scholarly journals Differential heat shock gene hsp70-1 response to toxicants revealed by in vivo study of lungs in transgenic mice

2002 ◽  
Vol 7 (4) ◽  
pp. 387 ◽  
Author(s):  
Delphine Wirth ◽  
Elisabeth Christians ◽  
Carine Munaut ◽  
Cécile Dessy ◽  
Jean-Michel Foidart ◽  
...  
Keyword(s):  
Heat Shock ◽  
Transgenic Mice ◽  
In Vivo Study ◽  
Heat Shock Gene ◽  
Differential Heat ◽  
Shock Gene

A family of related proteins is encoded by the major Drosophila heat shock gene family

1982 ◽  
Vol 2 (3) ◽  
pp. 286-292
Author(s):  
S C Wadsworth
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Heat Shock Protein ◽  
Sodium Dodecyl ◽  
Heat Shock Gene ◽  
Partial Digestion ◽  
Shock Gene ◽  
Shock Proteins

At least four proteins of 70,000 to 75,000 molecular weight (70-75K) were synthesized from mRNA which hybridized with a cloned heat shock gene previously shown to be localized to the 87A and 87C heat shock puff sites. These in vitro-synthesized proteins were indistinguishable from in vivo-synthesized heat shock-induced proteins when analyzed on sodium dodecyl sulfate-polyacrylamide gels. A comparison of the pattern of this group of proteins synthesized in vivo during a 5-min pulse or during continuous labeling indicates that the 72-75K proteins are probably not kinetic precursors to the major 70K heat shock protein. Partial digestion products generated with V8 protease indicated that the 70-75K heat shock proteins are closely related, but that there are clear differences between them. The partial digestion patterns obtained from heat shock proteins from the Kc cell line and from the Oregon R strain of Drosophila melanogaster are very similar. Genetic analysis of the patterns of 70-75K heat shock protein synthesis indicated that the genes encoding at least two of the three 72-75K heat shock proteins are located outside of the major 87A and 87C puff sites.

Depressed expression of the inducible form of HSP 70 (HSP 72) in brain and heart after in vivo heat shock

1995 ◽  
Vol 269 (3) ◽  
pp. R608-R613 ◽  
Author(s):  
S. C. Beck ◽  
C. N. Paidas ◽  
H. Tan ◽  
J. Yang ◽  
A. De Maio
Keyword(s):  
Heat Shock ◽  
Cell Types ◽  
Heat Shock Gene ◽  
Hsp 70 ◽  
Shock Gene ◽  
Heat Shock Gene Expression ◽  
Total Body ◽  
Different Levels ◽  
Low Expression

The heat shock gene expression plays a role in the protection of cells from injury. In the present study, we have analyzed the expression of heat shock protein (HSP) 72 (the major inducible form of the HSP 70 family) in different rat organs after a total body hyperthermia. The content of HSP 72 was greatest in liver and colon. In contrast, accumulation of HSP 72 was low in heart and brain (3-5% and < 1% of the amount in liver, respectively). This low expression of HSP 72 in heart and brain could not be explained by a difference in the actual temperature within these organs. Analysis of cells in culture that resemble hepatocytes, myoblast, and neurons showed a pattern of HSP 72 expression similar to that observed in liver, heart, and brain in vivo after heat shock. These results suggest that this disparate expression of HSP 72 is due to intrinsic characteristics of the cell types rather than to physiological or environmental conditions. The differential expression of HSP 72 among different cell lines could be correlated with the different levels of protein synthesis protection.

scholarly journals The Heat Shock Protein YbeY Is Required for Optimal Activity of the 30S Ribosomal Subunit

2010 ◽  
Vol 192 (18) ◽  
pp. 4592-4596 ◽  
Author(s):  
Aviram Rasouly ◽  
Chen Davidovich ◽  
Eliora Z. Ron
Keyword(s):  
Heat Shock ◽  
Ribosomal Subunit ◽  
Heat Shock Gene ◽  
Wild Type ◽  
Lower Efficiency ◽  
Ribosomal Subunits ◽  
Translation Machinery ◽  
Shock Gene

