scholarly journals DNA binding of heat shock factor to the heat shock element is insufficient for transcriptional activation in murine erythroleukemia cells.

1990 ◽  
Vol 10 (4) ◽  
pp. 1600-1608 ◽  
Author(s):  
J O Hensold ◽  
C R Hunt ◽  
S K Calderwood ◽  
D E Housman ◽  
R E Kingston
Keyword(s):  
Heat Shock ◽  
Heat Shock Response ◽  
Transcriptional Activation ◽  
Heat Shock Factor ◽  
Apparent Size ◽  
Binding Activity ◽  
Heat Shock Element ◽  
Shock Response ◽  
Murine Erythroleukemia ◽  
Regulated Gene Expression

The heat shock response is among the most highly conserved examples of regulated gene expression, being present in all cellular organisms. Transcriptional activation of heat shock genes by increased temperature or other cellular stresses is mediated by the binding of a heat shock factor (HSF) to a conserved nucleotide sequence (the heat shock element) present in the promoter of heat-inducible genes. Despite the high degree of conservation of this response, embryonic stages of development are characterized by the absence of a heat shock response. Murine erythroleukemia (MEL) cells also lack this response, and we report here a detailed characterization of this defect for one of the most highly conserved of these genes, hsp70. Surprisingly, heat-induced transcriptional activation of this gene does not occur, despite the induction of a protein with the binding specificity of murine HSF. However, the MEL HSF differs slightly in apparent size from the HSF in 3T3 cells, which exhibit a normal heat shock response. These data suggest that activation of mammalian HSF by heat requires at least two separate steps: an alteration of binding activity followed by further modification that activates transcription. MEL cells do not respond to heat shock because they lack the ability to perform this secondary modification. These cells provide a useful system for characterizing heat shock activation in mammals.

DNA binding of heat shock factor to the heat shock element is insufficient for transcriptional activation in murine erythroleukemia cells

1990 ◽  
Vol 10 (4) ◽  
pp. 1600-1608
Author(s):  
J O Hensold ◽  
C R Hunt ◽  
S K Calderwood ◽  
D E Housman ◽  
R E Kingston
Keyword(s):  
Heat Shock ◽  
Heat Shock Response ◽  
Transcriptional Activation ◽  
Heat Shock Factor ◽  
Apparent Size ◽  
Binding Activity ◽  
Heat Shock Element ◽  
Shock Response ◽  
Murine Erythroleukemia ◽  
Regulated Gene Expression

The heat shock response is among the most highly conserved examples of regulated gene expression, being present in all cellular organisms. Transcriptional activation of heat shock genes by increased temperature or other cellular stresses is mediated by the binding of a heat shock factor (HSF) to a conserved nucleotide sequence (the heat shock element) present in the promoter of heat-inducible genes. Despite the high degree of conservation of this response, embryonic stages of development are characterized by the absence of a heat shock response. Murine erythroleukemia (MEL) cells also lack this response, and we report here a detailed characterization of this defect for one of the most highly conserved of these genes, hsp70. Surprisingly, heat-induced transcriptional activation of this gene does not occur, despite the induction of a protein with the binding specificity of murine HSF. However, the MEL HSF differs slightly in apparent size from the HSF in 3T3 cells, which exhibit a normal heat shock response. These data suggest that activation of mammalian HSF by heat requires at least two separate steps: an alteration of binding activity followed by further modification that activates transcription. MEL cells do not respond to heat shock because they lack the ability to perform this secondary modification. These cells provide a useful system for characterizing heat shock activation in mammals.

scholarly journals Regulation of heat shock factor in Schizosaccharomyces pombe more closely resembles regulation in mammals than in Saccharomyces cerevisiae.

