Reassessing the role of DotF in the Legionella pneumophila type IV secretion system.
Reassessing the role of DotF in the Legionella pneumophila type IV secretion system.
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DOI：
10.1371/journal.pone.0065529
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发表时间：
2013
期刊：
影响因子：
3.7
通讯作者：
Vogel JP
中科院分区：
文献类型：
--
作者：
Sutherland MC;Binder KA;Cualing PY;Vogel JP
嗜肺军团菌是一种严重肺炎的病原体，称为军团病，在原生动物宿主和人肺泡巨噬细胞中存活和复制。细胞内存活依赖于分泌过多的蛋白质效应物，其功能是形成复制泡，逃避内吞途径并破坏宿主免疫防御。这些因子的输出需要称为Dot/Icm的IV型分泌系统（T4 SS），其由27种蛋白质组成。这份报告的重点是DotF蛋白，这是以前假设有几个不同的功能，其中一个集中在结合点/Icm底物。在本报告中，我们检查了DotF是否作为Dot/Icm底物的T4 SS内膜受体。虽然我们能够概括先前发表的细菌双杂交DotF和几种底物之间的相互作用，相互作用不依赖于点/Icm底物的信号序列，如预测的底物：受体相互作用。此外，结合不需要DotF的胞质结构域，其预期参与识别细胞质中的底物。最后，dotF的失活并没有阻止L.嗜肺细胞或底物易位，两种表型依赖于T4 SS受体。这些数据强烈表明DotF不作为Dot/Icm底物的主要受体，因此可能在L.嗜肺菌Dot/Icm IV型分泌系统。
Legionella pneumophila, the causative agent of a severe pneumonia termed Legionnaires’ Disease, survives and replicates within both protozoan hosts and human alveolar macrophages. Intracellular survival is dependent upon secretion of a plethora of protein effectors that function to form a replicative vacuole, evade the endocytic pathway and subvert host immune defenses. Export of these factors requires a type IV secretion system (T4SS) called Dot/Icm that is composed of twenty-seven proteins. This report focuses on the DotF protein, which was previously postulated to have several different functions, one of which centered on binding Dot/Icm substrates. In this report, we examined if DotF functions as the T4SS inner membrane receptor for Dot/Icm substrates. Although we were able to recapitulate the previously published bacterial two-hybrid interaction between DotF and several substrates, the interaction was not dependent on the Dot/Icm substrates’ signal sequences as predicted for a substrate:receptor interaction. In addition, binding did not require the cytoplasmic domain of DotF, which was anticipated to be involved in recognizing substrates in the cytoplasm. Finally, inactivation of dotF did not abolish intracellular growth of L. pneumophila or translocation of substrates, two phenotypes dependent on the T4SS receptor. These data strongly suggest that DotF does not act as the major receptor for Dot/Icm substrates and therefore likely performs an accessory function within the core-transmembrane subcomplex of the L. pneumophila Dot/Icm type IV secretion system.
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影响因子：
3.4
作者：
Heidtman M;Chen EJ;Moy MY;Isberg RR
通讯作者：
Isberg RR
影响因子：
15.9
作者：
Al-Quadan, Tasneem;Price, Christopher T.;Abu Kwaik, Yousef
通讯作者：
Abu Kwaik, Yousef
影响因子：
2.8
作者：
Albers, U;Reus, K;Hilbi, H
通讯作者：
Hilbi, H
影响因子：
3.6
作者：
Bardill, JP;Miller, JL;Vogel, JP
通讯作者：
Vogel, JP
DOI：
10.1038/nrmicro2218
发表时间：
2009-10
期刊：
Nature reviews. Microbiology
影响因子：
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作者：
通讯作者：
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