Key host factors co-opted to form viral replication organelles

具有RNA基因组的病毒给农业造成重大损失，并对人类健康构成重大风险。为了在宿主体内繁殖，这些病毒破坏宿主的蛋白质和细胞膜，建立大型病毒复制细胞器，在受感染的细胞中繁殖病毒。这些复杂的细胞器对复制至关重要，部分原因是保护病毒基因组免受宿主免疫系统的攻击。尽管这些病毒对农业和医学造成了昂贵的影响，但病毒复制细胞器的生物发生机制尚不完全清楚。本项目利用侵染植物的tombusviruses来解决病毒生命周期的这一关键组成部分。从这个项目中获得的见解包括抑制复制细胞器形成的新策略，从而提供了阻断病毒复制的方法，并促进了新型、有效和广泛的抗病毒方法的发展。该研究将促进跨学科培养研究生和博士后研究人员，包括植物病理学、生物化学和细胞生物学。该实验室还将为高中生提供动手研究的机会。番茄丛矮病毒是最先进的病毒系统之一，将用于揭示宿主因子在复制细胞器形成中的作用。许多病毒的新情况是，复制细胞器的形成对病毒复制至关重要。复制细胞器集中了病毒和宿主的成分，并对宿主的抗病毒反应提供保护。该领域的一个重大突破是鉴定了关键的增选宿主蛋白，即Sac1脂质磷酸酶、Fis1线粒体裂变蛋白和Atg11自噬支架蛋白是tombusvirus复制细胞器生物发生的关键宿主因子。这些增选的细胞蛋白与被劫持的细胞膜和病毒复制蛋白相互作用，并可能作为复制细胞器生物发生的关键组装平台。PI将根据酵母遗传学的强大力量，结合PI为tombusvirus开发的优雅的无细胞复制试验，确定它们的前病毒功能。类似的工作将扩展到tbsv -植物感染，这可能会为RNA病毒复制和病毒发病机制提供重要的新见解。基于阻断增选的Sac1、Fis1或Atg11的功能，开发一种有效的抗病毒策略可以在优雅的tombusvirus-yeast/plant系统中快速完成。抑制关键病毒复制细胞器的形成可能是阻断病毒复制的一种有效方法，因此提出的研究将促进新型、有效和广泛的抗病毒方法的发展。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Viruses with RNA genomes cause major losses in agriculture and pose significant risks to human health. To multiply in their hosts, these viruses subvert host proteins and cellular membranes to build large viral replication organelles that serve to propagate viruses in the infected cells. These intricate organelles are essential for replication, in part by protecting the viral genomes from attack by the host's immune system. Despite the costly agricultural and medical impact of these viruses, the biogenesis of viral replication organelles is incompletely understood. This project employs plant-infecting tombusviruses to address this key component of the viral life cycle. Insights gained from this project include novel strategies to inhibit the formation of the replication organelles, thereby providing methods to block virus replication and facilitate the development of novel, potent and broad-range antiviral approaches. The research will promote interdisciplinary training for graduate students and a postdoctoral researcher across fields that include plant pathology, biochemistry and cell biology. The lab will also provide hands-on research opportunities for high school students. Tomato bushy stunt virus, which is among the most advanced viral systems, will be used to unravel the roles of host factors in replication organelle formation. The emerging picture with many viruses is that the formation of replication organelles, which concentrate viral and host components and provide protection against antiviral responses by the host, absolutely critical for virus replication. A major breakthrough in this area by the PI is the identification of critical co-opted host proteins, namely Sac1 lipid phosphatase, Fis1 mitochondrial fission protein and Atg11 autophagy scaffold protein as key host factors in the biogenesis of tombusvirus replication organelles. These co-opted cellular proteins interact with each other, with the hijacked cellular membranes and with the viral replication proteins and likely serve as key assembly platforms for the biogenesis of replication organelles. The PI will identify their pro-viral functions based on the awesome power of yeast genetics in combination with elegant cell-free replication assays developed for tombusviruses by the PI. Similar work will be extended to TBSV-plant infections, which will likely lead to major new insights into RNA virus replication and viral pathogenesis. Developing an efficient antiviral strategy based on blocking the function of co-opted Sac1, Fis1 or Atg11 could rapidly be done in the elegant tombusvirus-yeast/plant systems. Inhibition of formation of critical viral replication organelles could be a powerful approach to block virus replication, thus the proposed research will facilitate the development of novel, potent and broad-range antiviral approaches.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.