tRNA biology in healthy ageing: Functional differentiation and expression of tRNAiMet loci in Drosophila.

健康老龄化中的 tRNA 生物学：果蝇中 tRNAiMet 位点的功能分化和表达。

• 批准号: BB/Y000919/1
• 负责人: Nazif Alic
• 金额: $ 70.98万
• 依托单位: University College London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2024
• 资助国家: 英国
• 起止时间: 2024 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FY000919%2F1
• 关键词: tRNA; biology; healthy; ageing; Functional

The proportion of older people in our societies is rapidly increasing. For many, older age comes with increased frailty, impaired function and increased susceptibility to disease. The ageing of our populations is incurring massive personal and socioeconomic costs that need to be urgently addressed.Ageing itself can be modulated. Understanding this plasticity presents us with an opportunity to devise interventions to improve human health into old age. Importantly, directly targeting ageing has the potential for broad health improvements not limited to a single disease.This research project will answer a fundamental question in the biology of transfer RNAs (tRNAs) with strong relevance to ageing. tRNAs are the adaptor molecules universally used to translate the genetic code into proteins. Our interest in tRNA biology comes from our work on understanding the molecular mechanisms whereby the activity of a key regulator of cellular protein synthesis, the Target of Rapamycin Kinase Complex 1 (TORC1), promotes animal ageing. We found that TORC1 acts though RNA polymerase III, which itself is responsible for generating tRNAs. Hence, understanding tRNA biology will advance our knowledge of the ageing process.100s of tRNA genes are present in animal genomes, often as copies of identical sequence, complicating the analysis of their biology. Historically, such identical copies were thought to be simply redundant, providing multiple templates to facilitate high expression levels required for protein synthesis. However, there is growing appreciation that placing tRNA copies in different genomic contexts has allowed animals to finetune tRNA expression patterns thus diversifying organismal functions of identical or similar tRNAs. This hypothesis remains experimentally unaddressed due to lack of suitable animal models and genetic reagents, despite its fundamental importance. The fruit fly is a small animal but a powerful experimental model that has proven utility in understanding the basic biology of animals, including humans, and how they age. To start probing into the organismal roles of tRNAs, we focused on a tRNA specialised for initiation of protein synthesis, the initiator tRNAMet (tRNAiMet). We generated a set of fly mutants deleting copies of tRNAiMet from four different genomic locations. Our preliminary phenotyping revealed at least one tRNAiMet locus that contributes to ageing and indicated an interplay of unique and redundant organismal functions for the four loci. We will use this set of mutants, together with a set of reporter lines we have generated, to answer a fundamental question in tRNA biology, which will help us understand ageing: Why are multiple, identical copies of tRNA genes present throughout an animal's genome?Firstly, we will perform extensive phenotyping of single mutants and their combinations to identify organismal functions that are unique to certain loci as well as those that are redundant, with focus on ageing. Secondly, we will use reporter lines to assess the expression from each locus during development and in different adult tissues and organs. We will correlate the two sets of findings as well as integrate them by formally testing if unique expression patterns drive unique organismal functions. Thirdly, we will examine the role of tRNAiMet loci in the plasticity of ageing. Specifically, we will determine if longevity resulting from a reduction in nutrient intake or TORC1 inhibition is in part caused by changes in tRNAiMet levels.The project will answer a fundamental question in tRNA biology to provide us with a step change in understanding of tRNAs in the context of animal physiology. It will provide us with a pioneering insight into their role in animal ageing, as well as the knowledge required to decipher their organismal functions downstream of TORC1. In turn, this knowledge will inform interventions aimed at ensuring human health throughout the life course.

我们社会中老年人的比例正在迅速增加。对于许多年龄较大，脆弱，功能受损和对疾病的易感性提高。我们人口的衰老是要紧急解决的巨大个人和社会经济成本。了解这种可塑性为我们提供了制定干预措施以改善人类健康到老年的机会。重要的是，直接靶向衰老有可能进行广泛的健康改善，而不仅限于单一疾病。该研究项目将回答转移RNA（TRNA）（TRNA）的基本问题，与衰老相关。 TRNA是普遍用于将遗传代码转化为蛋白质的衔接分子。我们对tRNA生物学的兴趣源于我们了解分子机制的工作，从而促进动物衰老的雷帕霉素激酶复合物（TORC1）的靶标的细胞蛋白合成的关键调节剂的活性。我们发现TORC1用RNA聚合酶III起作用，该聚合酶III本身负责产生TRNA。因此，理解tRNA生物学将提高我们对衰老过程的了解。100s的tRNA基因存在于动物基因组中，通常是相同序列的副本，使其生物学的分析变得复杂。从历史上看，这种相同的副本被认为是简单的冗余，提供了多个模板以促进蛋白质合成所需的高表达水平。然而，越来越多的理解是将tRNA拷贝放在不同的基因组环境中，使动物能够捕获tRNA表达模式，从而使相同或相似tRNA的有机体功能多样化。由于缺乏合适的动物模型和遗传试剂，该假设在实验上仍未得到解决。果蝇是一种小动物，但是一种强大的实验模型，它证明了在了解包括人类在内的动物的基本生物学及其年龄的实用性。为了开始探测TRNA的生物作用，我们专注于专门用于蛋白质合成的tRNA，即引发剂trnamet（trnaimet）。我们生成了一组从四个不同基因组位置删除Trnairet副本的蝇突变体。我们的初步表型揭示了至少一个Trnaimet基因座有助于衰老，并指示了四个基因座的独特和冗余生物功能的相互作用。我们将使用这组突变体以及我们生成的一组记者线回答tRNA生物学中的基本问题，这将有助于我们了解衰老：为什么在整个动物的基因组中存在多个相同的tRNA基因副本？其次，我们将使用记者线来评估在发育过程中以及不同成人组织和器官中每个基因座的表达。我们将通过正式测试唯一的表达模式驱动独特的有机体功能来正式测试两组发现，并通过正式测试它们进行整合。第三，我们将研究Trnaimet基因座在衰老的可塑性中的作用。具体而言，我们将确定养分摄入量减少或TORC1抑制所产生的寿命是否部分是由Trnairaimet级别的变化引起的。该项目将回答TRNA生物学中的一个基本问题，以使我们在动物生理学背景下对TRNA的理解有所改变。它将为我们提供有关它们在动物衰老中的作用的开创性见解，以及破译Torc1下游的有机功能所需的知识。反过来，这些知识将为旨在确保在整个生活过程中确保人类健康的干预措施提供信息。