• Journal of Microbiology and Biotechnology
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• 제24권2호
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• pp.144-151
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• 2014

Increasing the gene copy number has been commonly used to enhance the protein expression level in the yeast Pichia pastoris. However, this method has been shown to be effective up to a certain gene copy number, and a further increase of gene dosage can result in a decrease of expression level. Evidences indicate the gene dosage effect is product-dependent, which needs to be determined when expressing a new protein. Here, we describe a direct detection of the gene dosage effect on protein secretion through expressing the enhanced green fluorescent protein (EGFP) gene under the direction of the ${\alpha}$-factor preprosequence in a panel of yeast clones carrying increasing copies of the EGFP gene (from one to six copies). Directly examined under fluorescence microscopy, we found relatively lower levels of EGFP were secreted into the culture medium at one copy and two copies, substantial improvement of secretion appeared at three copies, plateau happened at four and five copies, and an apparent decrease of secretion happened at six copies. The secretion of EGFP being limiting at four and five copies was due to abundant intracellular accumulation of proteins, observed from the fluorescence image of yeast and confirmed by western blotting, which significantly activated the unfolded protein response indicated by the up-regulation of the BiP (the KAR2 gene product) and the protein disulfide isomerase. This study implies that tagging a reporter like GFP to a specific protein would facilitate a direct and rapid determination of the optimal gene copy number for high-yield expression.

• Journal of Genetic Medicine
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• 제6권2호
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• pp.146-154
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• 2009

Multiplex ligation dependent probe amplification (MLPA)은 탐침자를 표적지에 교잡시킨 후, ligation 시키고, 그 산물을 중합효소연쇄반응으로 증폭시킴으로써 표적지의 존재여부 또는 농도를 확인할 수 있는 방법으로, 그 원리가 소개된 이래로 여러 유전자들에 대한 거대결실 및 중복돌연변이에 대한 탐색에 이용되었다. 유전자진단은 질환에 관련된 유전자에 대한 돌연변이를 탐색함으로써 질환을 진단하는 방법으로, 단일유전자 결핍 질환에 대한 유전자진단은 주로 중합효소연쇄반응과 염기서열 분석 방법을 통한 점돌연변이의 탐색에 집중되어 있다. 거대결실 또는 중복돌연변이의 경우, 특히 이형접합자를 형성하게 되는 경우는 중합효소 연쇄반응을 통하여 결실 또는 중복돌연변이 여부의 확인이 힘들다. PCR 방법에 기초하여 유전자의 농도(gene dosage)를 알 수 있는 방법으로 MLPA 방법이 소개되면서 거대결실 또는중복돌연변이를 포함하고 있던 질병 관련돌연변이들의 규명이 한층 쉬워졌다. MLPA의 원리를 응용하여 단순한 유전자의 농도 측정뿐 아니라 유전자내의 메칠화양상의 차이를 확인하거나, 염색체의 배수체 이상 등 염색체이상의 돌연변이 규명과, 전체 유전자의 크기가 비교적 커서 거대결실 돌연변이를 많이 동반하는, 주로 우성유전의 암 관련 유전자 돌연변이의 규명에 유용하게 이용된다. MLPA는 상용적인 중합효소연쇄반응으로 확인할 수 없는 유전자의 농도를 효과적으로 규명할 수 있는 방법으로, 적은 양의 주형 DNA만을 사용하고, 한가지의 실험원리로 다양한 응용이 가능하며 high-throughput이 가능한 장점을 가지는 반면, 주형 DNA의 질에 결과의 의존도가 높고, 민족 또는 개인간의 차이를 보일 수 있는 표적 DNA 염기서열 내의 single nucleotide polymorphism (SNP) 등으로 인해 분석의 오류가 생길 수 있으며, 양적 차이를 규명하는 것이므로 수 차례의 대조군 검사가 함께 진행되어야 하는 단점이 있다. 여기서는 MLPA를 이용하여 질병유전자의 돌연변이를 밝힌 사례를 바탕으로 MLPA의 원리와 탐색할 수 있는 돌연변이의 종류, 그리고 이 방법의 장단점에 대해 고찰해 보고자 한다.

