• 한국미생물·생명공학회지
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• 제33권4호
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• pp.241-247
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• 2005

선별마커로써 Lactococcus lactis ssp. lactis ATCC 7962 유래의 $\beta$-galactosidase 유전자를 포함하는 Lactococcus용 셔틀/발현 벡터 pWgall3T를 제조하여 Escherichia coli DH5$\alpha$와 고. Lactis MG1363내로 도입하였다. 이들 형질 전환체들은 X-gal을 포함하는 배지에서 파란색의 표현형을 보임으로써 쉽게 확인할 수 있었다. 또한, L. lactis MG1363 형질전환체로부터 $\beta$-galactosidase 활성을 측정한 결과 기존에 $\beta$-galactosidase를 활성을 지닌 L. lactis ATCC 7962에 비해 glucose를 포함하는 M17배지에서 4배정도 높은 활성을 보임으로써 선별마커로써의 효율성을 나타내었다. pWgal13T는 $\beta$-galactosidase 유전자 외에 L. lactis Wg2유래의 replicon과 외래 유전자의 발현을 위한 L. lactis ssp. cremoris LM0230의 promoter P13C, terminator를 포함하고 있다. 이 벡터의 이용가능성을 확인하기 위하여 외래 유전자 EGFP유전자를 P13C 아래에 삽입하여 E. coli와 L. iactis에서 발현을 확인하였다. 이 연구에서 제조된 Lactococcus용 발현 벡터 pWgal13T는 E. coli와 L. lactis에서 외래 유용 유전자를 생산을 위해 이용 할 수 있을 것이다.

• 농업과학연구
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• 제23권1호
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• pp.80-89
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• 1996

본 연구에서는 인간에게 유용한 여러 생리적 기능을 갖는 Human lactoferrin (hLf)을 대량생산할 목적으로 동물 세포의 단백질을 안정하게 생산 및 분비할 수 있는 진핵생물인 효모 sacduraromyces diastaticus YIY345에 hLf 유전자를 도입하여 hLf의 발현 및 분비를 시도하였다. 1. hLf의 발현 및 분비를 위하여 STA1 (S. diasticus glucoamylase) 유전자의 promoter 및 분비 신호와 hLf 전사 종결을 위한 GAL7(galactose utilizing gene) transcriptional terminator하에 재조합 plasmid pYEGLf를 제작하였다. 2. 제작한 plasmid를 선별하고 증폭하기 위하여 대장균에 형질 전환하였고 대장균 형질전환체로부터 plasmid를 분리하여 적당한 제한 효소로 처리하고 크기를 확인하였다. 최종적으로 선별된 plasmid는 효모 S. diastaticus YIY345에 형질 전환시켜 효모 형질전환체를 얻었다. 3. 효모 형질전환체를 Western hybridization으로 단백질 수준에서 분석한 결과 pYEGLf가 도입된 형질전환체에서 hLf가 생산되어 세포외로 분비되었다. 4. hLf가 발현된 효모 형질전환체의 배양상등액을 paper disc법을 이용하여 E.coli에 대한 항균 효과를 측정하였으나 관찰할 수 없었다. E.coli에 대한 hLf의 MIC (minimal inhibitory concentration)는 약 $3000{\mu}g/m{\ell}$에 비해 효모에서 분비하는 hLf의 양은 상당히 적으므로 항균효과를 측정하기 불가능하다. 그러므로 정제 단계를 거쳐 더 높은 농도로 처리해야 할 것이다.

• 생명과학회지
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• 제22권12호
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• pp.1600-1607
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• 2012

