• Title/Summary/Keyword: Gene Screening

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Molecular Cloning and Expression of Human Dihydrolipoamide Dehydrogenase-Binding Protein in Excherichia coli

  • Lee, Jeong-Min;Ryou, Chong-Suk;Kwon, Moo-Sik
    • Journal of Microbiology and Biotechnology
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    • v.11 no.4
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    • pp.592-597
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    • 2001
  • The pyruvate dehydrogenase complex (PDC) catalyzes the oxidative decarboxylation of pyruvate with the formation of $CO_2$, acetyl-CoA, NADH, and H+. This complex contains multiple copies of three catalytic components including pyruvate dehydrogenase(E1), dihydrolipoamide acetyltransferase(E2), and dihydrolipoamide dehydrogenase (E3). Two regulatory components (E1-kinase and phospho-E1 phosphatase) and functionally less-understood protein (protein X, E3BP) are also involved in the formation of the complex. In this study, cloning and characterization of a gene for human E3BP have been carried out. A cDNA encoding the human E3BP was isolated by database search and cDNA library screening. The primary structure of E3BP has some similar characteristics with that of E2 in the lipoyl domain and the carboxyl-terminal domain, based on the nucleotide sequence and the deduced amino acid sequence. However, the conserved amino acid moiety including the histidine residue for acetyltransferase activity in E2 is not conserved in the case of human E3BP. The human E3BP was expressed and purified in E. coli. The molecular weight of the protein, excluding the mitochondrial target sequence, was about 50 kDa as determined by SDS-PAGE. Cloning of human E3BP and expression of the recombinant E3BP will facilitate the understanding of the role(s) of E3BP in mammalian PDC.

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HtrA2 Interacts with Aβ Peptide but Does Not Directly Alter Its Production or Degradation

  • Liu, Meng-Lu;Liu, Ming-Jie;Kim, Jin-Man;Kim, Hyeon-Jin;Kim, Jeong-Hak;Hong, Seong-Tshool
    • Molecules and Cells
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    • v.20 no.1
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    • pp.83-89
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    • 2005
  • HtrA2/Omi is a mammalian mitochondrial serine protease homologous to the E. coli HtrA/DegP gene products. Recently, HtrA2/Omi was found to have a dual role in mammalian cells, acting as an apoptosis-inducing protein and being involved in maintenance of mitochondrial homeostasis. By screening a human brain cDNA library with $A{\beta}$ peptide as bait in a yeast two-hybrid system, we identified HtrA2/Omi as a binding partner of $A{\beta}$ peptide. The interaction between $A{\beta}$ peptide and HtrA2/Omi was confirmed by an immunoblot binding assay. The possible involvement of HtrA2/Omi in $A{\beta}$ peptide metabolism was investigated. In vitro peptide cleavage assays showed that HtrA2/Omi did not directly promote the production of $A{\beta}$ peptide at the ${\beta}/{\gamma}$-secretase level, or the degradation of $A{\beta}$ peptide. However, overexpression of HtrA2/Omi in K269 cells decreased the production of $A{\beta}40$ and $A{\beta}42$ by up to 30%. These results rule out the involvement of HtrA2/Omi in the etiology of Alzheimer's disease. However, the fact that overexpression of HtrA2/Omi reduces the generation of $A{\beta}40$ and $A{\beta}42$ suggests that it may play some positive role in mammalian cells.

Population analysis of the toxic dinoflagellate genus Alexandrium by novel molecular markers

