• Journal of Microbiology and Biotechnology
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• v.21 no.9
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• pp.979-987
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• 2011

Culture pH change has some important roles in signal transduction and secondary metabolism. We have already reported that acidic pH shock enhanced actinorhodin production in Streptomyces coelicolor. Among many potential governing factors on pH variation, the putative $Na^+/H^+$ antiporter (sha) genes in S. coelicolor have been investigated in this study to elucidate the association of the sha on pH variation and secondary metabolism. Through the transcriptional analysis and overexpression experiments on 8 sha genes, we observed that most of the sha expressions were promoted by pH shock, and in the opposite way the pH changes and actinorhodin production were enhanced by the overexpression of each sha. We also confirmed that sha8 especially has a main role in maintaining cell viability and pH homeostasis through $Na^+$ extrusion, in salt effect experiment under the alkaline medium condition by deleting sha8. Moreover, this gene was observed to have a function of pH recovery after pH variation such as the pH shock, being able to cause the sporulation. However, actinorhodin production was not induced by the only pH recovery. The sha8 gene could confer on the host cell the ability to recover pH to the neutral level after pH variation like a pH drop. Sporulation was closely associated with this pH recovery caused by the action of sha8, whereas actinorhodin production was not due to such pH variation patterns alone.

• Journal of Microbiology and Biotechnology
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• v.27 no.2
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• pp.262-270
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• 2017

Yersinia enterocolitica is a well-known foodborne pathogen causing gastrointestinal infections worldwide. The strain Y. enterocolitica FORC_002 was isolated from the gill of flatfish (plaice) and its genome was sequenced. The genomic DNA consists of 4,837,317 bp with a GC content of 47.1%, and is predicted to contain 4,221 open reading frames, 81 tRNA genes, and 26 rRNA genes. Interestingly, genomic analysis revealed pathogenesis and host immune evasion-associated genes encoding guanylate cyclase (Yst), invasin (Ail and Inv), outer membrane protein (Yops), autotransporter adhesin A (YadA), RTX-like toxins, and a type III secretion system. In particular, guanylate cyclase is a heat-stable enterotoxin causing Yersinia-associated diarrhea, and RTX-like toxins are responsible for attachment to integrin on the target cell for cytotoxic action. This genome can be used to identify virulence factors that can be applied for the development of novel biomarkers for the rapid detection of this pathogen in foods.

• Journal of Microbiology and Biotechnology
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• v.30 no.11
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• pp.1651-1658
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• 2020

Since Zika virus (ZIKV) was first detected in Uganda in 1947, serious outbreaks have occurred globally in Yap Island, French Polynesia and Brazil. Even though the number of infections and spread of ZIKV have risen sharply, the pathogenesis and replication mechanisms of ZIKV have not been well studied. ZIKV, a recently highlighted Flavivirus, is a mosquito-borne emerging virus causing microcephaly and the Guillain-Barre syndrome in fetuses and adults, respectively. ZIKV polyprotein consists of three structural proteins named C, prM and E and seven nonstructural proteins named NS1, NS2A, NS2B, NS3, NS4A, NS4B, and NS5 in an 11-kb single-stranded positive sense RNA genome. The function of individual ZIKV genes on the host innate immune response has barely been studied. In this study, we investigated the modulations of the NF-κB promoter activity induced by the MDA5/RIG-I signaling pathway. According to our results, two nonstructural proteins, NS2A and NS4A, dramatically suppressed the NF-κB promoter activity by inhibiting signaling factors involved in the MDA5/RIG-I signaling pathway. Interestingly, NS2A suppressed all components of MDA5/RIG-I signaling pathway, but NS4A inhibited most signaling molecules, except IKKε and IRF3-5D. In addition, both NS2A and NS4A downregulated MDA5-induced NF-κB promoter activity in a dosedependent manner. Taken together, our results suggest that NS2A and NS4A signifcantly antagonize MDA5/RIG-I-mediated NF-κB production, and these proteins seem to be controlled by different mechanisms. This study could help understand the mechanisms of how ZIKV controls innate immune responses and may also assist in the development of ZIKV-specific therapeutics.

