• Development and Reproduction
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• v.4 no.1
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• pp.29-35
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• 2000

A phosphatidylinositol 3-kinase (PI3K) is a upstream component of insulin signaling by which protein synthesis can be stimulated in many systems. To elucidate involvement of PI3K and its downstream mammalian target of rapamycin (mTOR) in the insulin signaling in pleimplantation mouse embryos, 8-cell embryos were cultured to blastocysts in the presence or absence of insulin and／or inhibitor drugs. The number of blastomeres per blastocyst, protein synthesis, and protein phosphorylation were examined. There was significant difference in embryonic development to blastocyst stage and hatching was potentiated by the insulin supplementation. The increase in the mean celt numbers per blastocyst was apparent in the insulin culture. Wortmannin, a PI3K inhibitor and rapamycin, an inhibitor of mTOR abolished the stimulatory effect of insulin on morphological development mitosis and protein synthesis. In autoradiography, phosphoproteins pp22 and pp30 which undergo phosphorylation in response to insulin were identified. Taken together, it can be suggested that PI3K and mTOR engaged in insulin signaling in the mouse embryo 8-cell onward and mediate embryotropic offset of insulin.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2001.02a
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• pp.68-70
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• 2001

착상전 초기배아에서 용해된 Matrigedl에 의한 배아의 형태발생, 세포증식, apoptosis 및 UPK활성의 변화를 조사하였다. Matrigel (0.5%)을 첨가한 배양액에서 체외배양된 2-세포기 배아의 형태발생 및 포배당 세포수가 증가되었으며 (GF>GFR>control) 포배의 TUNEL 양성 할구 및 배아내 caspase-3의 활성이 감소되었다. (GF

• Journal of Life Science
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• v.30 no.4
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• pp.402-409
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• 2020

Nervous necrosis virus (NNV) contains a bi-segmented viral genome, RNA1 (3.4 kb, RdRp), and RNA2 (1.4 kb, capsid protein) in a small particle (25 nm). Despite its extremely compact size, NNV has caused serious damage by infecting approximately 120 fish species worldwide since it was first reported in the late 1980s. In order to minimize the damage caused by NNV infection and develop effective vaccines, it is necessary to understand the intra cellular signaling system according to NNV infection. NNV infection induces cell cycle arrest at the G1 phase via the p53-dependent pathway to use the cellular system for its replication. Otherwise, host cells recognize NNV infection through the RIG-1-like receptor (RLR) signaling pathway to control the virus and infected cells, and then ISGs required for antiviral action are activated via the IFN signaling pathway. Moreover, apoptosis of infected cells is triggered by the unfolded protein response (UPR) through ER stress and mitochondria-mediated cell death. Cell signaling studies on the NNV infection mechanisms are still at an early stage and many pathways have yet to be identified. Understanding the various disease-specific cellular signaling systems associated with NNV infection is essential for rapid and accurate diagnosis and vaccine development.

• Journal of Plant Biotechnology
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• v.36 no.1
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• pp.59-63
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• 2009

Calcium ion ($Ca^{2+}$) is thought to play the important role as a second messenger for signal transduction that results in various physiological responses to cope with developmental programs and environmental changes in plant. In plant cells, the central vacuole functions as a major calcium store, which is important for both signal transduction and preventing cytotoxicity. Although there is evidence for the biochemical characterizations of a calmodulin-regulated $Ca^{2+}$-ATPase (ACA11) localized to vacuole membrane, the biological function to ACA11 in plant has not been verified. In this study, we show that the cell death as the hypersensitive response (HR) in mature leaves is induced in transgenic plant of a vacuole ACA-type $Ca^{2+}$-ATPase, ACA11. Evidence that cell death phenotype is the result of ACA11 gene silencing is provided by Western blot assay using membrane fraction proteins extracted from transgenic plant. The 3, 3'-diaminobenzidine (DAB) staining study provides that the cell death is caused by the increase of reactive oxygen species (ROS) in mature leaves of transgenic plants.

