Power naps: ribosome hibernation in bacterial drug targeting and stress tolerance

小睡：细菌药物靶向和应激耐受中的核糖体冬眠

• 批准号: 2882641
• 金额: --
• 依托单位: Newcastle University
• 依托单位国家: 英国
• 项目类别: Studentship
• 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=studentship-2882641
• 关键词: Power; naps; ribosome; hibernation; bacterial

When bacteria are assaulted with drugs, they activate various defence mechanisms to stay alive and mitigate drug toxicity. These defence strategies allow pathogenic bacteria to escape clinical treatment, making drug-resistant infections a leading cause of death around the world. In this project, we will help address the emerging problem of antimicrobial resistance by describing a previously unknown mechanism of resistance known as "Balon-induced ribosome hibernation". In brief, our preliminary studies have identified a new bacterial protein, Balon, that induces a cellular "coma" when bacteria are treated with drugs: during a drug exposure, Balon binds most cellular ribosomes (machines of protein synthesis required for bacterial growth) and converts them into a dormant state, causing arrest of cell growth. When drugs are removed from the media, Balon "awakens" bacterial cells by forcing their ribosomes to reengage in protein synthesis. What's more, our preliminary study shows that Balon is encoded not only by many bacterial genomes but also by plasmids that confer multidrug-resistance in more than 150 clinical and veterinary isolates of pathogenic bacteria, including Salmonella enterica, Pseudomonas aeruginosa, Klebsiella pneumoniae and Escherichia coli.In this study, the successful student will explore the molecular mechanism of Balon-induced drug resistance. Aim 1 | Determine the cryo-EM structure of Balon bound to bacterial ribosomesFirst, using our established expertise in cryo-EM microscopy (Advisor 1), we will determine the structure of Balon bound to bacterial ribosomes. This structure will reveal the molecular mechanism by which Balon protects ribosomes from antimicrobial drugs (specifically from clinical drugs from aminoglycoside and macrolide families).Aim 2 | Determine the occurrence of Balon-coding genes in bacteria and their plasmidsNext, using our established expertise in studying the evolution of genomes and plasmids (Advisor 2), we will reveal the distribution of Balon-coding genes across all bacteria and bacterial plasmids with determined genome sequences. This analysis will help to better understand how this drug-resistance factor propagates among bacteria, including pathogens of humans and domesticated animals. Aim 3 | Determine the physiological conditions that stimulate Balon synthesis in bacterial cellsFinally, using our established expertise in transcriptional studies (Advisor 3), the student will clone promoters of Balon-coding genes into DNA reporters. These reporters will allow us test how hostile environments (such as antibiotics and numerous stress conditions) regulate the expression of Balon. This analysis will help us to test our hypothesis that certain environments predispose bacteria to higher or lower levels of drug resistance.

当细菌受到药物攻击时，它们会激活各种防御机制以维持生命并减轻药物毒性。这些防御策略使致病菌逃避临床治疗，使耐药感染成为世界各地死亡的主要原因。在这个项目中，我们将通过描述一种以前未知的被称为“balon诱导的核糖体冬眠”的耐药机制来帮助解决新出现的抗微生物药物耐药性问题。简而言之，我们的初步研究已经确定了一种新的细菌蛋白Balon，当细菌接受药物治疗时，它会诱导细胞“昏迷”：在药物暴露期间，Balon结合大多数细胞核糖体（细菌生长所需的蛋白质合成机器）并将其转化为休眠状态，导致细胞生长停滞。当药物从培养基中移除时，Balon通过迫使核糖体重新参与蛋白质合成来“唤醒”细菌细胞。此外，我们的初步研究表明，Balon不仅被许多细菌基因组编码，而且还被质粒编码，这些质粒使150多种临床和兽医分离的致病菌具有多重耐药性，包括肠沙门氏菌、铜绿假单胞菌、肺炎克雷伯菌和大肠杆菌。在本研究中，成功的学生将探索balon诱导的耐药的分子机制。目的1：确定细菌核糖体结合Balon的低温电镜结构首先，利用我们在低温电镜（Advisor 1）方面的专业知识，我们将确定与细菌核糖体结合的Balon的结构。该结构将揭示Balon保护核糖体免受抗菌药物（特别是氨基糖苷类和大环内酯类临床药物）侵害的分子机制。目标2 |确定细菌及其质粒中balon编码基因的发生接下来，利用我们在研究基因组和质粒进化方面的专业知识（顾问2），我们将揭示具有确定基因组序列的所有细菌和细菌质粒中balon编码基因的分布。这一分析将有助于更好地了解这种耐药因子是如何在细菌中传播的，包括人类和家养动物的病原体。目标3 |确定刺激细菌细胞中Balon合成的生理条件最后，利用我们在转录研究方面的专业知识（指导教师3），学生将把Balon编码基因的启动子克隆成DNA报告子。这些记者将允许我们测试恶劣环境（如抗生素和许多应激条件）如何调节Balon的表达。这一分析将帮助我们验证我们的假设，即某些环境会使细菌产生或高或低的耐药性。