• Biomolecules & Therapeutics
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• v.19 no.3
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• pp.282-287
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• 2011

Sirt1, a nicotinamide adenine dinucleotide ($NAD^+$)-dependent histone deacetylase, is known to deacetylate a number of proteins that are involved in various cellular pathways such as the stress response, apoptosis and cell growth. Modulation of the stress response by Sirtuin 1 (Sirt1) is achieved by the deacetylation of key proteins in a cellular pathway, and leads to a delay in the onset of cancer or aging. In particular, Sirt1 is known to play an important role in maintaining genomic stability, which may be strongly associated with a protective effect during tumorigenesis and during the onset of aging. In these studies, Sirt1 was generated in stably expressing cells and during the stimulation of DNA damage to examine whether it promotes survival. Sirt1 expressing cells facilitated the repair of DNA damage induced by either ionizing radiation (IR) or bleomycin (BLM) treatment. Fastened damaged DNA repair in Sirt1 expressing cells corresponded to prompt activation of Chk2 and ${\gamma}$-H2AX foci formation and promoted survival. Inhibition of Sirt1 enzymatic activity by a chemical inhibitor, nicotinamide (NIC), delayed DNA damage repair, indicating that promoted DNA damage repair by Sirt1 functions to induce survival when DNA damage occurs.

• Journal of Microbiology and Biotechnology
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• v.15 no.4
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• pp.722-727
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• 2005

Cytosolic sialidase (Neu2), a member of the sialidase family that is responsible for hydrolysis of sialic acid from the terminal position of sialoglycoconjugates, is poorly expressed in skeletal muscle and not detected in any other adult tissues. Thus, we isolated Neu2 cDNA using splicing by overlap extension (SOEing). In order to further characterize this enzyme, a His-tagged derivative was expressed in the bacterial expression system and purified by $Ni^{2+}$-affinity chromatography. A recombinant product of approximately 42 kDa had sialidase activity toward 4-methyl-umbelliferyl-$\alpha$-D-N-acetylneuraminic acid (4MU-NeuAc). The optimal pH and temperature of the recombinant Neu2 for 4MU-NeuAc was 6.0 and $37.5^{\circ}C$, respectively. The metal ions, such as $Cu^{2+}\;and\;Cd^{2+}$, showed strong inhibitory effect on the activity of the enzyme. The enzyme efficiently hydrolyzed the gangliosides GM3 and GD3 and had relatively low activities on ganglioside GD1a and GD1b, $\alpha$2-3 sialyllactose, and sialylated glycoproteins such as fetuin, transferrin, and orsomucoid, but had hardly any activities on $\alpha$2-6 sialyllactose and ganglioside GM1 and GM2. We concluded that the recombinant Neu2 has a sialidase activity toward glycoproteins as well as gangliosides.

• Journal of Microbiology and Biotechnology
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• v.9 no.2
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• pp.213-218
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• 1999

Fructans are polyfructose molecules that function as nonstructural storage carbohydrates in several plants. In addition, it has been suggested that, due to their solubility, they can play an important role in helping plants survive periods of osmotic stress. In order to study the effect of levan synthesis on plant growth, the coding region of the levansucrase gene, which was isolated from Zymomonas mobilis, was introduced into tobacco plants using Agrobacterium tumefaciens-mediated transformation. The presence of the levansucrase gene in transgenic plants was verified by genomic DNA gel blot analysis. RNA gel blot and immunoblot analyses showed an accumulation of the corresponding transcript and protein product of the bacterial levansucrase gene in transgenic plants. Furthermore, a thin layer chromatography analysis revealed that fructans were synthesized and deposited in transgenic tobacco plants. When $T_1$ seeds were germinated and grown under polyethylene glycol-mediated drought stress or cold stress, the transgenic seedlings displayed a substantially higher level of growth than that of untransformed plants. These results suggest that fructans may playa significant role in the tolerance of plants under osmotic stress.

• Journal of Microbiology and Biotechnology
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• v.20 no.9
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• pp.1322-1330
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• 2010

