• Title/Summary/Keyword: promoters

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PREVENTION OF CANCER BY DIETARY FACTORS: TARGETING MAP KINASE/AP-1 SIGNAL TRANSDUCTION PATHWAYS

  • Dong, Zigang
    • Proceedings of the Korean Society of Toxicology Conference
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    • 2001.10a
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    • pp.29-30
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    • 2001
  • MAP kinase/ AP-1 signal transduction components are rapidly initiated by many extracellular stimuli, especially environmental carcinogens. We have investigated the role of MAP kinases (Erks, JNKs, and p38 kinases) and AP-1 signal transduction pathways in the process of cell transformation and carcinogenesis. Incubation of Cl 41 cells with tumor promoters such as TPA, EGF, arsenic, or TNF-$\alpha$ led to cell transformation and activation of MAP kinases.(omitted)

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Agonists of the Dioxin Receptor: Environmental Contaminants, Food Constituents, Microbial Metabolites, and Tumor Promoters

  • Schrenk, Dieter
    • Proceedings of the Korean Society of Toxicology Conference
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    • 2002.11b
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    • pp.90-105
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    • 2002
  • The dioxin- or aryl hydrocarbon receptor (AhR) is a member of the Per-Arnt-Sim family of nuclear transcription factors exhibiting a basic helix-loop-helix structure. In its non-ligated state the AhR is associated with hsp 90 and the immunophilin-type XAP2. Upon ligand binding the associated proteins are released, the receptor dimerizes with the AhR nuclear trans locator protein Arnt, and binds to XREs (xenobiotic-responsive elements) in the 5'-flanking region of responsive genes thus modulating their transcription.(omitted)

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Induction of Reactive Oxygen Species and Malignant Transformation by Tcdd Through Metabolic Formation of Catechol Estrogens

  • Na, Hye-Kyung;Chen, Zhi-Hua;Kim, Jung-Hwan;Surh, Young-Joon
    • Proceedings of the Korean Society of Toxicology Conference
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    • 2003.10b
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    • pp.188-188
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    • 2003
  • 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD), a prototype of halogenated aromatic hydrocarbons, is a persistent environmental contaminant and one of the most powerful tumor promoters. The molecular mechanism underlying induction of tumor promotion by TCDD has not been elucidated.(omitted)

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Identification of a Promoter Motif Involved in Curtovirus Sense-Gene Expression in Transgenic Arabidopsis

  • Hur, Jingyung;Choi, Eunseok;Buckley, Kenneth J.;Lee, Sukchan;Davis, Keith R.
    • Molecules and Cells
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    • v.26 no.2
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    • pp.131-139
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    • 2008
  • Expression of the seven open reading frames (ORFs) of single-stranded DNA Curtoviruses such as Beet curly top virus (BCTV) and Beet severe curly top virus (BSCTV) is driven by a bi-directional promoter. To investigate this bidirectional promoter activity with respect to viral late gene expression, transgenic Arabidopsis plants expressing a GUS reporter gene under the control of either the BCTV or BSCTV bi-directional promoter were constructed. Transgenic plants harboring constructs showed higher expression levels when the promoter of the less virulent BCTV was used than when the promoter of the more virulent BSCTV was used. In transgenic seedlings, the reporter gene constructs were expressed primarily in actively dividing tissues such as root tips and apical meristems. As the transgenic plants matured, reporter gene expression diminished but viral infection of mature transgenic plants restored reporter gene expression, particularly in transgenic plants containing BCTV virion-sense gene promoter constructs. A 30 base pair conserved late element (CLE) motif was identified that was present three times in tandem in the BCTV promoter and once in that of BSCTV. Progressive deletion of these repeats from the BCTV promoter resulted in decreased reporter gene expression, but BSCTV promoters in which one or two extra copies of this motif were inserted did not exhibit increased late gene promoter activity. These results demonstrate that Curtovirus late gene expression by virion-sense promoters depends on the developmental stage of the host plant as well as on the number of CLE motifs present in the promoter.

Human transcription factor YY1 could upregulate the HIV-1 gene expression

  • Yu, Kyung Lee;Jung, Yu Mi;Park, Seong Hyun;Lee, Seong Deok;You, Ji Chang
    • BMB Reports
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    • v.53 no.5
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    • pp.248-253
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    • 2020
  • Gene expression in HIV-1 is regulated by the promoters in 5' long-terminal repeat (LTR) element, which contain multiple DNA regulatory elements that serve as binding sites for cellular transcription factors. YY1 could repress HIV-1 gene expression and latent infection. Here, however, we observed that virus production can be increased by YY1 over-expression and decreased under YY1 depleted condition by siRNA treatment. To identify functional domain(s) of YY1 activation, we constructed a number of YY1 truncated mutants. Our data show that full-length YY1 enhances the viral transcription both through U3 and U3RU5 promoters. Moreover, the C-terminal region (296-414 residues) of YY1 is responsible for the transcriptional upregulation, which could be enhanced further in the presence of the viral Tat protein. The central domain of YY1 (155-295 residues) does not affect LTR activity but has a negative effect on HIV-1 gene expression. Taken together, our study shows that YY1 could act as a transcriptional activator in HIV-1 replication, at least in the early stages of infection.

Effect of Cutting Dates and Rooting Promoters on Rooting of Rhododendron mucronulatum Turcz. (삽목시기(揷木時期) 및 발근촉진제(發根促進劑) 처리가 진달래(Rhododendron mucronulatum Turcz.)의 발근(發根)에 미치는 영향(影響))

  • Hwang, Seong Kon;Hwang, Hwan Joo;Kim, Ki Sun
    • Horticultural Science & Technology
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    • v.16 no.1
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    • pp.33-36
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    • 1998
  • This study was carried out to examine the effects of cutting dates and rooting promoters on rooting of the Rhododendron mucronulatum Turcz. The rooting percentage in greenwood cutting was high in June and decreased after July 3, when reproductive growth began. The best rooting percentage(92.5%) occurred when cutting was completed on June 12. There was no difference in rooting potentials between the greenwood straight cutting and the greenwood heel cutting. Cuttings of R. mucronulatum for. albiflora showed high rooting percentage(85%) similar to the cuttings of R. mucronulatum. Dipping cuttings in NAA $2,000mg{\cdot}L^{-1}$ solution for 15 sec increased the rooting percentage up to 97.5%, and also promoted root growth.

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