The Decoy Substrate of a Pathogen Effector and a Pseudokinase Specify Pathogen-Induced Modified-Self Recognition and Immunity in Plants
The Decoy Substrate of a Pathogen Effector and a Pseudokinase Specify Pathogen-Induced Modified-Self Recognition and Immunity in Plants
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病原体效应子和假激酶的诱饵底物指定植物中病原体诱导的修饰自我识别和免疫
DOI：
10.1016/j.chom.2015.08.004
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发表时间：
2015-09-09
影响因子：
30.3
通讯作者：
Zhou, Jian-Min
中科院分区：
文献类型：
--
作者：
Wang, Guoxun;Roux, Brice;Zhou, Jian-Min
在植物中，宿主对病原微生物的反应是由微生物感知和修饰自我的检测驱动的。野油菜黄单胞菌效应蛋白 AvrAC/XopAC 尿苷酰化拟南芥 BIK1 激酶以抑制基础抗性，从而增强细菌毒力。在这里，我们表明 PBL2（BIK1 的旁系同源物）同样被 AvrAC 尿苷酰化。然而，与 BIK1 相比，PBL2 尿苷酰化是宿主识别 AvrAC 以触发免疫所需的，但不是 AvrAC 毒力所必需的。因此，PBL2 充当诱饵并启用 AvrAC 检测。 AvrAC 识别还需要 ZRK 家族的 RKS1 假激酶和 NOD 样受体 ZAR1，已知 ZAR1 可以识别丁香假单胞菌效应子 HopZ1a。 ZAR1 与 RKS1 形成稳定的复合物，当后者被 AvrAC 尿苷酰化时，RKS1 特异性招募 PBL2，从而触发 ZAR1 介导的免疫。结果说明了诱饵底物和假激酶如何指定和扩展植物免疫系统的能力。
In plants, host response to pathogenic microbes is driven both by microbial perception and detection of modified-self. The Xanthomonas campestris effector protein AvrAC/XopAC uridylylates the Arabidopsis BIK1 kinase to dampen basal resistance and thereby promotes bacterial virulence. Here we show that PBL2, a paralog of BIK1, is similarly uridylylated by AvrAC. However, in contrast to BIK1, PBL2 uridylylation is specifically required for host recognition of AvrAC to trigger immunity, but not AvrAC virulence. PBL2 thus acts as a decoy and enables AvrAC detection. AvrAC recognition also requires the RKS1 pseudokinase of the ZRK family and the NOD-like receptor ZAR1, which is known to recognize the Pseudomonas syringae effector HopZ1a. ZAR1 forms a stable complex with RKS1, which specifically recruits PBL2 when the latter is uridylylated by AvrAC, triggering ZAR1-mediated immunity. The results illustrate how decoy substrates and pseudokinases can specify and expand the capacity of the plant immune system.