1991 ◽  
Vol 11 (1) ◽  
pp. 281-288 ◽  
Author(s):  
G J Gallo ◽  
T J Schuetz ◽  
R E Kingston
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Heat Shock ◽  
Dna Binding ◽  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Heat Shock Response ◽  
Heat Shock Factor ◽  
Regulatory Sequence ◽  
Heat Shock Element ◽  
Shock Response

The heat shock response appears to be universal. All eucaryotes studied encode a protein, heat shock factor (HSF), that is believed to regulate transcription of heat shock genes. This protein binds to a regulatory sequence, the heat shock element, that is absolutely conserved among eucaryotes. We report here the identification of HSF in the fission yeast Schizosaccharomyces pombe. HSF binding was not observed in extracts from normally growing S. pombe (28 degrees C) but was detected in increasing amounts as the temperature of heat shock increased between 39 and 45 degrees C. This regulation is in contrast to that observed in Saccharomyces cerevisiae, in which HSF binding is detectable at both normal and heat shock temperatures. The S. pombe factor bound specifically to the heat shock element, as judged by methylation interference and DNase I protection analysis. The induction of S. pombe HSF was not inhibited by cycloheximide, suggesting that induction occurs posttranslationally, and the induced factor was shown to be phosphorylated. S. pombe HSF was purified to near homogeneity and was shown to have an apparent mobility of approximately 108 kDa. Since heat-induced DNA binding by HSF had previously been demonstrated only in metazoans, the conservation of heat-induced DNA binding by HSF among S. pombe and metazoans suggests that this mode of regulation is evolutionarily ancient.

scholarly journals Complex modes of heat shock factor activation.

1990 ◽  
Vol 10 (2) ◽  
pp. 752-759 ◽  
Author(s):  
V Zimarino ◽  
C Tsai ◽  
C Wu
Keyword(s):  
Protein Synthesis ◽  
Heat Shock ◽  
Transcriptional Activation ◽  
Heat Shock Factor ◽  
Binding Activity ◽  
Regulatory Sequence ◽  
Heat Shock Genes ◽  
Heat Shock Element ◽  
Complex Modes ◽  
Environmental Temperatures

Eucaryotic organisms respond to elevated environmental temperatures by rapidly activating the expression of heat shock genes. The transcriptional activation of heat shock genes is mediated by a conserved upstream regulatory sequence, the heat shock element (HSE). Using an HSE-binding assay, we show that a cellular factor present in a range of vertebrate species binds specifically to the HSE. This factor is presumably the transcriptional activator of heat shock genes, heat shock factor (HSF). In vertebrates, the binding of HSF to the HSE was induced when cells were subjected to heat shock at high temperatures, even in the absence of protein synthesis. Under mild heat shock conditions, HSF binding was induced to a lesser extent, but this induction required protein synthesis, suggesting that synthesis of HSF itself, or an activating factor, is necessary for response to heat shock at intermediate temperatures. The inducibility of HSF binding in higher eucaryotes is contrasted with constitutive HSF binding activity in fungi. It appears that despite conservation of the HSE in evolution, the means by which HSF is activated to bind DNA in higher and lower eucaryotes may have diverged.

Complex modes of heat shock factor activation

1990 ◽  
Vol 10 (2) ◽  
pp. 752-759
Author(s):  
V Zimarino ◽  
C Tsai ◽  
C Wu
Keyword(s):  
Protein Synthesis ◽  
Heat Shock ◽  
Transcriptional Activation ◽  
Heat Shock Factor ◽  
Binding Activity ◽  
Regulatory Sequence ◽  
Heat Shock Genes ◽  
Heat Shock Element ◽  
Complex Modes ◽  
Environmental Temperatures

Eucaryotic organisms respond to elevated environmental temperatures by rapidly activating the expression of heat shock genes. The transcriptional activation of heat shock genes is mediated by a conserved upstream regulatory sequence, the heat shock element (HSE). Using an HSE-binding assay, we show that a cellular factor present in a range of vertebrate species binds specifically to the HSE. This factor is presumably the transcriptional activator of heat shock genes, heat shock factor (HSF). In vertebrates, the binding of HSF to the HSE was induced when cells were subjected to heat shock at high temperatures, even in the absence of protein synthesis. Under mild heat shock conditions, HSF binding was induced to a lesser extent, but this induction required protein synthesis, suggesting that synthesis of HSF itself, or an activating factor, is necessary for response to heat shock at intermediate temperatures. The inducibility of HSF binding in higher eucaryotes is contrasted with constitutive HSF binding activity in fungi. It appears that despite conservation of the HSE in evolution, the means by which HSF is activated to bind DNA in higher and lower eucaryotes may have diverged.

