• The Korean Journal of Zoology
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• v.36 no.4
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• pp.487-495
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• 1993

TRH (Thvrotropin-Releasing Hormone) known to regulate the transcription of the TSH (Thyroid-Stimulating Hormones gene in pituitary cells, but little is understood about the mechanism(sl involved. re present study was attempted to elucidate the role of Ca2+ movement through the voltage-gated channels in the regulation of TSH gene transcription. The c-fos is one of immediate early genes and used as model system for the investigation of signaling pathwavs involved in various stimuli. The changes of c-fos mRNA levels were determined after treatment of various agents using Northern and slot hybridization analysis. The c-fos mRNA was rapidly and transiently induced by TRH (about 3-fold) in GH3 cells and this induction was repressed by calcium chelating agent (EGTA), calcium channel blocker (verapamil) anti protein kinase C inhibitor (aminoacridine). The abilities of forskolin (adenvlate cvclase activators, PMA (protein kinase C activator), and A23187 (calcium ionophore) to affect c-ios gene transcription, either alone or in combination with TRH were tested in the same cells. All of them significantly increased the level of c-fos mRUA. However, no additive relationship was observed in all combined treatments except forskolin. These results suggest that TRH action on the c-fos gene activation is mediated by calcium influx as well as through protein kinase C.

• Journal of Life Science
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• v.14 no.2
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• pp.255-262
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• 2004

We applied nuclear DNA content stained with 4'-6'-diamidino-2-phenylindole (DAPI) and total protein concentration to predict the existence of Cochlodinium polykrikoides before huge blooms occurred, based on a short-term survey at sites in the South Sea. Fluctuations in environmental conditions and nutrients (nitrate, nitrite, and phosphate) were of a similar range, regardless of sampling sites or early and middle field observations. However, C. polykrikoides abundance was significantly different depending on the station, with a higher cell density of 34, 62, and 57 cells L$^{-1}$ at Stn C2, C5, and C6, respectively than what was found in early August, 2000. In mid August, 2000, the highest cell density of 547 cells L$^{-1}$ at Stn C3 was observed. The relationship between C. polykrikoides abundance, DAPI-stained DNA content, and total protein concentration was a positive correlation coefficient, in particular a higher positive correlation was exposed to even a smaller abundance of C. polykrikoides. These results suggest that DNA stained by DAPI and total protein concentration could play an important index in easily predicting the presence of C. polykrikoides before blooms.

• Bulletin of the Korean Chemical Society
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• v.19 no.3
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• pp.295-299
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• 1998

HSP104 protein in Saccharomyces cerevisiae is known to provide thermotolerance when induced by various kinds of stresses, such as a mild heat shock, ethanol, and hypoxia. It helps cells survive at an otherwise lethal temperature. Mechanisms by which HSP104 protein works are yet to be elucidated. In order to understand a molecular basis of thermotolerance due to HSP104 protein induced by a mild heat shock, studies on respiratory pathways were carried out in the wild type as well as in the hsp104 deleted mutant. Especially the degree of 13C-acetate incorporation into glutamate-C4 was examined for both strains using 13C-13C homonuclear spin coupling measurements, since glutamate is in a rapid equilibrium with α-ketoglutarate in the TCA cycle. In addition, the temperature effects on the rate of 13C incorporation are compared with or without HSP104 protein expressed. Finally, the inhibitory effect of HSP104 on the respiration pathway was confirmed by the measurements of oxygen consumption rates for both strains.

• BMB Reports
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• v.30 no.3
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• pp.222-228
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• 1997

Protein phosphatase 2C (PP2C) is one of the four major serine/threonine phosphatases which is dependent on $Mg^{2+}$ for its activity. PP2C was purified from rat liver cytosol and its characteristics were investigated. The substrate employed for routine assay was $[^{32}P]casein$ phosphorylated by PKA. The purification process involved DEAE chromatography, ammonium sulfate fractionation, phenyl sepharose chromatography, sephacryl 5-200 gel filtration, and histone agarose chromatography. The SDS-PAGE of PP2C showed one major single protein band at a position corresponding to a molecular mass of 43 kd and the purification fold was 637. The enzyme showed a pH optimum of 8 and $K_M$ value was $1.9\;{\mu}M$. However, when the substrate was changed to $[^{32}P]histone$, the pH optimum was shifted to 7 and $K_M$ value was $2.3\;{\mu}M.\;Mg^{2+}$ was essential to the enzyme activity and okadaic acid did not exert any inhibitory effect on the enzyme. To examine residue in the active site of PP2C effects of some protein-modifying reagents were tested.