• Korean Journal of Biological Psychiatry
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• v.2 no.2
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• pp.252-256
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• 1995

Corticotropin-releasing factor(CRF)를 분비하는 배양세포주는 CRF의 세포내 조절을 연구하는데 있어 훌륭한 체계가 된다. BE(2)-M17 및 BE(2)-C 세포주는 CRF를 생산하고 분비하며 forskolin 처치에 반응하는 것으로 알려져 있다. 저자들은 이들 세포주에 phorbol 에스테르, 즉 phorbol 12-myristate 13-acetate(TPA) 0.8, 4, 10, 20 nM, 및 nitric oxide(NO)의 신호전달 경로의 자극제(1-${\mu}M$ nitroprusside)와 차단제($1{\mu}M$ nitroprusside+$300{\mu}M$ $N^G$-methyl-D-arginine), 그리고 interleukin-$1{\alpha}$ (IL $1{\alpha}$ ; 4, 20, 100, 500 pM)를 처치하여 CRF를 의미있게 증가시켰으나 세포외 분비는 C 세포에서만 변화되었다. NOS계의 자극제와 차단제는 C 세포의 forskolin 효과를 의미있게 변화시켰다. IL$1{\alpha}$는 두 세포주에 대한 영향이 없었다. 상기 제제들에 대한 이들 세포의 반응이 중추신경계 CRF 신경들과 관련하여 논의되었다.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.95-95
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• 2003

Inositol은 세포의증식 및 정보전달과정에 관여하는 phosphatidylinositol (PI)의 구성성분으로서 중요한 세포내 기능을 수행한다. P1는 세포내에서 특이적 인산화효소에 의하여 Pl4-phosphate(PIP), Pl4,5-phosphate($PIP_2$)로 변환되며 PIP$_2$는 phospholipase C(PLC)에 의하여 세포내 second messengers인 1,2-diacylglycerol (DAG)와 inositol 1,4,5-triphosphate ($IP_3$)로 변환된다. 이렇게 생산된 DAG와 IP3는 각각 protein kinase C의 활성과 $Ca^{2++}$의 동원에 관여하여 다양한 세포내 신호전달에 관여하는 것으로 보고되고 있다. 또한 mouse에서 $IP_3$의 작용에 의한 $Ca^{2++}$의 상승은 난모세포의 성숙분열이 촉진되고 돼지 난포세포에 있어서도 PI대사가 일어나고 있는 것으로 보고되고 있다. 본 연구에서는 돼지 미성숙 난모세포의 성숙과 단위발생에 미치는 inositol의 영향을 확인하기 위하여 실시하였다. inositol의 농도가 난포란의 성숙에 미치는 영향을 검토하기 위하여 난포란을 각각 $150 \mu mole$, $250 \mu mole$, $350 \mu mole$, inositol을 포함하는 Whitten's 배양액에서 44시간 성숙시킨 결과 $93.57 \pm 4.21, 93.91 \pm 2.71, 92.96 \pm 3.58%$가 성숙되어 대조구의 $87.10 \pm 4.21$보다 유의적(P<0.05)으로 차이를 나타내었다. 난포란의 등급에 따른 inositol의 영향을 확인하기 위하여 형태적으로 난구세포가 치밀한 난포란과 난구세포가 치밀하지 않은 난포란을 $250 \mu mole$ inositol을 포함하는 Whitten's 배양액에서 성숙을 유도한 결과 난구세포가 치밀한 난포란과 난구세포가 치밀하지 않은 난포란에서 inositol을 첨가하였을 때 성숙율은 각각 $95.35 \pm 2.22와 63.55 \pm 8.12$로 inositol을 첨가하지 않은 대조구보다($89.21 \pm 3.69와 48.56 \pm 8.99$) 유의적인 차이를 보였다. 난구세포가 inositol에 의한 성숙에 미치는 영향을 확인하기 위하여 난구세포를 제거한 난포란을 inositol을 포함하는 배지에서 성숙을 유도한 결과 inositol을 첨가하지 않은 처리구보다 양호한 성숙율을 보였다.

• Microbiology and Biotechnology Letters
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• v.30 no.3
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• pp.235-240
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• 2002

Streptomycetes is a group of Gram-positive soil bacteria that growas a branching vegetative mycelium leading to the formation of spores, and display a physiological differenti-ation related to the synthesis of many secondary metabolites including antibiotics. Their complex life cycle and multicellular differentiation require various levels of regulation and types of signal transduction systems including eukaryotic-type serine/threonine protein kinases and prokaryotic-type histidine/aspartic acid protein kinases. Akt kinase that was found in cells is a sorine/threonine kinase controlling signal pathway for multi-tude of important cellular events. The activation or inactivation of Akt kinase in the cell is one of the critical regulatory points to deliver cell proliferation, differentiation, survival or apoptosis signal. To find the regula-tory protein homologous to Akt in Streptomyces, the fluorescien-labeled synthetic peptide (FITC-TRRSR-TESIT) was designed from the consensus sequence of target proteins for Akt kinase. From the difference of the mobility between the nonphosphorylated and phosphorylated synthetic peptides on Agarose gel electro-phoresis, the Akt-phosphorylating activity was monitored. The cell-free extract prepared from Streptomyces griseus IFO 13350 and the Akt homologous protein was purified by ammonium sulfate fractionation and many steps of column chromatographies such as, DEAE-Sepharose, Mono Q, Resource Phenyl-Soporose and Gel permeation column chromatographies. As a result, the protein phosphorylating the fluorescien-labeled Akt substrate was identified and it's molecular weight was estimated as 39 kDa on SDS-PAGE.

