Functional analysis of dengue virus cyclization sequences located at the 5′ and 3′UTRs
Functional analysis of dengue virus cyclization sequences located at the 5′ and 3′UTRs
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DOI：
10.1016/j.virol.2008.01.014
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发表时间：
2008-05-25
期刊：
影响因子：
3.7
通讯作者：
Gamarnik, Andrea V.
中科院分区：
文献类型：
--
作者：
Alvarez, Diego E.;Filomatori, Claudia V.;Gamarnik, Andrea V.
黄病毒RNA复制涉及病毒基因组的环化。这一过程的模型包括基因组5'端的一个启动子元件以及长距离的RNA - RNA相互作用。存在于病毒RNA末端的两对互补序列，即5' - 3'CS和5' - 3'UAR，被认为参与登革病毒基因组的环化。对于登革病毒和其他蚊媒黄病毒，5' - 3'CS互补性对病毒复制的必要性已通过实验证明。在此，我们利用登革病毒基因组RNA和亚基因组RNA进行了一项功能分析，以研究5' - 3'UAR序列的作用。我们发现破坏5' - 3'互补性的单个突变极大地损害了病毒RNA的合成。尽管在大多数情况下，补偿性突变的引入重新建立了病毒RNA复制，但某些核苷酸被发现参与对病毒复制也很重要的替代二级结构。此外，在感染性登革病毒RNA背景下，5'或3'UAR内的突变导致自发突变，恢复了UAR碱基配对。总之，我们提出特定的UAR核苷酸以及5' - 3'UAR互补性构成了参与登革病毒基因组扩增的顺式作用信号。（c）2008爱思唯尔公司。保留所有权利。
Flavivirus RNA replication involves cyclization of the viral genome. A model for this process includes a promoter element at the 5' end of the genome and long-range RNA-RNA interactions. Two pairs of complementary sequences present at the ends of the viral RNA, known as 5'-3'CS and 5'-3' UAR, have been proposed to be involved in dengue virus genome cyclization. The requirement of 5'-3'CS complementarity for viral replication has been experimentally demonstrated for dengue and other mosquito borne flaviviruses. Here, we performed a functional analysis to study the role of 5'-3' UAR sequences using genomic and subgenomic dengue virus RNAs. We found that single mutations disrupting 5'-3' complementarity greatly compromised viral RNA synthesis. Although in most of the cases incorporation of compensatory mutations re-established viral RNA replication, certain nucleotides were found to be involved in alternative secondary structures also important for viral replication. In addition, mutations within 5' or 3'UAR in the context of an infectious dengue virus RNA resulted in spontaneous mutations that restored UAR base pairings. Together, we propose that specific UAR nucleotides as well as 5'-3'UAR complementarity constitute cis-acting signals involved in amplification of the dengue virus genome. (c) 2008 Elsevier Inc. All rights reserved.