• Toxicological Research
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• v.15 no.1
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• pp.89-93
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• 1999

2,3,7,8-Tetrachlorodibenzo-p-dioxin(TCDD) is known to induce cytochrome p450 1A1 and to activate c-Src kinase and p21 Ras. This study examined the molecular interactions of adaptor proteins including Shc, Grb2, and Sos in rat primary hepatocytes and their relationship to the induction of CYP1A1 by TCDD. TCDD induced CYP1A1 level and EROD activity in a dose-dependent mode. Sos/Grb2 association isincreased by TCDDㅑㅜ a dose dependent mode. Tyrosine phosphorylated Shc, mainly p152, onloads to Grb2/Sos complex upon TCDD stimulation. The electrophoretic mobility shift of Sos is showed by TCDD. These results indicate that TCDD modulated the molecular interaction features of adaptor compoes proteins including Shc, Grb2, and Cnl in early signaling pathway of TCDD-mediated CYP 1A1 induction of rat primary hepatocyte.

• Journal of Food Hygiene and Safety
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• v.16 no.2
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• pp.133-138
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• 2001

Toxicological safety on 20 kGy-gamma irradiated Kanjang (soy sauce), Doenjang (soybean paste), Kochujang (hot pepper paste) and Chunghukjang (soy paste) was determined by SOS Chromotest. As the strain of the SOS Chromotest, Escherichia coli PQ37 was used in the condition of presence or absence of an exogenous metabolizing system (S-9 mix). Water extract or organic solvent extract was prepared from samples, concentrated and tested by SOS Chromotest with S-9 mix or not. All irradiated samples were not different from non-irradiated one in the bacterial assay maintaining the below 1.5 of IF(induction factor) values in the adapted dose of 10,000$\mu\textrm{g}$/assay. The results indicated that any mutagenicity was not observed in 20 kGy-irradiated traditional soybean fermented foods.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.174-174
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• 1993

목적: Cinnamic acid의 유도체들중에서 항돌연변이 효과가 보고된 바 있어, 본 연구에서는 E. coil PQ37균주를 사용한 SOS chromotest를 이용하여 약 170개 cinnamic acid의 유도체들의 항돌연변이 효과를 확인하고자 하였고, 1차로 확인된 수종의 유도체들에 대한 결과를 보고하고자 한다. 방법: SOS chromotest는 sul A:: lacz fusion strain 인 E. coli PQ37 에서의 chemical로 인한 DNA damage에 대한 SOS response를 $\beta$-galactosidase enzyme activity level로서 측정하는 실험이며, m-RNA 또는 protein synthesis에 대한 test chemicals의 cytotoxic저해효과를 알아보기 위하여 alkaline phosphatase를 병행측정하여 보완하였다. 결과 및 고찰: (－)S－9 경우는 4-nitroquinoline 1-oxide(4-NQO)를 유도물질로 하였으며 대략 Induction factor가 9.7 정도였고, (＋)S－9의 경우는 aflatoxinB$_1$을 유도물질로 하였고 이때의 Induction factor는 13.8 정도였다. 이결과 1차로 test된 cinnamic acid유도체 6개중에서 RK001, RK002, RK003, RK004, RK005는 거의 항돌연변이 효과를 나타내지 않았으나, RK006은 항돌연변이 효과를 보여주어 이들의 Structure-Activity Relationship (SAR) 및 Dose-response와 RK006의 항돌연변이 효과의 mechanism에 관해 M13 mp2 viral DNA의 유전자 염기서열을 이용하여 항돌연변이 기전연구를 수행중이다.

• Journal of Radiation Industry
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• v.7 no.2_3
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• pp.109-113
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• 2013

In a previous study, a relatively high dose of gamma radiation (1 kGy) did not fully induce typical SOS genes such as sulA, recA, recN, and din in Salmonella Typhimurium (S. Typhimurium) (Lim et al. 2008, Gene expression profiles following high-dose exposure to gamma radiation in Salmonella enterica serovar Typhimuium. J. Radiat. Ind. 3:111-119). In this study, we examined changes in the transcriptional repertoire of S. Typhimurium after a dose of 10 Gy using DNA microarrays. It was found that more than half (~65%) of the 26 up-regulated genes belong to the SOS regulon: ten genes are typical SOS genes, and seven genes are Salmonella prophage genes, which are known to be activated by LexA cleavage. Among 29 down-regulated genes, the function of five genes with the most decreased expression is associated with carbohydrate transport and energy production. This suggests that upon exposure to gamma radiation cells may cease growing by reducing the metabolic activity, and repair DNA damage using a DNA repair system such as the SOS response system. The difference in expression of the SOS genes between a high (1 kGy) and low (10 Gy) dose of radiation shows the possibility that cells may opt for one of multiple regulatory circuits in response to the specific gamma radiation dose.

• YAKHAK HOEJI
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• v.43 no.6
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• pp.771-775
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• 1999

The antimutagenic activities of the total extract and several fractions of starfish, Asterina pectinifera (Asteriidae), were investigated in vitro by SOS chromotest with Escherichia coli PQ37 and Ames test with Salmonella typhimurium TA100. When various fractions was tested, the chloroform and butanol fractions showed low induction factors, which means both fractions increased antigenotoxicity against the base substitution mutagen MNNG. Even though higher antigenotoxic effect of the chloroform fraction, no effective result of Ames test was found in revertant formation of S. typhimurium TA100. The most effective antigenotoxic and antimutagenic fraction was a butanol one: i.e., When 0.5 mg/tube of butanol fraction was applied, the induction factor was 0.68. As the concentration of the fraction was increased the formation of revertants of S. typhimurium TA100 by about 81%. There was no cytotoxic effect of butanol fraction against S.typhimurium TA100. This result might be useful for further study to search a possible anticancer agent from the starfish, Asterina pectinifera.

