• BMB Reports
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• 제40권1호
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• pp.72-81
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• 2007

In order to screen the aging related proteins in human normal colon epithelia, the comparative proteomics analysis was applied to get the two-dimensional electrophoresis (2-DE) profiles with high resolution and reproducibility from normal colon epithelial tissues of young and aged people. Differential proteins between the colon epithelia of two age groups were found with PDQuest software. The thirty five differential protein-spots were identified by peptide mass fingerprint (PMF) based on matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) and database searching. Among them there are sixteen proteins which are significantly up-regulated in the colonic mucosal epithelia of young people group, which include ATP synthase beta chain, electron transfer flavoprotein alpha-subunit, catalase, glutathione peroxidase 1, annexin A2 and heat shock cognate 71 kDa protein, etc.; There are nineteen proteins which are significantly up-regulated in the colonic mucosal epithelia of aged people group, which include far upstream element-binding protein 1, nucleoside diphosphate kinase B, protein disulfide-isomerase precursor and VDAC-2, etc.. The identified differential proteins appear to be involved in metabolism, energy generation, chaperone, antioxidation, signal transduction, protein folding and apoptosis. The data will help to understand the molecular mechanisms of human colon epithelial aging.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2004년도 제22회 춘계학술대회논문집
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• pp.165-172
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• 2004

LE-7A is the main engine of the H-IIA launch vehicle. Under its development, the nozzle suffered from two troubles during startup and shutdown transients of the engine. One is a large side load, which damages the actuator of the nozzle, and the other is damage on regenerative cooling tubes due to high heat load. It has been considered that these problems are caused by a peculiar separation pattern called Restricted Shock Separation (RSS). RSS is observed in several rocket nozzles, for example, LE-7A nozzle, Vulcain nozzle and so on. Their contours are not conventional truncated perfect (TP) nozzle - LE-7A nozzle is a compressed truncated perfect (CTP) nozzle and Vulcain nozzle is a thrust optimized (TO) nozzle. Although it is believed that the occurrence of RSS is affected by the nozzle contour, the mechanisms are not clarified sufficiently yet. In the present paper, a parametric numerical study is carried out to investigate the mechanisms of the occurrence of RSS in CTP nozzles during startup transient. The results show that RSS is caused by the adverse pressure gradient downstream of the Mach disk. The adverse pressure gradient is caused by the interaction of the pressure wave and Mach disk. The method to avoid the occurrence of RSS is also examined. A small step inside the nozzle affects the position of the separation point and prevents RSS. The result shows that the possibility that RSS can be suppressed by controlling the position of the separation point.

• Journal of Ginseng Research
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• 제41권3호
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• pp.403-410
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• 2017

Background: Prenyltransferases catalyze the sequential addition of isopentenyl diphosphate units to allylic prenyl diphosphate acceptors and are classified as either trans-prenyltransferases (TPTs) or cis-prenyltransferases (CPTs). The functions of CPTs have been well characterized in bacteria, yeast, and mammals compared to plants. The characterization of CPTs also has been less studied than TPTs. In the present study, molecular cloning and functional characterization of a CPT from a medicinal plant, Panax ginseng Mayer were addressed. Methods: Gene expression patterns of PgCPT1 were analyzed by quantitative reverse transcription polymerase chain reaction. In planta transformation was generated by floral dipping using Agrobacterium tumefaciens. Yeast transformation was performed by lithium acetate and heat-shock for $rer2{\Delta}$ complementation and yeast-two-hybrid assay. Results: The ginseng genome contains at least one family of three putative CPT genes. PgCPT1 is expressed in all organs, but more predominantly in the leaves. Overexpression of PgCPT1 did not show any plant growth defect, and its protein can complement yeast mutant $rer2{\Delta}$ via possible protein-protein interaction with PgCPTL2. Conclusion: Partial complementation of the yeast dolichol biosynthesis mutant $rer2{\Delta}$ suggested that PgCPT1 is involved in dolichol biosynthesis. Direct protein interaction between PgCPT1 and a human Nogo-B receptor homolog suggests that PgCPT1 requires an accessory component for proper function.

