• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.355-356
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• 2000

Three 'stress probe' plasmids were constructed and characterized which utilize a green fluorescent protein (CFP) as a non-invasive reporter to elucidate Escherichia coli cellular stress responses in quiescent or 'resting' cells. Facile detection of cellular stress levels was achieved by fusion of three heat shock stress protein promoter elements, those of the heat shock transcription factor ${\sigma}^{32}$, pretense subunit ClpB, and chaperone DnaK, to the reporter gene $gfp_{uv}$. When perturbed by chemical or physical stress (such as heat shock, nutrient (amino acid) limitation, addition of IPTG, acetic acid, ethanol, phenol, antifoam, and salt (osmotic shock), the E. coli cells produced GFPuv which was easily detected from within the cells as emitted green fluorescence. A temporal and amplitudinal mapping of these responses was performed, demonstrating regions where quantitative delineation of cell stress was afforded.

• The Journal of Natural Sciences
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• v.15 no.1
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• pp.89-95
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• 2005

JSRV, which causes sheep lung cancer, is known to have the transforming activity of NIH3T3 cells. Especially Envelope protein of this virus has the transforming activity to NIH3T3. To know the effects on the transcriptional activity of transcription factors by this viral protein transient transfection was performed by using the luciferase reporter system. The result showed that JSRV Envelope protein increased the transcriptional activity of NF-kB and AP-1.

• Animal cells and systems
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• v.6 no.4
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• pp.317-322
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• 2002

To improve conventional yeast one-hybrid screening, we have developed an efficient mammalian one-hybrid system that allows rapid isolation of com-plementary DNAs which are able to induce human p14$^{ARF}$. tumor suppressor gene. A 1.5 kb promoter region of p14$^{ARF}$ was fused to EGFP to generate ARF promoter-EGFP reporter vector. This reporter plasmid was stably trans-fected into NIH3T3 cells for generation of reporter cell line. When the reporter cell line was infected with E2F-1 together with excess amounts of empty vector, the cells that received the positive modulator were readily identifiable by green fluorescence using FACS. The GFP-positive cells were cloned directly from the cultured cells and expanded in bulk culture. The genomic DNAs from GFP-positive cells were prepared and the CDNA insert in integrated retroviral genome was recovered by PCR using primers annealing to the retroviral vector sequences flanking the insert-cloning site. This system should be useful for efficient screening of expression CDNA libraries in mammalian cells to identify novel upstream regulators for spe-cific genes by one-hybrid interaction.ion.

• Journal of Microbiology and Biotechnology
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• v.16 no.9
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• pp.1459-1463
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• 2006

This study explored yeast diauxic promoters using a green fluorescent protein (GFP) reporter to screen growth phase-controlled promoters applicable for foreign protein production. Twenty-five diauxic promoters were inserted into a yeast 2-micron vector in front of the reporter GFP gene. The expressed GFP signal intensity measurements showed that 23 out of the 25 promoters produced a significant fluorescent signal when the cells were in the diauxic growth phase. Among the two strongest promoters pYDL204W and pYLR258W, the former remained constantly active after its activation at the diauxic shift, whereas the latter was only transiently activated right after the deprivation of the medium glucose.

• Nutrition Research and Practice
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• v.2 no.4
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• pp.317-321
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• 2008

Macrophages play a key role in iron metabolism by recycling iron through erythrophagocytosis. Ferroportin-l (FPN1) is a transporter protein that is known to mediate iron export from macrophages. Since divalent metals often interact with iron metabolism, we examined if divalent metals could regulate the expression of FPN1 in macrophages. J774 macrophage cells were treated with copper, manganese, zinc, or cobalt at 10, 50, or $100\;{\mu}M$ for 16 to 24 h. Then, FPN1 mRNA and protein levels were determined by quantitative real-time PCR and Western blot analyses, respectively. In addition, effects of divalent metals on FPN1 promoter activity were examined by luciferase reporter assays. Results showed that copper significantly increased FPN1 mRNA levels in a dose-dependent manner. The copper-induced expression of FPN1 mRNA was associated with a corresponding increase in FPN1 protein levels. Also, copper directly stimulated the activity of FPN1 promoter-driven reporter construct. In contrast, manganese and zinc had no effect on the FPN1 gene expression in J774 cells. Interestingly, cobalt treatment in J774 cells decreased FPN1 protein levels without affecting FPN1 mRNA levels. In conclusion, our study results demonstrate that divalent metals differentially regulate FPN1 expression in macrophages and indicate a potential interaction of divalent metals with the FPN1-mediated iron export in macrophages.

