S-nitrosylation of peroxiredoxin 1 contributes to viability of lung epithelial cells during Bacillus anthracis infection

Biochim Biophys Acta Gen Subj. 2017 Jan;1861(1 Pt A):3019-3029. doi: 10.1016/j.bbagen.2016.09.006. Epub 2016 Sep 7.


Background: Using Bacillus anthracis as a model gram-positive bacterium, we investigated the effects of host protein S-nitrosylation during bacterial infection. B. anthracis possesses a bacterial nitric oxide synthase (bNOS) that is important for its virulence and survival. However, the role of S-nitrosylation of host cell proteins during B. anthracis infection has not been determined.

Methods: Nitrosoproteomic analysis of human small airway epithelial cells (HSAECs) infected with toxigenic B. anthracis Sterne was performed, identifying peroxiredoxin 1 (Prx1) as one predominant target. Peroxidase activity of Prx during infection was measured using 2-Cys-Peroxiredoxin activity assay. Chaperone activity of S-nitrosylated Prx1 was measured by insulin aggregation assay, and analysis of formation of multimeric species using Native PAGE. Griess assay and DAF-2DA fluorescence assay were used to measure NO production. Cell viability was measured using the Alamar Blue assay and the ATPlite assay (Perkin Elmer).

Results: S-nitrosylation of Prx1 in Sterne-infected HSAECs leads to a decrease in its peroxidase activity while enhancing its chaperone function. Treatment with bNOS inhibitor, or infection with bNOS deletion strain, reduces S-nitrosylation of Prx1 and decreases host cell survival. Consistent with this, siRNA knockdown of Prx1 lowers bNOS-dependent protection of HSAEC viability.

Conclusions: Anthrax infection results in S-nitrosylation of multiple host proteins, including Prx1. The nitrosylation-dependent decrease in peroxidase activity of Prx1 and increase in its chaperone activity is one factor contributing to enhancing infected cell viability.

General significance: These results provide a new venue of mechanistic investigation for inhalational anthrax that could lead to novel and potentially effective countermeasures.

Keywords: Bacillus anthracis; Nitric oxide synthase; Peroxiredoxin 1.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Anthrax / microbiology*
  • Anthrax / pathology*
  • Bacillus anthracis / drug effects
  • Bacillus anthracis / pathogenicity*
  • Cell Survival / drug effects
  • Epithelial Cells / drug effects
  • Epithelial Cells / metabolism
  • Epithelial Cells / microbiology*
  • Epithelial Cells / pathology*
  • Gene Deletion
  • Humans
  • Lung / pathology*
  • Mass Spectrometry
  • Models, Biological
  • Molecular Chaperones / metabolism
  • NG-Nitroarginine Methyl Ester / pharmacology
  • Nitric Oxide / metabolism
  • Nitric Oxide Synthase Type I / metabolism
  • Nitrosation
  • Peroxidase / metabolism
  • Peroxiredoxins / metabolism*
  • Reproducibility of Results


  • Molecular Chaperones
  • Nitric Oxide
  • 2-cys peroxiredoxin, human
  • Peroxiredoxins
  • Peroxidase
  • Nitric Oxide Synthase Type I
  • NG-Nitroarginine Methyl Ester