• Journal of Microbiology
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• 제34권3호
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• pp.263-263
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• 1996

Infection of fish cells with IHNV resulted in gradual increase in cytosolic free $Ca^{2+}$ concentration $([Ca^{2+}]_i)$ in CHSE, gradual decrease in $[Ca^{2+}]_i$ in FHM, and no significant change in RTG cells. The degree of $[Ca^{2+}]_i$ increase or decrease was dependent on the amount of infectious virus, and these $[Ca^{2+}]_i$ variations were maximal at 16 hours after virus infection (p. i.) in both cell lines. When the fish cells were infected with inactivated IHNV, evident variation in $[Ca^{2+}]_i$ was not observed. Thus, infectivity of IHNV appears to correlate with changes in $[Ca^{2+}]_i$ in virus-infected cells. These IHNV-induced $[Ca^{2+}]_i$ changes were partially blocked by cycloheximide, but not affected by cordycepin. It seems to be that virus-induced $Ca^{2+}$ variations were more related with protein synthesis than RNA synthesis. Various $Ca^{2+}$ related drugs were used in search for the mechanisms of the $[Ca^{2+}]_i$, changes following IHNV infection of CHSE cells. Decreasing extracellular $Ca^{2+}$ concentration or blocking $Ca^{2+}$ influx from extracellular media inhibited the IHNV-induced increase in $[Ca^{2+}]_i$, in CHSE cells. Similar results were obtained with intracellular $Ca^{2+}$ blockers. Thus it is suggested that both the extracellular and the intracellular $Ca^{2+}$ sources are important in IHNV-induced $[Ca^{2+}]_i$ increase in CHSE cells.

• 한국환경농학회지
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• 제20권5호
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• pp.310-316
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• 2001

To find out the effect of low temperature on the regulation of tomato chloroplast genes, the optimization of the system in chloroplast protein synthesis and the identification of the changes in chloroplast protein synthesis induced by chilling were studied. Incorporation reaction occurred rapidly at the first 30 minutes and was constantly maintained after 60 minutes. A broad optimal temperature on protein synthesis was found around 20 to $30^{\circ}C$. No difference was shown in the chloroplast protein synthesis under high light intensity (1600 ${\mu}E/m^2/s$) as well as under low light intensity (400 ${\mu}E/m^2/s$) even darkness. $K^+$, $Mg^{++}$ and ATP at an optimal concentration act as an activator, while DTT, chloramphenicol, cycloheximide, $Ca^{++}$ and inorganic phosphate act as an inhibitor in the chloroplast protein synthesis. Synthesis of 15, 55 and 60 kd chloroplast encoded stromal proteins and 18, 24, 33 and 55 kd chloroplast encoded thylakoid membrane proteins were reduced by chilling, while 17 kd chloroplast encoded stromal protein and 16 kd chloroplast encoded thylakoid membrane protein was induced by chilling. It was expected that the 55 kd stromal protein would be the large subunit of rubisco and the 33 kd thylakoid membrane protein would be the D1 protein which was drastically reduced by chilling.

• Food Science and Biotechnology
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• 제14권5호
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• pp.593-598
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• 2005

Osteoporosis is recognized as one of the major hormonal deficiency diseases, especially in menopausal women and the elderly. When the estrogen level is reduced in the body, local factors, which are known to be related with bone resorption, are increased and promote osteoclastogenesis. In our previous study, we validated the estrogenicity of silkworm pupa. In this study, we investigated the effect of silkworm pupa extract (SPE) on the function of osteoblastic MC3T3-E1 cells. SPE (10 and $50\;{\mu}g/mL$) significantly elevated cell viability, alkaline phosphatase (ALP) activity, and collagen content in the cells. The effect of SPE ($50\;{\mu}g/mL$) in increasing cell viability, ALP activity, and collagen content was completely inhibited by the presence of $10^{-6}\;M$ of cycloheximide and $10^{-6}\;M$ of tamoxifen, suggesting that SPE's effect results from a newly synthesized, protein component and that it might be partly involved in estrogen action. Furthermore, we examined the effect of SPE on the $H_2O_2-induced$ apoptosis and production of local factors in osteoblasts. Treatment with SPE ($50\;{\mu}g/mL$) decreased the 0.2 mM $H_2O_2-induced$ apoptosis and the production of tumor necrosis factor (TNF)-${\alpha}$, interleukin (IL)-6 and nitric oxide (NO) in osteoblasts. Our data indicate that the enhancement of osteoblast function by silkworm pupa may prevent osteoporosis and inflammatory bone diseases.

