• 제목/요약/키워드: Thioredoxin reductase

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Effects of Heterologous Expression of Thioredoxin Reductase on the Level of Reactive Oxygen Species in COS-7 Cells

  • Kang, Hyun-Jung;Hong, Sung-Min;Kim, Byung-Chul;Park, Eun-Hee;Ahn, Kisup;Lim, Chang-Jin
    • Molecules and Cells
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    • 제22권1호
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    • pp.113-118
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    • 2006
  • Thioredoxin reductase (TrxR), a component of the redox control system involving thioredoxin (Trx), is implicated in defense against oxidative stress, control of cell growth and proliferation, and regulation of apoptosis. In the present study a stable transfectant was made by introducing the vector pcDNA3.0 harboring the fission yeast TrxR gene into COS-7 African green monkey kidney fibroblast cells. The exogenous TrxR gene led to an increase in TrxR activity of up to 3.2-fold but did not affect glutathione (GSH) content, or glutaredoxin and caspase-3 activities. Levels of reactive oxygen species (ROS), but not those of nitric oxide (NO), were reduced. Conversely, 1-chloro-2,4-dinitrobezene (CDNB), an irreversible inhibitor of mammalian TrxR, enhanced ROS levels in the COS-7 cells. After treatment with hydrogen peroxide, the level of intracellular ROS was lower in the transfectants than in the vector control cells. These results confirm that TrxR is a crucial determinant of the level of cellular ROS during oxidative stress as well as in the normal state.

Yeast Thioredoxin System의 발현, 정제 및 특성조사 (Expression, Purification and Characterization of Yeast Thioredoxin System.)

  • 정진숙;김명희;김강화
    • 한국미생물·생명공학회지
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    • 제26권6호
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    • pp.483-489
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    • 1998
  • 효모의 전체 게놈서열에서 확인된 새로운 티오레독신(Trx3)과 이미 효모에서 티오레독신으로서의 기능이 보고된 Trx1, 2 및 TR을 대장균에 발현시켜 정제후 활성을 비교, 조사하였다. Trx1, 2 및 TR은 대부분 수용성 분획에 발현되었으며, 이로부터 정제한 단백질의 분자량은 보고된 분자량과 일치하였다. Trx3는 수용성 분획과 침전 분획 모두에서 발현되었으며, 수용성 분획으로부터 정제한 Trx3의 분자량은 14 kDa이었고, 침전 분획의 Trx3는 18 kDa였다. 수용성 분획으로부터 정제한 Trx3의 아미노말단의 아미노산 서열은 FQSSYTS로 분석되었으며 이는 보고된 Trx3의 20번에서 26번의 아미노산에 해당하였다. NADPH, 티오레독신 환원효소와 함께 Trx3는 인슐린과 DTNB의 disulfide 결합을 환원시켰다. Trx3는 디티오트레이톨을 포함하는 금속촉매산화계에 의한 효소 불활성화를 억제하는 TPx1의 항산화효과를 증가시켰으며, TPx1의 항산화활성을 증가시키는 Trx3의 활성은 Trx1 또는 2의 10% 수준이었다. 또한 Trx3는 TPx1의 disulfide를 thiol로 환원시켜 TPx가 티오레독신 의존성 과산화물 분해활성을 갖도록 하였다. Western blotting실험 결과, Trx3에 대한 항체는 효모 조추출물과 정제된 Trx1 및 Trx2와는 교차반응 하지 않았다. 그러나, 효모 CDNA 유전자 은행을 template로 한 PCR 실험 에서는 Trx3를 암호화하는 유전자가 증폭되었다.

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Purification and Properties of Escherichia coli-Corynebacterium nephridii Hybrid Thioredoxin

