• Analytical Science and Technology
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• v.17 no.1
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• pp.53-59
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• 2004

Up to now, methods for the detection of genetic alterations as single strand conformation polymorphism (SSCP) or denaturing gradient gel electrophoresis (DGGE) have been used. It is too labor-intensive and expensive to serve for routine analysis. Moreover, lower in its sensitivity and specificity being also strongly dependent on the experience of the investigater. To improve these problems, we analysed mutation of ${\beta}_2$-adrenergic receptor gene that controls bronchial asthma by denaturing high performance liquid chromatography (DHPLC) according to ion-pair reversed phase chromatography (IP-RPC). We extracted genomic DNA from 80 asthma patients and then amplified DNA using PCR and analysed PCR product by SSCP and DHPLC. As a result, we analysed mutation frequency is 19 (23.75%) on SSCP and 25 (31.25%) on DHPLC in ${\beta}_2$-adrenergic receptor gene. We conclude that DHPLC is a fast and simple screening method rather than SSCP analysis.

• Journal of Life Science
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• v.17 no.1 s.81
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• pp.64-69
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• 2007

In the present study, we have investigated the effect of fisetin on the apoptosis and DNA single strand breaks in ultraviolet light B (UVB)-exposed NIH3T3 cells. Exposure of cells to UVB light $(200J/m^2)$ and post-incubation in growth medium for 48 hr resulted in about 50% of cells with apoptotic nuclear fragmentation. Addition of various concentrations of fisetin in the postincubation medium, however, significantly reduced the apoptotic nuclear fragmentation as compared with the values expected when the effects are additive and independent. DNA single strand breaks induced by UVB exposure were also significantly decreased by postincubation with fisetin. By Western blot analysis, fisetin post-incubation was shown to attenuate the p53 upregulation upon UVB exposure. Furthermore, the decrease of proliferating cell nuclear antigen (PCNA) level upon UVB exposure was alleviated by fisetin postincubation. These results suggest that fisetin decrease the apoptosis and increae DNA repair in a possible association with alteration of p53 and PCNA levels in UVB-exposed cells.

• Molecules and Cells
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• v.39 no.7
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• pp.550-556
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• 2016

During meiosis, exchange of DNA segments occurs between paired homologous chromosomes in order to produce recombinant chromosomes, helping to increase genetic diversity within a species. This genetic exchange process is tightly controlled by the eukaryotic RecA homologs Rad51 and Dmc1, which are involved in strand exchange of meiotic recombination, with Rad51 participating specifically in mitotic recombination. Meiotic recombination requires an interaction between homologous chromosomes to repair programmed double-strand breaks (DSBs). In this study, we investigated the budding yeast meiosis-specific proteins Hop2 and Sae3, which function in the Dmc1-dependent pathway. This pathway mediates the homology searching and strand invasion processes. Mek1 kinase participates in switching meiotic recombination from sister bias to homolog bias after DSB formation. In the absence of Hop2 and Sae3, DSBs were produced normally, but showed defects in the DSB-to-single-end invasion transition mediated by Dmc1 and auxiliary factors, and mutant strains failed to complete proper chromosome segregation. However, in the absence of Mek1 kinase activity, Rad51-dependent recombination progressed via sister bias in the $hop2{\Delta}$ or $sae3{\Delta}$ mutants, even in the presence of Dmc1. Thus, Hop2 and Sae3 actively modulate Dmc1-dependent recombination, effectively progressing homolog bias, a process requiring Mek1 kinase activation.