• Journal of Microbiology
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• 제34권1호
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• pp.37-37
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• 1996

The internal regions of nuclear small subunit rRNA from 6 plaeurotus species and 5 Pleurotus ostreatus strains were amplified by PCR and sequenced. The DNA sequences of 8 Pleurotus strains (P. ostreatus NFFA2, NFFA4501, NFFA4001, KFFA4001, KFCC11635, P florida, P. florida, P. sajor-cuju, P. pulmonarius, and P. spodoleucus) were idential, but P. cornucopiae differed from them in two bases out of 605 bases. However, p[hylogenetic analysis of the sequences by DNA-distance matrix and UPGMA methods showed that P. ostreatus NFFA2m1 and NFFA2m2, known as mutants of P. ostreatus NFFA2, belonged to anther group of Basidiomycotina, which is close to the genus Auricularia. The difference of the SSU rDNA sequences of P. cornucopiae from other Pleurotus species tested corresponds to the difference of mitochondrial plasmid type present in Pleurotus species as observed by Kim et al. (1993, Korean J. Microbiol. 31, 141-147).ishement of silencing at the HMR/hsp82 locus can occur in G1-arrested cells. Cell cycle arrest at G1 phase was achieved by treatment of early log a cell cultures with .alpha.-factor mating pheromone, which induces G1 arrest. The result suggests that passage through S phase (and therefore DNA replication) is nor required for re-establishing silencer-mediated repression at the HMNRa/HSP82 locus. Finally, to test whether de nono protein synthesis is required for re-establishment of silencer-mediated repression, cells were pretreated with cycloheximide (500 /.mu.g/ml) 120 min. It was apparent that inhibiting protein synthesis delays, but does not prevent, re-establishment of silencer-mediated repression. Altogether, these results indicate that re-establishment of silencer-mediated repression is not dependent on the DNA replication and has no requirement for protein synthesis.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2001년도 발생공학 국제심포지움 및 학술대회 발표자료집
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• pp.62-62
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• 2001

Development of effective activation protocols is of great importance for improving the success of cloning and subsequent transgenic. Three methods for oocyte activation, including 5μM ionomycin (5 min) alone, ionomycin＋1.9 mM 6-dimetylaminopurine (DMAP, 3 hrs) and ionomycin＋10㎍/㎖ cycloheximide(CHX, 3 hrs) were compared for their effects of pronuclei(PN) formation, development, developmental velocity and ploidy of parthenotes to IVF control in bovine. In group of ionomycin＋DMAP, the oocytes having more 3 PN were significantly(P〈0.05) higher than in groups of ionomycin alone and of ionomycin＋CHX (45.5% vs. 0 and 0%, respectively). Activation with the ionomycin alone, ionomycin＋DMAP and ionomycin＋CHX resulted in cleavage rates of 30, 85.5 and 57.9%, respectively. The blastocysts rate of parthenotes activated by ionomycin＋DMAP treatment was significantly higher (12.3%, P〈0.05) than those of other treated groups. Chromosome analysis shows that ionomycin＋DMAP treatment greatly increases the incidence of chromosomal abnormality of the parthenotes. When compared the developmental velocity at 24 hrs after insemination and activation, 27% eggs in IVF control and 55% in DMAP treatment out of total cleaved eggs developed to 2-cell stage, respectively. Developmental velocity of parthenotes activated by ionomycin ＋DMAP treatment was significantly (P〈0.05) faster than others. From the results, we may conclude that DMAP treatment to the oocytes accelerates developmental velocity resulting in both the higher incidence of chromosome abnormality and of PN formation suggesting that CHX combined with ionomycin is suitable DMAP for the purpose of successful nuclear transplantation.

• Journal of Ginseng Research
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• 제22권2호
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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.

• 한국균학회지
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• 제14권1호
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• pp.43-47
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• 1986

리그닌과 관련된 대표적인 페놀화합물인 ferulic acid, vanillic acid 및 gallic acid와 단백질합성저해항생제인 cycloheximide와 puromycine 중에서 Lentinus edodes JA01 경우는 gallic acid가 Pleurotus ostreatus는 ferulic acid가 각각 가장 효과적인 inducer였다. gallic acid는 2.0mM에서, ferulic acid는 1.0mM에서 induction이 가장 잘 되었다. Inducer의 처리시기는 접종후 L. edodes는 2일후에, 그리고 P. ostreatus는 3일후에 최고의 활성을 나타내었다. 또한 polyphenol oxidase activity는 균주의 생장곡선에 대체적으로 비례하여 증가하였으나, P. ostreatus 경우는 대수기에서 최고의 활성을 나타내고 그 이후 감소하였다.

