Ribosomal RNA methylation regulation of longevity and stress resistance

项目摘要 该项目的目标是了解核糖体RNA甲基化如何调节特异性转录因子的翻译。 调节衰老的蛋白质。蛋白质组的破坏是衰老的标志。有表达能力 对环境信号作出反应的适当蛋白质是一种必需的、进化上保守的蛋白质， 过程因此，保存蛋白质组对于维持生物体健康和健康衰老至关重要。 然而，衰老应答mRNA如何选择性翻译尚不清楚。我们最近发现， 核糖体RNA甲基化可以促进特定蛋白质子集的翻译。另外我们 表征了核糖体占有率如何随着有机体年龄的变化而变化，并确定 核糖体DNA甲基化足以预测生物体的年龄。核糖体RNA甲基化 随着生物体的衰老，蛋白质组在保持蛋白质组完整性方面的作用仍不清楚。我们最近发现， 调节RNA甲基化的酶和RNA甲基化本身在衰老过程中失调， 对压力的反应。我们发现N6-腺苷甲基转移酶METL-5直接甲基化腺苷 1717在C.优雅腺苷1717的甲基化增强核糖体结合， 选择性翻译特定的mRNA。我们的初步数据显示metl-5缺陷动物生长 通常在稳态条件下;然而，metl-5突变体对多种胁迫具有抗性， 包括热休克和紫外线照射。因此，METL-5对18 S rRNA的特定残基的甲基化 选择性地增强特定转录物的翻译以调节应激抗性。不管rRNA 甲基化可以更广泛地调节年龄和应激反应的翻译，这种失调是否 驱动器的老化过程仍然是未知的。通过进行定向RNAi筛选，我们鉴定了额外的rRNA， 甲基转移酶，当缺失时增加C. elegans寿命。这些初步调查结果表明， 核糖体RNA甲基化可以促进特异性转录物的选择性翻译，提供另一层 调节应激反应和衰老。利用这些初步数据，我们将使用基因， 生物化学和分子生物学方法，在体外和体内解剖rRNA甲基化的作用， 调节老化和抗应力。我们的基本假设是rRNA甲基化促进核糖体 对应激条件和衰老反应的异质性，以促进应激的适当转化 耐药性转录本。

Project Summary The goal of this project is to understand how ribosomal RNA methylation can regulate translation of specific proteins to regulate aging. Disruption of the proteome is a hallmark of aging. Having the capacity to express the appropriate protein in response to environmental cues is an essential and evolutionarily conserved process. Therefore, preserving the proteome is critical for maintaining organismal health and healthy aging. However, how aging-responsive mRNAs are selectively translated is unknown. We recently identified that ribosomal RNA methylation could facilitate the translation of a specific subset of proteins. Additionally, we characterized how ribosome occupancy changes as an organism ages and determined that changes in ribosomal DNA methylation are sufficient to project the organismal age. Whether ribosomal RNA methylation plays a role in preserving proteome integrity as organisms age is still unclear. We have recently found that enzymes which regulate RNA methylation and RNA methylation itself are dysregulated during aging and in response to stress. We found that an N6-adenosine methyltransferase, METL-5, directly methylates adenosine 1717 on 18S ribosomal RNA in C. elegans. Methylation of adenosine 1717 enhances ribosomal binding and selective translation of specific mRNAs. Our preliminary data shows that metl-5 deficient animals grow normally under homeostatic conditions; however, metl-5 mutants are resistant to a variety of stresses, including heat shock and UV irradiation. Thus, methylation of a specific residue of 18S rRNA by METL-5 selectively enhances translation of specific transcripts to regulate stress resistance. However, whether rRNA methylation more broadly can regulate age and stress-responsive translation and whether this dysregulation drives the aging process is still unknown. By performing a directed RNAi screen, we identified additional rRNA methyltransferases that when deleted increase C. elegans lifespan. These preliminary findings suggest that ribosomal RNA methylation can facilitate selective translation of specific transcripts providing another layer of regulation of the stress response and aging. Capitalizing on this preliminary data we will use genetic, biochemical, and molecular approaches both in vitro and in vivo to dissect the role of rRNA methylation in regulating aging and stress resistance. Our underlying hypothesis is that rRNA methylation promotes ribosome heterogeneity in response to stress conditions and aging to facilitate the appropriate translation of stress resistance transcripts.