• Journal of Plant Biology
• /
• v.38 no.1
• /
• pp.19-24
• /
• 1995

The vir genes expression of Ti plasmid is induced by a family of related phenolic compounds. We investigated the effects of various phenolic compounds, Ti plasmids and hosts on the expression of the vir genes in the same type of octopine Ti plasmids, pTiKU12, pTiAch5 and pTiA6. The vir gene induction of pTiKU12 was remarkably stimulated by p-coumaric acid in relation to acetosyringone, but those of pTiAch5 and pTiA6 were more stimulated by acetosyringone than by p-coumaric acid. The effect of phenolic compound on the vir gene induction was different according to the kind of Ti plasmids. Also, the vir gene expression of A. tumefaciens KU913, which has pTiKU12 was about 6.2 times as much as that of A. tumefaciens KU915, which has pTiKU12 in KU12 host, in the presence of ferulic acid. But no difference was shown in the presence of p-coumaric acid. The vir gene induction abilities of phenolic compounds are different according to the kinds of phenolic compounds, Ti plasmids and hosts.

• KSBB Journal
• /
• v.5 no.1
• /
• pp.49-58
• /
• 1990

We constructed hybrid plasmids to allow controlled and extracellular production of human alpha-interferon in Escherichia coli. The hybrid plassmids were constructed by transferring alpha-lFN gene from plasmid Hif-2h which has the alpha-lFN gene at PstI restriction site of pBR322, to plasmids pIN -IIIB3 and pIN-IIIC3 at restriction sites between HindIII and BamHI. Plasmids pIN-IIIB3 and pIN-IIIC3 carry E. coli lipoprotein promoter, lac promoter and operator in tandem. The plasmids also have lacl genes which encode for lac repressors, which allows controlled expression of genes cloned to the plasmids by using of inducer IPTG. Lipoprotein signal sequence is located just ahead of cloning sites of the plasmids, which helps cells to excrete or secrete cloned gene products. Plasmid pUC9 was used as a intermediate vector for transferring of alpha-lFN gene from Hif-2h to pIN vectors in order to solve the problem of different restriction sites between Hif-2h and pIN vectors.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.15 no.4
• /
• pp.1000-1006
• /
• 2011

We examined the effects of various phenolic compounds, Ti plasmids(octopine, nopaline) and A. tumefaciens on the vir gene expression. Nine phenolic compounds were tested using 3 types of Ti plasmid and 3 strains of A. tumefaciens on the vir gene expression. It was also investigated how the levels of vir gene expression could be related to specific phenolic compounds. Six phenolic compounds as 4-hydroxyacetophenone, phenol, catechol, resorcinol, acetosyringone and vanillin had exhibited a strong effect on the vir gene expression of A. tumefaciens MW107 containing nopaline Ti plasmid. The vir genes of A. tumefaciens MW105 and MW108 containing octopine Ti plasmids were remarkably stimulated only by acetosyringone. Thus, it appeared that the vir gene inducing abilities were differed by the kinds of phenolic compounds, A. tumefaciens and Ti plasmids.

• Asian Pacific Journal of Cancer Prevention
• /
• v.14 no.2
• /
• pp.1067-1072
• /
• 2013

Hiwi, a human homologue of the Piwi family, plays an important role in stem cell self-renewal and is overexpressed in various human tumors. This study aimed to determine whether an RNA interference-based strategy to suppress Hiwi expression could inhibit tumor growth in a xenograft mouse model. A rare population of $SSC^{lo}\;Alde^{br}$ cells was isolated and identified as lung cancer stem cells in our previous study. Plasmids containing U6 promoter-driven shRNAs against Hiwi or control plasmids were successfully established. The xenograft tumor model was generated by subcutaneously inoculating with lung cancer stem cell $SSC^{lo}\;Alde^{br}$ cells. After the tumor size reached about 8 mm in diameter, shRNA plasmids were injected into the mice via the tail vein three times a week for two weeks, then xenograft tumor growth was assessed. In nude mice, intravenously delivery of Hiwi shRNA plasmids significantly inhibited tumor growth compared to treatment with control scrambled shRNA plasmids or the vehicle PBS. No mice died during the experiment and no adverse events were observed in mice administered the plasmids. Moreover, delivery of Hiwi shRNA plasmids resulted in a significant suppressed expression of Hiwi and ALDH-1 in xenograft tumor samples, based on immunohistochemical analysis. Thus, shRNA-mediated Hiwi gene silencing in lung cancer stem cells by an effective in vivo gene delivery strategy appeared to be an effective therapeutic approach for lung cancer, and may provide some useful clues for RNAi gene therapy in solid cancers.

• Korean Journal of Microbiology
• /
• v.27 no.2
• /
• pp.85-91
• /
• 1989

The effect of SV40 and murine cytomegalovirus (MCMV) enhancers on the general and tissue-specific gene expression was investigated. Recombinant plasmids containing these transcriptional engancers downstream of a structural gene for chloramphenicol acetyl transferase (CAT) were constructed. The transient expression of CAT gene from these plasmids was measured in monkey (CV1PD) and HeLa cells. Both SV40 and MCMV engancers activated the expression of CAT gene by more than 20 and 150 folds, respectively, compared with engancerless plasmids. When the SV40 promoter, upstream of CAT gene, was replaced with 2.2 kbp of promoter regulatory region of bovine growth hormone (bGH) gene, there was no expression of CAT even in the presence of enhancers, reflecting the tissue-specific expression of bGH genes. However, when the bGH regulatory region was shortened to 230 bp, the expression level increased dramatically in the presence of SV40 enhancers. In contrast, the expression from the shortened promoter was only marginally activated by the stronger MCMV enhancer.

