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Regulation of Escherichia coli hchA, a stress-inducible gene encoding molecular chaperone Hsp31.
Mol Microbiol. 2006 Jun; 60(6):1576-89.MM

Abstract

Escherichia coli Hsp31 is a homodimeric member of the ThiI/DJ-1/PfpI superfamily that combines molecular chaperone and aminopeptidase activities. Although it was originally identified on the basis of its induction by heat shock, little is known about the regulation of hchA, the structural gene encoding Hsp31. Here, we show that hchA is transcribed from dual promoters recognized by the sigmaD (sigma70) and sigmaS (sigma38) subunits of RNA polymerase (E). In exponentially growing cells, the nucleoid-binding protein H-NS downregulates Hsp31 synthesis, and hchA thermal induction primarily relies on the relief of H-NS-mediated silencing of EsigmaD-dependent transcription. This uncommon alternative to the use of a heat-shock sigma factor guarantees that Hsp31 concentration remains high throughout the length of the high temperature exposure phase. Entry into stationary phase leads to enhanced hchA transcription from its EsigmaS-dependent promoter. Consistent with a role of Hsp31 in the management of starvation, hchA null mutants exhibit a decrease ability to survive in deep stationary phase relative to hchA+ cells. Based on hchA heat-inducibility and membership in the sigmaS general stress regulon, we propose that Hsp31 performs a protective function under a wide range of stress conditions.

Authors+Show Affiliations

Department of Bioengineering, University of Washington, Seattle, WA, USA.No affiliation info available

Pub Type(s)

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

Language

eng

PubMed ID

16796689

Citation

Mujacic, Mirna, and François Baneyx. "Regulation of Escherichia Coli hchA, a Stress-inducible Gene Encoding Molecular Chaperone Hsp31." Molecular Microbiology, vol. 60, no. 6, 2006, pp. 1576-89.
Mujacic M, Baneyx F. Regulation of Escherichia coli hchA, a stress-inducible gene encoding molecular chaperone Hsp31. Mol Microbiol. 2006;60(6):1576-89.
Mujacic, M., & Baneyx, F. (2006). Regulation of Escherichia coli hchA, a stress-inducible gene encoding molecular chaperone Hsp31. Molecular Microbiology, 60(6), 1576-89.
Mujacic M, Baneyx F. Regulation of Escherichia Coli hchA, a Stress-inducible Gene Encoding Molecular Chaperone Hsp31. Mol Microbiol. 2006;60(6):1576-89. PubMed PMID: 16796689.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Regulation of Escherichia coli hchA, a stress-inducible gene encoding molecular chaperone Hsp31. AU - Mujacic,Mirna, AU - Baneyx,François, PY - 2006/6/27/pubmed PY - 2006/8/23/medline PY - 2006/6/27/entrez SP - 1576 EP - 89 JF - Molecular microbiology JO - Mol Microbiol VL - 60 IS - 6 N2 - Escherichia coli Hsp31 is a homodimeric member of the ThiI/DJ-1/PfpI superfamily that combines molecular chaperone and aminopeptidase activities. Although it was originally identified on the basis of its induction by heat shock, little is known about the regulation of hchA, the structural gene encoding Hsp31. Here, we show that hchA is transcribed from dual promoters recognized by the sigmaD (sigma70) and sigmaS (sigma38) subunits of RNA polymerase (E). In exponentially growing cells, the nucleoid-binding protein H-NS downregulates Hsp31 synthesis, and hchA thermal induction primarily relies on the relief of H-NS-mediated silencing of EsigmaD-dependent transcription. This uncommon alternative to the use of a heat-shock sigma factor guarantees that Hsp31 concentration remains high throughout the length of the high temperature exposure phase. Entry into stationary phase leads to enhanced hchA transcription from its EsigmaS-dependent promoter. Consistent with a role of Hsp31 in the management of starvation, hchA null mutants exhibit a decrease ability to survive in deep stationary phase relative to hchA+ cells. Based on hchA heat-inducibility and membership in the sigmaS general stress regulon, we propose that Hsp31 performs a protective function under a wide range of stress conditions. SN - 0950-382X UR - https://www.unboundmedicine.com/medline/citation/16796689/Regulation_of_Escherichia_coli_hchA_a_stress_inducible_gene_encoding_molecular_chaperone_Hsp31_ L2 - https://doi.org/10.1111/j.1365-2958.2006.05207.x DB - PRIME DP - Unbound Medicine ER -