• 제목/요약/키워드: Small G protein

검색결과 401건 처리시간 0.027초

The Mechanism of Action of Ghrelin and Motilin in the Pacemaker Potentials of Interstitial Cells of Cajal from the Murine Small Intestine

  • Kim, Jeong Nam;Kim, Byung Joo
    • Molecules and Cells
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    • 제42권6호
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    • pp.470-479
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    • 2019
  • Interstitial cells of Cajal (ICCs) are pacemaker cells that exhibit periodic spontaneous depolarization in the gastrointestinal (GI) tract and generate pacemaker potentials. In this study, we investigated the effects of ghrelin and motilin on the pacemaker potentials of ICCs isolated from the mouse small intestine. Using the whole-cell patch-clamp configuration, we demonstrated that ghrelin depolarized pacemaker potentials of cultured ICCs in a dose-dependent manner. The ghrelin receptor antagonist [D-Lys] GHRP-6 completely inhibited this ghrelin-induced depolarization. Intracellular guanosine 5'-diphosphate-${\beta}$-S and pre-treatment with $Ca^{2+}$-free solution or thapsigargin also blocked the ghrelin-induced depolarization. To investigate the involvement of inositol triphosphate ($IP_3$), Rho kinase, and protein kinase C (PKC) in ghrelin-mediated pacemaker potential depolarization of ICCs, we used the $IP_3$ receptor inhibitors 2-aminoethoxydiphenyl borate and xestospongin C, the Rho kinase inhibitor Y-27632, and the PKC inhibitors staurosporine, Go6976, and rottlerin. All inhibitors except rottlerin blocked the ghrelin-induced pacemaker potential depolarization of ICCs. In addition, motilin depolarized the pacemaker potentials of ICCs in a similar dose-dependent manner as ghrelin, and this was also completely inhibited by [D-Lys] GHRP-6. These results suggest that ghrelin induced the pacemaker potential depolarization through the ghrelin receptor in a G protein-, $IP_3$-, Rho kinase-, and PKC-dependent manner via intracellular and extracellular $Ca^{2+}$ regulation. In addition, motilin was able to depolarize the pacemaker potentials of ICCs through the ghrelin receptor. Therefore, ghrelin and its receptor may modulate GI motility by acting on ICCs in the murine small intestine.

정선산 쥐눈이콩의 부위별 이화학적 특성 및 항산화 효과 (Antioxidative Activity and Chemical Characteristics from Different Organs of Small Black Soybean (Yak-Kong) Grown in the Area of Jungsun)

  • 사재훈;신인철;정경진;심태흠;오흥석;김영진;정의호;김광기;최대성
    • 한국식품과학회지
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    • 제35권2호
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    • pp.309-315
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    • 2003
  • 이상의 결과를 종합해 볼 때, 쥐눈이콩은 조단백 및 조지방의 함량이 높고, 무기질이 풍부하며, 불포화지방산이 풍부하고 linoleic acid가 다량 함유되어 있었다. Glucose와 galactose가 주요 구성당이었으며, 12종의 지방산이 동정되었다. 쥐눈이콩 추출물의 항산화 활성을 탐색한 결과 종피 메탄올 추출물$(IC_{50}:\; 8.3\;{\mu}g/ml)$과 종피 75% 에탄올 추출물$(IC_{50}: 10.0{\mu}g/ml)$이 높은 항산화 활성을 나타내었다. 항산화 활성이 가장 높은 쥐눈이콩 종피 추출물을 용매분획하여 각 분획물에 대한 생리활성을 조사한 결과 에틸아세테이트 분획물에서 주된 활성이 나타났으며 페놀성화합물의 경우 100 g당 13.53 g으로 매우 높은 함량을 지니고 있었다. 쥐눈이콩의 생리활성 탐색결과 종피 부위에 다량의 페놀성 화합물을 함유하고 있으며 항산화 활성이 가장 높은 부위임을 규명하였다.

Expression of Bacillus macerans Cyclodextrin Glucanotransferase on the Cell Surface of Saccharomyces cerevisiae.

