• BMB Reports
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• v.49 no.3
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• pp.159-166
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• 2016

Several members of tumor necrosis factor receptor (TNFR) superfamily that these members activate caspase-8 from death-inducing signaling complex (DISC) in TNF ligand-receptor signal transduction have been identified. In the extrinsic pathway, apoptotic signal transduction is induced in death domain (DD) superfamily; it consists of a hexahelical bundle that contains 80 amino acids. The DD superfamily includes about 100 members that belong to four subfamilies: death domain (DD), caspase recruitment domain (CARD), pyrin domain (PYD), and death effector domain (DED). This superfamily contains key building blocks: with these blocks, multimeric complexes are formed through homotypic interactions. Furthermore, each DD-binding event occurs exclusively. The DD superfamily regulates the balance between death and survival of cells. In this study, the structures, functions, and unique features of DD superfamily members are compared with their complexes. By elucidating structural insights of DD superfamily members, we investigate the interaction mechanisms of DD domains; these domains are involved in TNF ligand-receptor signaling. These DD superfamily members play a pivotal role in the development of more specific treatments of cancer.

• 대한핵의학회:학술대회논문집
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• 2004.11a
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• pp.411.1-411.1
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• 2004

• Proceedings of the Zoological Society Korea Conference
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• 1999.10b
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• pp.253.1-253
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• 1999

No Abstract, See Full Text

• The Plant Pathology Journal
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• v.28 no.3
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• pp.227-238
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• 2012

Mitogen-activated protein kinase (MAPK) cascades are conserved signaling modules in the eukaryotic cells. They are involved in many major cell processes in fungi such as stress responses, vegetative growth, pathogenicity, secondary metabolism and cell wall integrity. In this review, we summarized the advances of research on the MAPK signaling pathways in Alternaria species. As major phytopathogenic fungi, Alternaria species reduce crop production. In contrast to the five MAPK pathways known in yeast, only three MAPK pathways as Fus3/Kss1-type, Hog1-type, and Slt2-type have been characterized in Alternaria. The Fus3/Kss1-type MAPK pathway participates in regulation of vegetative growth, conidiation, production of some cell-wall-degrading enzymes and pathogenicity. The Hog1-type pathway is involved in osmotic and oxidative stress, fungicides susceptibility and pathogenicity. The Slt2-type MAP kinases play an important role on maintaining cell wall integrity, pathogenicity and conidiation. Although recent advances on the MAPK pathways in Alternaria spp. reveal many important features on the pathogenicity, there are many unsolved problems regarding to the unknown MAP kinase cascade components and network among other major signal transduction. Considering the economic loss induced by Alternaria spp., more researches on the MAPK pathways will need to control the Alternaria diseases.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.10
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• pp.5925-5928
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• 2013

Objective: This study aimed to examine the relationship between expression of mammal target of rapamycin (mTOR) and phosphorylation of mTOR (p-mTOR) protein in the PI3K/Akt/mTOR signaling pathways in gastrointestinal stromal tumors and relatiuonships with clinical factors. Methods: Immunohistochemistry was used to detect the expression of the associated proteins mTOR, p-mTOR, and phosphorylation of the tumor suppressor genes PTEN, P27, VEGF, and EGFR in 40 cases of gastrointestinal stromal tumors, with division into a very low and low risk group as well as a moderate and high risk group. Results: The positive rate of mTOR and p-mTOR was significantly increased in the moderate and high risk group compared with the very low and low risk group. The difference was statistically significant (P<0.05). When grouped according to size, the positive mTOR expression rate exhibited a statistical difference (P<0.05), which was significantly increased in the group of tumors larger than 5 cm. The difference in the positive mTOR and p-mTOR expression rate exhibit no statistical significance among the PTEN, P27, VEGF, and EGFR expression subgroups (P>0.05). Conclusion: The different expressions of mTOR and p-mTOR in the signal transduction pathway of gastrointestinal stromal tumor in the different degree-of-risk groups suggested that the mTOR and p-mTOR of the signal transduction pathway serve an important function in the occurrence and development of gastrointestinal stromal tumors.

• Korean Journal of Animal Reproduction
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• v.20 no.4
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• pp.395-412
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• 1997

Mammalian eggs are ovulated arrested at meiotic metaphase II until fertilization. Generally in mammals, fertilization results in a series of intracellular calcium oscillations that are mediated by inositol triphosphate (IP$^3$) or cyclic adenosine diphosphoribose (cADPr). The high levels of maturation promotion factor (MPF) within the cell decrease, pronuclei form, the cytoskeleton is reorganized and proteins are post-translationally modified. If all is normal, the newly formed embryo initiates the developmental program specific to that species. Artificial methods of producing these effects in pig oocytes are discussed. One potential mechanism mediated via a signal transduction pathway is present in pig oocytes. Stimulation of this pathway leads to the early events following fertilization, and electrical stimulation leads to apparently normal de v velopment to day 12. Further studies are needed to determine which mechanism(s) the sperm uses to initiate development.

