• BMB Reports
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• 제43권6호
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• pp.438-444
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• 2010

Dnd (dead end) gene encodes an RNA binding protein and is specifically expressed in primordial germ cells (PGCs) as a vertebrate-specific component of the germ plasma throughout embryogenesis. By utilizing a technique of specific nucleic acids associated with proteins (SNAAP), 13 potential target mRNAs of zebrafish Dnd (ZDnd) protein were identified from 8-cell embryo, and 8 target mRNAs have been confirmed using an RT-PCR analysis. Of the target mRNAs, the present study is focused on the regulation of geminin, which is an inhibitor of DNA replication. Using electrophoretic mobility shift assay (EMSA), we demonstrated that ZDND protein bound the 67-nucleotide region from 864 to 931 in the 3'UTR of geminin mRNA, a sequence containing 60.29% of uridine. Results from a dual-luciferase assay in HEK293 cells showed that ZDND increases the translation of geminin. Taken together, the identification of target mRNA for ZDnd will be helpful to further explore the biological function of Dnd in zebrafish germ-line development as well as in cancer cells.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2001년도 추계학술대회 및 정기총회
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• pp.108-108
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• 2001

Axin2/Conductin/Axil and its ortholog Axin are negative regulators of the Wnt signaling pathway, which promote the phosphorylation and degradation of ${\beta}$-catenin. While Axin is expressed ubiquitously, Axin2 mRNA was seen in a restricted pattern during mouse embryogenesis and organogenesis. Because many sites of Axin2 expression overlapped with those of several Wnt genes, we tested whether Axin2 was induced by Wnt signaling. Endogenous Axin2 mRNA and protein expression could be rapidly induced by activation of the Wnt pathway, and Axin2 reporter constructs, containing a 5.6 kb DNA fragment including the promoter and first intron, were also induced. This genomic region contains eight Tcf/LEF consensus binding sites, five of which are located within longer, highly conserved non-coding sequences. The mutation or deletion of these Tcf/LEF sites greatly diminished induction by ${\beta}$-catenin, and mutation of the Tcf/LEF site T2 abolished protein binding in an electrophoretic mobility-shift assay. These results strongly suggest that Axin2 is a direct target of the Wnt pathway, mediated through Tcf/LEF factors. The 5.6 kb genomic sequence was sufficient to direct the tissue specific expression of d2EGFP in transgenic embryos, consistent with a role for the Tcf/LEF sites and surrounding conserved sequences in the in vivo expression pattern of Axin2. Our results suggest that Axin2 participates in a negative feedback loop, which could serve to limit the duration or intensity of a Wnt-initiated signal.

• Journal of Plant Biotechnology
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• 제36권1호
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• pp.53-58
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• 2009

Calcium signals can be transduced by binding calmodulin (CaM), a $Ca^{2+}$ sensor in eukaryotes, is known to be involved in the regulation of diverse cellular functions. We isolated a CaM-binding protein 63 kD (AtCBP63) from the pathogen-treated Arabidopsis cDNA expression library. Recently, AtCBP63 was identified as a CaM bining protein. The CaM binding domain of AtCBP63 was reported to be located in its N-terminal region, In this study, however, we showed that ACaM2 could specifically bind to second CaM-binding domain (CaMBD) of AtCBP63 at the C-terminal region. The specific binding of CaM to CaM binding domain was confirmed by a gel mobility shift assay, a split ubiquitin assay, site-directed mutagenesis, and a competition assay using a $Ca^{2+}$/CaM-dependent enzyme. The gene expression of AtCBP63 was induced by pathogens and pathogens related second messengers. This result suggests that a CaM binding protein, AtCBP63, may play role in pathogen defense signaling pathway.

• Asian Pacific Journal of Cancer Prevention
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• 제14권5호
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• pp.3309-3314
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• 2013

