• 제목/요약/키워드: DNA-cleavage

검색결과 388건 처리시간 0.024초

Characterization of biphenyl biodegradation, and regulation of iphenyl catabolism in alcaligenes xylosoxydans

  • Lee, Na-Ri;On, Hwa-Young;Jeong, Min-Seong;Kim, Chi-Kyung;Park, Yong-Keun;Ka, Jong-Ok;Min, Kyung-Hee
    • Journal of Microbiology
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    • 제35권2호
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    • pp.141-148
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    • 1997
  • Alcaligenes xylosoxydans strain SMN3 capable of utilizing biphenyl grew not only on phenol, and benzoate, but also on salicylate. Catabolisms of biphenyl and salicylate appear to be interrelated since benzoate is a common metabolic intermediate of these compounds. Enzyme levels in the excatechol 2. 3-dioxygenas which is meta-cleavage enzyme of catechol, but did not induce catechol 1, 2-dioxygenase. All the oxidative enzymes of biphenyl and 2, 3,-dihydroxybiphenyl (23DHBP) were induced when the cells were grown on biphenyl and salicylate, respectively. Biphenyl and salicylate could be a good inducer in the oxidation of biphenyl and 2, 3-dihydroxybiphenyl. The two enzymes for the degradation of biphenyl and salicylate were induced after growth on either biphenyl or salicylate, suggesting the presence of a common regulatory element. However, benzoate could not induce the enzymes responsible for the oxidation of these compounds. Biphenyl and salicylate were good inducers for indigo formation due to the activity of biphenyl dioxygenase. These results suggested that indole oxidation is a property of bacterial dioxygenase that form cis-dihydrodiols from aromatic hydrocarbon including biphenyl.

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Pseudolaric Acid B Induces Apoptosis Through p53 and Bax/Bcl-2 Pathways in Human Melanoma A375-S2 Cells

  • Gong Xian-Feng;Wang Min-Wei;Tashiro Shin-Ichi;Onodera Satoshi;Ikejima Takashi
    • Archives of Pharmacal Research
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    • 제28권1호
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    • pp.68-72
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    • 2005
  • Pseudolaric acid B is a major compound found in the bark of Pseudolarix kaempferi Gordon. In our study, pseudolaric acid B inhibited growth of human melanoma cells, A375-S2 in a time and dose-dependent manner. A375-S2 cells treated with pseudolaric acid B showed typical characteristics of apoptosis including morphologic changes, DNA fragmentation, sub-diploid peak in flow cytometry, cleavage of poly-ADP ribose polymerase (PARP) and degradation of inhibitor of caspase-activated DNase (ICAD). P53 protein expression was upregulated while cells were arrested at the $G_2/M$ phase of the cell cycle. There was a decrease in the expression of anti-apoptotic Bcl-2 and Bcl-xL proteins, whereas pro-apoptotic Bax was increased. The two classical caspase substrates, PARP and ICAD, were both decreased in a time-dependent manner, indicating the activation of downstream caspases.

Induction of Intrinsic and Extrinsic Apoptosis Pathways in the Human Leukemic MOLT-4 Cell Line by Terpinen-4-ol

  • Khaw-On, Patompong;Banjerdpongchai, Ratana
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권7호
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    • pp.3073-3076
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    • 2012
  • Terpinen-4-ol is a terpene found in the rhizome of Plai (Zingiber montanum (Koenig) Link ex Dietr.). In this study apoptogenic activity and mechanisms of cell death induced by terpinen-4-ol were investigated in the human leukemic MOLT-4 cell line. Terpinen-4-ol exhibited cytotoxicity in MOLT-4 cells, with characteristic morphological features of apoptosis by Wright's staining. The mode of cell death was confirmed to be apoptosis by flow cytometric analysis after staining with annexin V-FITC and propidium iodide. A sub-G1 peak in DNA histograms of cell cycle assays was observed. Terpinen-4-ol induced-MOLT-4 cell apoptosis mediated through an intrinsic pathway involving the loss of mitochondrial transmembrane potential (MTP) and release of cytochrome c into the cytosol. In addition, terpinen-4-ol also induced apoptosis via an extrinsic pathway by caspase-8 activation resulting in the cleavage of cytosolic Bid. Truncated-Bid (tBid) translocated to mitochondria and activated the mitochondrial pathway in conjunction with down-regulation of Bcl-2 protein expression. Caspase-3 activity also increased. In conclusion, terpinen-4-ol can induce human leukemic MOLT-4 cell apoptosis via both intrinsic and extrinsic pathways.

