• The Korean Journal of Physiology and Pharmacology
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• 제7권3호
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• pp.157-162
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• 2003

Our earlier studies found a significant correlation between the activities of ranitidine N-oxidation catalyzed by hepatic flavin-containing monooxygenase (FMO) and the presence of mutations in exon 4 (E158K) and exon 7 (E308G) of the FMO3 gene in Korean volunteers. However, caffeine N-1 demethylation (which is also partially catalyzed by FMO) was not significantly correlated with these FMO3 mutations. In this study, we examined another common mutation (V257M) in exon 6 of FMO3 gene. The V257M variant, which is caused by a point mutation (G769A), was commonly observed (13.21% allele frequency) in our subjects (n=159). This point mutation causes a substitution of $Val^{257}$ to $Met^{257}$, with transformation of the secondary structure. The presence of this mutant allele correlated significantly with a reduction in caffeine N-1-demethylating activity, but was not correlated with the activity of N-oxidation of ranitidine. In a family study, the low FMO activity observed in a person heterozygous for a nonsense mutation in exon 4 (G148X) and heterozygous for missense mutation in exon 6 (V257M) of FMO3 was attributed to the mutations. Our results suggest that various point mutations in the coding regions of FMO3 may influence FMO3 activity according to the probe substrates of varying chemical structure that correlate with each mutation on the FMO3 gene.

• BMB Reports
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• 제56권5호
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• pp.265-274
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• 2023

Defects in DNA double-strand break (DSB) repair signaling permit cancer cells to accumulate genomic alterations that confer their aggressive phenotype. Nevertheless, tumors depend on residual DNA repair abilities to survive the DNA damage induced by genotoxic stress. This is why only isolated DNA repair signaling is inactivated in cancer cells. DNA DSB repair signaling contributes to general mechanism for various types of lesions in diverse cell cycle phases. DNA DSB repair genes are frequently mutated and amplified in cancer; however, limited data exist regarding the overall genomic prospect and functional result of these modifications. We list the DNA repair genes and related E3 ligases. Mutation and expression frequencies of these genes were analyzed in COSMIC and TCGA. The 11 genes with a high frequency of mutation differed between cancers, and mutations in many DNA DSB repair E3 ligase genes were related to a higher total mutation burden. DNA DSB repair E3 ligase genes are involved in tumor suppressive or oncogenic functions, such as RNF168 and FBXW7, by assisting the functionality of these genomic alterations. DNA damage response-related E3 ligases, such as RNF168, FBXW7, and HERC2, were generated with more than 10% mutation in several cancer cells. This study provides a broad list of candidate genes as potential biomarkers for genomic instability and novel therapeutic targets in cancer. As a DSB related proteins considerably appear the possibilities for targeting DNA repair defective tumors or hyperactive DNA repair tumors. Based on recent research, we describe the relationship between unstable DSB repairs and DSB-related E3 ligases.

• 한국작물학회지
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• 제24권2호
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• pp.27-34
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• 1979

수도의 돌연변이를 보다 효율적으로 선발키 위한 수단을 모색코저 진흥의 성숙종자에 ethyl methanesulfonate(EMS)를 처이하여 $_{x}\textrm{M}_1식물체에 미치는 영향과 $_{x}\textrm{M}_2의 돌연변이율 등을 분얼별로 조사하고 이들 상호간의 관계를 검토해 보았다. EMS를 처리하면 $_{x}\textrm{M}_1식물체의 간장은 길어지는 반면, 분얼은 전반적으로 억제되었는데 주간과 상위 제 7, 8절의 1차분얼만은 오히려 출현율이 증가하는 치향이 있었다. 주간이 $_{x}\textrm{M}_1주내에서 최장간이 되는 율은 EMS의 농도가 높을수록 현저히 증가하였다. 분얼군별 돌연변이율은 1차분얼의 것이 가장 높아 이삭당으로 4.7%이었고, 2차분얼이 3.9%, 주간의 것이 2.5%로 가장 낮다. 또 변이율은 $_{x}\textrm{M}_1이삭의 불염율과도 관계가 있어 불염이 41~60%의 범위일 때 8.2%의 돌연변이율을 나타내어 가장 높고 이보다 높거나 낮은 군에서는 변이율이 낮았다. EMS를 돌연변이유기원으로 사용할 경우 $_{x}\textrm{M}_2 돌연변이율을 높이기 위해서는 주내에서 간장이 제일 큰 주간을 제외하고 나머지 1차 혹은 2차분얼의 이삭을 선발하되 $_{x}\textrm{M}_1이삭의 불염이 40~60%정도의 것을 취하여 다음 $_{x}\textrm{M}_2 세대를 양성하는 것이 $_{x}\textrm{M}_2의 돌연변이를 효율적으로 선발할 수 있는 수단이 될 것 같다.

