A sequence of basic residues in the porcine circovirus type 2 capsid protein is crucial for its co-expression and co-localization with the replication protein
A sequence of basic residues in the porcine circovirus type 2 capsid protein is crucial for its co-expression and co-localization with the replication protein
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DOI：
10.1099/jgv.0.000302
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发表时间：
2015-12-01
影响因子：
3.8
通讯作者：
Nauwynck, Hans J.
中科院分区：
文献类型：
--
作者：
Huang, Liping;Van Renne, Nicolaas;Nauwynck, Hans J.
猪圆环病毒2型（PCV 2）编码两种主要蛋白：复制蛋白（Rep）和衣壳蛋白（Cap）。Cap显示位于衣壳内部的保守的碱性残基延伸，其作用迄今未知。我们使用反向遗传学方法来研究其功能，发现这些氨基酸的突变阻碍了Cap mRNA的翻译，阻碍了Cap/Rep共定位，产生了不合适的病毒。有趣的是，与不同基因型的WT PCV 2共转染部分挽救了突变体Cap表达，显示了这种基本模式对于Cap mRNA有效翻译成蛋白质的重要性。我们的研究结果表明，Cap和Rep是相互独立表达的，并且Cap的氨基酸序列对病毒繁殖至关重要。这项研究提供了一种研究不适合PCV 2病毒粒子的方法，并提供了新的见解PCV 2的细胞内生活方式。
Porcine circovirus type 2 (PCV2) encodes two major proteins: the replication protein (Rep) and the capsid protein (Cap). Cap displays a conserved stretch of basic residues situated on the inside of the capsid, whose role is so far unknown. We used a reverse-genetics approach to investigate its function and found that mutations in these amino acids hindered Cap mRNA translation and hampered Cap/Rep co-localization, yielding unfit viruses. Intriguingly, co-transfection with a WT PCV2 of a different genotype partially rescued mutant Cap expression, showing the importance of this basic pattern for efficient translation of Cap mRNA into protein. Our results show that Cap and Rep are expressed independently of each other, and that this amino acid sequence of Cap is vital for virus propagation. This study provides a method for studying unfit PCV2 virions and offers new insights into the intracellular modus vivendi of PCV2.