DksA-Dependent Transcriptional Regulation in Salmonella Experiencing Nitrosative Stress

摘要: Redox-based signaling is fundamental to the capacity of bacteria sense, and respond to, nitrosative oxidative stress encountered in natural host environments. The conserved RNA polymerase regulatory protein DksA a thiol-based sensor reactive nitrogen oxygen species. DksA-dependent transcriptional control promotes antinitrosative antioxidative defenses that contribute Salmonella pathogenesis. specific adaptive changes mediated by response species, however, have not been elucidated. Herein, we characterize gene expression enterica experiencing stress. Genome-wide analysis wild-type ΔdksA exposed nitric oxide ((•)NO) donor DETA NONOate demonstrated (•)NO- 427 target genes. Transcriptional centered primarily on genes encoding aspects cellular metabolism. Several antioxidants oxidoreductases important redox buffering, (•)NO detoxification, damage repair were also observed be up-regulated an manner. Compared bacteria, (•)NO-treated exhibited de-repression components iron homeostasis failed activate sulfur assimilation cysteine biosynthetic operons. As integral efficient defense programs, further examined redox-responsive biosynthesis DksA. These investigations revealed activation comprising occurs hydrogen peroxide, dependent upon redox-sensing zinc finger motif DksA, requires regulator CysB. Our observations demonstrate mediates global adaptation provide unique insight into novel mechanism which controlled