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Proc Natl Acad Sci U S A. 1994 Oct 25; 91(22): 10280–10284.

A distinct segment of the sigma 32 polypeptide is involved in DnaK-mediated negative control of the heat shock response in Escherichia coli.


Induction of heat shock proteins in Escherichia coli is caused by a transient increase in the cellular level of sigma 32 (the rpoH gene product), a protein required for transcription of heat shock genes. Both increased synthesis and stabilization of sigma 32 contribute to the increase in sigma 32. We previously showed that heat-induced translation of sigma 32-beta-galactosidase fusion protein encoded by an rpoH-lacZ gene fusion was mediated by an mRNA secondary structure formed between two 5'-proximal segments (A and B) of rpoH coding sequence spanning some 200 nt. We now report that a portion of the sigma 32 polypeptide that corresponds to further downstream (designated region C) is involved in the DnaK-mediated negative control resulting in the shutoff of heat-induced synthesis and degradation of fusion protein. Gene fusions carrying the 5' half (433 nt) or more of the rpoH coding sequence exhibited normal shutoff of synthesis, and the fusion proteins produced were very unstable, like authentic sigma 32; both the shutoff of synthesis and the instability of protein were markedly affected by the dnaK and dnaJ mutations. In contrast, gene fusions carrying < or = 364 nt (lacking region C) and a fusion carrying most of the rpoH sequence but with a frameshift mutation specifically affecting region C exhibited little or no shutoff and produced stable proteins. These results indicate that a distinct segment of sigma 32 plays a critical role in the negative feedback control of sigma 32. The control may be exerted during or after completion of sigma 32 synthesis mediated by interaction between nascent or mature sigma 32 and DnaK/DnaJ proteins.

