• 한국미생물·생명공학회지
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• 제46권2호
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• pp.91-101
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• 2018

The aim of this study was to transfer the 18.5 kb gene clusters coding for 17 genes from Lactobacillus rhamnosus to Lactococcus lactis subsp. cremoris MG1363 in order to determine the effect of host on exopolysaccharide (EPS) production and to provide a model for studying the phosphorylation of proteins which are proposed to be involved in EPS polymerization. Lactobacillus rhamnosus RW-9595M and ATCC 9595 have 99% identical operons coding for EPS biosynthesis, produced different amounts of EPS (543 vs 108 mg/l). L. lactis subsp. cremoris MG1363 transformed with the operons from RW-9595M and ATCC 9595 respectively, produced 326 and 302 mg/l EPS in M17 containing 0.5% glucose. The tyrosine protein kinase transmembrane modulator (Wzd) was proposed to participate in regulating chain elongation of EPS polymers by interacting with the tyrosine protein kinase Wze. While Wzd was found in phosphorylated form in the presence of the phosphorylated kinase (Wze), no phosphorylated proteins were detected when all nine tyrosines of Wzd were mutated to phenylalanine. Lactococcus lactis subsp. cremoris could produce higher amounts of EPS than other EPS-producing lactococci when expressing genes from L. rhamnosus. Phosphorylated Wzd was essential for the phosphorylation of Wze when expressed in vivo.

• BMB Reports
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• 제39권6호
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• pp.774-781
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• 2006

Human nucleolar phosphoprotein p140 (hNopp140) is a nucleolar phosphoprotein that can bind to doxorubicin, an anti-cancer agent. We have examined the interaction between hNopp140 and doxorubicin as well as the folding property of hNopp140. Also, the effects of ATP and phosphorylation on the affinity of hNopp140 to doxorubicin are investigated by affinity dependent co-precipitation and surface plasmon resonance methods. Doxorubicin preferentially binds to un-phosphorylated form of hNopp140 with a $K_D$ value of $3.3\;{\times}\;10^{-7}$ M. Furthermore, doxorubicin reduces the protein kinase CK2-dependent phosphorylation of hNopp140, indicating that doxorubicin may perturb the cellular function of hNopp140 by reducing the protein kinase CK2-dependent phosphorylation of hNopp140. Low contents of the secondary structures of hNopp140 and the fast rate of proteolysis imply that hNopp140 has a high percentage of flexible regions or extended loop structures.

• 동의생리병리학회지
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• 제19권4호
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• pp.1022-1026
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• 2005

To clarify the toxic effect on cultured neonatal mouse cerebral neurons damaged by ischemia, we examined the cytotoxicity induced by ischemia and the protective effect of antioxidant and AMPA/kainate receptor antagonist against ischemia-induced cytotoxicity on cultured cerebral neurons. For this study, mice were administrated with 20ug/kg cyclothiazide or 50U/kg vitamin E via intraperitoneal injection for 2 hours before ischemic induction. After cell culture for 7 days, cell viability, amount of neurofilament and protein kinase C activity were examined. Ischemia decreased significantly cell viability, amount of neurofilament and the increase of protein kinase C activity in these cultures. In the protective effect, vitamin I showed remarkably the increase of cell viability and amount of neurofilament, and the decrease of protein kinase C activity but, cyclothiazide did not showed any protective effect on ischemia-induced cytotoxicity. From these results, it is suggested that vitamin I is effective in blocking the neurotoxicity induced by ischemia, but cyclothiazide as a AMPA/kainate receptor antagonist is not.

• 한국동물학회지
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• 제35권2호
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• pp.161-172
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• 1992

In the short-term treahent of 12-0-tetradecanoylphorbol-13-acetate (TPA) or platelet-derived growth factor (PDGF), the'Wh and PDGF induced the Protein Kinase C (PKC) activation and migration from the cytoplasm to the peripheral nulcear membrane. And the activated PKC which was directly or indirectly stimulated by TPA or PDGF Phosphorylated many kinds of PKC's targeting proteins and induces various biological responses. Especially, the cytoplasmic PKC was phosphorylated within 1 hr and 10 min by TPA-and PDGF-treahent respectivelv. In the long-term treatment of TPA or PDGF, both of them induced the down-regulation and translocation of PKC in the mvoblasts. The down-regulation of PKC isozyrnes, the pattern of PKC I and ll was similar to the PKC 111 isozpnes in the cytoplasm. But in the nucleolus, the TPA did not induce and down-regulation or the inhibition of the immunoreactivity of PKC III antibody. This investigation indicates that each isozvmes of PKC mal be performed the different effects to the down-regulation of the cytoplasm or nucleolus. And douvn-regulated myoblasts contained low immunoreactivity of PKC antibodies.

