• Journal of Microbiology
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• 제43권6호
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• pp.475-486
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• 2005

Fungal secondary metabolites constitute a wide variety of compounds which either playa vital role in agricultural, pharmaceutical and industrial contexts, or have devastating effects on agriculture, animal and human affairs by virtue of their toxigenicity. Owing to their beneficial and deleterious characteristics, these complex compounds and the genes responsible for their synthesis have been the subjects of extensive investigation by microbiologists and pharmacologists. A majority of the fungal secondary metabolic genes are classified as type I polyketide synthases (PKS) which are often clustered with other secondary metabolism related genes. In this review we discuss on the significance of our recent discovery of chalcone synthase (CHS) genes belonging to the type III PKS superfamily in an industrially important fungus, Aspergillus oryzae. CHS genes are known to playa vital role in the biosynthesis of flavonoids in plants. A comparative genome analyses revealed the unique character of A. oryzae with four CHS-like genes (csyA, csyB, csyC and csyD) amongst other Aspergilli (Aspergillus nidulans and Aspergillus fumigatus) which contained none of the CHS-like genes. Some other fungi such as Neurospora crassa, Fusarium graminearum, Magnaporthe grisea, Podospora anserina and Phanerochaete chrysosporium also contained putative type III PKSs, with a phylogenic distinction from bacteria and plants. The enzymatically active nature of these newly discovered homologues is expected owing to the conservation in the catalytic residues across the different species of plants and fungi, and also by the fact that a majority of these genes (csyA, csyB and csyD) were expressed in A. oryzae. While this finding brings filamentous fungi closer to plants and bacteria which until recently were the only ones considered to possess the type III PKSs, the presence of putative genes encoding other principal enzymes involved in the phenylpropanoid and flavonoid biosynthesis (viz., phenylalanine ammonia-lyase, cinnamic acid hydroxylase and p-coumarate CoA ligase) in the A. oryzae genome undoubtedly prove the extent of its metabolic diversity. Since many of these genes have not been identified earlier, knowledge on their corresponding products or activities remain undeciphered. In future, it is anticipated that these enzymes may be reasonable targets for metabolic engineering in fungi to produce agriculturally and nutritionally important metabolites.

• Biomolecules & Therapeutics
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• 제22권5호
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• pp.390-399
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• 2014

Chalcones (1,3-diaryl-2-propen-1-ones), a flavonoid subfamily, are widely known for their anti-inflammatory properties. Propenone moiety in chalcones is known to play an important role in generating biological responses by chalcones. In the present study, we synthesized chalcone derivatives structurally modified in propenone moiety and examined inhibitory effect on nitric oxide (NO) production and its potential mechanisms. Among the chalcone derivatives used for this study, TI-I-174 (3-(2-Hydroxyphenyl)-1-(thiophen-3-yl)prop-2-en-1-one) most potently inhibited lipopolysaccharide (LPS)-stimulated nitrite production in RAW 264.7 macrophages. TI-I-174 treatment also markedly inhibited inducible nitric oxide synthase (iNOS) expression. However, TI-I-174 did not significantly affect production of IL-6, cyclooxygenase-2 (COX-2) and tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), implying that TI-I-174 inhibits production of inflammatory mediators in a selective manner. Treatment of macrophages with TI-I-174 significantly inhibited transcriptional activity of activator protein-1 (AP-1) as determined by luciferase reporter gene assay, whereas nuclear factor-${\kappa}B$ (NF-${\kappa}B$) activity was not affected by TI-I-1744. In addition, TI-I-174 significantly inhibited activation of c-Jun-N-Terminal kinase (JNK) without affecting ERK1/2 and p38MAPK, indicating that down-regulation of iNOS gene expression by TI-I-174 is mainly attributed by blockade of JNK/AP-1 activation. We also demonstrated that TI-I-174 treatment led to an increase in heme oxygenase-1 (HO-1) expression both at mRNA and protein level. Transfection of siRNA targeting HO-1 reversed TI-I-174-mediated inhibition of nitrite production. Taken together, these results indicate that TI-I-174 suppresses NO production in LPS-stimulated RAW 264.7 macrophages via induction of HO-1 and blockade of AP-1 activation.

