1887

Microbiology Society logo

Volume 148, Issue 4

aconitases and oxidative stress: post-transcriptional regulation of expression Free

Abstract

possesses two aconitases, a stationary-phase enzyme (AcnA), which is induced by iron and oxidative stress, and a major but less stable enzyme (AcnB), synthesized during exponential growth. In addition to the catalytic activities of the holo-proteins, the apo-proteins function as post-transcriptional regulators by site-specific binding to mRNAs. Thus, it has been suggested that inactivation of the enzymes could mediate a rapidly reacting post-transcriptional component of the bacterial oxidative stress response. Here it is shown that mutants are hypersensitive to the redox-stress reagents HO and methyl viologen. Proteomic analyses further revealed that the level of superoxide dismutase (SodA) is enhanced in and mutants, and by exposure to methyl viologen. The amounts of other proteins, including thioredoxin reductase, 2-oxoglutarate dehydrogenase, succinyl-CoA synthetase and chaperone proteins, were also affected in the mutants. The altered patterns of expression were confirmed in studies with – reporter strains. Quantitative Northern blotting indicated that AcnA enhances the stability of the transcript, whereas AcnB lowers its stability. Direct evidence that the apo-proteins have positive (AcnA) and negative (AcnB) effects on SodA synthesis was obtained from transcription–translation experiments. It is suggested that the aconitase proteins of serve as a protective buffer against the basal level of oxidative stress that accompanies aerobic growth by acting as a sink for reactive oxygen species and by modulating translation of the transcript.

  • Received:
  • Accepted:
  • Revised:
  • Published Online:
Keyword(s): Acn, aconitase , iron–sulphur protein , IRP, iron regulatory protein , MV, methyl viologen , ODH, 2-oxoglutarate dehydrogenase , protein–mRNA interactions , proteomics , SCS, succinyl-CoA synthetase , SodA, superoxide dismutase and UTR, untranslated region
© Microbiology Society
Loading

Article metrics loading...

/content/journal/micro/10.1099/00221287-148-4-1027
2002-04-01
2024-04-20
Loading full text...

Full text loading...

/deliver/fulltext/micro/148/4/1481027a.html?itemId=/content/journal/micro/10.1099/00221287-148-4-1027&mimeType=html&fmt=ahah

