The heterologous siderophores ferrioxamine B and ferrichrome activate signaling pathways in Pseudomonas aeruginosa
The heterologous siderophores ferrioxamine B and ferrichrome activate signaling pathways in Pseudomonas aeruginosa
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DOI：
10.1128/jb.188.5.1882-1891.2006
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发表时间：
2006-03-01
影响因子：
3.2
通讯作者：
Bitter, W
中科院分区：
文献类型：
--
作者：
Llamas, MA;Sparrius, M;Bitter, W
铜绿假单胞菌在铁限制的条件下分泌两种铁载体，即焦磷和绿球蛋白。这些铁载体在细胞表面被特定的外膜受体识别，也称为TonB依赖受体。此外，这种细菌还能够整合许多细菌或真菌来源的异源铁载体，这体现在存在另外32个编码假定的TonB依赖受体的基因。在这项工作中，我们使用蛋白质组学的方法来确定铜绿假单胞菌TonB依赖受体的诱导条件。总共有11个受体可以在不同的条件下被识别。其中两种只在羟甲酸铁载体、铁胺B和铁铬存在的情况下产生。它们的合成调节既受铁的影响，也受同源铁载体的影响。对铜绿假单胞菌基因组的分析表明，这两个受体基因都位于编码胞外功能西格玛因子和跨膜传感器的调节点附近。这个假定的调控基因参与了铁胺B和铁色素受体的特异性诱导。这些结果表明，铜绿假单胞菌已经进化出多种特定的调节系统，以允许调节TonB依赖的受体。
Pseudomonas aeruginosa secretes two siderophores, pyoverdine and pyochelin, under iron-limiting conditions. These siderophores are recognized at the cell surface by specific outer membrane receptors, also known as TonB-dependent receptors. In addition, this bacterium is also able to incorporate many heterologous siderophores of bacterial or fungal origin, which is reflected by the presence of 32 additional genes encoding putative TonB-dependent receptors. In this work, we have used a proteomic approach to identify the inducing conditions for P. aeruginosa TonB-dependent receptors. In total, 11 of these receptors could be discerned under various conditions. Two of them are only produced in the presence of the hydroxamate siderophores ferrioxamine B and ferrichrome. Regulation of their synthesis is affected by both iron and the presence of a cognate siderophore. Analysis of the P. aeruginosa genome showed that both receptor genes are located next to a regulatory locus encoding an extracytoplasmic function sigma factor and a transmembrane sensor. The involvement of this putative regulatory locus in the specific induction of the ferrioxamine B and ferrichrome receptors has been demonstrated. These results show that P. aeruginosa has evolved multiple specific regulatory systems to allow the regulation of TonB-dependent receptors.