• 미생물학회지
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• 제29권1호
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• pp.49-55
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• 1991

The heat shock responses of Campylobacter jejuni were studied by examination of their survival rates and synthesis of heat shocd proteins. When C. jejuni cells were treated at the sublethal temperatures of 48.deg.C for 30 minutes, most of the cells maintained their viabilities and synthesized the heat shock proteins of 90, 73, and 66 kD in molecular weight. By the method of two-dimensional electrophoresis, the heat shock proteins of C. jejuni were identified to be Hsp90, Hsp73, and Hsp66. During the heat shock at 48.deg.C, the heat shock proteins were induced from about 5 minutes after the heat shock treatment. Their synthesis was continued upto 30 minutes, but remarkably retarded after 50 minutes. When C. jejune cells were heat shocked at 51.deg.C for 30 minutes, the survival rates of the cells were decreased by about $10^{3}$ fold and synthesis of heat shock proteins and normal proteins was also generally retarded. The cells exposed to 55.deg.C for 30 minutes died off by more than $10^{5}$ cells and the new protein synthesis was not observed. But when C. jejuni cells were heat-shocked at the sublethal temperature of 48.deg.C for 15 to 20 minutes and then were exposed at the lethal temperature of 55.deg.C for 30 minutes, their viabilities were higher than those exposed at 55.deg.C for 30 minutes without pre-heat shock at 48.deg.C. Therefore, the heat shock proteins synthesized at the sublethal temperature of 48.deg.C in C. jejuni were thought to be responsible for thermotolerance. However, when C. jejuni cells heat-shocked at various ranges of sublethal and lethal temperatures were placed back to the optimum temperature of 42.deg.C, the multiplication patterns of the cells pretreated at different temperatures were not much different each other.

• 한국동물학회지
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• 제39권2호
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• pp.123-131
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• 1996

In this study, we examined the expression of heat shock proteins (HSPs) in fish cell line CHSE-2lnl and human HeLa cells exposed to heat shock. In fish CHSE-214 cells HSP70 was the major polvpeptide induced by an elevated temperature or an amino acid analog, while in HeLa cells HSP90 as well as HSP70 were prominently enhanced in response to these stresses. Pretreatment of actinomvcin D prior to heat shock completely inhibited the induction of fish HSP70, indicating the transcriptional regulation of fish HSP70 gene expression. In HeLa and CHSE-214 cells either recovering from heat shock or experiencing prolonged heat shock, attenuation in the HSP90 a'nd HSP70 induction occurred but both induction and repression of HSP70 synthesis appear 19 precede those of HSP90. Moreover, attenuation did not occur in the syntheses of 40 kDa and 42 kOto proteins which were only induced in CHSE-214 cells. The enhanced syntheses of these he proteins continued as long as CHSE-214 cells were Siven heat shock. These results suggest that down-regulation of HSP syntheses during prolonged heat shock may be controlled by several different. as vet undefined, mechanisms.

• Journal of Microbiology
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• 제39권3호
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• pp.162-167
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• 2001

Methylovorus sp. strain SS1 DSM 11726 was found to grow continuously when it was transferred from 30$\^{C}$ to 40$\^{C}$ and 43$\^{C}$. A shift in growth temperature from 30$\^{C}$ to 45$\^{C}$, 47$\^{C}$ and 50$\^{C}$ reduced the viability of the cell population by more than 10$^2$, 10$^3$and 10$\^$5/ folds, respectively, after 1h cultivation. Cells transferred to 47$\^{C}$ and 50$\^{C}$ after preincubation for 15 min at 43$\^{C}$, however, exhibited 10-fold increase in viability. It was found that incubation for 15 min at 40$\^{C}$ of Methylovorus sp. strain SSl grown at 30$\^{C}$ was sufficient to accelerate the synthesis of a specific subset of proteins. The major heat shock proteins had apparent molecular masses of 90, 70, 66, 60, and 58 kDA. The 60 and 58 kDa proteins were found to cross-react with the antiserum raised against GroEL protein. The heat shock response persisted for over 1h. The shock proteins were stable for 90 min in the cell. Exposure of the cells to methanol induced proteins identical to the heat shock proteins. Addition of ethanol induced a unique protein with a molecular mass of about 40 kDa in addition to the heat-induced proteins. The proteins induced in paraquat-treated cells were different from the heat shock proteins, except the 70 and 60 kDa proteins.

