• Title/Summary/Keyword: Molecular genetics

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Substantial Evidences Indicate That Inorganic Arsenic Is a Genotoxic Carcinogen: a Review

  • Roy, Jinia Sinha;Chatterjee, Debmita;Das, Nandana;Giri, Ashok K.
    • Toxicological Research
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    • v.34 no.4
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    • pp.311-324
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    • 2018
  • Arsenic is one of the most toxic environmental toxicants. More than 150 million people worldwide are exposed to arsenic through ground water contamination. It is an exclusive human carcinogen. Although the hallmarks of arsenic toxicity are skin lesions and skin cancers, arsenic can also induce cancers in the lung, liver, kidney, urinary bladder, and other internal organs. Arsenic is a non-mutagenic compound but can induce significant cytogenetic damage as measured by chromosomal aberrations, sister chromatid exchanges, and micronuclei formation in human systems. These genotoxic end points are extensively used to predict genotoxic potentials of different environmental chemicals, drugs, pesticides, and insecticides. These cytogenetic end points are also used for evaluating cancer risk. Here, by critically reviewing and analyzing the existing literature, we conclude that inorganic arsenic is a genotoxic carcinogen.

Identification of Hemimethylcted DNA Binding Activity in the seqA Mutant

  • Lee, Ho;Kang, Suk-Hyun;Yim, Jeong-Bin;Hwang, Deog-Su
    • Animal cells and systems
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    • v.2 no.3
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    • pp.351-353
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    • 1998
  • A 245 bp segment of E. coli chromosomal replication origin, oriC, contains 11 repeats of the GATC sequence in which adenine is methylated by Dam methylase. Newly replicated oriC is hemimethylated. The parental strand of the newly replicated oriC is methylated, but the nascent strand is not yet methylated until methylated by Dam methylase. The hemimethylated oriC plays an important role in the regulation of chromosomal replication. Activity in the seqA mutant was identified to bind preferentially to hemimethylated DNA, but not to fully-methylated DNA. This activity may participate in the sequestration of initiation of chromosomal replication.

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Tobacco mitochondrial small heat shock protein NtHSP24.6 adopts a dimeric configuration and has a broad range of substrates

  • Kim, Keun-Pill;Yu, Ji-Hee;Park, Soo-Min;Koo, Hyun-Jo;Hong, Choo-Bong
    • BMB Reports
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    • v.44 no.12
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    • pp.816-820
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    • 2011
  • There is a broad range of different small heat shock proteins (sHSPs) that have diverse structural and functional characteristics. To better understand the functional role of mitochondrial sHSP, NtHSP24.6 was expressed in Escherichia coli with a hexahistidine tag and purified. The protein was analyzed by non-denaturing PAGE, chemical cross-linking and size exclusion chromatography and the $H_6NtHSP24.6$ protein was found to form a dimer in solution. The in vitro functional analysis of $H_6NtHSP24.6$ using firefly luciferase and citrate synthase demonstrated that this protein displays typical molecular chaperone activity. When cell lysates of E. coli were heated after the addition of $H_6NtHSP24.6$, a broad range of proteins from 10 to 160 kD in size remained in the soluble state. These results suggest that NtHSP24.6 forms a dimer and can function as a molecular chaperone to protect a diverse range of proteins from thermal aggregation.

Parameters Affecting Polymerase Chain Reaction in RAPD Analysis of Pleurotus spp. (느타리버섯속(屬)의 DNA 다형성분석(多型性分析)에 영향(影響)을 미치는 PCR 조건(條件))

  • Kim, Beom-Gi;Jeong, Mi-Jeong;Lee, Chang-Soo;Lee, Hee-Kyung;Yoo, Young-Bok;Ryu, Jin-Chang
    • The Korean Journal of Mycology
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    • v.23 no.3 s.74
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    • pp.202-208
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    • 1995
  • This study describes the effects of several components on PCR amplification used for RAPD. We used different concentrations of reaction components to obtaine discrete and reproducible PCR products from Pleurotus cornucopiae. The optimum concentrations of reaction components were found to be 80 ng of template DNA, 30 pmole of 10-mer primer, $200\;{\mu}M$ dNTP, 2mM $MgCl_2$, 50 mM KCl, 10 mM Tris-HCl(pH 9.0), 0.1% Triton X-100, 1.5 unit of Taq DNA polymerase (promega) in $50\;{\mu}l$ reaction volume. The optimum annealing temperature was $35^{\circ}C$. These results proved to be valuable for characterization of Pleurotus spp.

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