Structure and dynamics of RNA elements regulating viral aberrant RNA synthesis

摘要 季节性流感病毒每年导致6亿例病例和数千亿美元 在亏损中。大流行和禽流感病毒构成了更大的威胁，因为它们可以 失调我们的免疫反应和/或扩散到多个器官并关闭。当前 有证据表明，异常的病毒复制导致了先天的失调。 免疫反应与低致病性高致病性菌株的产生 先驱物。 从低致病性病毒到高致病性病毒的转变需要插入多个碱性氨基酸。 病毒血凝素(HA)表面蛋白裂解部位的酸。在鸟类中，这种变化 HA允许病毒在系统内传播，导致家禽死亡率高达100%。 氨基酸插入裂解位点的分子机制还不是很清楚。 可以理解，但它可能涉及HA基因中RNA聚合酶的卡顿，导致 核苷酸插入。 病毒RNA聚合酶还可以从病毒基因组中删除核苷酸，导致病毒基因组变短 异常的RNA。最近的研究表明，大流行和禽流感病毒感染 产生长度约为56-125个核苷酸的RNA分子，称为迷你病毒RNA， 它们的合成与疾病标志物的上调有关。RNA聚合酶是如何 在病毒基因组中进行如此大的缺失尚不清楚。 该项目将使用一种新的方法在病毒的关键步骤中阻止病毒RNA聚合酶 复制和异常RNA合成，并使用最先进的生化、生物物理和 揭示病毒复制和基因组封装步骤的结构化方法 作为异常的RNA合成。这样做，这个项目将有助于一个完整的机械化 了解流感复制并回答长期存在的基本问题 高致病性流感病毒的出现。

SUMMARY Seasonal influenza viruses cause >600 million cases annually and hundreds of billions of dollars in losses. Pandemic and avian influenza viruses present an even greater threat because they can dysregulate our immune response and/or spread to and shut down multiple organs. Current evidence suggests that aberrant viral replication contributes to a dysregulating of the innate immune response and the emergence of highly pathogenic strains from low pathogenic precursors. The transition from a low to highly pathogenic virus involves insertion of multiple basic amino acids in the cleavage site of the viral hemagglutinin (HA) surface protein. In birds, this change in HA allows the virus to spread systemically, resulting in mortality rates of up to 100% in poultry. The molecular mechanism underlying insertion of amino acids in the cleavage site is not well understood, but it may involve stuttering of the RNA polymerase in the HA gene, resulting in nucleotide insertions. The viral RNA polymerase can also delete nucleotides from the viral genome, resulting in shorter aberrant RNAs. Recent studies have shown that pandemic and avian influenza A virus infections produce RNA molecules of about 56-125 nucleotides in length, called mini viral RNAs, and that their synthesis is correlated with the upregulation of disease markers. How the RNA polymerase makes such large deletions in the viral genome is not known. This project will use a novel method to stall the viral RNA polymerase during key steps of viral replication and aberrant RNA synthesis, and use state-of-the-art biochemical, biophysical, and structural approaches to reveal the steps of viral replication and genome encapsidation, as well as aberrant RNA synthesis. In doing so, this project will contribute to a complete mechanistic understanding of influenza replication and answer long-standing, fundamental questions about the emergence of highly pathogenic influenza viruses.