• Journal of the Korean Magnetic Resonance Society
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• v.18 no.2
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• pp.52-57
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• 2014

The TCP domain is a DNA-binding domain present in plant transcription factors and plays important roles in various biological functions. The hydrogen exchange rate constants of the imino protons were determined for the three DNA duplexes containing the DNA-binding sites for the TCP11, TCP15, and TCP20 transcription factors using NMR spectroscopy. The M11 duplex displays unique hydrogen exchange property of the five base pairs in the first binding site (5'-GTGGG-3'). However, the M15 and M20 duplexes lead to clear changes in thermal stabilities of these five base pairs. The unique dynamic features of the five base pairs in the first binding site might play crucial roles in the sequence-specific DNA binding of the class I TCP transcription factors.

• Current Research on Agriculture and Life Sciences
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• v.31 no.2
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• pp.101-107
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• 2013

This study was undertaken to determine free radical scavenging capacity and oxidative DNA damage protecting activity of methanol extract of red tea stem. The extract was subjected to assess their antioxidant potential using various in vitro systems such as $DPPH^{\bullet}$, $ABTS^{{\bullet}+}$, super oxide and nitric oxide free radicals and it exhibited $IC_{50}$ values of $68.88{\pm}1.1$, $12.08{\pm}0.65$, $404.38{\pm}1.6$, $93.6{\pm}2.7{\mu}g/mL$ respectively. Red tea extract also showed ferric reducing ability (FRAP) with 2606.85 mmol Fe (II)/g of extract. Furthermore, Methanol extract of red tea stem showed significant DNA damage protecting activity in concentration dependent manner against $H_2O_2+UV$ induced photolysis on pUC19 plasmid DNA. Results of this study showed that the methanol extract of Red Tea stem has strong antioxidant potential along oxidative DNA damage protecting capacity that would be the significant sources of natural antioxidants, which might be helpful in preventing the progress of various oxidative stress generated diseases. Further study is necessary for isolation and characterization of the active antioxidants, which may serve as a potential source of natural antioxidant.

• Journal of Microbiology and Biotechnology
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• v.27 no.8
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• pp.1367-1378
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• 2017

Epigenetic alterations such as DNA methylation, histone acetylation, and chromatin remodeling can control gene expression by regulating gene transcription. DNA methylation is one of the frequent epigenetic events that play important roles in cancer development. Cancer cells can gain significant resistance to anticancer drugs and escape programmed cell death through major epigenetic changes, including DNA methylation. To date, several research groups have identified instances of both (i) hypermethylation of tumor suppressor genes, and (ii) global hypomethylation of oncogenes. These changes in DNA methylation status could be used as biomarkers for the diagnosis and prognosis of cancer patients undergoing chemotherapies or other clinical therapies. Herein, we describe genes for which methylation is dependent upon anticancer drug resistance in patients with gastric cancer; we then suggest a significant epigenetic target to focus on for overcoming anticancer drug resistance.

• Bulletin of the Korean Chemical Society
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• v.32 no.7
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• pp.2217-2221
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• 2011

We investigated the selective deoxyribonucleic acid (DNA) adsorption on layered double hydroxide (LDH) nanoparticles via studying the interaction between positively charged LDH nanoparticle as adsorbent and negatively charged adsorbates such as methyl orange (MO), fluorescein (FL), and DNA strands. The size controlled LDH $(Mg_{0.78}Al_{0.22}(OH)_2(CO_3)_{0.11}{\cdot}mH_2O)$ was prepared by conventional coprecipitation method, followed by the hydrothermal treatment. According to the adsorption isotherms, the adsorbed amounts of MO and FL were similar, however, that of DNA were much larger. The adsorption behaviors were well fitted to Freundlich adsorption model. The concentration dependent adsorption behavior on LDH surface was described in order to verify the selective DNA separation ability. The result showed that the LDH has advantages in selective adsorption of DNA competing with single molecular anions.

• Proceedings of the Microbiological Society of Korea Conference
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• 1991.04a
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• pp.82-96
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• 1991

To understand the mechanism of illegitimate recombination in mammalian cells, we have examined the recombination role of DNA topoisomerase II (Topo II ). We found that purified calf thymus Topo II mediates recombination between two phage $\lambda$ DNA molecules in an in vitro system. The enzyme mainly produced a linear monomer recombinant DNA that can be packaged in vitro. Novobiocin and anti-calf thymus Topo II antibody inhibit this ATP-dependent recombination. The recombinant molecules contain duplications or deletion, and most crossovers take place between nonhomologous sequences of $\lambda$ DNA, as judged by the sequences of recombination junctions. In order to study the effects of Topo II on illegitimate recombination in mammalian cells, we have developed a new shuttle vector, pNKl, which contains three bacterial genes, amp(APR), galK and neo($Km^R$). Using this system, we have shown that a Topo II inhibitor, VM26, stimulated deletion formation in pNK1 DNA in monkey COS1 cells. Both in vitro and in vivo results suggest that Topo II participates in illegitimate recombination in mammalian cells.

