1887

Abstract

This study shows that the iron-storage protein ferritin is a component of the redox-stress response in the obligate anaerobe . It is up-regulated at transcriptional level under aerobic conditions but constitutively expressed at low levels under anaerobic conditions. Northern hybridization and primer extension analysis revealed that is transcribed as a monocistronic mRNA of approximately 600 nt. Under reduced anaerobic conditions, mRNA levels were not dependent on the iron content of the culture medium. Following oxygen exposure message increased about 10-fold in iron-replete medium compared to a fourfold increase under low-iron conditions. Addition of the oxidant potassium ferricyanide induced expression of mRNA anaerobically, suggesting that the oxidation of the medium affected expression of . Two transcription initiation start sites were identified. Both transcripts were expressed constitutively under anaerobic conditions but one promoter was induced by oxidative stress or the addition of the oxidant potassium ferricyanide. The effect of redox stress on expression was further investigated by addition of diamide, a thiol-oxidizing agent, which induced mRNA levels anaerobically, suggesting that an unbalanced cellular redox state also affects expression. Induction by hydrogen peroxide and oxygen was decreased in an deletion mutant but some oxygen induction still occurred. This strongly suggests that is regulated by both the peroxide response transcriptional activator, OxyR, and another unidentified oxygen-dependent regulator. Taken together, these data show that mRNA levels are controlled by both iron and oxidative stress; this coordinated regulation may be important for survival in an adverse aerobic environment.

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2004-07-01
2024-04-24
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References

  1. Abdul-Tehrani H., Hudson A. J., Chang Y. S., Timms A. R., Hawkins C., Williams J. M., Harrison P. M., Guest J. R., Andrews S. C. 1999; Ferritin mutants of Escherichia coli are iron deficient and growth impaired, and fur mutants are iron deficient. J Bacteriol 181:1415–1428
    [Google Scholar]
  2. Andrews S. C. 1998; Iron storage in bacteria. Adv Microb Physiol 40:281–351
    [Google Scholar]
  3. Andrews S. C., Robinson A. K., Rodriguez-Quinones F. 2003; Bacterial iron homeostasis. FEMS Microbiol Lett 27:215–237 [CrossRef]
    [Google Scholar]
  4. Arosio P., Levi S. 2002; Ferritin, iron homeostasis, and oxidative damage. Free Radic Biol Med 33:457–463 [CrossRef]
    [Google Scholar]
  5. Baughn A. D., Malamy M. H. 2004; The strict anaerobe Bacteroides fragilis grows in and benefits from nanomolar concentrations of oxygen. Nature 427:441–444 [CrossRef]
    [Google Scholar]
  6. Bayley D. P., Rocha E. R., Smith C. J. 2000; Analysis of cepA and other Bacteroides fragilis genes reveals a unique promoter structure. FEMS Microbiol Lett 1931149–154
    [Google Scholar]
  7. Bereswill S., Greiner S., van Vliet A. H., Waidner B., Fassbinder F., Schiltz E., Kusters J. G., Kist M. 2000; Regulation of ferritin-mediated cytoplasmic iron storage by the ferric uptake regulator homolog (Fur) of Helicobacter pylori. J Bacteriol 182:5948–5953 [CrossRef]
    [Google Scholar]
  8. Chen C. Y., Morse S. A. 1999; Neisseria gonorrhoeae bacterioferritin: structural heterogeneity, involvement in iron storage and protection against oxidative stress. Microbiology 145:2967–2975