Matrix metalloproteinase (MMP)는 세포외골격의 주요 조절효소로, 배아발생, 혈관생성, 상처치료 및 조직 재생과정에 중요한 인자로 알려져 있다. MMP의 조절 이상은 비정상적 세포외골격 분해로 인해 암 전이와 같은 질병을 일으킨다. 따라서, MMP의 발현과 활성은 엄격하게 조절되고 있다. 최근, 초파리 Mmp1이 소화기관에서 강하게 발현되며, 장줄기세포의 비정상적인 활성을 억제하여 장의 항상성 유지에 중요함을 밝혔다. 하지만, 장조직에서 Mmp1의 발현 조절 기전은 아직 밝혀지지 않았다. 본 연구에서는, 장조직에서 Mmp1의 발현이 장 발생과 항상성 유지에 중요한 Caudal homeobox 유전자에 의해 조절되는지를 연구하였다. GAL4/UAS 조절계를 이용하여 장조직 특이적으로 Caudal의 발현을 감소시켰을 때, Mmp1의 발현이 감소함을 확인하였으며, Caudal을 과발현 시켰을 때, Mmp1의 발현이 증가함을 in vitro와 in vivo 실험 모두에서 확인하였다. 또한, Mmp1 promoter에 Caudal 전사인자 결합 부위가 존재하며, 이 부위가 Mmp1 발현에 중요한 역할을 함을 확인하였다. 이상의 본 연구는, 정상적 혹은 암화 과정에서 Mmp1이 Caudal의 표적 유전자일 수 있음을 의미한다.

• 대한수의학회지
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• 제35권1호
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• pp.95-105
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• 1995

The human homolog of position specific element of mouse Hoxa-7 was studied using transgene. It contains a 1.1 kb human DNA (HCR)- a homolog to the intergenic region between Hoxa-7 and -9, which directs the position specific expression of Hoxa-7-, tk promoter, LacZ (${\beta}$-galactosidase) gene as a reporter, and polyadenylation signal of SV40 large T antigen. It was injected into the mice embryos, and the resulting transgenic embryos were analysed through PCR as well as genomic Southern blotting with placenta DNA. Out of 20 embryos analysed, two were transgenic. Among them, one transgenic embryo expressed transgene when stained with X-gal. The expression pattern was in analogy to that of the mouse Hoxa-7, showing spatially restricted expression pattern, Since the expression of ${\beta}$-galactosidase is regulated by the upstream human HCR sequence, it implies that the HCR is the plausible position specific regulatory element of human.

• 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.

• Journal of Microbiology and Biotechnology
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• 제16권11호
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• pp.1799-1808
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• 2006

A food-grade integration vector based on site-specific recombination was constructed. The 5.7-kb vector, pIMA20, contained an integrase gene and a phage attachment site originating from bacteriophage A2, with the ${\alpha}$-galactosidase gene from Lactobacillus plantarum KCTC 3104 as a selection marker. pIMA20 was also equipped with a controllable promoter of nisA ($P_{nisA}$) and a signal peptide-encoding sequence of usp45 ($SP_{usp45}$) for the production and secretion of foreign proteins. pIMA20 and its derivatives mediated site-specific integration into the attB-like site on the Lactococcus lactis NZ9800 chromosome. The vector-integrated recombinant lactococci were easily detected by the appearance of blue colonies on a medium containing $X-{\alpha}-gal$ and also by their ability to grow on a medium containing melibiose as the sole carbon source. Recombinant lactococci maintained these traits in the absence of selection pressure during 100 generations. The ${\alpha}-amylase$ gene from Bacillus licheniformis, lacking a signal peptide-encoding. sequence, was inserted downstream of $P_{nisA}\;and\;SP_{usp45}$ in pIMA20, and the plasmid was integrated into the L. lactis chromosome. ${\alpha}-Amylase$ was successfully produced and secreted by the recombinant L. lactis, controlled by the addition and concentration of nisin.

• Journal of Microbiology and Biotechnology
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• 제22권12호
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• pp.1644-1652
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• 2012

