• Development and Reproduction
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• v.14 no.3
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• pp.179-184
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• 2010

Water temperature influences on various key biological events in fish, but the internal pathway of the temperature effects are not well understood. Heat shock proteins (HSPs), known to respond in the level of cells to many environmental factors including temperature, could improve our understanding on the pathway. Some biological processes such as gonadal development and sex differentiation in the Nile tilapia Oreochromis niloticus is particularly sensitive to water temperature. In this study, we have investigated the expressions of HSP70 and HSP90 genes in young tilapia at an ordinary temperature ($28^{\circ}C$) and elevated water temperature ($36^{\circ}C$). The distribution of the expressions of HSP70 and HSP90 mRNA in this species were found to be almost ubiquitous, being detected in all tissues studied here (brain, gonad, liver and muscle), suggesting the house keeping functions of these genes. Heat shock by elevating temperature from $28^{\circ}C$ to $36^{\circ}C$ significantly increased the expression of HSP70 mRNA in the gonad, liver and muscle for several hours (P<0.05) (brain tissue was not examined for this). The increased level of HSP70 gene expression recovered to the level at control temperature ($28^{\circ}C$) when fish were kept continuously at high temperature ($36^{\circ}C$) for 24 hours. Contrary to this, expression of HSP90 mRNA did not show significant increase in the gonad and muscle by the same heat shock (P>0.05), except in the liver where the expression of HSP90 mRNA increased continuously for 24 hours at $36^{\circ}C$. The results obtained in this study suggest that response to temperature change in different tissue or organ may utilize different heat shock proteins, and that HSP70 may have some importance in temperature-sensitive gonadal event in the Nile tilapia.

• BMB Reports
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• v.31 no.2
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• pp.201-208
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• 1998

Amino acid analogs, like other inducers of stress response, induce the synthesis of stress proteins in mammalian cells. In this study, Drosophila Kc cells, in which translation is tightly controlled during stress response, was treated with proline analogs, L-azetidine-2-carboxylic acid (AzC) and 3,4-dehydro-L-proline (dh-P). Kc cells exposed to AzC or dh-P induced the synthesis of several proteins which had the same molecular weights as known heat shock proteins. However, in Kc cells, normal protein synthesis still continued in the presence of amino acids analogs unlike in heat-shocked cells. For the induction of stress response, the incorporation of dh-P into the protein was not essential, but the incorporation of AzC was. The stress protein synthesis was regulated mainly at the transcriptional level by AzC, whereas it was regulated by dh-P at the transcription level and possibly posttranscription level. During recovery, the stress protein synthesis stopped sooner in analog-treated cells than in heat-shocked cells even though the accumulated amount of Hsp70 was much less in proline analogstreated cells. It could be concluded that the proline analogs, AzC and dh-P, induced stress response through a different mechanism from heat shock.

• The Zoological Society Korea : Newsletter
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• v.12 no.2
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• pp.113.2-113
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• 1995

No Abstract, See Full Text

• Proceedings of the Zoological Society Korea Conference
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• 1995.10b
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• pp.249.2-249
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• 1995

No Abstract, See Full Text

• Journal of The Korean Society of Grassland and Forage Science
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• v.31 no.2
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• pp.99-106
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• 2011

In order to investigate rice stem proteome in response to heat stress, rice plants were subjected to heat treatment at 42$^{\circ}C$ and total soluble proteins were extracted from stem tissues, and were fractionated with 15% PEG (poly ethylene glycol) and separated by two-dimensional polyacrylamide gel electrophoresis (2-DE). After staining of 2-DE gels, 46 of differentially expressed proteins were extracted, digested by trypsin, and subjected to matrix assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) analysis. Proteins were identified through database search by using peptide mass fingerprints. Among them, 10 proteins were successfully identified. Seven proteins were up- and 3 proteins were down-regulated, respectively. These proteins are involved in energy and metabolism, redox homeostasis, and mitochondrial small heat shock proteins. The identification of some novel proteins in the heat stress response provides new insights that can lead to a better understanding of the molecular basis of heat-sensitivity in plants, and also useful to molecular breeding of thermotolerant forage crops.

