• Molecules and Cells
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• v.23 no.2
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• pp.239-245
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• 2007

DnaK is a major antigen in Streptococcus pneumoniae, and is induced by a minor shift in temperature (30 to $37^{\circ}C$) but not by ethanol shock. Although HrcA in the presence of $Ca^{{+}{+}}$ represses the expression of both groEL and hrcA, the control of transcription of the dnaK operon is not completely understood. In this study, the dnaK operon of S. pneumoniae (5' hrcA-grpE-dnaK-dnaJ) was cloned and analyzed. It contains large intergenic regions in grpE/dnaK and dnaK/dnaJ. Pulse labeling with [$^{35}S$]-methionine and immunoblot analyses revealed the presence of higher levels of DnaK than of HrcA even in the presence of $Ca^{{+}{+}}$ after heat shock suggesting that $Ca^{{+}{+}}$ differentially regulates the heat shock responses of hrcA and dnaK. By blocking de novo mRNA synthesis with rifampin it was shown that neither the hrcA nor the groEL transcripts were stabilized by heat shock even though dnaK transcripts were stabilized. We conclude that S. pneumoniae uses fine regulation of the transcription of the individual genes of the tetracistronic dnaK operon to cope with the various stresses experienced during infections.

• Current Applied Physics
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• v.18 no.11
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• pp.1294-1299
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• 2018

In this paper, we demonstrate the feasibility of constructing DNA nanostructures (i.e. DNA rings and double-crossover (DX) DNA lattices) with appropriate doxorubicin hydrochloride (DOX) concentration and reveal significant characteristics for specific applications, especially in the fields of biophysics, biochemistry and medicine. DOX-intercalated DNA rings and DX DNA lattices are fabricated on a given substrate using the substrateassisted growth method. For both DNA rings and DX DNA lattices, phase transitions from crystalline to amorphous, observed using atomic force microscopy (AFM) occurred above a certain concentration of DOX (at a critical concentration of DOX, $30{\mu}M$ of $[DOX]_C$) at a fixed DNA concentration. Additionally, the coverage percentage of DNA nanostructures on a given substrate is discussed in order to understand the crystal growth mechanism during the course of annealing. Lastly, we address the significance of optical absorption and photoluminescence characteristics for determining the appropriate DOX binding to DNA molecules and the energy transfer between DOX and DNA, respectively. Both measurements provide evidence of DOX doping and $[DOX]_C$ in DNA nanostructures.

• Korean Journal of Pharmacognosy
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• v.24 no.2
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• pp.159-165
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• 1993

The studies were conducted to investigate the effect of Sinhyo-Taklee-San(STS), which is composed of Astragali Radix(AR), Lonicerae Flos(LF), Angelicae gigantis Radix(AGR) and Glycyrrhizae Radix(GR), on the proliferation of fibroblast cell(Balb/c 3T3). STS, GR and glycyrrhizin increased the proliferation of 3T3 cells. The 10% serum obtained from STS, AR, LF, AGR and GR treated mice also increased the proliferation of 3T3 cells markedly. GR, glycyrrhizin and glycyrrhetinic acid inhibited protein synthesis, but did not affect on DNA synthesis.

• Korean Journal of Microbiology
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• v.25 no.2
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• pp.103-109
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• 1987

An ozone-sensitive mutant of Escherichia coli strain B, MQ 1844 is described. Its properties, including high sensitivity to ozone and radiation, inducible filamentation, extensive DNA degradation and impaired DNA synthesis following ozonation, are attributable to a mutation in ozrB, a gene which is cotransducible with malB. Based on differences in phenotypic expression as well as on the particular location of this gene on the bacterial chromosome, ozrB appears as distinct from the other ozone-or radiation-sensitivity genes previously described.

• Bulletin of the Korean Chemical Society
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• v.30 no.11
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• pp.2769-2772
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• 2009

• Journal of Life Science
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• v.19 no.5
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• pp.639-643
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• 2009

High temperature stress might affect the yield and quality of Chinese cabbage. In order to develop cultivars resistant to high temperature stress, we developed polymorphic DNA markers for trehalose synthesis genes related to abiotic stress resistance. A total of 28 Brassica rapa ESTs homologous to trehalose synthesis genes of Arabidopsis were found from the NCBI database. The polymorphic DNA sequences were searched between Chinese cabbages - Chiifu, which is relatively susceptible to high temperature stress, and Kenshin, which is tolerant to high temperature stress. Among the 28 ESTs, we found 10 ESTs that have either insertion/deletion and/or single nucleotide polymorphism between the two cultivars. Those polymorphic sites were then targeted for the development of 10 PCR based markers. These molecular markers related to trehalose genes could be used not only to test their relationship with abiotic stress resistance in Chinese cabbage, but also the development of abiotic stress resistant cultivars using MAS.