• 대한수의학회지
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• 제38권1호
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• pp.9-15
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• 1998

To investigate the involvement of protein kinase C(PKC) isoenzyme in the testes which control spermatogenesis and hormone secretion, we examined cellular distribution of four types of PKC $\alpha$, ${\beta}I$, ${\delta}$ and ${\theta}$ in the horse testes using PKC antisera by western blot analysis and immunohistochemistry. By the western blot analysis, PKC $\alpha$ and ${\beta}I$ were detected at 82KD, while PKC ${\delta}$ and ${\theta}$ were detected at 80KD in the testes of both juvenile and adult horses. In juvenile horse, PKC $\alpha$, ${\delta}$ and ${\theta}$ except ${\beta}I$ were not detected in the cells of the testes, whereas PKC ${\beta}I$ was immunoreacted with only in spermatocytes. In adult, PKC $\alpha$, ${\beta}I$, ${\delta}$ and ${\theta}$isoenzymes were localized in interstitial cells of the testes. In the seminiferous tubules, PKC ${\beta}I$ is localized in spermatocyte, spermatid and spermatozoa, while PKC ${\delta}$ is localized only in spermatids. We suggest that this is a first report to localize PKC in the testes of horse and PKC isoenzymes are upregulated in the cells of horse testes depending on ages. These findings also suggest that certain PKC isoenzyme plays an important role in the signal transduction of spermatogenic cells and interstitial cells in horse testes.

• 한국동물학회지
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• 제36권4호
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• pp.487-495
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• 1993

TRH (Thvrotropin-Releasing Hormone) known to regulate the transcription of the TSH (Thyroid-Stimulating Hormones gene in pituitary cells, but little is understood about the mechanism(sl involved. re present study was attempted to elucidate the role of Ca2+ movement through the voltage-gated channels in the regulation of TSH gene transcription. The c-fos is one of immediate early genes and used as model system for the investigation of signaling pathwavs involved in various stimuli. The changes of c-fos mRNA levels were determined after treatment of various agents using Northern and slot hybridization analysis. The c-fos mRNA was rapidly and transiently induced by TRH (about 3-fold) in GH3 cells and this induction was repressed by calcium chelating agent (EGTA), calcium channel blocker (verapamil) anti protein kinase C inhibitor (aminoacridine). The abilities of forskolin (adenvlate cvclase activators, PMA (protein kinase C activator), and A23187 (calcium ionophore) to affect c-ios gene transcription, either alone or in combination with TRH were tested in the same cells. All of them significantly increased the level of c-fos mRUA. However, no additive relationship was observed in all combined treatments except forskolin. These results suggest that TRH action on the c-fos gene activation is mediated by calcium influx as well as through protein kinase C.

• 약학회지
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• 제39권6호
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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 Nutrition and Health
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• 제44권3호
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• pp.196-202
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• 2011

본 연구는 EGCG의 항 당뇨 활성기전으로 췌장종양 선세포 AR42J의 분화 및 내분비기능 개선에 미치는 영향과 그 세포 신호전달 기전을 확인하였다. 그 결과 첫째, AR42J 세포에 EGCG 처리 시 췌장종양 선세포의 세포증식이 농도 의존적으로 감소되었다. 둘째, 세포사멸 유도가 유의적으로 일어나지 않는 농도인 1uM EGCG를 AR42J 세포에 처리한 결과 ngn 3, ${\alpha}$-amylase, insulin은 EGCG처리 24시간에 mRNA, 단백질 발현증가를 나타내었고 48시간에 유의적 증가를 나타내었다. 셋째, EGCG 처리 시 ERK, JNK MAP Kinase 기전은 인산화 억제를 나타내었고 반면에 p38 기전의 인산화는 48시간에 유의적 증가를 하였다. 넷째, p38기전 저해제인 SB203580을 처리하여 EGCG가 MAP Kinase 기전중의 하나인 p38 기전 인산화 활성의 회복을 나타내어 ngn 3 발현을 위한 전사 신호전달 기전임을 다시 확인하였다. 따라서 녹차 생리활성 성분인 EGCG의 췌장종양 선 세포 AR42J 처리 결과 EGCG는 p38 MAP Kinase 기전 활성을 통해 췌장 선세포의 분화지표인 ngn 3 발현을 증가시키며 췌장내분비 기능 지표인 ${\alpha}$-amylase, insulin 발현증가를 나타내어 세포의 내분비기능 개선에도 영향을 미치는 것으로 사료된다.

