• Title/Summary/Keyword: Nuclease

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cis-Diamminedichloroplatinum (II) induces denaturation and conformational changes in pBR322 DNA (cis-Diamminedichloroplatinum(II)에 의한 pBR322 DNA의 변성과 구조 변화)

  • Koo, Ja-Choon;Lim, Chang-Soo;Hahn, Tae-Ryong;Yang, Jai-Myung
    • Applied Biological Chemistry
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    • v.33 no.4
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    • pp.343-348
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    • 1990
  • E. coli LE392, transformed with CDDP-treated pBR322 DNA, was plated on ampicillin containing media. The number of colonies formed on ampicillin containing agar plate was reduced to undetectable level after treat the DNA with 13.3 ${\mu}M$ CDDP. The CDDP-treated pBR322 DNA was susceptible to sing1e strand DNA specific S1 nuclease and it's migration Pattern in agarose gel electrophoresis was changed. These results suggest that CDDP adduction to pBR322 DNA resulted in denaturation of the double helix and changes in it's conformation which ultimately leads In the inactivation of the ampicillin resistant sere.

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Trends in Protein Engineering for Gene Targeting: Homing Endonucleases and Zinc Finger Nucleases (유전자 표적화를 위한 단백질공학 연구동향: Homing Endonucleases and Zinc Finger Nucleases)

  • Cheong, Dea-Eun;Kim, Geun-Joong
    • KSBB Journal
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    • v.25 no.3
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    • pp.215-222
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    • 2010
  • Monogenic diseases are resulted from modifications in a single gene of human cells. Because their treatment with pharmacological medicine have a temporary effect, continuous nursing care and retreatment are required. Gene therapy, gene targeting and induced pluripotent stem cell (iPSC) are considered permanent treatment methods of them. In gene therapy, however, retroviral vectors that have potential toxicity caused by random insertion of harmful virus are used as vehicles for transferring genetic materials. On the other hand, gene targeting could replace and remove the modified gene though homologous recombination (HR) induced by site-specific endonucleases. This short review provides a brief overview on the recently tailored endonucleses with high selectivity for HR.

Effect of Paternal DNA Damage on Paternal DNA Degradation and Early Embryonic Development in Mouse Embryo: Supporting Evidence by GammaH2AX Expression (마우스 수정란에 있어서 부계 DNA 손상이 부계 DNA 퇴화 및 초기 배발달에 미치는 영향)

  • Kim, Chang Jin;Lee, Kyung-Bon
    • Journal of Animal Reproduction and Biotechnology
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    • v.34 no.3
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    • pp.197-204
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    • 2019
  • This study was investigated to test whether the zygote recognized the topoisomerase II beta (TOP2B) mediated DNA fragmentation in epididymal spermatozoa or the nuclease degradation in vas deferens spermatozoa by testing for the presence of gammaH2AX (γH2AX). The γH2AX is phosphorylation of histone protein H2AX on serine 139 occurs at sites flanking DNA double-stranded breaks (DSBs). The presence of γH2AX in the pronuclei of mouse zygotes which were injected with DNA broke epididymal spermatozoa was tested by immunohistochemistry at 5 and 9 h post fertilization, respectively. Paternal pronuclei that arose from epididymal spermatozoa treated with divalent cations did not stain for γH2AX at 5 h. On the other hand, in embryos injected with vas deferences spermatozoa that had been treated with divalent cations, γH2AX was only present in paternal pronuclei, and not the maternal pronuclei at 5 h. Interestingly, both pronuclei stained positively for γH2AX for all treatments and controls at 9 h after sperm injection. In conclusion, the embryos recognize DNA that is damaged by nuclease, but not by TOP2B because H2AX in phosphorylated in paternal pronuclei resulting from spermatozoa treated with fragmented DNA from vas deferens spermatozoa treated with divalent cations, but not from epididymal spermatozoa treated the same way.

