Upstream open reading frames in neuronal function: a singular and genome-wide approach

神经元功能中的上游开放阅读框：单一的全基因组方法

• 批准号: 9234082
• 负责人: Caitlin Marie Rodriguez
• 金额: $ 3.47万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-03-01 至 2018-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9234082
• 关键词: 5' Untranslated Regions; Agonist; Area; Autistic Disorder; Biochemical; Bioinformatics; Biological Models; Biology; CGG repeat; Case Study; Cell Line; Clinical; Codon Nucleotides; Data; Disease; Emerging Technologies; Event; FMR1; FMR1 repeat; FMRP; FXTAS; Fragile X Syndrome; Future; Genes; Goals; Grant; Intellectual functioning disability; Intervention; Lead; Learning; Maps; Measures; Mediating; Memory; Messenger RNA; Nerve Degeneration; Neurobiology; Neurodegenerative Disorders; Neurodevelopmental Disorder; Neurons; Nucleotides; Open Reading Frames; Pathogenesis; Play; Positioning Attribute; Prevalence; Process; Production; Protein Biosynthesis; Proteins; RNA; Reporter; Research; Ribosomes; Role; Scanning; Series; Site; Stream; Structure; Synaptic plasticity; Techniques; Testing; Training; Transcript; Translating; Translational Regulation; Translations; Work; base; career; cellular imaging; channel blockers; gene product; genome-wide; insight; kainate; nervous system disorder; neuroblastoma cell; next generation sequencing; novel; polyglycine; public health relevance; response; ribosome profiling; synaptic function; transcriptome

 DESCRIPTION (provided by applicant): Neurons regulate when and where they synthesize new proteins to maintain basal and activity-dependent compartmental fidelity. Control of this process is largely regulated at translational initiation which typically occurs at the 5'-most AUG codon in an appropriate mRNA sequence context. Emerging data in simple model systems suggests that un-annotated, upstream open reading frames (uORFs) are utilized on a significant fraction of all transcripts. These uORFs often initiate at near-AUG (one base different from AUG) codons and display condition-dependent usage, suggesting they may play a regulatory role in translational control. How such atypical initiation events are mediated and what roles they play in neuronal function and disease are unknown. The central hypothesis of this grant is that upstream open reading frame usage is an important regulator of translational dynamics in neurons, and that proteins produced by translation from un-annotated uORFs will contribute to neuronal function. Our group recently discovered a novel mechanism for protein translational initiation associated with nucleotide repeats in the neurodegenerative disorder Fragile X-associated Tremor Ataxia Syndrome (FXTAS). FXTAS results from a CGG nucleotide repeat expansion in the 5' untranslated region (UTR) of the FMR1 gene. We discovered that this repeat expansion elicits initiation at a near-AUG codon in the 5'UTR, resulting in translation through the repeat via a process known as RAN (Repeat Associated Non-AUG) translation. This translation event leads to synthesis of a poly-glycine containing protein, FMRpolyG, even at normal repeat sizes. This proposal will first determine when FMRpolyG is synthesized in neurons both basally and in response to activity. Further, the impact of FMRpolyG synthesis on translation of the major FMR1 gene product, FMRP- a protein implicated in autism and intellectual disability will be assessed. To determine the prevalence of similar uORF utilization events in neurons, the novel next-generation sequencing technique known as ribosomal profiling will be used to measure ribosomal occupancy within 5'UTRs across the neuronal transcriptome. These studies will employ cellular imaging, biochemical and bioinformatics techniques to explore a new area in neurobiology with relevance to both synaptic plasticity as well as numerous neurological diseases.

 描述（由申请人提供）：神经元调节它们合成新蛋白质的时间和地点，以维持基础和活性依赖性区室保真度。该过程的控制主要在翻译起始处进行调节，翻译起始通常发生在适当的 5'-最 AUG 密码子处。简单模型系统中的新数据表明，所有转录本的很大一部分都使用了未注释的上游开放阅读框 (uORF)。 （与 AUG 不同的一个碱基）密码子并显示出条件依赖性使用，表明它们可能在翻译控制中发挥调节作用，这种非典型起始事件是如何介导的以及它们的作用是什么。 这项资助的核心假设是上游开放阅读框的使用是神经元翻译动力学的重要调节因素，并且通过未注释的 uORF 翻译产生的蛋白质将有助于神经元功能。研究小组最近发现了一种与神经退行性疾病脆性 X 相关震颤共济失调综合征 (FXTAS) 中的核苷酸重复相关的蛋白质翻译起始机制，该机制是由 CGG 核苷酸重复扩增引起的。 FMR1 基因的 5' 非翻译区 (UTR) 我们发现，这种重复扩展在 5'UTR 中的近 AUG 密码子处引发起始，从而导致通过 FMR1 基因的翻译。 通过称为 RAN（重复相关非 AUG）翻译的过程进行重复该翻译事件会导致含有聚甘氨酸的蛋白质 FMRpolyG 的合成，即使在正常的重复大小下，该提议也将首先确定 FMRpolyG 何时在神经元中合成。此外，还将评估 FMRpolyG 合成对主要 FMR1 基因产物 FMRP（一种与自闭症和智力障碍有关的蛋白质）翻译的影响，以确定患病率。为了研究神经元中类似的 uORF 利用事件，称为核糖体分析的新型下一代测序技术将用于测量神经元转录组中 5'UTR 内的核糖体占用情况。这些研究将采用细胞成像、生化和生物信息学技术来探索新的方法。神经生物学领域与突触可塑性以及许多神经系统疾病相关。