Dynamics of picornavirus RNA replication within infected cells
Dynamics of picornavirus RNA replication within infected cells
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DOI：
10.1099/vir.0.83385-0
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发表时间：
2008-02-01
影响因子：
3.8
通讯作者：
Normann, Preben
中科院分区：
文献类型：
--
作者：
Belsham, Graham J.;Normann, Preben
低浓度的胍可抑制许多小核糖核酸病毒的复制。胍抗性突变体很容易分离，突变映射到2C蛋白的编码区。使用体外复制测定，先前已经确定胍阻断负链合成的起始。我们现在已经检查了感染猪水泡病病毒（一种肠道病毒）或口蹄疫病毒的细胞内RNA复制的动态，通过定量RT-PCR测量，并受存在或不存在胍的调节。在从感染的细胞中除去胍后，RNA复制在显著的滞后期后发生。这种RNA合成的恢复需要从头蛋白质合成。病毒RNA可以在细胞内维持至少72小时，在没有明显的复制，但胍抗性病毒可以成为主要的。已经鉴定了赋予对猪水泡病病毒和口蹄疫病毒的胍抗性的2C蛋白内的氨基酸取代。即使RNA合成已经建立，胍的加入也会对RNA复制水平产生重大影响。因此，RNA合成中的胍敏感步骤在细胞中的整个病毒生命周期中都很重要。
Replication of many picornaviruses is inhibited by low concentrations of guanidine. Guanidine-resistant mutants are readily isolated and the mutations map to the coding region for the 2C protein. Using in vitro replication assays it has been determined previously that guanidine blocks the initiation of negative-strand synthesis. We have now examined the dynamics of RNA replication, measured by quantitative RT-PCR, within cells infected with either swine vesicular disease virus (an enterovirus) or foot-and-mouth disease virus as regulated by the presence or absence of guanidine. Following the removal of guanidine from the infected cells, RNA replication occurs after a significant lag phase. This restoration of RNA synthesis requires de novo protein synthesis. Viral RNA can be maintained for at least 72 h within cells in the absence of apparent replication but guanidine-resistant virus can become predominant. Amino acid substitutions within the 2C protein that confer guanidine resistance to swine vesicular disease virus and foot-and-mouth disease virus have been identified. Even when RNA synthesis is well established, the addition of guanidine has a major impact on the level of RNA replication. Thus, the guanidine-sensitive step in RNA synthesis is important throughout the virus life cycle in cells.