• Journal of the Korean Chemical Society
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• v.38 no.7
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• pp.509-515
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• 1994

The interactions of 11 kinds of primary and secondary alkylammonium ions with cyclic (12C4, 15C5, 18C6, DT18C6 and DA18C6) and acyclic$(Q_2O_5)$ polyethers were investigated by NMR titration and conductometry. All of the alkylammonium ions under investigation form the relatively stable 1 : 1 complexes with crown ethers and acyclic polyether by H-bond. The interactions of alkylammonium ions with analogeous hosts having different size were in the order of 18C6 > 15C5 > 12C4, and the strengthes of donor atoms toward the alkylammonium ions were in the order of N > O > S. 18C6 forms more favorable interactions with primary alkylammonium ions than secondary alkylammonium ions, otherwise DA18C6 shows the opposite behaviors. The stability constants for complexations of 18C6 with the alkylammonium ions were determined conductometrically in methanol at 25$^{\circ}C$. The major factors affecting the stability of complexes were the type of alkylammonium ions, the length of alkyl-chain and the steric hindrance due to the structure of alkyl groups on complexation.

• Environmental Mutagens and Carcinogens
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• v.20 no.1
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• pp.26-33
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• 2000

Genetic polymorphisms of metabolizing enzymes to chemical carcinogens have been recognized as a major important host factors in human cancers. To datermine the frequencies of genotypes of CYP1A1 and GSTM1 metabolizing enzymes in healthy controls and head and neck cancer patients in Korean and to identify the relative high risk genotypes of these metabolizing enzymes to head and neck cancer, we have analyzed 133 head and neck cancer patients and corresponding healthy controls matched in age and sex using polymerase chain reaction-restriction fragment length polymorphism (PCR-RELP). In analysis of CYP1A1, the Val/Val genotype of exon 7 polymorphism and m2/m2 genotype of Msp 1 polymorphism were associated with higher relative risks to head and neck cancers (Odds ratio : 2.34, 95% CI : 0.79-6.96 and 1.27, 95% CI : 0.59-2.73, respectively). In combined genotyping of CYP1A1 and GSTMI enzymes polymorphisms, the patients with Val/Val ad GSTM1(-), and m1/m21 and GSTM1(-) combined genotypes had higher relative risks than the patients with each base genotype of combined genotypes (Odds ratio : 4.57, 95% CI : 0.5-41.25 and 1.65, 95% CI L 0.73-3.77, respectively). These results sugget the combined genotyping of metabolizing enzymes could be useful for predicting individual genetic susceptibility and screening the high risk subpopulation to head and neck cancer in Korea.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.40 no.6
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• pp.260-265
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• 2014

Objectives: The aim of this study was to verify the clinical effectiveness of decompression in decreasing the size of a cyst. In addition to the different types of cysts, we tried to reveal what effect host factors, such as the initial size of the lesion and the age of the patient, have on the velocity of cyst shrinkage. Materials and Methods: With the aid of a panoramic view, we measured the size of the cysts before and after decompression in 13 dentigerous cysts (DCs), 14 keratocystic odontogenic tumors (KTOCs), and 5 unicystic ameloblastoma (UA) cases. The velocity of shrinkage in the three cystic groups was calculated. Relationships between the age of the patient, the initial size of the cyst, and the shrinkage velocity were investigated. Results: The three types of cysts showed no inter-type differences in their velocity of shrinkage. However, there was a statistically meaningful relationship between the initial size of the lesion and the absolute velocity of shrinkage in the DC group (P=0.02, R=0.65) and the KTOC group (P=0.02, R=0.56). There was also a significant relationship between the age of the patient and the absolute velocity of shrinkage in the KTOC group (P=0.04, R=0.45) and the UA group (P=0.04, R=0.46). Conclusion: There was no difference in the decrease in size due to decompression among the different types of cysts. However, the age of the patient and the initial size of the lesion showed a significant relationship with the velocity of shrinkage.

• Journal of Information Processing Systems
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• v.8 no.2
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• pp.347-358
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• 2012

Recently, security researches have been processed on the method to cover a broader range of hacking attacks at the low level in the perspective of hardware. This system security applies not only to individuals' computer systems but also to cloud environments. "Cloud" concerns operations on the web. Therefore it is exposed to a lot of risks and the security of its spaces where data is stored is vulnerable. Accordingly, in order to reduce threat factors to security, the TCG proposed a highly reliable platform based on a semiconductor-chip, the TPM. However, there have been no technologies up to date that enables a real-time visual monitoring of the security status of a PC that is operated based on the TPM. And the TPB has provided the function in a visual method to monitor system status and resources only for the system behavior of a single host. Therefore, this paper will propose a m-TMS (Mobile Trusted Monitoring System) that monitors the trusted state of a computing environment in which a TPM chip-based TPB is mounted and the current status of its system resources in a mobile device environment resulting from the development of network service technology. The m-TMS is provided to users so that system resources of CPU, RAM, and process, which are the monitoring objects in a computer system, may be monitored. Moreover, converting and detouring single entities like a PC or target addresses, which are attack pattern methods that pose a threat to the computer system security, are combined. The branch instruction trace function is monitored using a BiT Profiling tool through which processes attacked or those suspected of being attacked may be traced, thereby enabling users to actively respond.

