MOLECULAR ROLE OF RIGUI IN MAMMALIAN CIRCADIAN PATHWAY

描述：哺乳动物生物钟的分子组成是 难以捉摸。 申请人已经分离了一种名为RIGUI的人基因，其编码 一种bHLH/PAS蛋白，与果蝇的period基因有44%的同源性。 高度保守的小鼠同源物（m-rigui）在昼夜节律中表达， 视交叉上核（SCN）的模式， 哺乳动物的生物钟 SCN中的昼夜节律表达在 恒定的黑暗，在光明/黑暗周期的转变唤起了一个比例 SCN中m-rigui表达的移位。 m-rigui转录本也出现在 浦肯野神经元，结节部和视网膜的周期性模式，但与 振荡的定时不同于SCN中所见的定时。 鉴于 观察到RIGUI基因具有核心的所有已知特性， 主要研究者希望更好地定义昼夜节律成分 它在昼夜节律通路中的确切作用。 本研究的具体目的 a）识别特定的大脑和外周组织，其中各种 昼夜节律振荡器存在; B）确定褪黑激素是否在 m-rigui在垂体结节部的表达; c）调查 m-rigui在视网膜和视交叉上核的表达反应 d）对m-rigui进行有针对性的破坏 基因敲除方法，并确定其损失对 动物的昼夜节律行为; e）鉴定编码蛋白质的基因 使用双混合动力系统与RIGUI交互; f）确定 人RIGUI基因座的基因组结构并描绘其启动子， 顺式作用元件。 了解日归的遗传学和分子基础 功能可能会导致新的范例，基因如何控制哺乳动物 行为

DESCRIPTION: The molecular components of mammalian circadian clocks are elusive. The applicant has isolated a human gene termed RIGUI that encodes a bHLH/PAS protein 44 percent homologous to the period gene in Drosophila. The highly conserved mouse homolog (m-rigui) is expressed in a circadian pattern in the suprachiasmatic nucleus (SCN), the master regulator of circadian clocks in mammals. Circadian expression in the SCN continues in constant darkness, and a shift in the light/dark cycle evokes a proportional shift of m-rigui expression in the SCN. m-rigui transcripts also appear in a periodic pattern in Purkinje neurons, pars tuberalis, and retina, but with a timing of oscillation different from that seen in the SCN. Given the observation that the RIGUI gene has all the properties known about a core circadian component the principal investigator would like to define better its exact role in the circadian pathway. The specific aims of this study are to: a) Identify specific brain and peripheral tissue where the various circadian oscillators reside; b) Determine whether melatonin plays a role in the expression of m-rigui in the hypophyseal pars-tuberalis; c) Investigate the response of m-rigui expression in the retina and suprachiasmatic nucleus to environmental light cues; d) Make the targeted disruption of the m-rigui locus by gene knock-out methodology and determine the effect of its loss on the circadian behavior of the animals; e) Identify genes encoding proteins that interact with RIGUI using the two-hybrid system; f) Determine the genomic structure of the human RIGUI locus and delineate its promoter and cis-acting elements. Understanding genetics and molecular basis of RIGUI function could lead to new paradigms on how genes control mammalian behavior.