  • 김규용;김명동;한남수;서진호
    • 한국생물공학회:학술대회논문집
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    • 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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    • pp.191-193
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    • 2000
  • B. macerans 유래의 CGTase를 yeast surface display기술을 이용하여 S. cerevisiae의 표면에 발현된 것을 halo-test와 immunofluorescence microscopy와 flow cytometry를 통하여 확인하였다. 재조합 효모는 효소의 cyclization작용을 저해하고 CD의 분해작용을 촉진하는 glucose와 maltose를 제거하는 발효공정과 표면 발현된 CGTase의 cyclization 공정을 동시에 수행할 수 있어 CD의 생산, 분리공정을 효율적으로 개선하였다.

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Biosynthesis of 3-Hydroxy-5-Methyl-O-Methyltyrosine in the Saframycin/Safracin Biosynthetic Pathway

  • Fu, Cheng-Yu;Tang, Man-Cheng;Peng, Chao;Li, Lei;He, Yan-Ling;Liu, Wen;Tang, Gong-Li
    • Journal of Microbiology and Biotechnology
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    • 제19권5호
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    • pp.439-446
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    • 2009
  • The biosynthesis study of antibiotics saframycin (SFM) in Streptomyces lavendulae and safracin (SAC) in Pseudomonas fluorescens demonstrated that 3-hydroxy-S-methyl-O-methyltyrosine (3hSmOmTyr), a nonproteinogenic amino acid, is the precursor of the tetrahydroisoquinoline molecular core. In the biosynthetic gene cluster of SAC/SFM, sacD/sfmD encodes a protein with high homology to each other but no sequence similarity to other known enzymes; sacF/sfmM2 and sacG/sfmM3 encode methyltransferases for C-methylation and O-methylation; and sacE/sfinF encodes a small protein with significant sequence similarity to the MbtH-like proteins, which are frequently found in the biosynthetic pathways of non ribosomal peptide antibiotics and siderophores. To address their function, the biosynthetic cassette of 3h5mOmTyr was heterologously expressed in S. coelicolor and P. putida, and an in-frame deletion and complementation in trans were carried out. The results revealed that (i) SfmD catalyzes the hydroxylation of aromatic rings; (ii) sacD/sacF/sacG in the SAC gene cluster and sfmD/sfmM2/sfmM3 in the SFM cluster are sufficient for the biosynthesis of 3h5mOmTyr; and (iii) the mbtH-like gene is not required for the biosynthesis of the 3h5mOmTyr precursor.

WASP 유전자의 Exon 2에서 새로운 돌연변이를 가진 Wiskott-Aldrich 증후군의 1례 (A Case of Wiskott-Aldrich Syndrome with Novel Mutation in Exon 2 of the WASP Gene)

  • 이혁;박정인;김선영;문경희;이호근;황평한
    • Clinical and Experimental Pediatrics
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    • 제48권5호
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    • pp.551-556
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    • 2005
  • 저자들은 혈소판 평균용적 및 혈소판 수의 감소, 심한 아토피 피부염 및 반복 감염을 임상적 증상으로 추정 진단된 WAS 환아로부터 WAS의 확진에 필수적인 분자학적 분석을 실시하여 WASP 단백질의 발현이 감소되어 있으며, WASP 유전자의 Exon 2, 번역 개시점으로부터 208번째의 염기서열 구아닌(g)이 아데닌(a)으로 변이되어 70번째 아미노산인 글라이신(Gly)이 알지닌(Arg)으로 변화된 missense 변이(G70A)를 발견하여 확진된 WAS 환자를 경험하였기에 문헌 고찰과 함께 이를 보고하는 바이다.

siRNA Silencing EZH2 Reverses Cisplatin-resistance of Human Non-small Cell Lung and Gastric Cancer Cells