• Journal of Microbiology and Biotechnology
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• 제15권5호
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• pp.1125-1129
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• 2005

Cloning of a 6.6-kb BamHI digested chromosomal DNA from S. griseus IFO13350 revealed the presence of an additional gene encoding a novel trypsin-like enzyme, named SprU. The SprU protein shows a high homology ($79\%$ identity, $88\%$ similarity) with the SGT protease, which has been reported as a bacterial trypsin in the same strain. The amino acid sequence deduced from the nucleotide sequence of the sprU gene suggests that SprU is produced as a precursor consisting of an amino-terminal presequence (29 amino acid residues), prosequence (4 residues), and mature trypsin consisting of 222 amino acids with a molecular weight of 22.94 kDa and a calculated pI of 4.13. The serine, histidine, and aspartic acid residues composing the catalytic triad of typical serine proteases are also well conserved. When the trypsin activity of the SprU was spectrophotometrically measured by the enzymatic hydrolysis of the artificial chromogenic substrate, N-${alpha}$-benzoyl-DL-arginine-p-nitroanilide, the S. lividans transformant with pWHM3-U gave 3 times higher activity than that of control. When the same recombinant plasmid was introduced into S. griseus, however, the gene dosage effect was not so significant, as in the cases of other genes encoding serine proteases, such as sprA, sprB, and sprD. Although two trypsins, SprU and SGT, have a high degree of homology, the pI values, the gene dosage effect in S. griseus, and the gene arrangement adjacent to the two genes are very different, suggesting that the biochemical and biological function of the SprU might be quite different from that of the SGT.

• Toxicological Research
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• 제20권1호
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• pp.21-29
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• 2004

We used cDNA microarray to assess gene expression profiles in hematopoetic cell line, U-937, exposed to low doses of ionizing irradiation. The 1,000 DNA elements on this array were PCR-amplified cDNAs selected from named human cancer related genes. According to the strength of irradiation, the levels of some gene expression were increased or decreased as dose-dependent manner. The gene expressions of Tubulin alpha, protein kinase, interferon-alpha, -beta, -omega receptor and ras homolog gene family H were significantly increased. Especially, Tubulin gene was shown 2.5 fold up-regulated manner under stress of 500 rad irradiation than 200 rad. On the other hand, fibroblast growth factor 12 and four and a half LIM domains, etc. were significantly down-regu-lated. Also, tumor protein 53(TP53) related genes that p53 inducible protein, tumor protein 53-binding protein looks of little significance as radiation sensitive manner. The radio-sensitivity of tubulin gene etc. that we proposed could be useful to rapid and correct survey for the bio-damage by exposure to low dose irradiation.

• Parasites, Hosts and Diseases
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• 제51권2호
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• pp.147-154
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• 2013

To control coccidiosis without using prophylactic medications, a DNA vaccine targeting the gametophyte antigen Gam56 from Eimeria maxima in chickens was constructed, and the immunogenicity and protective effects were evaluated. The ORF of Gam56 gene was cloned into an eukaryotic expression vector pcDNA3.1(zeo)+. Expression of Gam56 protein in COS-7 cells transfected with recombinant plasmid pcDNA-Gam56 was confirmed by indirect immunofluorescence assay. The DNA vaccine was injected intramuscularly to yellow feathered broilers of 1-week old at 3 dosages (25, 50, and $100{\mu}g/chick$). Injection was repeated once 1 week later. One week after the second injection, birds were challenged orally with $5{\times}10^4$ sporulated oocysts of E. maxima, then weighed and killed at day 8 post challenge. Blood samples were collected and examined for specific peripheral blood lymphocyte proliferation activity and serum antibody levels. Compared with control groups, the administration of pcDNA-Gam56 vaccine markedly increased the lymphocyte proliferation activity (P<0.05) at day 7 and 14 after the first immunization. The level of lymphocyte proliferation started to decrease on day 21 after the first immunization. A similar trend was seen in specific antibody levels. Among the 3 pcDNA-Gam56 immunized groups, the median dosage group displayed the highest lymphocyte proliferation and antibody levels (P<0.05). The median dosage group had the greatest relative body weight gain (89.7%), and the greatest oocyst shedding reduction (53.7%). These results indicate that median dosage of DNA vaccine had good immunogenicity and immune protection effects, and may be used in field applications for coccidiosis control.

• 한국양식학회지
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• 제10권4호
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• pp.409-415
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• 1997

The carp $\beta$-actin regulatory sequences and RSV/LTR promoter were tested whether they are functinal to express linked structure gene (chloramphenicol acetyltransferas, CAT) in olive flounder (Paralichthys olivaceus) by determining the patterns of gene expression following intramuscular in vivo direct injection. The injection experiments with various concentrations of both pRSVCAT and pFV4CAT clearly revealed the effectiveness of DNA dosage on expression of CAT. The increase of CAT activity was linear in both plasmids, and maximal CAT activity was obtained with 100 ug of pFV4CAT injection. The amounts of CAT expression with pFV4CAT-injected fist were higher than those with pRSVCAT-injected fish. CAT activity was readily detectable as early as one day after injection, slightly increased at day 2, and declined over time. Most amount of DNA intramuscularly injected into olive flounder muscles persisted extrachromosomally without showing any integrated or replicated form in vivo.