• BMB Reports
• /
• v.31 no.5
• /
• pp.503-507
• /
• 1998

To investigate the effects of the Vitreoscilla hemoglobin (VHb) gene on the production of a heterologous protein, a comparative expression system for VHb and ferritin was constructed. First, the VHb gene was inserted into the downstream and upstream regions of the ferritin gene to construct pHF2 and pHF3, respectively. Next, the two plasmids pACHB1 and pVUTFH10, having the VHb gene and the ferritin gene respectively, were constructed in order to express the two genes in different plasmids by using a coplasmid expression system. It was observed that the cell growth was improved in all strains containing the VHb gene. Furthermore, in our coplasmid expression system, the presence of the VHb gene increased production of the ferritin by 1.8 times, as much as that in a strain not having the VHb gene.

• Microbiology and Biotechnology Letters
• /
• v.20 no.6
• /
• pp.637-641
• /
• 1992

The promoter regions from chromosomal DNA of Bacillus sp. SSA3 which is responsible for fermentation of Korean traditional soy sauce, were cloned for construction of expression vector of Bacills sp. SSA3. Recombinant plasmids were constructed by insertion of HindIIl-cleaved Bacillus sp. SSA3 chromosomal DNA fragments in front of the CAT gene of pGR71 plasmid and B-galactosidase gene of pUC18 plasmid. 6 recombinant plasmids were isolated from chloramphenicol resistant E. coli JM109 clones. All these plasmids were found to have promoter activity in Bacills sp. SSA3 and E. coli JM109. When these 6 clones of Bacills sp. SSA3 were cultivated in LB agar medium supplemented with 10% NaCI. fused CAT gene expression of 4 clones was significantly decreased in common. But the others were poorly inhibited.

• Applied Biological Chemistry
• /
• v.35 no.4
• /
• pp.227-231
• /
• 1992

The plasmids pSUPBT and pSUPBTR were constructed with a vector pSUP2021 and the BT toxin gene in the plasmid pES 1. The plasmids constructed were introduced into the antagonistic rhizobacteria P. fluorescens KR164 by conjugation and P. fluorescens having pSUPBT and pSUPBTR were named P. fluorescens KR164(pSUPBT)#2, KR164(pSUPBT)#3, KR164(pSUPBTR)#2 and KR164(pSUPBTR)#3, respectively. The BT toxin gene were identified in all transformants by Southern hybridization and the final product of BT toxin gene was identified only in P. fluorescens KR164(pSUPBTR)#3 by SDS-PAGE. This crystal toxin protein were also observed in electron microscopy.

• Microbiology and Biotechnology Letters
• /
• v.19 no.6
• /
• pp.575-582
• /
• 1991

To increase the production of glutathione by the expression of recombinant gsh plasmids, two genes responsible for the biosynthesis of glutathione were isolated and cloned. To clone a gshI gene, the GS903 mutant strain, which is deficient in $\gamma$-glutamylcysteine synthetase activity, has been raised. A gshI gene was cloned using pBR322 plasmid as a 3.6 Kb PstI DNA fragment isolated from E. coli K-12 chromosomal DNA. Also a gshIl gene was cloned using pUC13 plasmid as a 2.2 Kb PstI-BamHI DNA fragment. To study the effects of plasmid copy number and passenger DNA size on the expression levels of the gsh genes, various recombinant plasmids containing different sets of genes were constructed. The expression levels of the gsh genes were increased approximately twice higher in pUC series plasmids than that in pBR322 plasmid. But the sizes of the passenger DNA containing the gsh genes in the vector plasmid did not affect on the expression levels of the gsh genes.

• KSBB Journal
• /
• v.11 no.4
• /
• pp.504-509
• /
• 1996

Promoters which are useful for constructing expression vectors for lactic acid bacteria were obtained from the chromosomal DNA of Lactococcus lactis ssp. lactis MG1363. pBV5030, a promoter-selection vector, replicates in L. lactis and Escherichia coli and carries a promoterless chloramphenicol acetyltransferase gene (cat-86). After examining E. coli transformants which grew on LB media containing chloramphenicol (Cm, 20$\mu\textrm{g}$/mL) , many MG1363 derived DNA fragments which encompass promoter sequences were identified. Some recombinant E. coli cells can grow at the Cm concentration of 1,000$\mu\textrm{g}$/mL. When plasmids from those highly resistant E. coli cells were purified and introduced into L. lactis ssp. lactis MG1614 cells by electroporation, lactococcal transformants showing Cm resistance were obtained. So far, five plasmids with different promoter inserts were introduced into L. lactis MGl614 cells. The maximum level of Cm resistance in L. lactis MG1614 transformants was quite low (20$\mu\textrm{g}$/mL) when compared with that observed in recombinant E. coli cells harboring the same plasmids.