Three types of nuruk were made from rice, wheat, and a rice-glasswort (6:4) mixture. Nuruk, makgeolli, and vinegar were manufactured with rice nuruk (RN), wheat nuruk (WN), and rice-glasswort nuruk (RGN). The variable region of 18S or 16S rDNA amplified with genomic DNA extracted directly from nuruk-, makgeolli-, and vinegar-making cultures was analyzed via temperature gradient gel electrophoresis (TGGE). The sequence of the 18S rDNA variable region extracted from the TGGE gel for nuruk was 99% homologous with Aspergillus sp. and that for the makgeolli-making culture was 99% homologous with Saccharomyces sp. and Saccharomycodes sp. The sequence of the 16S rDNA variable region extracted from TGGE gel for the vinegar-making culture was 98% homologous, primarily with the Acetobacter sp. The eukaryotic and prokaryotic diversities in the nuruk-, makgeolli-, and vinegar-making cultures was not significantly altered by the addition of glasswort. Prokaryotic diversity was higher than eukaryotic diversity in the nuruk, but eukaryotic diversity was higher than prokaryotic diversity in the makgeolli-making culture, on the basis of the TGGE patterns. No 18S rDNA was amplified from the DNA extracted from the vinegar-making culture. The diversity of the microbial community in the process from nuruk to vinegar was slightly affected by the type of raw material utilized for nuruk-making. The saccharifying activity and ethanol productivity of nuruk, polyphenol content in makgeolli, and acetic acid and polyphenol content in the vinegar were increased as a result of the addition of glasswort. In conclusion, the glasswort may be not simply an activator for the growth of microorganisms during the fermentation of nuruk, makgeolli, or vinegar, but also a nutritional supplement that improves the quality of vinegar.

• Korean Journal of Veterinary Research
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• v.38 no.2
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• pp.304-313
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• 1998

Sixteen Korean field transmissible gastroenteritis viruses (TGEVs) were isolated using swine testicular cell (STC) and the genomic diversity of them was analyzed. All TGEV isolates produced a typical cytopathic effect in STC and were confirmed as TGEV by immunofluorescence assay using monoclonal antibody against TGEV and PCR using TGEV specific primers. RNAs from TGEV field isolates and vaccine TGEV were extracted and amplified by RT and PCR. The RT-PCR products were digested with selected restriction enzymes and analyzed RFLP patterns. The N-terminal end region of S gene and ORF 3 and 3-1 genes of TGEV amplified by TGEV specific primer pairs seemed to be conserved. Most specific variations were detected in S gene amplified by TGEV 4/6 primer pairs which includes antigenic sites A and D. When the PCR products were treated with Sau3AI and Ssp I, Bvac(vaccine strain), field isolates 133 and 347 were differentiated from Miller and Purdue types. In the case of D5 field isolates, it was classified into Purdue type by Sau 3AI but classified into independent TGEV by Ssp I. Two different TGEV strains from D2 sample were confirmed by plaque purification and RT-PCR-RFLP analysis. To investigate the change occurring in TGEV genome after serial passage, the TGEV P44 strain was passaged through STC. There were specific changes in S gene and a large deletion was observed in ORF 3 and 3-1 genes. These studies showed that a distinct difference in genome exists among TGEV field isolates.

• Molecular & Cellular Toxicology
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• v.2 no.2
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• pp.120-125
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• 2006

Phenytoin is an anti-epileptic. It works by slowing down impulses in the brain that cause seizures. The recent microarray technology enables us to understand possible mechanisms of genes related to compounds which have toxicity in biological system. We have studied that the effect of a compound related to hepatotoxin in vitro system using a rat whole genome microarray. In this study, we have used a rat liver epithelial cell line WB-F344 and phenytoin as a hepatotoxin. WB-F344 was treated with phenytoin for 1 to 24 hours. Total RNA was isolated at times 1, 6 and 24h following treatment of phenytoin, and hybridized to the microarray containing about 22,000 rat genes. After analysis with clustering methods, we have identified a total of 1,455 differentially expressed genes during the time course. Interestingly, about 1,049 genes exhibited differential expression pattern in response to phenytoin in early time. Therefore, the identification of genes associated with phenytoin in early response may give important insights into various toxicogenomic studies in vitro system.

• Molecular & Cellular Toxicology
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• v.2 no.2
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• pp.75-80
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• 2006

Biomarkers identify various stages and interactions on the pathway from exposure to disease. The three categories of biomarkers are those measuring susceptibility, exposure and effect. Susceptibility biomarkers are identifiable genetic variations affecting absorption, metabolism or response to environmental agents. Biomarkers of exposure indicate the amount of a foreign compound that is absorbed into the body. Biological measurements performed on human tissues are vastly expanding the capabilities of classical epidemiology, which has relied primarily on estimates of human exposure derived form chemical levels in the air, water, and other exposure routes. Biomarkers of exposure indicate the amount of a foreign compound that is absorbed into the body. Biological measurements performed on human tissues are vastly expanding the capabilities of classical epidemiology, which has relied primarily on estimates of human exposure derived form chemical levels in the air, water, and other exposure routes. The biomarker response is typical of chemical pollution by specific classes of compound, such as (i) heavy metals (mercury, cadmium, lead, zinc), responsible for the induction of metallothionein synthesis, and (ii) organochlorinated pollutants (PCBs, dioxins, DDT congeners) and polycyclic aromatic hydrocarbons (PAHs), which induce the mixed function oxygenase (MFO) involved in their bio transformations and elimination. Currently genomic researches are developed in human cDNA clone subarrays oriented toward the expression of genes involved in responses to xenobiotic metabolizing enzymes, cell cycle components, oncogenes, tumor suppressor genes, DNA repair genes, estrogen-responsive genes, oxidative stress genes, and genes known to be involved in apoptotic cell death. Several research laboratories in Korea for kicking off these Environmental Genomics were summarized.

