Control of Redox Balance by the Stringent Response Regulatory Protein Promotes Antioxidant Defenses of Salmonella

Henard, Calvin A.; Bourret, Travis J.; Song, Mi-Ryoung; Vázquez‐Torres, Andrés

doi:10.1074/jbc.m110.160960

Cited by 71 publications

(103 citation statements)

References 48 publications

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“…Additionally, Henard and colleagues have elegantly shown that DksA is critical for the resistance of S. Typhimurium to oxidative stress and reactive nitrogen species during the systemic phase in a murine model of typhoid-like disease (23,24). Collectively, these previously published reports and the results presented here illuminate DksA as a key virulence regulator in Salmonella, which is required both at the early colonization stage and later, during systemic infection, suggesting a role in both gastrointestinal and systemic disease manifestations.…”

Section: Fig 6 Ssupporting

confidence: 55%

“…Several studies have described a role for DksA in regulation of pathogenicity in different Gram-negative pathogens, including Vibrio cholerae (15), Pseudomonas aeruginosa (16), Shigella flexneri (17,18), enterohemorrhagic E. coli (19), Campylobacter jejuni (20), Erwinia amylovora (21), and Haemophilus ducreyi (22). In S. Typhimurium, DksA was found to be involved in bacterial defense against oxidative (23) and nitrosative (24) stress in vitro, and this phenotype has been suggested as a possible explanation for the attenuation of a S. Typhimurium dksA mutant in the mouse typhoid model (23)(24)(25).…”

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confidence: 99%

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The Stringent Response Regulator DksA Is Required for Salmonella enterica Serovar Typhimurium Growth in Minimal Medium, Motility, Biofilm Formation, and Intestinal Colonization

et al. 2016

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c Salmonella enterica serovar Typhimurium is a facultative intracellular human and animal bacterial pathogen posing a major threat to public health worldwide. Salmonella pathogenicity requires complex coordination of multiple physiological and virulence pathways. DksA is a conserved Gram-negative regulator that belongs to a distinct group of transcription factors that bind directly to the RNA polymerase secondary channel, potentiating the effect of the signaling molecule ppGpp during a stringent response. Here, we established that in S. Typhimurium, dksA is induced during the logarithmic phase and DksA is essential for growth in minimal defined medium and plays an important role in motility and biofilm formation. Furthermore, we determined that DksA positively regulates the Salmonella pathogenicity island 1 and motility-chemotaxis genes and is necessary for S. Typhimurium invasion of human epithelial cells and uptake by macrophages. In contrast, DksA was found to be dispensable for S. Typhimurium host cell adhesion. Finally, using the colitis mouse model, we found that dksA is spatially induced at the midcecum during the early stage of the infection and required for gastrointestinal colonization and systemic infection in vivo. Taken together, these data indicate that the ancestral stringent response regulator DksA coordinates various physiological and virulence S. Typhimurium programs and therefore is a key virulence regulator of Salmonella. Salmonella enterica is a facultative intracellular human and animal bacterial pathogen responsible for global pandemics of food-borne infections that pose a major threat to public health. This highly versatile pathogen can infect a broad range of hosts and causes different clinical outcomes, ranging from asymptomatic carriage to systemic life-threatening disease (1). The single species S. enterica includes more than 2,600 serovars that share high sequence similarity and are taxonomically classified into six subspecies (2). Estimations suggest that Salmonella causes 93.8 million human infections and 155,000 deaths annually worldwide (3). The majority of nontyphoidal Salmonella (NTS) infections in humans present as gastroenteritis; however, about 5% may be invasive and manifest as bacteremia or other extraintestinal infections (4). Many of the NTS serovars are capable of colonizing the intestines of livestock with potential risk of contaminating the food chain, and therefore, salmonellosis is often associated with animal products and produce (5). One of the most common serovars worldwide is S. enterica serovar Typhimurium, ranking first in prevalence in North America and Oceania (6).Salmonella intestinal colonization is a complex phenotype essential for establishing disease. Salmonella colonization requires synchronized function of both conserved and host-specific colonization factors such as fimbrial adhesins, invasion factors (e.g., SiiE, MisL, and ShdA) and genes encoded within Salmonella pathogenicity island 1 (SPI-1) and SPI-2 (reviewed in references 7 and 8). Both SPIs e...

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Section: Fig 6 Ssupporting

confidence: 55%

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confidence: 99%

The Stringent Response Regulator DksA Is Required for Salmonella enterica Serovar Typhimurium Growth in Minimal Medium, Motility, Biofilm Formation, and Intestinal Colonization

et al. 2016

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“…NADH and NADPH fuel the antioxidant activities of alkyl hydroperoxidase and glutathione and thioredoxin reductases. NADH acts as a pro-oxidant that feeds reducing equivalents to flavoproteins (56). PPP is the major pathway for NADPH production, which raises the bacterial electrochemical potential that is involved in antioxidant tolerance.…”

