• Title/Summary/Keyword: DNA-cleavage

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The 2,3-Dihydroxybiphenyl 1,2-Dioxygenase Gene (phnQ) of Pseudomonas sp. DJ77: Nucleotide Sequence, Enzyme Assay, and Comparison with Isofunctional Dioxygenases

  • Kim, Seong-Jae;Shin, Hee-Jung;Park, Yong-Chjun;Kim, Young-Soo;Min, Kyung-Hee;Kim, Young-Chang
    • BMB Reports
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    • v.32 no.4
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    • pp.399-404
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    • 1999
  • 2,3-Dihydroxybiphenyl 1,2-dioxygenase (2,3-DHBD), which catalyzes the ring meta-cleavage of 2,3-dihydroxybiphenyl, is encoded by the phnQ gene of biphenyl- and phenanthrene-degrading Pseudomonas sp. strain DJ77. We determined the nucleotide sequence of a DNA fragment of 1497 base pairs which included the phnQ gene. The fragment lncluded an open reading frame of 903 base pairs to accommodate the enzyme. The predicted amino acid sequence of the enzyme subunit consisted of 300 residues. In front of the gene, a sequence resembling an E. coli promoter was identified, which led to constitutive expression of the cloned gene in E. coli. The deduced amino acid sequence of the PhnQ enzyme exhibited 85.6% identity with that of the corresponding enzyme in Sphingomonas yanoikuyae Q1 (formerly S. paucimobilis Q1) and 22.1% identity with that of catechol 1,2,3-dioxygenase from the same DJ77 strain. PhnQ showed broader substrate preference than previously-cloned PhnE, catechol 2,3-dioxygenase. Ten amino acid residues, considered to be important for the role of extradiol dioxygenases, were conserved.

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Momordica charantia Protects against Cytokine-induced Apoptosis in Pancreatic $\beta$-Cells

  • Kim, Kyong;Kim, Hye-Young
    • Food Science and Biotechnology
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    • v.17 no.5
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    • pp.947-952
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    • 2008
  • The unripe fruit of Momordica charantia (MC) has been shown to possess antidiabetic activity. However, the mechanism of its antidiabetic action has not been fully understood. In this study, the effects of the aqueous ethanolic extract of MC (AEE-MC) were evaluated on the apoptosis in pancreatic $\beta$-cells treated with a combination of the cytokines, interleukin (IL)-$1{\beta}$, tumor necrosis factor (TNF)-$\alpha$, and interferon (IFN)-$\gamma$. In MIN6N8 cells, the inhibitory effect of AEE-MC was significantly observed at 2 to 50 ${\mu}g/mL$: a 26.2 to 55.6% decrease of cytoplasmic DNA fragments quantified by an immunoassay. The molecular mechanisms, by which AEE-MC inhibited $\beta$-cell apoptosis, appeared to involve the inhibition on the expression of p21, Bax, and Bad, the up-regulation of Bcl-2 and Bcl-$X_L$, and the inhibition on the cleavage of caspase-9, -7, and -3 and poly (ADP-ribose) polymerase. This study suggests that MC may inhibit cytokine-induced apoptosis in $\beta$-cells and, thus, may contribute via this action to the antidiabetic influence in diabetes.

Study of Signaling Pathway on Apoptotic Cell Death Induced by Extract of Ailanthus altissima in Human Jurkat Lymphocytes (저근백피(樗根白皮) 추출물에 의한 급성 림프성 백혈병 Jurkat Lymphocytes의 세포고사 유도 및 신호기전 연구)

  • Lee, Ki Ouk;Kim, Ae Wha;Lim, Kyu Sang;Yun, Young Gab
    • Herbal Formula Science
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    • v.25 no.3
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    • pp.349-362
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    • 2017
  • Objectives : We investigated whether the components of Ailanthus altissima induced apoptotic cell death in Jurkat acute lymphoblastic leukemia (ALL) cells. Methods : Regulation of cell proliferation is a complex process involving the regulated expression and/or modification of discrete gene products, which control transition between different stages of the cell cycle. Results : Upon treatments with Ailanthus altissima, the concentration-dependent inhibitions of cell viability were observed as compared to untreated control group. The capability of Ailanthus altissima to induce apoptosis was associated with proteolytic cleavage of specific target proteins such as poly(ADP-ribose)polymerase (PARP) and beta-catenin proteins suggesting the possible involvement of caspases. Ailanthus altissima also caused apoptosis as measured by cell morphology and DNA fragmentation. Conclusions : These results indicate that the increase of apoptotic cell death by Ailanthus altissima may be due to the inhibition of cell cycle in human Jurkat lymphocytes. Conclusively, these current and further findings will provide novel approaches to understanding and treating major diseases.

