The C-terminal region of the Turnip mosaic virus P3 protein is essential for viral infection via targeting P3 to the viral replication complex
The C-terminal region of the Turnip mosaic virus P3 protein is essential for viral infection via targeting P3 to the viral replication complex
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DOI：
10.1016/j.virol.2017.07.016
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发表时间：
2017-10-01
期刊：
影响因子：
3.7
通讯作者：
Wang, Aiming
中科院分区：
文献类型：
--
作者：
Cui, Xiaoyan;Yaghmaiean, Hoda;Wang, Aiming
与其他正链RNA病毒一样，植物马铃薯Y病毒在修饰的细胞膜上组装病毒复制复合体(VRC)。马铃薯Y病毒编码两种膜蛋白6K2和P3。前者在膜相关VRCs的形成中起着关键作用。然而，P3仍然是特征最少的马铃薯Y病毒蛋白之一。P3顺反子编码P3和P3N-PIPO，P3N-PIPO是由RNA聚合酶滑移产生的。在这项研究中，我们发现芜菁花叶病毒(TuMV)的P3N-PIPO是病毒细胞间运动所必需的，但不是病毒复制所必需的。我们证明了P3(P3C)的C-末端区域对于P3形成细胞质点状包裹体和靶向VRC是必不可少的。我们揭示了缺乏P3C的TuMV突变体是复制缺陷的。综上所述，这些数据表明，P3顺反子具有两种截然不同的功能：P3N-PIPO作为一种专用运动蛋白和P3作为VRC的重要组成部分。
Like other positive-strand RNA viruses, plant potyviruses assemble viral replication complexes (VRCs) on modified cellular membranes. Potyviruses encode two membrane proteins, 6K2 and P3. The former is known to play pivotal roles in the formation of membrane-associated VRCs. However, P3 remains to be one of the least characterized potyviral proteins. The P3 cistron codes for P3 as well as P3N-PIPO which results from RNA polymerase slippage. In this study, we show that the P3N-PIPO of Turnip mosaic virus (TuMV) is required for viral cell-to-cell movement but not for viral replication. We demonstrate that the C-terminal region of P3 (P3C) is indispensable for P3 to form cytoplasmic punctate inclusions and target VRCs. We reveal that TuMV mutants that lack P3C are replication-defective. Taken together, these data suggest that the P3 cistron has two distinct functions: P3N-PIPO as a dedicated movement protein and P3 as an essential component of the VRC.