scholarly journals Cloning and characterization of two mouse heat shock factors with distinct inducible and constitutive DNA-binding ability.

1991 ◽  
Vol 5 (10) ◽  
pp. 1902-1911 ◽  
Author(s):  
K D Sarge ◽  
V Zimarino ◽  
K Holm ◽  
C Wu ◽  
R I Morimoto
Keyword(s):  
Heat Shock ◽  
Dna Binding ◽  
Heat Shock Factors ◽  
Binding Ability

scholarly journals Activation of the DNA-binding ability of human heat shock transcription factor 1 may involve the transition from an intramolecular to an intermolecular triple-stranded coiled-coil structure.

1994 ◽  
Vol 14 (11) ◽  
pp. 7557-7568 ◽  
Author(s):  
J Zuo ◽  
R Baler ◽  
G Dahl ◽  
R Voellmy
Keyword(s):  
Transcription Factor ◽  
Heat Stress ◽  
Heat Shock ◽  
Dna Binding ◽  
Hydrophobic Interactions ◽  
Coiled Coil ◽  
Heat Shock Transcription Factor ◽  
Single Amino Acid ◽  
Binding Ability ◽  
Heat Shock Element

Heat stress regulation of human heat shock genes is mediated by human heat shock transcription factor hHSF1, which contains three 4-3 hydrophobic repeats (LZ1 to LZ3). In unstressed human cells (37 degrees C), hHSF1 appears to be in an inactive, monomeric state that may be maintained through intramolecular interactions stabilized by transient interaction with hsp70. Heat stress (39 to 42 degrees C) disrupts these interactions, and hHSF1 homotrimerizes and acquires heat shock element DNA-binding ability. hHSF1 expressed in Xenopus oocytes also assumes a monomeric, non-DNA-binding state and is converted to a trimeric, DNA-binding form upon exposure of the oocytes to heat shock (35 to 37 degrees C in this organism). Because endogenous HSF DNA-binding activity is low and anti-hHSF1 antibody does not recognize Xenopus HSF, we employed this system for mapping regions in hHSF1 that are required for the maintenance of the monomeric state. The results of mutagenesis analyses strongly suggest that the inactive hHSF1 monomer is stabilized by hydrophobic interactions involving all three leucine zippers which may form a triple-stranded coiled coil. Trimerization may enable the DNA-binding function of hHSF1 by facilitating cooperative binding of monomeric DNA-binding domains to the heat shock element motif. This view is supported by observations that several different LexA DNA-binding domain-hHSF1 chimeras bind to a LexA-binding site in a heat-regulated fashion, that single amino acid replacements disrupting the integrity of hydrophobic repeats render these chimeras constitutively trimeric and DNA binding, and that LexA itself binds stably to DNA only as a dimer but not as a monomer in our assays.

Activation of the DNA-binding ability of human heat shock transcription factor 1 may involve the transition from an intramolecular to an intermolecular triple-stranded coiled-coil structure

1994 ◽  
Vol 14 (11) ◽  
pp. 7557-7568
Author(s):  
J Zuo ◽  
R Baler ◽  
G Dahl ◽  
R Voellmy
Keyword(s):  
Transcription Factor ◽  
Heat Stress ◽  
Heat Shock ◽  
Dna Binding ◽  
Hydrophobic Interactions ◽  
Coiled Coil ◽  
Heat Shock Transcription Factor ◽  
Single Amino Acid ◽  
Binding Ability ◽  
Heat Shock Element

Heat stress regulation of human heat shock genes is mediated by human heat shock transcription factor hHSF1, which contains three 4-3 hydrophobic repeats (LZ1 to LZ3). In unstressed human cells (37 degrees C), hHSF1 appears to be in an inactive, monomeric state that may be maintained through intramolecular interactions stabilized by transient interaction with hsp70. Heat stress (39 to 42 degrees C) disrupts these interactions, and hHSF1 homotrimerizes and acquires heat shock element DNA-binding ability. hHSF1 expressed in Xenopus oocytes also assumes a monomeric, non-DNA-binding state and is converted to a trimeric, DNA-binding form upon exposure of the oocytes to heat shock (35 to 37 degrees C in this organism). Because endogenous HSF DNA-binding activity is low and anti-hHSF1 antibody does not recognize Xenopus HSF, we employed this system for mapping regions in hHSF1 that are required for the maintenance of the monomeric state. The results of mutagenesis analyses strongly suggest that the inactive hHSF1 monomer is stabilized by hydrophobic interactions involving all three leucine zippers which may form a triple-stranded coiled coil. Trimerization may enable the DNA-binding function of hHSF1 by facilitating cooperative binding of monomeric DNA-binding domains to the heat shock element motif. This view is supported by observations that several different LexA DNA-binding domain-hHSF1 chimeras bind to a LexA-binding site in a heat-regulated fashion, that single amino acid replacements disrupting the integrity of hydrophobic repeats render these chimeras constitutively trimeric and DNA binding, and that LexA itself binds stably to DNA only as a dimer but not as a monomer in our assays.