• 생명과학회지
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• 제29권10호
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• pp.1055-1061
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• 2019

식충식물(carnivorous plant)인 Sarracenia purpurea는 생육에 있어 매우 높은 수준의 광량을 필요로 하며 색, 과즙 등으로 벌레를 유인하여 영양분을 흡수하는 것으로 알려져 있다. S. purpurea는 약한 빛 조건에서 녹색을 띄었으며 강한 빛 조건에서는 잎을 포함한 포충낭 전체가 검붉은 색으로 변화하였다. 이와 같은 색의 변화는 질소비료를 첨가하였을 때에 관찰되지 않았다. S. purpurea를 붉게 물들이는 색소는 안토시아닌(anthocyanin)인 것으로 보고된 바가 있다. 본 연구에서는 빛의 세기와 질소 첨가에 따른 안토시아닌의 함량과 생합성 관련 유전자의 발현 특성을 분석하였다. $240{\mu}mol\;m^{-2}s^{-1}$의 강한 빛 조건에서의 안토시아닌 함량은 $40{\mu}mol\;m^{-2}s^{-1}$의 약한 빛에서 보다 6.15배 높았으며, 0.8% 요소 비료로 질소를 첨가하였을 때에는 약한 빛 조건과 큰 차이가 없었다. 안토시아닌의 초기 생합성 과정에 관여하는 CHALCONE SYNTHASE (CHS) 유전자는 강한 빛에서 발현이 증가하였고 질소 양분을 첨가하였을 때에 감소하였다. 이상의 결과는 빛과 토양의 환경 변화가 S. purpurea의 안토시아닌의 함량을 조절한다는 것을 보여주고 있다.

• Journal of Plant Biotechnology
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• 제36권4호
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• pp.415-422
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• 2009

This study aimed to develop carnation cultivars with new coloring system. We used four genes of Petunia hybrida - chalcone synthase (CHS), flavanone 3-hydroxylase (FHT), dihydroflavonol 4-reductase (DFR), and anthocyanidin synthase (ANS) - as probes, in order to isolate four genes from carnations (Dianthus Caryophyllus). The isolated genes were used as probes in order to select mutants out of collected carnations, using Northern blot analysis. The Northern blot analysis revealed 10 DFR mutants - Gumbyul, Eunbyul, Ballatyne, Crystal, Eugenia, Koreno, Imp. White Sim, West Crystal, White Alpine, and White Charotte. Six among the selected 10 cultivarswere excluded from the target cultivars, because Eugenia, Imp. White Sim, and White Alpine were proved to be double mutants of DFR and ANS, Koreno was considered to be a double mutant of DFR and CHS, and Gumbyul and Ballatyne were proved to be double mutants of DFR and CHI (Chalcone isomerase). Consequently, we selected five DFR mutants, including Virginie, which was already selected as a DFR mutant. Finally, we measured DFR activities in order to confirm the selection, and the results showed that all of the five cultivars - Eunbyul, Crystal, West Crystal, White Charotte, and Virginie - had got no DFR activity.

• 생명과학회지
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• 제18권2호
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• pp.234-240
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• 2008

