• The Microorganisms and Industry
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• v.12 no.1
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• pp.28-34
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• 1986

Nucleic acids do not only carry the genetic information, but are also the only substances being able of self-replication. Molecular cloning, an essential tool in biotechnology, requires among other things, an understanding of the mechanisms of replication which at present is fairly well known. After an introduction to the general principle, the status of art on replication procedure and its implication for biotechnology are dealt with.

• Preventive Nutrition and Food Science
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• v.21 no.4
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• pp.317-322
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• 2016

Mitochondrial biogenesis is a complex process requiring coordinated expression of nuclear and mitochondrial genomes. The peroxisome proliferator-activated receptor gamma co-activator 1-alpha (PGC-$1{\alpha}$) is a key regulator of mitochondrial biogenesis, and it controls mitochondrial DNA (mtDNA) replication within diverse tissues, including muscle tissue. The aim of this study was to investigate the effects of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on mtDNA copy number and PGC-$1{\alpha}$ promoter activity in $C_2C_{12}$ muscle cells. mtDNA copy number and mRNA levels of genes related to mitochondrial biogenesis such as PGC-$1{\alpha}$, nuclear respiratory factor 1 (NRF1) and mitochondrial transcription factor A (Tfam) were assayed by quantitative real-time PCR. The PGC-$1{\alpha}$ promoter from -970 to +412 bp was subcloned into the pGL3-basic vector, which includes a luciferase reporter gene. Both EPA and DHA significantly increased mtDNA copy number, dose and time dependently, and up-regulated mRNA levels of PGC-$1{\alpha}$, NRF1, and Tfam. Furthermore, EPA and DHA stimulated PGC-$1{\alpha}$ promoter activity in a dose-dependent manner. These results suggest that EPA and DHA may modulate mitochondrial biogenesis, which was partially associated with increased mtDNA replication and PGC-$1{\alpha}$ gene expression in $C_2C_{12}$ muscle cells.

• Molecules and Cells
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• v.40 no.2
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• pp.143-150
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• 2017

Homologous recombination (HR) is necessary for maintenance of genomic integrity and prevention of various mutations in tumor suppressor genes and proto-oncogenes. Rad51 and Rad54 are key HR factors that cope with replication stress and DNA breaks in eukaryotes. Rad51 binds to single-stranded DNA (ssDNA) to form the presynaptic filament that promotes a homology search and DNA strand exchange, and Rad54 stimulates the strand-pairing function of Rad51. Here, we studied the molecular dynamics of Rad51 and Rad54 during the cell cycle of HeLa cells. These cells constitutively express Rad51 and Rad54 throughout the entire cell cycle, and the formation of foci immediately increased in response to various types of DNA damage and replication stress, except for caffeine, which suppressed the Rad51-dependent HR pathway. Depletion of Rad51 caused severe defects in response to postreplicative stress. Accordingly, HeLa cells were arrested at the G2-M transition although a small amount of Rad51 was steadily maintained in HeLa cells. Our results suggest that cell cycle progression and proliferation of HeLa cells can be tightly controlled by the abundance of HR proteins, which are essential for the rapid response to postreplicative stress and DNA damage stress.

• Journal of environmental and Sanitary engineering
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• v.13 no.3
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• pp.37-42
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• 1998

2-Bromopropane has been implicated to be the reason for the mass intoxication of workers at an electronic company in Korea. 2-Bromopropane deposition and pattern of DNA replication in mouse fetuses were analyzed after intravenous injection of 2-bromopropane. Injections were administered to pregnant ICR mice in order to cytogenetically evaluate transplacental 2-bromopropane. The results are summarized as follows; 1. A dose-dependent effect on DNA replication was observed equally in the lung, liver and kideneys of fetuses has been exposed to 2-bromopropane transplacentally as reductions of the labeling index. 2. Deposition of transplacentally administred 2-bromopropane in the fetus was lower than placenta.

• BMB Reports
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• v.28 no.4
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• pp.336-341
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• 1995

Using a mutant M13 phage derivative lacking a great part of the complementary strand synthesis origin, we identified six single-strand initiation (ssi) signals for DNA replication in pACYC184, pLG214, pGKV21, and pDPT270 plasmids, and named them $ssiA_{YC}$, $ssiA_{LG}$, $ssiB_{LG}$, $ssiA_{KV}$, $ssiA_{PT}$, and $ssiB_{PT}$, respectively. Two of them were from pDPT270, one from downstream the on of pACYC184, two from pLG214, one from upstream the plus origin of pGKV21. Introduction of these ssi signals into the deleted $ori_c$ site of a mutant filamentous M13 phage ($M13{\Delta}lac182$) resulted in the restoration of growth activity of this phage. These ssi signals were classified into a number of groups on the basis of sequence similarity. $ssiA_{YC}$ and $ssiA_{LG}$ show extensive sequence homology to the n'-site (primosome assembly sites) of ColE1, whereas $ssiB_{PT}$ is homologous to the n'-site of ${\Phi}X174$. $ssiA_{PT}$ belongs to G4-type ssi signals which require only dnaG primase and SSB protein for the priming of replication. In addition, possible biological roles of these ssi signals are discussed.

