• The Korean Journal of Zoology
• /
• v.35 no.2
• /
• pp.203-210
• /
• 1992

Hsp70, a 70 kDa protein, is the maior protein expressed when cells are heat-shocked. A cDNA library from mouse ID13 cells was screened with the human hsp70 gene as a probe, and a positive clone was obtained. The positive clone was subcloned into puc19 and the precise restriction was obtained. The CDNA was sequenced by the Sanger's dideoxv termination method. Single open reading frame that codes for a protein of 70 kDa was found. The DNA sequence of the cloned mouse DNA shows great homology (66-90%) with other mouse hsp70 genes and somewhat less homology (50",) with E. coli hsp70 gene (dnak). With the exception of one amino acid, the protein sequence deduced from the CDNA is identical to the mouse that shock cognate protein 70 (hsc70) that is constitutivelv expressed at normal temperature. The result suggests that the cloned CDNA encodes a hsc70 family rather than a heatinducible family.mily.

• Molecules and Cells
• /
• v.20 no.2
• /
• pp.173-182
• /
• 2005

Heat shock protein gp96 is an endoplasmic reticulum chaperone, belonging to the HSP90 family. The function of gp96 as a molecular chaperone was discovered more than 10 years ago, but its importance has been overshadowed by the brilliance of its role in immune responses. It is now clear that gp96 is instrumental in the initiation of both the innate and adaptive immunity. Recently, the roles of gp96 in protein homeostasis, as well as in cell differentiation and development, are beginning to draw more attention due to rapid development in the structural study of HSP90 and some surprising new discoveries from genetic studies of gp96. In this review, we focus on the aspect of gp96 as an ER molecular chaperone in protein maturation, peptide binding and the regulation of its activity.

• The Plant Pathology Journal
• /
• v.31 no.4
• /
• pp.323-333
• /
• 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.

• Proceedings of the Korean Society of Grassland Science Conference
• /
• 2005.06a
• /
• pp.214-215
• /
• 2005

• Journal of Life Science
• /
• v.7 no.4
• /
• pp.276-281
• /
• 1997

This study was investigated to determine whether nicotine causes the morphological changes and expression of heat shock protein(HSP) 70 in the central nervous system of rat embryo. The pregnant rats were injected s.c. twice daily with 3 mg nicotine per 100g body weight from day 0 to 14 of gestation and embryos were removed on gestation day 15. As morphological changes, retardation of cell proliferaton was observed in the telencephalon of nicotine-treated groups and no changes in the other region were found. Minimal HSP 70 was expressed over chole central nervous system was similar between control and nicotine-treated group, the expression of blood cells in the meinges and chroid plexus was significantly greater in nicotine-treated group than in control.

• Korean Journal of Microbiology
• /
• v.32 no.1
• /
• pp.47-52
• /
• 1994

The cells of Campylobacter jejuni heat-shocked at 48${\circ}C$ for 30 min synthesized the heat shock proteins of HSP90, HSP66 and HSP60. Those heat shock proteins were found to correspond to the heat shock proteins of HSP87, HSP66 (DnaK), and HSP58 (GroEL) of E. coli, respectively. By Southern blot analysis of the chromosomal DNAs of C. jejuni with groESL and dnaK genes of E. coli as DNA probes, the heat shock genes of C. jejuni which are homologous to the E. coli groESL and dnaK genes were found to exist in the chromosomal DNA. The genomic libraries of C. jejuni were constructed with the cosmid vector pWE15 and the groEL gene of C. jejuni were cloned in E. coli B178 groEL44 temperature senstive mutant. The hybrid plasmid (pLC1) was inserted with the DNA fragment (about 5.7kb in size) containing the groEL gene. E. coli groEL44 mutant cell transformed with the pLC1 could grow at 42${\circ}C$ by synthesizing the HSP60 of C. jejuni and regained the susceptibility to the ${\lambda}$ vir phage by expression of the groEL gene in the cloned cells. These indicated that the groEL products of C. jejuni had chaperon effects by synthesizing the heat shock proteins in the cloned cells of E. coli.

• The Korean Journal of Zoology
• /
• v.26 no.3
• /
• pp.155-170
• /
• 1983

The primary concern has been focused on the response and adaptation of mouse fibroblast tumor cells to heat-shock in the level of membrane surface proteins, using two labeling techniques, lactoperoxidase-catalyzed iodination and galactose oxidase-sodium borohydride. Cells arrested in $G_1$ phase exhibited the highest level of LETS protein and high molecular proteins than did cells passing through $G_1/S, S, G_2$ and M, and unsynchronized cells. Confluent cells were found to show an increase in 125K proteins and a decrease in 130K and 100K proteins selectively. The adaptation processes of tumor cells after heat-shock were observed. All the proteins above 80K were reduced immediately after heat-shock, whereas 70K protein increased markedly 24 hours after heat-shock. The 70K protein and high molecular proteins returned to normal level in 48 hours. The 70K protein was found to be trypsin-sensitive and was similarly labeled by galactose-oxidase as well as by lactoperoxidase. It was, therefore, concluded that 70K protein is glycoprotein located on the surface membrane and might be the HSP 70. Possible function of heat-shock protein on the surface membrane and the relation of this protein to differential heat-sensitivity of tumor cells are discussed.

