Small RNA-mediated warfare between viruses and their hosts

项目摘要 非编码RNA（ncRNA）构成了人类细胞内存在的大部分RNA，并且是有效的 细胞过程的调节因子，包括翻译、剪接和转录后信使RNA（mRNA） 控制像人类一样，病毒产生ncRNA，其功能在很大程度上仍然未知。鉴于病毒 进化以最大化其小基因组中包含的信息，所有病毒ncRNA都被假定为 不降低我们的实验室研究了小病毒ncRNA调节宿主和病毒的机制。 这些过程的知识将有助于开发新的方法来治疗人类 疾病在接下来的五年里，我们将阐明两种不同的病毒ncRNAs的作用：小核 由致癌性g-疱疹病毒表达的RNA（snRNA）（项目1）和由致癌性g-疱疹病毒产生的微小RNA（miRNA）（项目2）。 SARS-CoV-2，一种引起急性呼吸道疾病的病毒（项目2）。 g-疱疹病毒是DNA病毒，其在潜伏期期间诱导宿主细胞转化和肿瘤发生。 潜伏病毒基因产生几种蛋白质和多种ncRNA。在其潜伏期， 典型的g-疱疹病毒，表达七种snRNA，称为HSUR。与人类snRNAs不同，HSUR 与mRNA剪接有关，但与调节细胞质中宿主RNA水平有关。有趣的是，我们的研究结果 表明HSUR主要定位于细胞核，其作用尚不清楚。另外我们 观察到HSUR选择性地将宿主细胞质RNA结合蛋白转运到细胞核中。在 项目1，我们将研究病毒snRNAs在细胞核中的作用，以探索病毒snRNAs在宿主细胞中的未知功能。 RNA结合蛋白，并获得深入了解g-疱疹病毒转化。 SARS-CoV-2是一种大型RNA病毒，是2019年冠状病毒病的病原体和来源 当前的流行病。我们和其他人最近发现了一种由SARS-CoV-2表达的miRNA，命名为 CoV-miR-07 a，其下调阿利亚涉及干扰素信号传导的宿主基因。我们的初步数据 显示CoV-miR-O 7a大量存在于SARS-CoV-2病毒粒子内。我们假设CoV-miR-O 7a (and可能还有其他ncRNA）被选择性地掺入病毒体中，以允许宿主基因的早期操作 表情在项目2中，我们将研究病毒miRNA掺入的机制和意义 以了解SARS-CoV-2发病机制的未知方面， 描述了病毒抑制宿主抗病毒反应的以前未探索的方式。 我们的多学科方法，结合MIRA资金的灵活性，将导致 建立了一个独特的研究计划，围绕小RNA生物学的理解， 病毒感染。在阐明小病毒ncRNA的功能方面，这项研究将推动RNA生物学领域的发展 和病毒学这些知识可以导致识别用于治疗病毒性疾病的新靶点，包括 病毒诱发的癌症

PROJECT SUMMARY Non-coding RNAs (ncRNAs) constitute the majority of RNAs present within the human cell, and are potent regulators of cellular processes, including translation, splicing, and post-transcriptional messenger RNA (mRNA) control. Like humans, viruses produce ncRNAs, whose functions are still largely unknown. Given that viruses evolved to maximize the information contained within their small genomes, all viral ncRNAs are postulated to be functional. Our lab studies the mechanisms by which small viral ncRNAs modulate host and viral processes, the knowledge of which will contribute to the development of new approaches to treat human disease. In the next five years, we will elucidate the roles of two distinct viral ncRNAs classes: small nuclear RNAs (snRNAs) expressed by an oncogenic g-herpesvirus (Project 1), and a microRNA (miRNA) produced by SARS-CoV-2, a virus that causes acute respiratory disease (Project 2). g-herpesviruses are DNA viruses, which during latency induce host cell transformation and oncogenesis. The latent viral genes produce several proteins and multiple ncRNAs. During its latency, herpesvirus saimiri, a classic g-herpesvirus, expresses seven snRNAs, known as HSURs. Unlike human snRNAs, HSURs were not linked to mRNA splicing, but instead to regulating host RNA levels in the cytoplasm. Interestingly, our results indicate that HSURs predominantly localize to the nucleus, where their roles remain unknown. Additionally, we observe that HSURs selectively translocate host cytoplasmic RNA-binding proteins into the nucleus. In Project 1, we will investigate the nuclear roles of viral snRNAs to explore unknown functions for host RNA-binding proteins and to gain insights into g-herpesviral transformation. SARS-CoV-2, a large RNA virus, is the causative agent of the coronavirus disease 2019 and the source of the current pandemic. We and others have recently discovered a miRNA expressed by SARS-CoV-2, named CoV-miR-O7a, which downregulates host genes involved inter alia in interferon signaling. Our preliminary data show that CoV-miR-O7a is abundantly present inside SARS-CoV-2 virions. We hypothesize that CoV-miR-O7a (and perhaps other ncRNAs) are selectively incorporated into virions to allow for early manipulation of host gene expression. In Project 2, we will investigate the mechanism and significance of viral miRNA incorporation into nascent virions to understand as yet unknown aspects of SARS-CoV-2 pathogenesis and to describe the previously unexplored way in which viruses inhibit host antiviral responses. Our multidisciplinary approaches, combined with the flexibility of MIRA funding, will lead to the establishment of a unique research program centered around understanding of small RNA biology in the context of viral infection. In elucidating functions of small viral ncRNAs, this study will advance the fields of RNA biology and virology. Such knowledge can lead to identification of novel targets for treatment of viral disease, including virally-induced cancers.