• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 1998년도 학술발표회
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• pp.31-31
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• 1998

The role of a phosphoinositide-specific phospholipase C, PLC-deltal, in the bradykinin receptor-mediated signaling pathway was investigated using a clone of stably overexpressed PLC-deltal in rat pheochromocytoma (PC12) cells. Stimulation with bradykinin induced significantly higher [Ca$\^$2＋/]i rise in PLC-deltal-overexpressed cells (PC12-D1) than in the wild type (PC12-W) and the vector-transfected (PC12-V) cells.(omitted)

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1992년도 제1회 신약개발 연구발표회 초록집
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• pp.27-27
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• 1992

많은 홀몬, 성장인자 및 신경 전달물질들은 각각에 대한 세포막의 수용체와 결합하여 Phospholipase C (PLC)를 활성화시키므로서 신호를 세포내로 전달하여 세포의 성장, 대사, 신경 흥분, 수축 및 분비 등의 생리 현상을 나타내고 있다. 이 신호 전달의 중심 효소인 PLC는 현재까지의 효소 분리, 유전자 클로닝 등의 방법으로 3가지 Class에 적어도 8종유의 등위효소(Isozyme)들이 존재하고 있는 것으로 밝혀지고 있다. 본 연구에서는 이와 같은 등위효소에 특이적인 조절 물질을 선별할 수 있는 체계를 확립하기 위하여 새로운 동위효소의 분리 및 규명과 이 동위효소들에 대한 과발현 및 발현 세포주 개발을 추진하고 있다.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1993년도 제2회 신약개발 연구발표회 초록집
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• pp.63-63
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• 1993

Phospoinositide-specific phospholipase C (PLC)는 세포막의 phosphoinositide를 분해하여 inositol phosphates와 diacylglycerol을 전달하는데 핵심적인 효소이다. PLC는 분자량과 1차구조의 비교에 의하여 type (PLC-$\beta$, ${\gamma}$, $\delta$)로 구분되며, 각 type마다 2-4종의 subtype이 존재하고 PLC isozyme들에 대한 현재가지의 각종 신호 전달 및 조절에 대한 연구를 종합하면: (1) PLC-$\beta$ type은 G-protein과 연결되어 신호를 전달받고, (2) PLC-${\gamma}$ type은growth factor receptor tyrosine kinase에 의하여 인산화 되어 활성화됨으로, 세포의 성장 신호를 전달하며. (3) PLC-$\delta$ type에 대한 신호 전달이나 조절은 밝혀지지 않고 있다.

• The Korean Journal of Physiology and Pharmacology
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• 제1권1호
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• pp.19-25
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• 1997

The C-terminus ends of the second putative transmembrane domains of both $M_1$ and $M_2$ muscarinic receptors contain a triplet of amino acid residues consisting of leucine (L), tyrosine (Y) and threonine (T). This triplet is repeated as LYT-TYL in $M_1$ receptors at the interface between the second transmembrane domain and the first extracellular loop. Interestingly, however, it is repeated in a transposedfashion (LYT-LYT) in the sequence of $M_2$ receptors. In our previous work, we investigated the possible significance of this unique sequence diversity for determining the distinct differential receptor function at the two receptor subtypes. However, we found mutation of the LYTTYL sequence of $M_1$ receptors to the corresponding $M_2$ receptor LYTLYT sequence demonstrated markedly enhanced the stimulation of phosphoinositide (PI) hydrolysis by carbachol without a change in its coupling to increased cyclic AMP formation. In this work, thus, the enhanced stimulation of PI hydrolysis in the LYTLYT $M_1$ receptor mutant was further investigated. The stimulation of PI hydrolysis by carbachol was enhanced in the mutant $M_1$ receptor, and this change was not due to alterations in the rate of receptor desensitization or sequestration. The observed larger response to carbachol at mutant $M_1$ receptors was also not due to an artifact resulting from selection of CHO cells which express higher levels of G-proteins or phospholipase C. Our data suggest that although the LYTTYL sequence in $M_1$ muscarinic receptors is not involved in determining receptor pharmacology, mutation of the sequence enhanced the coupling of $M_1$ receptors to the stimulation of phospholipase C.

