• 미생물학회지
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• 제32권1호
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• pp.47-52
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• 1994

Campylobacter jejuni에 48${\circ}C$의 열충격을 30분간 주었을 때, HSP90, HSP66, HSP60의 열충격 단백질들이 합성되었고, 이 단백질들은 각각 E. coli의 hsp87, HSP66 (DnaK), HSP58(GroEL)에 상응하는 단백질들이었다. 여러가지의 제한효소로 처리한 C. jejuni의 chromosomal DNA에 E. coli의 groEL(4.0kb)을 probe로 사용하여 Southern hybridization한 결과, 이들과 상동성을 가지는 유전자들이 있음을 확인하였다. C. jejuni의 groEL 유전자를 pWE15 cosmid를 이용하여 recombinant plasmid pLC1을 만들고, 이를 E. coli B178 groEL44 ts mutant에 형질전환시켜 E. coli LC1을 얻었다. 이 pLC1에는 groEL 유전자가 존재하는 5.7kb인 insert DNA가 포함되어 있었고, 그로부터 subcloning한 pLC101에는 groEL을 포함하는 4.0kb의 DNA가 삽입되어 있었다. 이 recombinant plasmid들이 형질전환된 E. coli LC1과 LC101 균주에서는 C. jejuni의 GroEL 단백질이 과다 생산되었다. C. jejuni의 groEL이 cloning된 E. coli LC1은 42${\circ}C$에서의 생장능력이 회복되었고, ${\lambda}$ vir phage에 대한 감수성도 회복되는 등의 chaperon 효과가 입증되었다.

• 한국콘텐츠학회논문지
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• 제12권7호
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• pp.65-75
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• 2012

농경, 산업, 정보, 지식 사회를 거치면서 무의식의 유산으로 아버지(혹은 남성)는 법, 질서, 규제, 보호자, 훈육자 등등의 표상으로 고정화되었다. 본 연구는 전래동화 "빨간모자"를 통해 어린 독자가 사회의 기초적 단위, 즉 '나'를 중심으로 한 가족의 개념을 익히고 동시에 아버지를 제도로서의 단위로 인지하고 있음을 볼 것이다. 영화 <아저씨>의 관객도 전통적 가족의 필요성과 질서의 주체로서의 아버지의 표상을 구하고 있음을 파악하고자 한다. 일반적으로 아버지는 '나'의 강력한 보호자이자 동시에 실체가 없지만 이름만으로도 영향력을 행사하는 형상, 마치 기독교 예배의식에 나타난 하느님 '아버지'처럼 기표만으로도 법, 질서, 금기, 규제 등등을 운용하는 무형적 존재로서도 작동하고 있다. 본고는 "빨간모자"와 <아저씨>의 분석을 통해 아버지의 기표가 어떤 형태로 드러나는지 살펴보고자 한다. 또한 두 장르에서 드러나는 '아버지' 기표의 유사성도 검토하고자 한다. 아버지(남성)는 한편으로 정치적 폭군이거나 범죄자이지만 다른 한편으로 부당한 권력의 대항자로 또는 사회적 약자의 수호자로 나타난다. 이러한 대립적 구도는 우리가 검토한 "빨간모자"와 <아저씨>의 서사적 구조 속에 잘 묻어있다. 동화 속의 아버지는 욕망과 억압의 표상으로 드러나며, 동시에 독자는 아버지의 부재를 통해 가족의 필요성을 깨닫는다. 영화 속의 아버지는 사회적 약자의 수호자로 묘사되며, 전통적 가족의 틀과 질서의 주체로서 그려진다. 이렇게 아버지의 기표는 두 장르에서 사회적 '제도'라는 기의와 조응하면서 인류문화의 기본적인 개념으로 작동되고 있음을 알 수 있다.

• 분석과학
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• 제30권6호
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• pp.348-354
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• 2017

이 연구는 출산 후 1, 3, 6주가 경과한 산모에서 얻은 모유의 단백체 발현 양상과 과 발현 단백질을 검출하는 것을 목적으로 하였다. 샷 건 정량 단백체 분석법을 이용하여 모유 중의 단백질을 동정하였고, 각 수유단계 간에 정량적 비교를 하였다. 각 주의 모유 샘플은 두 명의 산모로부터 얻어진 모유를 혼합하였고, 각 샘플 마다 3회 반복 실험을 하였다. Casein은 모유 내에 가장 많이 존재하는 단백질로서 실험의 정확성을 위하여 제거하였고, 트립신을 이용한 절편 화로 모유 단백질들을 펩타이드로 변환하였다. 처리된 펩타이드들은 역상 C18 미세관 크로마토그래피 및 이온-트랩 질량분석기를 이용하여 분석하였으며, Spectra Counting으로 단백질의 정량적 비교를 하였다. 각 샘플 당, 80-109 개의 단백질을 중복 제거한 후 동정하였다. 당화 단백질, metabolic enzyme, 및 lactoferrin, Carboxylic ester hydrolase, Clusterin을 포함하는 chaperon 효소들이 주로 검출되었다. 각 반복실험에서 재현성 있게 검출되는 63개의 단백질에 대한 정량적 비교분석 결과 25개의 단백질이 통계적으로 유의하게 수유단계에 따라 변화하는 것을 확인할 수 있었고, 특히 Ig lambda-7 chain C region과 Tenascin은 시간에 따라 현저하게 감소하였다. 향후 이와 같은 수유 단계에 따른 모유 내 단백의 변화가 생리적으로 가지는 의미에 관하여 추가적인 연구가 필요하다 생각된다.

