• BMB Reports
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• v.50 no.9
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• pp.478-483
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• 2017

Budding yeast has dozens of prions, which are mutually dependent on each other for the de novo prion formation. In addition to the interactions among prions, transmissions of prions are strictly dependent on two chaperone systems: the Hsp104 and the Hsp70/Hsp40 (J-protein) systems, both of which cooperatively remodel the prion aggregates to ensure the multiplication of prion entities. Since it has been postulated that prions and the remodeling factors constitute complex networks in cells, a quantitative approach to describe the interactions in live cells would be required. Here, the researchers applied dual-color fluorescence cross-correlation spectroscopy to investigate the molecular network of interaction in single live cells. The findings demonstrate that yeast prions and remodeling factors constitute a network through heterogeneous protein-protein interactions.

• Biomolecules & Therapeutics
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• v.26 no.3
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• pp.313-321
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• 2018

Anti-cancer drug resistance is a major problem in colorectal cancer (CRC) research. Although several studies have revealed the mechanism of cancer drug resistance, molecular targets for chemotherapeutic combinations remain elusive. To address this issue, we focused on the expression of cellular prion protein ($PrP^C$) in 5-FU-resistant CRC cells. In 5-FU-resistant CRC cells, $PrP^C$ expression is significantly increased, compared with that in normal CRC cells. In the presence of 5-FU, $PrP^C$ increased CRC cell survival and proliferation by maintaining the activation of the PI3K-Akt signaling pathway and the expression of cell cycle-associated proteins, including cyclin E, CDK2, cyclin D1, and CDK4. In addition, $PrP^C$ inhibited the activation of the stress-associated proteins p38, JNK, and p53. Moreover, after treatment of 5-FU-resistant CRC cells with 5-FU, silencing of $PrP^C$ triggered apoptosis via the activation of caspase-3. These results indicate that $PrP^C$ plays a key role in CRC drug resistance. The novel strategy of combining chemotherapy with $PrP^C$ targeting may yield efficacious treatments of colorectal cancer.

• Korean Journal of Veterinary Research
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• v.49 no.1
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• pp.59-62
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• 2009

Susceptibility to chronic wasting disease (CWD) in cervid species has been associated with polymorphisms in the prion protein gene (PRNP). The single nucleotide polymorphisms (SNPs) were found in the PRNP of the Korean subspecies of Chinese water deer via analyses of the DNA sequences obtained from 34 individual deer. Two SNPs were detected at codons 77 and 100. One SNP at codon 77 encoding Glycine was determined to be a silent mutation but the other SNP detected at codon 100 induced an amino acid change, from Asparagine to Serine. The prion protein (PrP) amino acid sequence of the water deer showed 98.8-99.2% homology with those of American elk, white-tailed deer and mule deer. The PrP of the water deer contained amino acid residues closely related with CWD-susceptibility. This study is the first to describe genetic variations in the PRNP of the Korean subspecies of Chinese water deer.

• Korean Journal of Veterinary Service
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• v.28 no.4
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• pp.393-405
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• 2005

In prion pathogenesis, the structural conversion of the cellular prion protein $(PrP^c)$ to its abnormal isomer $(PrP^{Sc})$ is believed to be a major event. The susceptibility or resistance to natural sheep scrapie is associated with polymorphisms of host PrP gene (PRNP) at amino acid residues 136, to a lesser extent 154. The 112 residue in ovine PrP displays a natural polymorphism, Methionine to Threonine, which has not been thoroughly investigated. However the cell-free conversion assay showed that ARQ with Thr112 $(T_{112}ARQ)^{1)}$ presents lower convertibility to $PrP^{Sc}$than wild type ARQ $(M_{112}ARQ)$ [1] In this study we generated ovine recombinant PrPs of 112 allelic variants by metal chelate affinity chromatography and cation exchange chromatography. The final purity of the ovine PrP ARQ was more than $95\%$. These variants showed similar immunoreactivity against anti-PrP monoclonal antibodies in Western blot and ELISA. The refolded $M_{112}ARQ$ and $M_{112}ARQ$ presented the secondary structural content to similar extent via CD spectroscopy analysis. The inherited structural features of $M_{112}ARQ$ and $M_{112}ARQ$ under the different biophysical conditions are in the middle of investigation.

• Toxicological Research
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• v.28 no.1
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• pp.5-9
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• 2012

It has been shown that the accumulation of prion in the cytoplasm can result in neurodegenerative disorders. Synthetic prion peptide 106-126 (PrP) is a glycoprotein that is expressed predominantly by neurons and other cells, including glial cells. Prion-induced chronic neurodegeneration has a substantial inflammatory component, and an increase in the levels of matrix metalloproteinases (MMPs) may play an important role in neurodegenerative development and progression. However, the expression of MMPs in PrP induced rat astrocytes and microglia has not yet been compared. Thus, in this study, we examined the fluorescence intensity of CD11b positive microglia and Glial Fibrillary Acidic Protein (GFAP) positive astrocytes and found that the fluorescent intensity was increased following incubation with PrP at 24 hours in a dose-dependent manner. We also observed an increase in interleukin-1 beta (IL-$1{\beta}$) and tumor necrosis factor alpha (TNF-${\alpha}$) protein expression, which are initial inflammatory cytokines, in both PrP induced astrocytes and microglia. Furthermore, an increase MMP-1, 3 and 11 expressions in PrP induced astrocytes and microglia was observed by real time PCR. Our results demonstrated PrP induced activation of astrocytes and microglia respectively, which resulted in an increase in inflammatory cytokines and MMPs expression. These results provide the insight into the different sensitivities of glial cells to PrP.

• Proceedings of the Microbiological Society of Korea Conference
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• 1997.04a
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• pp.67.1-67.1
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• 1997

• 월간산업보건
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• s.201
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• pp.50-51
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• 2005

• Proceedings of the KSMRM Conference
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• 2005.09a
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• pp.79-83
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• 2005

• 한국환경농학회:학술대회논문집
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• 2009.07a
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• pp.283-297
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• 2009

Bovine spongiform encephalopathy (BSE) has become an important concern in food safety. Until now, 36 cases of BSE have been detected in Japan. Control programs have led to a decrease in the annual numbers, and Japan has now been categorized as a "controlled risk" country by the World Animal Health Organization (OIE). In spite of a worldwide decrease in the number of BSE cases, sporadic occurrences of atypical BSE cases have been reported. In Japan, 2 atypical BSE cases were confirmed. A Japanese L-type-BSE (BSE/JP24) has exhibited transmissibility to bovinized transgenic mice (TgBoPrP) it has a shorter incubation period than that of classical BSE. Although the origin of atypical BSE is obscure, risk analysis of newly emerged BSE prions of cattle and humans is required.

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.559-559
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• 2005