Oxidative DNA damage is one of the most common threats to genome stability and DNA repair enzymes provide protection from the effects of oxidized DNA bases. In mammalian cells, base excision repair (BER) mediated by the OGG1 and MYH DNA glycosylases prevents the accumulation of 8-oxoguanine (8-oxoG) in DNA. When steady-state levels of DNA 8-oxoG were measured in myh(-/-) and myh(-/-)/ogg1(-/-) ...

RNF169 flips the repair switch P oulsen et al. describe an enzyme that helps a cell determine which repair method to use on DNA double-strand breaks (DSBs). Unrepaired DSBs can incite genomic chaos, spurring sections of chromosomes to relocate or even vanish. To ensure that doesn’t happen, a cell wraps a molecular bandage around a DSB. Enzymes arrive at the injury and ubiquitylate the surroundi...

background: exposure to ionizing radiation is known to induce oxidative stress followed by damage to critical biomolecules like lipids, proteins and dna through radiolysis of cellular water. since radiation has been widely used as an important tool in therapy of cancer, the detailed investigation regarding the dna damage and repair kinetics would help to predict the radiation sensitivity of cel...

Many fundamental biological processes depend on intricate networks of interactions between proteins and nucleic acids and a quantitative description of these interactions is important for understanding cellular mechanisms governing DNA replication, transcription, or translation. Here we present a versatile method for rapid and quantitative assessment of protein/nucleic acid (NA) interactions. T...

DNA cytosine methylation represents an intrinsic modification signal of the genome that plays important roles in heritable gene silencing, heterochromatin formation and certain transgenerational epigenetic inheritance. In contrast to the process of DNA methylation that is catalyzed by specific classes of methyltransferases, molecular players underlying active DNA demethylation have long been el...

DNA double strand breaks (DSBs) are abrasions caused in both strands of the DNA duplex following exposure to both exogenous and endogenous conditions. Such abrasions have deleterious effect in cells leading to genome rearrangements and cell death. A number of repair systems including homologous recombination (HR) and non-homologous end-joining (NHEJ) have been evolved to minimize the fatal effe...

Double-strand DNA breaks are the most lethal type of DNA damage induced by ionizing radiations. Previously, we reported that double-strand DNA breaks can be enzymatically produced from two DNA damages located on opposite DNA strands 18 or 30 base pairs apart in a cell-free double-strand DNA break formation assay (Vispé, S., and Satoh, M. S. (2000) J. Biol. Chem. 275, 27386-27392). In the assay ...

In spite of its essential role as the carrier of genetic information, DNA is not an inert structure. The genome is susceptible to potentially mutagenic threats of both endogenous and environmental origin. A dramatic threat to the covalent structure of DNA is posed by breaks in the phosphate backbone affecting one or both strands of the Watson–Crick double helix. Ionizing radiation and certain c...