tRNA modification reprogramming in artemisinin-resistant Plasmodium falciparum: An epigenetic driver of resistance?

项目总结/摘要：原理：青蒿素（ART）耐药疟原虫的传播 恶性疟原虫（Pf）菌株遍布亚洲，最近在非洲和南美洲出现， 治疗和控制疟疾ART耐药性主要由Pf K13的突变介导，这减少了药物治疗。 其通过减少血红蛋白内吞作用而激活，并且在峰值药物水平期间启动静止。我们 初步数据揭示了tRNA修饰、重编程和蛋白质组学变化在突变体中的作用， K13寄生虫暴露于ART压力。在这个指导性的职业项目中，我们假设沉默是 通过重编程tRNA修饰进行表观遗传调控，这利用密码子偏向性翻译来改变 寄生虫蛋白质组，并使ART处理的突变K13寄生虫的生存。标签：作为传染病 疾病医生与微生物学和免疫学博士学位，我独特的定位，以桥梁生物医学 研究和患者护理，以了解Pf在ART治疗中生存的分子机制。 在分子寄生虫学，质谱，蛋白质组学，RNA生物学和表观遗传学的进一步培训将 这对我成为一名独立的学术物理学家和科学家，专门研究压力反应至关重要 和耐药性。我有一个著名的导师在博士大卫菲多克和受益于一个杰出的多- 学科专家团队指导我的培训和科研进展。环境：Fidock实验室， 哥伦比亚大学欧文医学中心（CUIMC）一直是应用遗传学和多组学的先驱 探索Pf对ART和其他药物的耐药性的工具。这种丰富的环境还提供了访问 多个同基因k13编辑的Pf系和包括质谱专家在内的大型合作者网络- 基于tRNA修饰、蛋白质组学和密码子偏向翻译。CUIMC也有长期的跟踪记录， 使年轻的医生科学家能够在学术医学领域发展独立和成功的职业生涯。 方法：我们的中心假设是，tRNA修饰重编程，特别是s2 U修饰， 寄生虫如何通过改变其蛋白质组和调节进入和退出来实现ART抗性的核心 药物引起的静止在目标1中，我们将阐明在细胞中tRNA修饰重编程的动力学。 在一组K13变异体和遗传背景中的同基因ART耐药和ART敏感寄生虫。在 目的2，我们将应用条件性敲低方法来探索s2 U通路在ART耐药中的作用 和寄生虫的生存在目标3中，我们将测试互补假设，即氨基酰基上的修饰 tRNA调节ART介导的静止。该提案提供了一种创新的方法来研究K13如何 突变通过表观遗传变化实现ART抗性，表观遗传变化重新编程tRNA修饰， 对ART压力的翻译和蛋白质组学反应。如果实验证实，这些假设将成立 Pf如何调节其生物学以在药物介导的细胞应激中存活的新范例。我们的结果应该 还可以确定寄生虫的脆弱性，这些脆弱性可以用于治疗抗逆转录病毒疗法疟疾的新战略。

PROJECT SUMMARY / ABSTRACT: Rationale: The spread of artemisinin (ART)-resistant Plasmodium falciparum (Pf) strains across Asia and their recent emergence in Africa and South America imperils efforts to treat and control malaria. ART resistance is mediated primarily by mutations in Pf K13, which reduce drug activation by decreasing hemoglobin endocytosis and which initiate quiescence during peak drug levels. Our preliminary data have uncovered a role for tRNA modification reprogramming and proteomic changes in mutant K13 parasites exposed to ART pressure. In this mentored career project, we hypothesize that quiescence is epigenetically regulated by reprogramming tRNA modifications, which leverage codon-biased translation to alter the parasite proteome and enable the survival of ART-treated mutant K13 parasites. Candidate: As an Infectious Diseases physician with a PhD in Microbiology and Immunology, I am uniquely positioned to bridge biomedical research and patient care to understand the molecular mechanisms that Pf employs to survive ART treatment. Further training in molecular parasitology, mass spectrometry, proteomics, RNA biology, and epigenetics will be crucial for my development into an independent academic physician-scientist specializing in Pf stress responses and drug resistance. I have a renowned mentor in Dr. David Fidock and benefit from an outstanding multi- disciplinary team of experts to guide my training and research progress. Environment: The Fidock laboratory at the Columbia University Irving Medical Center (CUIMC) has been a pioneer in applying genetic and multi-omic tools to explore Pf resistance to ART and other drugs. This enriching environment also provides access to multiple isogenic k13-edited Pf lines and a large network of collaborators including experts in mass spectrometry- based tRNA modifications, proteomics, and codon-biased translation. CUIMC also has a long track record of enabling young physician-scientists to develop independent and successful careers in academic medicine. Approach: Our central hypothesis is that tRNA modification reprogramming, specifically the s2U modification, is central to how parasites achieve ART resistance by altering their proteome and regulating entry into and exit from drug-induced quiescence. In Aim 1, we will elucidate the kinetics of tRNA modification reprogramming in isogenic ART-resistant and ART-sensitive parasites across a panel of K13 variants and genetic backgrounds. In Aim 2, we will apply conditional knockdown approaches to explore the role of the s2U pathway in ART resistance and parasite survival. In Aim 3, we will test the complementary hypothesis that modifications on the amino-acyl tRNA regulate ART-mediated quiescence. This proposal provides an innovative approach to examining how K13 mutations achieve ART resistance via epigenetic changes that reprogram tRNA modifications to alter translational and proteomic responses to ART pressure. If confirmed experimentally, these hypotheses will set a new paradigm for how Pf can modulate its biology to survive drug-mediated cellular stress. Our results should also identify parasite vulnerabilities that can be leveraged into new strategies to treat ART-resistant malaria.