Lipoprotein transport from the inner to the outer membrane, carried out by the Lol machinery, is essential for the biogenesis of the Gram-negative cell envelope and, consequently, for bacterial viability. Recently, small molecule inhibitors of the Lol system in Escherichia coli have been identified and shown to inhibit the growth of this organism by interfering with the function of the LolCDE complex. Analysis of the transcriptome of E. coli treated with one such molecule (compound 2) revealed that a number of envelope stress response pathways were induced in response to LolCDE inhibition. However, Pseudomonas aeruginosa is refractory to inhibition by the same small molecule, but we could demonstrate that E. coli lolCDE could be substituted for the P. aeruginosa orthologues, where it functions in the correct transport of Pseudomonas lipoproteins, and the cells are inhibited by the more potent compound 2A. In the present study, we took advantage of the functionality of E. coli LolCDE in P. aeruginosa and determined the P. aeruginosa transcriptional response to LolCDE inhibition by compound 2A. We identified key genes that responded to LolCDE inhibition and also demonstrated that the same genes appeared to be affected by genetic depletion of the native P. aeruginosa LolCDE proteins. Several of the major changes were in an upregulated cluster of genes that encode determinants of alginate biosynthesis and transport, and the levels of alginate were found to be increased either by treatment with the small molecule inhibitor or upon depletion of native LolCDE. Finally, we tested several antibiotics with differing mechanisms of action to identify potential specific reporter genes for the further development of compounds that would inhibit the native P. aeruginosa Lol system.

中文翻译：

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铜绿假单胞菌对小分子抑制剂抑制脂蛋白转运的转录反应。

Lol机器将脂蛋白从内膜转运到外膜，对于革兰氏阴性细胞包膜的生物合成至关重要，因此对于细菌生存力也至关重要。最近，已经鉴定出大肠杆菌中的Lol系统的小分子抑制剂，并显示出通过干扰LolCDE复合物的功能来抑制该生物体的生长。对用一种这样的分子（化合物2）处理的大肠杆菌的转录组的分析显示，响应LolCDE抑制，诱导了许多包膜应激反应途径。但是，铜绿假单胞菌对相同的小分子具有抑制作用，但是我们可以证明大肠杆菌 lolCDE可以用铜绿假单胞菌的直系同源基因代替，它在假单胞菌脂蛋白的正确运输中起作用，并且细胞被更有效的化合物2A抑制。在本研究中，我们利用了铜绿假单胞菌中大肠杆菌LolCDE的功能，并确定了铜绿假单胞菌对化合物2A抑制LolCDE的转录反应。我们确定了响应LolCDE抑制的关键基因，并且还证明了相同的基因似乎受天然铜绿假单胞菌的遗传消耗影响。LolCDE蛋白。几个主要变化是在编码藻酸盐生物合成和运输决定因子的基因上调簇中，发现藻酸盐水平通过小分子抑制剂治疗或天然LolCDE耗尽而增加。最后，我们测试了几种具有不同作用机制的抗生素，以确定潜在的特定报道基因，以进一步抑制化合物抑制天然铜绿假单胞菌Lol系统。