Fibrillar structures induced by a plant reovirus target mitochondria to activate typical apoptotic response and promote viral infection in insect vectors
Fibrillar structures induced by a plant reovirus target mitochondria to activate typical apoptotic response and promote viral infection in insect vectors
复制标题
植物呼肠孤病毒诱导的纤维结构靶向线粒体，激活典型的细胞凋亡反应并促进昆虫载体的病毒感染
DOI：
10.1371/journal.ppat.1007510
复制
发表时间：
2019-01-01
期刊：
影响因子：
6.7
通讯作者：
Wei, Taiyun
中科院分区：
文献类型：
--
作者：
Chen, Qian;Zheng, Limin;Wei, Taiyun
许多导致重大农业问题的植物病毒是通过昆虫媒介持续传播的。我们想要了解细胞凋亡是否参与了载体中的病毒感染过程。我们发现一种植物呼肠孤病毒(水稻瘤矮病毒，RGDV)在病毒复制过程中在叶蝉载体和培养的载体细胞中诱导了典型的凋亡反应，表现为线粒体变性和膜电位下降。RGDV的非结构蛋白Pns11形成的纤维状结构以线粒体外膜为靶标，可能是通过与感染病毒的叶蝉细胞或非媒介昆虫细胞中与凋亡相关的线粒体蛋白相互作用而形成的。病毒诱导的纤丝结构与线粒体的这种结合明显导致线粒体变性和膜电位降低，表明RGDV Pns11是昆虫载体细胞凋亡反应的诱导者。Caspase抑制剂处理和RNA干扰下调caspase基因表达均可减少细胞凋亡和病毒积累，而下调凋亡抑制蛋白的基因表达则促进细胞凋亡和病毒积累。因此，RGDV利用caspase依赖的细胞凋亡反应来促进病毒在昆虫载体中的感染。我们首次直接证实了由持久性植物病毒编码的非结构蛋白可以诱导典型的凋亡反应，从而有利于病毒通过昆虫载体传播。
Numerous plant viruses that cause significant agricultural problems are persistently transmitted by insect vectors. We wanted to see if apoptosis was involved in viral infection process in the vector. We found that a plant reovirus (rice gall dwarf virus, RGDV) induced typical apoptotic response during viral replication in the leafhopper vector and cultured vector cells, as demonstrated by mitochondrial degeneration and membrane potential decrease. Fibrillar structures formed by nonstructural protein Pns11 of RGDV targeted the outer membrane of mitochondria, likely by interaction with an apoptosis-related mitochondrial protein in virus-infected leafhopper cells or nonvector insect cells. Such association of virus-induced fibrillar structures with mitochondria clearly led to mitochondrial degeneration and membrane potential decrease, suggesting that RGDV Pns11 was the inducer of apoptotic response in insect vectors. A caspase inhibitor treatment and knockdown of caspase gene expression using RNA interference each reduced apoptosis and viral accumulation, while the knockdown of gene expression for the inhibitor of apoptosis protein improved apoptosis and viral accumulation. Thus, RGDV exploited caspase-dependent apoptotic response to promote viral infection in insect vectors. For the first time, we directly confirmed that a nonstructural protein encoded by a persistent plant virus can induce the typical apoptotic response to benefit viral transmission by insect vectors.