• Journal of fish pathology
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• v.30 no.2
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• pp.71-78
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• 2017

The glycoprotein of novirhabdoviruses is known to play a critical role in the determination of host specificity. Viral hemorrhagic septicemia viruses (VHSVs) in different genotypes have different glycoprotein sequences and show different preferences for specific cell lines. In this study, to know whether the glycoprotein is solely responsible for the host cell preference of VHSV, a recombinant VHSV expressing vesicular stomatitis virus (VSV) glycoprotein instead of VHSV IVa glycoprotein (rVHSV-VSV-G) was generated by reverse genetics and inoculated into several fish cell lines, then, cytopathic effect (CPE) and viral growth caused by rVHSV-VSV-G infection were compared with those caused by rVHSV-wild that was previously generated and has the same genomic sequence with wild-type VHSV except a few nucleotides. The plaque numbers of rVHSV-VSV-G were significantly higher in EPC, BF-2 and GF cells than those of rVHSV-wild. However, in HINAE cells (originated from olive flounder), rVHSV-VSV-G titer was significantly lower than rVHSV-wild titer, and both recombinant VHSVs were not grown well in CHSE-214 cells. Although statistical significances were detected in the titers between rVHSV-wild and rVHSV-VSV-G in several cell lines, the cell line-preference order of rVHSV-VSV-G was not different from that of rVHSV-wild. These results suggest that the replacement of VHSV glycoprotein may not completely change host cell preference, and other regions of VHSV might also involve in the determination of host cell preference.

• Food Science of Animal Resources
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• v.31 no.4
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• pp.537-542
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• 2011

Biological or physiological genes that regulate metabolism and energy partitioning have the potential to influence economically important traits such as carcass and meat quality traits in beef cattle. The neuropeptide Y (NPY) functions as a central appetite stimulator and plays a major role in feed intake and energy-balance control. Therefore, the NPY gene is an excellent biological and physiological candidate gene for body weight, feeding, fatness or growth related traits in beef cattle. The objective of this study was to identify single nucleotide polymorphisms (SNPs) in the NPY gene and to evaluate the association of NPY SNP markers with carcass and meat quality traits in Korean cattle. The genomic region (711 bp) including intron 2 of NPY gene was amplified and sequenced, and five SNPs, g.4389 Del(C), g.4371Del(C), g.4271T>C, g.1899A>G and g.1517A>C, were identified. The PCR-RFLP method was then developed to genotype the individuals examined. The g.4271T>C SNP was significantly associated with M. Longissimus dori area (LDA) value (p<0.027). Animals with the TT ($78.144{\pm}0.950\;cm^2$) genotype had higher LDA than those with the CC ($72.266{\pm}2.039\;cm^2$), and animals with TC genotype showed intermediate value. This SNP genotype also showed a highly significant additive genetic effect for the LDA (p<0.01). No significant associations, however, was detected between any of the SNP genotype and other carcass traits measured in this study. In conclusion, SNP genotype of the NPY gene may be used as DNA markers to select animals that have a higher meat yield.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.17
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• pp.7929-7933
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• 2015

Background: The incidence of breast cancer in India is on the rise and is rapidly becoming the number one cancer in females, pushing the cervical cancer to the second position. Most of the predisposition to hereditary breast and ovarian cancer has been attributed to inherited defects in two tumor suppressor genes BRCA1 and BRCA2. Alterations in these genes have been reported in different populations, some of which are population-specific mutations showing founder effects. Two specific mutations in the BRCA1 (185delAG) and BRCA2 (6174delT) genes have been reported to be of high prevalence in different populations. The aim of this study was to estimate the carrier frequency of 185delAG and 6174delT mutations in eastern Indian breast cancer patients. Materials and Methods: We selected 231 histologically confirmed breast cancer patients from our tertiary cancer care center in eastern India. Family history was obtained by interview or a self-reported questionnaire. The presence of the mutation was investigated by allele specific duplex/multiplex-PCR on genomic DNA extracted from peripheral blood. Results: A total of 231 patients (age range: 26-77 years), 130 with a family history and 101 without were screened. The two founder mutations 185delAG in BRCA1 and 6174delT in BRCA2 were not found in any of the subjects. This was confirmed by molecular analysis. Conclusions: Our findings suggest that these BRCA mutations may not have a strong recurrent effect on breast cancer among the eastern Indian population. The contribution of these founder mutations to breast cancer incidence is probably low and could be limited to specific subgroups. This may be particularly useful in establishing further pre-screening strategies.