• Journal of Industrial Technology
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• v.28 no.B
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• pp.59-63
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• 2008

Rapid production of therapeutic proteins such as angiostatin and endostatin angiogenic inhibititors has been highly demanded for cancer treatment. In this regard, recombinant human angiostatin and endostatin were successfully expressed as soluble forms by maltose binding protein (MBP)-mediated fusion expression in Escherichia coli. PCR amplified, angiostatin and endostatin genes from human placenta cDNA library were inserted into an expression vector pMAL-c2e to construct prokaryotic expression vectors, pMAL-c2e/AS and pMAL-c2e/ES, respectively. Recombinant angiostatin and endostatin were efficiently expressed in E. coli origami (DE3) after IPTG induction and protein expression were confirmed by SDS-PAGE analyses. The expressed recombinant proteins were purified near homogenity using an amylose affinty column chromatography. In contrast that previous E. coli expressions were all insoluble, our results first time demonstrated that MBP fused human angiostatin and endostatin were soluble in E. coli.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.1
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• pp.69-73
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• 1992

Two experiments were conducted with one-day-old straight run Muscovy ducklings to determine their protein and energy requirements. In the 1st experiment, isoenergetic diets (2800 kcal ME/kg) with three dietary proteins, 18, 20 and 22% in the starter period (1-28 days) and 16, 18 and 20% in the grower and finisher period (29-84 days) were used to determine the optimum protein requirement. While, in the 2nd experiment, isonitrogenous diets (20%, C.P.) with three dietary energy, 2700, 2800 and 2900 kcal ME/kg in the starter period (1-28 days) and (18% C.P.) with 2800, 2900 and 3000 kcal ME/kg in the grower-finisher period (29-84 days) were used to determine the optimum energy requirement. It was observed that 20% C.P. in the starter period and 18% C.P. in the grower and finisher period was adequate for optimum performance, while, 2900 kal ME/kg was sufficient to meet the optimum energy requirement in both the starter, grower-finisher period as regards body weight, feed efficiency, protein efficiency and caloric efficiency are concerned.

• Microbiology and Biotechnology Letters
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• v.18 no.5
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• pp.541-546
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• 1990

Bacillus sphaericus ts-Dl290 was characterized by SDS-PAGE produced by the mutant at $30^{\circ}C$ and $42^{\circ}C$. The total amount of proteins produced by the mutant at $42^{\circ}C$ decreased to one-fifth of those at $30^{\circ}C$; however, when the culture was shifted down from $42^{\circ}C$ after 4 to $30^{\circ}C$, the total amount of protein decreased to one-third and the 221 kd protein did not appear, but the 155 kd appeared remarkably. When the mutant and the wild type strain were cultured in the media containing 80$\mu g$ per ml of chloramphenicol at $42^{\circ}C$, the wild type strain synthesized half amounts of the total proteins than those at $30^{\circ}C$, and the mutant produced one-tenth of the total protein amounts. When the both strains were cultured in the media containing chloramphenicol, the 155 kd protein was produced was produced in lesser amounts than those without chloramphenicol. The 150 kd protein showed lethal activity to Culex pipiens 3rd instar larvae.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2008.11a
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• pp.538-544
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• 2008

