Cheng Chi-Ping, Panavas Tadas, Luo Guangxiang, Nagy Peter D
Department of Plant Pathology, Immunology and Molecular Genetics, University of Kentucky, Lexington, KY 40546, USA.
Virology. 2005 Oct 10;341(1):107-21. doi: 10.1016/j.virol.2005.06.042.
The viral RNA plays multiple roles during replication of RNA viruses, serving as a template for complementary RNA synthesis and facilitating the assembly of the viral replicase complex. These roles are coordinated by cis-acting regulatory elements, such as promoters and replication enhancers (REN). To test if these RNA elements can be used by related viral RNA-dependent RNA polymerases (RdRp), we compared the potential stimulatory effects of homologous and heterologous REN elements on complementary RNA synthesis and template-switching by the tombus- (Cucumber necrosis virus, CNV), carmovirus (Turnip crinkle virus, TCV) and hepatitis C virus (HCV) RdRps in vitro. The CNV RdRp selectively utilized its cognate REN, while discriminating against the heterologous TCV REN. On the contrary, RNA synthesis by the TCV RdRp was stimulated by the TCV REN and the heterologous tombusvirus REN with comparable efficiency. The heterologous REN elements also promoted in vitro template-switching by the TCV and HCV RdRps. Based on these observations, we propose that REN elements could facilitate intervirus recombination and post-recombinational amplification of new recombinant viruses.
病毒RNA在RNA病毒复制过程中发挥多种作用，作为互补RNA合成的模板并促进病毒复制酶复合体的组装。这些作用由顺式作用调控元件协调，如启动子和复制增强子（REN）。为了测试这些RNA元件是否能被相关的病毒RNA依赖性RNA聚合酶（RdRp）利用，我们在体外比较了同源和异源REN元件对番茄丛矮病毒（黄瓜坏死病毒，CNV）、 Carmovirus病毒（芜菁皱缩病毒，TCV）和丙型肝炎病毒（HCV）RdRp的互补RNA合成和模板转换的潜在刺激作用。CNV RdRp选择性地利用其同源REN，同时区分异源TCV REN。相反，TCV RdRp的RNA合成受到TCV REN和异源番茄丛矮病毒REN的同等效率刺激。异源REN元件也促进了TCV和HCV RdRp的体外模板转换。基于这些观察结果，我们提出REN元件可以促进病毒间重组以及新重组病毒的重组后扩增。
