Characterization of Ephrin-A1 and Ephrin-A4 as Ligands for the EphA8 Receptor Protein Tyrosine kinase

Choi, Sunga,Jeong, Jaemin,Kim, Taewoong,Park, Soochul Korean Society of Molecular Biology 1999 Molecules and cells Vol.9 No.4

Phosphorylation at Tyr-838 in the kinase domain of EphA8 modulates Fyn binding to the Tyr-615 site by enhancing tyrosine kinase activity

Choi, Sunga,Park, Soochul 한림대학교 부설 환경ㆍ생명과학연구소 1999 일송 의학ㆍ생명과학 심포지엄 Vol.- No.1

Eph-related receptors and their ephrin lignds are highly conserved protein families which play important roles in targeting axons and migrating cells. In this study we have examined the functional roles of two major autophosphorylation sites, Tyr-615 and Tyr-838, in the EphA8 receptor. Two-dimensional phosphopeptide mapping analysis demonstrated that Tyr-615 and Tyr 838 constitute major autophosphorylation sites in EphA8. Tyr-615 was phosphorylated to the highest stoichiometry, suggesting that phosphorylation at this site may have a physiologically important role. Upon conservative mutation of Tyr 838 located int he tyrosine kinase domain, the catalytic activity of EphA8 was strikingly reduced both in vitro and in vivo, whereas a mutation at Tyr-615 in the juxtamembrane domain did not impair the tyrosine kinase activity. In vitro binding experiments revealed that phosphorylation at Tyr-615 in EphA8 emdiates the preferential binding to Fyn-SH2 domain rather than Sre and Ras GTPase-activating protein (Ras GAP-SH2 domains. Addtionally, a high level of EphA8 was detected in Fyn immunoprecipitates in intact cells, indicating that EphA8 and Fyn can physically, associate in vivo. In contrast, the association of full-length Fyn to EphA8 containing mutation at either Tyr-615 or Tyr 838 was greatly reduced. These data indicate that phosphorylation of Tyr-615 is critical for determining the association with Fyn whereas the integrity of Tyr-838 phosphorylation is required for efficient phosphorylation at Tyr-615 as well aw other major sites. Finally, it was observed that cell attachment responses are attenuated by overexpression of wild type EphA8 receptor but to much less extent by EphA8 mutants lacking phosphorylation at ixtent by EphA8 mutants lacking phosphorylation at either Tyr-615 or Tyr 838. furthermore, transient expression of kinase-inactive Fyn in EphA8-overexpressing cells blocked cell attachment responses attenuated by the EphA8 signaling. We therefore propose that Fyn kinase is one of the major downstream targets for the EphA8 signaling pathway leading to a modification of cell adhesion, and that autophosphorylation at Tyr-838 is critical for positively regulating the EphA8 signaling event.

Dynamic Regulation of APE1/Ref-1 as a Therapeutic Target Protein

Choi, Sunga,Joo, Hee Kyoung,Jeon, Byeong Hwa Chonnam National University Medical School 2016 CMJ Vol.52 No.2

<P>Apurinic/apyrimidinic endonuclease 1/redox factor-1 (APE1/Ref-1) is a multifunctional protein that plays a central role in the cellular response to DNA damage and redox regulation against oxidative stress. APE1/Ref-1 functions in the DNA base excision repair pathway, the redox regulation of several transcription factors, and the control of intracellular redox status through the inhibition of reactive oxygen species (ROS) production. APE1/Ref-1 is predominantly localized in the nucleus; however, its subcellular localization is dynamically regulated and it may be found in the mitochondria or elsewhere in the cytoplasm. Studies have identified a nuclear localization signal and a mitochondrial target sequence in APE1/Ref-1, as well as the involvement of the nuclear export system, as determinants of APE1/Ref-1 subcellular distribution. Recently, it was shown that APE1/Ref-1 is secreted in response to hyperacetylation at specific lysine residues. Additionally, post-translational modifications such as phosphorylation, S-nitrosation, and ubiquitination appear to play a role in fine-tuning the activities and subcellular localization of APE1/Ref-1. In this review, we will introduce the multifunctional role of APE1/Ref-1 and its potential usefulness as a therapeutic target in cancer and cardiovascular disease.</P>