• 한국미생물·생명공학회지
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• 제24권1호
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• pp.19-26
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• 1996

A phospholipase C (PLC) inhibitor (MT267-2B) was isolated from the culture broth of actinomycetes isolate MT2617-2 by the extraction with n-butanol and column chromatographic techniques. The molecular weight of the inhibitor was 1057, by the spectroscopic analyses of IR, $^{13}C$-and $^{1}H$-NMR and ESI-MS. The chemical structure of MT2617-2B was found to be a macrolide compound consisted of a hemiketal ring, polyhydroxyl and polymethyl groups, which had a malonate and guanidine group as its side chain. MT2617-2B produced its two isomers having the same molecular weight by standing in methanol solution at room temperature. Therefore, MT2617-2B was identified as copiamycin and niphithricin A, macrolide antibiotics. The values of $IC_{50}$ against PLC-${\gamma}$1 and PLC-${\beta}$1 were 25 and 50${\mu}$g/ml, respectively. MT2617-2B had antimicrobial activities against Staphylococcus aureus and Candida albicans, but not against Escherichia coli.

• Archives of Pharmacal Research
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• 제21권4호
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• pp.423-428
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• 1998

The ligand binding signals to a wide variety of seven transmembrane cell surface receptors are transduced into intracellular signals through heterotrimeric G-proteins. Recently, there have been reports which show diverse coupling patterns of ligand-activated receptors to the members of Gq family $\alpha$ subunits. In order to shed some light on these complex signal processing networks, interactions between G$\alpha$q family of G protein and neurokinin-2 receptor as well as muscarinic M$_{1}$ receptor, which are considered to be new thearpeutic targets in asthma, were studied. Using washed membranes from Cos-7 cells co-transfected with different G.alpha.q and receptor cDNAs, the receptors were stimulated with various concentrations of carbachol and neurokinin A and the agonist-dependent release of [$^3H$]inositol phosphates through phospholipase C beta-1 activation was measured. Differential coupling of Gaq family of G-protein to muscarinic M$_{1}$ receptor and neurokinin-2 receptor was observed. The neurokinin-2 receptor shows a ligand-mediated response in membranes co-transfected with G$\alpha$q, G$\alpha$11 and G$\alpha$14 but not G$\alpha$16 and the ability of the muscarinic $M_1$ receptor to activate phospholipase C through G$\alpha$/11 but not G$\alpha$14 and G$\alpha$16 was demonstrated. Clearly G$\alpha$/11 can couple $\M_1$ and neurokinin-2 receptor to activate phospholipase C. But, there are differences in the relative coupling of the G$\alpha$14 and G$\alpha$16 subunits to these receptors.

• Applied Biological Chemistry
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• 제46권3호
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• pp.251-256
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• 2003

한국산 인삼을 60% acetone으로 추출하여 Sepadex LH-20 gel column chromatography, MCI-CHP 20 gel column chromatography, ${\mu}-Bondapack\;C_{18}$ gel column chromatography을 이용하여 polyphenol 분획물을 3종류를 분리하여 항산화 효과, phospholipase $A_2$ 저해효과 및 암세포 증식억제 효과를 검토하였다. 항산화 효과에서 분획물 I은 150 ppm에서 $Cu^{2+},\;KO_2$ 그리고 $H_2O_2$에 대하여 각각 48.16%, 79.71%, 43.55%를 나타내었고 DPPH 수소공여능은 분획물 II가 200 ppm에서 35.17%의 라디칼소거능을 보였다. 분획물 III는 $Fe^{2+}$, OH가 존재 시 150 ppm에서 48.49%, 25%의 항산화효과를 나타내었다. Phospholipase $A_2$ 저해활성은 분획물 III이 $60\;{\mu}/ml$에서 48.9%의 활성을 나타냈다. HT 29 cell에 대한 인삼의 세포 독성은 분획물 II에서 0.25 mg/ml에서 73.29%의 가장 높은 억제능을 나타내었다.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.84.1-84
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• 2003