References

  1. Aiba H., Adhya S., De Crombrugghe B. 1981; Evidence for two functional gal promoters in intact Escherichia coli cells. J Biol Chem 256:1905–1910
     [Google Scholar]
  2. Alen C., Sonenshein A. L. 1999; Bacillus subtilis aconitase is an RNA-binding protein. Proc Natl Acad Sci USA 96:10412–10417 [CrossRef]
     [Google Scholar]
  3. Beinert H., Kennedy M. C., Stout C. D. 1996; Aconitase as iron–sulfur protein, enzyme and iron-regulatory protein. Chem Rev 96:2335–2373 [CrossRef]
     [Google Scholar]
  4. Benov L., Fridovich I. 1998; Growth in iron-enriched medium partially compensates Escherichia coli for the lack of manganese and iron superoxide dismutase. J Biol Chem 273:10313–10316 [CrossRef]
     [Google Scholar]
  5. Boni I. V., Artamonova V. S., Dreyfus M. 2000; The last RNA-binding repeat of the Escherichia coli ribosomal protein S1 is specifically involved in autogenous control. J Bacteriol 182:5872–5879 [CrossRef]
     [Google Scholar]
  6. Bradbury A. J., Gruer M. J., Rudd K. E., Guest J. R. 1996; The second aconitase (AcnB) of Escherichia coli . Microbiology 142:389–400 [CrossRef]
     [Google Scholar]
  7. Carlioz A., Touati D. 1986; Isolation of superoxide dismutase mutants in Escherichia coli : is superoxide dismutase necessary for aerobic life?. EMBO J 5:623–630
     [Google Scholar]
  8. Compan I., Touati D. 1993; Interaction of six global transcription regulators in expression of manganese superoxide dismutase in Escherichia coli K-12. J Bacteriol 175:1687–1696
     [Google Scholar]
  9. Cunningham L., Gruer M. J., Guest J. R. 1997; Transcriptional regulation of the aconitase genes ( acnA and acnB ) of Escherichia coli . Microbiology 143:3795–3805 [CrossRef]
     [Google Scholar]
  10. Gardner P. R., Fridovich I. 1992; Inactivation–reactivation of aconitase in Escherichia coli : a sensitive measure of superoxide radical. J Biol Chem 267:8757–8763
     [Google Scholar]
  11. Gardner P. R., Costantino G., Szabo C., Salzman A. L. 1997; Nitric oxide sensitivity of the aconitases. J Biol Chem 272:25071–25076 [CrossRef]
     [Google Scholar]
  12. Gifford C. M., Wallace S. S. 1999; The genes encoding formamidopyrimidine and MutY DNA glycosylases in Escherichia coli are transcribed as part of complex operons. J Bacteriol 181:4223–4236
     [Google Scholar]
  13. Greenberg J. T., Monach P., Chou J. H., Josephy D., Demple B. 1990; Positive control of a global antioxidant defense regulon activated by superoxide generating agents in Escherichia coli . Proc Natl Acad Sci USA 87:6181–6185 [CrossRef]
     [Google Scholar]
  14. Gruer M. J., Guest J. R. 1994; Two genetically-distinct and differentially-regulated aconitases (AcnA and AcnB) in Escherichia coli . Microbiology 140:2531–2541 [CrossRef]
     [Google Scholar]
  15. Gruer M. J., Artymiuk P. J., Guest J. R. 1997a; The aconitase family: three structural variations on a common theme. Trend Biochem Sci 22:3–6 [CrossRef]
     [Google Scholar]
  16. Gruer M. J., Bradbury A. J., Guest J. R. 1997b; Construction and properties of aconitase mutants of Escherichia coli . Microbiology 143:1837–1846 [CrossRef]
     [Google Scholar]
  17. Hentze M. W., Kuhn L. C. 1996; Molecular control of vertebrate iron metabolism: mRNA-based regulatory circuits operated by iron, nitric oxide and oxidative stress. Proc Natl Acad Sci USA 93:8175–8182 [CrossRef]
     [Google Scholar]
  18. Holland R. D., Duffy C. R., Rafii F., Sutherland J. B., Heinze T. M., Holder C. L., Voorhees K. J., Lay J. O. 1999; Identification of bacterial proteins observed in MALDI TOF mass spectra from whole cells. Anal Chem 71:3226–3230 [CrossRef]
     [Google Scholar]
  19. Jordan P. A., Tang Y., Bradbury A. J., Thomson A. J., Guest J. R. 1999; Biochemical and spectroscopic characterisation of Escherichia coli aconitases (AcnA and AcnB). Biochem J 344:739–746 [CrossRef]
     [Google Scholar]
  20. Keyer K., Imlay J. A. 1996; Superoxide accelerates DNA damage by elevating free-iron levels. Proc Natl Acad Sci USA 93:13635–13640 [CrossRef]
     [Google Scholar]
  21. Lennox E. S. 1955; Transduction of linked genetic characters of host by bacteriophage P1. Virology 1:190–206 [CrossRef]
     [Google Scholar]
  22. Messner K. R., Imlay J. A. 1999; The identification of primary sites of superoxide and hydrogen peroxide formation in the aerobic respiratory chain and sulfite reductase complex of Escherichia coli . J Biol Chem 274:10119–10128 [CrossRef]
     [Google Scholar]
  23. Miller J. H. 1972; Assay of β-galactosidase. In Experiments in Molecular Genetics pp 352–355 Cold Spring Harbor, NY: Cold Spring Harbor Laboratory;
     [Google Scholar]
  24. Nunoshiba T., Obata F., Boss A. C., Oikawa S., Mori T., Kawanishi S., Yamamoto K. 1999; Role of iron and superoxide for generation of hydroxyl radical oxidative DNA lesions, and mutagenesis in Escherichia coli . J Biol Chem 274:34832–34837 [CrossRef]
     [Google Scholar]
  25. Pomposiello P. J., Bennik M. H. J., Demple B. 2001; Genome-wide transcriptional profiling of the Escherichia coli responses to superoxide stress and sodium salicylate. J Bacteriol 183:3890–3902 [CrossRef]
     [Google Scholar]
  26. Prodromou C., Haynes M. J., Guest J. R. 1991; The aconitase of Escherichia coli : purification of the enzyme and molecular cloning and map location of the gene ( acn ). J Gen Microbiol 137:2505–2515 [CrossRef]
     [Google Scholar]
  27. Richarme G., Caldas T. D. 1997; Chaperone properties of the bacterial periplasmic substrate-binding proteins. J Biol Chem 272:15607–15612 [CrossRef]
     [Google Scholar]
  28. Sambrook J., Fritsch E. F., Maniatis T. 1989 Molecular Cloning: a Laboratory Manual, 2nd edn. Cold Spring Harbor, NY: Cold Spring Harbor Laboratory;
     [Google Scholar]
  29. Silhavy T. J., Barman M. L., Enquist L. W. 1984 Experiments with Gene Fusions Cold Spring Harbor, NY: Cold Spring Harbor Laboratory;
     [Google Scholar]
  30. Skouv J., Schnier J., Rasmussen M. D., Subramanian A. R., Pedersen S. 1990; Ribosomal protein S1 of Escherichia coli is the effector for the regulation of its own synthesis. J Biol Chem 265:17044–17049
     [Google Scholar]
  31. Somerville G., Miloryak C. A., Reitzer L. 1999; Physiological characterization of Pseudomonas aeruginosa during exotoxin A synthesis: glutamate, iron limitation, and aconitase activity. J Bacteriol 181:1072–1078
     [Google Scholar]
  32. Tang Y., Guest J. R. 1999; Direct evidence for mRNA binding and post-transcriptional regulation by Escherichia coli aconitases. Microbiology 145:3069–3079
     [Google Scholar]
  33. Wilson T. J. G., Bertrand N., Tang J.-L., Feng J.-X., Pan M.-Q., Barber C. E., Dow J. M., Daniels M. J. 1998; The rpfA gene of Xanthomonas campestris pathovar campestris , which is involved in the regulation of pathogenicity factor production, encodes an aconitase. Mol Microbiol 28:961–970 [CrossRef]
     [Google Scholar]
  34. Yoshida T., Ueguchi C., Yamada H., Mizuno T. 1993; Function of the Escherichia coli nucleoid protein, H–NS: molecular analysis of a subset of proteins whose expression is enhanced in an hns deletion mutant. Mol Gen Genet 237:113–122
     [Google Scholar]
http://instance.metastore.ingenta.com/content/journal/micro/10.1099/00221287-148-4-1027
Loading
Escherichia coli aconitases and oxidative stress: post-transcriptional regulation of sodA expression
Microbiology 148, 1027 (2002); https://doi.org/10.1099/00221287-148-4-1027
/content/journal/micro/10.1099/00221287-148-4-1027
/content/journal/micro/10.1099/00221287-148-4-1027
Loading

Data & Media loading...

Most cited Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error