• The Korean Journal of Food And Nutrition
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• v.30 no.4
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• pp.673-680
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• 2017

Fludarabine, a chain terminating anti-cancer drug, is a purine analogue that causes DNA strand breaks in normal cells. In this study, we determined if A. melanocarpa and Korean red ginseng extract mixture reduce cytotoxicity of fludarabine. Treatment of HaCaT cells with $10{\mu}M$ of fludarabine for 24 hours decreased cell viability and increased DNA strand breaks. Treatment of A. melanocarpa and Korean red ginseng extract mixture for 24 hours increased cell viability as compared with single extract treatment. The protective effect of these extracts on cell activity increased in a concentration-dependent manner. DNA strand breaks induced by fludarabine decreased as concentration of extract mixture increased. p-H2AX level, a marker of DNA strand breakage, decreased depending on the concentration of extract mixture. The effect of mixed extract of A. melanocarpa and Korean red ginseng on DNA damage is due to the anti-oxidative effect of A. melanocarpa and signal transmission through glucocorticoid receptor upon binding of saponin of Korean red ginseng.

• Journal of Microbiology and Biotechnology
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• v.30 no.3
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• pp.469-475
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• 2020

During meiosis I, programmed DNA double-strand breaks (DSBs) occur to promote chromosome pairing and recombination between homologs. In Saccharomyces cerevisiae, Mec1 and Tel1, the orthologs of human ATR and ATM, respectively, regulate events upstream of the cell cycle checkpoint to initiate DNA repair. Tel1^ATM and Mec1^ATR are required for phosphorylating various meiotic proteins during recombination. This study aimed to investigate the role of Tel1^ATM and Mec1^ATR in meiotic prophase via physical analysis of recombination. Tel1^ATM cooperated with Mec1^ATR to mediate DSB-to-single end invasion transition, but negatively regulated DSB formation. Furthermore, Mec1^ATR was required for the formation of interhomolog joint molecules from early prophase, thus establishing a recombination partner choice. Moreover, Mec1^ATR specifically promoted crossover-fated DSB repair. Together, these results suggest that Tel1^ATM and Mec1^ATR function redundantly or independently in all post-DSB stages.

• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1869-1871
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• 2001

DNA 센서의 중요한 역할 중의 하나는 염기서열을 분석함으로써 유전적인 질병이나 돌연변이를 찾아낸다는 점이다. 염기서열 분석법으로 질량, 광학, 전기 화학적 측정법 등이 있는데, 그 중 전기 화학적 측정방법이 타 방법에 비해 간편하고 비용도 저렴해서 전망이 매우 밝다. 전기 화학적 측정을 위해서는 전극의 표면 처리 공정과 전극 표면에서의 DNA immobilization, hybridization 공정 및 전기적 신호를 발생시키는 intercalator, 그리고 전기적 신호 검출을 위한 측정 장비가 필요하다. 본 논문에서는 전극의 표면 처리 물질로서 2-mercaptoethanol을 사용했고 double strand DNA의 intercalator로써 methylene blue를 사용했으며, methylene blue의 환원 전류값을 측정하여 double strand DNA를 bare Au 또는 single strand DNA와 구분할 수 있었다. 이러한 연구 결과를 토대로 하여 전기 화학적 신호 검출을 이용한 DNA 센서의 가능성과 개발 방향을 제시하고자 한다.

• Journal of Photoscience
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• v.9 no.3
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• pp.49-50
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• 2002

N-Nitrosoproline(NPRO) is endogenously formed from proline and nitrite. NPRO has been reported to be nonmutagenic and noncarcinogenic. In this study, we have detected the direct mutagenicity of NPRO with UVA and UVB towards S. typhimurium. Formation of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), a mutagenic lesion, was observed in calf thymus DNA treated with NPRO plus simulated sunlight. Furthermore, the treatment with NPRO and sunlight induced single strand breaks in the superhelical replicative form of phage M13mp2 DNA. An analysis using scavengers suggested that both reactive oxygen species and NO radical mediate the strand breaks. The formation of nitric oxide was observed in NPRO solution irradiated with UVA. The co-mutagenic and co-toxic actions of NPRO and sunlight merit attention as possible mechanisms increasing the carcinogenic risk from UVA irradiation.

• Proceedings of the Korean Vacuum Society Conference
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• 2005.02a
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• pp.132-132
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• 2005

• Proceedings of the Zoological Society Korea Conference
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• 2001.10a
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• pp.225.1-225
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• 2001

No Abstract, See Full Text

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.622-622
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• 2005