• Korean Journal of Food Science and Technology
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• v.29 no.6
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• pp.1281-1287
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• 1997

This study was conducted to investigate the antimutagenic effects of methyl alcohol extracts from Auricularia auricula and Gyrophora esculenta on the SOS response induced by 4-nitroquinoline-1-oxide (4NQO), N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), mitomycin C (MMC) and 3-amino-1,4- dimethyl-5H-pyrido-[4,3-b]indol (Trp-P-1) in E. coli PQ37/plasmid pKM101. In the mutagenic test on test strain, both methyl alcohol extracts did not show mutagenic activity. In the antimutagenic test, each sample strongly inhibited the mutagenecity induced by 4NQO, MNNG, MMC and Trp-P-1. Methyl alcohol extracts from Auricularia auricula and Gyrophora esculenta showed inhibitory effects of 52% and 59% against 4NQO, 49% and 58% against MNNG, 53% and 64% against MMC, and 61% and 64% against Trp-P-1, respectively. Gyrophora esculenta extracts on the antimutagenicity showed relatively higher inhibitory effects than that of Auricularia auricula.

• Korean Journal of Food Science and Technology
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• v.28 no.6
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• pp.1059-1064
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• 1996

The inhibitory effects of chitosan on mutagenicity induced by 3-amino-1-methyl-5H-pyrido [4,3-b] indole (Trp-P-2), sodium azide (SA), 2-nitrofluorene (2-NF), and 4-nitroquinoline oxide (4-NQO) were investigated using Salmonella typhimurium reversion assay and SOS Chromotest. In Salmonella typhimurium reversion assay. Chitosan showed 24-65% of inhibitory effect against the mutagenicity of an indirect-acting mutagen, Trp-P-2. On the other hand, no inhibitory effect was observed against the mutagenicity of direct-acting mutagens (2-NF, SA). In SOS chromotest. chitosan showed 46-49% effects on SOS function induced by 4-NQO. Chitosan inhibited the mutagenicity induced by Trp-P-2 with 9-39% of inhibition rate. It was also evaluated whether inhibitory effect of chitosan is due to its bio-antimutagenic or desmutagenic action. Chitosan at high concentrations showed a bio-antimutagenicity with dose-dependent manner, but it showed a desmutagenicity at low concentrations against the mutation induced by Trp-P-2.

• BMB Reports
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• v.28 no.5
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• pp.464-470
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• 1995

Quinolone antibiotics are DNA gyrase inhibitors, but their bactericidal action seems to involve more than the inhibition of DNA gyrase activity. Hence, the potentially crucial factors among possible mechanisms of quinolone action; cleavable complex formation, inhibition of DNA synthesis, and induction of SOS response were investigated. These parameters were measured in an Escherichia coli strain exposed to quinolones in the logarithmic growth phase, and correlated with the bactericidal activity of quinolones. Cleavable complex formation proved to be the factor most related to bactericidal action. Inhibition of DNA synthesis was substantially correlated with bactericidal activity, but induction of SOS response was least correlated with bactericidal activity. Therefore, it was concluded that quinolones exert bactericidal action primarily through cleavable complex formation, and subsequent unknown cellular processes together with inhibition of DNA synthesis contribute to the bactericidal activity of quinolones.

• Journal of Microbiology and Biotechnology
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• v.20 no.1
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• pp.30-38
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• 2010

The contribution of a type II restriction-modification system (R-M system) to genome integrity and cell viability was investigated. We established experimental conditions that enabled the achievement of hemimethylated and unmethylated states for the specific bases of the recognition sequences of the host's DNA. To achieve this, we constructed the MboII R-M system containing only one (i.e., M2.MboII) out of two functional MboII methyltransferases found in Moraxella bovis. Using the incomplete R-M system, we were able to perturb the balance between methylation and restriction in an inducible manner. We demonstrate that upon the SOS-induced DNA repair in mitomycin C treated cells, restriction significantly reduces cell viability. Similar results for the well-studied wild-type EcoRI R-M system, expressed constitutively in Escherichia coli, were obtained. Our data provide further insights into the benefits and disadvantages of maintaining of a type II R-M system, highlighting its impact on host cell fitness.

• Korean Journal of Food Science and Technology
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• v.32 no.6
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• pp.1426-1432
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• 2000

The effects of raw anchovy, salted raw anchovy (20% salt+anchovy), 6- and 12-month fermented anchovy (20% salt added) on the N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced mutagenicities were evaluated using Salmonella assay and the SOS chromotest. The methanol extracts from raw, salted and the fermented anchovy (FA) sample increased the revertants of Salmonella typhimurium TA100 at the level of $0.125{\sim}5\;mg/plate$ in Ames test. The salted raw anchovy extract induced the largest number of the revertants. All the FA extracts had comutagenic effect on the MNNG. Twelve-month FA juice exerted the lowest comutagenic activity among the FA samples. The comutagenicity of 12-month FA was due to the synergistic effect of salt and histidine which teem in FA. Thus the Ames test using histidine requiring mutant, S. typhimurium, is not appropriate to determine the mutagenicity of FA which is rich in histidine. In SOS chromotest using E coli, raw, salted and fermented anchovy extracts did not show any mutagenicity in the absence of MNNG. The raw and fermented anchovy samples blocked the SOS response of E. coli PQ37 induced by MNNG, while raw salted anchovy increased the SOS induction factor. Twelve-month FA juice showed higher antimutagenic effects than 6-month FA samples (both solid and liquid). The ripened (12-month) FA along with raw anchovy in the SOS chromotest exhibited antimutagenic activity.