经选择了全面编辑的（VGV）5-HT2C R同工型用于这些研究，如他们证明了受体最大的差异：G蛋白耦合动物表型和大脑的总体改变的功效形态学，突变小鼠的生理改变将检查 5-HT2CR已经牵涉到的系统，包括肿瘤发生，癫痫活性，进食行为，运动活性和海马功能。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同工型的NIH-3T3细胞。转化的细胞特征数量，包括有丝分裂的增加，接触抑制的丧失，锚定依赖的丧失和能力在裸鼠中产生肿瘤。预计这些研究将提供有关调节涉及细胞过程的新见解血清素能信号的转导和多种5-羟色胺的作用神经系统中的受体。