• Journal of Life Science
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• v.24 no.12
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• pp.1378-1382
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• 2014

Phospholipase D (PLD) catalyzes the hydrolysis of phospholipid to phosphatidic acid (PA), a lipid secondary messenger. Two forms of PLD isozymes, phosphatidylcholine-specific PLD1 and PLD2, have been identified. PLD has emerged as a critical regulator of cell proliferation and survival signaling, and dysregulation of PLD occurs in a various illnesses, including cancer. PLD activity is essential for cell survival and protection from apoptosis. Overexpression of PLD isozymes or PLD-generated PA attenuates the expression of apoptotic genes and confers resistance to apoptosis. The apoptosis-related molecular mechanisms of PLD remain largely unknown. Recently, the dynamics of PLD turnover during apoptosis have been reported. The cleavage of PLD isozymes as specific substrates of caspase differentially regulates apoptosis. PLD1 is cleaved at one internal site, and PLD2 is cleaved two sites at the front of the N-terminus. The cleavage of PLD1 reduces its enzymatic activity, probably via the dissociation of two catalytic motifs, whereas the cleavage of PLD2 does not affect the catalytic motifs and its activity. Thus, PLD2 maintains antiapoptotic capacity, despite its cleavage. Therefore, the differential cleavage pattern of PLD isozymes by caspase affects its enzymatic activity and antiapoptotic function. Thus, PLD is considered a potential target for cancer therapy. We summarize recent studies regarding the functional role of PLD in apoptosis.

• Korean Journal of Food Science and Technology
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• v.53 no.6
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• pp.722-730
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• 2021

In this study, we aimed to elucidate the intracellular signaling pathways for macrophage activation by the polysaccharide GBW-II purified from ginseng berry. GBW-II consists of 14 different sugars, including rarely observed sugars such as 2-O-methyl-xylose, apiose, aceric acid, 2-keto-3-deoxy-D-manno-2-octulosonic acid, and 2-keto-3-deoxy-D-lyxo-2-heptulosaric acid, which are typical RG-II component sugars. GBW-II enhanced the production of IL-6 and TNF-α in RAW 264.7 cells. In experiments evaluating specific inhibitor activity, it was found that the production of IL-6 was suppressed by inhibitors of SB, PD, and BAY, and the production of TNF-α was suppressed by PD and BAY. The experiments with neutralizing antibodies showed that TLR4 was involved in the stimulation of IL-6 production by GBW-II in RAW 264.7 cells, whereas TNF-α production was regulated through SR and TLR2. These results suggest that GBW-II activates the MAPK and NF-κB pathways via several macrophage receptors, including SR, TLR2, and TLR4, and subsequently induces the secretion of IL-6 and TNF-α.

• Journal of Life Science
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• v.29 no.1
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• pp.105-111
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• 2019

In recent years, progress has been made in the search for the development of new anti-cancer agents by employing specific inhibitors of histone deacetylase (HDAC)-6 to block signal transduction pathways in cancer cells. This study examined the effects of tubastatin A (TubA), an HDAC-6 inhibitor, on the growth and development of immature oocytes in murine ovaries using RNA sequencing analysis. The results from a gene set enrichment analysis (GSEA) indicated that the expression of most of the gene sets involved in the cell cycle and control and progression of meiosis decreased in the TubA-treated group as compared with that in germinal vesicle (GV) stage oocytes. In addition, an ingenuity pathway analysis (IPA) suggested that TubA not only caused increased expression of p53 and pRB and decreased expression of CDK4/6 and cyclin D but also caused elevated expression of genes involved in the control of the DNA check point in G2/M stage oocytes. These results suggest that TubA may induce cell cycle arrest and apoptosis through the induction of changes in the expression of genes involved in signal transduction pathways associated with DNA damage and the cell cycle of immature oocytes in the ovary.