• Journal of Microbiology and Biotechnology
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• v.22 no.1
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• pp.118-125
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• 2012

Heat shock proteins (Hsps) play a key role in the cellular defense response to diverse environmental stresses. Here, the role of Hsp genes in the acquisition of thermotolerance in the cyanobacterium Microcystis aeruginosa NIES-298 was investigated. Twelve Hsp-related genes were examined to observe their modulated expression patterns at different temperatures (10, 15, 25, and $35^{\circ}C$) over different exposure periods. HspA and HtpG transcripts showed an up-regulation of expression at low temperatures (10 and $15^{\circ}C$) and high temperature ($35^{\circ}C$), compared with the control ($25^{\circ}C$). To examine their effects upon thermotolerance, we purified recombinant HspA and HtpG proteins. During a thermotolerance study at $54^{\circ}C$, the HspA-transformed bacteria showed increased thermotolerance compared with the control. HtpG also played a role in the defense response to acute heat stress within 30 min. These findings provide a better understanding of cellular protection mechanisms against heat stress in cyanobacteria.

• Korean Journal of Plant Tissue Culture
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• v.27 no.1
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• pp.13-18
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• 2000

To investigate the function of chloroplast small HSP, transgenic tobacco plants (Nicotiana tabacum L. cv. Samsun) that constitutively overexpress the chloroplast small HSP (NtHSP21) from N. tabacum cv. Petit Havana SR1 were generated. Five homozygous lines of transformants showing different constitutive expression levels of the NtHSP21 were selected. To determine whether constitutive overexpression of NtHSP21 protein affects thermotolerance, wild-type and transformants were grown in Petri dishes, heat-stressed at 52$^{\circ}C$ for 45 min, and then incubated in normal growth condition. When heat-stressed wild-type plantlets were incubated at $25^{\circ}C$, leaf color gradually became white and all trio plantlets finally died within a week. As for the transformants, however, more than 70% of them remained green and survived under the conditions in which all the wild-type plants were dying. It was also found that the levels of NtHSP21 were correlated with the degree of thermotolerance. These results suggest that the NtHSP21 protein in transformants is responsible for the increase in thermotolerance.

• Korean Journal of Poultry Science
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• v.43 no.2
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• pp.77-88
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• 2016

To establish a new synthetic Korean meat chicken breed, we tested $5{\times}5$ diallel cross mating experiment with domestic chicken breeds. Comparing stress responses among diallel crossed chicken breeds, we analyzed telomere length, DNA damage and expressions of heat shock protein genes (HSPs) as the markers of the stress response. The telomere length was measured by quantitative fluorescence in situ hybridization on the nuclei of lymphocytes. The expression levels of HSP-70, $HSP-90{\alpha}$ and $HSP-90{\beta}$ genes were analyzed by quantitative real-time polymerase chain reaction in lymphocytes. The DNA damage rate of lymphocytes was quantified by the comet assay known as the single cell gel electrophoresis. In results, there were significant differences in the values of the stress markers such as telomere length, HSPs and DNA damage rate, and also were significant differences in viabilities and body weights among the $5{\times}5$ diallel crossed chicken breeds. The telomere shortening rate, expression values of HSPs and DNA damage rate were significant low in W and Y crossed chickens compare to the others, but GG pure breed showed the highest values in the 25 crossed chickens. Estimating correlation coefficient, the survival rate positively correlated to telomere length, but negatively correlated to the expression levels of HSP-70, $HSP-90{\alpha}$, $HSP-90{\beta}$ genes and to the value of % DNA in tail as DNA damage rate. The expression levels of HSP-70, $HSP-90{\alpha}$ and $HSP-90{\beta}$ genes of dead chickens had significantly higher than those of survival chickens. According to the results on the stress marker analysis, it would be considered that the crossed breeds had more stress resistant than the pure breeds, and the crossed chickens with a light strain such as W or Y were relatively resistant to stress, but the crossed chickens with a heavy strain such as G, H, F were susceptible to stress.

• Journal of Information Technology Applications and Management
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• v.25 no.1
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• pp.1-17
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• 2018

This study presents a research model that demonstrates the dominant design technology strategy for developing and securing dominant design technology based on open innovation. For this purpose, this study developed a strategic model for the development and acquisition of design technology, production technology, and production system of propeller which satisfies the requirements of ship propulsion system required by ship owners and shipbuilders. By studying large propellers for ships, it is possible to embody a strategic model that can be used as a technology development strategy of dominant design that is effective in technology field of other industries. In this study, HSP (High Skewed Propeller) strategy of Hyundai Heavy Industries, which occupies the largest global market share (47.5%, 2007) for more than 30 years until now, is analyzed as a successful case to verify this strategic model. The development and acquisition strategy model of dominant design technology presented in this study consists of four stages : dominant design project strategy, dominant design engineering technology strategy, dominant design production technology strategy, and dominant design production system strategy. The strategic model summarizes the key activities at each stage. In addition, the steps and core activities of this strategic model were confirmed through the case study. As a technology development strategy of HSP products, Hyundai Heavy Industries utilized open innovation technology to cooperate with outside, that is, collaborative research and development with KAIST (Korea Advanced Institute of Science and Technology) research team, and succeeded in achieving technology development of dominant design of HSP products by linking it with HSP technology development and acquisition strategy.