Characterization and Expression Pattern of Myostatin in the Rockfish, Sebastes schlegeli

  • Lee, Sang-Beum;Kim, Yong-Soo;Jin, Hyung-Joo
    • Fisheries and Aquatic Sciences
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    • 제10권2호
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    • pp.60-67
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    • 2007
  • Myostatin (MSTN; also known as GDF8) is a member of the transforming growth factor ${\beta}-superfamily$ of proteins. MSTN negatively regulates mammalian skeletal muscle growth and development by inhibiting myoblast proliferation. Mice and cattle possessing mutant MSTN alleles display a 'double muscling' phenotype characterized by extreme skeletal muscle hypertrophy and/or hyperplasia. We isolated the full-length cDNA of a novel MSTN gene from S. schlegeli muscle tissue and examined its expression pattern in various tissues. The full-length gene (GenBank DQ423474) consists of 1941bp with an open reading frame of 1134 bp, encoding 377 amino acids that show 62-92% amino acid similarity to other vertebrate MSTNs. The predicted protein contains a conserved proteolytic cleavage site (RXRR) and nine conserved cysteine residues at the C terminus. RT-PCR revealed that the unprocessed and prodomain myostatin mRNAs were predominantly present in muscle, with limited expression in other tissues. However, the mature myostatin mRNA was highly expressed in brain and muscle, intermediately expressed in the gills, intestine, heart, and kidney, and weakly expressed in the liver and spleen.

Depletion of Neuroguidin/CANu1 sensitizes human osteosarcoma U2OS cells to doxorubicin

  • Park, Jin-Hee;Sihn, Choong-Ryoul;Lee, Yeon-Su;Lee, Sung-Jae;Kim, Sang-Hoon
    • BMB Reports
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    • 제44권1호
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    • pp.46-51
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    • 2011
  • Osteosarcoma is a primary bone cancer which occurs mainly in children. Neuroguidin/CANu1 is a nucleolar protein involved in the maintenance of ribosomal structure. In this study, we investigated the effect of Neuroguidin/CANu1 depletion on the response of osteosarcoma cells to doxorubicin. In normal circumstances, Neuroguidin/CANu1 is localized at nucleoli, which translocates to nuclear foci in the presence of doxorubicin. shRNA knockdown of Neuroguidin/CANu1 did not affect cell viability in the absence of doxorubicin, but led to enhanced cytotoxicity in doxorubicin-treated cells. Doxorubicin increased the population of apoptotic cells by 3-fold in Neuroguidin/CANu1-depleted cells compared to that in control cells. Depletion of Neuroguidin/CANu1 mRNA induced the expression of p21 and the cleavage of PARP, leading to increased caspase-3/7 activity. Together, these results suggest that Neuroguidin/CANu1 is required for maintaining cellular homeostasis and may contribute to the improved efficiency of chemotherapy.

Cloning and Sequence Analysis of the xyIL Gene Responsible for 4CBA-Dihydrodiol Dehydrogenase from Pseudomonas sp. S-47

  • 박동우;이상만;가종옥;김지경
    • 미생물학회지
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    • 제38권4호
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    • pp.275-275
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    • 2002
  • Pseudomonas sp. S-47 is capable of catabolizing 4-chlorobenzoate (4CBA) as carbon and energy sources under aerobic conditions via the mesa-cleavage pathway. 4CBA-dioxygenase and 4CBA-dihydrodiol dehydrogenase (4CBA-DD) catalyzed the degradation af 4CBA to produce 4-chlorocatechol in the pathway. In this study, the xylL gene encoding 4CBA-DD was cloned from the chromosomal DNA of Pseudomonas sp. S-47 and its nucleotide sequence was analyzed. The xylL gene was found to be composed of 777 nucleotide pairs and to encode a polypeptide of 28 kDa with 258 amino acid residues. The deduced amino acid sequence of the dehydrogenase (XylL) from strain S-47 exhibited 98% and 60% homologies with these of the corresponding enzymes, Pseudomonas putida mt-2 (XyIL) and Acinetobacter calcoaceticus (BenD), respectively. However, the amino arid sequences show 30% or less homology with those of Pseudomonas putida (BnzE), Pseudomonas putida Fl (TodD), Pseudomonas pseudoalcaligenes KF707 (BphB), and Pseudomonas sp. C18 (NahB). Therefore, the 4CBA-dihydrodiol dehdrogenase of strain S-47 belongs to the group I dehydrogenase involved in the degradation of mono-aryls with a carboxyl group.

