YchJ Transcription Factor Regulates Salmonella Defense Against Macrophage Oxidative Stress
Researchers have identified YchJ, a previously uncharacterized protein, as a crucial ROS-sensing transcription factor in Salmonella. Published in Nature Communications, the study reveals that YchJ operates independently of the canonical OxyR system to protect the pathogen from oxidative attacks by host macrophages. Upon exposure to reactive oxygen species (ROS), YchJ undergoes reversible dimerization via an intermolecular disulfide bond. This structural change allows it to bind the rssB promoter, repressing rssB transcription. Consequently, this leads to the stabilization of RpoS and the upregulation of key antioxidant enzymes, such as SodC and KatE. Deletion of the ychJ gene significantly impaired bacterial survival under hydrogen peroxide stress and within macrophages. Dual-transcriptome analysis confirmed that YchJ not only activates bacterial antioxidant defenses but also disrupts host pathways during infection. These findings elucidate a novel redox-sensing mechanism essential for Salmonella virulence, expanding the understanding of stress-response regulation in pathogenic bacteria and highlighting potential targets for therapeutic intervention against bacterial infections.
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YchJ Transcription Factor Regulates Salmonella Defense Against Macrophage Oxidative Stress
Researchers have identified YchJ, a previously uncharacterized protein, as a crucial ROS-sensing transcription factor in Salmonella. Published in Nature Communications, the study reveals that YchJ operates independently of the canonical OxyR system to protect the pathogen from oxidative attacks by host macrophages. Upon exposure to reactive oxygen species (ROS), YchJ undergoes reversible dimerization via an intermolecular disulfide bond. This structural change allows it to bind the rssB promoter, repressing rssB transcription. Consequently, this leads to the stabilization of RpoS and the upregulation of key antioxidant enzymes, such as SodC and KatE. Deletion of the ychJ gene significantly impaired bacterial survival under hydrogen peroxide stress and within macrophages. Dual-transcriptome analysis confirmed that YchJ not only activates bacterial antioxidant defenses but also disrupts host pathways during infection. These findings elucidate a novel redox-sensing mechanism essential for Salmonella virulence, expanding the understanding of stress-response regulation in pathogenic bacteria and highlighting potential targets for therapeutic intervention against bacterial infections.
Nature Communications