  • Kim, Choong-jae;Kim, Sook-Yang;Kim, Kui-Young;Kang, Young-Sil;Kim, Hak-Gyoon;Kim, Chang-Hoon
    • Proceedings of the Korean Aquaculture Society Conference
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    • 2003.10a
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    • pp.134-135
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    • 2003
  • The geographic expansion of the toxic dinoflagellates genus Alexandrium has been shown to be world wide ranging. The members of the genus Alexandrium ocnstituted of 20-30 species did not show substantial differences in their morphology, which is mostly referred in the 'tamarensis species complex', except some species. Though rDNA sequences variations are very few and pseudogene types are so diverse that it is difficult to use them as the specific markers. In this study, we outlined Korean and Japanese A, tamarense and A. catenella regional isolates by phylogenetic analysis inferred from no cutting alignments of LSU rDNA D1-D2 and SSU rDNA sequences to group these regional isolates. The results were compared to RFLP patterns of PCR products targeted chloroplast DNA. Lastly screening of highly repeated microsatellite DNA which is frequently used for population analysis in eukaryotes was conducted. A. catenella regional strains identified by the sequencing of rDNA D1-D2 domain were divided into at least 3 groups of type E, CMC and Chinese type, divergence root may not be deep comparing with that of A. tamarense whose pseudogenes are very variable. Results of RFLP pattern and the phylogeny of the unknown gene targeting chloroplast showed that Korean and Japanese A. catenella regional isolates were divided into 3 types: Korean, Japanese and the third CMC types. Population-specific PCR amplification with Japanese A. catenella type-specific PCR primers was useful method for population analysis of A. catenella. Various types of satellite sequences such as 5 nucleotides repeats were obtained from A. tamarense and A. catenella. The 5 nucleotides repeats were primed at the both 3'and 5' ends, and these repeats were prominent as longer repeated motifs. This repeated DNA was intercalated as internal sequences containing various types subrepeats. It is expected that these satellite DNA would be a useful molecular population marker through detail comparison among Alexandrium regional isolates to trace their transferring pathway and to prevent their human-associated their regional extents.

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Integration Sites and Genotype Distributions of Human Papillomavirus in Cervical Intraepithelial Neoplasia

  • Wang, Li;Dai, Shu-Zhen;Chu, Hui-Jun;Cui, Hong-Fei;Xu, Xiao-Yan
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.6
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    • pp.3837-3841
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    • 2013
  • Objectives: To analyse HPV integration prevalence and genotype distributions in cervical intraepithelial neoplasia (CIN) in east part of China, furthermore to assess preferential sites for common HPV integrations and provide baseline information for cervical abnormality screening and prevention. Methods: Integration of HPV in 113 paraffin-embedded cervical intraepithelial neoplasia samples was assessed using Gencap technology in Key Laboratory of Biotechnologies in BGI-Shenzhen. Results: 64 samples were HPV-integrated and as the cervical lesions increased, the integration rate became higher significantly (P=0.002). Fifteen different HPV genotypes were detected, 14 high-risk (16, 18, 31, 33, 51, 52, 56, 58, 66, 68) and 1 low-risk (11). The most common genotypes were HPV-16, 58, 33, 52, 66, and 56. Thirteen patients had co-integration involving mainly HPV-16 and 58. The frequency of HPV gene disruption was higher in L1 and E1 genes than in other regions of the viral genomes. Conclusion: Some 56.6% of CIN lesions in Qingdao had HPV integrations, and 67.2% of HPV-integrated patients were HPV-16 and 58, more prone to be integrated in younger patients below 45 years old. There exist preferential sites for HPV-16 and HPV-58 integration, and they are more likely to be disrupted in the L1 and E1 loci.

P53 Polymorphism at Codon 72 is Associated with Keratocystic Odontogenic Tumors in the Thai Population

  • Yanatatsaneejit, Pattamawadee;Boonsrang, Ajaree;Mutirangura, Apiwat;Patel, Vyomesh;Kitkumthorn, Nakarin
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.5
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    • pp.1997-2001
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    • 2015
  • Objective: To clarify the association between the p53 polymorphism at codon 72 and susceptibility to the sporadic keratocystic odontogenic tumor (KCOT). Design: One hundred KCOTs and 160 match-group healthy controls were genotyped to ascertain the frequency of the p53 codon 72 polymorphism using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), confirmed by direct sequencing. Results: The frequencies of the Pro/Pro, Arg/Pro, and Arg/Arg genotypes were 23.8%, 49.4%, and 26.9%, respectively, in the controls, while the KCOT cohort demonstrated 43.0%, 39.0%, and 18.0%, respectively. Further analysis suggested that p53 Pro could be a KCOT-susceptible allele (OR (95%CI)=1.77 (1.22 to 2.59), p=0.0024), with a sex-adjusted OR (95%CI) of 1.71 (1.17-2.50), p=0.0046. Moreover, the results indicated that p53 codon 72 Pro homozygous was associated with a two-fold risk of developing KCOT (adjusted OR (95%CI) =2.17(1.23-3.84), p=0.0062). Conclusions: The C/C genotype of P53 gene codon 72 increases the risk of developing sporadic KCOT and may be a useful tool for screening and diagnostic purposes.

