Defining the role for Gle1 in the fetal lethal motor neuron disease LCCS1

描述(申请人提供)：信使RNA(MRNAs)的核输出及其随后的翻译是基因表达途径中必不可少的步骤，影响细胞生理的方方面面。越来越多的证据表明，功能障碍的mRNA运输直接导致运动神经元病(MND)。最近突变的人类GLE1等位基因与胎儿运动神经元疾病：致死性先天性收缩综合征(LCCS-1)的遗传联系进一步支持了这一点。Gle1是一种必需的信使核糖核酸输出因子，从酵母到人类都是保守的。酵母Gle1在翻译的启动和终止中都起着重要的作用。对LCCS-1病例基因组DNA的序列分析发现了一种突变，该突变在GLE1的第三内含子内产生了一个不合法的剪接受体位点。这种特殊的突变(FINmain)导致在hGle1的氨基末端插入三个氨基酸残基(PFQ)。在初步研究中，hGle1在细胞质mRNA转运中的一种新功能已被发现。值得注意的是，FIN主要突变可能会破坏hGle1‘S在人口贩运中的功能。这项建议的目的是阐明FIN主要突变蛋白在哺乳动物细胞中的功能后果。提出的两个目标将定义FIN主要突变的分子后果。在目标I中，将进行研究，将hGle1定义为细胞质mRNA运输机制的一个组成部分。在AIM II中，将开发一种新的hGle1基因敲除和加回模型系统。在这个实验模型中，细胞生物学和生化分析将被用来调查FIN主要突变蛋白是否中断了mRNA的运输。长期目标是从分子上确定hGle1在有害疾病lccs-1发病机制中的神经元作用。 与公共健康相关：Gle1被定位为在mRNA代谢和基因表达过程中调节多个步骤。通过定义FIN主要突变的分子功能后果，我们将阐明RNA代谢在运动神经元病中的重要性。

DESCRIPTION (provided by applicant): Nuclear export of messenger RNAs (mRNAs) and their subsequent translation are essential steps in the gene expression pathway and impact all aspects of cell physiology. There is a growing body of evidence suggesting that dysfunctional mRNA trafficking contributes directly to motor neuron diseases (MND). This is further supported by the recent genetic linkage of mutant human GLE1 alleles to the fetal motor neuron disease: Lethal Congenital Contracture Syndrome (LCCS-1). Gle1 is an essential mRNA export factor, conserved from yeast to humans. Yeast Gle1 plays an important role in both translation initiation and termination. Sequence analysis of genomic DNA from LCCS-1 cases identified a mutation that generates an illegitimate splice acceptor site within the third intron of GLE1. This specific mutation (FINMajor) results in an insertion of three amino acid residues (PFQ) in the amino-terminal domain of hGle1. In preliminary studies a novel function for hGle1 in cytoplasmic mRNA trafficking has been found. Strikingly, the FINMajor mutation may disrupt hGle1's function in trafficking. The goal of this proposal is to elucidate the functional consequence of the FINMajor mutant protein in mammalian cells. The two aims proposed will define the molecular consequence of the FINMajor mutation. In Aim I, studies will be done to define hGle1 as a component of the cytoplasmic mRNA trafficking machinery. In Aim II, a novel hGle1 knockdown, and add-back model system will be developed. With this experimental model, cell biology and biochemical assays will be used to investigate if the FINMajor mutant protein disrupts mRNA trafficking. The long-term goal is to molecularly define the neuronal role for hGle1 in the pathogenesis of the deleterious disease LCCS-1 PUBLIC HEALTH RELEVANCE: Gle1 is positioned to regulate multiple steps during mRNA metabolism and gene expression. By defining the molecular functional consequence of the FINMajor mutation, we will elucidate the importance of RNA metabolism in motor neuron disease.