Urinary APE1/Ref-1: A Potential Bladder Cancer Biomarker

Choi, Sunga,Shin, Ju Hyun,Lee, Yu Ran,Joo, Hee Kyoung,Song, Ki Hak,Na, Yong Gil,Chang, Seok Jong,Lim, Jae Sung,Jeon, Byeong Hwa IOS PRESS 2016 Disease markers Vol.2016 No.1

단일클론항체를 이용한 면역학적 Aspartate Aminotransferase 함량 측정법의 개발

최성아,김동준,최의열 대한간학회 2003 Clinical and Molecular Hepatology(대한간학회지) Vol.9 No.2

목적: 간질환 진단을 위한 많은 종류의 혈액 내표지자들 중 아미노전이효소(aspartate/alanine aminotransferase, AST/ALT)가 간세포 손상의 민감한 표지자로서 현재 임상검사에 널리 사용되고 있다. 그러나 현재 AST/ALT 검사법은 효소의 활성도를 측정하는 것으로서 효소가 그 활성을 잃어 버린다거나 효소 활성도에 영향을 미치는 여러 인자 등에 의해 효소 활성도 측정이 영향을 받게 된다. 이러한 문제점들을 극복하기 위해서 효소 활성도를 측정하는 기존의 측정법을 보완 또는 대체하여 호소의 농도를 정량할 수 있는 면역학적 진단법의 필요성이 제기되어 왔다. 대상과 방법: AST 효소 활성 대신 혈액 내에서의 효소 농도를 측정할 수 있는 새로운 분석법을 개발하기 위하여 형광으로 표지된 인간 AST 특이 단일클론항체를 이용하여 면역 크로마토그래피 방법을 적용하였다. 면역 진단 카트리지는 형광 검출 용액, 일회용 카트리지 안의 AST 검사 스트립, 그리고 형광 판독기로 구성하였고, 면역 진단 카트리지의 측정은 형광분석기를 제작하여 사용하였다. 전혈 시료 20 μL를 검사용액과 섞어서 검사 카트리지에 적하하고 12분 경과 후 형광분석기를 사용하여 측정하였다. 농도계산을 위하여 내부 계산 프로그램을 설계하엮고 시료 내 AST 농도를 제시하도록 고안하여 경도곡선의 직선성과 검출한계 그리고 검사내 정밀도 등을 계산하였다. 결과: 정상인 243명과 43명의 간질환에서 혈액을 채취하고 형광 면역 크로마토그래피법으로 시료 내의 AST를 검출하고 그 농도를 정량 하였다. 시료 내의 AST는 0-1 mg/L 범위에서 농도 의존적으로 형광세기 비율(A_T/A_c)이 비례하여 증가함을 알 수 있었고(R=0.995), AST의 최소 검출한계는 12 μg/L이며 측정가능 범위에서의 평균 회복률은 102.4%이었다. 검사 내 정밀도는 intra-, inter-assay로 50-800 μg/L 농도에서 검사되었는데 그 결과 변이계수가 각각 CV_s<7%, CV_s<6%로 신뢰할 만한 측정결과를 산출하였다. 정상군에서 평균 AST농도는 35.5 μg/L이고 간질 환자들에서는 평균 266.5 μg/L이었다. 또한 형광 면역 크로마트그래피 측정법은 그 결과가 ELISA나 생화학적인 측정결과와도 잘 일치하였다. (각각 R=0.92, 0.88; N=43). 결론: 본 연구에서는 인간 AST 특히 항체와 면역학적인 방법을 응용하여 혈액 내에서 AST 농도를 측정할 수 있는 형광면역 크로마트그래피 측정법을 개발하였다. 이 AST 농도 측정법은 소량의 전혈을 이용하여 높은 재현성을 보여 주어 AST 효소 활성도를 측정하는 현재의 일반적인 검사방법을 보완 또는 대체할 수 있는 간편하고 빠른 현장검사법으로 판단되며 다른 혈액화학검사 항목에 대해서도 새로운 접근법으로 활용될 수 있을 것으로 기대된다. Background/Aims: For laboratory diagnostics in liver diseases, many enzymes have been used for the assessment of hepatocellular function. Among them, two transaminases, alanine and aspartate aminotransferase, have been regarded as the most sensitive indicators of hepatocellular damage. However, the enhanced enzyme activites of the enzymes do not exactly indicate or represent the cause and progression of diseases in the patients with liver disease. To overcome such limitations, immunological methods have been suggested as one of the alternatives for the replacement or supplement of the conventional enzymatic analysis. Methods: In the hope of developing a new assay system for measuring the AST concentration rather than its activity, we have developed a new assay using fluorescence labeled anti-AST monoclonal antibodies. Blood was obtained from a normal population of 234 patients and 43 liver disease patients. The linearity, limit of detection, and performance of the new assay system were tested and evaluated. The comparability of assay was examined with an ELISA and biochemical assays. Results: The linearity fell in the range of 0-1 mg/L of AST (R=0.995), and the analytical detection limit was 12 μg/L of AST. The mean recovery of the control was 102.4% in a working range. The precision of the intra- and inter-assay in a range of 50-800 μg/L was CVs<7% and CVs<6%, respectively. In the normal population, the mean AST concentration was 35.5 μg/L. The mean AST concentration in patients with liver disease was 266.5 μg/L. The new assay system correlated well with an ELISA and biochemical assay for quantification of AST concentration (R=0.92 and 0.88, respectively; N=43). Conclusions: We have developed a new immunological assay using generated monoclonal antibodies to human cytosolic AST and used them for the development of a fluorescent assay measuring the enzyme mass. Cytosolic AST mass in sera could be measured reproducibly by the immunological method. In conclusion, this study has provided us with a new type of tool for an accurate measurement of the enzyme amount in circulation.