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.911-911
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• 2005

• Journal of Microbiology and Biotechnology
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• v.10 no.2
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• pp.137-142
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• 2000

Environmental stres is known to induce heat shock proteins (HSPs) in eukaryotic cells. However, the induction of HSPs in host cells by microbial infection has not yet been well explained. Staphylococcus aureus (S. aureus) is one of the major pathogens in the pathogenesis of endovascular diseases such as infective endocarditis. In this study, the synthesis of stress-inducible 70 kDa HSP was investigated in the endothelial cells (ECs) after 3 h to 20 h of incubation with S. aureus. The dffect of S. aureus infection on the expression of HSP70 in cultured ECs was analyzed using laser scanning confocal microscopy (LSCM). The increase of HSP70 expression in ECs infected by S. aureus ($10^4{\;}cfu/ml$) for 20 h was 1.1-fold higher than that in heat shock treated ECs and 2.2-fold higher than that in untreated cells. Heat shock is known to induce intranucleus HSP70 expression in mammalian cells, whereas the S. aureus infection induced perinuclear expression in ECs as observed by LSCM. Consequently, the expression of HSP70 in ECs plays an important role in the pathogenesis of endovascular infection.

• Korean Journal of Microbiology
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• v.37 no.3
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• pp.221-227
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• 2001

Heat shock proteins serve as chaperone by preventing the aggregation of denatured proteins and promote survival of pathogens in harsh environments. In bacteria, ethanol shock induced the major chaperone GroEL and DnaK, but in Streptococcus pneumoniae, it induced neither GroEL nor DnaK but alcohol dehydrogenase (ADH). In this study, ADH gene encoding a 104-kDa (p104) protein was identified and characterized. The deduced amino acid sequence of pneumococcal ADH shows homology with other members of the ADH family, and particularly with Entamoeba histolytica ADH2 and E. coli ADH. S. pneumoniae adh is composed of 883 amino acids and its estimated isoelectric point is 6.09. Although ADH is conserved between S. pneumoniae and E. coli, immunoblot analysis employing antisera raised against pneumococcus ADH demonstrated no cross-reactivity with ADH analog in Eschericha coli, Staphylococcus aureus and human HeLa cells. Also secretion of ADH was demonstrated by subcellular fractionation and immunoblot analysis of proteins. These results suggest that S. pneumoniae ADH could be a highly feasible candidate for both diagnostic marker and vaccine.

• Journal of Microbiology and Biotechnology
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• v.24 no.8
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• pp.1118-1122
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• 2014

The present study shows that DR1114 (Hsp20), a small heat shock protein of the radiation-resistant bacterium Deinococcus radiodurans, enhances tolerance to hydrogen peroxide ($H_2O_2$) stress when expressed in Escherichia coli. A protein profile comparison showed that E. coli cells overexpressing D. radiodurans Hsp20 (EC-pHsp20) activated the redox state proteins, thus maintaining redox homeostasis. The cells also showed increased expression of pseudouridine (psi) synthases, which are important to the stability and proper functioning of structural RNA molecules. We found that the D. radiodurans mutant strain, which lacks a psi synthase (DR0896), was more sensitive to $H_2O_2$ stress than wild type. These suggest that an increased expression of proteins involved in the control of redox state homeostasis along with more stable ribosomal function may explain the improved tolerance of EC-pHsp20 to $H_2O_2$ stress.

• Molecules and Cells
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• v.39 no.2
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• pp.163-168
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• 2016

Caffeine has both positive and negative effects on physiological functions in a dose-dependent manner. C. elegans has been used as an animal model to investigate the effects of caffeine on development. Caffeine treatment at a high dose (30 mM) showed detrimental effects and caused early larval arrest. We performed a comparative proteomic analysis to investigate the mode of action of high-dose caffeine treatment in C. elegans and found that the stress response proteins, heat shock protein (HSP)-4 (endoplasmic reticulum [ER] chaperone), HSP-6 (mitochondrial chaperone), and HSP-16 (cytosolic chaperone), were induced and their expression was regulated at the transcriptional level. These findings suggest that high-dose caffeine intake causes a strong stress response and activates all three stress-response pathways in the worms, including the ER-, mitochondrial-, and cytosolic pathways. RNA interference of each hsp gene or in triple combination retarded growth. In addition, caffeine treatment stimulated a food-avoidance behavior (aversion phenotype), which was enhanced by RNAi depletion of the hsp-4 gene. Therefore, up-regulation of hsp genes after caffeine treatment appeared to be the major responses to alleviate stress and protect against developmental arrest.