Proteomics of Venezuelan Equine Encephalitis Virus nsP3 protein

摘要 委内瑞拉马脑炎病毒（VEEV）是一种归类为B类选择因子的甲病毒 和一种新出现的传染源目前没有FDA批准的治疗方法或疫苗可用于 治疗VEEV感染。我们在过去两年的研究发现，宿主激酶发挥了重要作用， 在VEEV感染的细胞中建立生产性感染中起重要作用。抑制宿主激酶 通过小分子抑制剂的活性降低病毒载量并改善体外和体内宿主存活。我们 已经确定病毒蛋白nsP 3与宿主激酶（IKK激酶）相互作用，这促使我们考虑 感染细胞中nsP 3的磷酸化状态。我们的分析显示， nsP 3，其中许多对我们的小分子抑制剂治疗敏感。我们还确定， 在感染细胞中，除了IKK外，nsP 3还与DDX-1和DDX-3相互作用。未满足的需求是更好的 了解nsP 3上发生的磷酸化事件以及这些事件对 蛋白质：涉及nsP 3和宿主蛋白质的蛋白质相互作用。了解nsp 3的重要性 磷酸化对病毒增殖的抑制作用将为有效的治疗和合理的设计铺平道路。 疫苗。我们的假设是nsP 3将在感染细胞中的多个残基上磷酸化，并且至少 这些磷酸化事件中的一些对于病毒增殖是关键的。此外，磷酸化 nsP 3的状态将影响其与受感染细胞中的宿主蛋白相互作用的能力。因此，在这方面， 当靶磷酸化位点在病毒中发生突变时，病毒在体内的毒力将降低。 我们将通过以下具体目标来检验我们的假设： 目标1.感染细胞中nsP 3的磷酸化。 目标2. nsP 3与感染细胞中宿主蛋白的相互作用。

Abstract Venezuelan Equine Encephalitis Virus (VEEV) is an alphavirus that is classified as a category B select agent and an emerging infectious agent. There are no FDA approved therapeutics or vaccines currently available for treatment of VEEV infection. Our research over the past two years have uncovered that host kinases play an important role in the establishment of a productive infection in VEEV infected cells. Inhibition of host kinase activity by small molecule inhibitors decreases viral load and improves host survival in vitro and in vivo. We have identified that the viral protein nsP3 interacted with a host kinase (IKKwhich prompted us to consider the phosphorylation status of nsP3 in infected cells. Our analysis revealed multiple phosphorylated residues on nsP3, many of which were susceptible to our small molecule inhibitor treatment. We have also determined that in addition to IKK nsP3 interacted with DDX-1 and DDX-3 in infected cells. An unmet need is a better understanding of the phosphorylation events that occur on nsP3 and the impact of those events on the protein:protein interactions involving nsP3 and host proteins. Understanding the importance of nsP3 phosphorylation to viral multiplication will pave the way for effective therapeutics and rationally designed vaccines. Our hypothesis is that nsP3 will be phosphorylated on multiple residues in infected cells and at least some of these phosphorylation events will be critical to viral multiplication. In addition, the phosphorylation status of nsP3 will impact its ability to interact with the host proteins in the infected cell. As a consequence, when target phosphorylation sites are mutated in the virus, the virulence of the virus will be reduced in vivo. We will test our hypothesis with the following specific aims: Aim 1. Phosphorylation of nsP3 in infected cells. Aim 2. Interaction of nsP3 with host proteins in infected cells.