• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 2003년도 정기총회 및 학술발표회
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• pp.66-66
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• 2003

In skeletal muscle cells, depolarization of the transverse tubules (T-tubules) results in Ca$\^$2+/ release from the sarcoplasmic reticulum (SR), leading to elevated cytoplasmic Ca$\^$2+/ and muscle contraction. This process has been known as excitation-contraction coupling (E-C coupling). Several proteins, such as the ryanodine receptor (RyR), triadin, junctin, and calsequestrin (CSQ), have been identified to be involved in the Ca$\^$2＋/ release process. However, the molecular interactions between the SR proteins have not been resolved. In the present study, the mechanisms of interaction between RyRl and triadin have been studied by in vitro protein binding and $\^$45/Ca$\^$2+/ overlay assays. Our data demonstrate that the intraluminal loop II of RyR1 binds to triadin in Ca$\^$2+/-independent manner. Moreover, we could not find any Ca$\^$2+/ binding sites in the loop II region. GST-pull down assay revealed that a KEKE motif of triadin, which was previously identified as a CSQ binding site (Kobayasi et al.,2000 JBC) was also a binding site for RyR1. Our results suggest that the intraluminal loop II of RyR could participate in the RyR-mediated Ca$\^$2+/ release process by offering a direct binding site to luminal triadin.

• Molecules and Cells
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• 제39권2호
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• pp.149-155
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• 2016

In the heart, excitation-contraction (E-C) coupling is mediated by $Ca^{2+}$ release from sarcoplasmic reticulum (SR) through the interactions of proteins forming the $Ca^{2+}$ release unit (CRU). Among them, calsequestrin (CSQ) and histidine-rich $Ca^{2+}$ binding protein (HRC) are known to bind the charged luminal region of triadin (TRN) and thus directly or indirectly regulate ryanodine receptor 2 (RyR2) activity. However, the mechanisms of CSQ and HRC mediated regulation of RyR2 activity through TRN have remained unclear. We first examined the minimal KEKE motif of TRN involved in the interactions with CSQ2, HRC and RyR2 using TRN deletion mutants and in vitro binding assays. The results showed that CSQ2, HRC and RyR2 share the same KEKE motif region on the distal part of TRN (aa 202-231). Second, in vitro binding assays were conducted to examine the $Ca^{2+}$ dependence of protein-protein interactions (PPI). The results showed that TRN-HRC interaction had a bell-shaped $Ca^{2+}$ dependence, which peaked at pCa4, whereas TRN-CSQ2 or TRN-RyR2 interaction did not show such $Ca^{2+}$ dependence pattern. Third, competitive binding was conducted to examine whether CSQ2, HRC, or RyR2 affects the TRN-HRC or TRN-CSQ2 binding at pCa4. Among them, only CSQ2 or RyR2 competitively inhibited TRN-HRC binding, suggesting that HRC can confer functional refractoriness to CRU, which could be beneficial for reloading of $Ca^{2+}$ into SR at intermediate $Ca^{2+}$ concentrations.

• Molecules and Cells
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• 제22권3호
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• pp.328-335
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• 2006

Imperatoxin A ($IpTx_a$), a 3.7 kDa peptide from the African scorpion Pandinus imperator, is an agonist of the skeletal muscle ryanodine receptor (RyR1). In order to study the structure of the toxin and its effect on RyR1, $IpTx_a$ cDNA was PCR-amplified using 3 pairs of primers, and the toxin was expressed in E. coli. The toxin was further purified by chromatography, and various point mutants in which basic amino acids were substituted by alanine were prepared by site-directed mutagenesis. Studies of single channel properties by the planar lipid bilayer method showed that the recombinant $IpTx_a$ was identical to the synthetic $IpTx_a$ with respect to high-performance liquid chromatography mobility, amino acid composition and specific effects on RyR1. Mutations of certain basic amino acids ($Lys^{19}$, $Arg^{23}$, and $Arg^{33}$) dramatically reduced the capacity of the peptide to activate RyRs. A subconductance state predominated when $Lys^8$ was substituted with alanine. These results suggest that some basic amino acid residues in $IpTx_a$ are important for activation of RyR1, and that $Lys^8$ plays an important role in regulating the gating mode of RyR1.

