• Journal of Microbiology and Biotechnology
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• v.23 no.11
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• pp.1500-1508
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• 2013

Ebosin, a novel exopolysaccharide produced by Streptomyces sp. 139, has obvious antirheumatic arthritis activity in vivo, and its biosynthesis gene cluster (ste), consisting of 27 open reading frames, has been identified. This paper reports our study of the gene functionality of ste8, the predicted protein product of which is homologous to some bacterial chain length determinant Wzz proteins. For characterization of Ste8, ste8 was cloned and expressed in the mutant strain E. coli 086:H2 (${\Delta}wzz$). The functional complementation of wzz by ste8 was demonstrated by the restoration of wild-type lipopolysaccharide biosynthesis and increased levels of serum resistance of E. coli 086:H2 (${\Delta}wzz$) (pET30a-ste8). To examine the function of ste8 in ebosin biosynthesis, the gene was knocked out with a double crossover via homologous recombination. The molecular weight of the ebosin derivative EPS-8m produced by the mutant Streptomyces sp. 139 ($ste8^-$) was much lower than that of ebosin, and the binding activity of EPS-8m for IL-1R decreased significantly compared with ebosin. These results demonstrate that ste8 encodes a chain length determinant (Wzz) that functions in ebosin biosynthesis.

• Korean Journal of Microbiology
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• v.52 no.4
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• pp.487-494
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• 2016

In Saccharomyces cerevisiae, Paf1 complex consists of five proteins, and they are structurally and functionally well conserved in yeast, fruit fly, plants, and human. With binding to RNA polymerase II from transcription start site to termination site, Paf1 complex functions as a platform for recruiting many types of transcription factors to RNA polymerase II. Paf1 complex contributes to H2B ubiquitination and indirectly influences on H3K4 di- and tri-methylation by histone crosstalk. But the individual effects of five components in Paf1 complex on these two histone modifications including H2B ubiquitination and H3K4 methylation largely remained to be identified. In this study, we constructed the single-gene knockout mutants of each Paf1 complex component and observed H3K4 mono-, di-, and trimethylation as well as H2B ubiquitination in these mutants. Interestingly, in each ${\Delta}paf1$, ${\Delta}rtf1$, and ${\Delta}ctr9$ strain, we observed the dramatic defect in H3K4 monomethylation, which is independent of H2B ubiquitination, as well as H3K4 di- and trimethylation. However, the protein level of Set1, which is methyltransferase for H3K4, was not changed in these mutants. This suggests that Paf1 complex may directly influence on H3K4 methylation by directly regulating the activity of Set1 or the stability of Set1 complex in an H2B ubiquitination independent manner.

• Journal of Periodontal and Implant Science
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• v.34 no.1
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• pp.205-221
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• 2004

Periodontal ligament(PDL) cells have been known as playing an important roles in periodontal regeneration and gingival fibroblasts are also important to periodontal regeneration by forming connective tissue attachment. There were rare studies about the gene expression patterns of PDL cells and gingival fibroblasts, therefore in this study, we tried cDNA microarray-based gene expression monitoring to explain the functional differences of PDL cells and gingival fibroblasts in vivo and to confirm the characteristics of PDL cells. Total RNA were extracted from PDL cells and gingival fibroblasts of same person and same passages, and mRNA were isolated from the total RNA using Oligotex mRNA midi kit(Qiagen) and then fluorescent cDNA probe were prepared. And microarray hybridization were performed. The gene expression patterns of PDL cells and gingival fibroblasts were quite different. About 400 genes were expressed more highly in the PDL cells than gingival fibroblasts and about 300 genes were more highly expressed in the gingival fibroblasts than PDL cells. Compared growth factor- and growth factor receptor-related gene expression patterns of PDL cells with gingival fibroblasts, IGF-2, IGF-2 associated protein, nerve growth factor, placental bone morphogenic protein, neuron-specific growth- associated protein, FGF receptor, EGF receptor-related gene and PDGF receptor were more highly expressed in the PDL cells than gingival fibroblasts. The results of collagen gene expression patterns showed that collagen type I, type III, type VI and type VII were more highly expressed in the PDL cells than gingival fibroblasts, and in the gingival fibroblasts collagen type V, XII were more highly expressed than PDL cells. The results of osteoblast-related gene expression patterns showed that osteoblast specific cysteine-rich protein were more highly expressed in the PDL cells than gingival fibroblasts. The results of cytoskeletal proteins gene expression patterns showed that a-smooth muscle actin, actin binding protein, smooth muscle myosin heavy chain homolog and myosin light chain were more highly expressed in the PDL cells than gingival fibrobalsts, and ${\beta}-actin$, actin-capping protein(${\beta}$ subunit), actin- related protein Arp3(ARP) and myosin class I(myh-1c) were more highly expressed in the gingival fibroblasts than PDL cells. Osteoprotegerin/osteoclastogenesis inhibitory factor(OPG/OCIF) was more highly expressed in the PDL cells than gingival fibroblasts. According to the results of this study, PDL cells and gingival fibroblasts were quite different gene expression patterns though they are the fibroblast which have similar shape. Therefore PDL cells & gingival fibroblasts are heterogeneous populations which represent distinct characteristics. If more studies about genes that were differently expressed in each PDL cells & gingival fibroblasts would be performed in the future, it would be expected that the characteristics of PDL cells would be more clear.