Spleen tyrosine kinase (SYK) is a non-receptor type cytoplasmic protein and a known tumor suppressor gene in breast cancer. Polymorphisms in SYK have been reported to be associated with cell invasion/cell morality and an increased risk of cancer development. In this case control study, all exons of the SYK gene and its exon/ intron boundaries were amplified in 200 breast cancer cases and 100 matched controls and then analyzed by single stranded conformational polymorphism. Amplified products showing altered mobility patterns were sequenced and analyzed. Twelve variations were identified in exonic and intronic regions of DNA encoding SH2 domain and kinase domain of the SYK gene. All of these mutations are novel. Among them, 5 missense mutations were observed in exon 15 while one missense mutation was found in exon 8. In addition to these mutations, six mutations were also identified in intronic regions. We found a significant association between SYK mutations and breast cancer and observed that Glu241Arg, a missense mutation is associated with an increase risk of ~7 fold (OR=6.7, 95% CI=1.54-28.8), Thr581Pro (missense mutation) is associated with increased risk of ~16 fold (OR=15.5, 95%CI=2.07-115.45) and 63367 T>G (missense mutation) is associated with increased risk of ~13 fold (OR=12.8, 95%CI=1.71-96.71) for breast cancer. Significant associations were observed for each of these variations with both late menopause (p<0.01) and early menarche (p<0.005) cases when compared to controls. Our findings suggest that the polymorphic gene SYK may contribute to the development of breast cancer in at least the Pakistani population. This study provides an insight view of SYK which may provide a significant finding for the pharmaceutical and biotechnology industry.

• Natural Product Sciences
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• 제17권3호
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• pp.250-255
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• 2011

The immune system is finely balanced by the activities of pro-inflammatory and anti-inflammatory mediators or cytokines. Unregulated activities of these mediators can lead to the development of various inflammatory diseases. A variety of safe and effective anti-inflammatory agents are available with many more drugs under development. Of the natural compounds, the sesquiterpenes (nootkatone, ${\alpha}$-cyperone, valencene and ${\alpha}$-selinene) isolated from C. rotundus L. have received much attention because of their potential antiinflammatory effects. However, limited studies have been reported regarding the influence of sesquiterpene structure on anti-inflammatory activity. In the present study, the anti-inflammatory potential of four structurally divergent sesquiterpenes was evaluated in lipopolysaccaride (LPS)-stimulated RAW 264.7 cells, murine macrophages. Among the four sesquiterpenes, ${\alpha}$-cyperone and nootkatone, showed stronger anti-inflammatory and a potent NF-${\kappa}B$ inhibitory effect on LPS-stimulated RAW 264.7 cells. Molecular analysis revealed that various inflammatory enzymes (iNOS and COX-2) were reduced significantly and this correlated with downregulation of the NF-${\kappa}B$ signaling pathway. Additionally, electrophoretic mobility shift assays (EMSA) elucidated that nootkatone and ${\alpha}$-cyperone dramatically suppressed LPS-induced NF-${\kappa}B$-DNA binding activity using 32Plabeled NF-${\kappa}B$ probe. Hence, our data suggest that ${\alpha}$-cyperone and nootkatone are potential therapeutic agents for inflammatory diseases.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.21-21
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• 2011

A series of Quasi-Elastic Neutron Scattering (QENS) experiments helps us to understand the single-particle (hydrogen atom) dynamics of a globular protein and its hydration water and strong coupling between them. We also performed Molecular Dynamics (MD) simulations on a realistic model of the hydrated hen-egg Lysozyme powder having two proteins in the periodic box. We found the existence of a Fragile-to-Strong dynamic Crossover (FSC) phenomenon in hydration water around a protein occurring at TL=$225{\pm}5K$ by analyzing Intermediate Scattering Function (ISF). On lowering of the temperature toward FSC, the structure of hydration water makes a transition from predominantly the High Density Liquid (HDL) form, a more fluid state, to predominantly the Low Density Liquid (LDL) form, a less fluid state, derived from the existence of a liquid?liquid critical point at an elevated pressure. We showed experimentally and confirmed theoretically that this sudden switch in the mobility of the hydration water around a protein triggers the dynamic transition (so-called glass transition) of the protein, at a temperature TD=220 K. Mean Square Displacement (MSD) is the important factor to show that the FSC is the key to the strong coupling between a protein and its hydration water by suggesting TL${\fallingdotseq}$TD. MD simulations with TIP4P force field for water were performed to understand hydration level dependency of the FSC temperature. We added water molecules to increase hydration level of the protein hydration water, from 0.30, 0.45, 0.60 and 1.00 (1.00 is the bulk water). These confirm the existence of the FSC and the hydration level dependence of the FSC temperature: FSC temperature is decreased upon increasing hydration level. We compared the hydration water around Lysozyme, B-DNA and RNA. Similarity among those suggests that the FSC and this coupling be universal for globular proteins, biopolymers.