• 대한약리학회지
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• 제32권1호
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• pp.57-66
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• 1996

파충류 골격근의 근소포체에서 칼슘유리 채널의 존재를 밝히고저 뱀 골격근에서 근소포체를 분리하여 SDS-PAGE 전기영동, RyR의 정제, $[^3H]ryanodine$ 결합실험 및 $^{45}Ca$ 유리 실험으로 아래와 같은 결과를 얻었다. 1) 뱀골격근 소포체도 단일 band의 high molecular weight 단백을 가지고 있고, 그 mobility는 포유류 골격근의 것과 유사했다. 2) RyR의 정제과정에서 얻어진 $[^3H]ryanodine$의 peak 결합 분획에서 high molecular weight의 단백분획이 발견되었다. 3) 뱀 골격근 SR vesicles에 대한 $[^3H]ryanodine$의 maximum binding site와 Kd값은 각각 6.36 pmole/mg protein과 17.62nM이었으며, $[^3H]ryanodine$의 특이성 결합은 칼슘과 AMP에 의해 유의성있게 증가되었고 (P<0.005), tetracaine에 의해 억제되지 않았으나 ruthenium red와 $MgCl_2$에 의해 일부만 억제되었다. 4) 근 소포체로부터 $^{45}Ca$ 유리는 낮은 농도의 칼슘 $(1{\sim}10{\mu}M)$과 AMP에 의해 증가되었고 (P<0.05), 고농도의 칼슘 $(300{\mu}M)$, tetracaine, ruthenium red 또는 $MgCl_2$에 의해 억제되었다 (P<0.05). 이상의 실험성적으로 파충류 (뱀)의 골격근에도 칼슘유리 채별이 있어 근 수축시 세포내 칼슘 농도 조절에 관여할 수 있을 것으로 여겨지며, 채널의 기능적 특징 일부가 포유류의 것과 유사한 것으로 사료된다.

• Journal of Ginseng Research
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• 제20권3호
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• pp.274-283
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• 1996

In this study, the effects of red ginseng components [ginsenosides (total saponins and $Rg_1$) on the function of ryanodine receptor (RyR) -$Ca^{2+}$ release channel complex protein (named as RyR or $Ca^{2+}$ channel), a membrane protein in sarcoplasmic reticulum (SR) of rabbit skeletal muscle were examined at the SR vesicle's level and the molecular levels with Chaps-solubilized and purified $Ca^{2+}$ channel protein and with reconstituted proteoliposomes by dialysis. The results were as follows. 1. The binding of ryanodine known as inhibitor of muscle contraction to the RyR was decreased at the whole range of concentration ($10^2$~$10^7$%) by these two ginseng components. In heavy SR vesicles, Chaps-solubilized and purified $Ca^{2+}$ channel protein, and reconstituted vesicles, its maximal inhibition by total saponins was shown at the concentration of $10^3$, $10^3$%, and $10^5$% respectively, and by gin- senoside $Rg_1}$) each was $10^3$%, $10^3$%, and $10^4$%. 2. The release of $Ca^{2+}$ ion through $Ca^{2+}$ channel in heavy SR vesicles and reconstituted proteoliposomes was increased as a whole by these two ginseng components, and particularly maximal release by both of them was shown at the range of $10^4$~$10^6$%. These results were seemed to be caused by conformational change of $Ca^{2+}$ release channel protein (RyR) by red ginseng components [ginsenosides (total saponins and $Rg_1}$).

• 천문학논총
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• 제30권2호
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• pp.229-230
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• 2015

The results of spectral studies of the CTTS type young star RY Tau with spectrograms of the ultraviolet and the visual ranges are presented. We show the first detection of periodic variability of the emission line intensities in UV and visual ranges with a period of 23 days.

• 한국응용곤충학회지
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• 제55권4호
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• pp.413-419
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• 2016

Chlorantraniliprole은 곤충 근육의 $Ca^{2+}$ 농도를 조절하는 Ryanodine 수용기(RyR)에 작용 하는 diamide계통의 작물보호제이다. 최근에 보고된 chlorantraniliprole 저항성 배추좀나방 계통은 RyR에 돌연변이를 가지고 있다. 본 연구에서는 초파리를 모델 곤충으로 저농도와 고농도의 chlorantraniliprole로 도태된 두 종류의 저항성 계통을 확보하였다. 두 종류의 저항성 계통은 접촉독성과 섭식독성 평가법을 활용하여 저항성 지수를 산출하였다. 접촉 독성 평가에서 두 종류의 저항성 계통은 대조군과 비교하여 95% 신뢰구간에서 저항성 발달에 차이가 없었지만, 섭식 독성 평가의 경우에서는 고농도 저항성 계통과 저농도 저항성 계통에서 대조군 대비 각각 2.1배와 8.1배의 통계적으로 유의한 저항성 증가가 나타났다. 작용점 유전자인 RyR 발현량 비교 결과, 두 종류의 저항성 계통에서 RyR의 발현량이 유의하게 감소하였고, 주요 약제 관련 효소인 Acetylcholinesterase와 Glutathione-S-transferase 활성은 조직 특이적으로 증가하는 것을 확인하였다. 이러한 결과들은 초파리에서 chlorantraniliprole에 대한 섭식독성 저항성의 발달에는 주요 해독 관련 효소의 과활성도 관여할 것 임을 보여주고 있다.