매향' 딸기의 안토시아닌 생합성은 개화 후 26일째 시작되어 과실의 성숙기 동안 계속된다. 딸기로부터 안토시아닌의 생합성에 관여하는 주요 유전자를 분리하였다. 각각의 유전자에 대해, 다양한 식물체의 유사 유전자의 염기서열을 비교하여 PCR (polymerase chain reaciton) primer를 제작하였다. 숙기의 딸기에서 분리된 total RNA로부터 합성된 CDNA와 각 primer를 이용하여 RT (reverse transcriptase)-PCR을 수행하였다. 각 CDNA clone의 염기서열을 작성하여 분석한 결과, 이들은 안토시아닌 생합성에 관여하는 phenylalanine ammonia lyase (PAL), 4-cummarate CoA ligase (4CL), chalcone synthase (CHS), chalcone isomerase (CHI), flavanone-3-hydroxylase (F3H), dihydroflavonol 4-reductase (DFR), anthocyanidine synthase (ANS) 그리고 UDP-glucose:flavonoid-3-O-glucosyltransferase (UFGT) 효소에 해당되었다. Northern blot 분석 결과, 이들 유전자는 과실 발달과정에서 시기적으로 조절되었다. 특히 PAL을 제외한 모든 유전자는 과실에서만 주로 발현되었다. PAL, DFR 그리고 ANS유전자는 과실 초기 발달 단계인 개화 후 10일에 검출된 후 감소하다가, 22일에 다시 증가하기 시작하여 34일에 최대가 되었다. 한편, 다른 유전자들은 초기에는 발현되지 않다가, 안토시아닌이 축적되기 시작하는 개화 후 $22{\sim}30$일에 처음으로 검출되었다. 본 연구를 통해, 딸기 과실 발달과정에서 안토시아닌 생합성 과정에 관여하는 여러 유전자가 과실 숙기에 함께 조절되는 현상을 알 수 있다. 이러한 연구 결과는 안토시아닌 합성과정을 제어하는 조절 유전자가 존재한다는 것을 시사한다. 그리고 딸기의 안토시아닌 생합성 유전자의 발현패턴을 크게 두 가지로 나눌 수 있는 것으로 보아, 딸기의 안토시아닌 생합성에는 적어도 두 가지 서로 다른 조절 기작이 관여하여 색소 발달 과정을 제어할 것으로 보인다.

• 대한의생명과학회지
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• 제24권2호
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• pp.102-107
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• 2018

Toll-like receptors (TLRs) play an important role for host defense against invading pathogens. The activation of TLRs signaling leads to the activation of $NF-{\kappa}B$ and the expression of pro-inflammatory gene products such as cytokines and inducible nitric oxide synthase (iNOS). To evaluate the therapeutic potential of cardamonin, which is a naturally occurring chalcone from Alpinia species (zingiberaceous plant species), $NF-{\kappa}B$ activation and iNOS expression induced by MALP-2 (TLR2 and TLR6 agonist) or LPS (TLR4 agonist) were examined. Cardamonin inhibited the activation of $NF-{\kappa}B$ induced by MALP-2 or LPS. Cardamonin also suppressed the iNOS expression induced by MALP-2 or LPS. These results suggest that cardamonin has the specific mechanism for anti-inflammatory responses by regulating of TLRs signaling pathway.

• Molecules and Cells
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• 제25권2호
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• pp.247-252
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• 2008

There are several branch points in the flavonoid synthesis pathway starting from chalcone. Among them, the hydroxylation of flavanone is a key step leading to flavonol and anthocyanin. The flavanone 3-${\beta}$-hydroxylase (GmF3H) gene was cloned from soybean (Glycine max cultivar Sinpaldal) and shown to convert eriodictyol and naringenin into taxifolin and dihydrokaempferol, respectively. The major flavonoids in this soybean cultivar were found by LC-MS/MS to be kamepferol O-triglycosides and O-diglycosides. Expression of GmF3H and flavonol synthase (GmFLS) was induced by ultraviolet-B (UV-B) irradiation and their expression stimulated accumulation of kaempferol glycones. Thus, GmF3H and GmFLS appear to be key enzymes in the biosynthesis of the UV-protectant, kaempferol.

