C1 protein encoded in geminivirus satellite concertedly targets MKK2 and MPK4 to counter host defense
C1 protein encoded in geminivirus satellite concertedly targets MKK2 and MPK4 to counter host defense
复制标题
双子病毒卫星中编码的βC1蛋白协同靶向MKK2和MPK4来对抗宿主防御
DOI：
10.1371/journal.ppat.1007728
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发表时间：
2019-04-01
期刊：
影响因子：
6.7
通讯作者：
Zhou, Xueping
中科院分区：
文献类型：
--
作者：
Hu, Tao;Huang, Changjun;Zhou, Xueping
植物病毒已经进化出多种策略来克服宿主防御以建立感染。在这里，我们确定了宿主丝裂原活化蛋白激酶（MAPK）级联的两个组件，MKK 2和MPK 4，作为真正的目标的C1蛋白编码的betasatellite番茄黄化曲叶病毒（TYLCCNV）。C1与MKK2的激酶结构域相互作用并抑制其活性。在体内，C1通过靶向MKK2抑制鞭毛蛋白诱导的MAPK活化和下游反应。此外，C1还与MPK 4相互作用并抑制其激酶活性。TYLCCNV感染诱导MAPK级联反应的激活，MKK 2或MPK 4中的突变使植物对TYLCCNV更敏感，并且可以补充C1的缺乏。这项工作表明，第一次，植物病毒激活和抑制MAPK级联，和C1的能力，选择性地干扰宿主MAPK激活的发现说明了一种新的毒力功能和反宿主防御机制的geminivirus.Author摘要我们确定了一个植物MAPK级联，有助于防御对geminiviruses。在双生病毒感染后观察到MAPKs的快速活化。双生病毒β卫星的C1蛋白与MKK 2和MPK 4相互作用并抑制其激酶活性。此外，C1抑制鞭毛蛋白诱导的MAPK激活和下游反应。在烟草中敲除该级联反应的两个组分MKK 2或MPK 4使植物更易受双生病毒感染，并且在MKK 2或MPK 4敲除烟草中双生病毒的病毒感染不引起典型的病毒症状，表明MKK 2或MPK 4突变体可以补充病毒感染中C1的缺乏。这项研究揭示了MAPK级联作为抗病毒防御的新参与者，并说明了植物病毒如何反过来进化以抑制这一途径。
Plant viruses have evolved multiple strategies to overcome host defense to establish an infection. Here, we identified two components of a host mitogen-activated protein kinase (MAPK) cascade, MKK2 and MPK4, as bona fide targets of the C1 protein encoded by the betasatellite of tomato yellow leaf curl China virus (TYLCCNV). C1 interacts with the kinase domain of MKK2 and inhibits its activity. In vivo, C1 suppresses flagellin-induced MAPK activation and downstream responses by targeting MKK2. Furthermore, C1 also interacts with MPK4 and inhibits its kinase activity. TYLCCNV infection induces the activation of the MAPK cascade, mutation in MKK2 or MPK4 renders the plant more susceptible to TYLCCNV, and can complement the lack of C1. This work shows for the first time that a plant virus both activates and suppress a MAPK cascade, and the discovery of the ability of C1 to selectively interfere with the host MAPK activation illustrates a novel virulence function and counter-host defense mechanism of geminiviruses.Author summary We identified a plant MAPK cascade that contributes to the defense against geminiviruses. Rapid activation of MAPKs was observed upon geminivirus infection. The C1 protein of geminivirus betasatellite interacts with MKK2 and MPK4 and inhibits their kinase activity. Also, C1 suppresses flagellin-induced MAPK activation and downstream responses. Knocking out two components of this cascade, MKK2 or MPK4 in tobacco renders the plant more susceptible to geminivirus infection and virus infection of geminivirus without betasatellite induced typical virus symptom in MKK2 or MPK4 knockout tobacco, indicating that MKK2 or MPK4 mutant can complement the lack of C1 in virus infection. This study unveils MAPK cascades as novel players in anti-viral defense and illustrates how plant viruses have in turn evolved to suppress this pathway.