• Journal of Life Science
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• v.15 no.6 s.73
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• pp.928-934
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• 2005

ATF2 is a cellular transcription factor which belongs to the CREB/ATF class and it is leucine zipper protein which generally binds to DNA as dimers. This paper presents the procedure for subcloning the ATF2 gene and the results of experiment used the expressed ATF2. The pET expression vector was used since it produced 6xHis fusion protein for easy purification using affinity column. The Nickel chelating chromatography was used for Purifying the expressed ATE2 from E- codi BL2l. Subsequen시y In vitro binding pull-down assay showed the binding specificity of ATF2 with AP-1 family factors such as BATF, c-Fos, c-Jun and ATF2 itselgf. ATF2 forms homodimer as well as strong heterodimer with BATF. It also forms stable dimer with c-Jun but barely binds with c-Fos.

• Development and Reproduction
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• v.10 no.2
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• pp.105-113
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• 2006

Reactive oxygen species(ROS) generated in cellular metabolism have an effect on cell maturation and development. In human reproductive tract, oxidative injury by ROS may induce female infertility. Also, oxidative injury may be responsible for developmental retardation and arrest of mammalian preimplantation embryos. Activating transcription factor 4(ATF4) is a member of the cyclic-AMP response element-binding(CREB) familiy of basic region- leucine zipper(bZip). ATF4 is known to regulate stress response to protect cell from various stress factors and inducer of apoptisis. The purpose of this study was to investigate whether ATF4 is involved in the defensive mechanism in oxidative stress condition during the development of mouse preimplantation embryos. To verify the expression of ATF4 in oxidative stress condition, 2-cell stage embryos were cultured in HTF media containing 0.1mM, 0.5mM or 1mM hydrogen peroxide($H_2O_2$) for 1hr(2-cell), 8hr(4-cell), 17hr(8-cell), 24hr(morula), 48hr(early blastocyst) or 64hr(late blastocyst). The developmental rate decreased in the 0.1mM $H_2O_2$ treated group compared with control group. In embryos treated with 0.5mM and 1mM $H_2O_2$ showed 2-cell block. As a results of the semi-quantitative RT-PCR analysis of SOD1, ATF4 and Bax gene expression, SOD1, ATF4 and Bax genes were increased in 0.1mM, 0.5mM, 1mM $H_2O_2$ treated groups compared with control group. In 2-cell embryos, expression of SOD1, ATF4 and Bax genes were notably increased in 0.1mM, 0.5mM, 1mM $H_2O_2$ treated groups compared with control group. Immunofluorescence analysis showed that ATF4 protein was localized at the cytoplasm of preimplantation embryos. The increase in ATF4 immunoreactivety was observed in the 0.1mM, 0.5mM, 1mM $H_2O_2$ treated groups compared with control group. It suggests that oxidative stress by $H_2O_2$ induces expression of ATF4 and may be involved in protection mechanism in preimplantation embryos from oxidative injury.

• Biomolecules & Therapeutics
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• v.24 no.2
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• pp.140-146
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• 2016

Naringenin (NAR) as one of the flavonoids observed in grapefruit has been reported to exhibit an anti-cancer activity. Activating transcription factor 3 (ATF3) is associated with apoptosis in human colon cancer cells. This study was performed to investigate the molecular mechanism by which NAR stimulates ATF3 expression and apoptosis in human colon cancer cells. NAR reduced the cell viability and induced an apoptosis in human colon cancer cells. ATF3 overexpression increased NAR-mediated cleaved PARP, while ATF3 knockdown attenuated the cleavage of PARP by NAR. NAR increased ATF3 expression in both protein and mRNA level, and increased the luciferase activity of ATF3 promoter in a dose-dependent manner. The responsible region for ATF3 transcriptional activation by NAR is located between -317 and -148 of ATF3 promoter. p38 inhibition blocked NAR-mediated ATF3 expression, its promoter activation and apoptosis. The results suggest that NAR induces apoptosis through p38-dependent ATF3 activation in human colon cancer cells.

