A Pseudomonas T6SS effector recruits PQS-containing outer membrane vesicles for iron acquisition.
A Pseudomonas T6SS effector recruits PQS-containing outer membrane vesicles for iron acquisition.
复制标题
假单胞菌 T6SS 效应子招募含有 PQS 的外膜囊泡来获取铁
DOI：
10.1038/ncomms14888
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发表时间：
2017-03-28
影响因子：
16.6
通讯作者：
Shen X
中科院分区：
文献类型：
--
作者：
Lin J;Zhang W;Cheng J;Yang X;Zhu K;Wang Y;Wei G;Qian PY;Luo ZQ;Shen X
宿主蛋白质的铁隔离有助于抵御细菌病原体，细菌病原体需要铁来进行代谢和毒力。铜绿假单胞菌突变体缺乏所有三种已知的铁获取系统，但在含铁螯合剂的培养基中仍能生长，这表明存在涉及铁摄取的其他途径。在这里，我们筛选了在缺铁培养基中生长缺陷的铜绿假单胞菌突变体，发现靠近VI型分泌系统H3 （H3- t6ss）的基因PA2374与已知的铁获取系统协同作用。PA2374（我们已将其重新命名为TseF）似乎由H3-T6SS分泌，并通过与铁结合假单胞菌喹诺酮信号（PQS）（一种细胞-细胞信号化合物）直接相互作用而被纳入外膜囊泡（OMVs）。TseF通过结合Fe(III)-pyochelin受体FptA和孔蛋白OprF，促进omv相关铁向细菌细胞的传递。我们的研究结果揭示了P. aeruginosa中VI型分泌，细胞-细胞信号传导和典型铁载体受体获取铁之间的联系。
Iron sequestration by host proteins contributes to the defence against bacterial pathogens, which need iron for their metabolism and virulence. A Pseudomonas aeruginosa mutant lacking all three known iron acquisition systems retains the ability to grow in media containing iron chelators, suggesting the presence of additional pathways involved in iron uptake. Here we screen P. aeruginosa mutants defective in growth in iron-depleted media and find that gene PA2374, proximal to the type VI secretion system H3 (H3-T6SS), functions synergistically with known iron acquisition systems. PA2374 (which we have renamed TseF) appears to be secreted by H3-T6SS and is incorporated into outer membrane vesicles (OMVs) by directly interacting with the iron-binding Pseudomonas quinolone signal (PQS), a cell–cell signalling compound. TseF facilitates the delivery of OMV-associated iron to bacterial cells by engaging the Fe(III)-pyochelin receptor FptA and the porin OprF. Our results reveal links between type VI secretion, cell–cell signalling and classic siderophore receptors for iron acquisition in P. aeruginosa.