• 한국동물학회지
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• 제33권2호
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• pp.191-199
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• 1990

토끼의 골격근에서 근소포체를 순수 분리하여 SDS-polyacrylamide gel전기영동법과 125 I-concanavalin A표지법으로 단백질과 당단백질의 조성을 조사하였다. 전기영동사에 나타난 대표적인 단백질은 $Ca^2$+-AThase, 80 Kd protein,calsequestrin,high affinity calcium binding protein, intrinsic glycoprotein이었으며, 160 Kd protein, 94 Kd protein,38 Kd protein, 34 Kd protein,24 Kd proteins도 존재하였다.특히, 막성계에 있는 heak protein으로 알려져 있는 80 Kd protein은 본 연구를 통해 주로 근소포체의 terminal cisternae에 들어 있음이 확인되었다. 한편 125 I-concanavalin A표지에 의해 전기영동성에 나타난 대표적인 당단백질은 160 Kd glycoprotein, 94 Kd glycoprotein, calsequestrin, intrinsic glycoprotein의 4종이었다. 이 가운데 94 Kd glycoprotein은 94 Kd glucose-regulated protein으로 추정되며, 본 연구를 통해 근소포체에서도 특히 T-tubule에 다량으로 존재함이 밝혀졌다.

• 생명과학회지
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• 제24권9호
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• pp.1019-1024
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• 2014

근위축은 근육을 사용하지 않음으로써 발생하는 근육 조직의 손실 또는 근육을 지배하는 신경의 손상으로 정의할 수 있다. 이 상태는 다양한 근육질환에 관여하는 활성산소종이 관여 한다. 우리는 심비디움 뿌리 추출물이 과산화수소에 의해 유도된 C2C12 근육세포 생존율 손실과 세포사를 억제한다는 것을 찾았다. 또한 심비디움 뿌리 추출물이 HSP70 단백질 발현증가와 SOD1 단백질 발현감소를 확인하였다. 이들의 결과는 심비디움 뿌리 추출물이 근위축에서 활성산소종을 환원하는 치료약물로서 작용이 가능할 것으로 사료된다.

• Molecules and Cells
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• 제38권2호
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• pp.187-194
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• 2015

Thioredoxin (TRX) is a disulfide reductase present ubiquitously in all taxa and plays an important role as a regulator of cellular redox state. Recently, a redox-independent, chaperone function has also been reported for some thioredoxins. We previously identified nodulin-35, the subunit of soybean uricase, as an interacting target of a cytosolic soybean thioredoxin, GmTRX. Here we report the further characterization of the interaction, which turns out to be independent of the disulfide reductase function and results in the co-localization of GmTRX and nodulin-35 in peroxisomes, suggesting a possible function of GmTRX in peroxisomes. In addition, the chaperone function of GmTRX was demonstrated in in vitro molecular chaperone activity assays including the thermal denaturation assay and malate dehydrogenase aggregation assay. Our results demonstrate that the target of GmTRX is not only confined to the nodulin-35, but many other peroxisomal proteins, including catalase (AtCAT), transthyretin-like protein 1 (AtTTL1), and acyl-coenzyme A oxidase 4 (AtACX4), also interact with the GmTRX. Together with an increased uricase activity of nodulin-35 and reduced ROS accumulation observed in the presence of GmTRX in our results, especially under heat shock and oxidative stress conditions, it appears that GmTRX represents a novel thioredoxin that is co-localized to the peroxisomes, possibly providing functional integrity to peroxisomal proteins.

• Molecules and Cells
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• 제27권2호
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• pp.149-157
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• 2009

In both gram-positive and several gram-negative bacteria, the transcription of dnaK and groE operons is negatively regulated by HrcA; however, the mechanism modulating HrcA protein activity upon thermal stress remains elusive. Here, we demonstrate that HrcA is modulated via reduction and oligomerization in vitro. Native-PAGE analysis was used to reveal the oligomeric structure of HrcA. The oligomeric HrcA structure became monomeric following treatment with the reducing agent dithothreitol, and this process was reversed by treatment with hydrogen peroxide. Moreover, the mutant HrcA C118S exhibited reduced binding to CIRCE elements and became less oligomerized, suggesting that cysteine residue 118 is important for CIRCE element binding as well as oligomerization. Conversely, HrcA mutant C280S exhibited increased oligomerization. An HrcA double mutant (C118S, C280S) was monomeric and exhibited a level of oligomerization and CIRCE binding similar to wild type HrcA, suggesting that cysteine residues 118 and 280 may function as checks to one another during oligomer formation. Biochemical fractionation of E. coli cells overexpressing HrcA revealed the presence of HrcA in the membrane fraction. Together, these results suggest that the two HrcA cysteine residues at positions 118 and 280 function as reduction sensors in the membrane and mediate oligomerization upon stress.

