• Title/Summary/Keyword: replication

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Actin-related protein BAF53 is essential for the formation of replication foci

  • Kwon, Su-Jin;Kwon, Hyock-Man
    • Animal cells and systems
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    • v.16 no.3
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    • pp.183-189
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    • 2012
  • It has been suggested that chromatin is organized into the stable structures that provide fundamental units of chromosome architecture in interphase mammalian cells. The stable structures of chromatin can be visualized as replication foci when replicating DNA is labeled with thymidine analogs. Previously, we showed that the chromosome territory expanded after BAF53 knockdown. In this study, we found that BAF53 is required for the formation of replication foci. DNA replication was not impaired in BAF53 knockdown cells, suggesting that the decrease in the number of replication foci is due to disintegration of replication foci, but not suppression of DNA replication. The attractive forces that maintain structural integrity of replication foci could be disrupted by BAF53 knockdown, and it may be responsible, at least in part, for the expansion of chromosome territories after BAF53 knockdown.

PD184352 Releases the Regular Hypoxic Reversible DNA Replication Arrest in T24 Cells

  • Martin, Leenus
    • BMB Reports
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    • v.40 no.6
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    • pp.895-898
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    • 2007
  • The oxygen dependent regulation of DNA replication is an essential property of proliferating mammalian cells. In human T24 bladder cancer cells, several hours of hypoxia leads to reversible DNA replication arrest and re-entry of oxygen induces a burst of replication initiation. This short communication provides strong evidence that PD184352 initiates DNA replication in living hypoxic cells without elevating the oxygen level. PD184352 releases the regular hypoxic replicon arrest, however, at a low intensity compared to the effect of reoxygenation. Moreover, PD184352 shows no effect on normoxically incubated as well as reoxygenated T24 cells.

Inhibitory Effects of Extracts of Paralichtys olivaceus on DNA replication at the Level of Initiation (Paralichthys olivaceous 추출물에 의한 CNA 복제 개시 단계에서의 억제 효과)

  • 이지현;임영해;이수복;김동규;김동선;박남규;정준기;김남득
    • Journal of Life Science
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    • v.11 no.4
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    • pp.371-378
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    • 2001
  • The effects of the RM 60 series on DNA replication systems were examined by using simian virus 40 (SV40) DNA replication system in vitro. The RM 60 series inhibited the DNA replication in the initiation step rather than in the elongation step. Polymerase$\alpha$-primase activity and toposiomerase I activity study were performed subsequently, the RM 60 seies increased the polymerase $\alpha$-primase activity in a low dose, but decreased the activity in a higher dose. The topoisomerase I activity was inhibited by the RM 60 series. This result suggests that the RM 60 series might inhibit some molecules which are required to establish replication forks during the initiation step of the DNA replication.

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SEC Approach for Detecting Node Replication Attacks in Static Wireless Sensor Networks

  • Sujihelen, L.;Jayakumar, C.;Senthilsingh, C.
    • Journal of Electrical Engineering and Technology
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    • v.13 no.6
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    • pp.2447-2455
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    • 2018
  • Security is more important in many sensor applications. The node replication attack is a major issue on sensor networks. The replicated node can capture all node details. Node Replication attacks use its secret cryptographic key to successfully produce the networks with clone nodes and also it creates duplicate nodes to build up various attacks. The replication attacks will affect in routing, more energy consumption, packet loss, misbehavior detection, etc. In this paper, a Secure-Efficient Centralized approach is proposed for detecting a Node Replication Attacks in Wireless Sensor Networks for Static Networks. The proposed system easily detects the replication attacks in an effective manner. In this approach Secure Cluster Election is used to prevent from node replication attack and Secure Efficient Centralized Approach is used to detect if any replicated node present in the network. When comparing with the existing approach the detection ratio, energy consumption performs better.

Hypomethvlation of DNA with 5-Azacvtidine Alters Chromosome Replication Patterns in Cultured Human Lvmphocvtes (배양 인체 백혈구의 chromosome replication에 미치는 DNA hypomethylation의 영향)

  • 원태웅;이석우김우갑
    • The Korean Journal of Zoology
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    • v.37 no.4
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    • pp.437-477
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    • 1994
  • The DNA replication of human Iyrnphocvtes was studied using Bromodeo3fyuridine incorporation. The characteristic patterns of dvnamlc banding were analysed. Human chromosomal ONA was synthesized in a segmental but highly coordinated fashion. Each chromosome replicates according to its innate pattern of chromosome structure (bandinsl. R-positive bands are demonstrated as the initiation sites of DNA synthesis, and G-bnads initiate replication after it has been completed in the autosomal R-bands. Many researchers demonstrated that developmental or induced methvlation of DNA can inactivate the associated gene loci. Such DNA methylation can be reversed and specific genes reactivated by treatment with 5-azacvtidine. We treated the hvpomethvlating agent 5-azacvtidine and tested for changes of DNA replication pattern. Treatment with 5-azacytidine causes an advance in the time of replication. These observed changes in timing of replication suggest that DNA methvlation may modify regional groups of genes in concert.

