Palma Marco, Worgall Stefan, Quadri Luis E N
Department of Microbiology and Immunology, Weill Medical College of Cornell University, 1300 York Avenue, Box 62 W-706, New York, New York 10021, USA.
Arch Microbiol. 2003 Nov;180(5):374-9. doi: 10.1007/s00203-003-0602-z. Epub 2003 Sep 26.
To successfully infect humans, Pseudomonas aeruginosa (Pa) must overcome the low iron availability in host tissues. A transcriptome comparison was carried out between iron-starved cells of Pa treated with iron and untreated controls. The present study is the first global analysis of the early transcriptional response of exponentially growing Pa to iron. Approximately 1.3% of the Pa genes displayed > or = 5.0-fold changes in mRNA levels in iron-treated cells. Treatment affected the mRNA levels of many genes required for iron acquisition as well as several genes with relevance to virulence previously known to be regulated by iron. More importantly, the analysis permitted identification of 107 Pa genes whose mRNA levels were not previously known to be affected by iron. These genes are good candidates for mutagenesis studies aimed at identifying novel functions relevant to iron metabolism in Pa. Some of these genes encode predicted siderophore receptors, iron transport systems, TonB-dependent receptors, regulatory proteins, and proteins relevant to virulence. Notably, 49 genes encode hypothetical or conserved hypothetical proteins of unknown function, suggesting that they are involved directly or indirectly in iron metabolism or metabolic adaptation to different iron-availability conditions.
为了成功感染人类，铜绿假单胞菌（Pa）必须克服宿主组织中铁可用性低的问题。对用铁处理的缺铁Pa细胞和未处理的对照细胞进行了转录组比较。本研究是对指数生长的Pa对铁的早期转录反应的首次全局分析。在铁处理的细胞中，约1.3%的Pa基因的mRNA水平出现了≥5.0倍的变化。处理影响了许多铁获取所需基因的mRNA水平，以及先前已知受铁调节的几个与毒力相关的基因。更重要的是，该分析鉴定出了107个Pa基因，其mRNA水平以前未知受铁影响。这些基因是诱变研究的良好候选对象，旨在鉴定与Pa中铁代谢相关的新功能。其中一些基因编码预测的铁载体受体、铁转运系统、依赖TonB的受体、调节蛋白以及与毒力相关的蛋白。值得注意的是，49个基因编码功能未知的假定或保守假定蛋白，这表明它们直接或间接参与铁代谢或对不同铁可用性条件的代谢适应。