• 한국산림과학회지
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• 제109권2호
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• pp.202-210
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• 2020

본 연구는 일본잎갈나무 임분의 안정성을 고려한 임분밀도 관리의 적정 수준을 탐색하기 위해 수행하였다. 분석에 활용된 조사 표본점 259개소의 자료를 통해 임분밀도관리도를 개발하였고, 이를 이용하여 상대수확량지수(Relative yield index: Ry)와 형상비(Height-to-diameter ratio: H/D)간의 관계 구명을 통해 임분밀도 관리의 적정 수준을 찾고자 하였다. 추정된 임분밀도관리도의 설명력(R²)은 0.600으로 나타났다. 상대수확량지수와 세장목의 출현비율의 관계 분석 결과, 일정임분밀도 이상에 도달할 경우 세장목의 비율이 급격히 증가하였고, 해당 곡선에서의 상대수확량지수(Ry)의 임계값은 0.63으로 분석되었다. 본 연구의 결과는 풍해, 설해와 같은 자연적인 피해를 저감 할 수 있는 임분 관리 전략 수립과 경제림의 생산력 향상을 위한 임분 시업체계 개발에 기여할 것으로 사료된다.

• 약학회지
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• 제48권6호
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• pp.352-357
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• 2004

Atrial myocytes have two functionally separate groups of ryanodine receptors (RyRs): those at the periphery colocalized with L-type $Ca^{2+}$channels (DHPRS) and those a t the cell interior not associated with DHPRs. $Ca^{2+}$ current ($I_{ca}$) directly gates peripheral RyRs on action potential and the subsequent peripheral $Ca^{2+}$ release propagates into the center of atrial myocytes. The mechanisms that regulate the $Ca^{2+}$+ propagation wave remain Poorly understood. Using 2-D confocal$Ca^{2+}$ imaging, we examined the role of inositol 1,4,5-trisphosphate receptor (IP $_3R$) and mitochondria on ($I_{ca}$)- gated local $Ca^{2+}$ signaling in rat atrial myocytes. Blockade of IP $_3R$ by xestospongin C (XeC) partially suppressed the magnitudes of I ca-gated central and peripheral $Ca^{2+}$ releases with no effect on $I_{ca}$. Mitochondrial staining revealed that mitochondria were aligned with ${\thickapprox}2-{\mu}m$ separations in the entire cytoplasm of ventricular and atrial myocytes. Membrane depolarization induced rapid mitochondrial $Ca^{2+}$ rise and decay in the cell periphery with slower rise in the center, suggesting that mitochondria may immediately uptake cytosolic $Ca^{2+}$, released from the peripheral SR on depolarization, and re-release the $Ca^{2+}$ into the cytosol to activate neighboring central RyRs. Our data suggest that the activation of IP $_3R$ and mitochondrial $Ca^{2+}$ handing on action potential may serve as a cofactor for the $Ca^{2+}$ propagation from the DHPR-coupled RyRs to the DHPR-uncoupled RyRs with large gaps between them.

• 한국응용곤충학회지
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• 제35권4호
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• pp.297-301
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• 1996

온도가 살충제의 저항성과 감수성계통, 복숭아혹진덧물의 발육에 미치는 영향을 조사하기 위하여 핵형이 정상인 감수성 계통(URY-O)과 저항성 계통(ABURABI : 유일) 및 핵형이상(AI, 3 전좌)으로 저항성인 O-RY 계통을 사용하였다. $25{\circ}C$에서의 약충 기간은 저항성과 감수성 계통 간에 차이가 없었으나, $30{\circ}C$에서는 감수성 인 URY-O 계통은 8.3일간에 성층이 되었었음에 비하여 저항성인 O-RY 계통은 조사기간인 20일까지 약충상태로서 성충으로 발육하지 못하고 사망하였다. 감수성인 URY-O 계통과 저항성인 ABURABI 계통의 산자수는 $28^{\circ}C\;와\;25^{\circ}C$에서 서로 차이가 없었으나, 저항성인 O-RY 계통의 산자 수는 $28^{\circ}C\;에서\;25^{\circ}C$에서보다 1/10밖에 자충을 낳지 못하였다. 또한 충체중은 $28^{\circ}C$에서 URY-O와 유일은 각각 0.22와 0.27 mg/♀이었으나, O-RY는 0.16 mg/♀로서 차이가 컸다. 가수분해활성(n mol/IS min/female)이 19인 O-RY(-)9t 88인 O-RY(+)는 $28^{\circ}C에서\;G_1$, sub-strain의 산자수는 각각 3.4마리와 0.8마리로서 에스테라제 활성이 높은 O-RY(+)계통이 에스테라제 활성이 낮은 O-RY(-)계통보다 새끼수를 적게 낳았다.