• Biomolecules & Therapeutics
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• 제24권6호
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• pp.595-603
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• 2016

(E)-3-Phenyl-1-(2-pyrrolyl)-2-propenone (PPP) is a pyrrole derivative of chalcone, in which the B-ring of chalcone linked to ${\beta}$-carbon is replaced by pyrrole group. While pyrrole has been studied for possible Src inhibition activity, chalcone, especially the substituents on the B-ring, has shown pharmaceutical, anti-inflammatory, and anti-oxidant properties via inhibition of NF-${\kappa}B$ activity. Our study is aimed to investigate whether this novel synthetic compound retains or enhances the pharmaceutically beneficial activities from the both structures. For this purpose, inflammatory responses of lipopolysaccharide (LPS)-treated RAW264.7 cells were analyzed. Nitric oxide (NO) production, inducible NO synthase (iNOS) and tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) mRNA expression, and the intracellular inflammatory signaling cascade were measured. Interestingly, PPP strongly inhibited NO release in a dose-dependent manner. To further investigate this anti-inflammatory activity, we identified molecular pathways by immunoblot analyses of nuclear fractions and whole cell lysates prepared from LPS-stimulated RAW264.7 cells with or without PPP pretreatment. The nuclear levels of p50, c-Jun, and c-Fos were significantly inhibited when cells were exposed to PPP. Moreover, according to the luciferase reporter gene assay after cotransfection with either TRIF or MyD88 in HEK293 cells, NF-${\kappa}B$-mediated luciferase activity dose-dependently diminished. Additionally, it was confirmed that PPP dampens the upstream signaling cascade of NF-${\kappa}B$ and AP-1 activation. Thus, PPP inhibited Syk, Src, and TAK1 activities induced by LPS or induced by overexpression of these genes. Therefore, our results suggest that PPP displays anti-inflammatory activity via inhibition of Syk, Src, and TAK1 activity, which may be developed as a novel anti-inflammatory drug.

• Molecules and Cells
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• 제19권1호
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• pp.67-73
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• 2005

Isoflavones are synthesized by isoflavone synthases via the phenylpropanoid pathway in legumes. We have cloned two isoflavone synthase genes, IFS1 and IFS2, from a total of 18 soybean cultivars. The amino acid residues of the proteins that differed between cultivars were dispersed over the entire coding region. However, amino acid sequence variation did not occur in conserved domains such as the ERR triad region, except that one conserved amino acid was changed in the IFS2 protein of the GS12 cultivar ($R_{374}G$) and the IFS1 proteins of the 99M06 and Soja99s65 cultivars ($A_{109}T$, $F_{105}I$). In three cultivars (99M06, 99M116, and Simheukpi), most of amino acid changes were such that the difference between the amino acid sequences of IFS1 and IFS2 was reduced. The expression profiles of three enzymes that convert naringenin to the isoflavone, genistein, chalcone isomerase (CHI), isoflavone synthase (IFS) and flavanone 3-hydroxylase (F3H) were examined. In general, IFS mRNA was more abundant in etiolated seedlings than mature plants whereas the levels of CHI and F3H mRNAs were similar in the two stages. During seed development, IFS was expressed a little later than CHI and F3H but expression of these three genes was barely detectable, if at all, during later seed hardening. In addition, we found that the levels of CHI, F3H, and IFS mRNAs were under circadian control. We also showed that IFS was induced by wounding and by application of methyl jasmonate to etiolated soybean seedlings.

• Plant Resources
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• 제4권3호
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• pp.181-188
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• 2001

We tried to introduce two forsythia genes related in lignan biosynthesis, dirigent protein and pinoresinol/lariciresinol (Ph) reductase, into potatoes for accumulation of lignans in transgenic potatoes. We made binary vectors overexpressing dirigent protein gene and P/L reductase gene driven by a CaMV35S promoter and transformed into potatoes via Agrobacterium mediated transformation. And in order to control the metabolic flux of lignan biosynthesis pathway, we tried to inhibit chalcone synthase genes of potatoes by antisense inhibition technique also. We tried to use PCR screening method for selection of transgenic plants of different vectors. We tried to determine and compare lignan contents from different transgenic potato lines.