• Mycobiology
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• v.38 no.4
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• pp.302-309
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• 2010

Formic acid is a representative carboxylic acid that inhibits bacterial cell growth, and thus it is generally considered to constitute an obstacle to the reuse of renewable biomass. In this study, Saccharomyces cerevisiae was used to elucidate changes in protein levels in response to formic acid. Fifty-seven differentially expressed proteins in response to formic acid toxicity in S. cerevisiae were identified by 1D-PAGE and nano-liquid chromatography-tandem mass spectrometry (nano-LC-MS/MS) analyses. Among the 28 proteins increased in expression, four were involved in the MAP kinase signal transduction pathway and one in the oxidative stress-induced pathway. A dramatic increase was observed in the number of ion transporters related to maintenance of acid-base balance. Regarding the 29 proteins decreased in expression, they were found to participate in transcription during cell division. Heat shock protein 70, glutathione reductase, and cytochrome c oxidase were measured by LC-MS/MS analysis. Taken together, the inhibitory action of formic acid on S. cerevisiae cells might disrupt the acidbase balance across the cell membrane and generate oxidative stress, leading to repressed cell division and death. S. cerevisiae also induced expression of ion transporters, which may be required to maintain the acid-base balance when yeast cells are exposed to high concentrations of formic acid in growth medium.

• Molecules and Cells
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• v.39 no.3
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• pp.186-194
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• 2016

Epidemiological evidence suggests that bone is especially sensitive to oxidative stress, causing bone loss in the elderly. Previous studies indicated that human amnion-derived mesenchymal stem cells (HAMSCs), obtained from human amniotic membranes, exerted osteoprotective effects in vivo. However, the potential of HAMSCs as seed cells against oxidative stress-mediated dysfunction is unknown. In this study, we systemically investigated their antioxidative and osteogenic effects in vitro. Here, we demonstrated that HAMSCs significantly promoted the proliferation and osteoblastic differentiation of $H_2O_2$-induced human bone marrow mesenchymal stem cells (HBMSCs), and down-regulated the reactive oxygen species (ROS) level. Further, our results suggest that activation of the ERK1/2 MAPK signal transduction pathway is essential for both HAMSCs-mediated osteogenic and protective effects against oxidative stress-induced dysfunction in HBMSCs. U0126, a highly selective inhibitor of extracellular ERK1/2 MAPK signaling, significantly suppressed the antioxidative and osteogenic effects in HAMSCs. In conclusion, by modulating HBMSCs, HAMSCs show a strong potential in treating oxidative stress- mediated bone deficiency.

• YAKHAK HOEJI
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• v.39 no.6
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• pp.661-665
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• 1995

Ginsenoside-Rg$_{1}$(G-Rg$_{1}$) has been shown to stimulate DNA synthetic activity in SK-HEP-1 cells. This study was therefore designed to determine in SK-HEP-1 cells whether the stimulatory effect of G-Rg$_{1}$ may be mediated by protein kinase C (PKC) which is known to play a key role in the signal transduction pathway leading to the cell proliferation. Using the tn situ PKC assay method, the PKC enzyme activity was determined in SK-HEP-1 cell cultures in response to G-Rg$_{1}$ at 3*10$^{-5}$ M or phorbol 12-myristate 13-acetate(PMA) at 10$^{-6}$ M which in the enzyme activity by 1.5- and 7-fold, respectively. Furthermore, G-Rg$_{1}$, was also able to synergistically increase the enzyme activity by 11-fold m the cell cultures in the presence of PMA. These stimulatory effects of G-Rg$_{1}$ or PMA on the DNA synthetic activity and the PKC activity were ablished by a specific PKC inhibitor, GF109203X. These results suggest that the stimulatory effect of G-Rg$_{1}$ on the DNA synthetic activity may be partly due to stimulation of PKC-mediated signal transduction pathway leading to the proliferation of SK-HEP-1 cells.

• Journal of fish pathology
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• v.20 no.1
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• pp.71-81
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• 2007

Photobacterium damselae subsp. damselae and 4 Vibrio spp.(V. anguillarum, V. splendidus, V. harveyi and V. ordalii) were isolated from the diseased olive flounders, Paralichthys olivaceus. The isolates were tested on the pathogenicity in vitro. The properties of extracellular products(ECPs) were investigated with enzymatic activities, hemolytic activities toward the sheep and olive flounder erythrocytes, and cytotoxicity activities on the cell-line. And potential signal transduction pathways of the bacterial internalization were detected by using signal transduction inhibitors. P. damselae was high in phospholipase activity, hemolytic activity to olive flounder erythrocytes and cytotoxicity activity. And P. damselae had diversified internalizing pathways as compared to isolated vibrios. Therefore, these activities may be related with pathogenicity of P. damselae.