  • Sa, Jae-Hoon;Lee, Hee-Bong;Lim, Chang-Jin
    • BMB Reports
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    • 제29권2호
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    • pp.116-121
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    • 1996
  • In earlier studies, the genes encoding Escherichia coli thioredoxin and Corynebacterium nephridii thioredoxin C-3 were fused via a common restriction site in the nucleotide sequence coding for the active site of the proteins to generate two chimeric thioredoxins, designated E-C3 (N to C-terminal) and C3-E. The hybrid thioredoxins were overexpressed in E. coli from the cloned chimeric thioredoxin genes by a T7 promoter/polymerase system. To investigate the structure-function relationship of thioredoxin, we purified the E-C3 hybrid thioredoxin through ammonium sulfate fractionation, DEAE-cellulose chromatography, and Sephadex G-50 gel filtration. Its purity was examined on SDS-polyacrylamide gel electrophoresis and the molecular weight of the purified E-C3 hybrid thioredoxin was estimated to be 12,000. On native polyacrylamide gels, the purified E-C3 hybrid thioredoxin shows a much lower mobility than E. coli thioredoxin. E-C3 hybrid thioredoxin exhibits a 40-fold lower catalytic efficiency with E. coli thioredoxin reductase than E. coli thioredoxin. It was shown to catalyze the reduction of insulin disulfide by dithiothreitol. The purified E-C3 hybrid thioredoxin was also characterized in other aspects.

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흡연성분 중 Nicotine, Cotinine, Benzopyrene이 인체 기관지 상피세포에서 항산화제의 발현에 미치는 영향 (Effects of Nicotine, Cotinine and Benzopyrene as Smoke Components on the Expression of Antioxidants in Human Bronchial Epithelial Cells)

  • 김용석;이재형;김상헌;김태형;손장원;윤호주;박성수;신동호
    • Tuberculosis and Respiratory Diseases
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    • 제62권3호
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    • pp.197-202
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    • 2007
  • 흡연물질로서 benzopyrene, nicotine 및 cotinine등은 기관지상피세포인 Beas2B에서 CuZnSOD, thioredoxin, glutathione reductase 등의 발현량에 영향을 주며 특히 thioredoxin 및 glutathione reductase의 발현량을 노출 후 30분에서 4시간 경과 시간대에 증가시켰다가 24시간 이후에는 억제하는 특징을 나타내었다. 상기한 흡연물질에 의한 항산화효소의 조절기전에는 전사인자인 NNF-${\kappa}B$가 관여하는 것으로 추정되었다.

Essential Cysteine Residues of Yeast Thioredoxin 2 for an electron donor to Thioredoxin Peroxidases

  • Lee, Song-Mi;Kim, Kang-Hwa;Choi, Won-Ki
    • BMB Reports
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    • 제34권2호
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    • pp.139-143
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    • 2001
  • Thioredoxin (Trx) is a redox protein possessing conserved sequence Cys-Gly-Pro-Cys in ail organisms. Trx acts as an electron donor of many proteins including thioredoxin peroxidase (TPx). Yeast Trx 2 has two redox active cysteine residues at positions 31 and 34. To investigate the redox activity of each cysteine, we generated mutants C31S, C34S, and C31S/C34S using site directed mutagenesis and examined the redox activity of Trx variants as an electron donor for yeast TPx enzymes. None of the three Cysmutated Trx proteins was active as a redox protein in the 5', 5'-dithiobis-(2-dinitrobenzoic acid) reduction under the condition of the presence of NADPH and thioredoxin reductase, and in the thioredoxin dependent peroxidase activity of yeast TPx II. C34S enhanced the glutamine synthetase protection activity of yeast TPx I, even though 100 times more protein was needed to exhibit the same activity to WT. The formation of a mixed disulfide intermediate between Trx and TPx II subunits was analyzed by SDS-PAGE. The mixed dieter form of TPx II was found only for C34S. These results suggest that Cys-31 more effectively acts as an electron donor for TPx enzymes.

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Protective Role of Thioredoxin Peroxidase Against Ionizing Radiation

  • Lee, Su-Min;Kim, Sun-Yee;Park, Jeen-Woo
    • BMB Reports
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    • 제31권6호
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    • pp.572-577
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    • 1998
  • A soluble protein from Saccharomyces cerevisiae provides protection against a thiol-containing oxidation system but not against an oxidation system without thiol. This 25-kDa protein acts as a peroxidase but requires the NADPH-dependent thioredoxin system or a thiol-containing intermediate, and was thus named thioredoxin peroxidase. The protective role of thioredoxin peroxidase against ionizing radiation, which generates reactive oxygen species harmful tocellular function, was investigated in wild-type and mutant yeast strains in which the tsa gene encoding thioredoxin peroxidase was disrupted by homologous recombination. Upon exposure to ionizing radiation, there was a distinct difference between these two strains in regard to viability and the level of protein carbonyl content, which is the indicative marker of oxidative damage to protein. Activities of other antioxidant enzymes, such as catalase, superoxide dismutase, glucose-6-phosphate dehydrogenase, and glutathione reductase were increased at 200-600 Gy of irradiation in wild-type cells. However, the activities of antioxidant enzymes were not significantly changed by ionizing radiation in thioredoxin peroxidase-deficient mutant cells. These results suggest that thioredoxin peroxidase acts as an antioxidant enzyme in cellular defense against ionizing radiation through the removal of reactive oxygen species as well as in the protection of antioxidant enzymes.

