Role of miRNA Argonautes in organismal aging

项目总结 调控RNA几乎控制着每一条生物途径，这一发现彻底改变了我们的 过去十年对基因表达的理解。在最前沿，microRNAs(MiRNAs)具有 已被证明是植物和动物中一种丰富和必要的RNA分子。这个 越来越多的人认识到miRNAs在人类生物学中的重要性 特定miRNA途径的错误调控会导致复杂的疾病，包括癌症、心脏 疾病和神经病理。MiRNAs依赖于ArgAerte(AGO)蛋白结合和 在转录后水平调控靶基因的表达。在线虫中，古人就像 基因1和2(ALG-1、ALG-2)蛋白在氨基酸水平和功能上有85%以上的相似性 在开发过程中多余的。然而，在成年后，这些前辈扮演着相反的角色，比如 1或alg-2突变体分别表现出寿命缩短或延长。此外，健康范围，如 以最大速度衡量，在alg-1中减少，在alg-2突变体中增加 野性的成虫。其中一条长寿路径会受到两种疾病的不同影响： 胰岛素/胰岛素样生长因子-1信号传导(IIS)。这些初步研究导致了一种假设，即 Alg-1和alg-2的表达或活性允许它们调节IIS中不同的基因集 控制成年动物寿命的途径。在目标1和目标2中，遗传基础和潜在组织 负责alg-1和alg-2相反长寿功能的具体活动将是 下定决心。检测ALG-1结合的特异性miRNAs和靶点的前沿方法 而ALG-2将在AIM 3中使用。这将导致第一个miRNA特定靶点的图谱 并对alg-1和alg-2在IIS中的直接作用提供了前所未有的见解，以及 也许还有其他长寿途径。此外，通过揭示miRNA在成人中的靶向景观 线虫将建立一个新的基础来研究保守的miRNA和 其他物种的目标。这项研究的另一个广泛影响是它将揭示两种蛋白质如何 认为在老龄化中扮演相反角色是多余的，这将为考虑 上下文对于任何途径中相关基因功能的重要性。此外，这些方法 这里用来识别miRNA特定靶点的方法通常适用于整个系统，因此， 将有助于消除将miRNAs与其内源性靶点匹配的长期障碍。 最后，这项工作的一个长期目标是有助于合理设计修改基因的策略 旨在预防或对抗与年龄有关的疾病的言论。

PROJECT SUMMARY The discovery that regulatory RNAs control almost every biological pathway has revolutionized our understanding of gene expression over the past decade. At the forefront, microRNAs (miRNAs) have proven to be an abundant and essential class of RNA molecules in plants and animals. The importance of miRNAs in human biology is highlighted by the increasing recognition that misregulation of specific miRNA pathways contributes to complex diseases, including cancer, heart ailments and neuronal pathologies. MiRNAs depend on Argonaute (AGO) proteins to bind and regulate the expression of target genes at the post-transcriptional level. In C. elegans, the AGO Like Genes 1 and 2 (ALG-1, ALG-2) proteins are over 85% identical at the amino acid level and function redundantly during development. However, at adulthood these AGOs take on opposing roles, as alg- 1 or alg-2 mutants exhibit shortened or extended lifespans, respectively. Additionally, healthspan, as measured by maximum velocity, is reduced in alg-1 and increased in alg-2 mutants compared to wildtype adults. One longevity pathway that is differentially impacted by the loss of either AGO is Insulin/ IGF-1 Signaling (IIS). These preliminary studies lead to the hypothesis that differences in the expression or activity of alg-1 and alg-2 allow them to regulate distinct sets of genes in the IIS pathway to control lifespan in adult animals. In Aims 1 and 2, the genetic basis and potential tissue specific activities responsible for the opposing longevity functions of alg-1 and alg-2 will be determined. Cutting edge methods for detecting the specific miRNAs and targets bound by ALG-1 and ALG-2 will be utilized in Aim 3. This will result in the first map of miRNA specific target sites in an adult animal and provide unprecedented insights into the direct roles of alg-1 and alg-2 in the IIS, and perhaps other, longevity pathways. Furthermore, by revealing the miRNA targeting landscape in adult C. elegans a new foundation will be set for investigating longevity roles for conserved miRNAs and targets in other species. Another broad impact of this study is that it will reveal how two proteins considered redundant take on opposing roles in aging, which will provide a paradigm for considering the importance of context for the function of related genes in any pathway. Additionally, the methods used here to identify miRNA specific target sites are generally applicable across systems and, thus, will help eliminate a longstanding barrier to matching miRNAs with their endogenous target sites. Finally, a long-term goal of this work is to contribute to the rational design of strategies to modify gene expression with the intention of preventing or counteracting age-related maladies.