• Archives of Pharmacal Research
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• 제21권3호
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• pp.320-325
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• 1998

To elucidate of role(s) of tTA as a repressor in the tTA-mediated gene repression system, we introduced mutations into the acidic domain of VP16 and examined the effects of such various mutations. In the transient repression experiment, a region containing 34 amino acids of the activation domain of VP16 (412-456) which interacts with TFIIB was found to be necessary and sufficient for the tTA-mediated repression of gene expression. However, in the experiment to investigate the fact that tTA-regulated repression is related to the activation function of VP16, we found that the repression abilities of tTA derivatives did not correlate exactly with their activation abilities. Therefore, we conclude that increased mass of VP16 in tTA might be also important for efficient repression in addition to functional domain of VP16.

• 대한구순구개열학회지
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• 제11권2호
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• pp.65-70
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• 2008

Cleft lip and/or palate are common birth defects in humans and the causes including multiple genetic and environmental factors are complex. Combinations of genetic, biochemical, and embryological approaches in the laboratory mice are used to investigate the molecular mechanisms underlying normal craniofacial development and the congenital craniofacial malformations including cleft lip and/or palate. Both forward and reverse genetic approaches are used. The forward genetic approach involves identification of causative genes and molecular pathways disrupted by uncharacterized mutations that cause craniofacial malformations including cleft lip and/or cleft palate. The reverse genetic approach involves generation and analyses of mice carrying null or conditional mutations using the Cre-loxP mediated gene targeting techniques.

• Asian Pacific Journal of Cancer Prevention
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• 제15권3호
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• pp.1247-1253
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• 2014

Mutations in the DNMT3A and IDH genes represent the most common genetic alteration after FLT3/NPM1 in acute myeloid leukemia (AML). We here analyzed the frequency and distribution pattern of DNMT3A and IDH mutations and their associations with other molecular markers in normal karyotype AML patients. Fortyfive patients were screened for mutations in DNMT3A (R882), IDH1 (R132) and IDH2 (R140 and R172) genes by direct sequencing. Of the 45 patients screened, DNMT3A and IDH mutations were observed in 6 (13.3%) and 7 (15.4%), respectively. Patients with isolated DNMT3A mutations were seen in 4 cases (9%), isolated IDH mutations in 5 (11.1%), while interestingly, two cases showed both DNMT3A and IDH mutations (4.3%). Nucleotide sequencing of DNMT3A revealed missense mutations (R882H and R882C), while that of IDH revealed R172K, R140Q, R132H and R132S. Both DNMT3A and IDH mutations were observed only in adults, with a higher frequency in males. DNMT3A and IDH mutations were significantly associated with NPM1, while trends towards higher coexistence with FLT3 mutations were observed. This is the first study to evaluate DNMT3A/IDH mutations in Indian patients. Significant associations among the various molecular markers was observed, that highlights cooperation between them and possible roles in improved risk stratification.

• 대한유전성대사질환학회지
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• 제14권2호
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• pp.174-177
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• 2014

단독 메틸말론산혈증은 상염색체 열성으로 유전되는 선천성 유전대사질환으로 methylmalonyl-coenzyme A mutase (MCM)의 결핍에 의해 야기된다. MCM를 코딩하는 MUT 유전자의 돌연변이가 단독 메틸말론산 혈증의 주된 원인이다. 저자들은 생후 15일 여아가 신생아 선별검사를 통하여 C3-acylcarnitine (C3)이 증가되어 있었던 증례를 경험하였다. 환아의 혈장 homocysteine은 정상이었고, 소변 methylmalonic acid는 증가되어 있어서 단독 메틸말론산혈증이 의심되었다. 환아는 단백제한식이와 함께 carnitine 보충요법을 시작하였고, 생후 3개월까지 특별한 증상없이 정상적인 성장을 하고 있다. MUT 유전자 검사를 시행하였으며, 환아는 c.323G>A와 c.1672+2T>C (IVS8 (+2)T>C 변이를 각각 이형접합자로 가지고 있었다. 이중 c.1672+2T>C (IVS8(+2)T>C)은 이전에 보고되지 않은 새로운 돌연변이로 이에 증례 보고하는 바이다.

