• Title/Summary/Keyword: Fen1

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Cellular DNA Repair of Oxidative Deoxyribose Damage by Mammalian Long-Patch Base Excision Repair

  • Sung Jung-Suk;Son Mi-Young
    • Biomedical Science Letters
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    • v.11 no.2
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    • pp.103-108
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    • 2005
  • 2-Deoxyribonolactone (dL) arises as a major DNA damage induced by a variety of agents, involving free radical attack and oxidation of C1'-deoxyribose in DNA. We investigated whether dL lesions can be repaired in mammalian cells and the mechanisms underlying the role of DNA polymerase $\beta$ in processing of dL lesions. Pol $\beta$ appeared to be trapped by dL residues, resulting in stable DNA-protein cross-links. However, repair DNA synthesis at site-specific dL sites occurred effectively in cell-free extracts, but predominantly accompanied by long-patch base excision repair (BER) pathway. Reconstitution of long-patch BER demonstrated that FEN1 was capable of removing the displaced flap DNA containing a 5'-dL residue. Cellular repair of dL lesions was largely dependent on the DNA polymerase activity of Pol $\beta$. Our observations reveal repair mechanisms of dL and define how mammalian cells prevent cytotoxic effects of oxidative DNA lesions that may threaten the genetic integrity of DNA.

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Design and evaluations of Tonpilz Transducers with self noise suppressing structures (저소음 Tonpilz 트랜스듀서의 설계방안 연구)

  • 임종인
    • Proceedings of the Acoustical Society of Korea Conference
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    • 1996.06a
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    • pp.1-3
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    • 1996
  • 수중 트랜스듀서는 진동하는 물체위에 설치되어 다양한 외부 소음원이 유입되는 환경에 노출되어 있다. 외부 소음원으로는 선체 진동. 프로펠러 소음, 그리고 유동 유기 소음들을 들 수 있고, 트랜스듀서의 실제 작동시 이들의 레벨이 상당히 높아서 센서의 정확한 작동에 장애가 되고 있다. 본 논문에서는 외부 소음원에 무관한 고 정밀, 저 소음 특성을 지닌 음향센서를 개발하기 위하여 유한요소법 (FEN)을 사용하여 소음 전달 특성을 분석하고, air pocket과 음향 감쇠층의 다양한 조합으로 이루어진 구조를 개선한 음향센서의 설계 및 내소음성 평가를 하였다. 또한 사용한 음향 감쇠층의 최적 물성을 제시하고자 한다. 그 결과 센서 측면 하단부에 소음원이 위치할 경우 가장 큰 잡음 신호로 작용하며, 구조를 변경한 결과 기존 음향센서에 비해 55% 이상 내 소음성을 증진 시켰다. 그리고 음향 감쇠층의 최적 음향 임피던슨는 1 Mrayl 이하 혹은 4mrayl 이상으로 분석되었다.

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Identification and Molecular Characterization of Three Isoforms of Iturin Produced by Endophytic Bacillus sp. CY22 (식물 내생균 Bacillus sp. CY22가 생성하는 iturin isoform의 분리 및 특성)

  • Cho, Soo-Jeong;Yun-Han-Dae
    • Journal of Life Science
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    • v.15 no.6 s.73
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    • pp.1005-1012
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    • 2005
  • Endophytic Bacillus sp. CY22 was previously isolated from the interior of balloon flower root and showed strong antifungal activity against phytopathogenic fungi such as Rhizoctonia solnni, Fusarium oxysporum, and Phythium ultimum. Many Bacillus strains produce antifungal compound such as iturin, fengycin, and mycosubtilin. We isolated and identified antifungal compound from cell supernatant of the endophytic strain. By the MALDI-TOF mass result, the antifungal compound was similar to the known antifungal lipopeptide iturin. It was found that the purified iturin had three isoforms with protonated masses of m/z 1,043.39, 1,057.42, and 1,071.42 and different structures in combination with $Na^{+}$ ion using MALDI-TOF MS. The ita22 gene, which transacylase gene is associated with production of antifungal iturin, had an open reading frame (ORF) of 1,200 bp encoding 400 amino acids. Results of deduced amino acids sequence homology search, Ita22 was homologous with FenF (BAB69697) of Bacillus subtilis 168.

Molecular Characterization and Expression Patterns of Porcine Eukaryotic Elongation Factor 1 A

  • Wang, H.L.;Wang, H.;Zhu, Z.M.;Yang, S.L.;Fen, S.T.;Li, Kui
    • Asian-Australasian Journal of Animal Sciences
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    • v.19 no.7
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    • pp.953-957
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    • 2006
  • The eukaryotic elongation factor 1 A (EEF1A) participates in protein synthesis by forming the eEF1A GTP tRNA complex to deliver aminoacyl-tRNA to the A site of ribosomes. This study described cDNA sequences and partial genomic structure of porcine EEF1A1. The porcine EEF1A1 gene encoded a protein with 462 amino acids, which shared complete homology with human, chimpanzee and dog. The temporal expression pattern showed the diversity of EEF1A1 level in mRNA was relatively minor in prenatal embryo skeletal muscle, however, the expression decreased during aging after birth in skeletal muscle of the Chinese Tongcheng pig. The spatial expression patterns indicated that the gene expressed in skeletal muscle, heart, lung, liver, kidney, fat and spleen. In addition, we assigned the gene to porcine chromosome 1 using a radiation hybrid panel.

