• Title/Summary/Keyword: Utility promoter

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Functional Evaluation of the Rockbream (Oplegnathus fasciatus) Beta-actin Promoter as a Candidate Regulatory Element for DNA Vaccination

  • Kosuke, Zenke;Lee, Sang-Yoon;Kim, Ki-Hong;Nam, Yoon-Kwon
    • Fisheries and Aquatic Sciences
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    • v.12 no.2
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    • pp.98-103
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    • 2009
  • The potential utility of the rockbream (Oplegnathus fasciatus) $\beta$-actin 5'-upstream sequence as a regulatory element for DNA vaccination was evaluated based on in vitro and in vivo heterologous expression assays. In the in vitro transfection experiment, the efficacy of the rockbream $\beta$-actin promoter to drive the expression of a downstream lacZ gene was significantly higher (more than fourfold) than that of the human cytomegalovirus (hCMV) promoter in two fish cell lines (grunt Haemulon plumierii fin and bluegill Lepomis macrochirus fry cell lines). In contrast, the functional activity of the rockbream $\beta$-actin promoter was hardly detectable in a mammalian mouse embryonic fibroblast cell line. Rockbream skeletal muscles injected in vivo with a GFP reporter construct driven by the $\beta$-actin promoter displayed the significantly higher expression of a GFP protein (more than threefold) than did those injected with hCMV promoter driven construct. Data from this study suggest that the homologous rockbream $\beta$-actin promoter could be used as a potential regulator for DNA vaccination in this species.

Biotechnological improvement of lignocellulosic feedstock for enhanced biofuel productivity and processing

  • Ko, Jae-Heung;Kim, Hyun-Tae;Han, Kyung-Hwan
    • Plant Biotechnology Reports
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    • v.5 no.1
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    • pp.1-7
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    • 2011
  • Secondary walls have recently drawn research interest as a primary source of sugars for liquid biofuel production. Secondary walls are composed of a complex mixture of the structural polymers cellulose, hemicellulose, and lignin. A matrix of hemicellulose and lignin surrounds the cellulose component of the plant's cell wall in order to protect the cell from enzymatic attacks. Such resistance, along with the variability seen in the proportions of the major components of the mixture, presents process design and operating challenges to the bioconversion of lignocellulosic biomass to fuel. Expanding bioenergy production to the commercial scale will require a significant improvement in the growth of feedstock as well as in its quality. Plant biotechnology offers an efficient means to create "targeted" changes in the chemical and physical properties of the resulting biomass through pathway-specific manipulation of metabolisms. The successful use of the genetic engineering approach largely depends on the development of two enabling tools: (1) the discovery of regulatory genes involved in key pathways that determine the quantity and quality of the biomass, and (2) utility promoters that can drive the expression of the introduced genes in a highly controlled manner spatially and/or temporally. In this review, we summarize the current understanding of the transcriptional regulatory network that controls secondary wall biosynthesis and discuss experimental approaches to developing-xylem-specific utility promoters.

Bacterial Hash Function Using DNA-Based XOR Logic Reveals Unexpected Behavior of the LuxR Promoter