• Journal of Periodontal and Implant Science
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• v.46 no.5
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• pp.320-328
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• 2016

Purpose: Human saliva, as a vital part of the immune defense system, contains a number of distinct proteins and peptides. Recently human common salivary protein 1 (CSP1) has been identified as an abundant salivary protein and may play a role in promoting the binding of cariogenic bacteria to salivary pellicles. However, nothing else is known regarding the role of CSP1 in periodontology. The aim of this study was to quantify and compare CSP1 levels between healthy subjects and periodontal patients. Methods: This controlled clinical study was conducted in periodontally healthy individuals and patients with chronic periodontitis Chonbuk National University Hospital, with Institutional Review Board approval. Whole saliva samples were collected from 36 healthy subjects and 33 chronic periodontitis patients and analyzed. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immune blotting were conducted to ensure that anti-CSP1 monoclonal antibody (mAb) binds to CSP1 in human saliva. A sandwich enzyme-linked immunosorbent assay (ELISA) system was house-fabricated using mAb-hCSP1#14 and mAb-hCSP1#4 as a capture and a detector mAb, respectively. The CSP1 concentrations in saliva from 36 healthy subjects and 33 periodontal patients were quantified using the CSP1 sandwich ELISA system, and the results were analyzed using the Student's t-test. Results: Immunoblot analysis using mAb-hCSP1 as a probe confirmed that CSP1 in human saliva existed as a single band with a molecular weight of approximately 27-kDa. The quantification of CSP1 concentrations by CSP1 ELISA showed that the median values (25th to 75th percentiles) of periodontal patients and healthy subjects were 9,474 ng/mL (range, 8,434.10,139 ng/mL) and 8,598 ng/mL (range, 7,421.9,877 ng/mL), respectively. The Student's t-test indicated the presence of a statistically significant difference between the 2 groups (P=0.024). Conclusions: The presence of a significant difference in CSP1 levels between healthy subjects and periodontal patients suggests that CSP1 may be a potential biomarker for the detection or screening of periodontitis patients.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.2
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• pp.169-176
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• 2017

Non-alcoholic fatty liver disease (NAFLD) is caused by chronic lipid accumulation due to dysregulation of lipid metabolism in the liver, and it is associated with various human diseases such as obesity, dyslipidemia, hypertension, and diabetes. Histone acetylation is a representative epigenetic mechanism regulated by histone acetyltransferases (HATs) and deacetylases. We observed that tartary buckwheat sprout (TBS) suppressed lipid accumulation in HepG2 cells through its anti-HAT activity. We showed that TBS was a novel HAT inhibitor with specificity for the major HAT enzyme p300. Importantly, TBS reduced acetylation of total and histone proteins, H3K9, H3K36, and H4K8, resulting in decreased transcriptional activities of sterol regulatory element-binding protein 1c, ATP citrate lyase, and fatty acid synthase. These results suggest that TBS inhibits the NAFLD transcription-modulating activity of lipogenesis-related genes through modification of histone acetylation.

