• Journal of Microbiology
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• 제35권2호
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• pp.149-151
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• 1997

A plasmid vector with combined features of yeast shuttle vector and mammalian expression vector was constructed to facilitate expression of cloned gene in both cell-types. All necessary elements required for plasmid maintenance and selection in E. coli, yeast and mammalian cells were size-economically arranged in this plasmid. The numan cytomegalovirus (CMV) immediate early promoter and yeast GAL1 promoter were sequentially placed in front of the gene to be expressed. The synthetic splicing donor and acceptor sequences were inserted into the immediate upstream and downstream of the GAL1 promotor, allowing the CMV promotor to direct the expression of a given gene in mammalian cell environment by splicing out the interfering GAL1 promotor sequence. When the resulting vector containing LacZ as a gene was introduced into yeast and mammalian cells, both cells efficiently produced .betha.-galactosidase, dimonstrating its dual host usage.

• 생명과학회지
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• 제16권3호
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• pp.365-368
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• 2006

본 실험에서는 식물의 유용유전자를 개발하여 그 발현양상을 확인하기 위하여 효모를 이용하면 그 발현양상을 비교적 빠르게 확인할 수 있는 미토콘드리아 형질전환 방법을 규명하였다. 또한 미토콘드리아(mt)에 관련된 유전자를 TPI promoter를 가진 plasmid에 재조합한 후 효모에 형질전환하여 mt에서 그 유전자의 특성이 발현 되는 것을 확인하였다. 따라서 본 연구의 결과로 mt에 관련된 유전자를 식물의 조직에 형질전환 하여 1개 이상의 유전자가 식물의 mt에 삽입되어 그 유전자의 특성이 발현되는데 이용되어 질수 있을 것이라 생각된다.

• 한국동물학회:학술대회논문집
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• 한국동물학회 1995년도 한국생물과학협회 학술발표대회
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• pp.82-82
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• 1995

Regulation of enzyme synthesis by transcriptional and translational control systems provides rather stable adaptation to change of amino acid level in the growth medium, while manipulation of enzyme activity through endproduct feedback inhibition represents rather short-term and reversible ways of adjusting metabolic fluctuation of amino acid level. Various control mechanisms interplay to regulate genes encoding enzymes for amino acid biosynthesis in the yeast, Sacchromyces cerevisiae. When amino acids are in short supply, genes under a cross-pathway regulatory mechanism Or general amino acid control (general control) increase their action, in which Gcn4p is the major positive regulator of gene expression. When cells are cultured in minimal medium, basal level expression is also regulated by supplementary control elements, where inorganic phosphate level is additionally involved. Most of amino acid biosynthetic genes are also regulated by the level of endproduct of the pathway. This pathway-specific regulatory mechanism is called specific amino acid control (specific controD, under which gene expression is reduced when endproduct is present in the medium. Derepression of a gene through general control can be usually overridden by repression through specific control, where the endproduct level of that particular pathway is high and not limiting. In this presentation, regulatory factors for basal level expression and general control of yeast amino acid biosynthesis will be discussed, m addition to pathway-specific repression patterns and interaction between CrOSS- and specific-control mechanisms. Preliminary results are also presented from the investigation of the cloned genes in the threonine biosynthetic pathway of the yeast. yeast.

• BMB Reports
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• 제29권4호
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• pp.359-364
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• 1996

By both in vitro hydroxylamine mutagenesis of the wild type 3-phosphoglycerate kinase gene (PGK) promoter DNA and insertion of the leu2-d gene, we have created yeast expression vectors potentially useful for production of eukaryotic genes in yeast. The guanine (G) to adenine (A) change at the -3 position from the ATG start codon of the PGK promoter-based vector rendered a 6~7 times elevated expression of the adjacent eukaryotic gene, and insertion of the leu2-d gene in the vector containing the mutated PGK promoter further enhanced the expression of the gene. When expression of the AIDS virus HIV1-gagP17 gene in a lacZ fusion form was examined with this new vector, a 15 times higher level of expression than that from the original PGK promoter was observed. Northern and Southern analysis showed that this elevated expression is due to the production of a high copy number of mRNA by leu2-d gene functioning and by efficient translation of the produced mRNA. Thus, the vector that contained the A at the -3 position from the ATG start codon in the promoter region and the leu2-d gene shows increased expression capability and will be potentially useful for production of eukaryotic genes in yeast.

• 미생물학회지
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• 제30권2호
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• pp.108-112
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• 1992

To investigate the expression and the secretion of heterologous proteins in yeast, we constructed an yeast secretion vector and produced a human secretory protein, .alpha.-1-antitrypsin (.alpha.-1-AT), from yeast cells. The secretion vector pGAT8 was constructed by inserting the signal sequence of yeast acid phosphatase gene (PH05) into the .alpha.1-AT expression vector pGAT6 which contained .alpha.-1-AT cDNA fused to GAL10-CYC1 promotor. The .alpha.-1-AT was produced efficiently in the yeast cells transformed with plasmid pGAT8, which was onfirmed both by the .alpha.-1-AT activity assay and by the immunoblot method using .alpha.-1-AT antibody. We also showed the secretion of .alpha.-1-AT into the culture media and into the periplasmic space by immunoblot.

