Proteomic response of Streptococcus pneumoniae to iron limitation
Proteomic response of Streptococcus pneumoniae to iron limitation
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DOI：
10.1016/j.ijmm.2018.02.001
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发表时间：
2018-08-01
影响因子：
4.1
通讯作者：
Becher, Doerte
中科院分区：
文献类型：
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作者：
Hoyer, Juliane;Bartel, Juergen;Becher, Doerte
铁是一种必需的微量元素，参与细菌生活方式的各种关键代谢途径。人体体内的铁含量极为有限。因此，细菌从环境中获取铁的能力对于成功感染至关重要。肺炎链球菌（肺炎球菌）是一种定植于人类呼吸道的无症状人类病原体，但也可引起各种局部和侵袭性感染。因此，为了生存和增殖，肺炎球菌必须使其代谢和毒力因子库适应不同的宿主区室。在这项研究中，在蛋白质组水平上研究了肺炎链球菌对铁限制作为感染相关病症的反应。通过在模拟不同生理特征的两种不同介质中应用铁螯合剂 2,2'-联吡啶 (RIP) 来诱导铁限制。在这些条件下，分析了初始铁浓度对有限铁可用性的肺炎球菌蛋白表达的影响。有趣的是，这两个铁限制实验之间的一个主要区别是参与肺炎球菌发病机制的蛋白质的调节。在缺铁培养基中，该组的一些蛋白质被下调，而这些蛋白质在富铁培养基中被上调。然而，两种环境中的铁限制都会导致铁吸收蛋白 PiuA 的强烈上调和非血红素含铁铁蛋白 Dpr 的显着下调。结果表明，肺炎球菌蛋白质组对铁限制的反应强烈依赖于培养基或环境中的初始铁浓度。
Iron is an essential trace element and involved in various key metabolic pathways in bacterial lifestyle. Within the human host, iron is extremely limited. Hence, the ability of bacteria to acquire iron from the environment is critical for a successful infection. Streptococcus pneumoniae (the pneumococcus) is a human pathobiont colonizing symptomless the human respiratory tract, but can also cause various local and invasive infections. To survive and proliferate pneumococci have therefore to adapt their metabolism and virulence factor repertoire to different host compartments. In this study, the response of S. pneumoniae to iron limitation as infection-relevant condition was investigated on the proteome level. The iron limitation was induced by application of the iron chelator 2,2'-bipyridine (RIP) in two different media mimicking different physiological traits. Under these conditions, the influence of the initial iron concentration on pneumococcal protein expression in response to limited iron availability was analyzed. Interestingly, one major difference between these two iron limitation experiments is the regulation of proteins involved in pneumococcal pathogenesis. In iron-poor medium several proteins of this group were downregulated whereas these proteins are upregulated in iron-rich medium. However, iron limitation in both environments led to a strong upregulation of the iron uptake protein PiuA and the significant downregulation of the non-heme iron-containing ferritin Dpr. Based on the results, it is shown that the pneumococcal proteome response to iron limitation is strongly dependent on the initial iron concentration in the medium or the environment.