• Journal of Life Science
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• v.22 no.4
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• pp.492-498
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• 2012

To investigate whether phytochemicals affect cancer cell viability, human colorectal HCT116 cells were treated with four different phytochemicals. Among these phytochemicals, curcumin is the strongest inhibitor of cell proliferation. In addition, it decreased cell viability in a dose-dependent manner. To unveil the molecular mechanisms involved in the inhibition of cell proliferation by curcumin, we carried out oligo DNA microarray analysis. We found that 137 genes were up-regulated more than 2-fold, and 141 genes were down-regulated more than 2-fold by 25 ${\mu}M$ curcumin treatment. Among the up-regulated genes, we selected 3 genes (ATF-3, GADD45A, and NR4A1) to confirm microarray data. The results of RT-PCR strongly agreed with those of the microarray data. Among the phytochemicals used in this study, curcumin is the strongest inducer of ATF3 expression, and increased ATF3 expression in a dose-dependent manner. Interestingly, FACS analysis showed that the inhibition of cell growth by curcumin was recovered by ATF3-siRNA transfection. Finally, we detected the changes of gene expression by ectopic expression of ATF3. The results indicated that many up-regulated genes were related to apoptosis. Overall, these results suggest that ATF3 may play an important role in the anti-proliferative activity of curcumin in human colorectal cancer cells.

• Biomolecules & Therapeutics
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• v.25 no.3
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• pp.337-343
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• 2017

Kahweol as a coffee-specific diterpene has been reported to induce apoptosis in human cancer cells. Although some molecular targets for kahweol-mediated apoptosis have been elucidated, the further mechanism for apoptotic effect of kahweol is not known. Activating transcription factor 3 (ATF3) has been reported to be associated with apoptosis in colorectal cancer. The present study was performed to investigate the molecular mechanism by which kahweol stimulates ATF3 expression and apoptosis in human colorectal cancer cells. Kahweol increased apoptosis in human colorectal cancer cells. It also increased ATF3 expression through the transcriptional activity. The responsible cis-element for ATF3 transcriptional activation by kahweol was CREB located between -147 to -85 of ATF3 promoter. ATF3 overexpression increased kahweol-mediated cleaved PARP, while ATF3 knockdown attenuated the cleavage of PARP by kahweol. Inhibition of ERK1/2 and $GSK3{\beta}$ blocked kahweol-mediated ATF3 expression. The results suggest that kahweol induces apoptosis through ATF3-mediated pathway in human colorectal cancer cells.

• Molecules and Cells
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• v.38 no.1
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• pp.58-64
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• 2015

Activating transcription factor-3 (ATF3) acts as a negative regulator of cytokine production during Gram-negative bacterial infection. A recent study reported that ATF3 provides protection from Streptococcus pneumoniae infection by activating cytokines. However, the mechanism by which S. pneumoniae induces ATF3 after infection is still unknown. In this study, we show that ATF3 was upregulated via Toll-like receptor (TLR) pathways in response to S. pneumoniae infection in vitro. Induction was mediated by TLR4 and TLR2, which are in the TLR family. The expression of ATF3 was induced by pneumolysin (PLY), a potent pneumococcal virulence factor, via the TLR4 pathway. Furthermore, ATF3 induction is mediated by p38 mitogen-activated protein kinase (MAPK) and c-Jun N-terminal kinase (JNK). Thus, this study reveals a potential role of PLY in modulating ATF3 expression, which is required for the regulation of immune responses against pneumococcal infection in macrophages.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.4
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• pp.25-32
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• 2012

Cold start driving cycles exhibit an increases in friction losses due to the low temperatures of metal components and media compared to the normal operating engine conditions. These friction losses are adversely affected to fuel economy. Therefore, in recent years, various techniques for the improvement of fuel economy at cold start driving cycles have been introduced. The main techniques are the upward control of coolant temperature and the fast warm-up techniques. In particular, the fast warm-up techniques are implemented with the coolant flow-controlled water pump and the WHRS (waste heat recovery system). This paper deals with an effect of fast ATF (automatic transmission fluid) warm-up on fuel economy using a recovery system of EGR gas waste heat in a diesel engine. On a conventional diesel engine, two ATF coolers have been connected in series, i.e., an air-cooled ATF cooler is placed in front of the condenser of air conditioning system and a water-cooled one is embedded into the radiator header. However, the new system consists of only a water-cooled heat exchanger that has been changed into the integrated structure with an EGR cooler to have the engine coolant directly from the EGR cooler. The ATF cooler becomes the ATF warmer and cooler, i.e., it plays a role of an ATF warmer if the temperature of ATF is lower than that of coolant, and plays a role of an ATF cooler otherwise. Chassis dynamometer experiments demonstrated the fuel economy improvement of over 2.5% with rapid increase in the ATF temperature.