• Genomics & Informatics
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• 제16권2호
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• pp.22-29
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• 2018

Incorporation of unique barcodes into fission yeast gene deletion collections has enabled the identification of gene functions by growth fitness analysis. For fine tuning, it is important to examine barcode sequences, because mutations arise during strain construction. Out of 8,708 barcodes (4,354 strains) covering 88.5% of all 4,919 open reading frames, 7,734 barcodes (88.8%) were validated as high-fidelity to be inserted at the correct positions by Sanger sequencing. Sequence examination of the 7,734 high-fidelity barcodes revealed that 1,039 barcodes (13.4%) deviated from the original design. In total, 1,284 mutations (mutation rate of 16.6%) exist within the 1,039 mutated barcodes, which is comparable to budding yeast (18%). When the type of mutation was considered, substitutions accounted for 845 mutations (10.9%), deletions accounted for 319 mutations (4.1%), and insertions accounted for 121 mutations (1.6%). Peculiarly, the frequency of substitutions (67.6%) was unexpectedly higher than in budding yeast (~28%) and well above the predicted error of Sanger sequencing (~2%), which might have arisen during the solid-phase oligonucleotide synthesis and PCR amplification of the barcodes during strain construction. When the mutation rate was analyzed by position within 20-mer barcodes using the 1,284 mutations from the 7,734 sequenced barcodes, there was no significant difference between up-tags and down-tags at a given position. The mutation frequency at a given position was similar at most positions, ranging from 0.4% (32/7,734) to 1.1% (82/7,734), except at position 1, which was highest (3.1%), as in budding yeast. Together, well-defined barcode sequences, combined with the next-generation sequencing platform, promise to make the fission yeast gene deletion library a powerful tool for understanding gene function.

• Animal cells and systems
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• 제7권3호
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• pp.265-269
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• 2003

Vascular endothelial growth factor (VEGF) is a potent regulator of normal and abnormal angiogenesis. Recent literature suggests that VEGF has several activities that may amplify acute inflammation reactions. Dysregulated VEGF expression has been implicated as a major contributor to the development of a number of common disease pathologies. One of common mutations in the 3'- untranslated region of the VEGF gene, a C\longrightarrowT exchange at nucleotide position 936, has been found to be significantly associated with VEGF expression levels in the plasma from a previous Austrian study. The frequency of this mutation could be important genetic information regarding tumor growth and angiogenesis related diseases. The aim of this study was to investigate the frequency distribution of this mutation in general Korean population. We examined the statistical data from 207 healthy Korean subjects. Observed numbers (%) of 936T were 28.5 (CT) and 3.9 (TT), respectively. The mutant allele frequency of 936T in Korean subjects was 0.18, which appeared somewhat higher than that in Austrian subjects.

• Journal of Plant Biology
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• 제5권1호
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• pp.1-6
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• 1962

1) Germination rate was rather irregular than decreasing as increasing dose of radiation and there were no differences between Kyong-Sam and Chuong-Bang of Chinese cabbage. 2) In R1 generation, abnormal leaves from seedling of irradiated seeds were observed. These were more apparent in X-ray irradiation than in thermal neutron. 3) Seedling height was inhibited with increasing dose of X-ray and thermal neutrons. Growth inhibition was more remarkable in X-ray than in thermal neutron. Kyong-Sam demonstrated more sensitivity than Chyong-Bang in both X-ray and thermal neutron. 4) Seedling height produced from seeds subjected to thermal neutrons showed small variation around its mean value, while in X-irradiation there was a greater deviaton from the mean value. 5) Fertility was decreased as increasing with dose, while the frequency of abortive pollen was increased. There were variability of the fertility and frequency of abortive pollen among plants or branches of a plant. 6) The mutants were obtained more in thermal neutron irradiation than in X-ray. The types of mutations obtained in Chinese radish of R2 generation were abnormal leaf, densely glowing leaf, degeneration in growing point and dwarf. The maximum frequency of phenotypic mutations was abnormal leaf mutation.