Regulation of heat shock factor in Schizosaccharomyces pombe more closely resembles regulation in mammals than in Saccharomyces cerevisiae

1991 ◽  
Vol 11 (1) ◽  
pp. 281-288
Author(s):  
G J Gallo ◽  
T J Schuetz ◽  
R E Kingston
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Heat Shock ◽  
Dna Binding ◽  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Heat Shock Response ◽  
Heat Shock Factor ◽  
Regulatory Sequence ◽  
Heat Shock Element ◽  
Shock Response

The heat shock response appears to be universal. All eucaryotes studied encode a protein, heat shock factor (HSF), that is believed to regulate transcription of heat shock genes. This protein binds to a regulatory sequence, the heat shock element, that is absolutely conserved among eucaryotes. We report here the identification of HSF in the fission yeast Schizosaccharomyces pombe. HSF binding was not observed in extracts from normally growing S. pombe (28 degrees C) but was detected in increasing amounts as the temperature of heat shock increased between 39 and 45 degrees C. This regulation is in contrast to that observed in Saccharomyces cerevisiae, in which HSF binding is detectable at both normal and heat shock temperatures. The S. pombe factor bound specifically to the heat shock element, as judged by methylation interference and DNase I protection analysis. The induction of S. pombe HSF was not inhibited by cycloheximide, suggesting that induction occurs posttranslationally, and the induced factor was shown to be phosphorylated. S. pombe HSF was purified to near homogeneity and was shown to have an apparent mobility of approximately 108 kDa. Since heat-induced DNA binding by HSF had previously been demonstrated only in metazoans, the conservation of heat-induced DNA binding by HSF among S. pombe and metazoans suggests that this mode of regulation is evolutionarily ancient.

Thermal acclimation changes DNA-binding activity of heat shock factor 1(HSF1) in the gobyGillichthys mirabilis: implications for plasticity in the heat-shock response in natural populations

2002 ◽  
Vol 205 (20) ◽  
pp. 3231-3240 ◽  
Author(s):  
Bradley A. Buckley ◽  
Gretchen E. Hofmann
Keyword(s):  
Gene Expression ◽  
Heat Shock ◽  
Heat Shock Response ◽  
Environmental Control ◽  
Heat Shock Factor ◽  
Thermal Acclimation ◽  
Model Systems ◽  
Threshold Temperature ◽  
Heat Shock Factor 1 ◽  
Shock Response

SUMMARYThe intracellular build-up of thermally damaged proteins following exposure to heat stress results in the synthesis of a family of evolutionarily conserved proteins called heat shock proteins (Hsps) that act as molecular chaperones, protecting the cell against the aggregation of denatured proteins. The transcriptional regulation of heat shock genes by heat shock factor 1(HSF1) has been extensively studied in model systems, but little research has focused on the role HSF1 plays in Hsp gene expression in eurythermal organisms from broadly fluctuating thermal environments. The threshold temperature for Hsp induction in these organisms shifts with the recent thermal history of the individual but the mechanism by which this plasticity in Hsp induction temperature is achieved is unknown. We examined the effect of thermal acclimation on the heat-activation of HSF1 in the eurythermal teleost Gillichthys mirabilis. After a 5-week acclimation period (at 13, 21 or 28°C) the temperature of HSF1 activation was positively correlated with acclimation temperature. HSF1 activation peaked at 27°C in fish acclimated to 13°C, at 33°C in the 21°C group, and at 36°C in the 28°C group. Concentrations of both HSF1 and Hsp70 in the 28°C group were significantly higher than in the colder acclimated fish. Plasticity in HSF1 activation may be important to the adjustable nature of the heat shock response in eurythermal organisms and the environmental control of Hsp gene expression.

scholarly journals Alpha lipoic acid attenuates ER stress and improves glucose uptake through DNAJB3 cochaperone