• Journal of Aquaculture
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• v.19 no.2
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• pp.77-83
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• 2006

This study was conducted to investigate changes of hemolymph count, antioxidant enzyme activities (catalase: CAT and superoxide dismutase: SOD) and Heat Shock Protein 70 (HSP70) mRNA in hemolymph, hepatopancreas and gill of abalone (Haliotis sieboldii) exposed to various water temperatures. Abalones were exposed to 10, 15, 20, 25 or $30^{\circ}C$ for 0, 6, 12, 24 or 48 hours. Survival rate of abalone was 100% at 10, 15, 20 and $25^{\circ}C$, but 0% at $30^{\circ}C$. Hemolymph counts increased at lower water temperatures (10 and $15^{\circ}C$) and decreased at $30^{\circ}C$. SOD activity decreased immediately after exposure to lower or higher water temperatures compared to the control ($20^{\circ}C$) with an exception at $30^{\circ}C$ where the activity increased. At lower temperatures, SOD activity rose high after 24 hours, but decreased again at 48 hours. At $25^{\circ}C$, it decreased compared to the control. CAT activity decreased immediately after exposure to 10 or $25^{\circ}C$ compared to the control, and then was recovered to the initial level after increment. At $15^{\circ}C$, CAT activity was high after 6 hours, and then was recovered to the initial level after increment. At $30^{\circ}C$, the activity decreased throughout the experiment. The HSP70 mRNA expression in gill increased at lower temperatures compared to the control ($20^{\circ}C$) and $25^{\circ}C$. In this study, rapid change of wale, temperature caused stress response in abalone which had been raised at $20^{\circ}C$. At molecular level, HSP70 was expressed rapidly, but antioxidant enzymes like SOD and CAT were expressed later than HSP70. At 15 and $25^{\circ}C$ of water temperatures, the HSP70, SOD and CAT expression were stable with time. However, at $30^{\circ}C$, all abalone died possibly because they could not develop resistance to high temperature.

• Journal of Aquaculture
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• v.18 no.1
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• pp.7-12
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• 2005

This study was conducted to investigate antioxidant enzyme activity (catalase and superoxide dismutase) and Heat Shock Protein 70 (HSP70) mRNA variation in hepatopancreas of abalone (Haliotis discus hannai) cultured under several acute water temperatures. Abalones were cultured at 10, 15, 20, 25 and $30^{\circ}C$, for 0, 6, 12, 24 and 48 hours, respectively. The HSP70 mRNA expression in hepatopancreas was more increased at $30^{\circ}C$ compared to those at 10. 15, 20 (control) and $25^{\circ}C$. The superoxide dismutase (SOD) activity was increased in hepato-pancreas at all water temperature conditions compared to the control ($20^{\circ}C$). The SOD activity at high water temperature (25 and $30^{\circ}C$) tended to be increased after 12 hours, and was increased immediately after exposure to low water temperature (10 and $15^{\circ}C$). and then was recovered to starting level after the increase. Also, catalase (CAT) activity in hepatopancreas was increased in all the groups except for at $10^{\circ}C$ than the control ($20^{\circ}C$). Survival rate of abalone was $100\%$ at 10, 15, 20 and $25^{\circ}C$, but $92\%$ at $30^{\circ}C$. Thus, according to our study, when abalone is appeared at $20^{\circ}C$, defense mechanism against stress at low water temperature can be accelerated to be stabilized at about $5^{\circ}C$. In the case of exposure of abalone to high water temperature, antioxidant enzyme and HSP70 expression were increased due to elevated physiological stimulation factor, such as temperature.

• Animal cells and systems
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• v.14 no.1
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• pp.17-23
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• 2010

We isolated warm temperature acclimation-related protein 65-kDa (Wap65) cDNA from the liver of olive flounder and investigated the mRNA expression of Wap65 and HSP70 in olive flounder exposed to osmotic (17.5, 8.75, and 4 psu) and thermal stress (25 and $30^{\circ}C$). The mRNA expression of Wap65 and HSP70 was increased by thermal stress. The mRNA expression of HSP70 was also increased by osmotic stress, whereas no significant change in Wap65 expression was detected. These results indicate that Wap65 mRNA expression occurs specifically in response to increases in water temperature, but not in response to osmotic stress. Plasma cortisol levels were also increased by osmotic and thermal stress. We also utilized the stress hormone cortisol to examine whether Wap65 expression is thermal-stress-specific. Cortisol treatment increased HSP70 mRNA expression in vitro, but had no significant effect on Wap65 mRNA expression. Thus, thermal stress, but not osmotic stress, induces Wap65 expression.