Inhibition of Apoptosis is Responsible for the Acquired Resistance of K562 Cells to Cisplatin

  • Lee, Soo-Yong;Kim, Dong-Hyun
    • Biomolecules & Therapeutics
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    • v.12 no.2
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    • pp.85-91
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    • 2004
  • In all attempt to elucidate the role of apoptosis in drug resistance, cisplatin-resistant human chronic myelogenous leukemia (CML) K562 cells (K562/CDDP) were established and compared with drug sensitive parent cells (K562) in the induction of apoptosis. K562/CDDP cells were 5-fold more resistant to cisplatin compared to K562 cells. In addition, K562/CDDP cells were significantly more resistant to apoptois as judged by DNA fragmentation and DAPI staining. K562/CDDP cells exhibited decreased proleolytic activity of caspase-3 and this was further demonstrated by decreased cleavage of its substrate poly (ADP-ribose) polymerase (PARR- Western blot analysis showed that K562/CDDP cells had longer sustained levels of BCL-$X_L$ whereas no difference was noted in the level of Bcl-2. the translocation of Bax to mitochondria was significantly delayed in K562/CDDP cells. These results suggest that the reduced translocation of Bax and the sustained expression of BCL-$X_L$ may cause resistance to apoptosis through prevention of mitochondria release of cytochrome c, which subsequently induces reduction of caspase-3 activity and that this response is partly responsible for the acquired resistance to cisplatin ill K562 cells.

Antioxidant Activity of (8E,13Z,20Z)-Strobilinin/(7E,13Z,20Z)-Felixinin from a Marine Sponge Psammocinia sp.

  • Jiang, Ya-Hong;Ryu, Seung-Hee;Ahn, Eun-Young;You, Song;Lee, Burm-Jong;Jung, Jee-H;Kim, Dong-Kyoo
    • Natural Product Sciences
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    • v.10 no.6
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    • pp.272-276
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    • 2004
  • During the course of our screening for bioactive metabolites from marine sponges, EZZ, the inseparable 1:1 mixture of (8E,13Z,20Z)-strobilinin and (7E,13Z,20Z)-felixinin has been found to deliver significant cytotoxicity against some cancer cell lines. In this study, the antioxidant activity of EZZ was first time evaluated by a series of antioxidant assays. It was found that EZZ was weak in scavenging the stable free radical 1,1-diphenyl-2-picrylhyrazyl (DPPH), but it was comparable to ascorbic acid in scavenging ABTS and superoxide radicals. In addition, EZZ could protect DNA from hydroxyl radical-induced strand cleavage. The findings of the present study suggest that EZZ possess certain antioxidant activity, which might help to prevent occurrence of cancer by alleviating the oxidative stress in cells.

Growth Inhibition and Apoptosis Induction of Gastric Cancer Cells by Copper (II) Glycinate Complex

  • JE CHUL LEE;JEONG, YONG WOOK;KISUNG KIM;JAE YOUNG OH;JONG CHUN PARK;JUNG HWAN BANG;ANG WON CHOI
    • Journal of Microbiology and Biotechnology
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    • v.13 no.3
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    • pp.394-399
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    • 2003
  • The in vitro cytotoxic effects of newly synthesized copper (II) glycinate complex were investigated in two gastric cancer cell lines of SNU484 and SNU638 cells. The complex inhibited the growth and decreased the viability of both gastric cancer cells in a dose-dependent manner. Gastric cancer tells treated with the complex exhibited the features of apoptosis, as demonstrated by fragmentation of chromosomal DNA, activation of caspase-3-like enzyme, and cleavage of poly[ADP-ribose] polymerase (PARP). With the treatment of copper (II) glycinate complex, the active form of caspase-3 was observed in SNU484 cells, but not in SNU638 cells, indicating that an alternative pathway of apoptosis might have been triggered in SNU638 cells. In conclusion, copper (II) glycinate complex induces apoptosis of SNU484 and SNU638 gastric cancer cells, and it is suggested that novel copper (II) glycinate complex is highly active against human gastric cancer cells.

Secretory Production of Recombinant Urokinase Kringle Domain in Pichia pastoris

  • Kim, Hyun-Kyung;Hong, Yong-Kil;Park, Hyo-Eun;Hong, Sung-Hee;Joe, Young-Ae
    • Journal of Microbiology and Biotechnology
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    • v.13 no.4
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    • pp.591-597
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    • 2003
  • Human urokinase kringle domain, sharing homology with angiostatin kringles, has been shown to be an inhibitor of angiogenesis, which can be used for the treatment of cancer, rheumatoid arthritis, psoriasis, and retinopathy. Here, the expression of the kringle domain of urokinase (UK1) as a secreted protein in high levels is reported. UK1 was expressed in the methylotrophic yeast Pichia pastoris GS115 by fusion of the cDNA spanning from Ser47 to Lys135 to the secretion signal sequence of ${\alpha}-factor$ prepro-peptide. In a flask culture, the secreted UK1 reached about 1 g/l level after 120h of methanol induction and was purified to homogeneity by ion-exchange chromatography. Amino-terminal sequencing of the purified UK1 revealed that it was cleaved at the Ste13 signal cleavage site. The molecular mass of UK1 was determined to be 10,297.01 Da. It was also confirmed that the purified UK1 inhibited endothelial cell proliferation stimulated by basic fibroblast growth factor, vascular endothelial growth factor, or epidermal growth factor, in a dose-dependent manner. These results suggest that a P. pastoris sytem can be employed to obtain large amounts of soluble and active UK1.

