Mechanistic Studies on Sindbis Virus Replication

病毒复制是通过一系列大分子合成事件的精确协调来实现的。对于正链RNA病毒，基因表达和基因组复制的时间调控是通过病毒核糖核蛋白复合体(VRNP)的作用发生的。VRNP围绕病毒RNA组装，其组成由病毒和宿主蛋白质对特定RNA元件的募集确定。因此，在病毒复制周期的特定时间，蛋白质和病毒RNA元件的不同可获得性可以改变vRNP的组成并改变复合体的功能。如果我们要了解病毒复制所需的调控过程，识别特定大分子合成事件所需的RNA元件和结合它们形成vRNP的蛋白质是基本要求。本项目旨在了解使用甲病毒属的模式物种Sindbis病毒(SIN)对正链RNA病毒基因表达和基因组复制的调节。在SIN复制过程中，基因组被翻译，产生非结构多蛋白。这种蛋白质的半加工形式是复制(负链合成)该蛋白质的基因组所必需的。反过来，负链RNA作为生产后代基因组的模板，以及由包含完全加工的非结构蛋白的复合体合成的亚基因组mRNA。因此，很明显，不同的vRNP复合体执行这些过程中的每一个。该项目旨在阐明介导vRNP组成和功能转变的分子相互作用，这些研究将对理解甲型病毒复制所需的分子机制产生重大影响。此外，由于正链RNA病毒由一个共同的复制方案联合在一起，从这些研究中建立的原理将对所有正链RNA病毒的研究具有更广泛的兴趣和重要性。该项目将为本科生、研究生和博士后研究员的培训提供一个论坛。来自各种计划(包括最大化学生多样性计划和本科生研究体验计划)的一些学生已经参与了实验室的研究，并完全预计这种参与将继续下去。

Virus replication is achieved through the precise coordination of a series of macromolecular synthetic events. For plus-strand RNA viruses the temporal regulation of gene expression and genome replication occurs through the action of the viral ribonuclear protein complex (vRNP). The vRNP is assembled around viral RNA and its composition is defined by the recruitment of proteins, both viral and host, to specific RNA elements. Differential availability of proteins and viral RNA elements at particular times during the virus replication cycle can therefore alter the composition of the vRNP and change the function of the complex. Identifying RNA elements required for specific macromolecular synthetic events and the proteins that bind them to form a vRNP are fundamental requirements if we are to understand the regulatory processes necessary for virus replication.This project seeks to understand the regulation of gene expression and genome replication of plus-strand RNA viruses using Sindbis virus (SIN), the type species of the alphavirus genus. During SIN replication the genome is translated giving rise to the non-structural polyprotein. A semi-processed form of this protein is required for the copying (minus-strand synthesis) of the genome from which it was translated. In turn the minus-strand RNA serves as a template for production of progeny genomes, and a subgenomic mRNA synthesized by a complex containing the fully processed non-structural proteins. It is therefore apparent that different vRNP complexes perform each of these processes. The project aims to elucidate the molecular interactions that mediate the transitions in vRNP composition and function These studies will significantly impact the understanding of the molecular mechanisms required for alphavirus replication. Additionally, as plus-strand RNA viruses are united by a common scheme of replication, principles established from these studies will be of more general interest and importance for the study of all plus-strand RNA viruses. The project will provide a forum for the training of undergraduate students, graduate students, and post-doctoral fellows. A number of students from various programs (including Initiative for Maximizing Student Diversity Program and Research Experience for Undergraduates Program) have participated in research in the laboratory and it is fully expected that this participation will continue.