Effect of AHL-QS on protein expression in P. aeruginosa PAO1-UW

We found that several Pseudomonas aeruginosa strains accumulate N2O at higher cell densities. This is caused by quorum sensing (QS) and not regulated on the transcriptional level. To investigate whether this is a posttranscriptional or posttranslational effect we collected cells for proteomics measurements from P. aeruginosa PAO1-UW wild type (wt1-4)and a rhlI/lasI knockout mutant (dm 1-4)during the transition to denitrification. The mutant served as a AHL-QS negative control since it lacks the enzymes for the production of these specific signaling molecules. Comparing the expression of genes in the nos operon, which encode the structural and ancilliary proteins for N2O reduction, revealed that the restricted N2O redcution in the wild type is not caused by the downregulation of any of these genes, but that it is a posttranscriptional effect. Samples wt1-4 and dm1-4 were used for this comparison. Samples wt 5 and dm 5 were excluded due to poor quality. The text file was generated by analysis with Maxquant.研究发现，多株铜绿假单胞菌（Pseudomonas aeruginosa）在较高细胞密度下会积累N2O。该现象由群体感应（quorum sensing, QS）介导，且并非在转录层面受到调控。为探究该效应属于转录后还是翻译后调控，我们在反硝化作用过渡期，从铜绿假单胞菌PAO1-UW野生型菌株（wt1-4）以及rhlI/lasI基因敲除突变株（dm1-4）中收集细胞用于蛋白质组学检测。该突变株可作为酰基高丝氨酸内酯类群体感应（AHL-QS）的阴性对照，因其缺乏合成这类特异性信号分子所需的酶。对编码N2O还原相关结构蛋白与辅助蛋白的nos操纵子（nos operon）内基因的表达水平进行比较后发现，野生型菌株中受限的N2O还原作用并非由这些基因的表达下调所导致，而是一种转录后调控效应。本对比分析采用了wt1-4与dm1-4组样本，而wt5和dm5组样本因质量不佳被排除。本研究的文本文件通过MaxQuant软件分析生成。