Quantitative proteomics identifies the universally conserved ATPase Ola1p as a positive regulator of heat shock response in Saccharomyces cerevisiae

The universally conserved P-loop ATPase Ola1 is implicated in various cellular stress response pathways, as well as in cancer and tumor progression. However, Ola1p functions are divergent between species and the involved mechanisms are only poorly understood. Here, we studied the role of Ola1p in the heat shock response of the yeast Saccharomyces cerevisiae using a combination of quantitative and pulse labeling-based proteomics approaches, in vitro studies and cell-based assays. Our data show that when heat stress is applied to cells lacking Ola1p, the expression of stress-protective proteins is enhanced. During heat stress Ola1p associates with detergent-resistant protein aggregates and rapidly forms assemblies that localize to stress granules. The assembly of Ola1p was also observed in vitro using purified protein and conditions, which resembled those in living cells. We show that loss of Ola1p results in increased protein ubiquitination of detergent-insoluble aggregates recovered from heat-shocked cells. When subsequently cells lacking Ola1p were relieved from heat stress, reinitiation of translation was delayed, whereas, at the same time, de novo synthesis of central factors required for protein refolding and the clearance of aggregates was enhanced when compared to wildtype cells. The combined data suggest that upon acute heat stress, Ola1p is involved in the stabilization of misfolded proteins, which become sequestered in cytoplasmic stress granules. This function of Ola1p enables cells to resume translation in a timely manner as soon as heat stress is relieved.

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The Heat-Shock Response and Expression of Heat-Shock Proteins in Wheat Under Diurnal Heat Stress and Field Conditions

Functional Plant Biology ◽

10.1071/pp9940857 ◽

1994 ◽

Vol 21 (6) ◽

pp. 857 ◽

Cited By ~ 14

Author(s):

HT Nguyen ◽

CP Joshi ◽

N Klueva ◽

J Weng ◽

KL Hendershot ◽

...

Keyword(s):

Heat Stress ◽

Heat Shock ◽

Heat Shock Proteins ◽

Heat Tolerance ◽

Heat Shock Response ◽

Field Conditions ◽

Shock Response ◽

Heat Tolerant ◽

Shock Proteins

The occurrence of heat-shock proteins (HSPs) in response to high temperature stress is a universal phenomenon in higher plants and has been well documented. However, in agriculturally important species, less is known about the expression of HSPs under natural environments. A review of the heat-shock response in wheat (Triticum aestivum L.) is presented and recent results on the expression of wheat HSPs under diurnal stress and field conditions are reported. In the field experiment, flag leaf blade temperatures were obtained and leaf blades collected for northern blot analysis using HSP 16.9 cDNA as a probe. Temperatures of leaf blades ranged from 32 to 35�C under the tested field conditions at New Deal near Lubbock, Texas. Messenger RNAs encoding a major class of low molecular weight HSPs, HSP 16.9, were detected in all wheat genotypes examined. The results suggested that HSPs are synthesised in response to heat stress under agricultural production, and furthermore, that HSPs are produced in wheats differing in geographic background. In the controlled growth chamber experiment, HSP expression in two wheat cultivars, Mustang (heat tolerant) and Sturdy (heat susceptible) were analysed to determine if wheat genotypes differing in heat tolerance differ in in vitro HSP synthesis (translatable HSP mRNAs) under a chronic, diurnal heat-stress regime. Leaf tissues were collected from seedlings over a time-course and poly (A)+RNAs were isolated for in vitro translation and 2-D gel electrophoresis. The protein profiles shown in the 2-D gel analysis revealed that there were not only quantitative differences of individual HSPs between these two wheat lines, but also some unique HSPs which were only found in the heat tolerant line. This data provides evidence of a correlation between HSP synthesis and heat tolerance in wheat under a simulated field environment and suggests that further genetic analysis of HSPs in a segregating population is worthy of investigation. In conclusion, the results of this study provide an impetus for the investigation of the roles of HSP genes in heat tolerance in wheat.

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Efficient Heat Shock Response Affects Hyperthermia-Induced Radiosensitization in a Tumor Spheroid Control Probability Assay

Cancers ◽

10.3390/cancers13133168 ◽

2021 ◽

Vol 13 (13) ◽

pp. 3168

Author(s):

Oleg Chen ◽

Soňa Michlíková ◽

Lisa Eckhardt ◽

Marit Wondrak ◽

Adriana M. De Mendoza ◽

...

