• Molecules and Cells
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• 제21권3호
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• pp.381-388
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• 2006

Heat shock proteins (Hsp) 70 are a ubiquitous family of molecular chaperones involved in many cellular processes. A yeast strain, ssa1/2, with two functionally redundant cytosolic Hsp70s (SSA1 and SSA2) deleted shows thermotolerance comparable to mildly heatshocked wild type yeast, as well as increased protein synthesis and ubiquitin-proteasome protein degradation. Since mRNA abundance does not always correlate well with protein expression levels it is essential to study proteins directly. We used a gel-based approach to identify stress-responsive proteins in the ssa1/2 mutant and identified 43 differentially expressed spots. These were trypsin-digested and analyzed by nano electrospray ionization liquid chromatography tandem mass spectrometry (nESI-LC-MS/MS). A total of 22 non-redundant proteins were identified, 11 of which were confirmed by N-terminal sequencing. Nine proteins, most of which were up-regulated (2-fold or more) in the ssa1/2 mutant, proved to be stress-inducible proteins such as molecular chaperones and anti-oxidant proteins, or proteins related to carbohydrate metabolism. Interestingly, a translational factor Hyp2p up-regulated in the mutant was also found to be highly phosphorylated. These results indicate that the cytosolic Hsp70s, Ssa1p and Ssa2p, regulate an abundance of proteins mainly involved in stress responses and protein synthesis.

• Molecules and Cells
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• 제37권11호
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• pp.833-840
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• 2014

Cullin4-RING ubiquitin ligase (CRL4) is a family of multi-subunit E3 ligases. To investigate the possible involvement of CRL4 in heat stress response, we screened T-DNA insertion mutants of putative CRL4 substrate receptors that exhibited altered patterns in response to heat stress. One of the mutants exhibited heat stress tolerance and was named heat stress tolerant DWD1 (htd1). Introduction of HTD1 gene into htd1-1 led to recovery of heat sensitivity to the wild type level, confirming that the decrease of HTD1 transcripts resulted in heat tolerance. Therefore, HTD1 plays a negative role in thermotolerance in Arabidopsis. Additionally, HTD1 directly interacted with DDB1a in yeast two-hybrid assays and associated with DDB1b in vivo, supporting that it could be a part of a CRL4 complex. Various heat-inducible genes such as HSP14.7, HSP21, At2g03020 and WRKY28 were hyper-induced in htd1-1, indicating that HTD1 could function as a negative regulator for the expression of such genes and that these genes might contribute to thermotolerance of htd1-1, at least in part. HTD1 was associated with HSP90-1, a crucial regulator of thermotolerance, in vivo, even though the decrease of HTD1 did not affect the accumulation pattern of HSP90-1 in Arabidopsis. These findings indicate that a negative role of HTD1 in thermotolerance might be achieved through its association with HSP90-1, possibly by disturbing the action of HSP90-1, not by the degradation of HSP90-1. This study will serve as an important step toward understanding of the functional connection between CRL4-mediated processes and plant heat stress signaling.

• The Korean Journal of Physiology and Pharmacology
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• 제5권1호
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• pp.47-53
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• 2001

Drinking excessive alcohol has been recognized as a risk factor for hypertension. However, the mechanism by which alcohol intake causes hypertension still remains elusive. We tested the hypothesis that ethanol itself acts as a stress factor on vasculature and indirectly modulates vascular contractility. After end of exposure to 1, 2.5 and 5% ethanol for 45 min, rat aortic strips were subjected to contractile responses, immunoblot for Hsp70 and the measurement of levels of myosin light chain phosphorylation. Exposure to 5% ethanol not only augmented contractions to KCl or phenylephrine, but also increased expression of Hsp70 and the levels of myosin light chain phosphorylation. There were no significant differences in contractions produced by $1\;{\mu}mol/L$ phorbol 12,13-dibutyrate, a protein kinase C activator, whether the tissues were exposed to 5% ethanol or not. This is the first report to show that even short exposure to ethanol has a delayed effect to increase vascular smooth muscle contractility through a modulation of thick filament regulation. It may be a mechanism by which ingestion of alcohol induces hypertension.

• Genomics & Informatics
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• 제11권1호
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• pp.52-54
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• 2013

Proteins in DNAJ/K families are ubiquitous, from prokaryotes to eukaryotes, and function as molecular chaperones. For systematic phylogenomics of the DNAJ/K families, we developed the Eukaryotic DNAJ/K Database (EDD). A total of 12,908 DNAJs and 4,886 DNAKs were identified from 339 eukaryotic genomes in the EDD. Kingdom-wide comparison of DNAJ/K families provides new insights on the evolutionary relationship within these families. Empowered by 'class', 'cluster', and 'taxonomy' browsers and the 'favorite' function, the EDD provides a versatile platform for comparative genomic analyses of DNAJ/K families.

• Childhood Kidney Diseases
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• 제4권2호
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• pp.161-165
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• 2000

저자들은 남매에서 3주 정도의 차이를 둔 비슷한 시기에 피부의 자반성 구진, 관절의 부종 및 관절통을 주소로 내원하여 HS 자반증으로 진단받은 두명의 환아를 경험하였기에 문헌고찰과 함께 보고하는 바이다.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.336.1-336.1
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• 2002

HSP100/Clp family functions as molecular chaperone and ATP dependent protease. The Streptococcus pneumoniae ClpL. a homologue of bacterial ClpB and yeast cytosolic HSP 104. is one of major heat shock proteins but its biochemical properties are unknown. In this study. ClpL in Streptococcus pneumoniaewas characterized using histidine tagged recombinant ClpL. When ATP hydrolysis activity was compared in the presence or absence of a variety of nucleotides or divalent ions. either ATP or Mn$2^＋$ ion was found to increase significantly the rate of ATP hydrolysis. Furthermore. glutaraldehyde cross-linking and subsequent native-PAGE analfysis showed that ClpL forms dimer. but in the presence of 4 mM concentration of $Mn^{2＋}$ion as a cofactor for ATP hydrolysis and oligormerization in vitro.

