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71.
Jung Hwan Yoon Mi La Cho Yoo Jin Choi Ji Yeon Back Mi Kyung Park Suk Woo Lee Byung Joon Choi Hassan Ashktorab Duane T. Smoot Suk Woo Nam Jung Young Lee Won Sang Park 《Journal of cellular biochemistry》2013,114(8):1800-1809
Gastrokine 1 (GKN1) plays an important role in the gastric mucosal defense mechanism and also acts as a functional gastric tumor suppressor. In this study, we examined the effect of GKN1 on the expression of inflammatory mediators, including NF‐κB, COX‐2, and cytokines in GKN1‐transfected AGS cells and shGKN1‐transfected HFE‐145 cells. Lymphocyte migration and cell viability were also analyzed after treatment with GKN1 and inflammatory cytokines in AGS cells by transwell chemotaxis and an MTT assay, respectively. In GKN1‐transfected AGS cells, we observed inactivation and reduced expression of NF‐κB and COX‐2, whereas shGKN1‐transfected HFE‐145 cells showed activation and increased expression of NF‐κB and COX‐2. GKN1 expression induced production of inflammatory cytokines including IL‐8 and ‐17A, but decreased expression of IL‐6 and ‐10. We also found IL‐17A expression in 9 (13.6%) out of 166 gastric cancer tissues and its expression was closely associated with GKN1 expression. GKN1 also acted as a chemoattractant for the migration of Jurkat T cells and peripheral B lymphocytes in the transwell assay. In addition, GKN1 significantly reduced cell viability in both AGS and HFE‐145 cells. These data suggest that the GKN1 gene may inhibit progression of gastric epithelial cells to cancer cells by regulating NF‐κB signaling pathway and cytokine expression. J. Cell. Biochem. 114: 1800–1809, 2013. © 2013 Wiley Periodicals, Inc. 相似文献
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73.
Sohee Baek Nam Joo Kang Grzegorz M. Popowicz Marcelino Arciniega Sung Keun Jung Sanguine Byun Nu Ry Song Yong-Seok Heo Bo Yeon Kim Hyong Joo Lee Tad A. Holak Martin Augustin Ann M. Bode Robert Huber Zigang Dong Ki Won Lee 《Journal of molecular biology》2013,425(2):411-423
c-Jun NH2-terminal kinases (JNKs) and phosphatidylinositol 3-kinase (PI3-K) play critical roles in chronic diseases such as cancer, type II diabetes, and obesity. We describe here the binding of quercetagetin (3,3′,4′,5,6,7-hydroxyflavone), related flavonoids, and SP600125 to JNK1 and PI3-K by ATP-competitive and immobilized metal ion affinity-based fluorescence polarization assays and measure the effect of quercetagetin on JNK1 and PI3-K activities. Quercetagetin attenuated the phosphorylation of c-Jun and AKT, suppressed AP-1 and NF-κB promoter activities, and also reduced cell transformation. It attenuated tumor incidence and reduced tumor volumes in a two-stage skin carcinogenesis mouse model.Our crystallographic structure determination data show that quercetagetin binds to the ATP-binding site of JNK1. Notably, the interaction between Lys55, Asp169, and Glu73 of JNK1 and the catechol moiety of quercetagetin reorients the N-terminal lobe of JNK1, thereby improving compatibility of the ligand with its binding site. The results of a theoretical docking study suggest a binding mode of PI3-K with the hydroxyl groups of the catechol moiety forming hydrogen bonds with the side chains of Asp964 and Asp841 in the p110γ catalytic subunit. These interactions could contribute to the high inhibitory activity of quercetagetin against PI3-K. Our study suggests the potential use of quercetagetin in the prevention or therapy of cancer and other chronic diseases. 相似文献
74.
Ok Tae Kim Nam Hee Yoo Gum Soog Kim Young Chang Kim Kyong Hwan Bang Dong Yun Hyun Seung Hye Kim Min Young Kim 《Plant Cell, Tissue and Organ Culture》2013,112(1):87-93
It has been recognized that ginsenoside Rg3 is not naturally produced in ginseng although this ginsenoside can accumulate in red ginseng as the result of a thermal process. In order to determine whether or not Rg3 is synthesized in ginseng, hairy roots were treated with methyl jasmonate (MJ). From HPLC analysis, no peak for Rg3 was observed in the controls. However, Rg3 did accumulate in hairy roots that were MJ-treated for 7?days. Rg3 content was 0.42?mg/g (dry weight). To gain more insight into the effects of MJ on UDP-glucosyltransferase (UGT) activity, we attempted to evaluate ginsenoside Rg3 biosynthesis by UGT. A new peak for putative Rg3 was observed, which was confirmed by LC-MS/MS analysis. Our findings indicate that the proteins extracted from our hairy root lines can catalyze Rg3 from Rh2. This suggests that our ginseng hairy root lines possess Rg3 biosynthesis capacity. 相似文献
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76.