• BMB Reports
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• v.51 no.3
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• pp.126-133
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• 2018

Hippo signaling plays critical roles in regulation of tissue homeostasis, organ size, and tumorigenesis by inhibiting YES-associated protein (YAP) and PDZ-binding protein TAZ through MST1/2 and LATS1/2 pathway. It is also engaged in cross-talk with various other signaling pathways, including WNT, BMPs, Notch, GPCRs, and Hedgehog to further modulate activities of YAP/TAZ. Because YAP and TAZ are transcriptional coactivators that lack DNA-binding activity, both proteins must interact with DNA-binding transcription factors to regulate target gene's expression. To activate target genes involved in cell proliferation, TEAD family members are major DNA-binding partners of YAP/TAZ. Accordingly, YAP/TAZ were originally classified as oncogenes. However, YAP might also play tumor-suppressing role. For example, YAP can bind to DNA-binding tumor suppressors including RUNXs and p73. Thus, YAP might act either as an oncogene or tumor suppressor depending on its binding partners. Here, we summarize roles of YAP depending on its DNA-binding partners and discuss context-dependent functions of YAP/TAZ.

• Archives of Pharmacal Research
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• v.27 no.7
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• pp.797-805
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• 2004

LPD vectors are non-viral vehicles for gene delivery comprised of polycation-condensed plasmid DNA and liposomes. Here, we described a novel anionic LPD formulation containing protamine-DNA complexes and pH sensitive liposomes composed of DOPE and cholesteryl hemisuccinate (Chems). Central composite design (CCD) was employed to optimize stable LPD formulation with small particle size. A three factor, five-level CCD design was used for the optimization procedure, with the weight ratio of protamine/DNA ($X_1$), the weight ratio of Chems/DNA ($X_2$) and the molar ratio of Chems/DOPE in the anionic liposomes ($X_3$) as the independent variables. LPD size ($Y_1$) and LPD protection efficiency against nuclease ($Y_2$) were response variables. Zeta potential determination was utilized to define the experimental design region. Based on experimental design, responses for the 15 formulations were obtained. Mathematical equations and response surface plots were used to relate the dependent and independent variables. The mathematical model predicted optimized $X_1-X_3$ levels that achieve the desired particle size and the protection efficiency against nuclease. According to these levels, an optimized LPD formulation was prepared, resulting in a particle size of 185.3 nm and protection efficiency of 80.22％.

• Bulletin of the Korean Chemical Society
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• v.15 no.5
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• pp.364-368
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• 1994

Growth inhibition potency of the anthraquinones, anthraquinone-1,5-disulfonic acid and carminic acid, for Sarcoma 180 and L1210 leukemia cells in vivo and in vitro, was induced by the divalent transition metal ion, $Cu^{2+}$. On the other hand spectroscopic titration data show that the anthraquinone drugs form $Cu2^+$ chelate complexes (carminic acid : $Cu^{2+}$ = 1 : 6; anthraquinone-1,5-disulfonic acid : $Cu^{2+}$ = 1 : 3). Furthermore the $Cu^{2+}$-drug complexes associate with DNA to form the $Cu^{2+}$-anthraquinone-DNA ternary complexes. The formation of the complexes was further supported by the $H_2O_2-dependent$ DNA degradation, which can be inhibited by ethidium bromide, caused by the $Cu^{2+}$-drug complexes. It is likely that the $Cu^{2+}$-mediated cytotoxicity of the anthraquinone drugs is related with the $Cu^{2+}-mediated$ binding of the anthraquinone drugs to DNA and DNA degradation.

• Journal of Ecology and Environment
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• v.46 no.2
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• pp.126-135
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• 2022

Background: Pollinators are important ecological elements due to their role in the maintenance of ecosystem health, wild plant reproduction, crop production and food security. The pollinator-plant interaction supports the preservation of plant and animal populations and it also improves the yield in pollination dependent crops. Having knowledge about the plant-pollinator interaction is necessary for development of pesticide risk assessment of pollinators and conservation of endangering species. Results: Traditional methods to discover the relatedness of insects and plants are based on tracing the visiting pollinators by field observations as well as palynology. These methods are time-consuming and needs expert taxonomists to identify different groups of pollinators such as insects or identify flowering plants through palynology. With pace of technology, using molecular methods become popular in identification and classification of organisms. DNA metabarcoding, which is the combination of DNA barcoding and high throughput sequencing, can be applied as an alternative method in identification of mixed origin environmental samples such as pollen loads attached to the body of insects and has been used in DNA-based discovery of plant-pollinator relationship. Conclusions: DNA metabarcoding is practical for plant-pollinator studies, however, lack of reference sequence in online databases, taxonomic resolution, universality of primers are the most crucial limitations. Using multiple molecular markers is preferable due to the limitations of developed universal primers, which improves taxa richness and taxonomic resolution of the studied community.

• Journal of Food Hygiene and Safety
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• v.31 no.1
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• pp.1-7
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• 2016

In the present study, our aim was to determine whether green tea extract (GTE) and its major constituent, epigallocatechin-3-gallate (EGCG) have a protective effect on ethanol-induced cytotoxicity and DNA damage in NIH/3T3 and HepG2 cells. The cell viability and DNA single strand breaks were examined by MTT assay and alkaline single cell gel electrophoresis (Comet assay), respectively. Ethanol decreased the cell viability and also increased DNA single strand breaks in a concentration-dependent manner. On the other hand, GTE showed the protective effect of cytotoxicity and DNA damage induced by ethanol in both cell lines. GTE and EGCG, were found to possess the anti-oxidative and anti-genotoxic activities by evaluation with DPPH test, LDL oxidation assay, oxidative DNA damage assay and 8OH-2'dG generation test. These results were also verified by the experimental results demonstrating the lower cytotoxicity and genotoxicity of commercial green tea liqueur compared to pure ethanol in same concentration. Thus it is concluded that the supplementation of GTE or EGCG may mitigate the ethanol-induced cytotoxicity and DNA damage.