Lifespan extension by differential translation mediated by eIF-4G in C. elegans

线虫中 eIF-4G 介导的差异翻译延长寿命

• 批准号: 8113756
• 负责人: ARIC N ROGERS
• 金额: $ 8.83万
• 依托单位: BUCK INSTITUTE FOR RESEARCH ON AGING
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-04-01 至 2013-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8113756
• 关键词: 3' Untranslated Regions; Accounting; Address; Aging; Alternative Splicing; Animal Model; Attenuated; Binding; Bioinformatics; Biological; Biological Assay; Biological Models; Caenorhabditis elegans; Candidate Disease Gene; Characteristics; Computers; Data Set; Development; Diabetes Mellitus; Disease; Eukaryotic Initiation Factor-4G; Frequencies; Gene Expression Profile; Genes; Genetic; Genetic Epistasis; Genetic Translation; Goals; Health; Human; Length; Life; Longevity; Longevity Pathway; Maintenance; Malignant Neoplasms; Mammals; Mass Spectrum Analysis; Mediating; Mentors; Mentorship; Messenger RNA; Methods; MicroRNAs; Modeling; Monitor; Nematoda; Nerve Degeneration; Open Reading Frames; Orthologous Gene; Play; Process; Protein Biosynthesis; Proteins; Proteome; RNA Splicing; Regulation; Regulatory Element; Reporter; Research; Resistance; Ribosomes; Role; Scientist; Sequence Analysis; Small RNA; Source; Starvation; Testing; Transcript; Transgenic Animals; Translating; Translation Initiation; Translations; Untranslated Regions; Yeasts; age related; aging gene; attenuation; base; biological adaptation to stress; cell type; computerized data processing; genetic manipulation; genome-wide; in vivo; information gathering; mRNA Expression; novel; overexpression; tool

DESCRIPTION (provided by applicant): Although inhibition of translation initiation extends lifespan from yeast to mammals, the mechanism remains unknown. We showed that one of the most robust lifespan extension comes from suppression of ifg-1, the C. elegans ortholog of eukaryotic translation initiation factor (eIF)-4G, a factor that positively regulates translation. Previous studies have analyzed changes in total mRNA expression to investigate causes of lifespan changes under a number of different genetic and environmental conditions. However, other studies have shown large discrepancies between the transcriptome and proteome. I used translation state array analysis (TSAA), which accounts for post-transcriptional processing, to investigate changes upon direct modulation of translation by inhibiting ifg-1 expression. A large number of differentially translated mRNAs were found and ontological analysis revealed that upregulated genes included stress response genes and aging genes that are positive regulators of aging. Preliminary sequence analysis suggests that genes with preferentially maintained expression contain conserved characteristics known to modulate translation. qRT- PCR and quantitative mass spectroscopy corroborate TSAA results. Hypothesis: in addition to reducing global rates of translation, suppression of ifg-1 results in preferential translation of mRNA associated with stress response and somatic maintenance based on mRNA composition. An epistasis screen of 50 translationally enhanced stress response genes showed 10 that are required for maximal lifespan extension when ifg-1 is inhibited. I intend to a) directly determine translation changes and the impact of overexpression for these seven genes using in vivo reporter constructs, b) analyze sequences for known or novel cis- regulatory elements and isolate microRNAs (miRNAs) associated with differentially translated mRNAs, and c) characterize the miRNA and cis-regulatory elements for their effects between conditions as well as their roles in lifespan modulation 7. PUBLIC HEALTH RELEVANCE: Inhibition of translation extends lifespan across species. Simple model organisms like the nematode C. elegans provide powerful tools to uncover biological mechanisms that determine the beneficial effects of translation inhibition. Using C. elegans, I will examine how post-transcriptional processing is remodeled upon inhibition of translation initiation through the C. elegans ortholog of eukaryotic translation initiation factor 4G. Given the role played by deregulation of translation in age-related diseases including diabetes, cancer and neurodegeneration, this research has important implications for human health.

描述（由申请人提供）：虽然翻译起始的抑制延长了从酵母到哺乳动物的寿命，但其机制尚不清楚。我们发现，最强大的寿命延长之一来自于ifg-1的抑制，ifg-1是线虫真核翻译起始因子(eIF)-4G的同源物，这是一种积极调节翻译的因子。先前的研究分析了mRNA总表达的变化，以研究在许多不同的遗传和环境条件下寿命变化的原因。然而，其他研究表明转录组和蛋白质组之间存在巨大差异。我使用翻译状态阵列分析（TSAA），解释转录后处理，研究通过抑制ifg-1表达直接调节翻译的变化。大量差异翻译mrna被发现，本体论分析显示，上调的基因包括应激反应基因和衰老基因，它们是衰老的积极调节因子。初步的序列分析表明，优先维持表达的基因包含已知的调节翻译的保守特征。qRT- PCR和定量质谱证实了TSAA结果。假设：除了降低整体翻译率外，抑制ifg-1还会导致与应激反应和基于mRNA组成的体细胞维持相关的mRNA优先翻译。对50个翻译增强的应激反应基因的上位性筛选显示，当ifg-1被抑制时，10个基因需要最大限度地延长寿命。我打算a)使用体内报告构建直接确定这七个基因的翻译变化和过表达的影响，b)分析已知或新的顺式调控元件的序列，并分离与差异翻译mrna相关的microrna (miRNAs)，以及c)表征miRNA和顺式调控元件在不同条件下的影响以及它们在寿命调节中的作用7。