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A Cytosolic Thioredoxin Acts as a Molecular Chaperone for Peroxisome Matrix Proteins as Well as Antioxidant in Peroxisome

  • Du, Hui;Kim, Sunghan;Hur, Yoon-Sun;Lee, Myung-Sok;Lee, Suk-Ha;Cheon, Choong-Ill
    • Molecules and Cells
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    • 제38권2호
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    • pp.187-194
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    • 2015
  • Thioredoxin (TRX) is a disulfide reductase present ubiquitously in all taxa and plays an important role as a regulator of cellular redox state. Recently, a redox-independent, chaperone function has also been reported for some thioredoxins. We previously identified nodulin-35, the subunit of soybean uricase, as an interacting target of a cytosolic soybean thioredoxin, GmTRX. Here we report the further characterization of the interaction, which turns out to be independent of the disulfide reductase function and results in the co-localization of GmTRX and nodulin-35 in peroxisomes, suggesting a possible function of GmTRX in peroxisomes. In addition, the chaperone function of GmTRX was demonstrated in in vitro molecular chaperone activity assays including the thermal denaturation assay and malate dehydrogenase aggregation assay. Our results demonstrate that the target of GmTRX is not only confined to the nodulin-35, but many other peroxisomal proteins, including catalase (AtCAT), transthyretin-like protein 1 (AtTTL1), and acyl-coenzyme A oxidase 4 (AtACX4), also interact with the GmTRX. Together with an increased uricase activity of nodulin-35 and reduced ROS accumulation observed in the presence of GmTRX in our results, especially under heat shock and oxidative stress conditions, it appears that GmTRX represents a novel thioredoxin that is co-localized to the peroxisomes, possibly providing functional integrity to peroxisomal proteins.

Transcriptional Analysis and Pap1-Dependence of the Unique Gene Encoding Thioredoxin Reductase from the Fission Yeast

  • Kang Hyun-Jung;Hong Sung-Min;Kim Byung-Chul;Kim Kyunghoon;Park Eun-Hee;Lim Chang-Jin
    • Journal of Microbiology
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    • 제44권1호
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    • pp.35-41
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    • 2006
  • The unique gene encoding thioredoxin reductase (TrxR) was previously cloned and characterized from the fission yeast Schizosaccharomyces pombe, and its expression was induced by oxidative stress. To elucidate tbe regulatory mechanism of the S. pombe TrxR gene, three fusion plasmids were generated using polymerase chain reaction: pYUTR20, pYUTR30, and pYUTR40. Plasmid pYUTR20 has an upstream region of 891 base pairs, pYUTR30 has 499 in this region, and pYUTR40 has an 186 bp upstream region. Negatively acting sequence is located between $-1,526\;\~\;-891bp$ upstream of the gene. The upstream sequence, responsible for the induction of TrxR by menadione (MD), is situated on the $-499\;\~\;-186bp$ region, which is also required for TrxR induction by mercuric chloride. The same region also appeared to be required for Pap1-mediated transcriptional regulation of the TrxR gene, which contains the two plausible Papl binding sites, TTACGAAT and TTACGCGA. Consistently, basal and inducible expression of the TrxR gene was markedly lower in the Pap1-negative TP108-3C cells than in wild-type yeast cells. In summary, up-regulation of the S. pombe TrxR gene is mediated by Pap1 via the transcriptional motif(s) located on the $-499\;\~\;-186bp$ region.

Nutritional Source and Metabolism of an Essential Element Selenium

  • Suzuki, Kazuo T.
    • 대한약학회:학술대회논문집
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    • 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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    • pp.93-95
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    • 2003
  • Selenium is an ultra trace essential element for the normal functioning body because of forming the active center of redox enzymes such as four kinds of glutathione peroxidases (GPx), thioredoxin reductase (TR) and 5'-iodothyronine deiodinase. However, the adequate range between deficient and excessive levels is very narrow. (omitted)

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