ABSTRACT The highly conserved bacterial ybeY gene is a heat shock gene whose function is not fully understood. Previously, we showed that the YbeY protein is involved in protein synthesis, as Escherichia coli mutants with ybeY deleted exhibit severe translational defects in vivo. Here we show that the in vitro activity of the translation machinery of ybeY deletion mutants is significantly lower than that of the wild type. We also show that the lower efficiency of the translation machinery is due to impaired 30S small ribosomal subunits.

scholarly journals Dual Control of Helicobacter pylori Heat Shock Gene Transcription by HspR and HrcA

2004 ◽  
Vol 186 (10) ◽  
pp. 2956-2965 ◽  
Author(s):  
Gunther Spohn ◽  
Alberto Danielli ◽  
Davide Roncarati ◽  
Isabel Delany ◽  
Rino Rappuoli ◽  
...  
Keyword(s):  
Gene Expression ◽  
Helicobacter Pylori ◽  
Heat Shock ◽  
Heat Shock Gene ◽  
Inverted Repeats ◽  
Dual Control ◽  
Shock Gene ◽  
Heat Shock Gene Expression ◽  
H Pylori

ABSTRACT The HspR repressor regulates transcription of the groESL, hrcA-grpE-dnaK, and cbpA-hspR-orf operons of Helicobacter pylori. Here we show that two of the HspR-regulated operons, namely, the groESL and dnaK operons, encoding the major cellular chaperone machineries are also regulated by the H. pylori homologue of the HrcA repressor. Similarly to the hspR mutation, deletion of the hrcA gene also leads to complete derepression of the P gro and P hrc promoters. The presence of both HspR and HrcA is therefore necessary for regulated transcription from these promoters. HrcA binds directly to P gro and P hrc , likely contacting two inverted repeats with similarity to the CIRCE motif, which are present on both promoters. HrcA regulation is, however, shown to depend on binding of the HspR protein, since deletion of the HspR-binding site of the P gro promoter leads to loss of heat inducibility of this promoter. In contrast, transcription from the P cbp promoter is regulated solely by HspR. HspR is also shown to form oligomers in vivo through a stretch of hydrophobic repeats between amino acid positions 66 and 97. The implications of these findings for the elucidation of the networks regulating heat shock gene expression in H. pylori are discussed.

scholarly journals Role of DnaK in In Vitro and In Vivo Expression of Virulence Factors of Vibrio cholerae

1999 ◽  
Vol 67 (3) ◽  
pp. 1025-1033 ◽  
Author(s):  
Sabyasachi Chakrabarti ◽  
Nilanjan Sengupta ◽  
Rukhsana Chowdhury
Keyword(s):  
Heat Shock ◽  
Vibrio Cholerae ◽  
Virulence Factors ◽  
Heat Shock Gene ◽  
Insertion Mutant ◽  
In Vivo Expression ◽  
Shock Gene

ABSTRACT The dnaK gene of Vibrio cholerae was cloned, sequenced, and used to construct a dnaK insertion mutant which was then used to examine the role of DnaK in expression of the major virulence factors of this important human pathogen. The central regulator of several virulence genes of V. choleraeis ToxR, a transmembrane DNA binding protein. The V. cholerae dnaK mutant grown in standard laboratory medium exhibited phenotypes characteristic of cells deficient in ToxR activity. Using Northern blot analysis and toxR transcriptional fusions, we demonstrated a reduction in expression of the toxR gene in the dnaK mutant strain together with a concomitant increase in expression of a htpG-like heat shock gene that is located immediately upstream and is divergently transcribed fromtoxR. This may be due to increased heat shock induction in the dnaK mutant. In vivo, however, although expression from heat shock promoters in the dnaK mutant was similar to that observed in vitro, expression of both toxR andhtpG was comparable to that by the parental strain. In both strains, in vivo expression of toxR was significantly higher than that observed in vitro, but no reciprocal decrease inhtpG expression was observed. These results suggest that the modulation of toxR expression in vivo may be different from that observed in vitro.