Production of Knockout Mice using CRISPR/Cas9 in FVB Strain

  • Bae, Hee Sook;Lee, Soo Jin;Koo, Ok Jae
    • Journal of Embryo Transfer
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    • v.30 no.4
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    • pp.299-303
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    • 2015
  • KO mice provide an excellent tool to determine roles of specific genes in biomedical filed. Traditionally, knockout mice were generated by homologous recombination in embryonic stem cells. Recently, engineered nucleases, such as zinc finger nuclease, transcription activator-like effector nuclease and clustered regularly interspaced short palindromic repeats (CRISPR), were used to produce knockout mice. This new technology is useful because of high efficiency and ability to generate biallelic mutation in founder mice. Until now, most of knockout mice produced using engineered nucleases were C57BL/6 strain. In the present study we used CRISPR-Cas9 system to generate knockout mice in FVB strain. We designed and synthesized single guide RNA (sgRNA) of CRISPR system for targeting gene, Abtb2. Mouse zygote were obtained from superovulated FVB female mice at 8-10 weeks of age. The sgRNA was injected into pronuclear of the mouse zygote with recombinant Cas9 protein. The microinjected zygotes were cultured for an additional day and only cleaved embryos were selected. The selected embryos were surgically transferred to oviduct of surrogate mother and offsprings were obtained. Genomic DNA were isolated from the offsprings and the target sequence was amplified using PCR. In T7E1 assay, 46.7% among the offsprings were founded as mutants. The PCR products were purified and sequences were analyzed. Most of the mutations were founded as deletion of few sequences at the target site, however, not identical among the each offspring. In conclusion, we found that CRISPR system is very efficient to generate knockout mice in FVB strain.

Enhancement of antimicrobial peptide genes expression in Cactus mutated Bombyx mori cells by CRISPR/Cas9

  • Park, Jong Woo;Yu, Jeong Hee;Kim, Seong-Wan;Kweon, Hae Yong;Choi, Kwang-Ho;Kim, Seong-Ryul
    • International Journal of Industrial Entomology and Biomaterials
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    • v.37 no.1
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    • pp.21-28
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    • 2018
  • CRISPR/Cas9 gene editing system is an efficient method to mutation in a sequence specific manner. Here we report the direct transfection of the Cas9 nuclease and gene specific guide RNA can be used in BM-N cell line derived from Bombyx mori ovarian tissue to enfeeble function of endogenous gene in vitro. We have used gene editing system to negative regulation components of major signaling cascade, the Toll pathway, which controls B. mori resistance to microbe infections, such as fungi and gram positive bacteria. We demonstrate that the $I{\kappa}B-like$ protein Cactus may controls the activation of transcription factors such as Rel A and Rel B. The direct transfection of Cas9 nuclease and Cactus-specific guide-RNA complex may be used in BM-N cells to disrupt the function of endogenous genes in vitro. A mutation frequency of 30-40% was observed in the transfected cells, and various mutations caused the target region. Moreover, RT-PCR analysis revealed that Cactus gene was down regulated after these mutations. More importantly, mutation of BmCactus stimulated expression of lysozyme, moricin, and lebocin genes. These results suggest that the CRISPR/Cas9 systems are expected to efficiently induce site-specific mutations and it was possible to produce antimicrobial peptide through the gene editing.

Production of Mutated Porcine Embryos Using Zinc Finger Nucleases and a Reporter-based Cell Enrichment System

  • Koo, Ok Jae;Park, Sol Ji;Lee, Choongil;Kang, Jung Taek;Kim, Sujin;Moon, Joon Ho;Choi, Ji Yei;Kim, Hyojin;Jang, Goo;Kim, Jin-Soo;Kim, Seokjoong;Lee, Byeong-Chun
    • Asian-Australasian Journal of Animal Sciences
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    • v.27 no.3
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    • pp.324-329
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    • 2014
  • To facilitate the construction of genetically-modified pigs, we produced cloned embryos derived from porcine fibroblasts transfected with a pair of engineered zinc finger nuclease (ZFN) plasmids to create targeted mutations and enriched using a reporter plasmid system. The reporter expresses RFP and eGFP simultaneously when ZFN-mediated site-specific mutations occur. Thus, double positive cells ($RFP^+/eGFP^+$) were selected and used for somatic cell nuclear transfer. Two types of reporter based enrichment systems were used in this study; the cloned embryos derived from cells enriched using a magnetic sorting-based system showed better developmental competence than did those derived from cells enriched by flow cytometry. Mutated sequences, such as insertions, deletions, or substitutions, together with the wild-type sequence, were found in the cloned porcine blastocysts. Therefore, genetic mutations can be achieved in cloned porcine embryos reconstructed with ZFN-treated cells that were enriched by a reporter-based system.

