• 제목/요약/키워드: i-motif

검색결과 150건 처리시간 0.026초

Ginseng Gintonin Activates the Human Cardiac Delayed Rectifier K+ Channel: Involvement of Ca2+/Calmodulin Binding Sites

  • Choi, Sun-Hye;Lee, Byung-Hwan;Kim, Hyeon-Joong;Jung, Seok-Won;Kim, Hyun-Sook;Shin, Ho-Chul;Lee, Jun-Hee;Kim, Hyoung-Chun;Rhim, Hyewhon;Hwang, Sung-Hee;Ha, Tal Soo;Kim, Hyun-Ji;Cho, Hana;Nah, Seung-Yeol
    • Molecules and Cells
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    • 제37권9호
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    • pp.656-663
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    • 2014
  • Gintonin, a novel, ginseng-derived G protein-coupled lysophosphatidic acid (LPA) receptor ligand, elicits $[Ca^{2+}]_i$ transients in neuronal and non-neuronal cells via pertussis toxin-sensitive and pertussis toxin-insensitive G proteins. The slowly activating delayed rectifier $K^+$ ($I_{Ks}$) channel is a cardiac $K^+$ channel composed of KCNQ1 and KCNE1 subunits. The C terminus of the KCNQ1 channel protein has two calmodulin-binding sites that are involved in regulating $I_{Ks}$ channels. In this study, we investigated the molecular mechanisms of gintonin-mediated activation of human $I_{Ks}$ channel activity by expressing human $I_{Ks}$ channels in Xenopus oocytes. We found that gintonin enhances $I_{Ks}$ channel currents in concentration- and voltage-dependent manners. The $EC_{50}$ for the $I_{Ks}$ channel was $0.05{\pm}0.01{\mu}g/ml$. Gintonin-mediated activation 1 of the $I_{Ks}$ channels was blocked by an LPA1/3 receptor antagonist, an active phospholipase C inhibitor, an $IP_3$ receptor antagonist, and the calcium chelator BAPTA. Gintonin-mediated activation of both the $I_{Ks}$ channel was also blocked by the calmodulin (CaM) blocker calmidazolium. Mutations in the KCNQ1 $[Ca^{2+}]_i$/CaM-binding IQ motif sites (S373P, W392R, or R539W)blocked the action of gintonin on $I_{Ks}$ channel. However, gintonin had no effect on hERG $K^+$ channel activity. These results show that gintonin-mediated enhancement of $I_{Ks}$ channel currents is achieved through binding of the $[Ca^{2+}]_i$/CaM complex to the C terminus of KCNQ1 subunit.

NMR Studies on the Structure of Human Annexin I

  • Han, Hee-Yong;Bang, Keun-Su;Na, Doe-Sun;Lee, Bong-Jin
    • 한국응용약물학회:학술대회논문집
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    • 한국응용약물학회 1996년도 춘계학술대회
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    • pp.182-182
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    • 1996
  • Annexin I is a member of the annexin family of calcium dependent phospholipid binding proteins and has anti-inflammatory activity by inhibiting phospholipase A$_2$ (PLA$_2$). Recent X-ray crystallographic study of annexin I identified six Ca$\^$2+/ binding bites, which was different types (type II, III) from the well-known EF-hand motif (type I). In this work, the structure of annexin I was studied at atomic level by using $^1$H, $\^$15/N and $\^$l3/C NMR(nuclear magnetic resonance) spectroscopy, and the effect of Ca$\^$2+/ binding on the structure of annexin I was studied, and compared with that of Mg$\^$2+/ binding, When Ca$\^$2+/ was added to annexin I, NMR peak change was occured in high- and low-field regions of $^1$H-NMR spectra. NMR peak change by Ca$\^$2+/ binding was different from that by Mg$\^$2+/ binding. Because annexin I is a larger protein with 35 kDa molecular weight, site-specific (amide-$\^$15/N, carbonyl-$\^$l3/C) labeling technique was also used. We were able to detect methionine, tyrosine and phenylalanine peaks respectively in $\^$13/C-NMR spectra, and each residue was able to be assigned by the method of doubly labeling annexin I with [$\^$13/C] carbonyl-amino acid and [$\^$15/N] amide-amino acid. In $\^$l3/C-NMR spectra of [$\^$13/C] carbonyl-Met labeled annexin I, we observed that methionine residues spatially located near Ca$\^$2+/ binding Sites Were Significantly effected by Ca$\^$2+/ binding. From UV spectroscopic data on the effect of Ca$\^$2+/ binding, we knew that Ca$\^$2+/ binding sites of annexin I have cooperativity in Ca$\^$2+/ binding. The interaction of annexin I with PLA$_2$ also could be detected by using heteronuclear NMR spctroscopy. Consequently, we expect that the anti-inflammatory action mechanism of annexin I may be a specific protein-protein interaction. The residues involved in the interaction with PLA$_2$ can be identified as active site by assigning NMR peaks effected by PLA$_2$ binding.