• 미생물학회지
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• 제36권4호
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• pp.306-311
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• 2000

Herpes simplex virus type-1 (HSV-1)의 감염에 따른 세포내 유리 칼슘농도의 변화에 대한 실험을 수행한 결과, HSV-1이 Vero 세포에 감염한 후 4시간째에 세포내 칼슘농도가 최대로 감소한 것을 알았으며 이러한 세포내 유리 칼슘농도의 감소는 감염성 바이러스의 양에 따라 커지며, 유전자 발현 억제제의 처리나 바이러스의 불활성화에 의해 극복되었다. 따라서 바이러스의 유전자발현이 세포내 유리 칼슘농도의 감소에 중요한 역할을 한다는 것을 알 수 있다. 또한 Vero 세포에 바이러스를 감염시키고 미세소관 안정제인 taxol을 처리하여 4 시간째의 세포내 유리 칼슘농도의 감소가 극복된다는 사실로부터 바이러스이 유전자 물질의 이동에는 미세소관이 관여한다는 것을 알 수 있었다. 이와 같은 실험 결과로부터 Vero 세포에서 HSV-1에 의해 유도되는 세포내 유리칼슘 농도의 감소는 HSV-1 증식과 밀접한 관계를 가진다고 생각된다.

• 한국동물학회지
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• 제31권3호
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• pp.157-164
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• 1988

SCK종양세포에 온열처리와 여러가지 sulihydryl-reacting agents을 처리하여 stress protein의 합성을 유도하고, 그 양상을 검토해 봄으로서 stress proteins의 합성유도와 denatured protein의 생성과의 관계를 고찰하였다. 세포에 cycloximid와 더불어 Zn또는 ME를 처리한 경우에는 stress protein의 합성이 일어나지 않았으나,온열처리 또는 IAA를 처리한 경우에는 stress protein의 합성이 유도되었다. 이 결과로 미루어 볼 때,stress protein의 유도 경로에는 두 가지가 있어서 새로운 단백질의 합성이 필요한 경로와 새로운 단백질의 합성과는 무관한 경로가 있는 것으로 추정할 수 있었다. 결국, 본 실험에서 사용한 stress들이 기존의 mature protein을 denature시키거나 (온열처리 또는 IAA),새로 합성된 immature protein을 denatur시키는 것,(Zn 또는 ME)으로 알려져 있으므로,stress에 의한 abnormal protein의 출현이 stress proteins의 합성을 유도하는 tigger의 구실을 하는 것으로 생각된다. 이 밖에 여러 가지 stress가 동시에 작용할 경우, 세포는 보다 강한 stress에 대해서 stress protein을 합성하여 대치하게 되는 것으로 생각된다.

• Archives of Pharmacal Research
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• 제20권3호
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• pp.212-217
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• 1997

Induction of an adaptive response to ionizing radiation in mouse lymphoma (EL4) cells was studied by using cell survival fraction and apoptotic nucleosomal DNA fragmentation as biological end points. Cells in early log phase were pre-exposed to low dose of ${\gamma}$-rays (0.01 Gy) 4 or 20 hrs prior to high dose ${\gamma}$-ray (4, 8 and 12 Gy for cell survival fraction analysis; 8 Gy for DNA fragmentation analysis) irradiation. Then cell survival fractions and the extent of DNA fragmentation were measured. Significant adaptive response, increase in cell survival fraction and decrease in the extent of DNA fragmentation were induced when low and high dose .gamma.-ray irradiation time interval was 4 hr. Addition of protein or RNA synthesis inhibitor, cycloheximide or 5,6-dichloro-1-.betha.-d-ribofuranosylbenzimidazole (DRFB), respectively during adaptation period, the period from low dose ${\gamma}$-ray irradiation to high dose ${\gamma}$-ray irradiation, was able to inhibit the induction of adaptive response, which is the reduction of the extent DNA fragmentation in irradiated EL4 cells. These data suggest that the induction of adaptive response to ionizing radiation in EL4 cells required both protein and RNA synthesis.