• The Journal of Natural Sciences
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• v.14 no.1
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• pp.51-61
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• 2004

T7 RNA polymerase is a single subunit RNA polymerase able to accomplish whole transcription process without auxiliary factors. T7 phage lysozyme involcing in destruction of host cell wall repress T7 transcription and affects transcription termination process. Therefore expression vector pT7lys containing T7 phage lysozyme gene was constructed and expressed. T7 phage lysozyme protein was purified to homogeneity by Ni-NTA column chromatography. Also amidase activity of the purified lysozyme was identified. In order to understand the effect of the lysozyme on the sequence specific transcription termination. T7 transcription elongation complexes at the site rrnB T1 transcription termination signal were made in the presence the lysozyme. The results shows that the transcription elongation complexes are unstable in the presence of T7 phage lysozyme.

• Journal of Microbiology
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• v.42 no.2
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• pp.111-116
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• 2004

It is known that Bacillus subtilis glutamyl-tRNA synthetase (GluRS) mischarges E. coli $tRNA_{1}$$^{Gln}$ with glutamate in vitro. It has also been established that the expression of B. subtilis GluRS in Escherichia coli results in the death of the host cell. To ascertain whether E. coli growth inhibition caused by B. subtilis GluRS synthesis is a consequence of Glu-$tRNA_{1}$$^{Gln}$ formation, we constructed an in vivo test system, in which B. subtilis GluRS gene expression is controlled by IPTG. Such a system permits the investigation of factors affecting E. coli growth. Expression of E. coli glutaminyl-tRNA synthetase (GlnRS) also amelio-rated growth inhibition, presumably by competitively preventing $tRNA_{1}$$^{Gln}$ misacylation. However, when amounts of up to 10 mM L-glutamine, the cognate amino acid for acylation of $tRNA_{1}$$^{Gln}$, were added to the growth medium, cell growth was unaffected. Overexpression of the B. subtilis gatCAB gene encoding Glu-$tRNA^{Gln}$ amidotransferase (Glu-AdT) rescued cells from toxic effects caused by the formation of the mis-charging GluRS. This result indicates that B. subtilis Glu-AdT recognizes the mischarged E. coli Glu-$tRNA_{1}$$^{Gln}$, and converts it to the cognate Gln-$tRNA_{1}$$^{Gln}$ species. B. subtilis GluRS-dependent Glu-$tRNA_{1}$$^{Gln}$ formation may cause growth inhibition in the transformed E. coli strain, possibly due to abnormal protein synthesis.

• The Journal of the Korean dental association
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• v.52 no.4
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• pp.218-233
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• 2014

Bispbosphonates are a class of pharmaceutic agents, which induce apoptosis of osteoclast as well as impair osteoclastic activity to suppress bone resorption. Thus, bisphophonates are effectively used to treat osteoporosis, multiple myeloma and to prevent bone metastases of malignant cancer. However, recently dental disease have been reported associated with Bisphosphonates. Thus, there are a number of discussions about proper prevention and treatment of bisphosphonate-related osteonecrosis of jaw(BRONJ). Marshall R. Urist in 1965 made the seminal discovery that a specific protein, BMP(bone morphogenetic protein), found in the extracellular matrix of demineralized bone could induce bone formation newly when implanted in extraosseous tissues in a host. BMPs are multi-functional growth factors which are members of the transforming growth factor-beta super family and their ability is that plays a pivotal roll in inducing bone. About 18 BMP family members have been identified and characterized. Among of them, BMP-2 and BMP-7 have significant importance in bone development. In this study, patients of BRONJ were recieved who visited Department of oral and maxillofacial surgery, school of dentistry, Wonkwang university for past 3 years from 2011 to 2013. We focused on the results of the surgical intervention. We suggest that new strategy of treatment used to rhBMP-2 and LFA(Lidocaine-Fibrinogen-Aprotinin)-collagen scaffold for patients of BRONJ. The purpose of this paper is to give a brief overview of BMPs and to critically review the clinical data currently available on rhBMP-2 and LFA collage scaffold.