Krishna Nath Bong-Kwan Phee Suyeong Jeong Sun Yi Lee Yoshio Tateno Suleyman I. Allakhverdiev Choon-Hwan Lee Hong Gil Nam 《Photosynthesis research》2013,117(1-3):547-556
Photosynthetic complexes in the thylakoid membrane of plant leaves primarily function as energy-harvesting machinery during the growth period. However, leaves undergo developmental and functional transitions along aging and, at the senescence stage, these complexes become major sources for nutrients to be remobilized to other organs such as developing seeds. Here, we investigated age-dependent changes in the functions and compositions of photosynthetic complexes during natural leaf senescence in Arabidopsis thaliana. We found that Chl a/b ratios decreased during the natural leaf senescence along with decrease of the total chlorophyll content. The photosynthetic parameters measured by the chlorophyll fluorescence, photochemical efficiency (F v/F m) of photosystem II, non-photochemical quenching, and the electron transfer rate, showed a differential decline in the senescing part of the leaves. The CO2 assimilation rate and the activity of PSI activity measured from whole senescing leaves remained relatively intact until 28 days of leaf age but declined sharply thereafter. Examination of the behaviors of the individual components in the photosynthetic complex showed that the components on the whole are decreased, but again showed differential decline during leaf senescence. Notably, D1, a PSII reaction center protein, was almost not present but PsaA/B, a PSI reaction center protein is still remained at the senescence stage. Taken together, our results indicate that the compositions and structures of the photosynthetic complexes are differentially utilized at different stages of leaf, but the most dramatic change was observed at the senescence stage, possibly to comply with the physiological states of the senescence process. 相似文献
77.
Won-Heong Lee Jin-Woo Kim Eun-Hee Park Nam Soo Han Myoung-Dong Kim Jin-Ho Seo 《Applied microbiology and biotechnology》2013,97(4):1561-1569
Sufficient supply of NADPH is one of the most important factors affecting the productivity of biotransformation processes. In this study, construction of an efficient NADPH-regenerating system was attempted using direct phosphorylation of NADH by NADH kinase (Pos5p) from Saccharomyces cerevisiae for producing guanosine diphosphate (GDP)-l-fucose and ε-caprolactone in recombinant Escherichia coli. Expression of Pos5p in a fed-batch culture of recombinant E. coli producing GDP-l-fucose resulted in a maximum GDP-l-fucose concentration of 291.5 mg/l, which corresponded to a 51 % enhancement compared with the control strain. In a fed-batch Baeyer–Villiger (BV) oxidation of cyclohexanone using recombinant E. coli expressing Pos5p, a maximum ε-caprolactone concentration of 21.6 g/l was obtained, which corresponded to a 96 % enhancement compared with the control strain. Such an increase might be due to the enhanced availability of NADPH in recombinant E. coli expressing Pos5p. These results suggested that efficient regeneration of NADPH was possible by functional expression of Pos5p in recombinant E. coli, which can be applied to other NADPH-dependent biotransformation processes in E. coli. 相似文献
78.
In Jung Kim Hyeok-Jin Ko Tae-Wan Kim Ki Hyun Nam In-Geol Choi Kyoung Heon Kim 《Applied microbiology and biotechnology》2013,97(12):5381-5388
BsEXLX1 from Bacillus subtilis is the first discovered bacterial expansin as a structural homolog of a plant expansin, and it exhibited synergism with cellulase on the cellulose hydrolysis in a previous study. In this study, binding characteristics of BsEXLX1 were investigated using pretreated and untreated Miscanthus x giganteus in comparison with those of CtCBD3, a cellulose-binding domain from Clostridium thermocellum. The amounts of BsEXLX1 bound to cellulose-rich substrates were significantly lower than those of CtCBD3. However, the amounts of BsEXLX1 bound to lignin-rich substrates were much higher than those of CtCBD3. A binding competition assay between BsEXLX1 and CtCBD3 revealed that binding of BsEXLX1 to alkali lignin was not affected by the presence of CtCBD3. This preferential binding of BsEXLX1 to lignin could be related to root colonization in plants by bacteria, and the bacterial expansin could be used as a lignin blocker in the enzymatic hydrolysis of lignocellulose. 相似文献
79.
Long Liu Yanfeng Liu Hyun-dong Shin Rachel R. Chen Nam Sun Wang Jianghua Li Guocheng Du Jian Chen 《Applied microbiology and biotechnology》2013,97(14):6113-6127
Increasing concerns over limited petroleum resources and associated environmental problems are motivating the development of efficient cell factories to produce chemicals, fuels, and materials from renewable resources in an environmentally sustainable economical manner. Bacillus spp., the best characterized Gram-positive bacteria, possesses unique advantages as a host for producing microbial enzymes and industrially important biochemicals. With appropriate modifications to heterologous protein expression and metabolic engineering, Bacillus species are favorable industrial candidates for efficiently converting renewable resources to microbial enzymes, fine chemicals, bulk chemicals, and fuels. Here, we summarize the recent advances in developing Bacillus spp. as a cell factory. We review the available genetic tools, engineering strategies, genome sequence, genome-scale structure models, proteome, and secretion pathways, and we list successful examples of enzymes and industrially important biochemicals produced by Bacillus spp. Furthermore, we highlight the limitations and challenges in developing Bacillus spp. as a robust and efficient production host, and we discuss in the context of systems and synthetic biology the emerging opportunities and future research prospects in developing Bacillus spp. as a microbial cell factory. 相似文献
80.
Genetic localization and in vivo characterization of a Monascus azaphilone pigment biosynthetic gene cluster 总被引:1,自引:0,他引:1