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Abdoulaye Diane ◽  
Naela Mahmoud ◽  
Ilham Bensmail ◽  
Namat Khattab ◽  
Hanan A. Abunada ◽  
...  
Keyword(s):  
Heat Shock ◽  
Er Stress ◽  
Glucose Uptake ◽  
Lipoic Acid ◽  
Heat Shock Response ◽  
Transcriptional Activation ◽  
Hepg2 Cells ◽  
Metabolic Stress ◽  
C2c12 Cells ◽  
Shock Response

AbstractPersistent ER stress, mitochondrial dysfunction and failure of the heat shock response (HSR) are fundamental hallmarks of insulin resistance (IR); one of the early core metabolic aberrations that leads to type 2 diabetes (T2D). The antioxidant α-lipoic acid (ALA) has been shown to attenuate metabolic stress and improve insulin sensitivity in part through activation of the heat shock response (HSR). However, these studies have been focused on a subset of heat shock proteins (HSPs). In the current investigation, we assessed whether ALA has an effect on modulating the expression of DNAJB3/HSP40 cochaperone; a potential therapeutic target with a novel role in mitigating metabolic stress and promoting insulin signaling. Treatment of C2C12 cells with 0.3 mM of ALA triggers a significant increase in the expression of DNAJB3 mRNA and protein. A similar increase in DNAJB3 mRNA was also observed in HepG2 cells. We next investigated the significance of such activation on endoplasmic reticulum (ER) stress and glucose uptake. ALA pre-treatment significantly reduced the expression of ER stress markers namely, GRP78, XBP1, sXBP1 and ATF4 in response to tunicamycin. In functional assays, ALA treatment abrogated significantly the tunicamycin-mediated transcriptional activation of ATF6 while it enhanced the insulin-stimulated glucose uptake and Glut4 translocation. Silencing the expression of DNAJB3 but not HSP72 abolished the protective effect of ALA on tunicamycin-induced ER stress, suggesting thus that DNAJB3 is a key mediator of ALA-alleviated tunicamycin-induced ER stress. Furthermore, the effect of ALA on insulin-stimulated glucose uptake is significantly reduced in C2C12 and HepG2 cells transfected with DNAJB3 siRNA. In summary, our results are supportive of an essential role of DNAJB3 as a molecular target through which ALA alleviates ER stress and improves glucose uptake.

scholarly journals Inhibition of the activation of heat shock factor in vivo and in vitro by flavonoids.

1992 ◽  
Vol 12 (8) ◽  
pp. 3490-3498 ◽  
Author(s):  
N Hosokawa ◽  
K Hirayoshi ◽  
H Kudo ◽  
H Takechi ◽  
A Aoike ◽  
...  
Keyword(s):  
Heat Shock ◽  
Transcriptional Activation ◽  
Heat Shock Factor ◽  
Mobility Shift ◽  
Human Colon Cancer ◽  
Heat Shock Element ◽  
Mrna Accumulation ◽  
Cell Extracts

Transcriptional activation of human heat shock protein (HSP) genes by heat shock or other stresses is regulated by the activation of a heat shock factor (HSF). Activated HSF posttranslationally acquires DNA-binding ability. We previously reported that quercetin and some other flavonoids inhibited the induction of HSPs in HeLa and COLO 320DM cells, derived from a human colon cancer, at the level of mRNA accumulation. In this study, we examined the effects of quercetin on the induction of HSP70 promoter-regulated chloramphenicol acetyltransferase (CAT) activity and on the binding of HSF to the heat shock element (HSE) by a gel mobility shift assay with extracts of COLO 320DM cells. Quercetin inhibited heat-induced CAT activity in COS-7 and COLO 320DM cells which were transfected with plasmids bearing the CAT gene under the control of the promoter region of the human HSP70 gene. Treatment with quercetin inhibited the binding of HSF to the HSE in whole-cell extracts activated in vivo by heat shock and in cytoplasmic extracts activated in vitro by elevated temperature or by urea. The binding of HSF activated in vitro by Nonidet P-40 was not suppressed by the addition of quercetin. The formation of the HSF-HSE complex was not inhibited when quercetin was added only during the binding reaction of HSF to the HSE after in vitro heat activation. Quercetin thus interacts with HSF and inhibits the induction of HSPs after heat shock through inhibition of HSF activation.

Sign in / Sign up

Export Citation Format

Share Document