Gibberellins Production and Identification of Endophytic Fungi Isolated from Aquatic Plant in Fresh Water (담수에 자생하는 수생식물에서 분리된 내생균류의 지베렐린 생산과 동정)

  • You, Young-Hyun;Kang, Sang-Mo;Choi, Yu-Mi;Lee, Myung-Chul;Kim, Jong-Guk
    • The Korean Journal of Mycology
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    • v.43 no.1
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    • pp.71-76
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    • 2015
  • Aquatic plant Hydrocharis dubia (Blume) Backer was collected from the Dalsung wetland in Daegu. Sixteen endophytic fungi with different colony morphologies were isolated from the roots of aquatic plants. Waito-c rice (WR) seedlings were treated with fungal culture filtrates (FCF) for screening plant growth-promoting activity. In the results, HD1008 strain isolated from aquatic plant showed highest plant growth-promoting activity. The FCF of HD1008 strain was analyzed using gas chromatography mass spectrometry (GC/MS) with selected ion monitoring (SIM). Analysis of the FCF of HD1008 strain found that it contained gibberellins (GA) ($GA_1$, 1.2 ng/100 mL; $GA_4$, 5 ng/100 mL). Phylogenetic tree of HD1008 strain was constructed by partial internal transcribed spacer (ITS) region and partial beta-tubulin gene sequences. Therefore, we describe HD1008 strain as a new gibberellin-producing Penicillium trzebinskii based on morphological and molecular characteristics.

Immunohistochemical Detection of p53 Gene Mutation in Urine Samples in the Patients with Bladder Cancer (방광암 환자의 요세포 검사에서 p53 단백 발현의 의의)

  • Lee, Sang-Sook;Bae, Ji-Yeon;Kang, Yu-Na;Cho, Young-Rok;Park, Nam-Jo;Kim, Seun-Young;Kim, Jung-Hi
    • The Korean Journal of Cytopathology
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    • v.7 no.2
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    • pp.144-150
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    • 1996
  • Although bladder cancers are very common, little is known about their molecular pathogenesis. It is known that p53 alteration is found in about 60% of muscle-invasive bladder cancer, necessiating aggressive therapy and poor outcome. We examined the nuclear expression of p53 protein, using D07 monoclonal antibody in the urine samples from 31 patients with transitional cell carcinoma of the bladder to investigate the correlation of p53 overexpression with histologic grades and depth of invasion. The positive rate of p53 protein was 27% in superficial bladder tumor, but increased up to 71% in the invasive bladder carcinomas. The overexpression of p53 protein increased according to Mostofi grading system from 18% in grade I, 45% in grade II, and up to 100% in grade III. The p53 expression tended to be higher in the invasive and high grade bladder cancers than in the superficial and low grade ones(p<0.05). These results suggest that immunohistochemical analysis of the urine specimen in the bladder cancer patients could be a useful method of screening for the presence of p53 mutant protein. The mutant p53 protein expression may be an indicator of bladder cancer with more proliferative potential and/or aggressive biologic behavior.

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Isolation and characterization of an antifungal substance from Burkholderia cepacia, an endophytic bacteria obtained from roots of cucumber.