NMR Studies on N-terminal Domain of DNA2

  • Jung, Young-Sang;Lee, Kyoung-Hwa;Jung, Jin-Won;Lee, Weontae
    • Journal of the Korean Magnetic Resonance Society
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    • v.4 no.2
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    • pp.74-81
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    • 2000
  • Saccharomyces cerevisiae Dna2 protein has biochemical activities: DNA-dependent ATPase, DNA helicase and DNA nuclease and is essential for cell viability. Especially, Pro$\^$504/ is determined as an important residue in ATPase, helicase, and nuclease activity. We synthesized and determined the three-dimensional solution structure of N-terminal domain comprising residues of Val$\^$501/ -_Phe$\^$508/ (Dna2$\^$pep/) using two-dimensional $^1$H-NMR and dynamical simulated annealing calculations. On the basis of a total of 44 experimental restraints including NOEs, $^3$J$\_$$\alpha$$\beta$/ and $^3$J$\_$$\alpha$$\beta$/ coupling constants, the solution structures of Dna2$\^$epe/ were calculated with the program CNS. The 23 lowest energy structures were selected out of 50 final simulated-annealing structures. The atomic RMSDs of the final 23 structures fur the individual residues were calculated with respect to the average structure. The mean RMSDs for the 23 structures were 0.042 nm for backbone atoms and 0.316 nm for all heavy atoms, respectively. The Ramachandran plot indicates that the $\Phi$, Ψ angles of the 23 final structures are properly distributed in energetically acceptable regions. Solution structure of Dna2$\^$pep/ showed a single unique turn spanning residues of Asn$\^$503/ Val$\^$506/.

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Expression of the Genes Involved in the Synthesis of Riboflavin from Photobacterium species of Bioluminescent Marine Bacteria (해양 발광 박테리아 Photobacterium Species의 Riboflavin 생합성에 관여하는 유전자들의 발현)

  • 이찬용
    • Korean Journal of Microbiology
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    • v.36 no.1
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    • pp.1-7
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    • 2000
  • The genes involved in riboflavin synthesis (ribI, II, III, and IV) were found immediately downstream of luxG in the lux operon from Photobacterium species. The single stranded DNA containing the intergenic region of lux genes and rib genes from Photobacterium phosphoreum was fully protected by P. phosphoreum mRNA from the S1 nuclease mapping assay suggesting that a transcriptional terminator was not present in the region. In addition, the levels of riboflavin synthase activity in P. phosphoreum was increased during the development of bacterial bioluminescence in the same fashion as the luciferase and fatty acid reductase activities. Insertion of the Photobacterium leiognathi DNA extending from luxB to ribII, between a strong lux promoter and a reporter gene (chloramphenicol acetyltransferase, CAT) and transferred by conjugation into P. leiognathi, did not affect expression of reporter gene. Moreover the CAT gene was not expressed in an analogous construct missing the lux promoter indicating that a promoter was not present in this region. Based on the data here, it can be concluded that the lux genes and rib genes in Photobacterium species are under common regulation.

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Measuring and Reducing Off-Target Activities of Programmable Nucleases Including CRISPR-Cas9

  • Koo, Taeyoung;Lee, Jungjoon;Kim, Jin-Soo
    • Molecules and Cells
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    • v.38 no.6
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    • pp.475-481
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    • 2015
  • Programmable nucleases, which include zinc-finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs), and RNA-guided engineered nucleases (RGENs) repurposed from the type II clustered, regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 9 (Cas9) system are now widely used for genome editing in higher eukaryotic cells and whole organisms, revolutionising almost every discipline in biological research, medicine, and biotechnology. All of these nucleases, however, induce off-target mutations at sites homologous in sequence with on-target sites, limiting their utility in many applications including gene or cell therapy. In this review, we compare methods for detecting nuclease off-target mutations. We also review methods for profiling genome-wide off-target effects and discuss how to reduce or avoid off-target mutations.

Traditional uses, phytochemistry and pharmacological profile of Bambusa arudinacea Retz

  • Soni, Vishal;Jha, Arvind Kumar;Dwivedi, Jaya;Soni, Priyanka
    • CELLMED
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    • v.3 no.3
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    • pp.20.1-20.6
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    • 2013
  • Bambusa arundinacea family Graminae, is one of the precious plant resources of the earth. It has played a significant role in human civilization since ancient times. It is tall sized tree growing throughout India, moist parts of India. It also occurs in Sri Lanka, Malaya, Peru and Myanmar. The different parts of this plant contain silica, cholin, betain, cynogenetic glycosides, albuminoids, oxalic acid, reducing sugar, resins, waxes, benzoic acid, arginine, cysteine, histidine, niacin, riboflavin, thiamine, protein, gluteline, contains lysine, methionine, betain, cholin, proteolytic enzyme, nuclease, urease. Various parts of this plant such as leaf, root, shoot and seed possess anti-inflammatory, antiulcer, anti-diabetic, anti-oxidant, anthelmintic, antifertility, antibacterial, insectisidal, antiarthritic, vessele protection etc. This review mainly focuses on the traditional, phytochemical and pharmacological information of Bambusa arundinacea.