Post-transcriptional Regulation of Serotonin Receptors

性状（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 过程以及各种各样的行为，包括睡眠，食欲， 疼痛感知、运动、体温调节、幻觉和性行为 行为我们实验室最近的研究表明， 5-羟色胺受体（5-HT 2 c R）的2C亚型由一种新的RNA调节 这一过程被称为RNA编辑。5-HL 2cR转录本的编辑 负责多达24种 5-HT 2cR亚型，并提出代表一种调节机制， 细胞通过改变其功效来调节其对细胞外信号的反应 和受体/G蛋白相互作用的特异性; 拟议的研究是为了确定参与的细胞机制， 调节中枢神经系统中的多巴胺能信号转导。 我们建议研究不同的5-HT 2cR亚型的信号传导特性 使用高通量、基于细胞的测定来鉴定功能性相互作用 5-HT，cR亚型和几种异源三聚体的α-亚基之间的关系 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-HT 2cR同种型 大脑和解剖5-HT 2cR激活的信号通路，导致 磷脂酶D、丝裂原活化（MAP）激酶和重排的活化 肌动蛋白细胞骨架。 为了检查多种编辑的5-HT 2cR亚型的生理相关性， 仅能表达单一5-HT 2CR同种型的小鼠将通过 胚胎干细胞中的靶向基因修饰;非编辑（INI）和 这些研究选择了完全编辑的（VGV）5-HT 2c R亚型， 它们在受体：G蛋白偶联方面表现出最大的差异 除了动物表型和脑的总体变化外， 形态学，将检查突变小鼠的生理学改变， 5-HT 2cR已经涉及的系统，包括 肿瘤发生、癫痫发作活动、进食行为、运动活动和 海马功能 为了进一步研究5-HT 2cR编辑在细胞转化中的作用， 将评估表达特异性5-HT 2cR亚型的NIH-3 T3细胞的 转化的细胞特征的数量，包括增加的有丝分裂， 接触抑制的丧失、锚定依赖性的丧失和 在裸鼠体内产生肿瘤。预计这些研究将提供 新的见解有关的细胞过程的调节参与 β-羟色胺能信号的转导和多种5-羟色胺的作用 神经系统中的受体。

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.