Impact of ROS-Induced Damage of TCA Cycle Enzymes on Metabolism and Virulence of Salmonella enterica serovar Typhimurium
Autor(en): | Noster, Janina Persicke, Marcus Chao, Tzu-Chiao Krone, Lena Heppner, Bianca Hensel, Michael Hansmeier, Nicole |
Stichwörter: | aconitase; ESCHERICHIA-COLI ACONITASES; GENES; HYDROGEN-PEROXIDE; HYDROXYL RADICALS; IDENTIFICATION; iron-sulfur cluster damage; ISOCITRATE DEHYDROGENASE; metabolomics; Microbiology; OXIDATIVE STRESS; OXYR; PERIPLASMIC SUPEROXIDE-DISMUTASE; REACTIVE OXYGEN; superoxide dismutase | Erscheinungsdatum: | 2019 | Herausgeber: | FRONTIERS MEDIA SA | Journal: | FRONTIERS IN MICROBIOLOGY | Volumen: | 10 | Zusammenfassung: | Salmonella enterica serovar Typhimurium (STM) is exposed to reactive oxygen species (ROS) originating from aerobic respiration, antibiotic treatment, and the oxidative burst occurring inside the Salmonella-containing vacuole (SCV) within host cells. ROS damage cellular compounds, thereby impairing bacterial viability and inducing cell death. Proteins containing iron-sulfur (Fe-S) clusters are particularly sensitive and become non-functional upon oxidation. Comprising five enzymes with Fe-S clusters, the TCA cycle is a pathway most sensitive toward ROS. To test the impact of ROS-mediated metabolic perturbations on bacterial physiology, we analyzed the proteomic and metabolic profile of STM deficient in both cytosolic superoxide dismutases (Delta sodAB). Incapable of detoxifying superoxide anions (SOA), endogenously generated SOA accumulate during growth. Delta sodAB showed reduced abundance of aconitases, leading to a metabolic profile similar to that of an aconitase-deficient strain (Delta acnAB). Furthermore, we determined a decreased expression of acnA in STM Delta sodAB. While intracellular proliferation in RAW264.7 macrophages and survival of methyl viologen treatment were not reduced for STM Delta acnAB, proteomic profiling revealed enhanced stress response. We conclude that ROS-mediated reduced expression and damage of aconitase does not impair bacterial viability or virulence, but might increase ROS amounts in STM, which reinforces the bactericidal effects of antibiotic treatment and immune responses of the host. |
ISSN: | 1664302X | DOI: | 10.3389/fmicb.2019.00762 |
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