• Korean Journal of Microbiology
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• v.32 no.3
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• pp.186-191
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• 1994

The origin of the leading strand replication (ori) and of lagging strand replication (M-O) of R-plasmid pSBK203 was identified and its base sequence was determined. About 50 bp of ori sequence residues overlapped with the structural gene of rep. Sequence comparison reveals that pSBK-ori shares obvious identities with those of pT181 family and consists of two regions, one is conserved and the other is variable region. Of two palindrome sequence located one after another in upstream region of rep gene, palA' instead of palA which shares sequence homology with diverse family of plasmids such as pOX6, pC194, and pE194 seems to act as a signal for conversion of primarily replicated ssDNA to dsDNA (minus origin (M-O)).

• Archives of Pharmacal Research
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• v.27 no.1
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• pp.77-82
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• 2004

DA-125, a novel derivative of adriamycin, is known for its anti-cancer activity. In this study, the inhibitory mechanism of DA-125 on topoisomerase was investigated in the simian virus 40 (SV40) replicating CV-1 cell by studying the SV40 DNA replication intermediates and DNA-topoisomerase complexes. DNA-protein complexes that were formed in the drug-treated cells were quantitated by using a glass filter assay. SV40 DNA replication intermediates that were accumulated in the drug-treated CV-1 cell were analyzed in a high resolution gel. DA-125 did not accumulate B-dimers of SV40 DNA replication intermediates which were found in the adriamycin-treated CV-1 cells. DA-125 induced a dose-dependent formation of the DNA-protein complexes, while adriamycin did not. When adriamycin and etoposide (VP16) were added to the SV40-infected cells at the same time, adriamycin blocked the formation of the DNA-protein complexes induced by VP16 in a dose-dependent manner. However, DA-125 blocked the formation of the DNA-protein complexes induced by VP16 up to the maximum level of the DNA-protein complexes that were induced by DA-125 alone. Adriamycin and DA-125 did not inhibit the formation of the DNA-protein complexes that were caused by camptothecin, a known topoisomerase I poison. DA-125 is bifunctional in inhibiting topoisomerase II because it simultaneously has the properties of the topoisomerase II poison and the DNA intercalator. As a topoisomerase II poison, DA-125 alone induced dose-dependent formation of the DNA-protein complexes. However, as a DNA intercalator, it quantitatively inhibited the formation of the DNA-protein complexes induced by a strong topoisomerase II poison VP16. Furthermore considering that the levels of the DNA-protein complex induced by VP16 were decreased by DA-125 in terms of the topoisomerase II poison, we suggest that DA-125 has a higher affinity to the drug-binding sites of DNA than VP16 has.

• BMB Reports
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• v.43 no.11
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• pp.744-749
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• 2010

The aim of this work was to determine whether intrinsically bent DNA sites are present at, or close to, the mammalian replication origins oriGNAI3 and oriB in the Chinese hamster AMPD2 locus. Using an electrophoretic mobility shift assay and in silico analysis, we located four intrinsically bent DNA sites (b1 to b4) in a fragment that contains the oriGNAI3 and one site (b5) proximal to oriB. The helical parameters show that each bent DNA site is curved in a left-handed superhelical writhe. A 2D projection of 3D fragment trajectories revealed that oriGNAI3 is located in a relatively straight segment flanked by bent sites b1 and b2, which map in previously identified Scaffold/Matrix Attachment Region. Sites b3 and b4 are located approximately 2 kb downstream and force the fragment into a strong closed loop structure. The b5 site is also located in an S/MAR that is found just downstream of oriB.

• Korean Journal of Microbiology
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• v.36 no.2
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• pp.103-108
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• 2000

We have cloned and analyzed cDNA coding for non-virion (NV) protein of the m V - P R T The NV gene contained 336 bp open readmg frame and encoded a protein of 11 1 amino acids with a molecular weight of 13.2 kDa. The deduced amino acid sequence of NV of IHNVPRT was found to be 90-95% identical to those of foreign isolates of IHNV. These results indicate that NV gene of the MNV is highly conserved among &ifferent strains of THNV Northern blot analyses revealed that the levels of NV gene expression were strongly elevated after 20 h post-infection. In order to identify the role of NV in the replication of MNV in fish cells, IHNVinfected cells were treated with antisense oligonucleotides. While IHNV-PRT exposed to glycoprotein (G) antisense oligonucleotide showed severely reduced growth, the growth of virus exposed to NV antisense oligonucleotide was not affected by NV antisense oligonucleotide, which suggests that NV is not essential for replication of IHNV in fish cells.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.315.1-315.1
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• 2002

DNA topoisomerases I (topo I) and II are essential enzymes that relax DNA supercoiling and relieve torsional strain during DNA processing. including replication. transcription. and repair. Topo I relaxes DNA by cleaving one strand of DNA by attacking a backbone phosphale with a catalytic lyrosine (Tyr723. human topo I). This enzyme has recently been investigated as a new target for antineoplastic drugs. Inhibitors to the enzyme intercalate between the DNA base pairs. interfering religation of cleaved DNA, therefore inhibit the activity of topo I. (omitted)