CGG repeat associated translation in Fragile X-associated Tremor/Ataxia Syndrome

脆性 X 相关震颤/共济失调综合征中的 CGG 重复相关翻译

基本信息

批准号：
9914611
负责人：
Peter K Todd
金额：
$ 47.32万
依托单位：
UNIVERSITY OF MICHIGAN AT ANN ARBOR
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-04-01 至 2024-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9914611
关键词：
5&apos Untranslated Regions Address Affect Biochemical Biological Models Brain Brain Diseases Bypass CGG repeat Cell Line Cellular Stress Complex Data Degenerative Disorder Disease Disease model Drosophila genus Event Excision FMR1 FXTAS Fragile X Gene Genetic Goals Human Impairment Inherited Initiator Codon Initiator tRNA Intervention Knock-out Location Mediating Monitor Mus Mutation Nerve Degeneration Neurodegenerative Disorders Neurons Nucleotides Open Reading Frames Pathogenesis Pathogenicity Pathway interactions Patients Peptide Initiation Factors Peptides Phenotype Phosphorylation Phosphotransferases Play Process Production Protein Biosynthesis Protein Kinase Proteins RNA Reading Frames Recycling Reporter Ribosomes Role Scanning Series Stress Stress Tests Symptoms Techniques Testing Therapeutic Tissues Toxic effect Translating Translation Initiation Translations Ubiquitin Viral Virus Diseases age related base biochemical tools biological adaptation to stress induced pluripotent stem cell innovation mouse model nervous system disorder novel novel therapeutics prevent protein aggregation ran GTP-Binding Protein response stem cell model stress granule therapeutic target tool

项目摘要

Fragile X-associated tremor/Ataxia syndrome (FXTAS) is one of a large class of human neurological disorders that result from instability and expansion of nucleotide repeats. In FXTAS, a CGG nucleotide repeat expands in the 5’ untranslated region of the fragile X gene, FMR1, and triggers formation of aggregated protein inclusions in the patient brains. Our group found that the FXTAS CGG repeat gets translated into toxic homopolymeric proteins despite its location outside of a canonical open reading frame through a process known as repeat associated Non-AUG initiated (RAN) translation. RAN translated proteins accumulate in patient tissues and contribute to CGG repeat associated toxicity in multiple model systems. In this proposal, we will explore how this alternative translational initiation occurs mechanistically. Our preliminary data suggests that RAN translation at CGG repeats is selectively enhanced by cellular stress, which typically blocks protein synthesis. In parallel, CGG repeats directly elicit cellular stress and trigger stress granule formation. Our central hypothesis is that CGG RAN translation and cellular stress participate in a feed-forward loop that drives neurodegeneration. Our collaborative team will directly test this hypothesis by using biochemical techniques as well as drosophila, mouse and human induced pluripotent stem cell models of FXTAS. In Aim 1 we will determine how cellular stress selectively activates RAN translation, focusing specifically on initiation factors that underlie this process. In Aim 2, we will elucidate how CGG repeats elicit cellular stress and influence stress granule dynamics and whether interventions in this process impact repeat toxicity. In Aim 3, we will test whether selective blockade of cellular stress pathways can disrupt this feed forward loop and alleviate CGG repeat associated toxicity across disease models. Together, these studies will illuminate critical events in the pathogenesis of FXTAS and other nucleotide repeat expansion disorders while rigorously testing two complementary & innovative approaches to selective RAN translation blockade.

脆性 X 相关震颤/共济失调综合征 (FXTAS) 是一大类人类神经系统疾病之一这是由核苷酸重复序列的不稳定和扩展引起的。在 FXTAS 中，CGG 核苷酸重复序列会扩展。脆弱 X 基因 FMR1 的 5' 非翻译区，并触发聚集蛋白内含物的形成我们的小组发现 FXTAS CGG 重复序列被转化为有毒的均聚物。尽管蛋白质通过称为重复的过程位于规范开放阅读框之外相关的非 AUG 启动 (RAN) 翻译蛋白在患者组织中积累，并且在本提案中，我们将探讨如何在多个模型系统中促进 CGG 重复相关毒性。我们的初步数据表明，这种替代性翻译起始是机械发生的。 CGG 重复序列的翻译会通过细胞应激选择性增强，细胞应激通常会阻碍蛋白质合成。与此同时，CGG 重复直接引发细胞应激并触发应激颗粒的形成。假设是 CGG RAN 翻译和细胞应激参与驱动前馈循环我们的合作团队将使用生化技术直接检验这一假设。以及 FXTAS 的果蝇、小鼠和人类诱导多能干细胞模型。确定细胞应激如何选择性激活 RAN 翻译，特别关注起始因子在目标 2 中，我们将阐明 CGG 重复如何引起细胞应激影响。在目标 3 中，我们将测试应激颗粒动力学和干预措施是否会影响重复毒性。选择性阻断细胞应激途径是否可以破坏这种前馈循环并减轻 CGG 这些研究将共同阐明疾病模型中的关键事件。 FXTAS 和其他核苷酸重复扩增疾病的发病机制，同时严格测试两种选择性 RAN 翻译封锁的互补和创新方法。