Modulation of DNA-binding activity of HspR by chaperones Free

Abstract

In , is the last gene of the operon. It encodes the repressor HspR, which regulates the expression from this operon by binding to a consensus upstream sequence known as HAIR (spR-ssociated nverted epeats). Previous investigations in the related Gram-positive bacterium have revealed that DnaK acts as a co-repressor for HspR. In this investigation, a similar situation was encountered using the corresponding mycobacterial pair. However, the novel feature unearthed in this study is that the mycobacterial GroELs, GroEL1 and GroEL2, considerably stimulate the HAIR-binding activity of the HspR-DnaK combination. That these GroELs play a role in the folding process was evident from the observation that when heat- or chemically denatured HspR was renatured, the protein gained optimal activity only if one of these GroEL class chaperones was present along with DnaK. The renaturation process was found to be dependent on ATP hydrolysis. The DnaK-dependent DNA-binding activity of HspR could also be stimulated by DnaJ, but GrpE, which is known to release DnaK-bound substrates, was found to be inhibitory. The results of this study suggest that protein folding plays a substantial role in the activation of HspR following heat shock and that DnaK may be involved in two ways – first, as a chaperone acting in concert with GroEL and/or DnaJ and second, as a co-repressor bound to HspR.

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2008-02-01
2024-03-29
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References