어머니의 양육신념과 양육행동이 유아의 자기조절력과 사회적 리더십에 미치는 영향과 양육행동 매개효과

배성아(SungA Bae),최혜정(HyeJeong Choi) 학습자중심교과교육학회 2021 학습자중심교과교육연구 Vol.21 No.12

목적 본 연구는 어머니의 양육신념과 양육행동이 유아의 자기조절력과 유아 리더십에 영향요인인가를 파악하고 어머니 양육행동의 매개효과를 검정하여 그 중요성과 시사점을 제시하기 위한 것이다. 방법 이를 위해서 4곳의 유아기관으로부터 어머니와 유아를 통하여 2016년 5월 23일부터 6월 10일까지 516부의 자료 연구를 표집하였으며, 회귀분석 및 상관분석과 중다회귀분석을 실시하였다. 결과 이에 대한 결과는 다음과 같다. 첫째, 어머니 양육신념이 유아의 자기조절력에 미치는 영향에서 인성강조는 정서조절에, 지적성취는 행동조절에 유의한 것으로 예측되었다. 또한 환경주의는 행동조절 및 정서조절에 모두 유의미하였다. 둘째, 어머니 양육신념이 유아의 사회적 리더십에 미치는 영향에서는 인성강조는 공동체배려에, 지적성취는 타인존중, 환경주의는 타인존중과 공동체 배려 모두에 유의미한 영향을 미쳤다. 셋째, 어머니 양육행동이 유아 자기조절력에 미치는 영향에서 온정⋅격려는 행동조절에 유의하였다. 과보호⋅허용은 정서조절에, 거부⋅방임은 행동조절, 정서조절에 유의한 것으로 예측되었다. 넷째, 어머니 양육행동이 유아 사회적 리더십에 미치는 영향에서 온정⋅격려는 타인존중에 유의하였다. 과보호⋅허용은 공동체 배려에, 거부⋅방임은 타인존중, 공동체 배려에 유의한 것으로 예측되었다. 다섯째, 어머니 양육신념과 유아 자기조절력 및 사회적 리더십 관계에서 어머니 양육행동의 매개효과 검정결과는 1단계, 2단계, 3단계 모두 통계적으로 유의하였고, 부분 매개효과를 보였다. 결론 결론적으로 어머니 양육신념은 유아발달에 영향요인이며, 양육행동은 부분 매개역할 요인으로 분석되었다. 유아 자기조절력이나 사회적 리더십은 유아의 성장과정 뿐만 아니라 성장 후 사회적응 등 삶의 전반에 영향을 미치게 된다. 다양한 모습의 현대사회가 도래하면서 유아교육은 전통적으로 어머니에게만 의존하기보다는 가정의 부모와 유아교육기관의 교사들과의 적극적인 소통 자세가 필요하며, 이는 유아들을 위한 바람직한 교육환경 조성에 도움이 될 것이다. Objectives The purpose of this study is to provide whether mothers parenting beliefs and parenting behaviors are factors that influence infants self-regulation and leadership. Methods Through mothers and early childhood teachers from 4 early childhood institutions, 516 data were sampled from May 23 to June 10, 2016. Results First, it was predicted that both personality emphasis, and intellectual achievement and maturityism/environmentalism were significant in behavioral regulation and emotional regulation. Second, in the influence of mother-rearing beliefs on the social leadership of young children, it was predicted that personality emphasis/intellectual achievement was significant for respecting others and community consideration, and maturity/environmentalism was significant for respecting others and community consideration. Third, in the influence of mother-rearing behavior on infant self-regulation, warmth, encouragement, and emotional regulation were significant. It was predicted that overprotection and tolerance were significant in emotional regulation, and rejection and neglect were predicted to be significant in behavioral regulation and emotional regulation. Fifth, as a result of testing the