• 생명과학회지
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• 제14권3호
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• pp.429-434
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• 2004

Zymomonas mobilis 유래 levansucrase 유전자(levU)를 GAL1 promoter 하류에 연결시킨 pYES-levU와 GAL10 promoter 하류에 Kluyveromyces marxianus exoinulinase의 분비 신호서열(INU1 ss) 하류에 연결시킨 pYInu-levU를 각각 구축하였다. 이들 plasmid를 invertase 결손 변이주(suc2-$\Delta$9)인 S. cerevisiae SEY2102에 형질전환시켜 고활성 형질전환주를 선발하였다. 효모 형질전환주를 galactose 함유 배지로 배양한 결과, pYES-levU 함유 형질전환주인 경우 levansucrase의 총활성은 7.17U/ml이고, pYInu-levU 함유 형질전환주인 경우 6.61U/ml에 도달하였다. 발현된 levansucrase 약 50% 정도가 배지와 periplasmic space에 존재하였고, INU1 ss에 의한 분비효율 증가는 관찰할 수 없었다. 또한, 효모에서 발현된 재조합 levansucrase는 과당쇄화된 형으로 생산되는 것으로 보여진다.

• 한국미생물·생명공학회지
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• 제32권3호
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• pp.206-211
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• 2004

Pseudomonas aurantiaca 유래 levansucrase 유전자(lscA)를 GAL1 promoter 하류에 연결시킨 pYES-lscA와 CAL10 promoter와 Kluyveromyces marxianus exoinulinase의 분비 신호서열(INU1 ss)하류에 연결시킨 pYInu-lscA를 각각 구축하였다. 이들 plasmid를 invertase 결손 변이주(suc2-$\Delta$9)인 S. cerevisiae SEY2102에 형질전환시켜 고활성 형질전환주를 선발하였다. 효모 형질전환주를 galactose 함유 배지로 배양한 결과, pYES-lscA 함유 형질전환주인 경우 levansucrase의 총활성은 8.62 U/ml이고, pYInu-lscA 함유 형질전환주인 경우 5.43 U/ml에 도달하였다. 발현된 levansucrase의 약 80% 정도가 periplasmic space와 cytopla느에 존재하였고, INU1 ss에 의한 분비효율 증가는 관찰할 수 없었다. 또한, 효모에서 발현된 재조합 levansucrase는 과당쇄화된 형으로 생산되는 것으로 보여진다.

• 생명과학회지
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• 제20권6호
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• pp.934-939
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• 2010

박테리오신의 항균활성 개선을 위해 선행연구에서 개발된 ADH 프로모터에 의해 박테리오신 유전자를 발현시키는 효모발현 벡터에 GPD 프로모터 단편을 도입하여 강력한 프로모터를 가진 효모발현 재조합 플라스미드DNA를 제작하였다. ADH 프로모터에 의해 박테리오신 유전자를 발현시키는 기존의 형질전환 효모들에 비해 새롭게 개발된 GPD 프로모터에 의해 박테리오신 유전자를 발현시키는 형질전환 효모들이 그람양성 대표세균인 고초균(B. subtilis)과 그람음성 장내세균인 대장균(E. coli) 모두에서 보다 높은 생육억제환을 나타내는 것을 확인 하였다. 이 연구의 결과로 GPD 프로모터에 의해 발현이 유도되는 박테리오신 생산 효모들을 이용하여 부패하기 쉬운 식품들의 보존성을 향상시키기 위한 보존제 대체물질 또는 가축 사료에서 병원균의 생육을 저해하기 위한 항생제 대체물질의 산업적인 생산이 가능하게 될 것으로 기대된다.

• 한국미생물·생명공학회지
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• 제36권3호
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• pp.221-226
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• 2008

효모에서 사람의 H-, L-ferritin을 생산하기 위해서, 기존에 복제된 vector를 사용하였으며,단백질을 발현하기 위해서 각각의 증폭된 ferritin 유전자를 GALI promoter에 의해 조절되는 pYES2.1/V5-His-TOPO 효모 발현 vector에 삽입하였다. Western blot 분석을 통해서 사람의 H-, L-ferritin subunits을 함유한 재조합 효모에서 사람의 ferritin이 발현된 것을 확인할 수 있었다. 또한 Atomic absorption spectrometry(AAS) 분석을 통해서 형질변환된 효모의 철 함유량이 대조군과 비교하여 $1.6{\sim}l.8$배 증가한 것을 확인하였다. 향후 ferritin이 함유된 형질변환 효모를 사용하여 잠재적으로 철이 강화된 영양성분을 기능성 식품과 사료에 이용할 수 있을 것이다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권6호
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• pp.576-581
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• 2005