• KSBB Journal
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• 제16권1호
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• pp.15-23
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• 2001

The development of expression systems for heterologous proteins has been greatly demanded not only for the study of the structure/function relationships of these proteins but also for their biotechnological and pharmaceutical applications. During the past decades, the methylotrophic yeast Hansenula polymorpha and Pichia pastoris have drawn attention as one of promising hosts for the production of a variety of heterologous proteins. The increasing popularity of H. polymorpha and P. pastoris as the host systems can be attributed to the several advantages over the traditional yeast Saccharomyces cerevisiae, such as the availability of very strong and tightly regulated promoters from the enzymes involved in the metabolism of methanol, a very high-cell density even on simple mineral media, and a high stability of expression plasmids. Furthermore, it has been observed that glycoproteins from these two yeasts are less hyperglycoylated compared to those from S. cerevisiae. Despite substantial similarities as methylotrophic yeasts, however, these two expression systems have some unique features distinguished from each other. In this paper we present a brief overview on the present status of the expression systems developed in methylotrophic yeast, mainly focusing on the similarities and differences between the H. polymorpha and P. pastoris systems.

• Journal of Microbiology and Biotechnology
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• 제8권1호
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• pp.42-48
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• 1998

In order to maximize the secretory expression of human serum albumin (HSA) in the yeast Saccharomyces cerevisiae, a series of HSA expression vectors were constructed with a combination of different promoters, 5' untranslated regions (5'UTR), and secretion signal sequences. The expression vector composed of the galactose-inducible promoter GALl0, the natural 5'UTR, and the natural signal sequence of HSA directed the most efficient expression and secretion of HSA among the constructed vectors when introduced into several S. cerevisiae strains. Although the major form of HSA expressed and secreted in the yeast transformants was the mature form of 66 kDa, the truncated form of 45 kDa was also detected both in the cell extract and in the culture supernatant. The level of the intact HSA protein in the culture supernatant reached up to 30 mg/l at 24 h of cultivation in a shake-flask culture but began to decrease afterwards, indicating that the secreted HSA protein was unstable in a prolonged culture of yeast.

• Journal of Microbiology
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• 제44권6호
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• pp.617-621
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• 2006

Coprinellus congregatus secreted a laccase isozyme when the culture was transferred to an acidic liquid medium (pH 4.1). The laccase cDNA gene (clac2) was used as a probe for cloning of the genomic laccase gene (lac2) including the promoter (Plac2). The open reading frame (ORF) of lac2 had 526 deduced amino acids and four conserved copper binding domains as other fungal laccases. Recombinant plasmid (pRSlac2p-cDNA) of lac2 cDNA with its own promoter was transformed in Saccharomyces cerevisiae. Expression of the transformed lac2 gene was induced by oxidative stress ($H_2O_2$) in yeast and the survival rate of the transformed yeast strain was greatly increased when compared with that of the control strain transformed with pRS316 yeast vector.

• Journal of Applied Biological Chemistry
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• 제43권1호
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• pp.1-4
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• 2000

Chloramphenicol acetyl CoA transferase (CAT) and angiotensin- converting enzyme inhibitory peptide (ACEI) were fused to C-terminal region of rice ubiquitin to examine the level of transcripts or enzyme activities in yeast. When two chimeric genes under an inducible Gall promoter control were transformed into Saccharomyces cerevisaie, both CAT and ACE inhibitory activities were enhanced by three to four-fold as compared to those containing no ubiquitin gene. However, the levels of transcripts of ubiquitin fused and un fused genes were not significantly different each other. Therefore, it was suggested that the expression of foreign genes was post-transcriptionally enhanced by fusion of plant ubiquitin in heterologous organisms such as yeast.

• 미생물학회지
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• 제28권1호
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• pp.1-5
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• 1990

B형 간염바이러스($\alpha$dr 형)의 내면항원(HBcAg) 유전자는 두개의 단백질 합성시작 유전자 암호 ATG를 갖는다. 하나는 전위내 면항원을 다른 하나는 내면항원 유전자들 위한 ATG 부호이다. 내연항원의 발현과 전위내면항원의 역할을 연구한기 위하여 전위내면 항왼 유전자를 포함하는 것과 포함하지 않는 내연항원 유전자를 효모발현 운반체에 클j료녕 하였다. 또한 내면항원의 발현에 5 upstream 의 역할을 알아보기 위하여 여러 가지의 5’ 제거툴연변이체를 클로닝하였다. 앞에서 만들어진 플라스미드로 여러 효모 균주을 형질전환시킨 후 발헨된 내면항원과 그와 관련된 항원 HBeAg을 방사면역측정법 으로 확인하였다. 효모에서 내면항원 발현의 최적조건 허에서 가장 높은 수준의 항원은 PGK promoter 와 terminator에 내연향원 올 포함한 pGKHBc를 가진 SHY4에서 검출되었다. 전위내면부위의 존재와 우관하게 내면항원은 배양액에서는 검출되지 않고 세포내에서만 검출되었다. 이 결과는 전위내면항원이 효모 내에서 내연항왼의 분비에 영향올 주지않음을 의미한다.