Activated protein C (APC) is thought to exert antiinflammatory activities through the endothelial protein C receptor (EPCR)-dependent cleavage of protease activated receptor 1 (PAR-1) in endothelial cells. Since thrombin cleaves PAR-1 with $\sim$3-4-orders of magnitude higher efficiency, and PAR-1 is a target for proinflammatory activities of thrombin, it is not understood how APC can elicit protective responses through the cleavage of PAR-1. In this study, we demonstrate that EPCR is associated with caveolin-1 in endothelial lipid rafts, but its occupancy by protein C leads to its dissociation from caveolin-1 and subsequent recruitment of PAR-1 to protective signaling pathways through the coupling of PAR-1 to Gi-protein. When EPCR is bound by protein C, the PAR-1-dependent protective response in endothelial cells can be mediated by either thrombin or APC. These results provide a new paradigm for understanding the mechanism through which PAR-1 and EPCR participate in cellular signaling events in endothelial cells.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.8
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• pp.1148-1156
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• 2011

Compensatory growth of juvenile olive flounder Paralichthys olivaceus fed different diets with different feeding regime was compared. Four hundred fifty fish (twenty five fish per tank) were randomly distributed into 18 of 180 L flow-through tanks. Six treatments were prepared: fish were hand-fed with the control (C) diet to satiation twice a day, six days a week, for 8 weeks (C-8W treatment); and other groups of fish were starved for 2 weeks and then fed with the C, high protein (HP), high carbohydrate (HC), high lipid (HL), and combined protein, carbohydrate and lipid (CPCL) diets to satiation twice a day, six days a week, for 6 weeks, referred to as C-6W, HP-6W, HC-6W, HL-6W, and CPCL-6W treatments, respectively. Final body weight of fish in HP-6W treatment was higher than that of fish in C-6W, but not different from that of fish in C-8W, HC-6W, HL-6W and CPCL-6W treatments. Specific growth rate of fish in HP-6W treatment was higher than that of fish in all other treatments except for fish in CPCL-6W treatment. Feeding rate of fish in C-8W treatment was higher than that of fish in HP-6W, HC-6W, HL-6W and CPCL-6W treatments, but not different from that of fish in C-6W treatment. In addition, feeding rate of fish in C-6W treatment was higher than that of fish in HP-6W, HL-6W and CPCL-6W treatments. Feed and protein efficiency ratios of fish in HP-6W, HC-6W, HL-6W and CPCL-6W treatments were higher than those of fish in C-6W treatment. None of moisture, crude protein and ash content of the whole body of fish excluding the liver was different among treatments. Dietary supplementation of protein, carbohydrate, lipid and their combination could improve compensatory growth of fish when fish were fed for 6 weeks after 2-week feed deprivation; especially, supplementation of dietary protein was the most effective to improve compensatory growth of fish.

• Journal of Ginseng Research
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• v.22 no.2
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• pp.133-139
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• 1998

We have studied an activation mechanism of $pp60^{c-src}$ protein tyroslne kinase (PTK) by ginsenoside-$Rg_1$ (G-$Rg_1$ ) in NIH(pMcsrc/foc)B c-src overexpressor cells. It was previously reported that G--$Rg_1$ stimulated the activation of c-src kinase at 20 pM with a 18 hr-incubation, increasing the activity by 2-4-fold over that of untreated control, and this effect was blocked by treatments of in- hibitors of either protein synthesis (cycloheximide) or RNA synthesis (actinomycin D) (Hong, H.Y. et at. Arch. Pharm. Res. 16, 114 (1993)). However, an amount of c-src protein itself in wild-type cells was not changed by G-$Rg_1$. When the cells mutated at one or two tyrosine residue(s) (Y416/527) that are important sites to regulate the kinase activity were treated with G-$Rg_1$, increases both in the activity of c-src kinase and in the expression of the protein were not observed. In addition, removal of extracellular calcium ion by EGTA or inhibition of PKC by H-7 canceled the G-$Rg_1$-induced activation of the kinase. Although the activation was little affected by G-$Rg_1$ with a calcium ionophore A23187, it was synergistically stimulated by treatment of G-Rgl and PMA, a PKC activator. Taken together, these results suggest that the activation of c-src kinase by G-$Rg_1$ is caused by an increase in the specific activity of the kinase, but not in amount of it, and is involved with both collular calcium ion and PKC. Further the increase in the specific activity of c-src kinase may result from altered phosphorylation at tyro-416 and -527.