Picornavirus Molecular Biology

描述(由申请人提供)：这项拨款申请中建议的工作的目的是加强我们对脊髓灰质炎病毒(PV)--一种属于短小航行科的肠道病毒--包裹其基因组的机制的了解。这一病毒家族包括大量的人类和动物病原体，每年在全球范围内造成60多亿人感染。这些感染导致各种疾病，从轻微的(普通感冒)到严重的(小儿麻痹症)。尽管进行了多年的研究，但光伏发电生命周期中大多数步骤的细节仍不清楚。然而，光伏病毒的扩散仍然是一个重要的医学问题，因为即使在全球范围内光伏病毒的传播中断后，预计也会发生流行性光伏病毒感染。这项建议可以分为三个部分。第一个目标是开发新的遗传工具来研究由PV和密切相关的C簇柯萨奇A病毒构建的嵌合体的囊化遗传学。我们期望嵌合病毒的形态发生表型将在分析衣壳和非结构蛋白在囊化过程中的相互作用方面非常有用。该提案的第二个目的涉及两种特定的肠道病毒包囊抑制剂，即海因和L-丁硫宁-亚磺胺，它们的作用预计会在不同阶段阻断包囊。在这项研究中，将使用PV、CAVs和PV/C-CAV嵌合体来鉴定和分析参与囊化的蛋白质中的逃逸突变。在我们的第三个目标中，我们建议分析非结构蛋白2CATPase、3CDpro、VPG和在形态发生中的作用，并寻找难以捉摸的RNA封装信号。我们计划使用遗传学和生物化学研究来分析非结构蛋白2CATPase和3CDpro在囊化过程中的作用。VPG的作用将通过对数百个VPG突变体的大规模扫描来测试，目的是找到复制阳性但包膜阴性的突变体。最后，我们将使用一种新的策略(密码子对优化)来扫描PV RNA以寻找难以捉摸的封装信号。由于包囊是一个独特的病毒过程，了解其机制将有助于针对肠道病毒生命周期中这一特定步骤的抗病毒药物的开发。2CATPase和3CDPro蛋白在肠道病毒中高度保守，为治疗多种肠道病毒病提供了良好的药物开发靶点。相信这些研究和结果不仅对研究其他肠道病毒包膜的研究人员感兴趣，而且对小核糖核酸病毒或一般RNA病毒感兴趣的人也会感兴趣。

DESCRIPTION (provided by applicant): It is the objective of the work proposed in this grant application to enhance our understanding of the mechanisms by which poliovirus (PV), an enterovirus belonging to the Picornaviridae, encapsidates its genome. This virus family includes a large number of human and animal pathogens that cause more than 6 billion human infections worldwide each year. These infections lead to a variety of diseases ranging from the mild (common cold) to the serious (poliomyelitis). In spite of research for many years the details of most steps in the life cycle of PV remain unknown. However, the proliferation of PV remains an important medical issue because epidemic PV infections are expected to occur even after the circulation of wt PV is interrupted globally. This proposal can be divided into 3 parts. The first aim deals with the development of new genetic tools to study the genetics of encapsidation of chimeras constructed from PV and the closely related C-cluster coxsackie A viruses. We expect that the morphogenesis phenotypes of the chimeric viruses will be very useful in analyzing the interaction of capsid and nonstructural proteins during encapsidation. The second aim of the proposal deals with two specific inhibitors of enterovirus encapsidation, hydantoin and L-buthionine-sulfoximine (BSO), whose effect is expected to block encapsidation at different stages. In this study PV, CAVs and PV/C-CAV chimeras will be used to identify and analyze escape mutants in proteins involved in encapsidation. In our third aim we propose to analyze the role in morphogenesis of non-structural proteins 2CATPase, 3CDpro, VPg, and, and search for an elusive RNA encapsidation signal. We plan to use both genetic and biochemical studies to analyze the role of nonstructural proteins 2CATPase and 3CDpro in encapsidation. The role of VPg will be tested by a large-scale scan of hundreds of VPg mutants with the aim of finding replication positive but encapsidation negative mutants. Finally, we will use a novel strategy (codon-pair optimization) to scan the PV RNA for an elusive encapsidation signal. Since encapsidation is a uniquely viral process an understanding of its mechanism will aid the development of antiviral drugs that target this particular step in the enteroviral life cycle. The 2CATPase and 3CDpro proteins are highly conserved among enteroviruses hence they provide an excellent target for drug development to treat multiple enteroviral diseases. It is believed that these studies and results will be of interest not only to those investigators who study the encapsidation of other enteroviruses but also to those who are interested in picornaviruses or RNA viruses in general.