Understanding the evolution and function of xenobiotic detoxification enzymes in a global crop pest

了解全球农作物害虫中外源解毒酶的进化和功能

• 批准号: BB/X010058/1
• 负责人: Bartlomiej Troczka
• 金额: $ 50.28万
• 依托单位: UNIVERSITY OF EXETER
• 依托单位国家: 英国
• 项目类别: Fellowship
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FX010058%2F1
• 关键词: Understanding; evolution; function; xenobiotic; detoxification

Detoxification enzymes play an important role in the ability of insects to neutralise threats caused by foreign chemicals (xenobiotics), such as plant secondary metabolites and synthetic pesticides. Indeed, insect pests, such as the aphid Myzus persicae, frequently adapt to novel host plants or develop resistance to synthetic insecticides via quantitative or qualitative changes in these enzymes. One of the most important superfamilies of enzymes involved in the evolution of insect resistance to plant-derived and human-made toxins are cytochrome P450s (or CYPs). M. persicae has over 60 individual genes encoding P450 enzymes (the CYPome), however, only a handful of these have been functionally characterised to date. This is a reflection of the time and effort required to produce functional protein for analysis in the lab. As a consequence, while we have a good understanding of the type and number of P450 genes in insects we know very little about what they actually do. In the context of pest species, key questions remain on which P450s have the capacity to detoxify insecticides, the extent to which genetic variation in these P450s in insect populations can influence insecticide metabolism and which of the building blocks (amino acids) that make up P450 proteins are particularly important in interacting with insecticides and breaking them down (structure-function determinants). In this project I aim to exploit a unique set of genomic resources recently created for M. persicae, in combination with recent advances in synthetic biology and modelling of protein structure, to understand how global diversity in an entire gene superfamily impacts the ability of M. persicae to adapt to natural and synthetic xenobiotics.In the first objective of the project, I will investigate where and when all the individual P450s in M. persicae are present through the insect body and life cycle in order to gain insight into their potential function. I will then use state of the art modelling tools to create 3D structures of each protein to gain an intimate understanding of how they interact with small molecules such as toxins and predict which P450s break down insecticides. These computational predictions will be tested in the laboratory utilizing recent advances in protein production to individually express the entire complement of P450 enzymes in M. persicae and examine their ability to metabolise insecticides and other model substrates using biochemical approaches. This will provide the first ever functional dataset on the complete suite of P450s in an insect, and unprecedented insights into the biological function of each member of the CYPome including those that are key actors in xenobiotic metabolism.In the second objective of the project, I will leverage a global sample of >110 re-sequenced clones of M. persicae, in combination with 3D modelling and functional expression to understand the potential for standing genetic variation in CYP genes in aphid populations to be co-opted in the evolution of resistance. The data obtained from these analyses, together with that derived from Objective 1, will allow me to identify key structure-function determinants of P450-mediated insecticide metabolism. The results obtained from the first two objectives of this project will provide fundamental insights into the evolution and function of an important group of enzymes that are found in all kingdoms of life, however, they also have the potential for significant applied impact. To realise this impact I will translate the knowledge gained into a set of molecular tools that can be used to rapidly screen compounds against aphid pest P450s and so identify resistance-breaking chemistry. In summary, the knowledge and tools generated in this study will provide i) a holistic understanding of the function and diversity of the insect CYPome and its relevance for the evolution of insecticide resistance; ii) a toolkit to study and combat P450-mediated resistance.

解毒酶在昆虫中和外国化学物质（异生物生物）（例如植物二次代谢产物和合成农药）中中和威胁的能力中起着重要作用。实际上，虫害（例如蚜虫myzus persicae）经常通过这些酶的定量或定性变化来适应新型宿主植物或对合成杀虫剂产生抗性。涉及昆虫对植物来源和人为毒素的抗药性的酶的最重要的超家族之一是细胞色素P450（或CYPS）。 M. persicae具有编码P450酶（CYPOME）的60多个单独的基因，但是，迄今为止，其中只有少数在功能上表征了其中的少数。这是产生功能蛋白进行分析所需的时间和精力的反映。结果，尽管我们对昆虫中P450基因的类型和数量有很好的了解，但我们对它们的实际工作知之甚少。在害虫物种的背景下，P450具有对杀虫剂排毒的能力仍然存在的关键问题，昆虫种群中这些P450的遗传变异的程度可以影响杀虫剂的代谢以及哪些构建块（氨基酸）构成P450蛋白质在与杀虫剂相互作用以及与杀虫剂相互作用（结构效果）（结构效果（结构）的确定性（结构））。在这个项目中，我旨在利用最近为Persicae创建的独特基因组资源，结合最新的合成生物学和蛋白质结构的建模的进步，以了解整个基因超级家族中的全球多样性如何影响Persicae M. persicae的能力，可以通过PROPPORD和个人PROPS extrye and M. extry and M. extry and M. nys Provection and In M. In M.生命周期以深入了解其潜在功能。然后，我将使用最先进的建模工具来创建每种蛋白质的3D结构，以深入了解它们如何与小分子（例如毒素）相互作用，并预测哪些P450分解了杀虫剂。这些计算预测将在实验室中测试，利用蛋白质生产的最新进展，以单独表达persicae中P450酶的全部补体，并检查其使用生物化学方法来代谢杀虫剂和其他模型底物的能力。这将为昆虫的完整P450套件提供有史以来的第一个功能数据集，并且是对每个CYPOME的生物学功能的前所未有的见解，包括那些是在异种生物代谢中的关键参与者的生物学功能。蚜虫种群中CYP基因的变化将在抗性的演化中采用。从这些分析获得的数据以及从目标1中得出的数据将使我能够鉴定P450介导的杀虫剂代谢的关键结构功能决定因素。从该项目的前两个目标获得的结果将提供有关在所有生活王国中发现的重要酶的演变和功能的基本见解，但是，它们也有可能产生重大应用影响。为了实现这种影响，我将把获得的知识转化为一组分子工具，这些工具可用于快速筛选针对蚜虫害虫P450的化合物，从而识别抗抗性的化学反应。总而言之，这项研究中产生的知识和工具将为i）对昆虫cypome的功能和多样性的整体理解及其与杀虫剂耐药性进化的相关性； ii）一种用于研究和打击P450介导的电阻的工具包。