• Journal of Life Science
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• v.20 no.10
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• pp.1451-1457
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• 2010

Serotonin (5-hydroxytryptamine, 5-HT) is an important mediator of cell-cell signaling in neuronal systems. The serotonin transporter (SERT) on the plasma membrane controls the extracellular 5-HT level by reuptake of released 5-HT from the synaptic cleft, but the underlying regulation mechanism is unclear. Here, we used the yeast two-hybrid system to identify the specific binding protein(s) that interacts with the carboxyl (C)-terminal region of SERT and found a specific interaction with protein kinase C-$\varepsilon$ (PKC-$\varepsilon$), a PKC isotype that is characterized as a calcium-independent and phorbol ester/diacylglycerol-sensitive serine/threonine kinase. PKC-$\varepsilon$ bound to the tail region of SERT but not to other members of the $Na^+/Cl^-$ dependent SLC6 gene family in the yeast two-hybrid assay. The C-terminal region of PKC-$\varepsilon$ is essential for interaction with SERT. In addition, these proteins showed specific interactions in the glutathione S-transferase (GST) pull-down assay. PKC-$\varepsilon$ phosphorylated the peptide of the SERT amino (N)-terminus in vitro. These results suggest that the phosphorylation of SERT by PKC-$\varepsilon$ may regulate SERT activity in plasma membrane.

• Journal of Life Science
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• v.30 no.5
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• pp.483-490
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• 2020

The ubiquitin system uses ligases and deubiquitinases (DUBs) to regulate ubiquitin position on protein substrates and is involved in many biological processes which determine stability, activity, and interaction of the target substrate. DUBs are classified in six groups according to catalytic domain, namely ubiquitin-specific proteases (USPs); ubiquitin C-terminal hydrolases (UCHs); ovarian tumor proteases (OTUs); Machado Joseph Disease proteases (MJDs); motif interacting with Ub (MIU)-containing novel DUB family (MINDY); and Jab1/MPN/MOV34 metalloenzymes (JAMMs). Otubain 1 (OTUB1) is a DUB in the OTU family which possesses both canonical and non-canonical activity and can regulate multiple cellular signaling pathways. In this review, we describe the function of OTUB1 through regulation of its canonical and non-canonical activities in multiple specifically cancer-associated pathways. The canonical activity of OTUB1 inhibits protein ubiquitination by cleaving Lys48 linkages while its non-canonical activity prevents ubiquitin transfer onto target proteins through binding to E2-conjugating enzymes, resulting in the induction of protein deubiquitination. OTUB1 can therefore canonically and non-canonically promote tumor cell proliferation, invasion, and drug resistance through regulating FOXM1, ERα, KRAS, p53, and mTORC1. Moreover, clinical research has demonstrated that OTUB1 overexpresses with high metastasis in many tumor types including breast, ovarian, esophageal squamous, and glioma. Therefore, OTUB1 has been suggested as a diagnosis marker and potential therapeutic target for oncotherapy.

• Journal of Life Science
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• v.13 no.5
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• pp.642-650
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• 2003

To develop a new approach to the treatment of neuroblastoma cells we evaluated the effect of cAMP on the Ewing's sarcoma cell line CHP-100. We observed that the proliferation-inhibitory effect of cAMP analogs was due to cell cycle arrest and induction of apoptosis, which was confirmed by observing the morphological changes and DNA fragmentation. DNA flow cytometric analysis revealed that cAMP arrested the cell cycle progression at the G1 phase, which effects were associated with inhibition of phosphorylation of retinoblastoma protein (pRB) and enhanced binding of pRB and the transcription factor E2F-1. cAMP also suppressed the cyclin-dependent kinase (Cdk) 2 and cyclin E-associated kinase activity without changes of their expressions. Furthermore, cAMP induced the levels of Cdk inhibitor $p21^{WAF1/CIP1$ expression and p21 proteins induced by cAMP were associated with Cdk2. Overall, our results identify a combined mechanism involving the inhibition of pRB phosphorylation and induction of p21 as targets for cAMP, and this may explain some of its anti-cancer effects.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.9
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• pp.3723-3727
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• 2015

