RNA-dependent RNA Polymerase

RNA依赖性RNA聚合酶

• 批准号: 10017543
• 负责人: CRAIG E. CAMERON
• 金额: $ 31.18万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-01 至 2021-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10017543
• 关键词: RNA; dependent; Polymerase

 DESCRIPTION (provided by applicant): Using poliovirus (PV) and its RNA-dependent RNA polymerase (RdRp), 3Dpol, as our primary model system, we, our collaborators and other picorna virologists have made a very compelling case for RdRp fidelity and the corresponding genetic diversity of the viral population as contributors to viral pathogenesis and virulence. This relationship between viral genetic diversity and viral fitness established using the PV model has now been demonstrated for a variety of virus families. In addition, we have demonstrated that the rate of nucleotide addition can be tuned and contributes to viral genetic diversity and viral fitness. Therefore, the overarching hypothesis driving our studies is that mechanisms governing RdRp speed and fidelity can be targeted genetically and chemically for development of attenuated viruses and antiviral agents, respectively. If one is to harness the full therapeutic an prophylactic potential of modulated RdRp function, however, knowledge of the physical mechanism(s) controlling RdRp speed and fidelity is needed. One goal of this application is to test and to exploit a new model for nucleotide selection that we anticipate can be applied to any RdRp. Recombination is a major contributor to viral evolution, leading to the emergence of vaccine-resistant strains and expansion of virus host range. Unfortunately, we lack sufficient knowledge of the molecular mechanism of RNA virus recombination to prevent this process from thwarting vaccine development and long- term efficacy. Therefore, an understanding of recombination is of potentially broad, practical value. For example, detailed knowledge of the mechanism of recombination may establish principles that can be exploited for development of strategies to suppress recombination and/or design of recombination-deficient vaccine strains. A second goal of this application is to create fundamental knowledge on the mechanism of RNA virus recombination using the PV model. During the next funding period, our central objectives will be: (1) Identify active-site determinants of RdRp incorporation fidelity that can be targeted for viral attenuation; (2) Exploit the promiscuity of the RdRp nascent base pair-binding pocket for antiviral therapy; (3) Elucidate a mechanism for template switching/strand transfer by PV RdRp and establish its relevance to RNA recombination by PV in cells. The proposed studies will create important knowledge that should contribute to development of strategies to treat and to prevent RNA viral infections, including those of current concern: Ebola virus, enterovirus D68, and Middle Eastern respiratory syndrome coronavirus.

 描述（由申请人提供）：使用脊髓灰质炎病毒（PV）及其RNA依赖性RNA聚合酶（RdRp）3Dpol作为我们的主要模型系统，我们、我们的合作者和其他小RNA病毒学家已经提出了一个非常令人信服的案例，证明RdRp保真度和病毒群体的相应遗传多样性是病毒发病机制和毒力的贡献者。这 使用PV模型建立的病毒遗传多样性和病毒适应性之间的关系现已在多种病毒家族中得到证明。此外，我们还证明了核苷酸添加速率可以调整，并有助于病毒遗传多样性和病毒适应性。因此，推动我们研究的首要假设是，控制 RdRp 速度和保真度的机制可以分别通过基因和化学手段来开发减毒病毒和抗病毒药物。然而，如果要充分利用调节 RdRp 功能的治疗和预防潜力，则需要了解控制 RdRp 速度和保真度的物理机制。该应用程序的一个目标是测试和开发一种新的核苷酸选择模型，我们预计该模型可以应用于任何 RdRp。重组是病毒进化的主要因素，导致疫苗抗性株的出现和病毒宿主范围的扩大。不幸的是，我们对 RNA 病毒重组的分子机制缺乏足够的了解，无法阻止这一过程阻碍疫苗的开发和长期功效。因此，对重组的理解具有潜在广泛的实用价值。例如，对重组机制的详细了解可以建立可用于开发抑制重组的策略和/或设计重组缺陷疫苗株的原理。该应用程序的第二个目标是使用 PV 模型创建有关 RNA 病毒重组机制的基础知识。在下一个资助期间，我们的中心目标将是：（1）确定 RdRp 掺入保真度的活性位点决定因素，可作为病毒减毒的目标； (2) 利用RdRp新生碱基对结合口袋的混杂性进行抗病毒治疗； (3) 阐明 PV RdRp 进行模板转换/链转移的机制，并确定其与细胞中 PV 进行的 RNA 重组的相关性。拟议的研究将创造重要的知识，有助于制定治疗和预防 RNA 病毒感染的策略，包括当前关注的病毒感染：埃博拉病毒、肠道病毒 D68 和中东呼吸综合征冠状病毒。