• Molecules and Cells
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• 제41권6호
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• pp.562-574
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• 2018

The tazarotene-induced gene 1 (TIG1) protein is a retinoidinducible growth regulator and is considered a tumor suppressor. Here, we show that DnaJ heat shock protein family member C8 (DNAJC8) is a TIG1 target that regulates glycolysis. Ectopic DNAJC8 expression induced the translocation of pyruvate kinase M2 (PKM2) into the nucleus, subsequently inducing glucose transporter 1 (GLUT1) expression to promote glucose uptake. Silencing either DNAJC8 or PKM2 alleviated the upregulation of GLUT1 expression and glucose uptake induced by ectopic DNAJC8 expression. TIG1 interacted with DNAJC8 in the cytosol, and this interaction completely blocked DNAJC8-mediated PKM2 translocation and inhibited glucose uptake. Furthermore, increased glycose uptake was observed in cells in which TIG1 was silenced. In conclusion, TIG1 acts as a pivotal repressor of DNAJC8 to enhance glucose uptake by partially regulating PKM2 translocation.

• Genomics & Informatics
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• 제4권2호
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• pp.71-76
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• 2006

We have investigated biological responses to radiofrequency (RF) radiation in in vitro and in vivo models. By measuring the levels of heat shock proteins as well as the activation of mitogen activated protein kinases (MAPKs), we could not detect any differences upon RF exposure. In this study, we used more sensitive method to find the molecular responses to RF radiation. Jurkat, human T-Iymphocyte cells were exposed to 1763 MHz RF radiation at an average specific absorption rate (SAR) of 10 W/kg for one hour and harvested immediately (R0) or after five hours (R5). From the profiles of 30,000 genes, we selected 68 differentially expressed genes among sham (S), R0 and R5 groups using a random-variance F-test. Especially 45 annotated genes were related to metabolism, apoptosis or transcription regulation. Based on support vector machine (SVM) algorithm, we designed prediction model using 68 genes to discriminate three groups. Our prediction model could predict the target class of 19 among 20 examples exactly (95% accuracy). From these data, we could select the 68 biomarkers to predict the RF radiation exposure with high accuracy, which might need to be validated in in vivo models.

• 대한약침학회지
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• 제12권1호
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• pp.5-12
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• 2009

Background : Anticancer effects of herbal medicine have been reported in various types of cancer, but the systematic approaches to explain molecular mechanism(s) are not established yet. Objective : To find the anticancer-effect and mechanism(s) of Water Extract of Coptis japonica (WECJ) colon cancer cell (SNU-81). Methods : We first selected 11 herbals, and anti-cancer effects of water-extracts from those herbals have been tested in human colon cancer cell line, SNU-81. Among the tested herbals, the WECJ significantly reduced proliferation of SNU-81. To establish a basis of understanding for anti-cancer mechanism, whole proteins have been obtained from SNU-81 harvested at 48 and 96 hrs after the treatment of WECJ, protein expression has been profiled by 2DE-based proteomic approach. Results : Various changes of the protein expression have been monitored, and most frequent dysregulation was found in the molecular chaperons including heat shock protein 90-alpha (Hsp90-alpha), 14-3-3 protein epsilon, T-complex protein 1 subunit alpha, protein disulfide-isomerase A3, and calreticulin. Interestingly, proliferation-associated protein 2G4 has been up-regulated, and it suggests the possible effect of Coptis japonica on ErbB3-regulated signal transduction pathway and growth control of human colon cancer cells. Conclusion : Based upon the present findings, the further study will focus on monitoring various cancer survival factors after artificial regulation of the proteins identified, and it would be the basis for the understanding of the Coptis japonica anti-cancer effect(s) at the molecular level.