• Journal of Life Science
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• v.9 no.2
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• pp.52-56
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• 1999

The Raf, a cytoplasmic serine/thereonine protein kinase, acts as an important mediator of signals involving cell proliferation, differentiation and development. Multiple regulatory elements should participate in the expression of D-raf, Drosophila homolog of human c-raf-1. In order to search regulatory factors involved in the D-raf promoter activation, we accomplished the yeast one-hybrid screening using D-raf promoter region from bp-330 to -309 with respect to the transcription initiation site as bait. After screening, sixteen independent positive clones of ${\beta}$-galactosidase activties were identified and sequenced. Two clones having 94-98% identity with daughterless and one clone having 93% identity with escargot by Blast search among these clones were screened.

• The Journal of Korean Society of Virology
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• v.30 no.3
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• pp.211-217
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• 2000

Nef is a lentiviral protein involved in pathogenesis of AIDS, but its molecular mechanism of action remains incompletely understood. Here we report the isolation of the interacting protein with the HIV-1 Nef, using the yeast two hybrid system for expression cloning. One of the positive colonies was selected as the final candidate for the interacting protein gene. The nucleotide sequencing revealed that this interacting protein is Human Ikaros/LyF-1. This protein interacted with the C-terminal region of Nef specifically in yeast system, not with the N-terminal region. This interaction was also confirmed by in vitro binding assay.

• The Korean Journal of Mycology
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• v.40 no.4
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• pp.224-228
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• 2012

In order to screen interactor(s) of the Aspergillus nidulans ${\alpha}$-COP of COPI vesicle, we performed the yeast two hybrid screening by using the gene for A. nidulans ${\alpha}$-COP as a bait and identified ${\varepsilon}$-COP of the COPI vesicle as an interacting protein. The A. nidualns gene for the ${\varepsilon}$-COP was designated $aneA^+$ ($\underline{A.}$ $\underline{n}$idulans $\underline{e}$psi-lone-COP), which encoded 296 amino acid residues with high level of identity with orthologs from other fungi. Domain analyses with yeast two-hybrid system suggested that the interaction between ${\alpha}$-COP and ${\varepsilon}$-COP relied on the C-terminus of both proteins, and that the N-terminal WD domian of ${\alpha}$-COP and the TPR region of ${\varepsilon}$-COP were not essential but required for the enhancement of the interaction. These results indicate that the interaction mode between ${\alpha}$-COP and ${\varepsilon}$-COP of COPI vesicle is evolutionarily well conserved in eukaryotes.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.6
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• pp.893-904
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• 2006

To improve sensitivity of biosensor as yeast two-hybrid detection system for estrogenic activity of suspected chemicals, we tested effects of several combinations of the bait and fish components in the two-hybrid system on Saccharomyces cerevisiae inducted a chromosome-integrated lacZ reporter gene that was under the control of CYC1 promoter and the upstream Gal4p-binding element $UAS_{GAL}$. The bait components that were fused with the Gal4p DNA binding domain are full-length human estrogen receptor ${\alpha}$ and its ligand-binding domain. The fish components that were fused with the Gal4p transcriptional activation domain were nuclear receptor-binding domains of co-activators SRC1 and TIF2. We found that the combination of the full-length human estrogen receptor ${\alpha}$ with the nuclear receptor-binding domain of co-activator SRC1 was most effective for the estrogen-dependent induction of reporter activity among the two-hybrid systems so far reported. The relative strength of transcriptional activation by representative natural and xenobiotic chemicals was well correlated with their estrogenic potency that had been reported with other assay systems.

• Environmental Mutagens and Carcinogens
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• v.22 no.3
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• pp.175-182
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• 2002

Endocrine disruptors (EDs) are the chemicals that affect endocrine systems through activation or inhibition of steroid hormone response. It is necessary to have a good system to evaluate rapidly and accurately endocrine-disrupting activities of suspected chemicals and their degradation products. The key targets of EDs are nuclear hormone receptors, which bind to steroid hormones and regulate their gene transcription. We constructed a co-expression system of Gal4p DNA binding domain (DBD)- ligand binding domain of human estrogen receptor $\alpha$ or $\beta$, and Gal4p transactivation domain (TAD)-co-activator AIB-1, SRC-1 or TIF-2 in Saccharomyces cerevisiae with a chromosome-integrated lacZ reporter gene under the control of CYC1 promoter and Gal4p binding site (GAL4 upstream activating sequence, GAL4$_{UAS}$). Expression of this reporter gene was dependent on the presence of estrogen or EDs in the culture medium. We found that the two-hybrid system with combination of the hER$\beta$ LBD and co-activator SRC-1 was most effective in the xenoestrogen-dependent induction of reporter activity. The extent of transcriptional activation by those chemicals correlated with their estrogenic activities measured by other assay systems, indicating that this assay system is efficient and reliable for measuring estrogenic activity. The data in this research demonstrated that the yeast detection system using steroid hormone receptor and co-activator is a useful tool for identifying chemicals that interact with steroid receptors.s.

• Proceedings of the Korean Society of Potoscience Conference
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• 2006.06a
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• pp.19-19
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• 2006

• Proceedings of the Botanical Society of Korea Conference
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• 1998.07a
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• pp.117.2-118
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• 1998

• Proceedings of the Botanical Society of Korea Conference
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• 1998.07a
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• pp.119.2-120
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• 1998

• Bioindustry News
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• v.13 no.4
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• pp.16-21
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• 2000

• Journal of Korean Society of Water and Wastewater
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• v.19 no.1
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• pp.98-105
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• 2005

The effects of chlorination on the elimination of three estrogenic chemicals such as $17{\beta}$-estradiol (E2), nonylphenol (NP) and bis-phenol A (BPA) were investigated using yeast two-hybrid assay (YTA), estrogen receptor competition assay (ER-CA), and high-performance liquid chromatography/mass spectrometer (LC/MS). Results of YTA, ECA and the analysis of LC/MS indicated that the estrogenic activity of above mentioned three endocrine disruptors were significantly reduced as the result of chlorination. The decrease in estrogenic activity paralleled with decrease in estrogenic chemicals under the influence of free chlorine. One common characteristic of estrogenic chemicals is the presence of a phenolic ring. Considering that a phenolic ring is likely to undergo some sort of transformation in aqueous chlorination solution, the above mentioned results may be applied to the rest of the other estrogenic chemicals in natural waters.