Protein substrates and heat shock reduce the DNA-binding ability of Escherichia coli Lon protease

1995 ◽  
Vol 44 (3-4) ◽  
pp. 484-488 ◽  
Author(s):  
S. Sonezaki ◽  
K. Okita ◽  
T. Oba ◽  
Y. Ishii ◽  
A. Kondo ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Heat Shock ◽  
Dna Binding ◽  
Lon Protease ◽  
Binding Ability ◽  
Protein Substrates

scholarly journals Inhibition of DNA Binding by Differential Sumoylation of Heat Shock Factors

2006 ◽  
Vol 26 (3) ◽  
pp. 955-964 ◽  
Author(s):  
Julius Anckar ◽  
Ville Hietakangas ◽  
Konstantin Denessiouk ◽  
Dennis J. Thiele ◽  
Mark S. Johnson ◽  
...  
Keyword(s):  
Heat Shock ◽  
Dna Binding ◽  
Regulation Of Gene Expression ◽  
Binding Activity ◽  
Covalent Modification ◽  
Heat Shock Factors ◽  
Substrate Selection ◽  
Binding Domains ◽  
Dna Binding Activity ◽  
Specific Regulation

ABSTRACT Covalent modification of proteins by the small ubiquitin-related modifier SUMO regulates diverse biological functions. Sumoylation usually requires a consensus tetrapeptide, through which the binding of the SUMO-conjugating enzyme Ubc9 to the target protein is directed. However, additional specificity determinants are in many cases required. To gain insights into SUMO substrate selection, we have utilized the differential sumoylation of highly similar loop structures within the DNA-binding domains of heat shock transcription factor 1 (HSF1) and HSF2. Site-specific mutagenesis in combination with molecular modeling revealed that the sumoylation specificity is determined by several amino acids near the consensus site, which are likely to present the SUMO consensus motif to Ubc9. Importantly, we also demonstrate that sumoylation of the HSF2 loop impedes HSF2 DNA-binding activity, without affecting its oligomerization. Hence, SUMO modification of the HSF2 loop contributes to HSF-specific regulation of DNA binding and broadens the concept of sumoylation in the negative regulation of gene expression.

Family-wide Characterization of methylated DNA Binding Ability of Arabidopsis MBDs

2021 ◽  
pp. 167404
Author(s):  
Zhibin Wu ◽  
Sizhuo Chen ◽  
Mengqi Zhou ◽  
Lingbo Jia ◽  
Zhenhua Li ◽  
...  
Keyword(s):  
Dna Binding ◽  
Binding Ability ◽  
Methylated Dna

scholarly journals The DNA-binding properties of two heat shock factors, HSF1 and HSF3, are induced in the avian erythroblast cell line HD6.

1995 ◽  
Vol 15 (10) ◽  
pp. 5268-5278 ◽  
Author(s):  
A Nakai ◽  
Y Kawazoe ◽  
M Tanabe ◽  
K Nagata ◽  
R I Morimoto
Keyword(s):  
Heat Shock ◽  
Dna Binding ◽  
Cell Line ◽  
Biological Properties ◽  
Binding Activity ◽  
Heat Shock Factors ◽  
Reporter Construct ◽  
Heat Shock Element ◽  
Dna Binding Activity ◽  
Dna Binding Properties

Avian cells express three heat shock transcription factor (HSF) genes corresponding to a novel factor, HSF3, and homologs of mouse and human HSF1 and HSF2. Analysis of the biochemical and cell biological properties of these HSFs reveals that HSF3 has properties in common with both HSF1 and HSF2 and yet has features which are distinct from both. HSF3 is constitutively expressed in the erythroblast cell line HD6, the lymphoblast cell line MSB, and embryo fibroblasts, and yet its DNA-binding activity is induced only upon exposure of HD6 cells to heat shock. Acquisition of HSF3 DNA-binding activity in HD6 cells is accompanied by oligomerization from a non-DNA-binding dimer to a DNA-binding trimer, whereas the effect of heat shock on HSF1 is oligomerization of an inert monomer to a DNA-binding trimer. Induction of HSF3 DNA-binding activity is delayed compared with that of HSF1. As occurs for HSF1, heat shock leads to the translocation of HSF3 to the nucleus. HSF exhibits the properties of a transcriptional activator, as judged from the stimulatory activity of transiently overexpressed HSF3 measured by using a heat shock element-containing reporter construct and as independently assayed by the activity of a chimeric GAL4-HSF3 protein on a GAL4 reporter construct. These results reveal that HSF3 is negatively regulated in avian cells and acquires DNA-binding activity in certain cells upon heat shock.