• Journal of Microbiology and Biotechnology
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• 제17권4호
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• pp.701-704
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• 2007

This report describes the full-length sequences of 2HBV clones from a hepatocellular carcinoma (HCC) patient, one with preC mutation (1896A) and the other without preC mutation. The high level of discrepancy in mutation frequency between these 2 strains was observed in the Core (C) region among 4 ORFs. These data support previous results that Korean HBV strains, belonging to genotype C2, are prone to mutations. It is possible that the mutations (BCP and preC mutations) associated with the HBeAg defective production might contribute to the diversity of mutations related to HBV persistence, playing an important role in hepatocarcinogenesis in this patient.

• 대한미생물학회지
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• 제35권2호
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• pp.181-190
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• 2000

To investigate resistance to lamivudine (3TC), we examined the incidence of M184V in 20 HIV-1 patients treated with 3TC for $13.1{\pm}9$ months. Fourteen of 20 patients had been exposed to zidovudine (ZDV) or didanosine (ddI) prior to 3TC therapy. Nested PCR targeting to reverse transcriptase (RT) and direct sequencing were performed for peripheral blood mononuclear cells sampled serially. There were resistance mutations to ZDV in at least 9 patients at baseline, although there was no resistance mutation to 3TC. We could detect M184V in 6 (30%) out of 20 patients. The incidence of M184V increased as the duration of therapy prolongs (13% in samples <12 months; 47% in samples ${\ge}12$ months). The frequency of mutation M184V was higher in patients with previous mutation to ZDV than in patients with wild type. Resistance mutation was not detected in 7 patients. This study shows that resistance to 3TC tends to develop rapidly in patients with baseline mutations or two drugs combination therapy than in those treated simultaneously with triple drugs. This report is the first on resistance to 3TC in Korean AIDS patients.

• 생명과학회지
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• 제20권3호
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• pp.453-456
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• 2010

백혈병은 조혈모세포의 비정상적인 증식에 의해 일어나서 질환이고, adenosine deaminase (ADA) 유전자는 백혈병의 약물 작용점으로 중요하다. 이러한 연구의 일환으로 한국인 백혈병 환자 20명의 ADA 유전자의 변이를 조사하기 위해 혈액 genomice DNA를 추출하여 염기서열을 결정하였다. 그 결과 nonsense 변이인 F101F 하나, missense 변이 E260K, D8Y 각각 하나, 그리고 외국에서는 보고되지 않은 것으로 정상인에서 IVS6-52 에 GC가 도입된 것을 확인하였다. 백혈병 환자와 유전자 변이간에 통계학적인 차이점은 없지만 이러한 연구는 앞으로 백혈병의 진단 마크 개발에 도움이 될 것으로 사료된다.

• Genomics & Informatics
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• 제18권4호
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• pp.44.1-44.7
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• 2020

The severity of coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), greatly varies from patient to patient. In the present study, we explored and compared mutation profiles of SARS-CoV-2 isolated from mildly affected and severely affected COVID-19 patients in order to explore any relationship between mutation profile and disease severity. Genomic sequences of SARS-CoV-2 were downloaded from Global Initiative on Sharing Avian Influenza Data (GISAID) database. With the help of Genome Detective Coronavirus Typing Tool, genomic sequences were aligned with the Wuhan seafood market pneumonia virus reference sequence and all the mutations were identified. Distribution of mutant variants was then compared between mildly and severely affected groups. Among the numerous mutations detected, 14408C>T and 23403A>G mutations resulting in RNA-dependent RNA polymerase (RdRp) P323L and spike protein D614G mutations, respectively, were found predominantly in severely affected group (>82%) compared with mildly affected group (<46%, p < 0.001). The 241C>T mutation in the non-coding region of the genome was also found predominantly in severely affected group (p < 0.001). The 3037C>T, a silent mutation, also appeared in relatively high frequency in severely affected group compared with mildly affected group, but the difference was not statistically significant (p = 0.06). We concluded that spike protein D614G and RdRp P323L mutations in SARS-CoV-2 are associated with severity of COVID-19. Further studies will be required to explore whether these mutations have any impact on the severity of disease.