Leaphart Adam B, Thompson Dorothea K, Huang Katherine, Alm Eric, Wan Xiu-Feng, Arkin Adam, Brown Steven D, Wu Liyou, Yan Tingfen, Liu Xueduan, Wickham Gene S, Zhou Jizhong
Environmental Sciences Division, Oak Ridge National Laboratory, Tennessee 37831, USA.
J Bacteriol. 2006 Feb;188(4):1633-42. doi: 10.1128/JB.188.4.1633-1642.2006.
The molecular response of Shewanella oneidensis MR-1 to variations in extracellular pH was investigated based on genomewide gene expression profiling. Microarray analysis revealed that cells elicited both general and specific transcriptome responses when challenged with environmental acid (pH 4) or base (pH 10) conditions over a 60-min period. Global responses included the differential expression of genes functionally linked to amino acid metabolism, transcriptional regulation and signal transduction, transport, cell membrane structure, and oxidative stress protection. Response to acid stress included the elevated expression of genes encoding glycogen biosynthetic enzymes, phosphate transporters, and the RNA polymerase sigma-38 factor (rpoS), whereas the molecular response to alkaline pH was characterized by upregulation of nhaA and nhaR, which are predicted to encode an Na+/H+ antiporter and transcriptional activator, respectively, as well as sulfate transport and sulfur metabolism genes. Collectively, these results suggest that S. oneidensis modulates multiple transporters, cell envelope components, and pathways of amino acid consumption and central intermediary metabolism as part of its transcriptome response to changing external pH conditions.
基于全基因组基因表达谱,研究了嗜铁钩端螺旋菌MR-1对细胞外pH变化的分子响应。微阵列分析显示,当细胞在60分钟内受到环境酸性(pH 4)或碱性(pH 10)条件挑战时,会引发一般和特定的转录组反应。整体反应包括与氨基酸代谢、转录调控和信号转导、转运、细胞膜结构以及氧化应激保护功能相关的基因差异表达。对酸胁迫的反应包括编码糖原生物合成酶、磷酸盐转运蛋白和RNA聚合酶σ-38因子(rpoS)的基因表达升高,而对碱性pH的分子反应特征是nhaA和nhaR上调,预计它们分别编码Na+/H+反向转运蛋白和转录激活因子,以及硫酸盐转运和硫代谢基因。总的来说,这些结果表明,嗜铁钩端螺旋菌会调节多种转运蛋白、细胞包膜成分以及氨基酸消耗途径和中心中间代谢,作为其转录组对外部pH条件变化反应的一部分。