Identification of longevity targets in C. elegans protein translation mutants

描述（由申请人提供）：本奖学金申请中提出的研究解决了衰老和mRNA翻译领域中一个非常有趣的问题：为什么许多生物体，包括在mRNA翻译机制的关键组件中存在缺陷的线虫，都是长寿和抗应力的？有趣的是，为了应对环境压力，所有真核细胞都关闭了它们的生物合成活性，并进行了综合应激反应。在恢复过程中，某些蛋白质是在翻译抑制的背景下产生的。本应用的主要目的是揭示在应激反应中使应激诱导mrna从翻译抑制中逃脱的生化机制，以及参与长寿表型的主动翻译mrna。该项目将检验属于S6激酶（S6K）和/或真核翻译起始因子（eIFs）组的关键翻译调节因子可以特异性介导这种逃逸的假设。研究的重点将放在risk -1/ S6K和life -2/eIF4E上，后者是蠕虫体内的5种同工异构体之一，是一种mRNA 5'-cap结合蛋白。S6K和eIF4E可能都是调节应激特异性和长寿翻译途径的核心。需要解决的主要问题是：需要合成哪些S6K和eIF4E下游翻译靶标才能在压力和衰老下存活？这个问题将解决与一系列尖端的核糖组学和蛋白质组学方法使用线虫，秀丽隐杆线虫作为实验系统。模式生物由于其发育迅速、寿命短，并且能够通过RNAi轻松敲除基因，因此对衰老研究非常有用。

DESCRIPTION (provided by applicant): The research proposed in this fellowship application addresses an extremely interesting question in the field of aging and mRNA translation: How come many organisms, including the nematode C. elegans defective in key components of the mRNA translational machinery are long-lived and stress resistant? Interestingly, in response to environmental stress, all eukaryotic cells shut down their biosynthetic activity and mount an integrated stress response. During recovery, certain proteins are produced against the backdrop of general translational repression. The main objective of the present application is to uncover the biochemical mechanisms that enable the escape of stress-induced mRNAs from translational repression during the stress response and the actively translated mRNAs involved in the longevity phenotype. The project will examine the hypothesis that key translational regulatory factors belonging to either S6 kinase (S6K) and/or the group of eukaryotic translation initiation factors (eIFs) can specifically mediate this escape. The focus will be on rsks-1/ S6K, as well as on ife-2/eIF4E, one of five isoforms in worms that is an mRNA 5'-cap binding protein. Both S6K and eIF4E may be at the heart of regulating a pathway that mediates stress-specific and longevity translation. The main question to be addressed is: What are S6K and eIF4E downstream translational targets that need to be synthesized in order to allow survival under stress and aging? This question will be addressed with a series of cutting-edge ribonomic and proteomic approaches using the nematode, C. elegans as an experimental system. The model organism is extremely useful for aging research because of its rapid development, short lifespan, and the ability to knock-out genes through RNAi with great ease. PUBLIC HEALTH RELEVANCE: Population aging is progressing rapidly and is having a profound global demographic trend in the twenty-first century. However, this progression is poorly understood at both the cellular and molecular level. This proposal aims to determine how mRNA translation, which is a tightly regulated cellular process that affects an organism during growth, reproduction, as well as survival in response to nutrient availability and energy levels, modulates organismal aging and stress resistance. As an age-related decline in protein synthesis rate is observed in many organisms, this research might have direct relevance for understanding the role of protein synthesis in human aging.