  • Zhou, Wen;Wang, Jian;Man, Wang-Ying;Zhang, Qing-Wei;Xu, Wen-Gui
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권6호
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    • pp.2425-2430
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    • 2015
  • Clinical resistance to chemotherapeutic agents is one of the major hindrances in the treatment of human cancers. EHZ2 is involved in drug resistance and is overexpressed in drug-resistant cancer cell lines. In this study, we investigated the effects of EHZ2 on cisplatin -resistance in A549/DDP and AGS/DDP cells. EHZ2 mRNA and protein were found to be significantly overexpressed in A549/DDP and AGS/DDP cells, compared to parental cells. EHZ2 siRNA successfully silenced EHZ2 mRNA and protein expression. Proliferation was inhibited and drug resistance to cisplatin was improved. Flow cytometry showed that silencing of EHZ2 arrested A549/DDP and AGS/DDP cells in the G0/G1 phase, increasing apoptosis, rh-123 fluorescence intensity and caspase-3/8 activities. Silencing of EHZ2 also significantly reduced the mRNA and protein expression levels of cyclin D1 and MDR1,while up-regulating p15, p21, p27 and miR-218 in A549/DPP cells. Furthermore, silencing of EHZ2 also significantly increased the expression level of tumor suppressor factor miR-218. We also found down-regulating EHZ2 expression increased methylation in A549/DDP and AGS/DDP cells. This study demonstrates that drug resistance can be effectively reversed in human cisplatin-resistant lung and gastric cancer cells through delivery of siRNAs targeting EHZ2.

Induction of Pacemaker Currents by DA-9701, a Prokinetic Agent, in Interstitial Cells of Cajal from Murine Small Intestine

  • Choi, Seok;Choi, Jeong June;Jun, Jae Yeoul;Koh, Jae Woong;Kim, Sang Hun;Kim, Dong Hee;Pyo, Myoung-Yun;Choi, Sangzin;Son, Jin Pub;Lee, Inki;Son, Miwon;Jin, Mirim
    • Molecules and Cells
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    • 제27권3호
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    • pp.307-312
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    • 2009
  • The interstitial cells of Cajal (ICC) are pacemaking cells required for gastrointestinal motility. The possibility of whether DA-9701, a novel prokinetic agent formulated with Pharbitis Semen and Corydalis Tuber, modulates pacemaker activities in the ICC was tested using the whole cell patch clamp technique. DA-9701 produced membrane depolarization and increased tonic inward pacemaker currents in the voltage-clamp mode. The application of flufenamic acid, a non-selective cation channel blocker, but not niflumic acid, abolished the generation of pacemaker currents induced by DA-9701. Pretreatment with a $Ca^{2+}$-free solution and thapsigargin, a $Ca^{2+}$-ATPase inhibitor in the endoplasmic reticulum, abolished the generation of pacemaker currents. In addition, the tonic inward currents were inhibited by U-73122, an active phospholipase C inhibitor, but not by $GDP-{\beta}-S$, which permanently binds G-binding proteins. Furthermore, the protein kinase C inhibitors, chelerythrine and calphostin C, did not block the DA-9701-induced pacemaker currents. These results suggest that DA-9701 might affect gastrointestinal motility by the modulation of pacemaker activity in the ICC, and the activation is associated with the non-selective cationic channels via external $Ca^{2+}$ influx, phospholipase C activation, and $Ca^{2+}$ release from internal storage in a G protein-independent and protein kinase C-independent manner.

시중에 유통되는 콩의 종류에 따른 품질 특성 (Quality Characteristics of Various Beans in Distribution)

  • 문혜경;이수원;문재남;김동환;윤원중;김귀영
    • 동아시아식생활학회지
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    • 제21권2호
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    • pp.215-221
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    • 2011
  • 콩의 일반성분 분석에서 조지방은 백태 17.60${\pm}$0.14%, 조단백질은 서목태 42.38${\pm}$0.15%로 가장 높고, 조회분의 경우 비슷한 값을 나타내었다. 색도는 L값 작두콩 64.07${\pm}$0.97, a값 강낭콩 15.64${\pm}$0.48, b값 백태 22.92${\pm}$0.09로 각각 가장 높은값을 나타내었다. 유리당 중 fructose, glucose, maltose는 서목태가 각각 13.92 mg/g, 20.52 mg/g, 2.61 mg/g으로 가장 높은 함유량을 보였으며, sucrose는 서리태가 54.23 mg/g으로 가장 높은 함유량을 보였다. 유기산 중 oxalic acid, malic acid, tartaric acid는 각각 서목태가 23.26 mg/100 g, 18.24 mg/100g, 23.6 mg/100 g으로 가장 높은 함유량을 보였으며, citric acid의 경우 청태가 7.22 mg/100 g으로 가장 높은 함유량을 보였다. 콩의 종류에 따라 각각 함유 성분에 차이가 있었다. 구성아미노산은 glutamic acid가 2.68~6.18 g/100 g으로 가장 많이 함유하고 있으며, 그 중 서리태가 가장 많이 함유하고 있는 것으로 나타났다. 콩의 무기질은 K, Mg이 가장 많이 함유되어 있고, Co, Cu, Zn은 미량 함유되어 있는 것으로 나타났다. 이상의 결과에서 콩의 품종에 따른 차이와 동일한 품종일지라도 재배 및 환경 요인, 건조 방법, 건조 상태에 따라 많은 영향을 받는 것으로 생각된다.

