Response of Porphyromonas gingivalis to Heme Limitation in Continuous Culture
Response of Porphyromonas gingivalis to Heme Limitation in Continuous Culture
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DOI：
10.1128/jb.01270-08
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发表时间：
2009-02-01
影响因子：
3.2
通讯作者：
Reynolds, Eric C.
中科院分区：
文献类型：
--
作者：
Dashper, Stuart G.;Ang, Ching-Seng;Reynolds, Eric C.
牙龈卟啉单胞菌是一种厌氧、解糖、革兰氏阴性细菌，对铁和原卟啉 IX 都有必需的需求，它优先以血红素的形式获得铁和原卟啉 IX。使用稳定同位素标记策略和质谱的大规模定量蛋白质组学分析，以及使用定制 DNA 微阵列的转录组学分析相结合，用于鉴定牙龈卟啉单胞菌 W50 蛋白和转录物丰度在从血红素过量到血红素有限的连续培养变化时的变化。该方法鉴定了 160 个基因和 70 个蛋白质，这些基因和蛋白质受血红素可用性的差异调节，转录组和蛋白质组数据之间具有广泛的一致性。在血红素限制的情况下观察到天冬氨酸和谷氨酸分解代谢途径的酶丰度发生变化，这反映在培养液的有机酸最终产物水平中。这些结果表明，在血红素限制下，从节能无氧呼吸到效率较低的过程的转变。血红素限制还导致蛋白质 PG1374 丰度增加，我们通过插入失活证明该蛋白质在上皮细胞侵袭中发挥作用。与宿主细胞的侵袭、氧化应激反应、铁/血红素转运和细菌毒力相关的大量转录物/蛋白质的丰度表明牙龈卟啉单胞菌对血红素可用性有广泛的反应。
Porphyromonas gingivalis is an anaerobic, asaccharolytic, gram-negative bacterium that has essential requirements for both iron and protoporphyrin IX, which it preferentially obtains as heme. A combination of large-scale quantitative proteomic analysis using stable isotope labeling strategies and mass spectrometry, together with transcriptomic analysis using custom-made DNA microarrays, was used to identify changes in P. gingivalis W50 protein and transcript abundances on changing from heme-excess to heme-limited continuous culture. This approach identified 160 genes and 70 proteins that were differentially regulated by heme availability, with broad agreement between the transcriptomic and proteomic data. A change in abundance of the enzymes of the aspartate and glutamate catabolic pathways was observed with heme limitation, which was reflected in organic acid end product levels of the culture fluid. These results demonstrate a shift from an energy-efficient anaerobic respiration to a less efficient process upon heme limitation. Heme limitation also resulted in an increase in abundance of a protein, PG1374, which we have demonstrated, by insertional inactivation, to have a role in epithelial cell invasion. The greater abundance of a number of transcripts/ proteins linked to invasion of host cells, the oxidative stress response, iron/heme transport, and virulence of the bacterium indicates that there is a broad response of P. gingivalis to heme availability.