  • Pearson, Brianna;Lau, Kin H.;Allen, Alicia;Barron, James;Cool, Robert;Davis, Kelly;DeLoache, Will;Feeney, Erin;Gordon, Andrew;Igo, John;Lewis, Aaron;Muscalino, Kristi;Parra, Madeline;Penumetcha, Pallavi;Rinker, Victoria G.;Roland, Karlesha;Zhu, Xiao;Poet, Jeffrey L.;Eckdahl, Todd T.;Heyer, Laurie J.;Campbell, A. Malcolm
    • Interdisciplinary Bio Central
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    • v.3 no.3
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    • pp.10.1-10.8
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    • 2011
  • Introduction: Hash functions are computer algorithms that protect information and secure transactions. In response to the NIST's "International Call for Hash Function", we developed a biological hash function using the computing capabilities of bacteria. We designed a DNA-based XOR logic gate that allows bacterial colonies arranged in a series on an agar plate to perform hash function calculations. Results and Discussion: In order to provide each colony with adequate time to process inputs and perform XOR logic, we designed and successfully demonstrated a system for time-delayed bacterial growth. Our system is based on the diffusion of ${\ss}$-lactamase, resulting in destruction of ampicillin. Our DNA-based XOR logic gate design is based on the op-position of two promoters. Our results showed that $P_{lux}$ and $P_{OmpC}$ functioned as expected individually, but $P_{lux}$ did not behave as expected in the XOR construct. Our data showed that, contrary to literature reports, the $P_{lux}$ promoter is bidirectional. In the absence of the 3OC6 inducer, the LuxR activator can bind to the $P_{lux}$ promoter and induce backwards transcription. Conclusion and Prospects: Our system of time delayed bacterial growth allows for the successive processing of a bacterial hash function, and is expected to have utility in other synthetic biology applications. While testing our DNA-based XOR logic gate, we uncovered a novel function of $P_{lux}$. In the absence of autoinducer 3OC6, LuxR binds to $P_{lux}$ and activates backwards transcription. This result advances basic research and has important implications for the widespread use of the $P_{lux}$ promoter.

A Series of IncQ-Based Reporter Plasmids for Use in a Range of Gram-Negative Genera

  • O'Sullivan, Laura E.;Nickerson, Cheryl A.;Wilson, James W.
    • Journal of Microbiology and Biotechnology
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    • v.20 no.5
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    • pp.871-874
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    • 2010
  • Many studies require expression analysis of the same gene/promoter across a range of bacterial genera. However, there is currently a lack of availability of reporters based on the broad-host-range IncQ replicon, which is compatible with a popular improved IncP transfer system that is self-transfer defective. We report IncQ lacZ reporter plasmids with features including (1) compatibility with IncP, IncW, and pBHR/pBBR replicons, (2) a variety of antibiotic markers (Sp-r, Sm-r, Km-r, Cm-r), (3) convenient mobilization via a novel self-transfer-defective IncP conjugation system, and (4) GenBank DNA sequences. Utility is demonstrated using three different promoters in different Gram-negative genera.

Prognostic role of EGR1 in breast cancer: a systematic review

  • Saha, Subbroto Kumar;Islam, S.M. Riazul;Saha, Tripti;Nishat, Afsana;Biswas, Polash Kumar;Gil, Minchan;Nkenyereye, Lewis;El-Sappagh, Shaker;Islam, Md. Saiful;Cho, Ssang-Goo
    • BMB Reports
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    • v.54 no.10
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    • pp.497-504
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    • 2021
  • EGR1 (early growth response 1) is dysregulated in many cancers and exhibits both tumor suppressor and promoter activities, making it an appealing target for cancer therapy. Here, we used a systematic multi-omics analysis to review the expression of EGR1 and its role in regulating clinical outcomes in breast cancer (BC). EGR1 expression, its promoter methylation, and protein expression pattern were assessed using various publicly available tools. COSMIC-based somatic mutations and cBioPortal-based copy number alterations were analyzed, and the prognostic roles of EGR1 in BC were determined using Prognoscan and Kaplan-Meier Plotter. We also used bc-GenEx-Miner to investigate the EGR1 co-expression profile. EGR1 was more often downregulated in BC tissues than in normal breast tissue, and its knockdown was positively correlated with poor survival. Low EGR1 expression levels were also associated with increased risk of ER+, PR+, and HER2- BCs. High positive correlations were observed among EGR1, DUSP1, FOS, FOSB, CYR61, and JUN mRNA expression in BC tissue. This systematic review suggested that EGR1 expression may serve as a prognostic marker for BC patients and that clinicopathological parameters influence its prognostic utility. In addition to EGR1, DUSP1, FOS, FOSB, CYR61, and JUN can jointly be considered prognostic indicators for BC.