• The Plant Pathology Journal
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• 제24권2호
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• pp.131-142
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• 2008

Magnaporthe oryzae, the causal agent of the rice blast disease, poses a worldwide threat to stable rice production. The large-scale functional characterization of genes controlling the pathogenicity of M. oryzae is currently under way, but little is known about heat shock protein 40 (Hsp40) function in the rice blast fungus or any other filamentous plant pathogen. We identified 25 genes encoding putative Hsp40s in the genome of M. oryzae using a bioinformatic approach, which we designated M. oryzae heat shock protein forty (MHF 1-25). To elucidate the roles of these genes, we characterized the functions of MHF16 and MHF21, which encode type ill and type n Hsp40 proteins, respectively. MHF16 and MHF21 expression was not significantly induced by heat shock, but it was down-regulated by cold shock. Knockout mutants of these genes $({\Delta}$mhf16 and ${\Delta}$mhf21) were viable, but conidiation was severely reduced. Moreover, sectoring was observed in the ${\Delta}mhf16$ mutant when it was grown on oatmeal agar medium. Conidial germination, appressorium formation, and pathogenicity in rice were not significantly affected in the mutants. The defects in conidiation and colony morphology were fully complemented by reintroduction of wild type MHF16 and MHF21 alleles, respectively. These data indicate that MHF16 and MHF21 play important roles in conidiation in the rice blast fungus.

• 생명과학회지
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• 제11권5호
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• pp.464-469
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• 2001

내염성의 광합성 cyanobateria 인 Aphanothece halophytica로 부터 molecular chaperone으로 가능하는 HSP70 homolog인 dnaK2 유전자를 cloning 하였다. 이 danK2 유전자는 616개의 아미노산으로 구성되었으며 추정되는 분자량 68 kDa 의 단백질을 code하고 있었다. 아미노산 서열로부터 추정되는 DnaK2 단백질의 구조를 분석하여 본 결과, 다른 원핵생물의 DanK2 단백질들이 공통적으로 갖는 특성인 N-terminal ATPase domain과 C-terminal의 peptide-binding domain이 잘 보존되어 있었으며, 다른 HSP70/DanK 단백질들과의 높은은 상동성을 나타내었다. 한편 danK2 유전자는 생장온도인 28$^{\circ}C$에서 낮은 수준으로 구성적으로 발현하였으며 heat stress에 의해 그 발현량이 급격히 증가하였다. 또한 A. halophytica를 고농도의 염 스트레스로 처리한 결과, heat stress가 없음에도 불구하고 그 발현량이 급격히 증가하였다. 이러한 결과들은 DnaK 단백질의 고온 또는 염 스트레스에 따른 세포의 손상을 보호하기 위하여 중요한 기능을 담당하고 있기 때문에 추정된다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제36권5호
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• pp.346-352
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• 2010

Introduction: Heat shock protein70 (HSP70) is a highly conserved family of proteins produced after a variety of stresses. Many studies reported that the overexpression of HSP70 can improve the prognosis of the patients with sepsis through a reduction of the nitric oxide concentration. However, these results only revealed the effect of HSP70 and nitric oxide. No studies have examined the relationship between HSP70 and nitric oxide. The aim of this study was to evaluate the effect of the overexpression of HSP70 on the expression of inducible nitric oxide synthase and the nitric oxide concentration. In addition, the mechanism of the relationship of HSP70 and inducible nitric oxide synthase (iNOS) in sepsis was examined. Materials and Methods: The experiments were performed on male sprague-dawley rats. Sepsis was induced by a cecal ligation and puncture (CLP). Glutamine (GLN) or saline was administered 1 hour after the initiation of sepsis. Serum and lung tissues were acquired from the rats 12 hours or 24 hours after the initiation of sepsis. The nitric oxide concentration, the expression of HSP70 in lung, and the gene expression of iNOS in lung were analyzed. The three groups, sham operation, CLP and CLP+GLN, were compared. Results: Compared to the other groups, in CLP+GLN, GLN administered after the initiation of sepsis enhanced the expression of HSP70 in the lung at 12 hours ($47.19{\pm}10.04$ vs. $33.22{\pm}8.28$, P=0.025) and 24 hours ($47.06{\pm}10.60$ vs. $31.90{\pm}4.83$, P=0.004). In CLP+GLN, GLN attenuated the expression of iNOS messenger RNA (mRNA) in the lung at 12 hours ($5,513.73{\pm}1,051.60$ vs. $4,167.17{\pm}951.59$, P=0.025) and 24 hours ($18,740.27{\pm}8,241.20$ vs. $9,437.65{\pm}2,521.07$, P=0.016), and reduced the concentration of nitric oxide in the serum at 12 hours ($0.86{\pm}0.48$ vs. $3.82{\pm}2.53$, P=0.016) and 24 hours ($0.39{\pm}0.25$ vs. $1.85{\pm}1.70$, P=0.025). Conclusion: The overexpression of HSP70 induced by the administration of GLN in sepsis attenuates the expression of the iNOS gene but reduces the nitric oxide concentration.

• 한국동물학회:학술대회논문집
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• 한국동물학회 2003년도 한국생물과학협회 학술발표대회
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• pp.189.4-189
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• 2003

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