Role of a novel human-virus chimeric protein generated by upstream translation and genetic overprinting

摘要 病原体跨越宿主屏障并建立感染的能力取决于 病原体衍生蛋白的表达。要了解病原体如何对抗寄主 并确定感染，我们需要清楚地了解病原体是什么蛋白质 编码，它们如何发挥作用，以及它们以什么方式对毒力做出贡献。海流 关于许多威胁生命的病原体的教义是它们只编码少数几种蛋白质 因为它们有限的基因组。RNA病毒，如甲型流感病毒(IAV)，就是一个很好的例子 这一范例。基于此，我们对病毒生命周期、发病机制和 疾病控制的治疗或预防方法仅限于一小部分已知的 病毒基因组编码的蛋白质。 我们假设，由于宿主和病毒的遗传相互作用，RNA病毒可以产生 在感染过程中转化为蛋白质的嵌合宿主病毒基因。事实上，IAV，还有 许多其他高致病性病毒，使用短宿主RNA来启动病毒转录 产生病毒核糖核酸。因此，我们进一步假设了宿主引物中的起始密码子 序列可以驱动嵌合的人类病毒编码序列的表达，这一过程 将取决于病毒非编码区序列的可译性。我们最近的出版物指出 这种机制的存在，产生了人类病毒蛋白嵌合体，或者是 通过基因叠印对典型病毒蛋白或新型多肽进行延伸。这个想法是 在一些初步案例研究中得到进化分析和功能数据的支持。这个 这一探索性R21应用的目标是详细描述 允许产生病毒-人类蛋白，并在生理上 一种由IAV产生的保守的人类病毒蛋白的作用。一种组合 保留遗传方法将被用来产生病毒突变体，并充分表征它们的 在细胞和组织水平上的毒力。通过调查未知病原体的作用- 衍生蛋白，这一提议有可能确定它们的重要性，阐明它们的作用 并为未来的病毒学-免疫学-和 基因组学研究旨在确定宿主病毒蛋白在多种病毒中的可能存在 产生(3个病毒家族，包括人类、其他动物和植物病毒)。

SUMMARY The capacity of a pathogen to overcome host barriers and establish infection is based on the expression of pathogen-derived proteins. To understand how a pathogen antagonizes the host and establishes infection, we need to have a clear understanding of what proteins a pathogen encodes, how they function, and in what manner they contribute to virulence. The current dogma about many life-threatening pathogens is that they encode just a handful of proteins because of their limited genome. RNA viruses, like Influenza A virus (IAV), are a prime example of this paradigm. Based on this, our understanding of virus life cycles, pathogenesis, and therapeutic or prophylactic methods of disease containment are limited to a small set of known proteins encoded by the viral genome. We hypothesized that, as a result of host-virus genetic interaction, RNA viruses could generate chimeric host-virus genes that are translated into proteins during infection. In fact, IAV, and many other highly pathogenic viruses, use short host RNAs to prime viral transcription to generate viral mRNA. Thus, we further hypothesized that start codons within host primer sequences could drive the expression of chimeric human-viral coding sequences, a process that would depend on the translatability of the viral UTR sequences. Our recent publication indicates the existence of this mechanism, which creates human-virus protein chimeras either as extensions of canonical viral proteins or novel polypeptides by genetic overprinting. This idea is supported by evolutionary analysis and functional data in a few preliminary case studies. The goal of this exploratory R21 application is to characterize in detail the genomic context that allows the generation of viral-human proteins along with characterizing, in a physiological manner, the role of a conserved human-virus protein generated by IAV. A combination of reserve genetic approaches will be used to generate viral mutants and to fully characterize their virulence at the cellular and organismal level. By investigating the role of unknown pathogen- derived proteins, this proposal has the potential to establish their importance, elucidate their role during infection, and provide a proof-of-principle study for future virology- immunology- and genomic studies aimed at defining host-virus proteins in the multiple virus in which they can be generated (3 viral families comprising human, other animal and plant viruses).