Bacterial effector NleL promotes enterohemorrhagic E. coli-induced attaching and effacing lesions by ubiquitylating and inactivating JNK.
Bacterial effector NleL promotes enterohemorrhagic E. coli-induced attaching and effacing lesions by ubiquitylating and inactivating JNK.
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细菌效应器 NleL 通过泛素化和灭活 JNK 来促进肠出血性大肠杆菌诱导的附着和消除病变。
DOI：
10.1371/journal.ppat.1006534
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发表时间：
2017-07
期刊：
影响因子：
6.7
通讯作者：
Hu R
中科院分区：
文献类型：
--
作者：
Sheng X;You Q;Zhu H;Chang Z;Li Q;Wang H;Wang C;Wang H;Hui L;Du C;Xie X;Zeng R;Lin A;Shi D;Ruan K;Yan J;Gao GF;Shao F;Hu R
肠出血性大肠杆菌(EHEC)是一种引起人类腹泻的主要病原体，在哺乳动物细胞上产生附着和消失(A/E)病变，其特征是形成肌动蛋白底物。EHEC O157：H7的细菌T3SS效应子NleL在体外被证明是一种Hect样的E3连接酶，但其生物学功能和宿主靶点仍不清楚。在此，我们报告需要NleL来有效促进EHEC诱导的A/E病变和细菌感染。此外，人c-Jun氨基末端激酶(JNKs)被鉴定为NleL的主要底物。NleL诱导的JNK泛素化，特别是JNK的Lys 68残基的单一泛素化，削弱了JNK与上游激酶MKK7的相互作用，从而扰乱了JNK的磷酸化和激活。这随后抑制了激活蛋白-1(AP-1)的转录活性，AP-1调控EHEC诱导的肌动蛋白底座的形成。此外，JNK在宿主细胞中被敲除或抑制，补充了EHEC感染中NleL的缺陷。因此，我们证明效应蛋白NleL通过靶向宿主JNK来增强EHEC感染宿主细胞的能力，并阐明泛素化在调节JNK磷酸化中的抑制作用。肠出血性大肠杆菌(EHEC)可导致动物和人类结肠形成附着和消失(A/E)病变，导致严重的细菌感染。NleL是EHEC O157：H7的一种E3泛素连接酶，是细菌III型分泌效应因子之一，可能参与A/E病变的调节。然而，NleL的确切主办目标和详细的机械性行动仍不清楚。在这里，我们报告了效应蛋白NleL通过靶向宿主JNK蛋白有效地促进EHEC诱导的A/E病变和细菌感染。特别是，我们发现NleL介导的JNK泛素化取消了宿主JNK的磷酸化和激活，从而抑制了宿主JNK/AP-1信号通路，有利于EHEC介导的肌动蛋白基座在哺乳动物细胞表面的形成。综上所述，我们的工作不仅发现了NleL在EHEC感染过程中促进A/E病变的作用，而且揭示了宿主JNK蛋白的一种新的调控机制。
As a major diarrheagenic human pathogen, enterohemorrhagic Escherichia coli (EHEC) produce attaching and effacing (A/E) lesions, characterized by the formation of actin pedestals, on mammalian cells. A bacterial T3SS effector NleL from EHEC O157:H7 was recently shown to be a HECT-like E3 ligase in vitro, but its biological functions and host targets remain elusive. Here, we report that NleL is required to effectively promote EHEC-induced A/E lesions and bacterial infection. Furthermore, human c-Jun NH2-terminal kinases (JNKs) were identified as primary substrates of NleL. NleL-induced JNK ubiquitylation, particularly mono-ubiquitylation at the Lys 68 residue of JNK, impairs JNK’s interaction with an upstream kinase MKK7, thus disrupting JNK phosphorylation and activation. This subsequently suppresses the transcriptional activity of activator protein-1 (AP-1), which modulates the formation of the EHEC-induced actin pedestals. Moreover, JNK knockdown or inhibition in host cells complements NleL deficiency in EHEC infection. Thus, we demonstrate that the effector protein NleL enhances the ability of EHEC to infect host cells by targeting host JNK, and elucidate an inhibitory role of ubiquitylation in regulating JNK phosphorylation. Enterohemorrhagic Escherichia coli (EHEC) can cause attaching and effacing (A/E) lesions to form in the colons of animals and humans, contributing to severe bacterial infection. NleL, an E3 ubiquitin ligase from EHEC O157:H7 is one of the bacterial type III secretion effectors that may be involved in the regulation of A/E lesions. However, NleL’s exact host targets and the detailed mechanistic actions are still unclear. Here, we report that the effector protein NleL effectively promotes EHEC-induced A/E lesions and bacterial infection by targeting the host JNK protein. Specifically, we find that NleL-mediated JNK ubiquitylation abolishes phosphorylation and activation of host JNK, subsequently suppressing the host JNK/AP-1 signaling pathway to favor the formation of EHEC-mediated actin pedestals on the surface of mammalian cells. Collectively, our work has not only discovered the A/E lesion-promoting function of NleL during EHEC infection, but also revealed a novel regulatory mechanism of host JNK protein.
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影响因子：
15.9
作者：
DONNENBERG, MS;TACKET, CO;LEVINE, MM
通讯作者：
LEVINE, MM
影响因子：
64.8
作者：
Li, Wei;Tu, Daqi;Ye, Yihong
通讯作者：
Ye, Yihong
影响因子：
3.6
作者：
Deng, WY;Vallance, BA;Finlay, BB
通讯作者：
Finlay, BB
DOI：
10.1073/pnas.120163297
发表时间：
2000-06-06
影响因子：
11.1
作者：
Datsenko, KA;Wanner, BL
通讯作者：
Wanner, BL
影响因子：
14.8
作者：
Hubatsch, Ina;Ragnarsson, Eva G. E.;Artursson, Per
通讯作者：
Artursson, Per