scholarly journals Stress-Specific Activation and Repression of Heat Shock Factors 1 and 2

2001 ◽  
Vol 21 (21) ◽  
pp. 7163-7171 ◽  
Author(s):  
Anu Mathew ◽  
Sameer K. Mathur ◽  
Caroline Jolly ◽  
Susan G. Fox ◽  
Soojin Kim ◽  
...  
Keyword(s):  
Heat Shock ◽  
Dna Binding ◽  
Heat Shock Proteins ◽  
Heat Shock Gene ◽  
Heat Shock Factors ◽  
Reversible Inactivation ◽  
Acid Analogue ◽  
Heat Shock Gene Expression ◽  
Shock Proteins ◽  
Different Levels

ABSTRACT Vertebrate cells express a family of heat shock transcription factors (HSF1 to HSF4) that coordinate the inducible regulation of heat shock genes in response to diverse signals. HSF1 is potent and activated rapidly though transiently by heat shock, whereas HSF2 is a less active transcriptional regulator but can retain its DNA binding properties for extended periods. Consequently, the differential activation of HSF1 and HSF2 by various stresses may be critical for cells to survive repeated and diverse stress challenges and to provide a mechanism for more precise regulation of heat shock gene expression. Here we show, using a novel DNA binding and detection assay, that HSF1 and HSF2 are coactivated to different levels in response to a range of conditions that cause cell stress. Above a low basal activity of both HSFs, heat shock preferentially activates HSF1, whereas the amino acid analogue azetidine or the proteasome inhibitor MG132 coactivates both HSFs to different levels and hemin preferentially induces HSF2. Unexpectedly, we also found that heat shock has dramatic adverse effects on HSF2 that lead to its reversible inactivation coincident with relocalization from the nucleus. The reversible inactivation of HSF2 is specific to heat shock and does not occur with other stressors or in cells expressing high levels of heat shock proteins. These results reveal that HSF2 activity is negatively regulated by heat and suggest a role for heat shock proteins in the positive regulation of HSF2.

scholarly journals Molecular Characterization of Heat-Induced HSP11.0 and Master-Regulator HSF from Cotesia chilonis and Their Consistent Response to Heat Stress

Insects ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 322
Author(s):  
Fu-Jing He ◽  
Feng Zhu ◽  
Ming-Xing Lu ◽  
Yu-Zhou Du
Keyword(s):  
Heat Shock ◽  
Temperature Stress ◽  
Heptad Repeat ◽  
Heat Shock Factors ◽  
Master Regulator ◽  
Real Time Quantitative Pcr ◽  
Shock Proteins ◽  
Consistent Response ◽  
Cotesia Chilonis

Small heat shock proteins (sHSPs) are members of the heat shock protein (HSP) family that play an important role in temperature stress, and heat shock factors (HSFs) are transcriptional activators that regulate HSP expression. Cotesia chilonis, the major endoparasitoid of Chilo suppressalis, modulates the C. suppressalis population in the field. In this study, we cloned and characterized two genes from C.chilonis: the heat-induced HSP11.0 gene (Cchsp11.0) that consisted of a 306-bp ORF, and the master regulator HSF (Cchsf) containing an 1875-bp ORF. CcHSP11.0 contained a chaperonin cpn10 signature motif that is conserved in other hymenopteran insects. CcHSF is a typical HSF and contains a DNA-binding domain, two hydrophobic heptad repeat domains, and a C-terminal trans-activation domain. Neither Cchsp11.0 or Cchsf contain introns. Real-time quantitative PCR revealed that Cchsp11.0 and Cchsf were highly induced at 36 °C and 6 °C after a 2-h exposure. Overall, the induction of Cchsf was lower than Cchsp11.0 at low temperatures, whereas the opposite was true at high temperatures. In conclusion, both Cchsp11.0 and Cchsf are sensitive to high and low temperature stress, and the expression pattern of the two genes were positively correlated during temperature stress.

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