• Macromolecular Research
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• 제14권2호
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• pp.166-172
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• 2006

This is a short review article of our recent studies on the ATP-induced, allosteric conformational transition of the chaperonin GroEL complex by solution X-ray scattering. We used synchrotron X-ray scattering with a two-dimensional, charge-coupled, device-based X-ray detector to study (1) the specificity of the chaperonin GroEL for its ligand that induced the allosteric transition, and (2) the identification of the allosteric transition of GroEL in its complicated kinetics induced by ATP. Due to the dramatically increased sensitivity of the X-ray scattering technique based on the use of the two dimensional X-ray detector and synchrotron radiation, different allosteric conformational states of GroEL populated under different conditions were clearly distinguished from each other. It was concluded that solution X-ray scattering is an extremely powerful tool for investigating the equilibrium and kinetics of cooperative conformational transitions of oligomeric protein complex, especially when combined with other spectroscopic techniques such as fluorescence spectroscopy.

• BMB Reports
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• 제56권4호
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• pp.252-257
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• 2023

The hypoxia-inducible factor-1α (HIF-1α) is a key regulator of hypoxic stress under physiological and pathological conditions. HIF-1α protein stability is tightly regulated by the ubiquitin-proteasome system (UPS) and autophagy in normoxia, hypoxia, and the tumor environment to mediate the hypoxic response. However, the mechanisms of how the UPS and autophagy interplay for HIF-1α proteostasis remain unclear. Here, we found a HIF-1α species propionylated at lysine (K) 709 by p300/CREB binding protein (CBP). HIF-1α stability and the choice of degradation pathway were affected by HIF-1α propionylation. K709-propionylation prevented HIF-1α from degradation through the UPS, while activated chaperon-mediated autophagy (CMA) induced the degradation of propionylated and nonpropionylated HIF-1α. CMA contributed to HIF-1α degradation in both normoxia and hypoxia. Furthermore, the pan-cancer analysis showed that CMA had a significant positive correlation with the hypoxic signatures, whereas SIRT1, responsible for K709-depropionylation correlated negatively with them. Altogether, our results revealed a novel mechanism of HIF-1α distribution into two different degradation pathways.

• Asian-Australasian Journal of Animal Sciences
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• 제25권6호
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• pp.818-823
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• 2012

Tall fescue (Festuca arundinacea Schreb.) is an important cool season forage plant that is not well suited to extreme heat, salts, or heavy metals. To develop transgenic tall fescue plants with enhanced tolerance to abiotic stress, we introduced an alfalfa Hsp23 gene expression vector construct through Agrobacterium-mediated transformation. Integration and expression of the transgene were confirmed by polymerase chain reaction, northern blot, and western blot analyses. Under normal growth conditions, there was no significant difference in the growth of the transgenic plants and the non-transgenic controls. However, when exposed to various stresses such as salt or arsenic, transgenic plants showed a significantly lower accumulation of hydrogen peroxide and thiobarbituric acid reactive substances than control plants. The reduced accumulation of thiobarbituric acid reactive substances indicates that the transgenic plants possessed a more efficient reactive oxygen species-scavenging system. We speculate that the high levels of MsHsp23 proteins in the transgenic plants protect leaves from oxidative damage through chaperon and antioxidant activities. These results suggest that MsHsp23 confers abiotic stress tolerance in transgenic tall fescue and may be useful in developing stress tolerance in other crops.

• 한국자기공명학회논문지
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• 제19권3호
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• pp.99-105
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• 2015

Hsp33 is a prokaryotic molecular chaperon that exerts a holdase activity upon response to an oxidative stress at raised temperature. In particular, intramolecular disulfide bond formation between the four conserved cysteines that bind a zinc ion in reduced state is known to be critically associated with the redox sensing. Here we report the backbone NMR assignment results of the half-oxidized Hsp33, where only two of the four cysteines form an intramolecular disulfide bond. Almost all of the resolved peaks could be unambiguously assigned, although the total assignments extent reached just about 50%. Majority of the missing assignments could be attributed to a significant spectral collapse, largely due to the oxidation-induced unfolding of the C-terminal redox-switch domain. These results support two previous suggestions: conformational change in the first oxidation step is localized mainly in the C-terminal zinc-binding domain, and the half-oxidized form would be still inactive. However, some additional regions appeared to be potentially changed from the reduced state, which suggest that the half-oxidized conformation would be an intermediate state that is more labile to heat and/or further oxidation.

