Dissecting the role of the Tir:Nck and Tir:IRTKS/IRSp53 signalling pathways in vivo.
Dissecting the role of the Tir:Nck and Tir:IRTKS/IRSp53 signalling pathways in vivo.
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DOI：
10.1111/j.1365-2958.2009.06938.x
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发表时间：
2010-01
影响因子：
3.6
通讯作者：
Frankel G
中科院分区：
文献类型：
--
作者：
Crepin VF;Girard F;Schüller S;Phillips AD;Mousnier A;Frankel G
肠致病性大肠杆菌（EPEC）、肠出血性大肠杆菌（EPEC）的标志是附着和消失（A/E）损伤和肌动蛋白聚合。大肠杆菌（EHEC）和啮齿类柠檬酸杆菌（CR）感染，依赖于效应Tir。TirEPEC/CR Y 474/1的磷酸化导致Nck和神经Wiskott-Aldrich综合征蛋白（N-WASP）的募集以及培养细胞中的强肌动蛋白聚合。TirEPEC/CR还含有Asn-Pro-Tyr（NPY 454/1）基序，其触发弱肌动蛋白聚合。在EHEC中，NPY 458肌动蛋白聚合途径被TccP/EspFU扩增，TccP/EspFU通过IRSp 53和/或胰岛素受体酪氨酸激酶底物（IRTKS）募集到Tir。这里我们使用C。啮齿类动物研究体内不同的Tir信号通路。感染野生型C.啮齿动物IRTKS，而不是IRSp 53，被招募到细菌附着位点。用肠出血性大肠杆菌感染人回肠外植体后也观察到类似的结果。在TirCR中突变Y 471或Y 451分别消除Nck和IRTKS的募集，但不影响N-WASP的募集或A/E损伤形成。这表明，尽管它们在培养细胞中的肌动蛋白聚合中起着关键作用，但Tir：Nck和Tir：IRTKS途径对于体内N-WASP募集或A/E损伤形成不是必需的。重要的是，野生型C.啮齿类在混合感染期间胜过TIR酪氨酸突变体。这些结果使Tir：Nck和Tir：IRTKS通路与体内A/E病变形成分离，但赋予它们重要的体内作用。
Attaching and effacing (A/E) lesions and actin polymerization, the hallmark of enteropathogenic Escherichia coli (EPEC), enterohemorrhagic E. coli (EHEC) and Citrobacter rodentium (CR) infections, are dependent on the effector Tir. Phosphorylation of TirEPEC/CR Y474/1 leads to recruitment of Nck and neural Wiskott–Aldrich syndrome protein (N-WASP) and strong actin polymerization in cultured cells. TirEPEC/CR also contains an Asn-Pro-Tyr (NPY454/1) motif, which triggers weak actin polymerization. In EHEC the NPY458 actin polymerization pathway is amplified by TccP/EspFU, which is recruited to Tir via IRSp53 and/or insulin receptor tyrosine kinase substrate (IRTKS). Here we used C. rodentium to investigate the different Tir signalling pathways in vivo. Following infection with wild-type C. rodentium IRTKS, but not IRSp53, was recruited to the bacterial attachment sites. Similar results were seen after infection of human ileal explants with EHEC. Mutating Y471 or Y451 in TirCR abolished recruitment of Nck and IRTKS respectively, but did not affect recruitment of N-WASP or A/E lesion formation. This suggests that despite their crucial role in actin polymerization in cultured cells the Tir:Nck and Tir:IRTKS pathways are not essential for N-WASP recruitment or A/E lesion formation in vivo. Importantly, wild-type C. rodentium out-competed the tir tyrosine mutants during mixed infections. These results uncouple the Tir:Nck and Tir:IRTKS pathways from A/E lesion formation in vivo but assign them an important in vivo role.
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影响因子：
3.4
作者：
Garmendia, Junkal;Carlier, Marie-France;Frankel, Gad
通讯作者：
Frankel, Gad
影响因子：
3.6
作者：
Hartland, EL;Batchelor, M;Frankel, G
通讯作者：
Frankel, G
影响因子：
3.1
作者：
Girard, F;Batisson, I;Fairbrother, JM
通讯作者：
Fairbrother, JM
影响因子：
3.6
作者：
Deng, WY;Vallance, BA;Finlay, BB
通讯作者：
Finlay, BB
影响因子：
2.1
作者：
Girard, Francis;Frankel, Gad;La Ragione, Roberto M.
通讯作者：
La Ragione, Roberto M.