A host target of a bacterial cysteine protease virulence effector plays a key role in convergent evolution of plant innate immune system receptors
A host target of a bacterial cysteine protease virulence effector plays a key role in convergent evolution of plant innate immune system receptors
复制标题
DOI：
10.1111/nph.16218
复制
发表时间：
2019-10-31
期刊：
影响因子：
9.4
通讯作者：
Sohn, Kee Hoon
中科院分区：
文献类型：
--
作者：
Prokchorchik, Maxim;Choi, Sera;Sohn, Kee Hoon
病原体分泌的一些毒力效应物靶向宿主蛋白并诱导由核苷酸结合和富含亮氨酸重复序列（NLR）免疫受体监测的生化修饰。拟南芥RIN 4蛋白（AtRIN 4：RPM 1-interacting protein 4）同源物存在于不同的植物物种中，并被包括半胱氨酸蛋白酶AvrRpt 2在内的几种细菌III型效应蛋白靶向。RIN 4被来自各种植物物种的几个独立进化的NLR“保护”，包括拟南芥RPS 2。最近，有研究表明，来自野生苹果亲戚的MR 5 NLR可以识别来自梨火疫病菌的AvrRpt 2效应子，但这种识别的细节仍不清楚。目前的贡献报告的AvrRpt 2识别的机制，独立进化的NLR，MR 5从苹果和RPS 2，这两者都需要蛋白水解处理的RIN 4激活。这表明苹果RIN 4（MdRIN 4）而不是AtRIN 4的C-末端切割产物对于MR 5活化是必需和充分的。此外，在AtRIN 4和MdRIN 4中的两个多态性残基被鉴定为在NLR的调节和与NLR的物理关联中至关重要。有人提出，在RIN 4的多态性从远亲植物物种允许它保持一个效应器的目标，同时保持与多个NLR的兼容性。
Some virulence effectors secreted from pathogens target host proteins and induce biochemical modifications that are monitored by nucleotide-binding and leucine-rich repeat (NLR) immune receptors. Arabidopsis RIN4 protein (AtRIN4: RPM1-interacting protein 4) homologs are present in diverse plant species and targeted by several bacterial type III effector proteins including the cysteine protease AvrRpt2. RIN4 is 'guarded' by several independently evolved NLRs from various plant species, including Arabidopsis RPS2. Recently, it was shown that the MR5 NLR from a wild apple relative can recognize the AvrRpt2 effector from Erwinia amylovora, but the details of this recognition remained unclear. The present contribution reports the mechanism of AvrRpt2 recognition by independently evolved NLRs, MR5 from apple and RPS2, both of which require proteolytically processed RIN4 for activation. It shows that the C-terminal cleaved product of apple RIN4 (MdRIN4) but not AtRIN4 is necessary and sufficient for MR5 activation. Additionally, two polymorphic residues in AtRIN4 and MdRIN4 are identified that are crucial in the regulation of and physical association with NLRs. It is proposed that polymorphisms in RIN4 from distantly related plant species allow it to remain an effector target while maintaining compatibility with multiple NLRs.