• 생명과학회지
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• 제32권11호
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• pp.882-889
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• 2022

Breast cancer anti-estrogen resistance 3 (BCAR3)는 유방암에서 항에스트로겐 내성을 유도하는 유전자들 중의 하나로 발견되었다. 우리는 이미 BCAR3가 c-jun, activator protein-1, serum response element의 promoter 등을 활성화하는 것을 보고하였다. 본 연구에서 우리는 정상 유방세포인 MCF-12A에서 estrogen response element (ERE) 활성에서의 BCAR3의 기능을 조사하였다. BCAR3의 발현이 ERE를 활성화하는 것을 발견하였다. 이 ERE 활성화는 17β-estradiol에 의해 더욱 증가하였고, 이는 항에스트론겐인 tamoxifen에 의해 억제되지 않았다. 다음으로 우리는 ERE 활성화를 이끄는 BCAR3의 신호전달 경로를 연구하였다. BCAR3에 의한 ERE 활성화는 phosphatidylinositol (PI) 3-kinase 경로 억제제인 LY294002와 AZD5363에 의해서는 억제되었으나, Mitogen-activated protein kinase 경로 억제제인 PD98059와 U0126에 의해서는 억제되지 않았다. ERE 활성화는 PI3-kinase의 catalytic subunit p110α와 Akt의 active mutant에 의해서는 유도되었고, 이 활성화는 추가적인 BCAR3에 의해서는 더욱 증가하지 않았다. 이러한 결과로부터 우리는 BCAR3가 PI3-kinase/Akt 신호전달경로를 통하여 ERE 활성화에 중요한 역할을 하는 것을 제시한다.

• Journal of Ginseng Research
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• 제39권3호
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• pp.279-285
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• 2015

Background: Korean Red Ginseng has been used as a traditional oriental medicine to treat illness and to promote health for several thousand years in Eastern Asia. It is widely accepted that ginseng saponins, ginsenosides, are the major active ingredients responsible for Korean Red Ginseng's therapeutic activity against many kinds of illness. Although the crude saponin fraction (CSF) displayed antiplatelet activity, the molecular mechanism of its action remains to be elucidated. Methods: The platelet aggregation was induced by collagen, the ligand of integrin ${\alpha}_{II}{\beta}_I$ and glycoprotein VI. The crude saponin's effects on granule secretion [e.g., calcium ion mobilization and adenosine triphosphate (ATP) release] were determined. The activation of mitogen-activated protein kinases (MAPKs), including extracellular signal-regulated protein kinase 1/2 (ERK1/2), c-Jun N-terminal kinases (JNKs), and p38 MAPK, and phosphoinositide 3-kinase (PI3K)/Akt was analyzed by immunoblotting. In addition, the activation of integrin ${\alpha}_{II}b{\beta}_{III}$ was examined by fluorocytometry. Results: CSF strongly inhibited collagen-induced platelet aggregation and ATP release in a concentration-dependent manner. It also markedly suppressed $[Ca^{2+}]_i$ mobilization in collagen-stimulated platelets. Immunoblotting assay revealed that CSF significantly suppressed ERK1/2, p38, JNK, PI3K, Akt, and mitogen-activated protein kinase kinase 1/2 phosphorylation. In addition, our fraction strongly inhibited the fibrinogen binding to integrin ${\alpha}_{IIb}{\beta}_3$. Conclusion: Our present data suggest that CSF may have a strong antiplatelet property and it can be considered as a candidate with therapeutic potential for the treatment of cardiovascular disorders involving abnormal platelet function.