    [Google Scholar]
  9. Chen L., Keramati L., Helmann J. D. 1995; Coordinate regulation of Bacillus subtilis peroxide stress genes by hydrogen peroxide and metal ions. Proc Natl Acad Sci U S A 92:8190–8194 [CrossRef]
    [Google Scholar]
  10. da Costa P. N., Romao C. V., LeGall J., Xavier A. V., Melo E., Teixeira M., Saraiva L. M. 2001; The genetic organization of Desulfovibrio desulphuricans ATCC 27774 bacterioferritin and rubredoxin-2 genes: involvement of rubredoxin in iron metabolism. Mol Microbiol 41:217–227 [CrossRef]
    [Google Scholar]
  11. Delany I., Spohn G., Rappuoli R., Scarlato V. 2001; The Fur repressor controls transcription of iron-activated and -repressed genes in Helicobacter pylori. Mol Microbiol 42:1297–1309
    [Google Scholar]
  12. Devereux J., Haeberli P., Smithies O. 1984; A comprehensive set of sequence analysis programs for the VAX. Nucleic Acids Res 12:387–395 [CrossRef]
    [Google Scholar]
  13. Fong K. P., Gao L., Demuth D. R. 2003; luxS and arcB control aerobic growth of Actinobacillus actinomycetemcomitans under iron limitation. Infect Immun 71:298–308 [CrossRef]
    [Google Scholar]
  14. Herren C. D., Rocha E. R., Smith C. J. 2003; Genetic analysis of an important oxidative stress locus in the anaerobe Bacteroides fragilis. Gene 316:167–175 [CrossRef]
    [Google Scholar]
  15. Hirosue M., Kokeguchi S., Maeda H., Nishimura F., Takashiba S., Murayama Y. 2001; Characterization of two genes encoding ferritin-like protein in Actinobacillus actinomycetemcomitans. Microbiol Immunol 45:721–727 [CrossRef]
    [Google Scholar]
  16. Horsburgh M. J., Clements M. O., Crossley H., Ingham E., Foster S. J. 2001; PerR controls oxidative stress resistance and iron storage proteins and is required for virulence in Staphylococcus aureus. Infect Immun 69:3744–3754 [CrossRef]
    [Google Scholar]
  17. Loesche W. 1969; Oxygen sensitivity of various anaerobic bacteria. Appl Microbiol 18:723–727
    [Google Scholar]
  18. Massé E., Gottesman S. 2002; A small RNA regulates the expression of genes involved in iron metabolism in Escherichia coli. Proc Natl Acad Sci U S A 99:4620–4625 [CrossRef]
    [Google Scholar]
  19. Morris J. G. 1975; The physiology of obligate anaerobiosis. Adv Microb Physiol 12:169–246
    [Google Scholar]
  20. Otto B. R., Verweij-van Vught A. M., van Doorn J., Maclaren D. M. 1988; Outer membrane proteins of Bacteroides fragilis and Bacteroides vulgatus in relation to iron uptake and virulence. Microb Pathog 4:279–287 [CrossRef]
    [Google Scholar]
  21. Pan N., Imlay J. A. 2001; How does oxygen inhibit central metabolism in the obligate anaerobe Bacteroides thetaiotaomicron?. Mol Microbiol 39:1562–1571 [CrossRef]
    [Google Scholar]
  22. Privitera G., Dublanchet A., Sebald M. 1979; Transfer of multiple antibiotic resistance between subspecies of Bacteroides fragilis. J Infect Dis 139:97–101 [CrossRef]
    [Google Scholar]
  23. Ratledge C., Dover L. G. 2000; Iron metabolism in pathogenic bacteria. Annu Rev Microbiol 54:881–941 [CrossRef]
    [Google Scholar]
  24. Ratnayake D. B., Wai S. N., Shi Y., Amako K., Nakayama H., Nakayama K. 2000; Ferritin from the obligate anaerobe Porphyromonas gingivalis: purification, gene cloning and mutant studies. Microbiology 146:1119–1127
    [Google Scholar]
  25. Rocha E. R., Smith C. J. 1997; Regulation of Bacteroides fragilis katB mRNA expression by oxidative stress and carbon limitation. J Bacteriol 179:7033–7039
    [Google Scholar]