Water Extract of Samultang Reduces Apoptotic Cell Death by $H_2O_2$-Induced Oxidative Injury in SK-N-MC Cells

  • Lee, Gyoung-Wan;Kim, Min-Sun
    • The Korean Journal of Physiology and Pharmacology
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    • v.13 no.3
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    • pp.139-145
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    • 2009
  • The purpose of this study was to evaluate the effects of the water extract of Samultang (SMT), a Chinese herb, on apoptotic cell death by $H_2O_2$-induced oxidative stress in SK-N-M C cells. A nuclear fragmentation was observed via fluorescence imaging 12 h after exposure to 30 ${\mu}M$ $H_2O_2$ and DNA laddering was detected via agarose electrophoresis gel. In addition, increases in sub-G1 phase and cleavage of the PARP protein were observed. However, treatment with SMT for 2 h prior to $H_2O_2$ exposure significantly reduced apoptotic cell death induced by incubation with 30 ${\mu}M$ $H_2O_2$ in SK-N-MC cells. Pre-incubation with water extract of SMT for 2 h prevented the $H_2O_2$-induced decrease in mitochondrial transmembrane potential. SMT also attenuated the increase in caspase-3 activity and the breakdown of PARP protein caused by $H_2O_2$-induced oxidative stress. These results suggest that the water extract of SMT provides inhibition of apoptotic cell death against oxidative injury in SK-N-MC cells.

Cloning of pcb Genes in Pseudomonas sp.P20 Specifying Degradation of 4-Clorobiphenyl (4-Chlorobiphenyl을 분해하는 Pseudomonas sp. P20의 pcb 유전자군의 클로닝)

  • 남정현;김치경
    • Microbiology and Biotechnology Letters
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    • v.22 no.4
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    • pp.353-359
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    • 1994
  • Pseudomonas sp. P20 was a bacterial isolate which has the ability to degrade 4-chlorobi- phenyl(4CB) to 4-chlorobenzoic acid via the process of meta-cleavage. The recombinant plasmid pCK1 was constructed by insetting the 14-kb EcoRI fragment of the chromosomal DNA containing the 4CB-degrading genes into the vector pBluescript SK(+). Subsequently, E. coli XL1-Blue was transformed with the hybrid plasmid producing the recombinant E. coli CK1. The recombinant cells degraded 4CB and 2,3-dihydroxybiphenyl(2,3-DHBP) by the pcbAB and pcbCD gene products, respectively. The pcbC gene was expressed most abundantly at the late exponential phase in E. coli CK1 as well as in Pseudomonas sp. P20, and the level of the pcbC gene product, 2,3-DHBP dioxygenase, expressed in E. coli CK1 was about two-times higher than in Pseudomonas sp. P20. The activities of 2,3-DHBP dioxygenase on catechol and 3-methylcatechol were about 26 to 31% of its activity on 2,3-DHBP, but the enzyme did not reveal any activities on 4-methylcatechol and 4-chlorocatechol.

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Expression, Purification and NMR studies of SH3YL1 SH3 domain

  • Shrestha, Pravesh;Yun, Ji-Hye;Lee, Weon-Tae
    • Journal of the Korean Magnetic Resonance Society
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    • v.14 no.2
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    • pp.105-116
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    • 2010
  • SH3YL1, a novel protein containing one Src homology 3 domain at the carboxyl terminus was first detected in mouse anagen skin cDNA. This protein had a significant homology with YHRO 16c/Ysc 84, the yeast Src homology 3 domain-containing protein. The sequence identity was remarkable at the carboxyl and amino-terminal Src homology 3 domain, suggesting that the novel protein is a mouse homolog of the yeast protein and thus was termed as SH3YL1. SH3YL1 is composed of two domains, a DUF500 at N-termini and a SH3 domain at C-termini. In our study we cloned the SH3 domain in bacterial expression system in Escherichia coli using pET32a vector with TEV protease cleavage site and purified as a monomer using affinity chromatography. The N-terminal poly-Histidine tag was cleaved with TEV protease and target protein was used for backbone studies. Our study showed that SH3 domain primarily consists of $\beta$-sheet which is in consistence with previous result performed on the truncated SH3 domain of SH3YL1.