• Molecules and Cells
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• 제22권3호
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• pp.328-335
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• 2006

Imperatoxin A ($IpTx_a$), a 3.7 kDa peptide from the African scorpion Pandinus imperator, is an agonist of the skeletal muscle ryanodine receptor (RyR1). In order to study the structure of the toxin and its effect on RyR1, $IpTx_a$ cDNA was PCR-amplified using 3 pairs of primers, and the toxin was expressed in E. coli. The toxin was further purified by chromatography, and various point mutants in which basic amino acids were substituted by alanine were prepared by site-directed mutagenesis. Studies of single channel properties by the planar lipid bilayer method showed that the recombinant $IpTx_a$ was identical to the synthetic $IpTx_a$ with respect to high-performance liquid chromatography mobility, amino acid composition and specific effects on RyR1. Mutations of certain basic amino acids ($Lys^{19}$, $Arg^{23}$, and $Arg^{33}$) dramatically reduced the capacity of the peptide to activate RyRs. A subconductance state predominated when $Lys^8$ was substituted with alanine. These results suggest that some basic amino acid residues in $IpTx_a$ are important for activation of RyR1, and that $Lys^8$ plays an important role in regulating the gating mode of RyR1.

• Journal of Microbiology and Biotechnology
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• 제18권5호
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• pp.837-844
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• 2008

Glucose (xylose) isomerases from Streptomyces sp. have been used for the production of high fructose corn syrup for industrial purposes. An 11-kb DNA fragment containing the xyl gene cluster was isolated from Streptomyces lividans TK24 and its nucleotide sequences were analyzed. It was found that the xyl gene cluster contained a putative transcriptional repressor (xylR), xylulokinase (xylB), and xylose isomerase (xylA) genes. The transcriptional directions of the xylB and xylA genes were divergent, which is consistent to those found in other streptomycetes. A gene encoding XylR was located downstream of the xylB gene in the same direction, and its mutant strain produced xylose isomerase regardless of xylose in the media. The enzyme expression level in the mutant was 4.6 times higher than that in the parent strain under xylose-induced condition. Even in the absence of xylose, the mutant strain produce over 60% of enzyme compared with the xylose-induced condition. Gel mobility shift assay showed that XylR was able to bind to the putative xyl promoter, and its binding was inhibited by the addition of xylose in vitro. This result suggested that XylR acts as a repressor in the S. lividans xylose operon.

• Molecules and Cells
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• 제23권3호
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• pp.398-404
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• 2007

Cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) are involved in various pathophysiological processes such as inflammation and carcinogenesis. In a search for inhibitors of COX-2 and iNOS production we found that extracts of Stewartia koreana strongly inhibited NO and $PGE_2$ production in LPS-treated macrophage RAW 264.7 cells. We have now shown that the mRNA and protein levels of iNOS and COX-2 are reduced by the Stewartia koreana extract (SKE). SKE inhibited expression of an NF-${\kappa}B$ reporter gene in response to LPS, and gel mobility shift assays revealed that SKE reduced NF-${\kappa}B$ DNA-binding activity. The extract also inhibited LPS-induced phosphorylation of $I{\kappa}B-{\alpha}$ and nuclear translocation of p65. Administration of the extract reduced the symptoms of arthritis in a collagen-induced arthritic mouse model. These results indicate that Stewartia extracts contain potentially useful agents for preventing and treating inflammatory diseases.

• Journal of Microbiology and Biotechnology
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• 제32권9호
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• pp.1134-1145
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• 2022

SCO6993 (606 amino acids) in Streptomyces coelicolor belongs to the large ATP-binding regulators of the LuxR family regulators having one DNA-binding motif. Our previous findings predicted that SCO6993 may suppress the production of pigmented antibiotics, actinorhodin, and undecylprodigiosin, in S. coelicolor, resulting in the characterization of its properties at the molecular level. SCO6993-disruptant, S. coelicolor ΔSCO6993 produced excess pigments in R2YE plates as early as the third day of culture and showed 9.0-fold and 1.8-fold increased production of actinorhodin and undecylprodigiosin in R2YE broth, respectively, compared with that by the wild strain and S. coelicolor ΔSCO6993/SCO6993⁺. Real-time polymerase chain reaction analysis showed that the transcription of actA and actII-ORF4 in the actinorhodin biosynthetic gene cluster and that of redD and redQ in the undecylprodigiosin biosynthetic gene cluster were significantly increased by SCO6993-disruptant. Electrophoretic mobility shift assay and DNase footprinting analysis confirmed that SCO6993 protein could bind only to the promoters of pathway-specific transcriptional activator genes, actII-ORF4 and redD, and a specific palindromic sequence is essential for SCO6993 binding. Moreover, SCO6993 bound to two palindromic sequences on its promoter region. These results indicate that SCO6993 suppresses the expression of other biosynthetic genes in the cluster by repressing the transcription of actII-ORF4 and redD and consequently negatively regulating antibiotic production.