Post-transcriptional Regulation of Serotonin Receptors

描述(申请人提供)：5-羟色胺(5-羟色胺；5-羟色胺)是一种 调节多种感觉和运动的单胺能神经递质 以及各种各样的行为，包括睡眠，食欲， 痛觉、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，这一功能 其中2C亚型的5-羟色胺受体(5-HT2c-R)受一种新的RNA调控 修饰过程称为RNA编辑。编辑5-HL2cR转录本 负责组织特异性表达多达24个 5-HT2cR亚型，被认为是一种调节机制，通过这种机制 细胞通过改变药效来调节它们对细胞外信号的反应 和受体/G蛋白相互作用的特异性；长期目标 这项拟议的研究是为了定义参与细胞机制的 中枢神经系统中5-羟色胺能信号转导的调节。 我们建议研究不同的5-HT2cR亚型的信号特性 使用高通量、基于细胞的分析来确定功能相互作用 在5-羟色胺、铬异构体和几种杂三聚体的α-亚基之间 G蛋白。这些研究将扩展到检查功能性反应 在大鼠和人中高表达的其他编辑的5-HT2cR亚型 并剖析5-HT2cR激活的信号通路导致 磷脂酶D、丝裂原活化(MAP)激酶的激活和重排 肌动蛋白细胞骨架。 为了检查多种编辑的5-HT2cR亚型的生理学相关性， 只能表达的小鼠，将通过以下方式产生单个5-HT2CR亚型 胚胎干细胞的靶向基因修饰；未编辑的(INI)和 这些研究选择了完全编辑的(VGV)5-HT2C R亚型，如 它们在受体上表现出最大的差异：G蛋白偶联 动物表型和脑的大体改变以外的疗效 形态，突变小鼠将被检查生理上的变化 已经涉及5-HT2cR的系统，包括 肿瘤发生、癫痫发作、摄食行为、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， 表达特定5-HT2cR亚型的NIH-3T3细胞将被评估为 转化的细胞特征的数量，包括增加有丝分裂， 丧失接触抑制，丧失对锚定的依赖，并能够 在裸鼠身上产生肿瘤。预计这些研究将提供 关于细胞过程调控的新见解 5-羟色胺能信号转导与多重5-羟色胺的作用(S) 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.