Endogenous occurrence of protein S-guanylation in Escherichia coli: Target identification and genetic regulation

Biochem Biophys Res Commun. 2016 Sep 9;478(1):7-11. doi: 10.1016/j.bbrc.2016.07.110. Epub 2016 Jul 27.


8-Nitroguanosine 3',5'-cyclic monophosphate (8-nitro-cGMP) is a nitrated cGMP derivative formed in response to nitric oxide (NO) and reactive oxygen species (ROS). It can cause a post-translational modification (PTM) of protein thiols through cGMP adduction (protein S-guanylation). Accumulating evidence has suggested that, in mammals, S-guanylation of redox-sensor proteins may implicate in regulation of adaptive responses against ROS-associated oxidative stress. Occurrence as well as protein targets of S-guanylation in bacteria remained unknown, however. Here we demonstrated, for the first time, the endogenous occurrence of protein S-guanylation in Escherichia coli (E. coli). Western blotting using anti-S-guanylation antibody clearly showed that multiple proteins were S-guanylated in E. coli. Interestingly, some of those proteins were more intensely S-guanylated when bacteria were cultured under static culture condition than shaking culture condition. It has been known that E. coli is deficient of guanylate cyclase, an enzyme indispensable for 8-nitro-cGMP formation in mammals. We found that adenylate cyclase from E. coli potentially catalyzed 8-nitro-cGMP formation from its precursor 8-nitroguanosine 5'-triphosphate. More importantly, E. coli lacking adenylate cyclase showed significantly reduced formation of S-guanylated proteins. Our S-guanylation proteomics successfully identified S-guanylation protein targets in E. coli, including chaperons, ribosomal proteins, and enzymes which associate with protein synthesis, redox regulation and metabolism. Understanding of functional impacts for protein S-guanylation in bacterial signal transduction is necessary basis for development of potential chemotherapy and new diagnostic strategy for control of pathogenic bacterial infections.

Keywords: 8-Nitro-cGMP; Adenylate cyclase; Escherichia coli; Nitric oxide; Protein S-guanylation; Redox signaling.

MeSH terms

  • Adenylyl Cyclases / metabolism
  • Cyclic GMP / analogs & derivatives*
  • Cyclic GMP / metabolism
  • Escherichia coli / metabolism*
  • Escherichia coli Proteins / metabolism*
  • Nitric Oxide / metabolism
  • Nitrite Reductases / metabolism
  • Oxidation-Reduction
  • Oxidative Stress
  • Protein Processing, Post-Translational
  • Proteomics
  • Reactive Oxygen Species / metabolism
  • Signal Transduction


  • 8-nitroguanosine 3',5'-cyclic monophosphate
  • Escherichia coli Proteins
  • Reactive Oxygen Species
  • Nitric Oxide
  • Nitrite Reductases
  • Adenylyl Cyclases
  • Cyclic GMP