  26. Rocha E. R., Smith C. J. 1999; Role of the alkyl hydroperoxide reductase (ahpCF) gene in oxidative stress defense of the obligate anaerobe Bacteroides fragilis. J Bacteriol 181:5701–5710
    [Google Scholar]
  27. Rocha E. R., Andrews S. C., Keen J. N., Brock J. H. 1992; Isolation of a ferritin from Bacteroides fragilis. FEMS Microbiol Lett 74:207–212
    [Google Scholar]
  28. Rocha E. R., Selby T., Coleman J. P., Smith C. J. 1996; The oxidative stress response in an anaerobe, Bacteroides fragilis: a role for catalase in protection against hydrogen peroxide. J Bacteriol 178:6895–6903
    [Google Scholar]
  29. Rocha E. R., Owens G. Jr, Smith C. J. 2000; The redox-sensitive transcriptional activator OxyR regulates the peroxide response regulon in the obligate anaerobe Bacteroides fragilis. J Bacteriol 182:5059–5069 [CrossRef]
    [Google Scholar]
  30. Rocha E. R., Herren C. D., Smalley D. J., Smith C. J. 2003; The complex oxidative stress response of Bacteroides fragilis: the role of OxyR in control of gene expression. Anaerobe 9:165–173 [CrossRef]
    [Google Scholar]
  31. Romao C. V., Regalla M., Xavier A. V., Teixeira M., Liu M. Y., Le Gall J. 2000; A bacterioferritin from the strict anaerobe Desulfovibrio desulfuricans. ATCC 27774: Biochemistry 39:6841–6849 [CrossRef]
    [Google Scholar]
  32. Sambrook J., Fritsch E. F., Maniatis T. 1989 Molecular Cloning: a Laboratory Manual, 2nd edn. Cold Spring Harbor, NY: Cold Spring Harbor Laboratory;
  33. Shoemaker N. B., Getty C., Gardner J. F., Salyers A. A. 1986; Tn4351 transposes in Bacteroides spp. and mediates the integration of plasmid R751 into the Bacteroides chromosome. J Bacteriol 165:929–936
    [Google Scholar]
  34. Smith C. J., Rollins L. A., Parker A. C. 1995; Nucleotide sequence determination and genetic analysis of the Bacteroides plasmid, pBI143. Plasmid 34211–222 [CrossRef]
    [Google Scholar]
  35. Theil E. C. 2003; Ferritin at the crossroads of iron and oxygen metabolism. J Nutr (Suppl 1: 1331549S–1553S
    [Google Scholar]
  36. Touati D. 2000; Iron and oxidative stress in bacteria. Arch Biochem Biophys 373:1–6 [CrossRef]
    [Google Scholar]
  37. Ueshima J., Shoji M., Ratnayake D. B., Abe K., Yoshida S., Yamamoto K., Nakayama K. 2003; Purification, gene cloning, gene expression, and mutants of Dps from the obligate anaerobe Porphyromonas gingivalis. Infect Immun 2003; 71:1170–1178
    [Google Scholar]
  38. Varel V. H., Bryant M. P. 1974; Nutritional features of Bacteroides fragilis subsp. fragilis. Appl Microbiol 18:251–257
    [Google Scholar]
  39. Wai S. N., Nakayama K., Umene K., Moriya T., Amako K. 1996; Construction of a ferritin-deficient mutant of Campylobacter jejuni: contribution of ferritin to iron storage and protection against oxidative stress. Mol Microbiol 20:1127–1134 [CrossRef]
    [Google Scholar]
  40. Waidner B., Greiner S., Odenbreit S. & 12 other authors; 2002; Essential role of ferritin Pfr in Helicobacter pylori iron metabolism and gastric colonization. Infect Immun 70:3923–3929 [CrossRef]
    [Google Scholar]
  41. Whitehead T. T. 1997; Development of a bifunctional xylosidase/arabinosidase gene as a reporter gene for the gram-negative anaerobes Bacteroides and Porphyromonas, and Escherichia coli. Curr Microbiol 35:282–286 [CrossRef]
    [Google Scholar]
  42. Zheng M., Doan B., Schneider T. D., Storz G. 1999; OxyR and SoxRS regulation of fur. J Bacteriol 181:4639–4643
    [Google Scholar]
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