• BMB Reports
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• 제40권4호
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• pp.554-561
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• 2007

Shen and colleagues (Lin et al., 2004) have recently shown that overexpression of the Drosophila DNA methyltransferase 2 isoform C, dDnmt2c, extended life span of fruit flies, probably due to increased expression of small heat shock proteins such as Hsp22 or Hsp26. Here, I demonstrate with immunoprecipitations that overexpressed dDnmt2c interacts with endogenous Hsp70 protein in vivo in S2 cells. However, its C-terminal half, dDnmt2c(178-345) forms approximately 10-fold more Hsp70-containing protein complexe than wild-type dDnmt2c. Overexpressed dDnmt2c(178-345) but not the full length dDnmt2c is able to increase endogenous mRNA levels of the small heat shock proteins, Hsp26 and Hsp22. I provide evidence that dDnmt2c(178-345) increases Hsp26 promoter activity via two heat shock elements, HSE6 and HSE7. Simultaneously overexpressed Hsp40 or a dominant negative form of heat shock factor abrogates the dDnmt2c(178-345)-dependent increase in Hsp26 transcription. The data support a model in which the activation of heat shock factor normally found as an inactive monomer bound to chaperones is linked to the overexpressed C-terminus of dDnmt2c. Despite the differences observed in flies and S2 cells, these findings provide a possible explanation for the extended lifespan in dDnmt2c-overexpressing flies with increased levels of small heat shock proteins.

• 한국어병학회지
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• 제12권2호
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• pp.89-99
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• 1999

V. vulnificus ATCC 27562균주의 배양 온도를 $2^{\circ}C $, 20분간 및 6% 에탄올, 10분간으로 반응시켰을 때 SDS-PAGE상에서 새로운 16가지의 heat shock protein(hsps)과 10가지의 ethanol shock protein이 나타났다. Lethal temperature에 노출하기전에 미리 열 충격을 가한 경우 thermo tolerance가 유도되었다. 균체면역에 의해 생성된 항혈청과 열 충격 세포에서 분리된 막단백질과의 ELISA에서는 Outer Membrane Protein(OMP)에서 높은 면역반응을 나타냈으며 western blotting으로는 Inner Membrane Protein(IMP)에서는 62kDa, OMP에서는 69 kDa단백이 높은 면역원성을 나타냈다. ethanol 충격 반응에서는 IMP에서는 48 kDa, OMP에서는 오직 major밴드에서만 면역반응성이 확인되었다. anti-V, vulnificus혈청에 대한 균체 응집시험에서는 열 충격 반응 후의 균체가 정상 균체에 비해 응집반응성이 높았다.

• Mycobiology
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• 제43권3호
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• pp.272-279
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• 2015

To screen molecular chaperones similar to small heat shock proteins (sHsps), but without ${\alpha}$-crystalline domain, heat-stable proteins from Schizosaccharomyces pombe were analyzed by 2-dimensional electrophoresis and matrix assisted laser desorption/ionization time-of-flight mass spectrometry. Sixteen proteins were identified, and four recombinant proteins, including cofilin, NTF2, pyridoxin biosynthesis protein (Snz1) and Wos2 that has an ${\alpha}$-crystalline domain, were purified. Among these proteins, only Snz1 showed the anti-aggregation activity against thermal denaturation of citrate synthase. However, pre-heating of NTF2 and Wos2 at $70^{\circ}C$ for 30 min, efficiently prevented thermal aggregation of citrate synthase. These results indicate that Snz1 and NTF2 possess molecular chaperone activity similar to sHsps, even though there is no ${\alpha}$-crystalline domain in their sequences.