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Molecular cloning and expression analysis of an interferon stimulated gene 15 from rock bream Oplegnathus fasciatus

  • Kim, Ju-Won;Kwon, Mun-Gyeong;Park, Myoung-Ae;Hwang, Jee-Youn;Park, Hyung-Jun;Baeck, Gun-Wook;Kim, Mu-Chan;Park, Chan-Il
    • 한국어병학회지
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    • 제23권2호
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    • pp.177-187
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    • 2010
  • The Interferon stimulated gene 15 (ISG15) is strongly induced in many cell types by IFNs, viral infections, and double-stranded RNA (poly I:C). The ISG15 homologue cDNA was isolated from the rock bream LPS stimulated leukocyte cDNA library. The rock bream ISG15 homologue was found to consist of 833 bp encoding 157 amino acid residues. Compared with other known ISG15 peptide sequences, the most conserved regions of the rock bream ISG15 peptide were found to be the tandem ubiquitin-like domains and a C-terminal LRLRGG conjugating motif, characteristic of mammalian and non-mammalian ISG15 proteins. Phylogenetic analysis based on the deduced amino acid sequence revealed a homologous relationship between the ISG15 sequence of rock bream and that of Atlantic salmon, Atlantic cod, northern snake head, black rockfish and olive flounder. The expression of the rock bream ISG15 molecule was induced in the peripheral blood leukocytes (PBLs) from 1 to 24 h following poly I:C stimulation, with a peak at 3 h post-stimulation. The rock bream ISG15 gene was predominantly expressed in the PBLs, spleen and gill.

Saccharopolyspora erythraea IFO 13426으로부터 Autoregulator Receptor Protein Gene의 Cloning (Cloning of Autoregulator Receptor Gene form Saccharopolyspora erythraea IFO 13426)

  • 김현수;이경화;조재만
    • 한국미생물·생명공학회지
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    • 제31권2호
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    • pp.117-123
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    • 2003
  • 공시균인 Saccha. erythraea IFO 13426으로부터 VB-C에 의한 erythromycin 생산 유도능이 시사된 바 있으므로, 공시균으로부터 VB-C와 특이적으로 결합하는 autoregulators 및 receptor gene을 탐색하여, EM의 생산 조절 기구를 규명하고자 하였다. 탐색의 일환으로 기존의 Streptomyce속 receptor gene의 공통배열을 primer로 이용하여 PCR을 수행하였고, 예상 크기인 120bp의 단편을 pUC19 vector에 ligation하여 E. coli DH5$\alpha$에 형질전환한 후, plasmid를 분리하여 BamHI을 처리하여 2% agarose gel에 전기영동한 결과, pUC19 (2.7kbp)외에 receptor gene PCR 산물이 120bp위치에 존재하는 것을 확인하였다. 형질전환된 plasmid로 PCR을 수행하여 염기배열을 결정한 후 해석한 결과 Streptomyces sp. 유래의 receptor gene과 유사함을 확인하였다. 따라서 Saccha. erythraea IFO 13426에는 항생물질인 erythromycin의 생산에 관여한다고 추정되는 autoregulator receptor protein을 코드하는 유전자가 존재할 것으로 예상되어 120 bp의 PCR product를 probe로 이용하여 Southern 및 colony hybridization을 통하여 3.2 kbp의 SacI 단편을 가지는 plasmid(pESG)를 제작하였고, 이를 sequencing한 결과, autoregulator receptor protein 유전자가 KpnI과 SalI을 포함하는 영역에 존재한다는 것을 알 수 있었으며 이를 EsgR이라 명명하였다. 유전자 해석 결과, EsgR은 205개의 아미노산으로 구성되어 있으며, 이는 기존의 autoregulator receptor proteins과 비교시 30%이상의 상동성을 나타내었으며, 기존의 autoregulator receptor prorein들이 하부의 항생물질 생합성 유전자들의 제어를 위해 보유하고 있는 helix-turn-helix DNA binding motif를 EsgR이 보유하고 있는 점에서, EsgR은 Saccha. erythraea가 보유하는 autoregulator receptor protein을 code하는 유전자로 추정되었다.

