Suppr超能文献

两个不同的位点对于毒力感染和变异卫星 RNA 复制是必需的,支持自发的甜菜曲顶病毒变异株。

Two distinct sites are essential for virulent infection and support of variant satellite RNA replication in spontaneous beet black scorch virus variants.

机构信息

State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, PR China.

出版信息

J Gen Virol. 2012 Dec;93(Pt 12):2718-2728. doi: 10.1099/vir.0.045641-0. Epub 2012 Sep 12.

Abstract

Spontaneous point mutations of virus genomes are important in RNA virus evolution and often result in modifications of their biological properties. Spontaneous variants of beet black scorch virus (BBSV) and its satellite (sat) RNA were generated from cDNA clones by serial propagation in Chenopodium amaranticolor and Nicotiana benthamiana. Inoculation with recombinant RNAs synthesized in vitro revealed BBSV variants with divergent infectious phenotypes that affected either symptom expression or replication of satRNA variants. Sequence alignments showed a correlation between the phenotypes and distinct BBSV genomic loci in the 3'UTR or in the domain encoding the viral replicase. Comparative analysis between a virulent variant, BBSV-m294, and the wild-type (wt) BBSV by site-directed mutagenesis indicated that a single-nucleotide substitution of a uridine to a guanine at nt 3477 in the 3'UTR was responsible for significant increases in viral pathogenicity. Gain-of-function analyses demonstrated that the ability of the BBSV variants to support replication of variant satRNAs was mainly determined by aa 516 in the P82 replicase. In this case, an arginine substitution for a glutamine residue was essential for high levels of replication, and alterations of other residues surrounding position 516 in the wtBBSV isolate led to only minor phenotypic effects. These results provide evidence that divergence of virus functions affecting pathogenicity and supporting parasitic replication can be determined by a single genetic site, either a nucleotide or an amino acid. The results suggest that complex interactions occur between virus and associated satRNAs during virus evolution.

摘要

病毒基因组的自发点突变在 RNA 病毒进化中很重要,通常会导致其生物学特性的改变。通过在苋色藜和烟草中连续繁殖 cDNA 克隆,生成了甜菜黄斑坏死病毒 (BBSV) 及其卫星 (sat) RNA 的自发变体。用体外合成的重组 RNA 接种,揭示了具有不同感染表型的 BBSV 变体,这些变体影响 satRNA 变体的症状表达或复制。序列比对表明表型与 3'UTR 或编码病毒复制酶的结构域中的 BBSV 基因组特定位置之间存在相关性。通过定点诱变对一种毒力变体 BBSV-m294 和野生型 (wt) BBSV 进行比较分析表明,3'UTR 中尿嘧啶到鸟嘌呤的单核苷酸取代是导致病毒致病性显著增加的原因。功能获得分析表明,BBSV 变体支持变体 satRNA 复制的能力主要由 P82 复制酶中的 aa516 决定。在这种情况下,精氨酸取代谷氨酰胺残基对于高水平的复制是必需的,而 wtBBSV 分离株中 aa516 周围位置的其他残基的改变仅导致轻微的表型效应。这些结果提供了证据,表明影响致病性和支持寄生复制的病毒功能的差异可以由单个遗传位点决定,无论是核苷酸还是氨基酸。结果表明,在病毒进化过程中,病毒和相关 satRNA 之间会发生复杂的相互作用。

文献AI研究员

20分钟写一篇综述,助力文献阅读效率提升50倍。

立即体验

用中文搜PubMed

大模型驱动的PubMed中文搜索引擎

马上搜索

文档翻译

学术文献翻译模型,支持多种主流文档格式。

立即体验