Dissecting the genetic and molecular networks underlying longevity and aging

 描述(由申请人提供)：简化的胰岛素/IGF-1样信号(IIS)通过依赖于保守的转录因子DAF-16/FOXO的机制上调应激反应(I类)和下调发育(II类)基因来延长线虫的寿命。通过将全基因组对DAF-16基因表达反应性的分析与全基因组转录因子的体内结合数据相结合，我们发现转录激活因子PQM-1通过与DAF-16相关元件(DAE)结合直接控制II类基因。DAF-16只通过DAF-16结合元件(DBE)直接调控I类基因。PQM-1的缺失抑制了daf-2和Eat-2的寿命以及耐热性，并进一步减缓了发育。PQM-1和DAF-16的核存在由IIS以相反的方式控制，令人惊讶的是，发现它们是相互排斥的。我们还观察到随着年龄的增长，核PQM-1的进行性丢失，解释了PQM-1靶标表达的下降。总而言之，我们的数据表明了一种在压力反应和发育之间切换的优雅机制。该项目的总体目标是阐明PQM-1和DAF-16之间观察到的拮抗关系的潜在机制。我们将使用基于报告分析和微流控显微镜的高通量筛选来鉴定PQM-1易位的遗传和小分子调节因子。此外，我们将使用质谱学来鉴定PQM-1‘S的翻译后修饰和蛋白质相互作用，并确定这些因素如何影响核转位。我们还将确定DAF-16和PQM-1随年龄增长而退出核的因素。最后，我们将在哺乳动物细胞中鉴定与FOXO表现出类似拮抗作用的PQM-1同源物。总之，我们的结果和见解将为理解PQM-1和DAF-16及其哺乳动物同行如何允许细胞在发育和应激反应之间取得平衡提供一个框架。

 DESCRIPTION (provided by applicant): Reduced insulin/IGF-1-like signaling (IIS) extends C. elegans lifespan by up-regulating stress response (Class I) and down-regulating development (Class II) genes through a mechanism that depends on the conserved transcription factor DAF-16/FOXO. By integrating a genomewide analysis of gene expression responsiveness to DAF-16 with genomewide in vivo binding data for a compendium of transcription factors, we discovered that the transcriptional activator PQM-1 directly controls Class II genes by binding to the DAF-16 associated element (DAE). DAF-16 directly regulates Class I genes only, through the DAF-16 binding element (DBE). Loss of PQM-1 suppresses daf-2 and eat-2 longevity as well as thermotolerance, and further slows development. The nuclear presence of PQM-1 and DAF- 16 is controlled by IIS in opposite ways, and, surprisingly, was found to be mutually exclusive. We also observe progressive loss of nuclear PQM-1 with age, explaining declining expression of PQM-1 targets. Together, our data suggest an elegant mechanism for switching between stress response and development. The overall goal of this project is to elucidate the mechanisms underlying the observed antagonistic relationship between PQM-1 and DAF-16. We will employ high-throughput screens based on reporter assays and microfluidics microscopy to identify genetic and small-molecule regulators of PQM-1 translocation. Additionally, we will use mass spectrometry to identify PQM-1's post-translational modifications and protein interactors, and determine how these affect nuclear translocation. We will also identify factors responsible for the nuclear exit of DAF-16 and PQM-1 with age. Finally, we will identify PQM-1 homologs in mammalian cells that exhibit a similar antagonism with FOXOs. Together, our results and insights will provide a framework for understanding how PQM-1 and DAF-16 and its mammalian counterparts allow cells to strike a balance between development and stress response.