Characterization of Korean Cattle Keratin IV Gene

  • Kim, D.Y.;Yu, S.L.;Sang, B.C.;Yu, D.Y.
    • Asian-Australasian Journal of Animal Sciences
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    • 제16권7호
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    • pp.1055-1059
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    • 2003
  • Keratins, the constituents of epithelial intermediate filaments, are precisely regulated in a tissue and development specific manner. There are two types of keratin in bovine. The type I is acidic keratin and the type II is neutral/basic keratin. 1.5 kb of 5' flanking sequence of Korean cattle Keratin IV gene, type II keratin (59 kDa), was cloned and sequenced. A symmetrical motif AApuCCAAA are located in a defined region upstream of the TATA box. Proximal SP1, AP1, E-box and CACC elements as the major determinants of transcription are identified. When it was compared to the bovine sequence from -600 bp to ATG upstream, the homology was 97% in nucleotide sequence. Several A and T sequences, located in the promoter region, are deleted in the Korean cattle. An expression vector consisted of Korean cattle Keratin IV gene promoter/SV40 large T antigen was transfected to HaCaT cell (Epithelial keratinocyte). The transformed HaCaT cells showed active proliferation when treated with PDGF (Platelet-derived growth factor) in 0.3% soft agar compared to control cells. These results indicate that Korean cattle Keratin IVgene promoter can be used as a promoter for transfection into epithelial cell.

Thermodynamic Analyses of the Constitutive Splicing Pathway for Ovomucoid Pre-mRNA

  • Ro-Choi, Tae Suk;Choi, Yong Chun
    • Molecules and Cells
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    • 제27권6호
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    • pp.657-665
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    • 2009
  • The ovomucoid pre-mRNA has been folded into mini-hairpins adaptable for the RNA recognition motif (RRM) protein binding. The number of mini-hairpins were 372 for pre-mRNA and 83-86 for mature mRNA. The spatial arrangements are, in average, 16 nucleotides per mini-hairpin which includes 7 nt in the stem, 5.6 nt in the loop and 3.7 nt in the inter-hairpin spacer. The constitutive splicing system of ovomucoid-pre-mRNA is characterized by preferred order of intron removal of 5/6 > 7/4 > 2/1 > 3. The 5' splice sites (5'SS), branch point sequences (BPS) and 3' splice sites (3'SS) were identified and free energies involved have been estimated in 7 splice sites. Thermodynamic barriers for splice sites from the least (|lowest| -Kcal) were 5, 4, 7, 6, 2, 1, and 3; i.e., -18.7 Kcal, -20.2 Kcal, -21.0 Kcal, -24.0 Kcal, - 25.4 Kcal, -26.4 Kcal and -28.2 Kcal respectively. These are parallel to the kinetic data of splicing order reported in the literature. As a result, the preferred order of intron removals can be described by a consideration of free energy changes involved in the spliceosomal assembly pathway. This finding is consistent with the validity of hnRNP formation mechanisms in previous reports.

자비에돌란 영화의 포스트 모더니즘 <아이킬드마이마더, 마미를 중심으로> (Post Modernism in Xavier Dolan's Movies -With a Focus on "I Killed My Mother(2009)" and "Mommy(2014)"-)

  • 김로유
    • 한국콘텐츠학회논문지
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    • 제16권3호
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    • pp.162-170
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    • 2016
  • 자비에 돌란의 모성과 성적(性的) 정체성에 천착하는 작품들의 영화적 시도와 실험은 어렵거나 낯설지만은 않다. 기존 영화의 양식과 형식을 해체하거나 파괴하기보다는 우리가 기억 하는 친숙한 영화나 시, 패션, 음악, 미술 등의 상호텍스트성 기법인 패스티시와 자기반영성을 통해 소통하고 있기 때문이다. 또한, 그는 작품에서 거듭 반복되는 포스트모더니즘의 특징들이라 할 수 있는 탈(脫) 장르, 탈 주체, 대중문화에 대한 관심, 과거에 대한 향수의 재현으로 말을 건넨다. 본 연구에서는 일종의 유행처럼 지나갔다고 여겨진 포스트모더니즘의 현재를 재인식하고자 하고 자비에 돌란의 영화의 포스트 모더니즘적 특징과 반복적으로 사용된 모티프를 분석하고자 한다. 또한, 그의 작품에서 등장하는 인물들을 통해 소수자들에 대한 감독의 관심과 알레고리적 분석을 시도하고자 한다.