• BMB Reports
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• v.42 no.6
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• pp.373-379
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• 2009

5-Hydroxyuridine (5-OHU) is a major lesion of uridine and cytosine produced in RNA by various chemical oxidants. To elucidate its biochemical and biophysical effects on RNA replication, the site-specifically modified oligoribonucleotides containing 5-OHU were synthesized with C5-hydroxy-5'-ODMTr-2'-TBDMS-uridine phosphoramidite using automated solid phase synthesis. The base-pairing properties of nucleotides opposite 5-OHU in 24 mer oligoribonulcleotides with dNTP were studied using three reverse transcriptases (Super-$Script^{TM}II$-, AMV-, MMLV-RT) in cDNA synthesis. Adenine as well as guanine was incorporated preferentially by all reverse transcriptases. In the UV-melting temperature experiment, the results from the relative stabilities of the base pairs were A : 5-OHU > G : 5-OHU > T : 5-OHU $\approx$ C : 5-OHU. Circular Dichroism (CD) studies showed that DNA-RNA containing 5- OHU heteroduplexes exhibit a similar conformation between the A-type RNA and B-type DNA. These results suggest that 5- OHU from oxidative damage was mainly influenced by adenine mismatch.

• Journal of Environmental Health Sciences
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• v.24 no.2
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• pp.126-133
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• 1998

Effects of B(a)P on preimplantation mouse embryos in vitro were studied. Preimplantation mouse embryos were exposed to a concentration of 0.3, 1, 3 and 10 $\mu$M B(a)P for 72 hrs. The toxicological effects of B(a)P were evaluated by morphological observation of embryos up to the blastocyst stage, and by measuring DNA, RNA and protein synthesis by radioactive precursor incorporation. At 1 $\mu$M B(a)P did not affect preimplantation development but interfered with hatching and ICM formation. Suppressing effect of ICM formation was dose dependent. At the eight cell stage, the developmental rate was decreased at above 3 $\mu$M of B(a)P. At the blastocyst stage, attachment and trophoblast outgrowth were diminished at the 10 $\mu$M of B(a)P and ICM formation was decreased at 1 $\mu$M of B(a)P. Inner cell number of blastocyst was decreased dose dependently. So, number of ICM was one of the most sensitive and toxicological end point. The RNA incorporation rate of 0.1 $\mu ^3$H-uridine was dosedependent and the protein incroporation of 0.5 $\mu Ci ^{35}$S-methionine showed a significant decrease after 48 hrs. But the DNA incorporation rate of methyl-$^3$H thymidine was not affected. Our results suggested that B(a)P did not affect the DNA replication but transcription was inhibited by dose dependent manner. There delay of development during the blastocyst stage was mainly due to the inhibition of RNA synthesis followed by protein synthesis.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.3
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• pp.623-627
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• 2005

Abnormal thyroid cell proliferation has a very important role in hypothyroidism. Thyroid stimulating hormone (TSH) stimulates proliferation and maintains differentiated function in thyroid follicular cells. A functioning rat thyroid cell line (FRTL) was used to study the effect of Gamgung-tang (GGT, Glycyrrhizae Radix, black beans, Angelicae Radix and Cnidii Rhizoma) on proliferation and cAMP accumulation of thyrocytes. Proliferation of cell was assessed by DNA synthesis and incorporation of $[^3H]thymidine$ into DNA. The concentration of cAMP was measured simultaneously with growth assessment. Extract of GGT ($0.15{\sim}0.9\;mg/ml$ increased DNA synthesis in a dose-dependent manner. GGT at 0.6 (p<0.05) and 0.9 mg/ml (p<0.01) significantly increased $[^3H]thymidine$ incorporation. A comparable effect was observed with TSH. GGT also enhanced cAMP accumulation. These results indicate that GGT increases the proliferation of thyrocytes and may be considered a promising agent for the treatment of autoimmune thyroid disease.

• Korean Journal of Pharmacognosy
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• v.34 no.3 s.134
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• pp.237-241
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• 2003

This study was carried out to test the growth inhibitory effects of sesamolin obtained from sesame seeds. Sesamolin inhibited the growth of human leukemia HL-60 cells in cultures and the synthesis of macromolecules in dose- and time-dependent manners. Sesamolin in the $60{\sims}100\;{\mu}g/ml$ range was cytostatic. At concentrations greater than $200\;{\mu}g/ml$ sesamolin was cytocidal to HL-60 cells and at $60\;{\mu}g/ml$ inhibited the synthesis of DNA, RNA and protein in HL-60 cells by 35.1, 6.1, and 5.3%, whereas at $200\;{\mu}g/ml$ these inhibitions were 86.8%, 81.5% and 96.7%, respectively. The inhibitory effect of sesamolin on DNA synthesis was irreversible.