Identification of the iron-responsive genes of Neisseria gonorrhoeae by microarray analysis in defined medium
Identification of the iron-responsive genes of Neisseria gonorrhoeae by microarray analysis in defined medium
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DOI：
10.1128/jb.187.14.4865-4874.2005
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发表时间：
2005-07-01
影响因子：
3.2
通讯作者：
Dyer, DW
中科院分区：
文献类型：
--
作者：
Ducey, TF;Carson, MB;Dyer, DW
为了确保生存，大多数细菌必须获得铁，这是一种被哺乳动物宿主隔离的资源。因此，致病细菌已经进化出复杂的系统来感知铁限制并适当地调节基因表达。我们使用了泛奈瑟菌微阵列来检查淋病奈瑟菌中响应于限定培养基中的铁可用性的基因。总的来说，203个基因的表达不同，109上调和94下调铁剥夺。在充满铁的培养基中，细菌快速生长所必需的基因优先表达，而铁运输功能，主要是未知功能的基因，在低铁培养基中表达。在FA1090基因组中编码的具有未知配体特异性的TonB依赖性蛋白中，有三种蛋白的表达不受铁可用性的控制，这表明这些受体可能不是含铁配体的高亲和力转运蛋白。大约30%的铁调控的操纵子似乎是直接控制的毛皮。我们的数据表明，一个监管级联反应，毛皮间接控制基因表达的影响三个二级监管机构的转录。我们的数据还表明，第二个MerR样调节器可能直接响应铁的可用性和控制转录独立的毛皮蛋白。我们的数据与最近发表的脑膜炎奈瑟氏球菌的数据比较显示，只有一小部分基因被发现在这些密切相关的病原体中受到类似的调控，而大量的基因在铁饥饿期间被解除抑制，这是每个生物体所独有的。
To ensure survival, most bacteria must acquire iron, a resource that is sequestered by mammalian hosts. Pathogenic bacteria have therefore evolved intricate systems to sense iron limitation and regulate gene expression appropriately. We used a pan-Neisseria microarray to examine genes regulated in Neisseria gonorrhoeae in response to iron availability in defined medium. Overall, 203 genes varied in expression, 109 up-regulated and 94 down-regulated by iron deprivation. In iron-replete medium, genes essential to rapid bacterial growth were preferentially expressed, while iron transport functions, and predominantly genes of unknown function, were expressed in low-iron medium. Of those TonB-dependent proteins encoded in the FA1090 genome with unknown ligand specificity, expression of three was not controlled by iron availability, suggesting that these receptors may not be high-affinity transporters for iron-containing ligands. Approximately 30% of the operons regulated by iron appeared to be directly under control of Fur. Our data suggest a regulatory cascade where Fur indirectly controls gene expression by affecting the transcription of three secondary regulators. Our data also suggest that a second MerR-like regulator may be directly responding to iron availability and controlling transcription independent of the Fur protein. Comparison of our data with those recently published for Neisseria meningitidis revealed that only a small portion of genes were found to be similarly regulated in these closely related pathogens, while a large number of genes derepressed during iron starvation were unique to each organism.