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Selected References

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  • Straus DB, Walter WA, Gross CA. The heat shock response of E. coli is regulated by changes in the concentration of sigma 32. Nature. 1987 Sep 24;329(6137):348–351. [PubMed]
  • Tilly K, Spence J, Georgopoulos C. Modulation of stability of the Escherichia coli heat shock regulatory factor sigma. J Bacteriol. 1989 Mar;171(3):1585–1589. [PMC free article] [PubMed]
  • Kamath-Loeb AS, Gross CA. Translational regulation of sigma 32 synthesis: requirement for an internal control element. J Bacteriol. 1991 Jun;173(12):3904–3906. [PMC free article] [PubMed]
  • Nagai H, Yuzawa H, Yura T. Interplay of two cis-acting mRNA regions in translational control of sigma 32 synthesis during the heat shock response of Escherichia coli. Proc Natl Acad Sci U S A. 1991 Dec 1;88(23):10515–10519. [PMC free article] [PubMed]
  • Tilly K, McKittrick N, Zylicz M, Georgopoulos C. The dnaK protein modulates the heat-shock response of Escherichia coli. Cell. 1983 Sep;34(2):641–646. [PubMed]
  • Straus D, Walter W, Gross CA. DnaK, DnaJ, and GrpE heat shock proteins negatively regulate heat shock gene expression by controlling the synthesis and stability of sigma 32. Genes Dev. 1990 Dec;4(12A):2202–2209. [PubMed]
  • Straus DB, Walter WA, Gross CA. The activity of sigma 32 is reduced under conditions of excess heat shock protein production in Escherichia coli. Genes Dev. 1989 Dec;3(12A):2003–2010. [PubMed]
  • Taura T, Kusukawa N, Yura T, Ito K. Transient shut off of Escherichia coli heat shock protein synthesis upon temperature shift down. Biochem Biophys Res Commun. 1989 Aug 30;163(1):438–443. [PubMed]
  • Yura T, Nagai H, Mori H. Regulation of the heat-shock response in bacteria. Annu Rev Microbiol. 1993;47:321–350. [PubMed]
  • Bukau B. Regulation of the Escherichia coli heat-shock response. Mol Microbiol. 1993 Aug;9(4):671–680. [PubMed]
  • Gaitanaris GA, Papavassiliou AG, Rubock P, Silverstein SJ, Gottesman ME. Renaturation of denatured lambda repressor requires heat shock proteins. Cell. 1990 Jun 15;61(6):1013–1020. [PubMed]
  • Skowyra D, Georgopoulos C, Zylicz M. The E. coli dnaK gene product, the hsp70 homolog, can reactivate heat-inactivated RNA polymerase in an ATP hydrolysis-dependent manner. Cell. 1990 Sep 7;62(5):939–944. [PubMed]
  • Craig EA, Gross CA. Is hsp70 the cellular thermometer? Trends Biochem Sci. 1991 Apr;16(4):135–140. [PubMed]
  • Yuzawa H, Nagai H, Mori H, Yura T. Heat induction of sigma 32 synthesis mediated by mRNA secondary structure: a primary step of the heat shock response in Escherichia coli. Nucleic Acids Res. 1993 Nov 25;21(23):5449–5455. [PMC free article] [PubMed]
  • Sprengart ML, Fatscher HP, Fuchs E. The initiation of translation in E. coli: apparent base pairing between the 16srRNA and downstream sequences of the mRNA. Nucleic Acids Res. 1990 Apr 11;18(7):1719–1723. [PMC free article] [PubMed]
  • Faxén M, Plumbridge J, Isaksson LA. Codon choice and potential complementarity between mRNA downstream of the initiation codon and bases 1471-1480 in 16S ribosomal RNA affects expression of glnS. Nucleic Acids Res. 1991 Oct 11;19(19):5247–5251. [PMC free article] [PubMed]
  • Shean CS, Gottesman ME. Translation of the prophage lambda cl transcript. Cell. 1992 Aug 7;70(3):513–522. [PubMed]
  • Ito K, Kawakami K, Nakamura Y. Multiple control of Escherichia coli lysyl-tRNA synthetase expression involves a transcriptional repressor and a translational enhancer element. Proc Natl Acad Sci U S A. 1993 Jan 1;90(1):302–306. [PMC free article] [PubMed]
  • Casadaban MJ. Transposition and fusion of the lac genes to selected promoters in Escherichia coli using bacteriophage lambda and Mu. J Mol Biol. 1976 Jul 5;104(3):541–555. [PubMed]
  • Bukau B, Walker GC. Mutations altering heat shock specific subunit of RNA polymerase suppress major cellular defects of E. coli mutants lacking the DnaK chaperone. EMBO J. 1990 Dec;9(12):4027–4036. [PMC free article] [PubMed]
  • Ishiai M, Wada C, Kawasaki Y, Yura T. Mini-F plasmid mutants able to replicate in Escherichia coli deficient in the DnaJ heat shock protein. J Bacteriol. 1992 Sep;174(17):5597–5603. [PMC free article] [PubMed]
  • Hirano M, Shigesada K, Imai M. Construction and characterization of plasmid and lambda phage vector systems for study of transcriptional control in Escherichia coli. Gene. 1987;57(1):89–99. [PubMed]
  • Nagai H, Yano R, Erickson JW, Yura T. Transcriptional regulation of the heat shock regulatory gene rpoH in Escherichia coli: involvement of a novel catabolite-sensitive promoter. J Bacteriol. 1990 May;172(5):2710–2715. [PMC free article] [PubMed]
  • Kunkel TA, Roberts JD, Zakour RA. Rapid and efficient site-specific mutagenesis without phenotypic selection. Methods Enzymol. 1987;154:367–382. [PubMed]
  • Yano R, Imai M, Yura T. The use of operon fusions in studies of the heat-shock response: effects of altered sigma 32 on heat-shock promoter function in Escherichia coli. Mol Gen Genet. 1987 Apr;207(1):24–28. [PubMed]
  • Liberek K, Galitski TP, Zylicz M, Georgopoulos C. The DnaK chaperone modulates the heat shock response of Escherichia coli by binding to the sigma 32 transcription factor. Proc Natl Acad Sci U S A. 1992 Apr 15;89(8):3516–3520. [PMC free article] [PubMed]
  • Liberek K, Georgopoulos C. Autoregulation of the Escherichia coli heat shock response by the DnaK and DnaJ heat shock proteins. Proc Natl Acad Sci U S A. 1993 Dec 1;90(23):11019–11023. [PMC free article] [PubMed]
  • Gamer J, Bujard H, Bukau B. Physical interaction between heat shock proteins DnaK, DnaJ, and GrpE and the bacterial heat shock transcription factor sigma 32. Cell. 1992 May 29;69(5):833–842. [PubMed]
  • Georgopoulos C, Welch WJ. Role of the major heat shock proteins as molecular chaperones. Annu Rev Cell Biol. 1993;9:601–634. [PubMed]
  • McCarty JS, Walker GC. DnaK as a thermometer: threonine-199 is site of autophosphorylation and is critical for ATPase activity. Proc Natl Acad Sci U S A. 1991 Nov 1;88(21):9513–9517. [PMC free article] [PubMed]

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