Iron plays a key role in host-pathogen interactions. Microbial pathogens require iron for survival and virulence, whereas mammalian hosts sequester and withhold iron as a means of nutritional immunity. We previously identified two paralogous genes, CFT1 and CFT2, which encode homologs of a fungal iron permease, Cft1 and Cft2, respectively, in the human fungal pathogen Cryptococcus neoformans. Cft1 was shown to play a role in the high-affinity reductive iron uptake system, and was required for transferrin utilization and full virulence in mammalian hosts. However, no role of Cft2 has been suggested yet. Here, we identified the third gene, CFT3, that produces an additional fungal iron permease homolog in C. neoformans, and we also generated the cft3 mutant for functional characterization. We aimed to reveal distinct functions of Cft1, Cft2 and Cft3 by analyzing phenotypes of the mutants lacking CFT1, CFT2 and CFT3, respectively. The endogenous promoter of CFT1, CFT2 and CFT3 was replaced with the inducible GAL7 promoter in the wild-type strain or in the cft1 mutant for gain-of-function analysis. Using these strains, we were able to find that CFT2 is required for growth in low-iron conditions in the absence of CFT1 and that overexpression of CFT2 compensates for deficiency of the cft1 mutant in iron uptake and various cellular stress conditions. However, unlike CFT2, no clear phenotypic characteristic of the cft3 mutant and the strain overexpressing CFT3 was observed. Overall, our data suggested a redundant role of Cft2 in the high-affinity iron uptake and stress responses in C. neoformans.

• BMB Reports
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• 제49권12호
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• pp.693-698
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• 2016

In this study, a tissue-specific GAL4/UAS activation tagging system was used for the characterization of genes which could induce lethality when ubiquitously expressed. A dominant mutant exhibiting stunted growth was isolated and named defective root development 1-D (drd1-D). The T-DNA tag was located within the promoter region of AtTX12, which is predicted to encode a truncated nucleotide-binding leucine-rich repeat (NLR) protein, containing a Toll/interleukin-1 receptor (TIR) domain. The transcript levels of AtTX12 and defense-related genes were elevated in drd1-D, and the misexpression of AtTX12 recapitulated the drd1-D phenotypes. In the presence of ENHANCED DISEASE SUSCEPTIBILITY 1 (EDS1), a key transducer of signals triggered by TIR-type NLRs, a low-level of AtTX12 misexpression induced strong defective phenotypes including seedling lethality whereas, in the absence of EDS1, a high-level of AtTX12 misexpression induced weak growth defects like dwarfism, suggesting that AtTX12 might function mainly in an EDS1-dependent and partially in an EDS1-independent manner.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVI)
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• pp.402-406
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• 2005

Lipomyces starkeyi produces a novel glucanhydrolase containing endo-dextranase and ${\alpha}-amylase$ activities. A cDNA from L. starkeyi encoding a dextranase was isolated and characterized. The 2,052 kb cDNA fragment (lsd1) carrying dextranase gene showed one open reading frame (ORF) composed of 1,824 bp flanked by a 41 bp 5'-UTR and a 184 bp 3'-UTR including a poly(A) tail of 27 bp. The ORF encodes for a 608 amino acid with a predicted molecular mass of 67.6 kDa. There was 77% deduced amino acid sequence identity between the LSD1 dextranase and the dextranase from Penicillium minioluteum. The primary structure of the dextranase from L. starkeyi has distant similarity with enzymes belonging to glycosyl hydrolase family 49. The lsd1 protein was expressed in the Saccharmyces cerevisiae under control of GAL1 promoter and active dextranase was produced.

• 한국미생물·생명공학회지
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• 제24권3호
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• pp.290-298
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• 1996

In an effort to understand the role of the conserved domain and of the heterologous one-third part of the carboxy terminal domain of transglutaminase C (TGase II), attempts were made to express TGase II cDNA of human origin in yeast Saccharomyces cerevisiae as in a full-length form as well as in a form of C-terminal truncation. The 2$\mu$-based expression plasmids which contained the TGase II cDNA under the gal inducible promoter were introduced into yeast and the maintenance of the full-length and truncated form of the TGase II gene plasmids were confirmed by Southern blot. The expression of the TGase II gene was analysed by reverse transcription polymerase chain reaction (RT-PCR), and western blot analyses. As assayed by [1,4$^{14}$C]-putrescine incorporation into succinylated casein, the full-lenth as well as the truncated forms of recombinant TGase II showed some catalytic activity. These results indicate that the N-terminal homologous domain of human TGase II retains a catalytically active domain. The level of TGase II expressed in yeast, however, was far lower than satisfactory and other expression system should be sought further chracterization of the enzyme. The negative effect of TGase II on the growth of yeast is interesting with respect to the physiological effect of TGase II in cornification of epidermal keratinocytes.