The p53 tumor suppressor protein is a principal mediator of growth arrest, senescence, and apoptosis in response to a broad array of cellular damage. p53 is a substrate for the ubiquitin-proteasome system, however, the ubiquitin-conjugating enzymes (E2s) involved in p53 ubiquitination have not been well studied. UBE2Q1 is a novel E2 ubiquitin conjugating enzyme gene. Here, we investigated the effect of UBE2Q1 overexpression on the level of p53 in the MDA-MB-468 breast cancer cell line as well as the interaction between UBE2Q1 and p53. By using a lipofection method, the p53 mutated breast cancer cell line, MDA-MB-468, was transfected with the vector pCMV6-AN-GFP, containing UBE2Q1 ORF. Western blot analysis was employed to verify the overexpression of UBE2Q1 in MDA-MB-468 cells and to evaluate the expression level of p53 before and after cell transfection. Immunoprecipitation and GST pull-down protocols were used to investigate the binding of UBE2Q1 to p53. We established MDA-MB-468 cells that transiently expressed a GFP fusion proteins containing UBE2Q1 (GFP-UBE2Q1). Western blot analysis revealed that levels of p53 were markedly lower in UBE2Q1 transfected MDA-MB-468 cells as compared with control MDA-MB-468 cells. Both in vivo and in vitro data showed that UBE2Q1 co-precipitated with p53 protein. Our data for the first time showed that overexpression of UBE2Q1can lead to the repression of p53 in MDA-MB-468 cells. This repression of p53 may be due to its UBE2Q1 mediated ubiquitination and subsequent proteasome degradation, a process that may involve direct interaction of UBE2Q1with p53.

• Journal of Ginseng Research
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• v.7 no.2
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• pp.102-107
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• 1983

The effects of saponin, one of major components (Panax ginseng C.A. Meyer), on the growth of E. coli K-12 and the formation of siderphore was observed The following results were obtained. 1. When E. coli was grown on medium containing 1${\times}$10-5%-11${\times}$10-1% of the saponin, the rate of growth was stimulated at 10-1% of the saponin significantly compared to that of control. 2. When E. coli K-12 was grown on medium containing 1${\times}$10-1% of the saponin, the amount of siderphore was two times as much as the control. 3. The growth of E. coli was observed to be dependent on the concentration of siderophore when siderophore was added to medium. 4. The effect of saponin on the formation of siderophore in vitro was observed to reach maximum at 1${\times}$10-3% of the saponin. Such results suggest that the growth rate of E. coli K-12 could be enhanced by ginseng saponin fraction through stimulation of siderphore formation. We have described the fast growth of E. coli, K-12 and B. subtilis, rapid uptake of 14C-glucose, and high level of other metabolites such as lipids and proteins of E. coli, and B. subtilis in medium containing saponing fraction compared to that of microorganisms without saponin fraction.1∼3Such differences were claimed to be due to rapid uptake of 14C-glucose by widened periplasmic region throught unknown mechanism in the prescence of saponin fraction in medium3 and have raised a question whether there is another possible factor, siderophore4(Greek for iron bears), since microorganisms must secure a sufficient amount of iron for normal growth. These are known to be synthesized by the cells under iron-deficient condition and in most case, excreted into the medium5, where they can complex and solubilize any iron present there. It is generally believed that these complexes are then taken into the cells presumably by specific transport systems, thus providing iron for cell metabolism. Within the group of enteric bacteria, only three species (E. coli, S. typhimurium, and A. aerogense) have, so far, been studied in a ny detail. The main iron-binding compound produced by these species is enterochelin, and its role in iron transport is now well established. And biosynthesis of enterochelin from 2, 3- dihydroxybenzoate and serine in the prescence of magnesium ions and ATP was reported6. 2, 3-dihydroxybenzoate was also shown to involve isochorismate and 2, 3-dihydro-2, 3-dihydroxybenzoate as intermediate.7∼11 The present paper deals with the effect of ginseng saponin fraction on growth, the level of enterochelin formation in vivo and the conversion of 2, 3-dihydroxybenzoate and serine into entrochelin in vitro, and entrochelin obtained on the growth in relation to possible explanation of ginseng saponin fraction on the rapid growth of E. coli, K-12.