Regulatory domains of the Gmhsp17.5-E heat shock promoter of soybean

1989 ◽  
Vol 9 (8) ◽  
pp. 3457-3463
Author(s):  
E Czarnecka ◽  
J L Key ◽  
W B Gurley
Keyword(s):  
Heat Shock ◽  
Promoter Activity ◽  
Heat Shock Gene ◽  
Base Pairs ◽  
Transgenic Expression ◽  
Cis Acting ◽  
Regulatory Domains ◽  
Shock Gene ◽  
Tata Motif

Promoter domains required for in vivo transcriptional expression of soybean heat shock gene Gmhsp17.5-E were identified by insertion-deletion mutagenesis with transgenic expression monitored in Agrobacterium tumefaciens-incited tumors of sunflower. Removal of the TATA-distal domain from position -1175 to position -259 had little effect on overall activity. The four regions contributing to promoter activity identified by this study all map within 244 base pairs from the start of transcription. The most distal cis-acting element of major significance was located from -244 to -179 and contains a conserved TATA-dyad motif centered at -220. Sequences from -179 to -40 comprise the TATA-proximal domain and include an AT-rich region and two sites containing heat shock consensus elements (HSEs). Deletion of the HSE centered at -93 (site 2) severely reduced transcriptional activity. Heat-inducible expression was also eliminated by internal deletion of either the TATA motif or the overlapping HSEs at site 1, indicating that each of these regions is also a major determinant of promoter activity.

scholarly journals Role of Region C in Regulation of the Heat Shock Gene-Specific Sigma Factor of Escherichia coli, ς32

1999 ◽  
Vol 181 (11) ◽  
pp. 3552-3561 ◽  
Author(s):  
Florence Arsène ◽  
Toshifumi Tomoyasu ◽  
Axel Mogk ◽  
Christiane Schirra ◽  
Agnes Schulze-Specking ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Heat Shock ◽  
Rna Polymerase ◽  
Binding Site ◽  
Heat Shock Gene ◽  
Ftsh Protease ◽  
Shock Gene ◽  
Stress Dependent

ABSTRACT Expression of heat shock genes is controlled in Escherichia coli by the antagonistic action of the ς32 subunit of RNA polymerase and the DnaK chaperone system, which inactivates ς32 by stress-dependent association and mediates ς32 degradation by the FtsH protease. A stretch of 23 residues (R122 to Q144) conserved among ς32 homologs, termed region C, was proposed to play a role in ς32degradation, and peptide analysis identified two potential DnaK binding sites central and peripheral to region C. Region C is thus a prime candidate for mediating stress control of ς32, a hypothesis that we tested in the present study. A peptide comprising the central DnaK binding site was an excellent substrate for FtsH, while a peptide comprising the peripheral DnaK binding site was a poor substrate. Replacement of a single hydrophobic residue in each DnaK binding site by negatively charged residues (I123D and F137E) strongly decreased the binding of the peptides to DnaK and the degradation by FtsH. However, introduction of these and additional region C alterations into the ς32 protein did not affect ς32 degradation in vivo and in vitro or DnaK binding in vitro. These findings do not support a role for region C in ς32 control by DnaK and FtsH. Instead, the ς32 mutants had reduced affinities for RNA polymerase and decreased transcriptional activities in vitro and in vivo. Furthermore, cysteines inserted into region C allowed cysteine-specific cross-linking of ς32 to RNA polymerase. Region C thus confers on ς32 a competitive advantage over other ς factors to bind RNA polymerase and thereby contributes to the rapidity of the heat shock response.

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