Phytase improves the bioavailability of phytate phosphorus in plant foods to humans and animals, and reduces the phosphorus pollution of animal waste. We have engineered the cell surface of the yeast. Saccharomyces cerevisiae, by anchoring active fungal phytase on its cell wall, in order to apply it as a dietary supplement containing bioconversional functions in animal foods and a whole cell bio-catalyst for the treatment of waste. The phytase gene (phyA) of Aspergillus niger with a signal peptide of rice amylase 1A (Ramy1A) was fused with the gene encoding the C-terminal half (320 amino acid residues from the C-terminus) of yeast ${\alpha}-agglutinin$, a protein which is involved in mating and is covalently anchored to the cell wall. The resulting fusion construct was introduced into S. cerevisiae and expressed under the control of the constitutive glyceraldehydes-3-phosphate dehydrogenase (GPD) promoter. Phytase plate assay revealed that the surface-engineered cell exhibited a catalytically active opaque zone which was restricted to the margin of the colony. Additionally, the phytase activity was detected in the cell fraction, but was not detected in the culture medium when it was grown in liquid. These results indicate that the phytase was successfully anchored to the cell surface of yeast and was displayed as its active form. The amount of recombinant phytase on the surface of yeast cells was estimated to be 16,000 molecules per cell.

• Journal of Microbiology and Biotechnology
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• 제11권6호
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• pp.915-921
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• 2001

Phytase improves the bioavailability of phytate phosphorus in plant foods to humans and animals, and reduces the phosphorus pollution of animal waste. In order to express a high level of fungal phytase in Saccharomyces cerevisiae, various expression vectors were constructed with different combinations of promoters, translation enhancers, signal peptides, and terminator. Three different promoters fused to the phytase gene (phyA) from Aspergillus niger were tested: a galactokinase (GAL1) promoter, glyceraldehyde-3-phosphate dehydrogenase (GPD) promoter, and yeast hybrid ADH2-GPD promoter consisting of alcohol dehydrogenase II (ADH2) and a GPD promoter. The signal peptides of phytase, glucose oxidase (GO), and rice amylase 1A(RAmy1A) were included. Plus, the translation enhancers of the ${\Omega}$ sequence and UTR70 from the tobacco mosaic virus (TMV) and spinach, respectively, were also tested. Among the recombinant vectors, pGphyA06 containing the GPD promoter, the ${\Omega}$ sequence, RAmy1A, and GAL7 terminator expressed the highest phytase activity in a culture filtrate, which was estimated at 20 IU/ml. An intracellular localization of the expressed phytase activity in a culture filtrate, which was estimated at 20 IU/ml. An intracellular localization of the expressed phytase was also performed by inserting an endoplasmic reticulum (ER) retention signal, KDEL sequence, into the C-terminus of the phytase within the vector pHphyA-6. It appeared that the KDEL sequence directed most of the early expression of phytase into the intracellular compartment yet more than $60\%$ of the total phytase activity was still retained within the cell even after the prolonged (>3 days) incubation of the transformant. However, the intracellular enzyme activity of the transformant without a KDEL sequence was as high as that of the extracellular one, thereby strongly suggesting that the secretion of phytase in S. cerevisiae appeared to be the rate-limiting step for the expression of a large amount of extracellular recombinant phytase, when compared with other yeasts.

• Reproductive and Developmental Biology
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• 제35권4호
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• pp.427-434
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• 2011

Mitochondria diseases have been reported to involve structural and functional defects of complex I-V. Especially, many of these diseases are known to be related to dysfunction of mitochondrial proton-translocating NADH-ubiquinone oxidoreductase (complex I). The dysfunction of mitochondria complex I is associated with neurodegenerative disorders, such as Parkinson's disease, Huntington's disease, and Leber's hereditary optic neuropathy (LHON). Mammalian mitochondrial proton-translocating NADH-quinone oxidoreductase (complex I) is largest and consists of at least 46 different subunits. In contrast, the NDI1 gene of Saccharomyces cerevisiae is a single subunit rotenone-insensitive NADH-quinone oxidoreductase that is located on the matrix side of the inner mitochondrial membrane. The Saccharomyces cerevisiae NDI1 gene using a recombinant adeno-associated virus vector (rAAV-NDI1) was successfully expressed in AML12 mouse liver hepatocytes and the NDI1-transduced cells were able to grow in media containing rotenone. In contrast, control cells that did not receive the NDI1 gene failed to survive. The expressed Ndi1 enzyme was recognized to be localized in mitochondria by confocal immunofluorescence microscopic analyses and immunoblotting. Using digitonin-permeabilized cells, it was shown that the NADH oxidase activity of the NDI1-transduced cells was not affected by rotenone which is inhibitor of complex I, but was inhibited by antimycin A. Furthermore, these results indicate that Ndi1 can be functionally expressed in the AML12 mouse liver hepatocytes. It is conceivable that the NDI1 gene is powerful tool for gene therapy of mitochondrial diseases caused by complex I deficiency. In the future, we will attempt to functionally express the NDI1 gene in mouse embryonic stem (mES) cell.

