Mukhopadhyay Partha, Zheng Ming, Bedzyk Laura A, LaRossa Robert A, Storz Gisela
Cell Biology and Metabolism Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
Proc Natl Acad Sci U S A. 2004 Jan 20;101(3):745-50. doi: 10.1073/pnas.0307741100. Epub 2004 Jan 12.
We examined the genomewide transcriptional responses of Escherichia coli treated with nitrosylated glutathione or the nitric oxide (NO)-generator acidified sodium nitrite (NaNO(2)) during aerobic growth. These assays showed that NorR, a homolog of NO-responsive transcription factors in Ralstonia eutrophus, and Fur, the global repressor of ferric ion uptake, are major regulators of the response to reactive nitrogen species. In contrast, SoxR and OxyR, regulators of the E. coli defenses against superoxide-generating compounds and hydrogen peroxide, respectively, have minor roles. Moreover, additional regulators of the E. coli response to reactive nitrogen species remain to be identified because several of the induced genes were regulated normally in norR, fur, soxRS, and oxyR mutant strains. We propose that the E. coli transcriptional response to reactive nitrogen species is a composite response mediated by the modification of multiple transcription factors containing iron or redox-active cysteines, some specifically designed to sense NO and its derivatives and others that are collaterally activated by the reactive nitrogen species.
我们研究了在有氧生长期间，经亚硝基化谷胱甘肽或一氧化氮（NO）生成剂酸化亚硝酸钠（NaNO₂）处理的大肠杆菌的全基因组转录反应。这些分析表明，嗜铁假单胞菌中NO响应转录因子的同源物NorR以及铁离子摄取的全局阻遏物Fur是对活性氮物种反应的主要调节因子。相比之下，分别作为大肠杆菌抵御产生超氧化物的化合物和过氧化氢的防御调节因子的SoxR和OxyR作用较小。此外，由于一些诱导基因在norR、fur、soxRS和oxyR突变菌株中正常调控，因此大肠杆菌对活性氮物种反应的其他调节因子仍有待确定。我们提出，大肠杆菌对活性氮物种的转录反应是一种复合反应，由含有铁或氧化还原活性半胱氨酸的多种转录因子的修饰介导，其中一些专门设计用于感知NO及其衍生物，而其他因子则被活性氮物种间接激活。