• Journal of Microbiology
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• 제43권5호
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• pp.391-397
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• 2005

Escherichia coli is a common inhabitant of the intestinal tracts of animals and humans. The intestines of animals also represent an ideal environment for the selection and transfer of antimicrobial resistance genes. The aim of this study was to investigate the resistance of E. coli isolated from chicken fecal samples to fluoroquinolones and to analyze the characterization of mutations in its gyrA and parC gene related resistance. One hundred and twenty-eight E. coil isolates showed a high resistance to ciprofloxacin (CIP; $60.2\%$), enrofloxacin (ENO; $73.4\%$) and norfloxacin (NOR; $60.2\%$). Missense mutation in gyrA was only found in the amino acid codons of Ser-83 or Asp-87. A high percentage of isolates ($60.2\%$) showed mutations at both amino acid codons. Missense mutation in parC was found in the amino acid codon of Ser-80 or Glu-84, and seven isolates showed mutations at both amino acid codons. Isolates with a single mutation in gyrA showed minimal inhibitory concentrations (MIC) for CIP (${\le}0.5\;to\;0.75{\mu}g/ml$), ENO (1 to $4{\mu}g/ml$) and NOR (0.75 to $4{\mu}g/ml$). These MIC were level compared to isolates with two mutations, one in gyrA and one in parC, and three mutations, one in gyrA and two in parC (CIP, ${\le}0.5\;to\;3{\mu}g/ml;\;ENO,\;2\;to\;32<{\mu}g/ml;\;NOR,\;1.5\;to\;6\;{\mu}g/ml$). However, the isolates with two mutation in gyrA regardless of whether there was a mutation in parC showed high MIC for the three fluoroquinolones (CIP, 0.75 to $32{\le}{\mu}g/ml;\;ENO,\;3\;to\;32{\le}{\mu}g/ml;\;NOR,\;3\;to\;32{\le}{\mu}g/ml$). Interestingly, although the E. coil used in this study was isolated from normal flora of chicken, not clinical specimens, a high percentage of isolates showed resistance to fluoroquinolones and possessed mutations at gyrA and parC associated with fluoroquinolone resistance.

• 생명과학회지
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• 제32권2호
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• pp.94-100
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• 2022

B형간염바이러스(HBV)의 만성 감염은 간경화와 간세포암 발생 빈도를 현저히 높인다. HBV 감염의 임상적 결과는 숙주 유전적 요인과 바이러스의 유전자 변이, 그리고 환경적 요인 등에 결정된다. HBV 복제를 위한 HBV의 pre-genomic RNA 전사는 바이러스의 core promoter 활성화에 의해 조절된다. Core promoter 돌연변이는 급성간 질환과 간세포암 발생에 연관되어 있다. 본 연구팀은 미얀마의 HBV 감염 환자들로부터 바이러스 유전자를 획득하여 core promoter 부위의 유전자 변이들을 파악하였다. Core promoter의 상대적 유전자 활성 차이를 분석하기 위해서 core promoter를 luciferase reporter에 재조합한 시스템을 제작하였다. 분석한 core promoter의 유전자 변이들 중에서 C1731T와 G1806A 돌연변이가 HBV core promoter의 전사 활성화를 증가에 관여하였다. 돌연변이 부위를 중심으로 전사 인자들의 가능한 결합 부위 변화를 컴퓨터 프로그램 분석을 통해 조사한 결과, C/EBPβ와 XBP1 반응 부위가 새롭게 생성되었음을 도출하였다. C/EBPβ의 세포 내 발현은 C1713T 돌연변이를 가진 core promoter의 전사 활성을 증가시켰으며, XBP1 발현은 G1806A 돌연변이를 함유한 M95 promoter를 활성을 증가시켰다. HBV 감염의 치료는 약제 내성과 백신 회피 돌연변이 발생으로 문제점을 가지고 있는 상황에서, 이 연구 결과는 HBV core promoter 돌연변이의 분자생물학적 그리고 임상학적 중요성을 제공한다.