• Molecules and Cells
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• v.23 no.1
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• pp.80-87
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• 2007

Beet curly top virus (BCTV) and Beet severe curly top virus (BSCTV), members of curtoviruses, encode seven open reading frames (ORFs) within a ~3 kb genome. One of these viral ORFs, C1, is known to play an important role in the early stage of viral infection in plants during initiation of viral DNA replication. We used promoter:: reporter (${\beta}$-glucuronidase) gene fusions in transgenic Arabidopsis to identify the putative promoter region of BCTV ORF C1. Unlike other geminiviruses, the intergenic region of BCTV was not sufficient to promote C1 expression in transgenic plants. When sequences extending into the coding region of C1 were tested, strong expression of the reporter protein was observed in vascular tissues of transgenic plants. This expression was not dependent on the presence of the intergenic regions or proximal 5' portions of the C1 coding region. Transgenic plants expressing a reporter gene under control of the putative complete C1 promoter were inoculated with virus to determine if any viral transcript affected C1 expression. Virus inoculated plants did not show any altered pattern or change in of reporter gene expression level. These results suggest that (1) important transcriptional activator elements for C1 expression reside in the 3' portion of C1 coding area itself, (2) C1 protein does not auto-regulate its own expression and (3) C1 expression of two curtoviruses is controlled differently compared to other geminiviruses.

• Parasites, Hosts and Diseases
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• v.53 no.4
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• pp.385-394
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• 2015

Leishmaniasis is a worldwide uncontrolled parasitic disease due to the lack of effective drug and vaccine. To speed up effective drug development, we need powerful methods to rapidly assess drug effectiveness against the intracellular form of Leishmania in high throughput assays. Reporter gene technology has proven to be an excellent tool for drug screening in vitro. The effects of reporter proteins on parasite infectivity should be identified both in vitro and in vivo. In this research, we initially compared the infectivity rate of recombinant Leishmania major expressing stably enhanced green fluorescent protein (EGFP) alone or EGFP-luciferase (EGFP-LUC) with the wild-type strain. Next, we evaluated the sensitivity of these parasites to amphotericin B (AmB) as a standard drug in 2 parasitic phases, promastigote and amastigote. This comparison was made by MTT and nitric oxide (NO) assay and by quantifying the specific signals derived from reporter genes like EGFP intensity and luciferase activity. To study the amastigote form, both B10R and THP-1 macrophage cell lines were infected in the stationary phase and were exposed to AmB at different time points. Our results clearly revealed that the 3 parasite lines had similar in vitro infectivity rates with comparable parasite-induced levels of NO following interferon-${\gamma}$/lipopolysaccharide induction. Based on our results we proposed the more reporter gene, the faster and more sensitive evaluation of the drug efficiency.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2000.04a
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• pp.172-177
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• 2000

• Molecules and Cells
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• v.20 no.2
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• pp.288-296
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• 2005

Cytokines interleukin (IL) 12 and 23 play critical roles in linking innate and adaptive immune responses. They are members of heterodimeric cytokines, sharing a subunit p40. Although IL12/23 p40 is mainly induced in macrophages and dendritic cells (DCs) after stimulation with microbial Toll-like receptor ligands, methods to monitor the cells that produce IL12/23 p40 in vivo are limited. Recently, the mouse model to track p40-expressing cells with fluorescent reporter, yellow fluorescent protein, has been developed. Macrophages and DCs from these mice faithfully reported p40 induction using the fluorescent marker. Here we took advantage of these reporter mice to screen bio-compounds for p40-inducing activity. After screening hundreds of compounds, we found several extracts inducing IL12/23 p40 gene expression. Treatment of DCs with these extracts induced the expression of MHC class II and co-stimulatory molecules, which implies that these might be useful as adjuvants. Next, the in vivo target immune cells of candidate compounds were examined. The reporter system can be useful to identify cells producing IL12 or IL23 in vivo as well as in vitro. Thus, our cytokine reporter system proved to be a valuable reagent for screening for immunostimulatory molecules and identification of target cells in vivo.

• KSBB Journal
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• v.14 no.3
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• pp.377-379
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• 1999

In order to improve the transfection efficiency of CHO/dhfr- cells using cationic lipid, optimal concentrations of the cationic lipid($LipofectAmine^{TM}$) and DNA(pEGFP-C1) need to be determined. The use of green fluorescent protein(GFP) gene as a reporter gene facilitated the quantification of transfection efficiency. The green fluorescence intensity of each cell transfected at various lipid-DNA concentrations was measured using fluorescence-activated cell sorter(FACS) analysis. A combination of $2.0{\mu}L$ cationic lipid and 0.4{$\mu}g$ DNA in a well resulted in the highest trasfection efficiency. Taken together, the method using FACS analysis of GFP is simple and fast, facilitating the optimization of transfection.