• Journal of Microbiology and Biotechnology
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• v.11 no.4
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• pp.585-591
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• 2001

To compare the p10 promoter activity of Bombyx mori nucleopolyhedrovirus (BmNPV)K1 and K4, recombinant viruses Bm101-LacZ and Bm104-LacZ with a lacZ gene under the control of each p10 promoter were constructed. The $\beta$-galactosidase activity due to Bm101-LacZ was about 5.5- and 1.1-fold higher than that due to Bm104-LacZ and BmK1-LacZ, respectively. expressing ${\beta}$-galactosidase under the control of a polyhedrin promoter. The recombinant virus BmK1-104LacZ with the same genome structure as Bm101-LacZ, except for a p10 promoter region, produced a similar ${\beta}$-galactosidase activity to that due to Bm104-LacZ and 5.5-fold lower than that due to Bm101-LacZ. The virus yield, expression level of polyhedrin, and polyhedra productivity for each recombinant virus was almost similar. These results suggested that the difference in the expression level of ${\beta}$-galactosidase resulted from a difference in the p10 promoter regions, and that an expression vector using the p10 promoter of BmNPV-K1 could be usefully exploited in the mass production of foreign proteins with silkworm larvae by means of oral ingestion.

• Journal of Life Science
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• v.9 no.1
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• pp.50-57
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• 1999

STATs activated by various cytokine and growth factors trigger a quick response in the nucleus and induce changes in gene expression. We have found the sequences homologous to STAT binding site in the 5'-flanking region of the D-raf gene. In this study, we examined role of the STAT binding site in D-raf gene promoter activity in vivo by using transgenic flies. The reporter plasmid pDraf-STATmut-lacZ was constructed by fusing D-raf promoter fragment having the base-substituted STAT binding site with the lacZ gene in a P-element vector. Transgenic flies bearing the Draf-STATmut-lacZ fusion genes were established by P-element mediated transformation. The expression of lacZ in transgenic flies bearing Draf-STATmut-lacZ fusion genes carrying base substitution in STAT site throughout various developmental stages was extensively reduced in comparison with that in transgenic flies bearing wild type Draf-lacZ fusion gene. These results show that the STAT binding site plays an important role in regulation of the D-raf gene.

• KSBB Journal
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• v.10 no.1
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• pp.38-45
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• 1995

The expression of Aspergillus nidulans glyceraldehyde-3-phosphate dehydrogenase (gpdA) and trpC promoters in A. oryzae were compared using E. coli lacZ gents fusions. The specific activities of the expressed E. coli $\beta$-galactosidase in A. oryzae transformants containing the A. nidulans gpdA promoter were around 2,000 units per ug of protein. The specific activities of transformants containing the A. nidulans trpC promoter were very low, ranging from 10.5 to 52.3 units per ug of protein. These results showed that the expression of the A. nidulans gpdA promoter in A. oryzae was approximately 70 times greater than the A. nidulans trpC promoter. In western blot analysis, immunoreactive bands of a imlilar molecular weight as the E. coli $\beta$-galactosidase were observed in A. oryzae carrying the gpdA-lacZ fusion and to a lesser intensity in those carrying the tvpC-lacZ fusion. Southern analysis showed that the higher expression of the gpdA-lacZ fusion as compared to the trpC-lacZ fusion was not due a greater number of integrated plasmids.

• Biomedical Science Letters
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• v.12 no.3
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• pp.139-143
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• 2006

Jopock (Jpk) has previously been ascertained that induces both bacterial and mammalian cell death. The Escherichia coli cells expressing Glutathion S-transferase (GST) fused Jpk showed elongated phenotype and inhibited cell growth which led eventual cell death. In an attempt to search the genetic suppressor of the lethal protein Jpk in bacterial cells, we constructed a unidirectional protein expression vector inserting tac promoter next to the C-terminus Jpk in pGEX-Jpk. The function of additional tac promoter was confirmed by substituting lac promoter in Plac-TOPO plasmid. The cells harboring plac- TOPO, which regulates $lacZ{\alpha}$ gene expression under lac promoter, formed blue colonies in 5-bromo-4-3 $indolyo-{\beta}-D-galactoside$ (X-gal) plate. When lac promoter was changed to tac promoter, same results were observed. Since the addition of tac promoter did not affect the toxic effect of Jpk, the pGEX-Jpk-ptac could be a useful vector for the screening of suppressor(s) for Jpk, in which GST-Jpk and a putative Jpk-suppressing protein are coexpressing from two unidirectional tac promoters, which response to the same inducer, $isopropyl-{\beta}-D-thiogalactopyranoside (IPTG)$.