Induction of Apoptosis by Ethyl Acetate Fraction of Astragalus membranaceus in Human Non-small Cell Lung Cancer Cells - Apoptosis Induction by Astragalus membranaceus -

  • Park, Hyun-Ji;Park, Shin-Hyung
    • 대한약침학회지
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    • 제21권4호
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    • pp.268-276
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    • 2018
  • Objectives: The purpose of this study is to investigate the anti-cancer effects of different fractions of Astragalus membranaceus (AM) in human non-small cell lung cancer (NSCLC) cells. Methods: We isolated hexane, ethyl acetate, and butanol fractions from crude ethanol extract of AM. The cell death was examined by MTT assay and trypan blue exclusion assay. Apoptosis was detected by DAPI staining, annexin V-PI double staining and cell cycle analysis. The expression of apoptosis-related proteins and mitogen-activated protein kinases (MAPKs) was examined by western blot. Results: Among various fractions of AM, the ethyl acetate fraction of AM (EAM) showed the strongest cytotoxic effect in NSCLC cells. EAM reduced the cell proliferation in a time- and dose-dependent manner in NSCLC cells. In addition, EAM induced the chromatin condensation, and increased the population of sub-G1 phase and annexin V-positive cells in a time-dependent manner, indicating that EAM induced apoptosis in NSCLC cells. Consistently, EAM enhanced the expression of cleaved caspase-8 and -9, and induced the accumulation of cleaved- poly (ADP-ribose) polymerase (PARP). Among MAPK proteins, only ERK was dephosphorylated by EAM, suggesting that ERK might be related with EAM-induced apoptosis. Conclusion: Our results clearly demonstrate that EAM exhibited anti-cancer effects in NSCLC cells by induction of apoptosis. We provide a valuable evidence which suggests that AM could be a desirable therapeutic option for treatment of NSCLC.

농촌(農村) 식품섭취실태(食品攝取實態) 및 영양조사(營養調査) (Food Consumption and Nutrition Survey in Korean Rural Areas)

  • 박양자;전승규
    • Journal of Nutrition and Health
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    • 제9권2호
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    • pp.87-97
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    • 1976
  • This study is based on data from the food consumption survey on 727 members of 125 farm households from 7 different provinces. The survey was conducted in May, 1975 in cooperation with the O.R.D. The results obtained in this study are summarized as follows. 1. The average consumption of the basic food groups per capita per day was 563 g for cereals and grains(398g of rice and 129g of barley), 87.6g for meats and legumes, 317.8g for fruits and vegetables, 25.7g for milks and small fishes, 9.1g for fats and oils, and 45.1g for other group. 2. The average daily consumption of calories and nutrients was 2256 cal and 11.7g for animal proteins, 70.5g for total proteins, 21.6g for fats, 537.4mg for calcium, 18.1mg for iron, 5375lU for vitamin A, 1.27mg for thiamine, 1.05mg for riboflavin, 15.5mg for niacin, 77.7mg for ascorbic acid. When these figures are compared with the recommended allowances for Korean, the calories and nutrients intakes were satisfactory, except for the intakes of animal protein which was below two third of the recommended allowance. 3. The diets of the projected villages differed from those of the non-projected villages in the following respect: (a) The amounts of animal proteins and fats were larger in the projected villages than in the non-projected villages. (b) The percentage contribution of fats to the total amount of calories from three nutrients, carbohydrates, proteins and fats was higher in the projected villages than in tile non-projected villages. (c) The percentage contribution from carbohydrates to the total amount of calories was higher in the non-projected villages than in the projected villages. 4. Certain physical and clinical symptoms were observed among the people in the rural areas, which can be related to the shortages of animal proteins and fats in their diets. It is recommended to pay special attention to the nutrition of school children in the Korean rural areas.

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