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Title: Starved Escherichia coli preserve reducing power under nitric oxide stress

Abstract

Nitric oxide (NO) detoxification enzymes, such as NO dioxygenase (NOD) and NO reductase (NOR), are important to the virulence of numerous bacteria. Pathogens use these defense systems to ward off immune-generated NO, and they do so in environments that contain additional stressors, such as reactive oxygen species, nutrient deprivation, and acid stress. NOD and NOR both use reducing equivalents to metabolically deactivate NO, which suggests that nutrient deprivation could negatively impact their functionality. To explore the relationship between NO detoxification and nutrient deprivation, we examined the ability of Escherichia coli to detoxify NO under different levels of carbon source availability in aerobic cultures. We observed failure of NO detoxification under both carbon source limitation and starvation, and those failures could have arisen from inabilities to synthesize Hmp (NOD of E. coli) and/or supply it with sufficient NADH (preferred electron donor). We found that when limited quantities of carbon source were provided, NO detoxification failed due to insufficient NADH, whereas starvation prevented Hmp synthesis, which enabled cells to maintain their NADH levels. This maintenance of NADH levels under starvation was confirmed to be dependent on the absence of Hmp. Intriguingly, these data show that under NO stress, carbon-starved E. coli are better positionedmore » with regard to reducing power to cope with other stresses than cells that had consumed an exhaustible amount of carbon. -- Highlights: •Carbon source availability is critical to aerobic E. coli NO detoxification. •Carbon source starvation, under NO stress, preserves intracellular NADH levels. •Preservation of NADH depends on starvation-dependent inhibition of Hmp induction.« less

Authors:
 [1];  [2];  [1];  [3]
  1. Department of Molecular Biology, Princeton University, Princeton, NJ (United States)
  2. Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ (United States)
  3. (United States)
Publication Date:
OSTI Identifier:
22598781
Resource Type:
Journal Article
Resource Relation:
Journal Name: Biochemical and Biophysical Research Communications; Journal Volume: 476; Journal Issue: 1; Other Information: Copyright (c) 2016 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
60 APPLIED LIFE SCIENCES; CARBON SOURCES; DETOXIFICATION; ESCHERICHIA COLI; FAILURES; FASTING; INHIBITION; NUTRIENTS; OXIDOREDUCTASES; PATHOGENS

Citation Formats

Gowers, Glen-Oliver F., Robinson, Jonathan L., Brynildsen, Mark P., E-mail: mbrynild@princeton.edu, and Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ. Starved Escherichia coli preserve reducing power under nitric oxide stress. United States: N. p., 2016. Web. doi:10.1016/J.BBRC.2016.05.082.
Gowers, Glen-Oliver F., Robinson, Jonathan L., Brynildsen, Mark P., E-mail: mbrynild@princeton.edu, & Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ. Starved Escherichia coli preserve reducing power under nitric oxide stress. United States. doi:10.1016/J.BBRC.2016.05.082.
Gowers, Glen-Oliver F., Robinson, Jonathan L., Brynildsen, Mark P., E-mail: mbrynild@princeton.edu, and Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ. Fri . "Starved Escherichia coli preserve reducing power under nitric oxide stress". United States. doi:10.1016/J.BBRC.2016.05.082.
@article{osti_22598781,
title = {Starved Escherichia coli preserve reducing power under nitric oxide stress},
author = {Gowers, Glen-Oliver F. and Robinson, Jonathan L. and Brynildsen, Mark P., E-mail: mbrynild@princeton.edu and Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ},
abstractNote = {Nitric oxide (NO) detoxification enzymes, such as NO dioxygenase (NOD) and NO reductase (NOR), are important to the virulence of numerous bacteria. Pathogens use these defense systems to ward off immune-generated NO, and they do so in environments that contain additional stressors, such as reactive oxygen species, nutrient deprivation, and acid stress. NOD and NOR both use reducing equivalents to metabolically deactivate NO, which suggests that nutrient deprivation could negatively impact their functionality. To explore the relationship between NO detoxification and nutrient deprivation, we examined the ability of Escherichia coli to detoxify NO under different levels of carbon source availability in aerobic cultures. We observed failure of NO detoxification under both carbon source limitation and starvation, and those failures could have arisen from inabilities to synthesize Hmp (NOD of E. coli) and/or supply it with sufficient NADH (preferred electron donor). We found that when limited quantities of carbon source were provided, NO detoxification failed due to insufficient NADH, whereas starvation prevented Hmp synthesis, which enabled cells to maintain their NADH levels. This maintenance of NADH levels under starvation was confirmed to be dependent on the absence of Hmp. Intriguingly, these data show that under NO stress, carbon-starved E. coli are better positioned with regard to reducing power to cope with other stresses than cells that had consumed an exhaustible amount of carbon. -- Highlights: •Carbon source availability is critical to aerobic E. coli NO detoxification. •Carbon source starvation, under NO stress, preserves intracellular NADH levels. •Preservation of NADH depends on starvation-dependent inhibition of Hmp induction.},
doi = {10.1016/J.BBRC.2016.05.082},
journal = {Biochemical and Biophysical Research Communications},
number = 1,
volume = 476,
place = {United States},
year = {Fri Jul 15 00:00:00 EDT 2016},
month = {Fri Jul 15 00:00:00 EDT 2016}
}