Identification of distinct steps during tubule formation by the movement protein of Cowpea mosaic virus.
Identification of distinct steps during tubule formation by the movement protein of Cowpea mosaic virus.
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DOI：
10.1099/vir.0.19553-0
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发表时间：
2003-12
期刊：
影响因子：
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通讯作者：
J. Pouwels;N. Kornet;N. V. van Bers;Teun Guighelaar;J. V. van Lent;T. Bisseling;J. Wellink
中科院分区：
文献类型：
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作者：
J. Pouwels;N. Kornet;N. V. van Bers;Teun Guighelaar;J. V. van Lent;T. Bisseling;J. Wellink
豌豆花叶病毒(CPMV)的运动蛋白(MP)在受感染的植物体内通过胞间连丝形成小管，使病毒颗粒在细胞间移动。原生质体和植物中融合了GFP的突变MPS的定位研究发现，MP中的几个功能域参与了小管形成的不同步骤。共接种实验和观察到其中一个C端缺失突变体在质膜中均匀积累，表明二聚体或多聚体MP首先靶向质膜。在质膜上，MP迅速聚集在周围的点状斑点，由此启动了小管的形成。其中一个突变的MPS在原生质体上形成含有病毒颗粒的小管，但不能支持植物中细胞到细胞的运动。观察到这种突变的MP在细胞中积累到比wt MP更高的水平，而没有积累在感染细胞对面的细胞壁中，这表明邻近的未感染细胞中的小管破裂或拆解是细胞间移动所必需的。
The movement protein (MP) of Cowpea mosaic virus (CPMV) forms tubules through plasmodesmata in infected plants thus enabling virus particles to move from cell to cell. Localization studies of mutant MPs fused to GFP in protoplasts and plants identified several functional domains within the MP that are involved in distinct steps during tubule formation. Coinoculation experiments and the observation that one of the C-terminal deletion mutants accumulated uniformly in the plasma membrane suggest that dimeric or multimeric MP is first targeted to the plasma membrane. At the plasma membrane the MP quickly accumulates in peripheral punctuate spots, from which tubule formation is initiated. One of the mutant MPs formed tubules containing virus particles on protoplasts, but could not support cell-to-cell movement in plants. The observations that this mutant MP accumulated to a higher level in the cell than wt MP and did not accumulate in the cell wall opposite infected cells suggest that breakdown or disassembly of tubules in neighbouring, uninfected cells is required for cell-to-cell movement.