• Korean Journal of Veterinary Research
• /
• v.24 no.1
• /
• pp.40-49
• /
• 1984

To investigate the factors influencing the artifical transformation in Escherichia coli, E. coli C600 was transformed by pBR322 DNA with tetracycline and ampicillin resistant gene purified by CsCl-Etbr equilibrium density gradient centrifugation from E.coli HB 101. The influencing factors in the transformation such as concentration of calcium chloride, time of ice incubation, temperature and time of heat shock, time of gene expression, effects of plasmid DNA concentration and adding time were examined in these experiments. The results obtained were as follows; 1. The highest transformation frequency was observed in the treatments of 100 mM $CaCl_2$ before heat shock and the treatment of $CaCl_2$ was essential step in the process of E. coli transformation. 2. The highest transformation frequency was observed in the treatment of heat shock at $42^{\circ}C$ for 4 min. or $37^{\circ}C$ for 6 min., but the prolonged heat shock resulted a decreased transformation frequency. 3. Treatments of ice incubation at $0^{\circ}C$ for 45 min. before heat stocks or at $0^{\circ}C$ for 30min. after heat shock resulted an increased transformation frequency. 4. There was a linear relationship between DNA concentration and transformation frequency at the concentration of $8{\times}10^3$ recipient cells. The highest transformation frequency reached in carte of 7 mcg of donor DNA, but above 1 mcg of DNA concentration, transformation frequency was not remarkably increased. Addition of donor DNA just after the treatment of $CaCl_2$ was the best. 5. The best condition of gene expression at $37^{\circ}C$ were 40min. for TC-resistant gene and 100min. for AP-resistant gene. TC-resistant gene was higher in the transformation frequency and faster in the gene expression time than AP-resistant gene. In these results, the best conditions for the transformation of E. coli C 600 with pBR322 DNA were: treatment with 100mM $CaCl_2$, ice incubation at $0^{\circ}C$ for 45 min, heat shock at $42^{\circ}C$ for 4 min., 30 min. of ice incubation and incubation at $37^{\circ}C$ for 100min. for gene expression in that order.

• Journal of Aquaculture
• /
• v.12 no.3
• /
• pp.175-183
• /
• 1999

We have shown previously that the sequence of olive flounder (Paralichthys olivaceus) hsp70-related cDAN has a high similarity with those of cognate hsc70 of other species (Kim et al., 1999; J. Aquaculture, 12:91-100). In order to investigate whether this gene encodes the congate hsc70, we examined the expression of this gene in normal and heat-shocked conditions. By in vitro translation, this gene encoded a 70 kD protein which was constitutively experessed and was not induced by heat shock. This translated protein was recognized by anti-hsp/hsc70 antibody. Tests of heat-inducibility showed that this gene was constitutively expressed in normal conditions and its expression was not increased after heat shock. The expression levels of this gene were high in stomach, gill, intestine, kidney and brain, moderate in liver, and comparatively low in overy and heart. Furthermore, Northern blot analysis of transcript expression showed that the corresponding mRNA were detected throughout embryonic development in the absence of any heat shock. These results provided evidence that olive flounder hsp70-related cDNA encoded to cognate member of hsp70 family, hsc70.

• Proceedings of the Microbiological Society of Korea Conference
• /
• 2005.05a
• /
• pp.105-109
• /
• 2005

Heat Shock Transcription Factor (HSF), and the promoter heat Shock Element (HSE), are among the most highly conserved transcriptional regulatory elements in nature. HSF mediates the transcriptional response of eukaryotic cells to heat, infection and inflammation, pharmacological agents, and other stresses. While HSF is essential for cell viability in yeast, oogenesis and early development in Drosophila, extended life-span in C. elegans, and extra-embryonic development and stress resistance in mammals, little is known about its full range of biological target genes. We used whole genome analyses to identify virtually all of the direct transcriptional targets of yeast HSF, representing nearly three percent of the genomic loci. The majority of the identified loci are heat-inducibly bound by yeast HSF, and the target genes encode proteins that have a broad range of biological functions including protein folding and degradation, energy generation, protein secretion, maintenance of cell integrity, small molecule transport, cell signaling, and transcription. Approximately 30% of the HSF direct target genes are also induced by the diauxic shift, in which glucose levels begin to be depleted. We demonstrate that phosphorylation of HSF by Snf1 kinase is responsible for expression of a subset of HSF targets upon glucose starvation.