  1. Babst M., Hennecke H., Fischer H. M. 1996; Two different mechanisms are involved in the heat-shock regulation of chaperonin gene expression in Bradyrhizobium japonicum . Mol Microbiol 19:827–839
    [Google Scholar]
  2. Bahl H., Muller H., Behrens S., Joseph H., Narberhaus F. 1995; Expression of heat shock genes in Clostridium acetobutylicum . FEMS Microbiol Rev 17:341–348
    [Google Scholar]
  3. Basu A., Chawla-Sarkar M., Chakrabarti S., Das Gupta S. K. 2002; Origin binding activity of the mycobacterial plasmid pAL5000 replication protein RepB is stimulated through interactions with host factors and coupled expression of repA . J Bacteriol 184:2204–2214
    [Google Scholar]
  4. Brehmer D., Gassler C., Rist W., Mayer M. P., Bukau B. 2004; Influence of GrpE on DnaK–substrate interactions. J Biol Chem 279:27957–27964
    [Google Scholar]
  5. Bucca G., Brassington A. M., Schonfeld H. J., Smith C. P. 2000; The HspR regulon of Streptomyces coelicolor : a role for the DnaK chaperone as a transcriptional co-repressor. Mol Microbiol 38:1093–1103
    [Google Scholar]
  6. Bucca G., Brassington A. M., Hotchkiss G., Mersinias V., Smith C. P. 2003; Negative feedback regulation of dnaK , clpB and lon expression by the DnaK chaperone machine in Streptomyces coelicolor , identified by transcriptome and in vivo DnaK-depletion analysis. Mol Microbiol 50:153–166
    [Google Scholar]
  7. Bukau B. 1993; Regulation of the Escherichia coli heat-shock response. Mol Microbiol 9:671–680
    [Google Scholar]
  8. Georgopoulos C., Liberek K., Zylicz M., Ang D. 1994; Properties of the heat shock proteins of Escherichia coli and the autoregulation of the heat-shock response. In The Biology of Heat Shock Proteins and Molecular Chaperones pp 209–249 Edited by Morimoto A. T. R. I., Georgopoulos C. Cold Spring Harbor, NY: Cold Spring Harbor Laboratory;
    [Google Scholar]
  9. Goyal K., Qamra R., Mande S. C. 2006; Multiple gene duplication and rapid evolution in the groEL gene: functional implications. J Mol Evol 63:781–787
    [Google Scholar]
  10. Grandvalet C., de Crecy-Lagard V., Mazodier P. 1999; The ClpB ATPase of Streptomyces albus G belongs to the HspR heat shock regulon. Mol Microbiol 31:521–532
    [Google Scholar]
  11. Liberek K., Wall D., Georgopoulos C. 1995; The DnaJ chaperone catalytically activates the DnaK chaperone to preferentially bind the sigma 32 heat shock transcriptional regulator. Proc Natl Acad Sci U S A 92:6224–6228
    [Google Scholar]
  12. Lindquist S., Craig E. A. 1988; The heat-shock proteins. Annu Rev Genet 22:631–677
    [Google Scholar]
  13. Mayhew M., da Silva A. C., Martin J., Erdjument-Bromage H., Tempst P., Hartl F. U. 1996; Protein folding in the central cavity of the GroEL-GroES chaperonin complex. Nature 379:420–426
    [Google Scholar]
  14. Qamra R., Srinivas V., Mande S. C. 2004; Mycobacterium tuberculosis GroEL homologues unusually exist as lower oligomers and retain the ability to suppress aggregation of substrate proteins. J Mol Biol 342:605–617
    [Google Scholar]
  15. Raina S., Missiakas D., Georgopoulos C. 1995; The rpoE gene encoding the sigma E (sigma 24) heat shock sigma factor of Escherichia coli . EMBO J 14:1043–1055
    [Google Scholar]
  16. Rouviere P. E., De Las Penas A., Mecsas J., Lu C. Z., Rudd K. E., Gross C. A. 1995; rpoE , the gene encoding the second heat-shock sigma factor, sigma E, in Escherichia coli . EMBO J 14:1032–1042
    [Google Scholar]
  17. Sambrook J., Fritsch E. F., Maniatis T. 1989 Molecular Cloning: a Laboratory Manual , 2nd edn. Cold Spring Harbor, NY: Cold Spring Harbor Laboratory;
  18. Schulz A., Schumann W. 1996; hrcA, the first gene of the Bacillus subtilis dnaK operon encodes a negative regulator of class I heat shock genes. J Bacteriol 178:1088–1093
    [Google Scholar]
  19. Segal G., Ron E. Z. 1996; Heat shock activation of the groESL operon of Agrobacterium tumefaciens and the regulatory roles of the inverted repeat. J Bacteriol 178:3634–3640
    [Google Scholar]
  20. Stewart G. R., Snewin V. A., Walzl G., Hussell T., Tormay P., O'Gaora P., Goyal M., Betts J., Brown I. N., Young D. B. 2001; Overexpression of heat-shock proteins reduces survival of Mycobacterium tuberculosis in the chronic phase of infection. Nat Med 7:732–737
    [Google Scholar]
  21. Stewart G. R., Wernisch L., Stabler R., Mangan J. A., Hinds J., Laing K. G., Young D. B., Butcher P. D. 2002; Dissection of the heat-shock response in Mycobacterium tuberculosis using mutants and microarrays. Microbiology 148:3129–3138
    [Google Scholar]
  22. Stewart G. R., Robertson B. D., Young D. B. 2003; Tuberculosis: a problem with persistence. Nat Rev Microbiol 1:97–105
    [Google Scholar]
  23. Stewart G. R., Newton S. M., Wilkinson K. A., Humphreys I. R., Murphy H. N., Robertson B. D., Wilkinson R. J., Young D. B. 2005; The stress-responsive chaperone alpha-crystallin 2 is required for pathogenesis of Mycobacterium tuberculosis . Mol Microbiol 55:1127–1137
    [Google Scholar]
  24. Wilkinson K. A., Stewart G. R., Newton S. M., Vordermeier H. M., Wain J. R., Murphy H. N., Horner K., Young D. B., Wilkinson R. J. 2005; Infection biology of a novel alpha-crystallin of Mycobacterium tuberculosis : Acr2. J Immunol 174:4237–4243
    [Google Scholar]
  25. Yura T., Nagai H., Mori H. 1993; Regulation of the heat-shock response in bacteria. Annu Rev Microbiol 47:321–350
    [Google Scholar]
  26. Zuber U., Schumann W. 1994; CIRCE, a novel heat shock element involved in regulation of heat shock operon dnaK of Bacillus subtilis . J Bacteriol 176:1359–1363
    [Google Scholar]
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