Transcriptional Responses of Escherichia coli to a Small-Molecule Inhibitor of LolCDE, an Essential Component of the Lipoprotein Transport Pathway.
Transcriptional Responses of Escherichia coli to a Small-Molecule Inhibitor of LolCDE, an Essential Component of the Lipoprotein Transport Pathway.
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DOI：
10.1128/jb.00502-16
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发表时间：
2016-12-01
影响因子：
3.2
通讯作者：
Lory S
中科院分区：
文献类型：
--
作者：
Lorenz C;Dougherty TJ;Lory S
在革兰氏阴性细菌中，由LolABCDE成分组成的专用机制将脂蛋白靶向到外膜。我们使用先前鉴定的大肠杆菌LolCDE复合物的小分子抑制剂来评估干扰脂蛋白运输的全球转录后果。将大肠杆菌暴露于浓度为最小和显著的生长抑制的LolCDE抑制剂中，然后进行转录组测序，发现与未处理的细胞相比，一小组基因的转录水平降低，而更大的一组基因的mRNA水平增加了10至100倍。大多数mRNA浓度降低的基因是鞭毛组装途径的一部分，该途径含有必需的脂蛋白成分。大多数转录水平升高的基因编码的蛋白质参与了选定的细胞应激途径。这些基因中有许多与外膜脂蛋白错定位引起的包膜应激反应有关。虽然一些rna被诱导的基因先前已被证明与抗生素对细胞包膜的一般扰动有关，但一小部分基因仅受LolCDE抑制的影响。这项工作的发现表明，Lol系统功能的效率可能与特定的监测系统相耦合，这可以用于开发适合用于筛选其他脂蛋白运输抑制剂的报告构建物。抑制脂蛋白运输途径导致大肠杆菌死亡和随后的裂解。观察到与一些质周和包膜应激反应相关的基因子集的RNA水平的早期显著变化。总之，这些发现表明，这一关键途径的破坏可能对平衡的外膜合成产生严重影响，足以影响生存能力。
In Gram-negative bacteria, a dedicated machinery consisting of LolABCDE components targets lipoproteins to the outer membrane. We used a previously identified small-molecule inhibitor of the LolCDE complex of Escherichia coli to assess the global transcriptional consequences of interference with lipoprotein transport. Exposure of E. coli to the LolCDE inhibitor at concentrations leading to minimal and significant growth inhibition, followed by transcriptome sequencing, identified a small group of genes whose transcript levels were decreased and a larger group whose mRNA levels increased 10- to 100-fold compared to those of untreated cells. The majority of the genes whose mRNA concentrations were reduced were part of the flagellar assembly pathway, which contains an essential lipoprotein component. Most of the genes whose transcript levels were elevated encode proteins involved in selected cell stress pathways. Many of these genes are involved with envelope stress responses induced by the mislocalization of outer membrane lipoproteins. Although several of the genes whose RNAs were induced have previously been shown to be associated with the general perturbation of the cell envelope by antibiotics, a small subset was affected only by LolCDE inhibition. Findings from this work suggest that the efficiency of the Lol system function may be coupled to a specific monitoring system, which could be exploited in the development of reporter constructs suitable for use for screening for additional inhibitors of lipoprotein trafficking. IMPORTANCE Inhibition of the lipoprotein transport pathway leads to E. coli death and subsequent lysis. Early significant changes in the levels of RNA for a subset of genes identified to be associated with some periplasmic and envelope stress responses were observed. Together these findings suggest that disruption of this key pathway can have a severe impact on balanced outer membrane synthesis sufficient to affect viability.