• The Plant Pathology Journal
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• 제31권4호
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• pp.323-333
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• 2015

As sessile organisms, plants are exposed to persistently changing stresses and have to be able to interpret and respond to them. The stresses, drought, salinity, chemicals, cold and hot temperatures, and various pathogen attacks have interconnected effects on plants, resulting in the disruption of protein homeostasis. Maintenance of proteins in their functional native conformations and preventing aggregation of non-native proteins are important for cell survival under stress. Heat shock proteins (HSPs) functioning as molecular chaperones are the key components responsible for protein folding, assembly, translocation, and degradation under stress conditions and in many normal cellular processes. Plants respond to pathogen invasion using two different innate immune responses mediated by pattern recognition receptors (PRRs) or resistance (R) proteins. HSPs play an indispensable role as molecular chaperones in the quality control of plasma membrane-resident PRRs and intracellular R proteins against potential invaders. Here, we specifically discuss the functional involvement of cytosolic and endoplasmic reticulum (ER) HSPs/chaperones in plant immunity to obtain an integrated understanding of the immune responses in plant cells.

• Genomics & Informatics
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• 제7권1호
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• pp.26-31
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• 2009

Heat shock proteins are a class of molecular chaperones that can be found in nearly all organisms from Bacteria, Archaea and Eukarya domains. Heat shock proteins experience increased transcription during periods of heat induced osmotic stress and are involved in protein disaggregation and refolding as part of a cell's danger signaling cascade. Heat shock protein, Hsp20 is a small molecular chaperone that is approximately 20kDa in weight and is hypothesized to prevent aggregation and denaturation. Hsp20 can be found in several strains of Proteobacteria, which comprises the largest phyla of the Bacteria domain and also contains several medically significant bacterial strains. Genomic analyses were performed to determine a common evolutionary pattern among Hsp20 sequences in Proteobacteria. It was found that Hsp20 shared a common ancestor within and among the five subclasses of Proteobacteria. This is readily apparent from the amount of sequence similarities within and between Hsp20 protein sequences as well as phylogenetic analysis of sequences from proteobacterial and non-proteobacterial species.

• 한국동물학회지
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• 제39권1호
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• pp.47-53
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• 1996

K562 백혈구암 세포의 phorbol 12-myristate 13-acetate(PMA)에 의한 대핵세포로의 분화과정에서 heat shock proteins(HSPs)와 glucose-regulated proteins(GRPs)의 발현을 조사하였다. PMA에 의한 K562 세포의 분화 특징은 세포성장의 억제, 형태학적 변화, gpllIa의 발현 증가, c-myc 발현의 감소 등으로 나타난다. PMA에 의한 대핵세포 분화과정에서, HSP90A, HSP90B 그리고 HSP28 mRNA와 단백질 합성은 현저히 감소하는 반면, GRP78/BiP와 GRP94의 mRNA 합성은 증가하였다. 한편 HSP7OA와 HSP7OB의 mRNA 합성은 감소하였지만, HSP70 단백질의 합성은 변함이 없었다. 이러한 결과는 HSPs와 GRPs가 K562 세포의 증식 또는 대핵세포 분화 과정에서 특이한 역할을 할 것임을 시사하고 있다.

• Journal of Microbiology
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• 제44권5호
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• pp.492-501
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• 2006

In this study, we attempted to characterize the physiological response to oxidative stress by heat shock in Saccharomyces cerevisiae KNU5377 (KNU5377) that ferments at a temperature of $40^{\circ}C$. The KNU5377 strain evidenced a very similar growth rate at $40^{\circ}C$ as was recorded under normal conditions. Unlike the laboratory strains of S. cerevisiae, the cell viability of KNU5377 was affected slightly under 2 hours of heat stress conditions at $43^{\circ}C$. KNU5377 evidenced a time-dependent increase in hydroperoxide levels, carbonyl contents, and malondialdehyde (MDA), which increased in the expression of a variety of cell rescue proteins containing Hsp104p, Ssap, Hsp30p, Sod1p, catalase, glutathione reductase, G6PDH, thioredoxin, thioredoxin peroxidase (Tsa1p), Adhp, Aldp, trehalose and glycogen at high temperature. Pma1/2p, Hsp90p and $H^+$-ATPase expression levels were reduced as the result of exposure to heat shock. With regard to cellular fatty acid composition, levels of unsaturated fatty acids (USFAs) were increased significantly at high temperatures ($43^{\circ}C$), and this was particularly true of oleic acid (C18:1). The results of this study indicated that oxidative stress as the result of heat shock may induce a more profound stimulation of trehalose, antioxidant enzymes, and heat shock proteins, as well as an increase in the USFAs ratios. This might contribute to cellular protective functions for the maintenance of cellular homeostasis, and may also contribute to membrane fluidity.