Magnaporthe grisea, the casual agent of rice blast, forms an appressorium to penetrate its host. Much has been learned about environmental cues and signal transduction pathways, especially those involving CAMP and MAP kinases, on appressorium formation during the last decade. More recently, pharmacological data suggest that calcium/calmodulin-dependent signaling system is involved in its appressorium formation. To determine the role of phosphoinositide-specific phospholipase C (PI-PLC) on appressorium formation, a gene (WPLCl) encoding PI-PLC was cloned and characterized from M. grisea strain 70-15. Sequence analysis showed that MPLCl has alt five conserved domains present in other phospholipase C genes from several filamentous fungi and mammals. Null mutants (mplcl) generated by targeted gene disruption exhibited pleiotropic effects on conidial morphology, appressorium formation, fertility and pathogenicity. mplcl mutants developed nonfunctional appressoria and are also defective in infectious growth in host tissues. Defects in appressorium formation and pathogenicity in mplcl mutants were complemented by a mouse PLCdelta-1 cDNA under the control of the MPLCl promoter. These results suggest that cellular signaling mediated by MPLCl plays crucial and diverse roles in development and pathogenicity of M. grisea, and functional conservation between fungal and mammalian Pl-PLCs.

• 약학회지
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• 제41권4호
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• pp.433-438
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• 1997

MT 51005 as a potent inhibitor of phospholipase C(PLC) was purified from the culture broth of a fungal strain No. 51005 isolated from soil. It was identified as a benzaldehyde d erivative, anguillosporal. by the physico-chemical properties and spectroscopic data. Anguillosporal showed the inhibitory activity against purified PLC with an $IC_{50}\;of\;13{\mu}g/ml$. And it also inhibited the formation of inositol phosphates($IP_t$) in platelet-derived growth factor(PDGF)-stimulated $NIH3T3{\gamma}1$ cells with an $IC_{50}\;of\;0.8{\mu}g/ml$.

• 약학회지
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• 제59권4호
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• pp.158-163
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• 2015

Cardiac myocytes are subjected to fluid shear stress during each contraction and relaxation. Under pathological conditions, such as valve disease, heart failure or hypertension, shear stress in cardiac chamber increases due to high blood volume and pressure. The shear stress induces proarrhythmic longitudinal global $Ca^{2+}$ waves in atrial myocytes. In the present study, we further explored underlying cellular mechanism for the shear stress-induced longitudinal global $Ca^{2+}$ wave in isolated rat atrial myocytes. A shear stress of ${\sim}16dyn/cm^2$ was applied onto entire single myocyte using pressurized fluid puffing. Confocal $Ca^{2+}$ imaging was performed to measure local and global $Ca^{2+}$ signals. Shear stress elicited longitudinally propagating global $Ca^{2+}$ wave (${\sim}80{\mu}m/s$). The occurrence of shear stress-induced atrial $Ca^{2+}$ wave was eliminated by the inhibition of ryanodine receptors (RyRs) or inositol 1,4,5-trisphosphate receptors ($IP_3Rs$). In addition, pretreatment of phospholipase C (PLC) inhibitor U73122, but not its inactive analogue U73343, abolished the generation of longitudinal $Ca^{2+}$ wave under shear stress. Our data suggest that shear-induced longitudinal $Ca^{2+}$ wave may be induced by $Ca^{2+}$-induced $Ca^{2+}$ release through the RyRs which is triggered by $PLC-IP_3R$ signaling in atrial myocytes.