A conserved RNA structure is essential for a satellite RNA-mediated inhibition of helper virus accumulation
A conserved RNA structure is essential for a satellite RNA-mediated inhibition of helper virus accumulation
复制标题
保守的 RNA 结构对于卫星 RNA 介导的辅助病毒积累抑制至关重要
DOI：
10.1093/nar/gkz564
复制
发表时间：
2019-09-05
影响因子：
14.9
通讯作者：
Du, Zhiyou
中科院分区：
文献类型：
--
作者：
He, Lu;Wang, Qian;Du, Zhiyou
摘要卫星RNA（satRNAs）是一类寄生的非编码RNA，它必须与辅助病毒竞争有限的病毒和/或宿主资源以进行有效的复制，从而减少病毒的积累和症状的表达。在这里，我们报告了黄瓜花叶病毒（CMV）相关的卫星RNA（sat-T1），改善CMV诱导的症状，伴随着病毒基因组RNA的积累显着减少1和2，其中编码的病毒复制酶的组件。反式复制试验表明，减少的积累是复制竞争的结果。sat-T1负责抑制病毒RNA积累的结构基础被确定为包含两个生物学重要发夹的三向分支二级结构。一个是不可或缺的辅助病毒抑制，和其他从事形成的三级假结结构，这是必不可少的sat-T1的生存。含有假结的二级结构是CMV卫星RNA中实验鉴定的第一个具有生物表型的RNA元件，并且它在大多数CMV卫星RNA中结构保守。因此，这可能是CMV卫星RNA通过新鉴定的RNA结构抑制辅助病毒积累的通用方法。
Abstract As a class of parasitic, non-coding RNAs, satellite RNAs (satRNAs) have to compete with their helper virus for limited amounts of viral and/or host resources for efficient replication, by which they usually reduce viral accumulation and symptom expression. Here, we report a cucumber mosaic virus (CMV)-associated satRNA (sat-T1) that ameliorated CMV-induced symptoms, accompanied with a significant reduction in the accumulation of viral genomic RNAs 1 and 2, which encode components of the viral replicase. Intrans replication assays suggest that the reduced accumulation is the outcome of replication competition. The structural basis of sat-T1 responsible for the inhibition of viral RNA accumulation was determined to be a three-way branched secondary structure that contains two biologically important hairpins. One is indispensable for the helper virus inhibition, and the other engages in formation of a tertiary pseudoknot structure that is essential for sat-T1 survival. The secondary structure containing the pseudoknot is the first RNA element with a biological phenotype experimentally identified in CMV satRNAs, and it is structurally conserved in most CMV satRNAs. Thus, this may be a generic method for CMV satRNAs to inhibit the accumulation of the helper virus via the newly-identified RNA structure.