Objective: In this paper, we have introduced topoisomerase inhibitors, mechanism of action and types of them. DNA topoisomerases are ubiquitous enzymes that catalyze essential enzymes to solve the topological problems accompanying key nuclear processes such as DNA replication, transcription, repair and chromatin assembly by introducing temporary single or double strand breaks in the DNA. Result...

The integrity of the genome is essential to the health of the individual and to the reproductive success of a species. Transmission of genetic information is in a selective balance between two opposing forces, the maintenance of genetic stability versus elimination of mutational change and loss of evolutionary potential. Caenorhabditis elegans provides many advantages for the study of DNA surve...

body-is the subject of the next few chapters. The primitive fear response, once a survival mechanism for confronting genuine physical danger, is inappropriate for the relatively innocuous physical challenges we encounter today. The panic reaction, which sets our adrenalin pumping, may be a "protective mechanism gone wrong." Agras also contends that the "old brain," the septo-hippocampal region,...

objective: people are usually susceptible to carcinogenic aromatic amines, present in cigarrette smoke and polluted environment, which can cause dna damage. therefore, maintenance of genomic dna integrity is a direct result of proper function of dna repair enzymes. polymorphic diversity could affect the function of repair enzymes and thus augment the risk of different cancers. xeroderma pigment...

UNLABELLED Repair-FunMap is a functional database of the DNA repair systems. This database contains not only the proteins directly involved in DNA repair, but also the proteins that interact with the DNA repair proteins. A protein interaction network associated with the human DNA repair processes was established according to the functional relationship between proteins in the database. This net...

Cloning of the OGG1 gene from Saccharomyces cerevisiae has revealed that DNA glycosylases are not necessarily conserved throughout phylogeny, yet there is a DNA-repair protein superfamily with a wide substrate specificity found from bacteria to man.

Cellular DNA damage is reversed by balanced repair pathways that avoid accumulation of toxic intermediates. Despite their importance, the organization of DNA repair pathways and the function of repair enzymes in vivo have remained unclear because of the inability to directly observe individual reactions in living cells. Here, we used photoactivation, localization, and tracking in live Escherich...

abstract accumulation of gene changes and chromosomal instability in response to cellular dna damage lead to cancer. dna damage induces cell cycle checkpoints pathways. checkpoints regulate dna replication and cell cycle progression, chromatin restructuring, and apoptosis. checkpoint kinase 2 (chk2) is activated in response to dna lesions. atm phosphorylate chk2. the activated chk2 kinase can p...

In mammals, there is a complex and intriguing relationship between DNA repair and gametogenesis. DNA repair mechanisms are involved not only in the repair of different types of DNA damage in developing germline cells, but also take part in the meiotic recombination process. Furthermore, the DNA repair mechanisms should tolerate mutations occurring during gametogenesis, to a limited extent. In t...

DNA mismatch repair defects in certain cell types confer resistance to the cytotoxic effects of alkylating agents, suggesting that a normally functioning DNA mismatch repair pathway can actually mediate alkylation-induced cell death. In eukaryotic cells this phenomenon is only observed in cells lacking adequate DNA methyltransferase for the repair of 0*-methylguanine (O*MeG) DNA lesions. It has...