• 한국미생물·생명공학회지
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• 제19권3호
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• pp.215-221
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• 1991

YIp5를 사용하여 Cephalosporium acremonium ATCC 2033으로부터 Saccharomyces cerevisiae SHY3에서 발현되는 자율복제 기점 (ARS)를 분리하였다. 자율복제 기점을 갖는 40종의 vector 가운데 가장 안정성 (stability)이 높은 plasmid를 pCY-2라 명명하였으며 pCY-2는 C.acremonium에서 유래하는 3.7kb의 단편을 갖고 있었다. 또 Southern hybridization과 재형질전환을 통해 pCY-2가 효모내에서 자율적으로 복제되고 있다는 것을 확인하였다. 또한 pCY-2는 형질전환율과 안정성에 있어 효모의 ARS를 갖는 YRp7 vector보다 우수하였다.

• KSBB Journal
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• 제11권4호
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• pp.445-452
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• 1996

본 연구에서는 GALl, GALl, GALlO 및 GAP promoter 하류에 reporter 유전자인 K. marxianus의 inulinase 유전자(lNUl)를 연결하여 각각의 재조합 plasmid들을 구축하고, 이들로 형질전환된 S. cerevrswe를 회분배양(YPOG 배지 )하여 외래 유전자 발현에 미치는 promoter의 영향을 비교.검토하 였다. 재조합 효모의 최종 균체농도는 36-39 00600 값을 보여 promoter에 따른 큰 차이를 보이지 않았으나, 포도당 소모기간 동안 비증식속도는 평균 $0.24 h^{-1}$로 유지되다가 galactose 소모기간 동안에 GAL promoter 함유 효모배양의 경우 $0.04-0.06 h^{-1}$, pYIGP 함유 재조합 효모배양은 $0.10 h^{-1}$로 감소하였다. 포도당 고갈 후 inulinase 발현은 시작되었고 균체외 inulinase의 발현 수준은 배양 72시간에 4.3 (GALl promoter), 4.0 (GAL7 promoter), 3.8 (GAL10 promoter) 및 1.6 (GAP promoter) unit/mL에 도달하였다. 평판배지상에서의 활성염색과 회분배양의 결과(최종발현양 및 초기 inulinase 말현속도), inulinase 발현에 미치는 promoter 세기 는 GALl > GALlO > GAL7 > GAP 순임을 알 수 있었다. GAL promoter가 배양말기까지 78 % 이상의 높은 plasmid 안정성을 보인 반면에, GAP promoter의 경우 55%의 낮은 plasmid 안정성을 보였다. 또한, 재조합 inulinase는 promoter 종류에 상관없이 98% 이상 배양액으로 분비되였다.

• Journal of Microbiology and Biotechnology
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• 제22권3호
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• pp.390-399
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• 2012

Endoglucanase gene egIV was cloned from Trichoderma viride AS 3.3711, an important cellulose-producing fungus, by using an RT-PCR protocol. The egIV cDNA is 1,297 bp in length and contains a 1,035 bp open reading frame encoding a 344 amino acid protein with an estimated molecular mass of 35.5 kDa and isoelectronic point (pI) of 5.29. The expression of gene egIV in T. viride AS 3.3711 could be induced by sucrose, corn straw, carboxymethylcellulose (CMC), or microcrystalline cellulose, but especially by CMC. The transcripts of egIV were regulated under these substrates, but the expression level of the egIV gene could be inhibited by glucose and fructose. Three recombinant vectors, pYES2-xegIV, $pYES2M{\alpha}$-egIV, and $pYES2M{\alpha}$-xegIV, were constructed to express the egIV gene in Saccharomyces cerevisiae H158. The CMCase activity of yeast transformants $IpYES2M{\alpha}$-xegIV was higher than that of transformant IpYES2-xegIV or $IpYES2M{\alpha}$-egIV, with the highest activity of 0.13 U/ml at induction for 48 h, illustrating that the modified egIV gene could enhance CMCase activity and that $MF{\alpha}$ signal peptide from S. cerevisiae could regulate exogenous gene expression more effectively in S. cerevisiae. The recombinant EGIV enzyme was stable at pH 3.5 to 7.5 and temperature of $35^{\circ}C$ to $65^{\circ}C$. The optimal reaction condition for EGIV enzyme activity was at the temperature of $55^{\circ}C$, pH of 5.0, 0.75 mM $Ba^{2+}$, and using CMC as substrate. Under these conditions, the highest activity of EGIV enzyme in transformant $IpYES2M{\alpha}$-xegIV was 0.18 U/ml. These properties would provide technical parameters for utilizing cellulose in industrial bioethanol production.