OsAREB1, an ABRE-binding protein responding to ABA and glucose, has multiple functions in Arabidopsis

  • Jin, Xiao-Fen;Xiong, Ai-Sheng;Peng, Ri-He;Liu, Jin-Ge;Gao, Feng;Chen, Jian-Min;Yao, Quan-Hong
    • BMB Reports
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    • v.43 no.1
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    • pp.34-39
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    • 2010
  • Expression patterns of OsAREB1 revealed that expression of OsAREB1 gene can be induced by ABA, PEG and heat. Yeast one-hybrid assay demonstrated it can bind to ABA-responsive element (ABRE), which was found in most stress-induced genes. Transgenic Arabidopsis over-expressing OsAREB1 had different responses to ABA and glucose compared to wild-type plants, which suggest OsAREB1 might have a crucial role in these two signaling pathways. Further analysis indicate that OsAREB1 have multiple functions in Arabidopsis. First, OsAREB1 transgenic plants had higher resistance to drought and heat, and OsAREB1 up-regulated the ABA/stress related gene such as RD29A and RD29B. Second, it delayed plant flowering time by down-regulating the expression of flowering-related genes, such as FT, SOC1, LFY and AP1. Due to the dates, OsAREB1 may function as a positive regulator in drought/heat stresses response, but a negative regulator in flowering time in Arabidopsis.

Determination of Chromium(VI) and Copper(II) in Organic Solvent - Solution by Liquid Core Optical Fiber Spectrophotometry

  • Wang, JuFang;Fen, Minzhao;Wei, Wang;He, Qushe;Wu, Guanyan
    • Analytical Science and Technology
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    • v.8 no.4
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    • pp.457-460
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    • 1995
  • A new hollow fiber filled with the lower refractive index liquid as core constructs a liquid core optical fiber(LCOF). The LCOF have been used as colorimetric cell to determine elements Cr and Cu in the presence of 70%- 50% ethanol or 50% dioxane aqueous solution, based on colored complex of Chromium(VI) with Diphenycarbazid(DPC) and copper with Chromaurd S(CAS) respectively. The sensitivity (1/ng/ml) of calibration curve of Cr and Cu are 0.052, 0.017 over the range 0 - 25, 0 - 24(ng/ml) respectively. The Cr in the animal gum and Nation Standard of China are determined with recoveries of 94 - 102%.

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RPA-governed Endonuclease Switching during Eukaryotic Okazaki Fragment Processing.

  • Bae, Sung-Ho;Bae, Kwang-Hee;Kim, Jung-Ae;Seo, Yeon-Soo
    • Proceedings of the Korean Biophysical Society Conference
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    • 2001.06a
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    • pp.22-22
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    • 2001
  • At the eukaryotic replication fork, discontinuous synthesis of lagging strand DNA gives rise to Okazaki fragments carrying ribonucleotides derived from the primer RNA at their 5' ends. Efficient removal of these ribonucleotides is vital for maintaining genome integrity. In this report we show that the endonucleases Dna2 and Fen1 act sequentially to facilitate the complete removal of the primer RNA.(omitted)

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Glutathione S-transferase P1 and DNA Polymorphisms with the Response to Chemotherapy and the Prognosis of Bone Tumor

  • Yang, Li-Min;Li, Xiu-Hua;Bao, Cui-Fen
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.11
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    • pp.5883-5886
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    • 2012
  • Osteosarcoma is the most common primary bone malignancy in children and adolescents, and its clinical outcome is poor. We evaluated the response of GSTP1, ERCC1 and ERCC2 to chemotherapy among osteosarcoma patients, and the role of these genes on the prognosis of osteosarcoma. 187 patients with osteosarcoma were administered with methotrexate, cisplatin/adriamycin, actinomycin D, cyclophosphamide, or vincristine treatment. GSTP1, ERCC1 and ERCC2 polymorphism was genotyped by PCR-RFLP assay. The results showed the average survival time of 187 patients were 38.4 months. 97 patients showed response to neoadjuvant chemotherapy. The GSTP1 Val and ERCC2 A/A genotypes had significantly higher rates of response to chemotherapy, with adjusted OR (95% CI) of 2.19 (1.15-6.21) and 2.88 (1.14-13.25). Individuals with ERCC2 A/A genotype were likely to have a lower risk of death from oseosarcoma, and the adjusted HR was 0.32 (0.13-0.95). Our study indicated test of GSTP1 and ERCC2 Lys751Gln polymorphisms might be a candidate pharmacogenomic factors to be explored in the future to identify the osteosarcoma patients who might benefit from chemotherapy.

An Analysis of the 1/f Noise Characteristics of Pocket Implanted MOSFETS (포켓 이온 주입된 MOSFET소자의 1/f 잡음 특성)

  • 이병헌;이기영
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.41 no.3
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    • pp.1-8
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    • 2004
  • The anomalous behavior of the 1/f noise of halo or pocket ion implanted MOSFETs is investigated. The model for the anomalous 1/f noise behaviors of MOSFETs, which consist of inhomogeneous conductance along the channel is improved within a regional approximation as previous works and presented in a fen directly applicable to halo MOSFETs. The presented model reduces to the previous results, discussed in the linear region operation, for small drain bias. Comparisons with experimental results show that the 1/f model based on the regional approach can be applicable for limited ranges, especially for sufficiently large gate bias voltages.