  • Park, J.H.;Park, G.J.;Lee, S.W;Jang, K.S.;Park, Y.H.;Chung, Y.R.;Cho, K.Y.;Kim, J.C.
    • Proceedings of the Korean Society of Plant Pathology Conference
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    • 2003.10a
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    • pp.95.2-96
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    • 2003
  • In order to develop a new microbial fungicide for the control of vegetable diseases using endophytic bacteria, a total of 260 bacterial strains were isolated from fresh tissues of 5 plant species. After they were cultured in broth media, their antifungal activities were screened by in vivo bioassays against Botrytis cinerea(tomato gray mold), Pythium ultimum(cucumber damping-off), Phytopkhora infestans(tomato late blight), Colletotrichum orbiculare(cucumber anthracnose), and Blumeria graminis f. sp. hordei(barley powdery mildew). As the results of screening, 38 bacterial strains showed potent antifungal activities against at least one of 5 plant pathogens. A bacterial strain EB072 displayed potent disease control activities against 3 plant diseases. Among the bacterial strains with a potent antifungal activity against cucunlber anthracnose, three bacterial strains, EB054, EB151 and EB215, also displayed a potent in vitro antifungal activity against C. acutatum, a fungal agent causing pepper anthracnose. A bacterial strain EB215 obtained from roots of cucumber was identified as Burkholderia cepacia based on its physiological and biochemical characteristics and 165 rRNA gene sequence. An antifungal substance was isolated from the liquid cultures of B. cepacia EB215 strain by ethyl acetate partitioning, repeated silica gel column chromatography, and invitro bioassay, Its structural determination is in progress by various instrumental analyses.

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New surveillance concepts in food safety in meat producing animals: the advantage of high throughput 'omics' technologies - A review

  • Pfaffl, Michael W.;Riedmaier-Sprenzel, Irmgard
    • Asian-Australasian Journal of Animal Sciences
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    • v.31 no.7
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    • pp.1062-1071
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    • 2018
  • The misuse of anabolic hormones or illegal drugs is a ubiquitous problem in animal husbandry and in food safety. The ban on growth promotants in food producing animals in the European Union is well controlled. However, application regimens that are difficult to detect persist, including newly designed anabolic drugs and complex hormone cocktails. Therefore identification of molecular endogenous biomarkers which are based on the physiological response after the illicit treatment has become a focus of detection methods. The analysis of the 'transcriptome' has been shown to have promise to discover the misuse of anabolic drugs, by indirect detection of their pharmacological action in organs or selected tissues. Various studies have measured gene expression changes after illegal drug or hormone application. So-called transcriptomic biomarkers were quantified at the mRNA and/or microRNA level by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) technology or by more modern 'omics' and high throughput technologies including RNA-sequencing (RNA-Seq). With the addition of advanced bioinformatical approaches such as hierarchical clustering analysis or dynamic principal components analysis, a valid 'biomarker signature' can be established to discriminate between treated and untreated individuals. It has been shown in numerous animal and cell culture studies, that identification of treated animals is possible via our transcriptional biomarker approach. The high throughput sequencing approach is also capable of discovering new biomarker candidates and, in combination with quantitative RT-qPCR, validation and confirmation of biomarkers has been possible. These results from animal production and food safety studies demonstrate that analysis of the transcriptome has high potential as a new screening method using transcriptional 'biomarker signatures' based on the physiological response triggered by illegal substances.

Functional expression of CalB in E.coli (대장균에서의 Candida antarctica lipase B 최적 발현)

  • Kim, Hyun-Sook;Kim, Yong-Hwan
    • KSBB Journal
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    • v.23 no.5
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    • pp.445-448
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    • 2008
  • Candida antarctica lipase B (CalB) is an efficient biocatalyst for many organic synthesis reactions. To make full use of CalB, we need effective expression system. Previously recombinant CalB was successfully expressed in the methylotropic yeast Pichia pastoris. In addition, we succeed in the functional expression of CalB in the Escherichia coli cytoplasm. This CalB expression system in E.coli has many considerable advantages in comparison with other expression systems and enables high-throughput screening of gene libraries as those derived from directed evolution experiments. To optimize E.coli system, we investigate comparing between OrigamiB (DE3) and BL21 (DE3) and observing effect of IPTG amount.