Iron and Pseudomonas aeruginosa biofilm formation
Iron and Pseudomonas aeruginosa biofilm formation
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DOI：
10.1073/pnas.0504266102
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发表时间：
2005-08-02
影响因子：
11.1
通讯作者：
Greenberg, EP
中科院分区：
文献类型：
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作者：
Banin, E;Vasil, ML;Greenberg, EP
铁在铜绿假单胞菌生物膜发育中起信号作用。我们研究了已知和推测的铁获取信号基因突变对生物膜形态的影响。在铁充足的培养基中，突变体不能通过高亲和力的pyoverdine铁获取系统获得铁，形成类似于亲本在低铁条件下形成的薄生物膜。如果为pyoverdine突变体提供不同铁获取系统的铁源，则正常的生物膜发育发生。这使我们能够确定铁摄取基因簇，可能在运输中服务于柠檬酸铁和铁胺。我们认为铜绿假单胞菌生物膜发育的功能性铁信号是螯合铁的主动运输或体内铁的水平。如果信号是内部铁水平，那么一个可能涉及铁信号的因子是胞质铁摄取调节蛋白，Fur，它控制铁反应基因的表达。为了支持Fur的参与，我们发现低铁的Fur突变体能够比亲本组织成更成熟的生物膜。两种已知的由毛皮控制的小调控rna （PrrF1和F2）似乎不介导铁对生物膜发育的控制。这一信息建立了铁控制铜绿假单胞菌生物膜形成的机制基础。
Iron serves as a signal in Pseudomonas aeruginosa biofilm development. We examined the influence of mutations in known and putative iron acquisition-signaling genes on biofilm morphology. In iron-sufficient medium, mutants that cannot obtain iron through the high-affinity pyoverdine iron acquisition system form thin biofilms similar to those formed by the parent under low iron conditions. If an iron source for a different iron acquisition system is provided to a pyoverdine mutant, normal biofilm development occurs. This enabled us to identify iron uptake gene clusters that likely serve in transport of ferric citrate and ferrioxamine. We suggest that the functional iron signal for P. aeruginosa biofilm development is active transport of chelated iron or the level of internal iron. If the signal is internal iron levels, then a factor likely to be involved in iron signaling is the cytoplasmic ferric uptake regulator protein, Fur, which controls expression of iron-responsive genes. In support of a Fur involvement, we found that with low iron a Fur mutant was able to organize into more mature biofilms than was the parent. The two known Fur-controlled small regulatory RNAs (PrrF1 and F2) do not appear to mediate iron control of biofilm development. This information establishes a mechanistic basis for iron control of P. aeruginosa biofilm formation.