• Biomolecules & Therapeutics
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• v.23 no.2
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• pp.134-140
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• 2015

Conjugated linoleic acids (CLA) are a family of isomers of linoleic acid. CLA increases growth arrest and apoptosis of human colorectal cancer cells through an isomer-specific manner. ATF3 belongs to the ATF/CREB family of transcription factors and is associated with apoptosis in colorectal cancer. The present study was performed to investigate the molecular mechanism by which t10, c12-CLA stimulates ATF3 expression and apoptosis in human colorectal cancer cells. t10, c12-CLA increased an apoptosis in human colorectal cancer cells in dose dependent manner. t10, c12-CLA induced ATF3 mRNA and luciferase activity of ATF3 promoter in a dose-dependent manner. The responsible region for ATF3 transcriptional activation by t10, c12-CLA is located between -147 and -1850 of ATF3 promoter. mRNA stability of ATF3 was not affected by t10, c12-CLA treatment. t10, c12-CLA increases $GSK3{\beta}$ expression and suppresses IGF-1-stimulated phosphorylation of Akt. The knockdown of ATF3 suppressed expression of $GSK3{\beta}$ and NAG-1 and PARP cleavage. The results suggest that t10, c12-CLA induces apoptosis through ATF3-mediated pathway in human colorectal cancer cells.

• Korean Journal of Plant Resources
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• v.30 no.5
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• pp.556-564
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• 2017

Appropriate soil temperature and early planting of potato is very important for the successful potato-soybean cropping system in central region of South Korea. This experiment was carried out to determine the effect of mulching materials on the growth and yield of potato (Solanum tuberosum L.). Five different mulch treatments were had been applied on an upland soil as follows ; no mulch (NM), transparent film (TF), transparent film + additional transparent film (TF + ATF), black film (BF), and black film + additional transparent film (ATF). In the period of sowing time to removing additional films, mean soil temperature of the treatments was in the order of TF+ATF > TF > BR+ATF > BF as $20.3^{\circ}C$ > $18.5^{\circ}C$ > $16.1^{\circ}C$ > $15.4^{\circ}C$, respectively and that of NM was $13.8^{\circ}C$. The accumulated soil temperature was TF > NM > BF during the removing additional films to earthing at inter-tillage. On the changes in the soil temperature during a whole day, the temperature in the BF was lower than NM during around 18:00 PM to 12:00 NM, while NM was higher than BF in the time period of 10:00AM to 21:00PM. The sequence of potato sprout emergence was 15 > 18 > 20 > 22 days of TF+ATF, TF, BF+ATF, and BF, respectively and that of NM was 24 days. Comparing to the NM, potato sprout emergence was observed on the TF+ATF treated plot as early as 9 days. At 10 days before harvest, the significant difference in the tuber dry weight had been observed and the sequence tuber weight was in the order of TF > TF+ATF > BF+ATF > BF > NM. The potato yields of TF, TF+ATF, and BF+ATF were increased of 40.7, 37.3, and 22% as compared to NM ($2,805kg\;10a^{-1}$), but almost same yield in the BF. The differences of tuber dry weight and potato yields was co-related with the temperature rise of soil by the application of mulching materials on soil. Based on these results, application of mulching film had been very effective to increase the tuber size and the yield of potato by the temperature rise during seedling stage of potato. Transparent mulching was better than black mulching especially for the emergence of sprout of potato in relation to minimizing cooling injury.

• Nuclear Engineering and Technology
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• v.54 no.7
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• pp.2475-2490
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• 2022

The Accident Tolerant Fuel (ATF) is a new concept of fuel, which can not only withstand the consequences of the accident for a longer time, but also maintain or improve the performance under operating conditions. ISAA is a self-developed severe accident analysis code, which uses modular structures to simulate the development processes of severe accidents in nuclear plants. The basic version of ISAA is developed based on UO₂-Zr fuel. To study the potential safety gain of ATF cladding, an improved version of ISAA, referred to as ISAA-ATF, is introduced to analyze the station blackout accident of PWR using ATF cladding. The results show that ATF cladding enable the core to maintain a longer time compared to zirconium alloy cladding, thereby enhancing the accident mitigation capability. Meanwhile, the generation of hydrogen is significantly reduced and delayed, which proves that ATF can improve the safety characteristics of the nuclear reactor.