• Asian-Australasian Journal of Animal Sciences
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• 제20권7호
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• pp.1023-1029
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• 2007

Inhibins participate in the regulation of pituitary follicle-stimulating hormone synthesis and secretion, follicular maturation and steroidogenesis in the female. Inhibin ${\beta}_A$ gene (INHBA) was studied as a candidate gene for the prolificacy of sheep. Single nucleotide polymorphisms of the entire coding region and partial 3' untranslated region of INHBA were detected by PCR-SSCP in two high fecundity breeds (Small Tail Han and Hu sheep) and six low fecundity breeds (Dorset, Texel, German Mutton Merino, South African Mutton Merino, Chinese Merino and Corriedale sheep). Only the PCR products amplified by primers 3, 4 and 5 displayed polymorphisms. For primer 3, genotype CC was only detected in Chinese Merino sheep, genotype AA was detected in the other seven sheep breeds. Genotype BB was only detected in Hu sheep. Only Hu sheep displayed polymorphism. Eight or four nucleotide mutations were revealed between BB or CC and AA, respectively, and these mutations did not result in any amino acid change. For primer 4, genotypes EE, EG and GG were detected in Dorset and German Mutton Merino sheep, genotypes EE, EF and FF were detected in Chinese Merino sheep, only genotype EE was detected in the other five sheep breeds. Only Dorset, German Mutton Merino and Chinese Merino sheep displayed polymorphism. Sequencing revealed one nucleotide mutation ($114G{\rightarrow}A$) of exon 2 of INHBA gene between genotype FF and genotype EE, and this mutation did not cause any amino acid change. Another nucleotide change ($143C{\rightarrow}T$) was identified between genotype GG and genotype EE, and this mutation resulted in an amino acid change of $serine{\rightarrow}leucine$. For primer 5, genotypes KK and KL were detected in German Mutton Merino and Corriedale sheep, genotypes KK, LL and KL were detected in the other six sheep breeds. Genotype MM was only detected in Hu sheep. All of these eight sheep breeds displayed polymorphism. Sequencing revealed one nucleotide mutation ($218A{\rightarrow}G$) of exon 2 of the INHBA gene between genotype LL and genotype KK, and nine nucleotide mutations between genotype MM and genotype KK. These mutations did not alter amino acid sequence. The partial sequence (395 bp for exon 1 and 933 bp for exon 2) of the INHBA gene in Small Tail Han sheep (with genotype KK for primer 5) was submitted into GenBank (accession number EF192431). Small Tail Han sheep displayed polymorphisms only in the fragment amplified by primer 5. The Small Tail Han ewes with genotype LL had 0.53 (p<0.05) or 0.63 (p<0.05) more lambs than those with genotype KL or KK, respectively. The Small Tail Han ewes with genotype KL had 0.10 (p>0.05) more lambs than those with genotype KK.

• Asian Pacific Journal of Cancer Prevention
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• 제15권18호
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• pp.7589-7595
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• 2014

