Search results for "OxyR"
showing 10 items of 216 documents
Restriction analysis of lambda EMBL3 background recombinants: occurrence of lambda phages carrying a head to tail oriented left arm DNA sequence.
1989
Eight representative recombinant background clones of lambda EMBL3 were analysed using KpnI, BamHI, SalI, EcoRI and HindIII digestion. We found that lambda EMBL3 carries its own left arm in the BamHI cloning site. In the way, recombinant molecules were found to be generated which can grow on Escherichia coli strain NM539. In all cases analysed, the left arm DNA was inserted in a head to tail orientation. Seven clones carried a restored BamHI site at the cos site-BamHI site connection. In the region where the inserted left arm and the right arm were ligated, BamHI cloning produces a large palindromic sequence consisting of two polylinkers. This BamHI site was incompletely cleaved in all case…
DNA double-strand breaks trigger apoptosis in p53-deficient fibroblasts
2001
DNA double-strand breaks (DSBs) are induced by ionizing radiation (IR) and various radiomimetic agents directly, or indirectly as a consequence of DNA repair, recombination and replication of damaged DNA. They are ultimately involved in the generation of chromosomal aberrations and were reported to cause genomic instability, gene amplification and reproductive cell death. To address the question of whether DSBs act as a trigger of apoptosis, we induced DSBs by means of restriction enzyme electroporation and compared the effect with IR in mouse fibroblasts that differ in p53 status [wild-type (+/+) versus p53-deficient (-/-) cells]. We show that (i) electroporation of PVU:II is highly effici…
Redox regulation of genome stability by effects on gene expression, epigenetic pathways and DNA damage/repair
2015
Reactive oxygen and nitrogen species (e.g. H2O2, nitric oxide) confer redox regulation of essential cellular signaling pathways such as cell differentiation, proliferation, migration and apoptosis. In addition, classical regulation of gene expression or activity, including gene transcription to RNA followed by translation to the protein level, by transcription factors (e.g. NF-κB, HIF-1α) and mRNA binding proteins (e.g. GAPDH, HuR) is subject to redox regulation. This review will give an update of recent discoveries in this field, and specifically highlight the impact of reactive oxygen and nitrogen species on DNA repair systems that contribute to genomic stability. Emphasis will be placed …
High-resolution genotyping of Campylobacter strains isolated from poultry and humans with amplified fragment length polymorphism fingerprinting.
1999
ABSTRACT For epidemiological studies of Campylobacter infections, molecular typing methods that can differentiate campylobacters at the strain level are needed. In this study we used a recently developed genotyping method, amplified fragment length polymorphism (AFLP), which is based on selective amplification of restriction fragments of chromosomal DNA, for genetic typing of Campylobacter jejuni and Campylobacter coli strains derived from humans and poultry. We developed an automated AFLP fingerprinting method in which restriction endonucleases Hin dIII and Hha I were used in combination with one set of selective PCR primers. This method resulted in evenly distributed band patterns for amp…
Neuronal Cell Nuclear Factor. A Nuclear Receptor Possibly Involved in the Control of Neurogenesis and Neuronal Differentiation
1997
We have cloned from a cDNA library of neuronal derivatives of retinoic-acid-induced embryonic carcinoma cells a nuclear receptor that may be involved in the control of late neurogenesis and early neuronal differentiation. The receptor which is practically identical in sequence with germ cell nuclear factor, has been designated neuronal cell nuclear factor (NCNF). NCNF is exclusively expressed in the neuronal derivatives of PCC7-Mz1 cells, with the expression beginning within hours of exposure to retinoic acid. In the developing mouse brain, NCNF is expressed in the marginal zones of the neuroepithelium which are known to contain young postmitotic neurons. NCNF binds to the DRO sequence ther…
Role for calnexin and N-linked glycosylation in the assembly and secretion of hepatitis B virus middle envelope protein particles.
1998
ABSTRACT Unlike those of the S and the L envelope proteins, the functional role of the related M protein in the life cycle of the hepatitis B virus (HBV) is less understood. We now demonstrate that a single N glycan, specific for M, is required for efficient secretion of M empty envelope particles. Moreover, this glycan mediates specific association of M with the chaperone calnexin. Conversely, the N glycan, common to all three envelope proteins, is involved neither in calnexin binding nor in subviral particle release. As proper folding and trafficking of M need the assistance of the chaperone, the glycan-dependent association of M with calnexin may thus play a crucial role in the assembly …
DNase I sensitivity of the chromatin of the yeast SUC2 gene for invertase.
1986
The DNase I sensitivity of chromatin of the yeast SUC2 gene, which encodes two forms of invertase, has been studied both in the genome and in a multicopy plasmid carrying the gene and its flaking sequences. Whereas little if any difference in the DNase I sensitivity of the flanking regions was found between the repressed and the derepressed states, derepression of the gene was accompanied by a large increase in the sensitivity of the transcribed region. A well-defined DNase I hypersensitive site was found centered at approximately 120 bp downstream from the end of the coding region. This site seems to be flanked in the 3' non-coding region by strictly positioned nucleosomes, and the structu…
Isolation and Characterization of Epidermal DNA and RNA from Guinea Pig Skin
1971
DNA and RNA were isolated from mammalian epidermis in a relatively small scale procedure. The high purity and native state of the DNA isolated is reflected by its molar absorptivity E (P), its thermal hyperchromicity and its hyperchromicity upon DNase treatment and by its sedimentation profile as well as by its profile in a cesium chloride density gradient. The very low content of protein and RNA, as well as the data of DNA determination, indicate that this method permits the isolation of a highly purified product. This is further substantiated by the determination of UV absorption spectra and by analysis of the base composition.The mammalian skin DNA showed the following properties: Mol. w…
Are we sure we know how to measure 8-oxo-7,8-dihydroguanine in DNA from human cells?
2004
The most commonly measured marker of oxidative DNA damage is 8-oxo-7,8-dihydroguanine (8-oxoGua) or its deoxyribonucleoside (8-oxodGuo). Published estimates of the concentration of 8-oxoGua/8-oxodGuo in DNA of normal human cells vary over a range of three orders of magnitude. Analysis by chromatographic methods (GC-MS, HPLC with electrochemical detection (ECD) or HPLC-MS/MS) is beset by the problem of adventitious oxidation of guanine during sample preparation. An alternative approach, based on the use of the DNA repair enzyme formamidopyrimidine DNA N-glycosylase (FPG) to make breaks in the DNA at sites of the oxidised base, gives much lower values. ESCODD, the European Standards Committee…
Closer to nature: an ATP-driven bioinspired catalytic oxidation process
2013
The capability of DNA to acquire enzyme-like properties has led to the emergence of the so-called DNAzyme field; herein, we take a further leap along this nature-inspired road, demonstrating that a template assembled synthetic G-quartet (TASQ) can act as a pre-catalyst for catalytic peroxidase-mimicking oxidation reactions, whatever its nature (guanine or guanosine-based G-quartets), in an ATP-dependent manner, thereby bringing this bioinspired TASQzyme process even closer to nature.