Cloning and characterization of ADP-ribosylation factor 1b from the olive flounder Paralichthys olivaceus

  • Son, So-Hee;Jang, Jin-Hyeon;Jo, Hyeon-Kyeong;Chung, Joon-Ki;Lee, Hyung-Ho
    • Fisheries and Aquatic Sciences
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    • 제20권6호
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    • pp.10.1-10.7
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    • 2017
  • Small GTPases are well known as one of the signal transduction factors of immune systems. The ADP-ribosylation factors (ARFs) can be classified into three groups based on the peptide sequence, protein molecular weight, gene structure, and phylogenetic analysis. ARF1 recruits coat proteins to the Golgi membranes when it is bound to GTP. The class I duplicated ARF gene was cloned and characterized from the olive flounder (Paralichthys olivaceus) for this study. PoARF1b contains the GTP-binding motif and the switch 1 and 2 regions. PoARF1b and PoARF1b mutants were transfected into a Hirame natural embryo cell to determine the distribution of its GDP/GTP-bound state; consequently, it was confirmed that PoARF1b associates with the Golgi body when it is in a GTP-binding form. The results of the qPCR-described PoARF1b were expressed for all of the P. olivaceus tissues. The authors plan to study the gene expression patterns of PoARF1b in terms of immunity challenges.

CIM 구축을 위한 지능형 고장진단 시스템 개발 (Development of Intelligent Fault Diagnosis System for CIM)

  • 배용환;오상엽
    • 한국산업융합학회 논문집
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    • 제7권2호
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    • pp.199-205
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    • 2004
  • This paper describes the fault diagnosis method to order to construct CIM in complex system with hierarchical structure similar to human body structure. Complex system is divided into unit, item and component. For diagnosing this hierarchical complex system, it is necessary to implement a special neural network. Fault diagnosis system can forecast faults in a system and decide from the signal information of current machine state. Comparing with other diagnosis system for a single fault, the developed system deals with multiple fault diagnosis, comprising hierarchical neural network (HNN). HNN consists of four level neural network, i.e. first is fault symptom classification and second fault diagnosis for item, third is symptom classification and forth fault diagnosis for component. UNIX IPC is used for implementing HNN with multitasking and message transfer between processes in SUN workstation with X-Windows (Motif). We tested HNN at four units, seven items per unit, seven components per item in a complex system. Each one neural network represents a separate process in UNIX operating system, information exchanging and cooperating between each neural network was done by message queue.

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Isolation and characterization of a noval membrane-bound cytochrome $C_{553}$ from the strictly anaerobic phototroph, heliobacillus mobilis

  • Lee, Woo-Yiel;Bla;Kim, Seung-Ho
    • Journal of Microbiology
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    • 제35권3호
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    • pp.206-212
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    • 1997
  • Heliobacillus mobilis is a strictly anaerobic Gram-positive bacterium which contains a primitive Photosystem I-type reaction center. The membrane-bound cytochrome $C_{553}$ from the heliobacterium suggested to be the immediate electron donor to the photooxidized pigment (P798+) has been isolated and characterized. The heme protein was visualized as a major component with an apparent molecular size of 17kDa in TMBZ-staining analysis of the membrane preparation and showed characteristic $\alpha$ (552.5 nm), $\beta$ (522nm), and Soret absorption (416 nm) peaks of a typical reduced c-type cytochrome in the partially purified sample. The internal 43 amino acid sequence of the electron donor was obtained by chemical agent and protease treatments followed by N-terminal sequencing of the resulting fragments. The internal sequence carries lots of lysine residues and a Cys-X-X-Cys-His sequence motif which are the characteristics of typical c-type cytochromes. The analysis of the sequence by FAST or FASTA program, however, did not show any significant similarity to other known heme proteins.

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