Over-expression of LlHsfA2b, a lily heat shock transcription factor lacking trans-activation activity in yeast, can enhance tolerance to heat and oxidative stress in transgenic Arabidopsis seedlings

ABSTRACT The heat shock transcription factor Hsf1 of the yeast Saccharomyces cerevisiae regulates the transcription of a set of genes that contain heat shock elements (HSEs) in their promoters and function in diverse cellular processes, including protein folding. Here, we show that Hsf1 activates the transcription of various target genes when cells are treated with oxidizing reagents, including the superoxide anion generators menadione and KO2 and the thiol oxidants diamide and 1-chloro-2,4-dinitrobenzene (CDNB). Similar to heat shock, the oxidizing reagents are potent inducers of both efficient HSE binding and extensive phosphorylation of Hsf1. The inducible phosphorylation of Hsf1 is regulated by the intramolecular domain-domain interactions and affects HSE structure-specific transcription. Unlike the heat shock, diamide, or CDNB response, menadione or KO2 activation of Hsf1 is inhibited by cyclic-AMP-dependent protein kinase (PKA) activity, which negatively regulates the activator functions of other transcriptional regulators implicated in the oxidative stress response. These results demonstrate that Hsf1 is a member of the oxidative stress-responsive activators and that PKA is a general negative regulator in the superoxide anion response.

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The heat shock transcription factor HSF-1 protects Caenorhabditis elegans from peroxide stress

10.1101/2020.07.13.200634 ◽

2020 ◽

Author(s):

Francesco A. Servello ◽

Javier Apfeld

Keyword(s):

Oxidative Stress ◽

Transcription Factor ◽

Caenorhabditis Elegans ◽

Heat Shock ◽

Defense Mechanisms ◽

Heat Shock Transcription Factor ◽

Transactivation Domain ◽

C Elegans ◽

Multicellular Organisms ◽

Mild Temperature

AbstractCells induce conserved defense mechanisms that protect them from oxidative stress. How these defenses are regulated in multicellular organisms is incompletely understood. Using the nematode Caenorhabditis elegans, we show that the heat shock transcription factor HSF-1 protects the nematode from the oxidative stress induced by environmental peroxide. In response to a heat shock or a mild temperature increase, HSF-1 protects the nematodes from subsequent oxidative stress in a manner that depends on HSF-1’s transactivation domain. At constant temperature, HSF-1 protects the nematodes from oxidative stress independently of its transactivation domain, likely by inducing the expression of asp-4/cathepsin D and dapk-1/dapk. Thus, two distinct HSF-1-dependent processes protect C. elegans from oxidative stress.

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The heat shock transcription factor PsHSF1 ofPhytophthora sojaeis required for oxidative stress tolerance and detoxifying the plant oxidative burst

Environmental Microbiology ◽

10.1111/1462-2920.12609 ◽

2014 ◽

Vol 17 (4) ◽

pp. 1351-1364 ◽

Cited By ~ 11

Author(s):

Yuting Sheng ◽

Yonglin Wang ◽

Harold J. G. Meijer ◽

Xinyu Yang ◽

Chenlei Hua ◽

...

Keyword(s):

Oxidative Stress ◽

Transcription Factor ◽

Heat Shock ◽

Stress Tolerance ◽

Oxidative Burst ◽

Heat Shock Transcription Factor ◽

Oxidative Stress Tolerance

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Expression of maize heat shock transcription factor gene ZmHsf06 enhances the thermotolerance and drought-stress tolerance of transgenic Arabidopsis

Functional Plant Biology ◽

10.1071/fp15080 ◽

2015 ◽

Vol 42 (11) ◽

pp. 1080 ◽

Cited By ~ 16

Author(s):

Hui-cong Li ◽

Hua-ning Zhang ◽

Guo-liang Li ◽

Zi-hui Liu ◽

Yan-min Zhang ◽

...

Keyword(s):

Transcription Factor ◽

Drought Stress ◽

Heat Shock ◽

Stress Tolerance ◽

Transgenic Arabidopsis ◽

Germination Rate ◽

Heat Shock Transcription Factor ◽

Drought Stress Tolerance ◽

Acquired Thermotolerance ◽

A Genome

Based on the information of 25 heat shock transcription factor (Hsf) homologues in maize according to a genome-wide analysis, ZmHsf06 was cloned from maize leaves and transformed into Arabidopsis thaliana (L. Heynh.) (ecotype, Col-0). Three transgenic positive lines were selected to assess the basic and acquired thermotolerance and drought-stress tolerance under stresses and for some physiological assays. The sequence analysis indicates that ZmHsf06 contained the characteristic domains of class A type plant Hsfs. The results of qRT–PCR showed that the expression levels of ZmHsf06 were elevated by heat shock and drought stress to different extents in three transgenic lines. Phenotypic observation shows that compared with the Wt (wild-type) controls, the overexpressing ZmHsf06 of Arabidopsis plants have enhanced basal and acquired thermotolerance, stronger drought-stress tolerance and growth advantages under mild heat stress conditions. These results are further confirmed by physiological and biochemical evidence that transgenic Arabidopsis plants exhibit higher seed germination rate, longer axial-root length, higher activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), higher leaf chlorophyll content, but lower relative electrical conductivity (REC), malondialdehyde (MDA) and osmotic potential (OP) than the Wt controls after heat shock and drought treatments. ZmHsf06 may be a central representative of maize Hsfs and could be useful in molecular breeding of maize or other crops for enhanced tolerances, particularly during terminal heat and drought stresses.

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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.

Molecular and Cellular Biology ◽

10.1128/mcb.14.11.7557 ◽

1994 ◽

Vol 14 (11) ◽

pp. 7557-7568 ◽

Cited By ~ 126

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.

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