Section: Discussionmentioning

confidence: 99%

Steady-State Hydrogen Peroxide Induces Glycolysis in Staphylococcus aureus and Pseudomonas aeruginosa

et al. 2014

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e Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) from human pathogens Staphylococcus aureus and Pseudomonas aeruginosa can be readily inhibited by reactive oxygen species (ROS)-mediated direct oxidation of their catalytic active cysteines. Because of the rapid degradation of H 2 O 2 by bacterial catalase, only steady-state but not one-dose treatment with H 2 O 2 rapidly induces glycolysis and the pentose phosphate pathway (PPP). We conducted transcriptome sequencing (RNA-seq) analyses to globally profile the bacterial transcriptomes in response to a steady level of H 2 O 2 , which revealed profound transcriptional changes, including the induced expression of glycolytic genes in both bacteria. Our results revealed that the inactivation of GAPDH by H 2 O 2 induces metabolic levels of glycolysis and the PPP; the elevated levels of fructose 1,6-biphosphate (FBP) and 2-keto-3-deoxy-6-phosphogluconate (KDPG) lead to dissociation of their corresponding glycolytic repressors (GapR and HexR, respectively) from their cognate promoters, thus resulting in derepression of the glycolytic genes to overcome H 2 O 2 -stalled glycolysis in S. aureus and P. aeruginosa, respectively. Both GapR and HexR may directly sense oxidative stresses, such as menadione. P athogenic bacteria, such as Pseudomonas aeruginosa andStaphylococcus aureus, need to conquer high concentrations of reactive oxygen species (ROS) that are produced by host phagocytic cells for sustained virulence (1). To this end, these bacteria use ROS-reactive small molecules, such as glutathione (GSH) and melanin in P. aeruginosa as well as coenzyme A and staphyloxanthin in S. aureus. These pathogens also produce a group of ROSdetoxifying enzymes, such as catalase, superoxide dismutase, hydroperoxide reductase, thioredoxin, and glutaredoxin, whose expression is induced by oxidative stress (2-4).It has been well documented that P. aeruginosa and S. aureus also mount global transcriptional changes by utilizing a group of thiol-based ROS-active transcription regulators, such as OxyR, SoxR, MgrA, OhrR, SarA, SarZ, MexR, OspR, CymR, AirSR, and AgrA (5-15). Upon oxidative stress, the specific cysteine groups in these regulatory proteins form sulfenic acids or disulfides, thus inducing conformational changes that attenuate their DNA binding affinities. Our previous work showed that a thiol-based, oxidation-sensing mechanism is utilized by these human pathogens to sense the host immune response and regulate a global change of their properties. ROS leads to activation of defense systems to reduce the oxidative threat as well as a major shift in the life forms of the pathogens (6, 11).ROS can efficiently oxidize the thiol group of active and allosteric cysteines in bacterial proteins, causing changes in their functions. Previously, we employed an isotopic orthogonal proteolysis-activity-based protein profiling (isoTOP-ABPP) technology to identify around 200 oxidation-sensitive cysteines and further determined that several of these proteins perform important redox-active functions...

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“…HemE is a uroporphyrinogen decarboxylase involved in the biosynthesis of the heme group, which is an important cofactor for antioxidant enzymes like catalase and peroxidase (63). Zwf is a glucose-6-phosphate dehydrogenase, which helps supply dihydronicotinamide-adenine dinucleotide phosphate (NADPH) through the pentose phosphate pathway (64), and NADPH is a cofactor used as a reducing agent by many metabolic enzymes (65,66). PqqL in E. coli is a putative zinc metalloprotease, but functionally it may be similar to PqqF in Klebsiella pneumoniae, which has a supportive role in pyrroloquinoline quinone biosynthesis (67).…”

Section: Discussionmentioning

confidence: 99%

Identification of 2-oxohistidine Interacting Proteins Using E. coli Proteome Chips

Lin

Tsai

Liu

et al. 2016

Molecular & Cellular Proteomics

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Cellular proteins are constantly damaged by reactive oxygen species generated by cellular respiration. Because of its metal-chelating property, the histidine residue is easily oxidized in the presence of Cu/Fe ions and H 2 O 2 via metal-catalyzed oxidation, usually converted to 2-oxohistidine. We hypothesized that cells may have evolved antioxidant defenses against the generation of 2-oxohistidine residues on proteins, and therefore there would be cellular proteins which specifically interact with this oxidized side chain. Using two chemically synthesized peptide probes containing 2-oxohistidine, high-throughput interactome screening was conducted using the E. coli K12 proteome microarray containing >4200 proteins. Ten interacting proteins were identified, and successfully validated using a third peptide probe, fluorescence polarization assays, as well as binding constant measurements. We discovered that 9 out of 10 identified proteins seemed to be involved in redox-related cellular functions. We also built the functional interaction network to reveal their interacting proteins. The network showed that our interacting proteins were enriched in oxido-reduction processes, ion binding, and carbon metabolism. A consensus motif was identified among these 10 bacterial interacting proteins based on bioinformatic analysis, which also appeared to be present on human S100A1 protein. Besides, we found that the consensus binding motif among our identified proteins, including bacteria and human, were located within ␣-helices and faced the outside of proteins. The combination of chemically engineered peptide probes with proteome microarrays proves to be an efficient discovery platform for protein interactomes of unusual post-translational modifications, and sensitive enough to detect even the insertion of a single oxygen atom in this case.

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Control of Redox Balance by the Stringent Response Regulatory Protein Promotes Antioxidant Defenses of Salmonella

Cited by 71 publications

References 48 publications

The Stringent Response Regulator DksA Is Required for Salmonella enterica Serovar Typhimurium Growth in Minimal Medium, Motility, Biofilm Formation, and Intestinal Colonization

The Stringent Response Regulator DksA Is Required for Salmonella enterica Serovar Typhimurium Growth in Minimal Medium, Motility, Biofilm Formation, and Intestinal Colonization

Steady-State Hydrogen Peroxide Induces Glycolysis in Staphylococcus aureus and Pseudomonas aeruginosa

Identification of 2-oxohistidine Interacting Proteins Using E. coli Proteome Chips

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