Shi Liang, Ansong Charles, Smallwood Heather, Rommereim Leah, McDermott Jason E, Brewer Heather M, Norbeck Angela D, Taylor Ronald C, Gustin Jean K, Heffron Fred, Smith Richard D, Adkins Joshua N
Pacific Northwest National Laboratory, Richland, Washington 99352.
J Proteomics Bioinform. 2009;2:388-397. doi: 10.4172/jpb.1000099.
To determine the impact of a low Mg(2+)/pH defined growth medium (MgM) on the proteome of Salmonella enterica serotype Typhimurium, we cultured S. Typhimurium cells in the medium under two different conditions termed MgM Shock and MgM Dilution and then comparatively analyzed the bacterial cells harvested from these conditions by a global proteomic approach. Proteomic results showed that MgM Shock and MgM Dilution differentially affected the S. Typhimurium proteome. MgM Shock induced a group of proteins whose induction usually occurred at low O(2) level, while MgM Dilution induced those related to the type III secretion system (T3SS) of Salmonella Pathogenicity Island 2 (SPI2) and those involved in thiamine or biotin biosynthesis. The metabolic state of the S. Typhimurium cells grown under MgM Shock condition also differed significantly from that under MgM Dilution condition. Western blot analysis not only confirmed the proteomic results, but also showed that the abundances of SPI2-T3SS proteins SsaQ and SseE and biotin biosynthesis proteins BioB and BioD increased after S. Typhimurium infection of RAW 264.7 macrophages. Deletion of the gene encoding BioB reduced the bacterial ability to replicate inside the macrophages, suggesting a biotin-limited environment encountered by S. Typhimurium within RAW 264.7 macrophages.
为了确定低镁离子/低pH值限定生长培养基（MgM）对鼠伤寒沙门氏菌蛋白质组的影响，我们在两种不同条件下（分别称为MgM冲击和MgM稀释）于该培养基中培养鼠伤寒沙门氏菌细胞，然后通过一种全面的蛋白质组学方法对从这些条件下收获的细菌细胞进行比较分析。蛋白质组学结果表明，MgM冲击和MgM稀释对鼠伤寒沙门氏菌蛋白质组的影响不同。MgM冲击诱导了一组通常在低氧水平下表达的蛋白质，而MgM稀释诱导了与沙门氏菌致病岛2（SPI2）的III型分泌系统（T3SS）相关的蛋白质以及参与硫胺素或生物素生物合成的蛋白质。在MgM冲击条件下生长的鼠伤寒沙门氏菌细胞的代谢状态也与MgM稀释条件下的显著不同。蛋白质免疫印迹分析不仅证实了蛋白质组学结果，还表明在RAW 264.7巨噬细胞被鼠伤寒沙门氏菌感染后，SPI2-T3SS蛋白SsaQ和SseE以及生物素生物合成蛋白BioB和BioD的丰度增加。编码BioB的基因缺失降低了细菌在巨噬细胞内复制的能力，这表明鼠伤寒沙门氏菌在RAW 264.7巨噬细胞内遇到了生物素受限的环境。