• Journal of Applied Biological Chemistry
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• v.53 no.1
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• pp.1-7
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• 2010

xylA promoter is a major promoter in xylose operon of Escherichia coli. xylA promoter is sufficient as the promoter for the construction of new expression vector because this promoter was tightly controlled and induced by the addition of xylose. For the construction of xylose-inducible expression vector, 600 bp of xylA promoter was ligated between AatII and HindIII of pUC18, named pXA600. In order to investigate the effect of XylR protein encoded by xylR gene on the xylA promoter, 1,988 bp of xylR gene including its promoter was ligated into downstream of multiple cloning site to the opposite direction of xylA promoter in pXA600, named pXAR600. For the measurement of expression level, 3,048 bp of lacZ structural gene was fused into xylA promoter in both plasmids pXA600 and pXAR600 as a reporter gene, named pXA600-lacZ and pXAR600-lacZ, respectively. The $\beta$-galactosidase activity of pXA600-lacZ and pXAR600-lacZ in E. coli JM109 was determined to be 1,641 and 2,304 unit by the induction with xylose in LB medium, respectively. The $\beta$-galactosidase activity of pXAR600-lacZ/JM109 was about 1.4 times higher by the induction with xylose than that of pXA600-lacZ/JM109. The $\beta$-galactosidase activity of pXA600-lacZ and pXAR600-lacZ in E.coli JM109 showed 6,282 and 9,320 unit by the induction with xylose in DM minimal medium, respectively. A regulator, xylR protein works as an activator for the gene expression by the addition of xylose in the xylose-inducible vectors because the level of gene expression in pXA600 is increased by the insertion of xylR gene into the same vector. The xynA gene of Streptomyces thermocyaneoviolaceus cloned in pXA600 and pXAR600 was successfully expressed in E. coli BLR(DE3). As a result, plasmids pXA600 and pXAR600 using xylA promoter are sufficient as new expression system to produce a foreign protein in E. coli.

• Applied Biological Chemistry
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• v.38 no.1
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• pp.7-12
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• 1995

The purpose of this study was the development of promoter for the lacZ' gene. Two heterologous promoter I and II of lacZ' gene were isolated from chromosomal DNA Bam HI fragment of yeast. The size of the promoter I was estimated to be 2.5 kb and ${\beta}-galactosidase$ activity was 124.6 U/mg protein, and the size of the promoter II was 4.0 kb and its ${\beta}-galactosidase$ activity was 168.8 U/mg protein, respectively. The stability of the recombinant YEp plasmid in the transformant was from 52.7 to 67.4% at minimal medium. YIp plasmid was constructed from YEp plasmid, and expressed both in E. coli and yeast. The promoter I aid II iso-lated from yeast chromosomal DNA can be used for promoter of plasmid YEp and YIp.

• 대한생식의학회:학술대회논문집
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• 2006.06a
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• pp.176.2-176.2
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• 2006

• Journal of Microbiology and Biotechnology
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• v.18 no.2
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• pp.334-337
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• 2008

A tightly regulated gene expression system composed of a single-copy target gene under the control of a lac promoter derivative and lacI gene in a multicopy plasmid is proposed, and its ability to control the flux of a metabolic pathway is demonstrated. A model system to control the flux of acetyl-CoA to acetyl phosphate was constructed by integrating pta, a gene encoding phosphotransacetylase, under a tac promoter into the chromosome of E. coli with a pta-negative background and transforming a multicopy plasmid containing the $lacI^Q$ gene into the strain. The production rate of acetate was shown to be tightly controlled when varying the concentration of the inducer (IPTG) in he model system.

• Asian-Australasian Journal of Animal Sciences
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• v.8 no.5
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• pp.449-454
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• 1995

The present study was conducted to assess gene expression of bacterial lacZ driven by the SV40 promoter at early developmental stages of bovine embryos. The lacZ gene was linearized with BamHI digestion and introduced into the pronucleus by microinjection at 20 hrs after the commencement of in vitro fertilization. Intact bovine blastocysts were not stained with X-Gal, suggesting that there is no endogenous beta-galactosidase activity in these blastocysts. In contrast, the bovine blastocyst cells microinjected with the lacZ gene exerted a characteristic greenish-blue color originating from the bacterial beta-galactosidase activity, albeit at a low rate, i.e. 2.1% of the total fertilized oocytes injected. It was concluded, therefore, that the lacZ gene driven by the SV40 promoter could be used for an indirect screening method in which the presence of transgene is evaluated from the product of transgene expression.

• Journal of Microbiology
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• v.40 no.3
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• pp.205-210
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• 2002

To study interactions between $C_{4}$-dicarboxylic acid transport protein D and E$\sigma$$^{54}$ in the dctA promoter regulatory region, we used the challenge phage system. An ant＇-｀lac fusion was recombined onto the challenge phage, and this ant＇-｀lac fusion along with Pant and the R. meliloti dctA promoter regulatory region were cloned onto a plasmid. The plasmid bearing the ant＇-｀lac fusion was used as a reporter plasmid in a coupled transcription-translation system. Addition of purified $\sigma$$^{54}$ to the coupled system specifically repressed transcription of the plasmid-borne ant＇-｀lac fusion. When DCTD was added along with $\sigma$$^{54}$ to the coupled system, transcription of the ant＇-｀lac fusion was even further repressed, suggesting that DCTD may stabilize closed complexes between E$\sigma$$^{54}$ and the dctA promoter.