Preparation of Diphtheria Toxin A Chain from Escherichia coli

  • Lee, Jong-Soo;Yoon, Kyoung-Bum;Park, Jong-Won;Choi, Suk-Jung
    • BMB Reports
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    • v.30 no.2
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    • pp.144-149
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    • 1997
  • An expression vector was constructed containing the gene encoding diphtheria toxin A (DTA) which was placed after a T7 promoter. Cytoplasmic expression of the DTA gene resulted in the formation of an insoluble inclusion body. The inclusion body was collected after the complete lysis of the cell, and subsequent washing with 0.1% Triton X-100 released 16~30% of DTA protein from the inclusion body along with other contaminating proteins. The released DTA protein was purified by dialysis. The remaining pellet was dissolved in 8 M urea containing 5% ${\beta}-mercaptoethanol$, and the denatured DTA was renatured by the dilution-dialysis method. The total yield was 35%, and about 5 mg DTA was obtained from 1 L culture. The DTA protein has a free sulfhydryl group exposed to the protein surface, and was shown to have a tendency to dimerize through disulfide formation in the absence of ${\beta}-mercaptoethanol$. The utility of the sulfhydryl group was tested for the construction of recombinant toxins.

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Expression Patterns of the chgH:rfp Transgene in Response to 17α-Ethinylestradiol (EE2) Exposure in Marine Medaka Oryzias dancena

  • Nam, Yoon Kwon;Cho, Young Sun;Kim, Dong Soo
    • Fisheries and Aquatic Sciences
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    • v.18 no.1
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    • pp.65-71
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    • 2015
  • The functional utility of a transgenic marine medaka Oryzias dancena strain carrying the red fluorescent protein (RFP) gene driven by an endogenous choriogenin H (chgH) promoter was evaluated for its ability to detect waterborne $17{\alpha}$-ethinylestradiol (EE2), a synthetic estrogen derivative. The chgH:rfp transgenic marine medaka larvae showed an age-dependent tendency in the efficiency of EE2-mediated transgene expression, in which transgenic larvae older than 6 days post-hatching displayed a more effective response in their transgene expression to EE2 than did younger hatchlings. During experimental exposures to high concentrations of EE2 (200 to 1,000 ng/L), the transgenic responses in the hatchlings were broadly dose- and duration-dependent. With exposures using lower doses of EE2 (25, 50 and 100 ng/L), EE2-induced transgenic RFP was also observed in the transgenic larvae, although the lower doses required exposure of longer duration. Under the EE2 exposure and microscope assay conditions used in our study, transgenic marine medaka larvae exhibited a similar degree of EE2-mediated RFP phenotype expression at various salinity levels (0, 15 and 30 ppt).

A Cyan Fluorescent Protein Gene (cfp)-Transgenic Marine Medaka Oryzias dancena with Potential Ornamental Applications

  • Vu, Nguyen Thanh;Cho, Young Sun;Lee, Sang Yoon;Kim, Dong Soo;Nam, Yoon Kwon
    • Fisheries and Aquatic Sciences
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    • v.17 no.4
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    • pp.479-486
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    • 2014
  • To evaluate their potential utility as an ornamental organism, novel transgenic marine medaka Oryzias dancena strains with a highly vivid fluorescent phenotype were established through transgenesis of a cyan fluorescent protein gene (cfp) driven by the endogenous fast skeletal myosin light chain 2 gene (mlc2f) promoter. The transgenic marine medaka strains possessed multiple copies of transgene integrants and passed their fluorescent transgenes successfully to subsequent generations. Transgenic expression in skeletal muscles at both the mRNA and phenotypic levels was, overall, dependent upon transgene copy numbers. In the external phenotype, an authentic fluorescent color was dominant in the skeletal muscles of the transgenic fish and clearly visible to the unaided eye. The phenotypic fluorescent color presented differentially in response to different light-irradiation sources; the transgenics displayed a yellow-green color under normal daylight or white room light conditions, a strong green-glowing fluorescence under ultraviolet light, and a cyan-like fluorescence under blue light from a light-emitting diode.

