Functional analysis of a DNA-shuffled movement protein reveals that microtubules are dispensable for the cell-to-cell movement of Tobacco mosaic virus
Functional analysis of a DNA-shuffled movement protein reveals that microtubules are dispensable for the cell-to-cell movement of Tobacco mosaic virus
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DOI：
10.1105/tpc.002303
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发表时间：
2002-06-01
期刊：
影响因子：
11.6
通讯作者：
Oparka, KJ
中科院分区：
文献类型：
--
作者：
Gillespie, T;Boevink, P;Oparka, KJ
微管与烟草花叶病毒（TMV）的病毒运动蛋白（MP）强烈相互作用，并被认为在植物细胞之间运输病毒基因组。我们描述了一种功能增强的DNA改组运动蛋白（MPR 3），它仍然与皮质内质网的顶点结合，对微管表现出有限的亲和力。显示单个氨基酸变化赋予MPR 3表型。破坏微管细胞骨架在原位与药物，或沉默的α-微管蛋白基因，没有显着的影响TMV载体表达野生型MP（MPWT）的传播，并没有阻止MPWT在胞间连丝的积累。因此，TMV的细胞间运输可以独立于微管发生。当用特异性蛋白酶体抑制剂处理表达MPWT的感染部位时，再现了MPR 3表型，表明MPR 3的降解受损。我们认为MPR 3的改善的病毒转运功能来自于逃避宿主降解途径。
Microtubules interact strongly with the viral movement protein (MP) of Tobacco mosaic virus (TMV) and are thought to transport the viral genome between plant cells. We describe a functionally enhanced DNA-shuffled movement protein (MPR3) that remained bound to the vertices of the cortical endoplasmic reticulum, showing limited affinity for microtubules. A single amino acid change was shown to confer the MPR3 phenotype. Disruption of the microtubule cytoskeleton in situ with pharmacological agents, or by silencing of the alpha-tubulin gene, had no significant effect on the spread of TMV vectors expressing wild-type MP (MPWT) and did not prevent the accumulation of MPWT in plasmodesmata. Thus, cell-to-cell trafficking of TMV can occur independently of microtubules. The MPR3 phenotype was reproduced when infection sites expressing MPWT were treated with a specific proteasome inhibitor, indicating that the degradation of MPR3 is impaired. We suggest that the improved viral transport functions of MPR3 arise from evasion of a host degradation pathway.