Molecular Cloning and Characterization of Catechol 2, 3-Dioxygenase Gene from Aniline-Degrading Psseudomonas acidovorans

  • Lee, Ji-Hyun;Bang, Sung-Ho;Park, Youn-Keun;Lee, Yung-Nok
    • 미생물학회지
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    • 제30권4호
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    • pp.316-321
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    • 1992
  • Catechol 2, 3-dioxygenase (C230) catalyses the oxidative ring cleavage of catechol to 2-hydroxymuconic semialdehyde. This is one of the key reactions in the metabolism of the widespresd pollutant aniline. We have cloned a gene encoding C230 from cells of the aniline degrading bacteria, Pseudomonas acidovorance KCTC2494 strain and expressed in E. coli, A 11.3-kilobase Sau3A partial digested DNA fragment from KCTC2494 was cloned into phagemid vector pBluescript and designated as pLP201. The C230 gene was mapped to a 2.8-kb region, and the derection of transcription was determined. The cloned C230 gene contains its own promoter which can be recognized and employed by E. coli transcriptional apparatus. C230 activities of subclones were identified by enzyme assay and activity staining. The T7 RNA promoter/polymerase system and maxicell analysis showed that a polypeptide with Mw of 35 kDa is the C230 gene product.

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Polyadenylation Is Dispensable for Encapsidation and Reverse Transcription of Hepatitis B viral Pregenomic RNA

  • Lee, Hye-Jin;Lee, Jehan;Shin, Myeong-Kyun;Ryu, Wang-Shick
    • Molecules and Cells
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    • 제25권4호
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    • pp.545-552
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    • 2008
  • A hepadnaviruses replicates its DNA genome via reverse transcription of an RNA template (pregenomic RNA or pgRNA), which has a cap structure at the 5' end and a poly(A) tail at the 3' end. We have previously shown that the 5' cap is indispensable for encapsidation of the pgRNA. A speculative extension of the above finding is that the cap contributes to encapsidation via its interaction with the poly(A) tail, possibly involving eIF4E-eIF4G-PABP interaction. To test this hypothesis, poly(A)-less pgRNAs were generated via cleavage by a cis-acting hepatitis delta virus ribozyme sequence. We found that accumulation of the poly(A)-less pgRNA was markedly diminished, mostly likely due to its reduced stability. Importantly, however, the remaining poly(A)-less pgRNAs were nonetheless encapsidated and reverse transcribed normally when the reduced stability was taken account. Our finding clearly contradicts the notion that the poly(A) tail has any function in encapsidation and viral reverse transcription.

In vitro Growth Inhibition and Apoptotic Effects of Hang-baek-Tang on HL-60 Cells

  • Park Jun-Ho;Ju Sung-Min;Kim Kun-Jung;Jeon Byung-Hoon;Oh Jung-Mi;Lee Chae-Ho;Han Dong-Min;Kim Won-Sin
    • 동의생리병리학회지
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    • 제19권6호
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    • pp.1636-1639
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    • 2005
  • To develop novel anti-leukemic medicine, we have prepared a Korean traditional medicine, named Hang-baek-Tang, which is composed of 8 kinds of anti-leukemic medicinal plants. The water extracts was examined anti-leukemic activity using the human leukemia cell line, HL-60 cells. HL-60 cells showed the growth inhibition and several apoptotic features, including DNA ladders, morphological changes, by treatment of the cells with Hang-Daek-Tang. We have observed that Hang-baek-Tang induced the activation of caspase-3, caspase-8 and caspase-9. Further molecular analysis demonstrated that Hang-baek-Tang induced cleavage of PARP and increase of hypodiploid (Sub-G1) population in flow cytometric analysis. These results indicate that Hang-baek-Tang has been considered to exert anti-leukemic activity through the procaspase-3 activation pathway.

Induction of Apoptosis in Human Oral Epidermoid Carcinoma Cells by Sophoraflavanone G from Sophora flavescens

  • Cha, Jeong-Dan;Jeong, Mi-Ran;Lee, Young-Eun;Lee, Kyung-Yeol
    • Food Science and Biotechnology
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    • 제16권4호
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    • pp.537-542
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    • 2007
  • Sophora flavescens AITON (Leguminosae) is a typical traditional Korean medical herb considered to exhibit antibacterial, anti-inflammatory, and antipyretic effects, and is also used for the treatment of skin and mucosal ulcers, sores, diarrhea, gastrointestinal hemorrhage, arrhythmia, and eczema. In this study, the compound sophoraflavanone G was isolated from the dried roots of S. flavescens by bioassay-guided fractionation. We then investigated the effects of various concentrations of sophoraflavanone G on cell viability and the induction of apoptosis in KB cells after an incubation of 24 hr. The results were determined by the following methods: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-terazolium bromide (MTT) assay, Hoechst-33258 dye staining, flow cytometry (cell cycle), and Western blotting for caspase-3 and poly (ADP-ribose) polymerase (PARP). We found sophoraflavanone G induced the apoptosis of KB cells in a dose-dependent manner that was verified by DNA fragmentation, apoptotic bodies, the sub-G1 ratio, caspase-3 activity, and cleavage of PARP. These results suggest that sophoraflavanone G has potent anti-proliferative effects on human oral epidermoid carcinoma cells, with the induction of apoptosis.