mediating effect of mother-rearing behavior in the relationship between mother-rearing beliefs and infant self-regulation, the first, second, and third steps were statistically significant and showed partial mediating effects. Conclusions In conclusion, the improvement of infant self-regulation or social leadership affects not only the infant s growth process, but also the overall life, such as social adaptation after growth. With the advent of various forms of modern society, early childhood education should not traditionally depend only on mothers, but rather, parents of families and teachers of early childhood education institutions should communicate with each other for children.

Mornitoring of Pesticide Residues in Agricultural Products Marketed from the Northern Area of Seoul(2015-16)

Chaeman Choi,Kyungai Park,Soyoung Jung,Sungae Jo,Kyeongah Lee,Yunhee Kim,Haewon Lee,Sangmi Lee,Insil Yu,Kweon Jung 한국농약과학회 2017 한국농약과학회 학술발표대회 논문집 Vol.2017 No.4

허용적 러프집합에 의한 소프트웨어 분류

김성애(SungAe-Kim),최완규(WanKyoo-Choi),이성주(SungJoo-Lee) 한국지능시스템학회 2001 한국지능시스템학회논문지 Vol.11 No.2

소프트웨어의 측정값에 근거하여 소프트웨어 품질에 관한 의사결정을 할 때, 동치관계의 요구조건인 추이적(transitive) 특성이 항상 만족되는 것은 아니다. 순환수(cyclomatic number)가 거의 비슷한 프로그램에서, 하나는 ‘구조적인’ 프로그램 범주에 속하고 또 다른 하나는 ‘비구조적인’ 프로그램 범주에 속한다고 명확히 분류할 수 있는가하는 점이다. 따라서, 본 연구에서는 동치관계보다는 허용적 관계를 만족하는 허용적 러프집합에 근거한 소프트웨어 분류기준을 제시하고자 한다. 분류기준을 생성하기 위한 실험 데이터 집합을 수집하고, 집합 내의 각 원소에 관한 허용적 클래스들을 생성한 후, 각 허용적 클래스들의 중심값을 클러스터링하여 분류기준을 생성한다. 생성된 분류기준을 또 다른 실험 집합에 적용하여 비교 분석한 결과 생성된 분류기준이 타당함을 보여준다. When we decide the software quality based on the software measurement, the transitive property which is a requirement for the equivalence relations is not always satisfied. Given two programs whose cyclomatic numbers are about the same, it is difficult for us to decide clearly that one is ‘structural' and the other is ‘non-structural’. Therefore, we propose a rough set based method for software classification that employs a tolerance relation instead of an equivalence relation. We collect the experiment data and generate the tolerance classes for elements in the experiment data, and generate the classification ranges for the decision of the software quality by clustering the means of the tolerance classes. We also apply the generated classification ranges to another experiment data and show their validity by comparing and analyzing them.