• International Journal of Industrial Entomology and Biomaterials
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• v.25 no.1
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• pp.99-110
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• 2012

Comparison on the genomic structure and phylogenetic relationship of the Hsp88 genes from P. tenuipes Jochoen-1, P. tenuipes, C. militaris and C. pruinosa was described. The Hsp88 genes from the three entomopathogenic strains, P. tenuipes Jocheon-1(strain), P. tenuipes(original species), and C. militaris contain the identical genomic structure, namely 5 introns and 6 exons with the length of 13, 62, 32, 1,438, 306, 288 nucleotides encoding 713 amino acid residues, whereas in case of C. pruinosa, it contains 4 introns and 5 exons with the length of 13, 62, 32, 1,744, 288 nucleotides encoding 713 amino acid residues. The genomic DNA length of the Hsp88 genes from P. tenuipes Jocheon-1 and P. tenuipes are both 2,600 nucleotides long in size. The Hsp88 genes from C. militaris and C. pruinosa are 2,582, 2,576 nucleotides long in size, respectively. Hsp88 genes of the P. tenuipes Jochoen-1, P. tenuipes, C. militaris and C. pruinosa also contain the conserved ATP-binding domain. Phylogenetic analysis of the Hsp genes of the four strains tested in this study showed that the fungal Hsp88 is divided into two separate clades, ascomycetes and deutromycete. Within the ascomycetes fungal clade, the P. tenuipes Jochoen-1 and P. tenuipes formed a subgroup, on the other hand, C. militaris and C. pruinosa formed another subgroup. Pair-wise comparison of P. tenuipes Jocheon-1 Hsp88 with those of P. tenuipes, C. militaris and C. pruinosa Hsp88s revealed significant identity in deduced amino acid sequence among these strains. The P. tenuipes Jocheon-1 Hsp88 showed 99% identity with the P. tenuipes, 97% identity with the C. militaris, and 98% identity with the C. pruinosa.

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.2
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• pp.209-219
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• 1997

Previous studies have demonstrated that oxidative stress involving generation of reactive oxygen species (ROS) is responsible for the cytotoxic action of $TNF{\alpha}$. Protective effect of small heat shock proteins (small HSP) against diverse oxidative stress conditions has been suggeted. Although overexpression of small hsp was shown to provide an enhanced survival of $TNF{\alpha}$-sensitive cells when challenged with $TNF{\alpha}$, neither the nature of $TNF{\alpha}$-induced cytotoxicity nor the protective mechanism of small HSP has not been completely understood. In this study, we have attempted to determine whether $TNF{\alpha}$ induces oxidative DNA damage in $TNF{\alpha}$-sensitive L929 cells. We chose to measure the level of 8-hydroxy-2'-deoxyguanosine (8 ohdG), which has been increasingly recognized as one of the most sensitive markers of oxidative DNA damage. Our results clearly demonstrated that the level of 8 ohdG increased in L929 cells in a $TNF{\alpha}$ dose-dependent manner. Subsequently, we asked whether small HSP has a protective effect on $TNF{\alpha}$-induced oxidative DNA damage. To accomplish this goal, we have stably transfected L929 cells with mouse small hsp cDNA (hsp25) since these cells are devoid of endogenous small hsps. We found that $TNF{\alpha}$-induced 8 ohdG was decreased in cells overexpressing exogenous small hsp. We also found that the cell killing activity of $TNF{\alpha}$ was decreased in these cells as measured by clonogenic survival. Taken together, results from the current study show that cytotoxic mechanism of $TNF{\alpha}$ involves oxidative damage of DNA and that overexpression of the small hsp reduces this oxidative damage. We suggest that the reduction of oxidative DNA damage is one of the most important protective mechanisms of small HSP against $TNF{\alpha}$.

• Current Research on Agriculture and Life Sciences
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• v.17
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• pp.15-20
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• 1999

To investigate the function of the chloroplast small heat shock protein (small HSP), transgenic tobacco plants (Nicotiana tabacum L., cv. SRI) that show constitutive expression of the chloroplast small HSP were generated. Effects of constitutive expression of the introduced gene on thermotolerance were first probed with the chlorophyll fluorescence. After a 5-min incubation of leaf discs at high temperatures, an increase in the Fo level and a decrease in the Fv level, indications of separation of LHCII from PSII and inactivation of electron transport reactions in PSII, were mitigated by constitutive expression of the small HSP. When tobacco plantlets grown in Petri dishes were incubated at $52^{\circ}C$ for 45 min and subsequently incubated at $25^{\circ}C$, leaf color of nontransformants was gradually became white and all plantlets finally were died. Under conditions in which all nontransformants were dying, more than 80% of the transformants remained green and survived. These results suggest that the chloroplast small HSP plays an important role in protecting photosynthetic machinery during heat stress.