Keyword(s):

Stress Response ◽

Heat Shock ◽

Heat Shock Response ◽

Cellular Stress Response ◽

Proteotoxic Stress ◽

Shock Response ◽

Pre Treatment ◽

Shock Proteins ◽

The Impact

Hyperthermia (HT) combined with irradiation is a well-known concept to improve the curative potential of radiotherapy. Technological progress has opened new avenues for thermoradiotherapy, even for recurrent head and neck squamous cell carcinomas (HNSCC). Preclinical evaluation of the curative radiosensitizing potential of various HT regimens remains ethically, economically, and technically challenging. One key objective of our study was to refine an advanced 3-D assay setup for HT + RT research and treatment testing. For the first time, HT-induced radiosensitization was systematically examined in two differently radioresponsive HNSCC spheroid models using the unique in vitro “curative” analytical endpoint of spheroid control probability. We further investigated the cellular stress response mechanisms underlying the HT-related radiosensitization process with the aim to unravel the impact of HT-induced proteotoxic stress on the overall radioresponse. HT disrupted the proteome’s thermal stability, causing severe proteotoxic stress. It strongly enhanced radiation efficacy and affected paramount survival and stress response signaling networks. Transcriptomics, q-PCR, and western blotting data revealed that HT + RT co-treatment critically triggers the heat shock response (HSR). Pre-treatment with chemical chaperones intensified the radiosensitizing effect, thereby suppressing HT-induced Hsp27 expression. Our data suggest that HT-induced radiosensitization is adversely affected by the proteotoxic stress response. Hence, we propose the inhibition of particular heat shock proteins as a targeting strategy to improve the outcome of combinatorial HT + RT.

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Comparative studies between the glucose-induced phosphorylation signal and the heat shock response in mutants of Saccharomyces cerevisiae

Biochimie ◽

10.1016/0300-9084(89)90002-3 ◽

1989 ◽

Vol 71 (3) ◽

pp. 313-318 ◽

Cited By ~ 12

Author(s):

Anita D. Panek ◽

Renato Ferreira ◽

Ana C. Panek

Keyword(s):

Saccharomyces Cerevisiae ◽

Heat Shock ◽

Heat Shock Response ◽

Comparative Studies ◽

Shock Response

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Molecular Basis of the Defective Heat Stress Response in Mycobacterium leprae

Journal of Bacteriology ◽

10.1128/jb.00601-07 ◽

2007 ◽

Vol 189 (24) ◽

pp. 8818-8827 ◽

Cited By ~ 15

Author(s):

Diana L. Williams ◽

Tana L. Pittman ◽

Mike Deshotel ◽

Sandra Oby-Robinson ◽

Issar Smith ◽

...

Keyword(s):

Heat Stress ◽

Stress Response ◽

Heat Shock ◽

Heat Shock Response ◽

Elevated Temperatures ◽

Transcriptional Response ◽

Mycobacterium Leprae ◽

Heat Stress Response ◽

Regulatory Circuits ◽

Shock Response

ABSTRACT Mycobacterium leprae, a major human pathogen, grows poorly at 37°C. The basis for its inability to survive at elevated temperatures was investigated. We determined that M. leprae lacks a protective heat shock response as a result of the lack of transcriptional induction of the alternative sigma factor genes sigE and sigB and the major heat shock operons, HSP70 and HSP60, even though heat shock promoters and regulatory circuits for these genes appear to be intact. M. leprae sigE was found to be capable of complementing the defective heat shock response of mycobacterial sigE knockout mutants only in the presence of a functional mycobacterial sigH, which orchestrates the mycobacterial heat shock response. Since the sigH of M. leprae is a pseudogene, these data support the conclusion that a key aspect of the defective heat shock response in M. leprae is the absence of a functional sigH. In addition, 68% of the genes induced during heat shock in M. tuberculosis were shown to be either absent from the M. leprae genome or were present as pseudogenes. Among these is the hsp/acr2 gene, whose product is essential for M. tuberculosis survival during heat shock. Taken together, these results suggest that the reduced ability of M. leprae to survive at elevated temperatures results from the lack of a functional transcriptional response to heat shock and the absence of a full repertoire of heat stress response genes, including sigH.

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Sub-lethal heat stress causes apoptosis in an Antarctic fish that lacks an inducible heat shock response

Journal of Thermal Biology ◽

10.1016/j.jtherbio.2014.06.007 ◽

2014 ◽

Vol 44 ◽

pp. 119-125 ◽

Cited By ~ 9

Author(s):

Isaac M. Sleadd ◽

Marissa Lee ◽

Daniel O. Hassumani ◽

Tonya M.A. Stecyk ◽

Otto K. Zeitz ◽

...

Keyword(s):

Heat Stress ◽

Heat Shock ◽

Heat Shock Response ◽

Antarctic Fish ◽

Shock Response

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

Molecular and Cellular Biology ◽

10.1128/mcb.11.1.281 ◽

1991 ◽

Vol 11 (1) ◽

pp. 281-288 ◽

Cited By ~ 35

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.

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