Apurinic/apyrimidinic endonuclease 1 (APEX1) is a multifunctional protein which plays a central role in the BER pathway. APEX1 gene being highly polymorphic in cancer patients and has been indicated to have a contributive role in Apurinic/apyrimidinic (AP) site accumulation in DNA and consequently an increased risk of cancer development. In this case-control study, all exons of the APEX1 gene and its exon/intron boundaries were amplified in 530 breast cancer patients and 395 matched healthy controls and then analyzed by single-stranded conformational polymorphism followed by sequencing. Sequence analysis revealed fourteen heterozygous mutations, seven 5'UTR, one 3'UTR, two intronic and four missense. Among identified mutations one 5'UTR (rs41561214), one 3'UTR (rs17112002) and one missense mutation (Ser129Arg, Mahjabeen et al., 2013) had already been reported while the remaining eleven mutations. Six novel mutations (g.20923366T>G, g.20923435G>A, g.20923462G>A, g.20923516G>A, 20923539G>A, g.20923529C>T) were observed in 5'UTR region, two (g.20923585T>G, g.20923589T>G) in intron1 and three missense (Glu101Lys, Ala121Pro, Ser123Trp) in exon 4. Frequencues of 5'UTR mutations; g.20923366T>G, g.20923435G>A and 3'UTR (rs17112002) were calculated as 0.13, 0.1 and 0.1 respectively. Whereas, the frequency of missense mutations Glu101Lys, Ser123Trp and Ser129Arg was calculated as 0.05. A significant association was observed between APEX1 mutations and increased breast cancer by ~9 fold (OR=8.68, 95%CI=2.64 to 28.5) with g.20923435G>A (5'UTR), ~13 fold (OR= 12.6, 95%CI=3.01 to 53.0) with g.20923539G>A (5'UTR) and~5 fold increase with three missense mutations [Glu101Lys (OR=4.82, 95%CI=1.97 to 11.80), Ser123Trp (OR=4.62, 95%CI=1.7 to 12.19), Ser129Arg (OR=4.86, 95%CI=1.43 to 16.53)]. The incidence of observed mutations was found higher in patients with family history and with early menopause. In conclusion, our study demonstrates a significant association between germ line APEX1 mutations and breast cancer patients in the Pakistani population.

• Journal of Genetic Medicine
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• 제12권2호
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• pp.109-117
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• 2015

Purpose: Mitochondrial diseases are clinically and genetically heterogeneous disorders, which make their exact diagnosis and classification difficult. The purpose of this study was to identify pathogenic mitochondrial DNA (mtDNA) mutations in 2 Korean families with myoclonic epilepsy with ragged-red fibers (MERRF) and Leigh syndrome, respectively. Materials and Methods: Whole mtDNAs were sequenced by the method of mtDNA-targeted next-generation sequencing (NGS). Results: Two causative mtDNA mutations were identified from the NGS data. An m.8344A>G mutation in the tRNA-Lys gene (MT-TK) was detected in a MERRF patient (family ID: MT132), and an m.9176T>C (p.Leu217Pro) mutation in the mitochondrial ATP6 gene (MT-ATP6) was detected in a Leigh syndrome patient (family ID: MT130). Both mutations, which have been reported several times before in affected individuals, were not found in the control samples. Conclusion: This study suggests that mtDNA-targeted NGS will be helpful for the molecular diagnosis of genetically heterogeneous mitochondrial diseases with complex phenotypes.

• Asian Pacific Journal of Cancer Prevention
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• 제16권12호
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• pp.4869-4872
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• 2015

Background: Mutations of the FMS-like tyrosine kinase-3 (FLT3) receptor gene may promote proliferation via activation of multiple signaling pathways. FLT3-internal tandem duplication (FLT3-ITD) is the most common gene alteration found in patients diagnosed with acute myeloid leukaemia (AML) and has been associated with poor prognosis. Materials and Methods: We performed mutational analysis of exons 14-15 and 20 of the FLT3 gene in 54 AML patients using PCR-CSGE (conformational sensitive gel electrophoresis) followed by sequencing analysis to characterise FLT3 mutations in adult patients diagnosed with AML at Hospital USM, Kelantan, Northeast Peninsular Malaysia. Results: FLT3 exon 14-15 mutations were identified in 7 of 54 patients (13%) whereas no mutation was found in FLT3 exon 20. Six ITDs and one non-ITD mutation were found in exon 14 of the juxtamembrane (JM) domain of FLT3. FLT3-ITD mutations were associated with a significantly higher blast percentage (p-value = 0.008) and white blood cell count (p-value = 0.023) but there was no significant difference in median overall survival time for FLT3-ITD+/FLT3-ITD- within 2 years (p-value = 0.374). Conclusions: The incidence of FLT3-ITD in AML patients in this particular region of Malaysia is low compared to the Western world and has a significant association with WBC and blast percentage.