The tripartite virions of the brome mosaic virus have distinct physical properties that affect the timing of the infection process.
The tripartite virions of the brome mosaic virus have distinct physical properties that affect the timing of the infection process.
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雀麦花叶病毒的三联病毒体具有独特的物理特性，影响感染过程的时间。
DOI：
10.1128/jvi.00377-14
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发表时间：
2014
影响因子：
5.4
通讯作者：
Kao,CCheng
中科院分区：
文献类型：
--
作者：
Vaughan,Robert;Tragesser,Brady;Ni,Peng;Ma,Xiang;Dragnea,Bogdan;Kao,CCheng
构成雀麦花叶病毒（BMV）的病毒体的三个亚群以前被认为是不可区分的。这项工作测试了BMV病毒体中不同的衣壳-RNA相互作用允许不同的病毒RNA释放速率的假设。一些结果支持衣壳和BMV基因组RNA之间的不同相互作用。首先，BMV外壳蛋白（CP）的前8个残基的缺失导致含有RNA 1的颗粒具有改变的形态，而含有RNA 2的颗粒不受影响。第二，通过密度梯度分离的BMV颗粒的子集被发现具有不同的生理化学性质，所述BMV颗粒被分离成富含RNA 1（B1）和RNA 2和RNA 3/4（B2.3/4）的池。与B2.3/4颗粒相比，B1颗粒对蛋白酶消化更敏感，并且通过原子力显微镜对纳米压痕具有更大的抵抗力，并且对核酸酶消化的敏感性增加。作图研究表明，CP的N-末端富含精氨酸的尾部部分可以与RNA 1相互作用。在推定的RNA 1接触残基的突变分析，严重减少BMV RNA 1的糖苷化，而不影响RNA 2的糖苷化。最后，在感染植物的过程中，更容易释放的RNA 1在感染早期积累到更高的水平。重要的是，基因组包装在不同病毒体中的病毒理论上可以在不同的时间释放基因组，以调节基因表达的时间。使用由三个粒子组成的RNA病毒，我们证明了其中一个病毒粒子中的RNA比其他两个病毒粒子更容易在体外释放。差异RNA释放是由于病毒衣壳蛋白和RNA之间的不同相互作用。RNA释放的容易程度也与RNA在受感染植物中的更快积累有关。我们的研究确定了一个新的作用capture-RNA相互作用的调节病毒感染。
The three subsets of virions that comprise the Brome mosaic virus (BMV) were previously thought to be indistinguishable. This work tested the hypothesis that distinct capsid-RNA interactions in the BMV virions allow different rates of viral RNA release. Several results support distinct interactions between the capsid and the BMV genomic RNAs. First, the deletion of the first eight residues of the BMV coat protein (CP) resulted in the RNA1-containing particles having altered morphologies, while those containing RNA2 were unaffected. Second, subsets of the BMV particles separated by density gradients into a pool enriched for RNA1 (B1) and for RNA2 and RNA3/4 (B2.3/4) were found to have different physiochemical properties. Compared to the B2.3/4 particles, the B1 particles were more sensitive to protease digestion and had greater resistivity to nanoindentation by atomic force microscopy and increased susceptibility to nuclease digestion. Mapping studies showed that portions of the arginine-rich N-terminal tail of the CP could interact with RNA1. Mutational analysis in the putative RNA1-contacting residues severely reduced encapsidation of BMV RNA1 without affecting the encapsidation of RNA2. Finally, during infection of plants, the more easily released RNA1 accumulated to higher levels early in the infection.IMPORTANCEViruses with genomes packaged in distinct virions could theoretically release the genomes at different times to regulate the timing of gene expression. Using an RNA virus composed of three particles, we demonstrated that the RNA in one of the virions is released more easily than the other twoin vitro. The differential RNA release is due to distinct interactions between the viral capsid protein and the RNAs. The ease of RNA release is also correlated with the more rapid accumulation of that RNA in infected plants. Our study identified a novel role for capsid-RNA interactions in the regulation of a viral infection.