Palmitoylation of γb protein directs a dynamic switch between Barley stripe mosaic virus replication and movement
Palmitoylation of γb protein directs a dynamic switch between Barley stripe mosaic virus replication and movement
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DOI：
10.15252/embj.2021110060
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发表时间：
2022-06
期刊：
影响因子：
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通讯作者：
Ning Yue;Zhihao Jiang;Xuan Zhang;Zhenggang Li;Xueting Wang;Zhiyan Wen;Zongyu Gao;Q. Pi
中科院分区：
文献类型：
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作者：
Ning Yue;Zhihao Jiang;Xuan Zhang;Zhenggang Li;Xueting Wang;Zhiyan Wen;Zongyu Gao;Q. Pi
病毒复制和运动密切相关；然而，调节复制和随后运动之间转变的分子机制在很大程度上仍然未知。我们之前已经证明大麦条纹花叶病毒(BSMV) γb蛋白通过与αa复制酶和TGB1运动蛋白相互作用促进病毒的复制和运动。本研究发现，γ - b在烟叶中的Cys‐10、Cys‐19和Cys‐60位点棕榈酰化，支持BSMV感染。有趣的是，非棕榈酰化的γb蛋白锚定在叶绿体复制位点并增强BSMV的复制，而棕榈酰化的γb蛋白将TGB1招募到叶绿体并形成病毒复制运动的中间复合物。在复制后期，γ - b与NbPAT15和NbPAT21相互作用，并在叶绿体外围棕榈酰化，从而将病毒复制转移到细胞内和细胞间运动。我们还发现棕榈酰化的γ - b通过与nbrrem1相互作用来抑制间连丝处胼胝质沉积，从而促进病毒细胞间的运动。总之，我们的实验揭示了一个模型，其中γ - b棕榈酰化指导感染期间BSMV复制和运动事件之间的动态切换。
Viral replication and movement are intimately linked; however, the molecular mechanisms regulating the transition between replication and subsequent movement remain largely unknown. We previously demonstrated that the Barley stripe mosaic virus (BSMV) γb protein promotes viral replication and movement by interacting with the αa replicase and TGB1 movement proteins. Here, we found that γb is palmitoylated at Cys‐10, Cys‐19, and Cys‐60 in Nicotiana benthamiana, which supports BSMV infection. Intriguingly, non‐palmitoylated γb is anchored to chloroplast replication sites and enhances BSMV replication, whereas palmitoylated γb protein recruits TGB1 to the chloroplasts and forms viral replication‐movement intermediate complexes. At the late stages of replication, γb interacts with NbPAT15 and NbPAT21 and is palmitoylated at the chloroplast periphery, thereby shifting viral replication to intracellular and intercellular movement. We also show that palmitoylated γb promotes virus cell‐to‐cell movement by interacting with NbREM1 to inhibit callose deposition at the plasmodesmata. Altogether, our experiments reveal a model whereby palmitoylation of γb directs a dynamic switch between BSMV replication and movement events during infection.