• Genomics & Informatics
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• 제4권1호
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• pp.16-22
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• 2006

The KFDA (Korea Food & Drug Administration) has performed a collaborative toxicogenomics project since 2003. Its aim is to construct a toxicology database of 12 compounds administered to mice at initial phase. We chose 6-MP (6-mercaptopurine) which has been used in the treatment of childhood leukemia. It was administered at low (0.224 mg/kg) and at high (2.24 mg/kg) dose (5 mice per group) intraperitonealy to the postnatal 6 weeks mice, then the serum and liver were collected at the indicated time (6, 24 and 72 h) after scarification. Serum biochemical markers for liver toxicity were measured and histopathologic studies also were carried out. The gene expression profiling was carried out by using Applied Biosystems 1700 Full Genome Expression Mouse. By self-organization maps (SOM), we identified groups with unique gene expression patterns, some of them are supposed to be related to 6-MP induced toxicity, including lipid metabolism abnormality, inflammatory response, oxidative stress, ATP depletion and cell death. The potential toxic effects appearing as gene expression changes are dependent of the time of 6-MP but independent of the dosage of it. This study would contribute to establishment of international database as well as national one about hepatotoxicity.

• Biotechnology and Bioprocess Engineering:BBE
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• 제9권6호
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• pp.523-527
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• 2004

Recombinant Saccharomyces cerevisiae expression systems were developed to pro­duce a novel human anti-angiogenic protein called LK8, an 86 amino-acid kringle fragment pro­tein with three disulfide linkages. Galactose-inducible LK8 expression plasmid was constructed, and LK8 production levels by four S. cerevisiae strains were compared in order to select an op­timal host strain. S. cerevisiae 2805 was the most efficient among the strains tested. Elevating the LK8 gene copy number through multiple integration using 8-sequences as target sites re­sulted in more than a two-fold increase in the LK8 production level compared with the plasmid­based expression system. The maximum LK8 protein concentration of 25 mg/L was obtained from batch cultivation of the yeast transformant that harbors 16 copies of the LK8 gene. In con­clusion, the strain integrated with the multiple LK8 gene secreted the protein with relatively high yield, although, the increased LK8 gene dosage over 11 copies did not lead to further en­hancement in batch cultivations.

• 식물조직배양학회지
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• 제21권2호
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• pp.99-103
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• 1994

비선택성 제초제인 bialaphos는 고등식물에 있어서 glutamine 합성을 억제하여 식물체를 고사 시키는 능력을 갖고 있다. 본 연구에서 acetylteansferase에 의해 encoding된 bialaphos 저항성 유전자(bar gene)는 세균(Pseudomonas sryngae pv tabaci)의 genomic DNA로부터 cloning된 것을 사용하였다. 수분시킨 담배의 화계에 일정한 시간별로 bar 유전자를 처리한 결과 수분 후 30-40시간 사이의 처리구 에서 형질전환 식물체가 가장 많이 얻어 졌다. 그러한 형질전환 식물체의 kanamycin과 bialaphos 저항성 형질은 자식후대(T$_1$, T$_2$)에 있어서도 우성형질로 유전되었으나 wild type의 담배는 상기의 약제를 처리 하였을때 전부 고사하였다. 그리고, T$_1$세대의 형질전환 식물체로부터 전 염색체 DNA를 추출하여 Southern 분석한 결과 bar 유전자가 식물의 염색체상에 안정하게 존재하는 것을 확인하였다. 이상의 결과로부터 담배의 수분, 수정 시기에 외부유전자인 bar를 화주에 처리함으로써 bialaphos 저항성 식물을 만들어낼 수 있었다.

• 한방재활의학과학회지
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• 제30권4호
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• pp.17-30
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• 2020

Objectives The purpose of this study is to evaluate the healing effect of Yukmijihwang-tang (YM) on femur fractured mice. Methods Mice were randomly divided into 6 groups: normal, control, positive control, YM with low, medium, high dosage each. All groups were prepared with femur fracture and treated diffrently. In order to measure bone regeneration effects, we analysed the levels of cyclooxygenase-2 (COX2), bone morphogenetic protein-2 (BMP2), collagen type II alpha 1 chain (Col2a1), Sox9, runt-related transcription factor 2 (Runx2), and osterix genes expressed in bone. For morphological analysis, muscles were removed and femur was observed with naked eye. Results COX2 gene expression in bone marrow significantly decreased. BMP2 gene expression significantly increased. Col2a1 gene expression significantly increased. Sox9 gene expression increased as well. Runx2 gene expression in bone marrow increased, but there was no statistical significance. Osterix gene expression significantly increased. Union of the fracture site progressed more in YM group compared to the control group. The fracture union score was significantly decreased in YM group compared to the control group. Conclusions YM showed anti-inflammatory effect, promoted bone regeneration by stimulating the bone regeneration factor. In conclusion, YM can help fracture healing and it well be applied clinically to patients with fracture.