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Molecular Interactions of a Replication Initiator Protein, RepA, with the Replication Origin of the Enterococcal Plasmid p703/5

  • Cha, Kyung-Il;Lim, Ki-Hong;Jang, Se-Hwan;Lim, Wang-Jin;Kim, Tae-Hyung;Chang, Hyo-Ihl
    • Journal of Microbiology and Biotechnology
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    • v.17 no.11
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    • pp.1841-1847
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    • 2007
  • We previously identified the origin of replication of p703/5, a small cryptic plasmid from the KBL703 strain of Enterococcus faecalis. The origin of replication contains putative regulatory cis-elements required for replication and a replication initiator (RepA) gene. The replicon of p703/5 is similar in its structural organization to theta-type plasmids, and RepA is homologous to a family of Rep proteins identified in several plasmids from Gram-positive bacteria. Here, we report molecular interactions between RepA and the replication origin of p703/5. DNase I footprinting using recombinant RepA together with electrophoretic mobility shift assays confirmed the binding of RepA to the replication origin of p703/5 via iterons and an inverted repeat. We also demonstrated the formation of RepA dimers and the different binding of RepA to the iteron and the inverted repeat using gel filtration chromatographic analysis, a chemical crosslinking assay, and electrophoretic mobility shift assays in the presence of guanidine hydrochloride. Our results suggest that RepA plays a regulatory role in the replication of the enterococcal plasmid p703/5 via mechanisms similar to those of typical iteroncarrying theta-type plasmids.

Exogenous JH and ecdysteroid applications alter initiation of polydnaviral replication in an endoparasitoid wasp, Cotesia plutellae (Braconidae: Hymenoptera)

  • Park, Bok-Ri;Kim, Yong-Gyun
    • BMB Reports
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    • v.44 no.6
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    • pp.393-398
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    • 2011
  • Polydnaviruses are a group of double-stranded DNA viruses and are symbiotically associated with some ichneumonoid wasps. As proviruses, the replication of polydnaviruses occurs in the female reproductive organ at the pupal stage. This study analyzed the effects of two developmental hormones, juvenile hormone (JH) and ecdysteroid, on the viral replication of Cotesia plutellae bracovirus (CpBV). All 23 CpBV segments identified contained a conserved excision/rejoining site ('AGCTTT') from their proviral segments. Using quantitative real-time PCR based on this excision/rejoining site marker, initiation of CpBV replication was determined to have occurred on day 4 on the pupal stage. Pyriproxyfen, a JH agonist, significantly inhibited adult emergence of C. plutellae, whereas RH5992, an ecdysteroid agonist, had no inhibitory effect. Although RH5992 had no effect dose on adult development, it significantly accelerated viral replication. The results of immunoblotting assays against viral coat proteins support the effects of the hormone agonists on viral replication.

Replication of deoxyribonucleic acid (DNA) with respect to gene technology

  • Esser, Karl;Oeser, Birgitt
    • The Microorganisms and Industry
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    • v.12 no.1
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    • pp.28-34
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    • 1986
  • Nucleic acids do not only carry the genetic information, but are also the only substances being able of self-replication. Molecular cloning, an essential tool in biotechnology, requires among other things, an understanding of the mechanisms of replication which at present is fairly well known. After an introduction to the general principle, the status of art on replication procedure and its implication for biotechnology are dealt with.

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An Adaptive Follow-Me Replication Scheme for Service Profile Management in Virtual Home Environment (가상 홈 환경에서 서비스 프로파일 관리를 위한 적응적 추종 중복 기법)

  • 황진경;권순종;박명순
    • Journal of KIISE:Information Networking
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    • v.30 no.4
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    • pp.545-558
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    • 2003
  • It is expected that per-user customized services are widely used in next generation Personal Communication Network. The ultimate goal for personalized service is the Virtual home Environment (VHE) providing ´same-look-and-feel´ services for the subscriber wherever he roams to. To provide personalized services for each call, per-user service profiles are frequently referenced, so efficient service profile management is essentially required. To realized the VHE, typically two schemes, can be employed; One is Intelligent Network based service control and the other is a full replication scheme that always replicates profile in user´s current zone. The first scheme is referred as Central scheme and th second scheme is the modified replication scheme of IMT-2000, we refer to as Follow-Me Replication Unconditional (FMRU). Since the Central scheme only depends on the service cal rate and the FMRU is merely dependent on the movement rate, it is apparent that FMRU scheme outperforms the Central scheme if the call to mobility ratio (CMR) is large, and vice versa. In this paper, we propose a new service profile replication schemes, Adaptive Follow-Me Replication (AFMR) that determine replication automatically according to the user´s CMR. We compared the performance of the AFMR with the non-adaptive Follow-Me Replication unconditional on Demand (FMRUD) scheme. Performance results indicate that as the CMR of a user changes AFMR adapts well compared to the existing schemes.