γ-spectrometer를 이용한 토양시료의 라돈농도 측정법에 관한 연구

강성아(Sunga Kang),이상수(Sangsoo Lee),최규락(Guirack Choi),이준행(Junhaeng Lee) 한국방사선학회 2013 한국방사선학회 논문지 Vol.7 No.1

우라늄(²³⁸U)의 붕괴과정에서 생성되는 방사성기체인 라돈(²²²Rn)은 발생원 중 토양에서 85 % 이상으로 토양의 공극률이 클수록 토양 밖으로 방출할 수 있는 가능성이 많은 동위원소이다. 라돈으로부터 인체를 보호하기 위해서 적절한 대책을 세우는데 무엇보다도 정확한 측정기술의 개발이 선행되어야 한다. 이에 본 연구는 고순도게르마늄(HPGe) 검출기를 이용한 감마선 분광분석법으로 라돈을 측정할 경우에는 불안정한 자연방사능의 백그라운드 문제를 줄일 수 있고, 라듐과 라돈의 딸 핵종들을 방사평형에 이르게 한 후 라돈 농도를 측정하였으며, 토양시료에서의 감마선 방출핵종 및 에너지 스펙트럼을 분석하였다. The radioactive gas radon (²²²Rn), which is generated from the decay process of uranium (²³⁸U) originating from the soil of more than 85 percent higher the porosity of the soil, the soil can radiate out the possibility that many isotopes. In order to protect the human body from radon, above all, the development of accurate measurement techniques to formulate appropriate measures should be followed. This study Gamma-ray spectrometry using a high purity germanium (HPGe) detector, if you want to measure radon unstable the nature radiation of the background problems can be reduced, radium and radon daughter nuclides after radioactive equilibrium leads to Radon concentration was measured, the soil samples from the Gamma-ray emitting nuclides, and the energy spectrum is analyzed.

Anthocyanin-Rich Extract from Red Chinese Cabbage Alleviates Vascular Inflammation in Endothelial Cells and Apo E ^−/− Mice

Joo, Hee Kyoung,Choi, Sunga,Lee, Yu Ran,Lee, Eun Ok,Park, Myoung Soo,Park, Kyu Been,Kim, Cuk-Seong,Lim, Yong Pyo,Park, Jong-Tae,Jeon, Byeong Hwa MDPI 2018 INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES Vol.19 No.3

<P>Anthocyanins, the most prevalent flavonoids in red/purple fruits and vegetables, are known to improve immune responses and reduce chronic disease risks. In this study, the anti-inflammatory activities of an anthocyanin-rich extract from red Chinese cabbage (ArCC) were shown based on its inhibitory effects in cultured endothelial cells and hyperlipidemic apolipoprotein <I>E</I>-deficient mice. ArCC treatment suppressed monocyte adhesion to tumor necrosis factor-α-stimulated endothelial cells. This was validated by ArCC’s ability to downregulate the expression and transcription of endothelial adhesion molecules, determined by immunoblot and luciferase promoter assays, respectively. The regulation of adhesion molecules was accompanied by transcriptional inhibition of nuclear factor-κB, which restricted cytoplasmic localization as shown by immunocytochemistry. Administration of ArCC (150 or 300 mg/kg/day) inhibited aortic inflammation in hyperlipidemic apolipoprotein E-deficient mice, as shown by in vivo imaging. Immunohistochemistry and plasma analysis showed that the aortas from these mice exhibited markedly lower leukocyte infiltration, reduced plaque formation, and lower concentrations of blood inflammatory cytokines than those observed in the control mice. The results suggest that the consumption of anthocyanin-rich red Chinese cabbage is closely correlated with lowering the risk of vascular inflammatory diseases.</P>