• Archives of Pharmacal Research
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• 제26권12호
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• pp.1047-1054
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• 2003

Molecular chaperones have a crucial role in the folding of nascent polypeptides in endoplasmic reticulum. Some of them are known to be sensitive to the modification by electrophilic metabolites of organic pro-toxicants. In order to identify chaperone proteins sensitive to alkyators, ER extract was subjected to alkylation by 4-acetamido-4 -maleimidyl-stilbene-2,2 -disulfonate (AMS), and subsequent SDS-PAGE analyses. Protein spots, with molecular mass of 160, 100, 57 and 36 kDa, were found to be sensitive to AMS alkylation, and one abundant chaperon protein was identified to be protein disulfide isomerase (PDI) in comparison with the purified PDI. To see the reactivity of PDI with cysteine alkylators, the reduced form ($PDI_{red}$) of PDI was incubated with various alkylators containing Michael acceptor structure for 30 min at $38^{\circ}C$ at pH 6.3, and the remaining activity was determined by the insulin reduction assay. Iodoacetamide or N-ethylmaleimide at 0.1 mM remarkably inactivated $PDI_{red}$ with N-ethylmaleimide being more potent than iodoacetamide. A partial inactivation of $PDI_{oxid}$ was expressed by iodoacetamide, but not N-ethylmaleimide (NEM) at pH 6.3. Of Michael acceptor compounds tested, 1,4-benzoquinone ($IC_{50}, 15 \mu$ M) was the most potent, followed by 4-hydroxy-2-nonenal and 1,4-naphthoquinone. In contrast, 1,2-naphthoquinone, devoid of a remarkable inactivation action, was effective to cause the oxidative conversion of $PDI_{red}$ to $PDI_{oxid}$. Thus, the action of Michael acceptor compounds differed greatly depending on their structure. Based on these, it is proposed that POI, one of chaperone proteins in ER, could be susceptible to endogenous or xenobiotic Michael acceptor compounds in vivo system.

• International Journal of Oral Biology
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• 제45권4호
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• pp.190-196
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• 2020

Several factors, including genetic and environmental insults, impede protein folding and secretion in the endoplasmic reticulum (ER). Accumulation of unfolded or mis-folded protein in the ER manifests as ER stress. To cope with this morbid condition of the ER, recent data has suggested that the intracellular event of an unfolded protein response plays a critical role in managing the secretory load and maintaining proteostasis in the ER. Tauroursodeoxycholic acid (TUDCA) is a chemical chaperone and hydrophilic bile acid that is known to inhibit apoptosis by attenuating ER stress. Numerous studies have revealed that TUDCA affects hepatic diseases, obesity, and inflammatory illnesses. Recently, molecular regulation of ER stress in tooth development, especially during the secretory stage, has been studied. Therefore, in this study, we examined the developmental role of ER stress regulation in tooth morphogenesis using in vitro organ cultivation methods with a chemical chaperone treatment, TUDCA. Altered cellular events including proliferation, apoptosis, and dentinogenesis were examined using immunostaining and terminal deoxynucleotidyl transferase dUTP nick end labeling assay. In addition, altered localization patterns of the formation of hard tissue matrices related to molecules, including amelogenin and nestin, were examined to assess their morphological changes. Based on our findings, modulating the role of the chemical chaperone TUDCA in tooth morphogenesis, especially through the modulation of cellular proliferation and apoptosis, could be applied as a supporting data for tooth regeneration for future studies.

• Reproductive and Developmental Biology
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• 제35권3호
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• pp.307-311
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• 2011

Heat shock protein 90 (Hsp90) is ATPase-directed molecular chaperon and affects survival of several cells. In our previous study, inhibitory effect of Hsp90 by inducing cell cycle arrest and apoptosis in the pig embryonic and primary cells was reported. However, its role during early bovine embryonic development is not sufficient. In this study, we traced the effects of Hsp90 inhibitor, 17-allylamino-17-demethoxygeldanamycin (17-AAG), on early bovine embryonic development. We also investigated several indicators of developmental potential, including structural integrity, gene expression (apoptosis-related genes), and apoptosis, which are affected by 17-AAG. Bovine embryos were cultured in the CR1-aa medium with or without 17-AAG for 7 days. In result, significant differences in developmental potential were detected between the embryos that were cultured with or without 17-AAG ($33.1{\pm}9.6$ vs $21.7{\pm}8.3%$). The structural integrity of the blastocysts was examined by differential staining. Blastocysts from the dbcAMP-treated group had higher numbers of ICM, TE, and total cells than those from the untreated group. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) showed that the number of containing fragmented DNA at the blastocyst stage increased in the 17-AAG treated group compared with control (11.2 vs 3.9, respectively). Blastocysts that developed in the 17-AAG treated group had low structural integrity and high apoptotic nuclei than those of the untreated control, resulting in decrease the embryonic qualities of preimplantation bovine blastocysts. The mRNA expression of the pro-apoptotic gene (Bax) increased in 17-AAG treated group, whereas expression of the antiapoptotic gene (Bcl-XL) decreased. In conclusion, Hsp90 also appears to play a direct role in bovine early embryo developmental competence including structural integrity of blastocysts. Also, these results indicate that Hsp90 is closely associated with apoptosis-related genes expression in developing bovine embryos.