Construction of High Sensitive Detection System for Endocrine Disruptors with Yeast n-Alkane-assimilating Yarrowia lipolytica

  • Cho, Eun-Min;Lee, Haeng-Seog;Eom, Chi-Yong;Ohta, Akinori
    • Journal of Microbiology and Biotechnology
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    • v.20 no.11
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    • pp.1563-1570
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    • 2010
  • To construct a highly sensitive detection system for endocrine disruptors (EDs), we have compared the activity of promoters with the n-alkane-inducible cytochrome P450 gene (ALK1), isocitrate lyase gene (ICL1), ribosomal protein S7 gene (RPS7), and the translation elongation factor-1${\alpha}$ gene (TEF1) for the heterologous gene in Yarrowia lipolytica. The promoters were introduced into the upstream of the lacZ or hERa reporter genes, respectively, and the activity was evaluated by ${\beta}$-galactosidase assay for lacZ and Western blot analysis for hER${\alpha}$. The expression analysis revealed that the ALK1 and ICL1 promoters were induced by n-decane and by EtOH, respectively. The constitutive promoter of RPS7 and TEF1 showed mostly a high level of expression in the presence of glucose and glycerol, respectively. In particular, the TEF1 promoter showed the highest ${\beta}$-galactosidase activity and a significant signal by Western blotting with the anti-estrogen receptor, compared with the other promoters. Moreover, the detection system was constructed with promoters linked to the upstream of the expression vector for the hER${\alpha}$ gene transformed into the Y. lipolytica with a chromosome-integrated lacZ reporter gene under the control of estrogen response elements (EREs). It was indicated that a combination of pTEF1p-hER${\alpha}$ and CXAU1-2XERE was the most effective system for the $E_2$-dependent induction of the ${\beta}$-galactosidase activity. This system showed the highest ${\beta}$-galactosidase activity at $10^{-6}\;M\;E_2$, and the activity could be detected at even the concentration of $10^{-10}\;M\;E_2$. As a result, we have constructed a strongly sensitive detection system with Y. lipolitica to evaluate recognized/suspected ED chemicals, such as natural/synthetic hormones, pesticides, and commercial chemicals. The results demonstrate the utility, sensitivity, and reproducibility of the system for identifying and characterizing environmental estrogens.

CB6F1-Tg rasH2 Mouse Carrying Human Prototype c-Ha-ras Gene As an Alternative Model For Carcinogenicity Testing For Pharmaceuticals

  • Usui, T.;Urano, K.;Suzuki, S.;Hioki, K.;Maruyama, Ch.;Tomisawa, M.;Ohnishi, Y.;Suemizu, H.;Yamamoto, S.
    • Toxicological Research
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    • v.17
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    • pp.293-297
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    • 2001
  • The international pharmaceutical and regulatory communities had been recognizing the limited utility of conventional rodent carcinogenicity study particularly on the second species, mouse, after intense investigation of carcinogenicity data base worldwide, and a new scheme for carcinogenicity testing for pharmaceuticals was proposed at the Expert Working Group on Safety in the International Conference on Harmonization (ICH) in 1996. CB6F 1-Tg rasH2 mouse carrying human prototype c-Ha-ras gene with its own promoter/enhancer is one oj the new carcinogenicity assay model for human cancer risk assessment. Studies have been conducted since 1992 to validate the transgenic (Tg) mice for rapid carcinogenicity test-ing, short term (26 weeks) studies with genotoxic (by Salmonella), non-genotoxic carcinogens, genotoxic non-carcinogens, non-genotoxic non-carcinogens revealed relatively high concordance oj the response of the Tg mouse with classical bioassay across classes of carcinogenic agents. Mechanistic basis for carcinogensis in the model are being elucidated in terms of the role of overexpression and/or point mutation of the transgene. This report review the initial studies of validation of the model and preliminary results of on-going ILSI HESI ACT project will be presented.

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