Essential early events in the flavivirus lifecycle

项目摘要 节肢动物传播的黄病毒，如登革热病毒、西尼罗河病毒、黄热病病毒（YFV）和寨卡病毒 病毒是人类疾病的主要原因。我们正在研究早期，融合后和复制前 事件的黄病毒的生命周期，通过使用原型黄病毒，YFV，作为我们的模型。我们的总体 一种假说是，在脊椎动物和无脊椎动物宿主中交替复制的黄病毒， 进化到使用i）宿主之间共享的高度保守因子;和ii）多个冗余因子 在宿主之间可能没有很好地保存。因此，YFV的发现将是 通过与其他黄病毒以及人类和蚊子细胞之间的比较进行验证和研究。 目的1着重于融合后的核衣壳脱壳过程， 哪些细胞能解开这致命的货物目标1是我们初步数据的逻辑延伸，表明 可翻译的YFV基因组的递送需要细胞泛素化和VCP/p97，一种细胞泛素化酶， 从大分子复合物中提取泛素化蛋白质的ATP酶。目标2侧重于 鉴定切割病毒NS 1 -2A多蛋白中间体的细胞蛋白酶。裂解 黄病毒复制所必需的蛋白酶（如图所示），但这种蛋白酶的身份仍然难以捉摸 二十多年了我们已经鉴定了一个相关候选NS 1 -2A蛋白酶的小家族， 正在通过严格的组合基因切除来验证它们的活性。这些努力将解决长期- 黄病毒基因表达和复制的长期难题，并确定未来的目标 开发广泛作用的抗病毒药物。

Project Summary Arthropod-borne flaviviruses such as dengue virus, West Nile virus, yellow fever virus (YFV), and Zika virus, are a major cause of human disease. We are studying the early, post-fusion and pre-replication events in the flavivirus lifecycle by using the prototype flavivirus, YFV, as our model. Our overarching hypothesis is that flaviviruses, which alternately replicate in vertebrate and invertebrate hosts, have evolved to use i) highly conserved factors shared between hosts; and ii) multiple, redundant factors that may not be well conserved between hosts. Therefore, discoveries made with YFV will be validated and studied by comparison to other flaviviruses and between human and mosquito cells. Aim 1 focuses on the post-fusion process of nucleocapsid uncoating, dissecting the mechanisms by which cells unlock this fateful cargo. Aim 1 is a logical extension of our Preliminary Data showing that the delivery of a translatable YFV genome requires cellular ubiquitylation and VCP/p97, a cellular ATPase that extracts ubiquitylated proteins from large macromolecular complexes. Aim 2 focuses on identifying the cellular protease(s) that cleave the viral NS1-2A polyprotein intermediate. Cleavage is essential for flavivirus replication (shown here), yet the identity of this protease has remained elusive for over two decades. We have identified a small family of related candidate NS1-2A proteases and are validating their activity by rigorous, combinatorial genetic ablation. These efforts will solve long- standing puzzles in flavivirus gene expression and replication and identify targets for future development of broadly acting antivirals.