Virus Evolution Through Horizontal Gene Transfer

通过水平基因转移的病毒进化

• 批准号: 10157165
• 负责人: Stephen Goldstein
• 金额: $ 6.64万
• 依托单位: UNIVERSITY OF UTAH
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-06-01 至 2024-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10157165
• 关键词: Antiviral Agents; Archaea; Archaeal Genes; Automobile Driving; Bacteria; Bacterial Genes; Biochemistry; Cell Culture Techniques; Cells; Complement; Complementary DNA; Complex; Computational Technique; Computer Analysis; Cytoplasm; DNA Sequence; DNA Transposable Elements; DNA Viruses; Data; Distal; Ecosystem; Ectopic Expression; Engineering; Environment; Eukaryota; Evolution; Family; Frequencies; Genes; Genetic; Genetic Materials; Genetic Variation; Genome; Growth; Homologous Gene; Horizontal Gene Transfer; Immune; Immune response; Immunofluorescence Immunologic; In Vitro; Insertional Mutagenesis; L1 Elements; Life; Mammalian Cell; Maps; Mediating; Messenger RNA; Microbe; Modeling; Modernization; Molecular Biology; Molecular Computations; Movement; Organism; Phosphorylation Site; Phylogenetic Analysis; Play; Population; Poxviridae; Process; Protein Inhibition; Proteins; Pseudogenes; RNA-Directed DNA Polymerase; Recording of previous events; Regulation; Retrotransposition; Retrotransposon; Role; Serial Passage; Shapes; Source; Structure; System; Taxonomy; Testing; Training; Vaccinia Virus Study; Vaccinia virus; Vertebrates; Viral; Viral Genes; Viral Genome; Virus; Virus Diseases; Virus Replication; Work; Yeasts; co-infection; genetic element; genetic information; improved; inhibitor/antagonist; insight; melting; nanopore; next generation sequencing; novel; post-doctoral training; pressure; protein kinase R; protein kinase inhibitor; recombinant virus; theories; viral fitness; virology; yeast protein

Project Summary Horizontal gene transfer (HGT) is a well characterized phenomenon driving the evolution and genetic diversity of bacteria but its underlying mechanisms and consequences in the context of viral evolution are far less well- understood. Poxviruses and other large DNA viruses encode numerous genes of clear cellular origin. I aim to investigate how they get there and evolve following their acquisition. We have demonstrated that LINE-1 (L1) retrotransposons play a key role in the transfer of cellular genes into poxvirus genomes but do not yet understand the dynamics of how this occurs without inducing catastrophic insertional mutagenesis. How newly acquired genes evolve proviral functions and avoid deletion due to functional redundancy with their cellular ancestor. The central hypothesis of this proposal is that L1 insertions into poxvirus genomes are enriched in distal regions of the genome, avoiding disruption of essential core genes, where they can evolve to benefit the virus. I will focus on two major outstanding questions emerging from this hypothesis. In Aim 1 I will characterize the interaction between virus replication and cellular L1 machinery. This will comprise spatially defining the interaction within the cytoplasm, understanding if and how L1 activity impacts viral replication, and comprehensively characterizing the frequency and distribution of L1-mediated insertions into the viral genome. To do so I will use a combination of experimental and computational techniques spanning molecular biology, biochemistry, genetics, and next-generation sequencing. In Aim 2 I will seek to elucidate the origin and evolution of poxvirus K3L, a host-derived inhibitor of the antiviral effector PKR. K3L is a structural homolog of vertebrate eIF2 that competitively inhibits PKR-induced translational shutoff. Compared to eIF2 K3L is dramatically truncated and lacks a phosphorylation site, and so cannot mediate the antiviral functions downstream of PKR. Despite this homology, computational and phylogenetic analysis suggests K3L is most closely related to the aIF2 protein of methanogenic archaea and may not have been acquired from the host cell of an ancestral poxvirus but rather from microbes occupying similar or overlapping ecological space. Since my original submission, I have generated new preliminary data that M. fervens aIF2 inhibits vertebrate PKR, giving experimental support to my computational work. I will confirm and expand on these results in mammalian cell culture, and use experimental evolution to model the adaptation of newly acquired viral genes. The recent identification of archaeal-origin genes in other DNA viruses, provides further support for my hypothesis, but K3L would be the first known example in viruses of multicellular eukaryotes. A picture is emerging of viruses as melting pots in nodes of diverse genetic exchange and my proposed studies will illuminate the participation of a new family of viruses in these ecological spaces. These studies will advance our understanding of the process of viral co-option of cellular genes as well as explore unexpected mechanisms underlying the genetic diversity of viruses and the ecological spaces they occupy.

项目摘要 水平基因转移(HGT)是推动进化和遗传多样性的一种典型现象 但在病毒进化的背景下，其潜在的机制和后果远没有那么好- 明白了。痘病毒和其他大型DNA病毒编码大量明显起源于细胞的基因。我的目标是 调查他们是如何做到这一点的，并在收购后不断发展。我们已经演示了线路-1(L1) 反转录转座子在将细胞基因转移到痘病毒基因组中起着关键作用，但目前还不是 了解如何在不引发灾难性的插入突变的情况下发生这种情况的动力学。有多新 获得性基因进化前病毒功能，避免因其细胞功能冗余而缺失 祖先。这一提议的中心假设是，L1插入到痘病毒基因组中的片段在 基因组的远端区域，避免基本核心基因的破坏，在那里它们可以进化成有利于 病毒。我将集中讨论这一假说产生的两个主要悬而未决的问题。在《目标1》中我会 描述病毒复制和细胞L1机制之间的相互作用。这将包括空间上的 定义细胞质内的相互作用，了解L1活动是否以及如何影响病毒复制，以及 全面表征L1介导的插入病毒基因组的频率和分布。 为此，我将使用跨越分子生物学的实验和计算技术的组合， 生物化学、遗传学和下一代测序。在目标2中，我将试图澄清起源和 痘病毒K3L，一种宿主衍生的抗病毒效应物PKR的抑制物的进化。K3L是一个结构上的同源 脊椎动物eif2竞争性地抑制PKR诱导的翻译关闭。与eif2相比，K3L 显著截断，缺乏磷酸化位点，因此不能介导抗病毒功能 在PKR下游。尽管有这种同源性，但计算和系统发育分析表明，K3L是 与产甲烷古菌的aif2蛋白密切相关，可能不是从宿主那里获得的 来自祖先痘病毒的细胞，而不是来自占据相似或重叠生态空间的微生物。自.以来 我最初提交的，我已经产生了新的初步数据，M.Fervens AIF2抑制脊椎动物PKR， 为我的计算工作提供实验支持。我将在以下文件中确认和详述这些结果 哺乳动物细胞培养，并利用实验进化来模拟新获得的病毒基因的适应。 最近在其他DNA病毒中发现的古细菌起源基因，为我的 假说，但K3L将是多细胞真核生物病毒中已知的第一个例子。一张照片是 病毒在不同遗传交换的节点中作为熔炉出现，我提出的研究将 阐明一个新的病毒家族在这些生态空间中的参与。这些研究将取得进展 我们对细胞基因病毒共选过程的理解以及对意想不到的探索 病毒遗传多样性的潜在机制及其所占据的生态空间。