Product Description
This digital document is a journal article from DNA Repair, published by Elsevier in 2006. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

Description:
Oxidative damage to DNA seems to be an important factor in developing many human diseases including cancer. It involves base and sugar damage, base-free sites, DNA-protein cross-links and DNA single-strand (SSB) and double-strand (DSB) breaks. Oxidative DSB can be formed in various ways such as their direct induction by the drug or their generation either through attempted and aborted repair of primary DNA lesions or through DNA replication-dependent conversion of SSB. In general, two main pathways are responsible for repairing DSB, homologous recombination (HR) and non-homologous end-joining (NHEJ), with both of them being potential candidates for the repair of oxidative DSB. We have examined relative contribution of HR and NHEJ to cellular response after oxidative stress in Saccharomyces cerevisiae. Therefore, cell survival, mutagenesis and DSB induction and repair in the rad52, yku70 and rad52 yku70 mutants after hydrogen peroxide (H"2O"2), menadione (MD) or bleomycin (BLM) exposure were compared to those obtained for the corresponding wild type. We show that MD exposure does not lead to observable DSB induction in yeast, suggesting that the toxic effects of this agent are mediated by other types of DNA damage. Although H"2O"2 treatment generates some DSB, their yield is relatively low and hence DSB may only partially be responsible for toxicity of H"2O"2, particularly at high doses of the agent. On the other hand, the basis of the BLM toxicity resides primarily in DSB induction. Both HR and NHEJ act on BLM-induced DSB, although their relative participation in the process is not equal. Based on our results we suggest that the complexity and/or the quality of the BLM-induced DSB might represent an obstacle for the NHEJ pathway. ... Read more

Product Description
This volume is produced from digital images created through the University of Michigan University Library's large-scale digitization efforts. The Library seeks to preserve the intellectual content of items in a manner that facilitates and promotes a variety of uses. The digital reformatting process results in an electronic version of the original text that can be both accessed online and used to create new print copies. The Library also understands and values the usefulness of print and makes reprints available to the public whenever possible. This book and hundreds of thousands of others can be found in the HathiTrust, an archive of the digitized collections of many great research libraries. For access to the University of Michigan Library's digital collections, please see http://www.lib.umich.edu and for information about the HathiTrust, please visit http://www.hathitrust.org ... Read more

Product Description
This digital document is an article from World of Microbiology and Immunology, brought to you by Gale®, a part of Cengage Learning, a world leader in e-research and educational publishing for libraries, schools and businesses.The length of the article is 333 words.The article is delivered in HTML format and is available in your Amazon.com Digital Locker immediately after purchase.You can view it with any web browser.Covers the concepts, theories, discoveries, and pioneers in microbiology and immunology, using a mix of traditional academic and topical articles, this title addresses current ethical, legal, and social issues with special emphasis given to biological warfare and terrorism. ... Read more

Product Description
This volume is produced from digital images created through the University of Michigan University Library's large-scale digitization efforts. The Library seeks to preserve the intellectual content of items in a manner that facilitates and promotes a variety of uses. The digital reformatting process results in an electronic version of the original text that can be both accessed online and used to create new print copies. The Library also understands and values the usefulness of print and makes reprints available to the public whenever possible. This book and hundreds of thousands of others can be found in the HathiTrust, an archive of the digitized collections of many great research libraries. For access to the University of Michigan Library's digital collections, please see http://www.lib.umich.edu and for information about the HathiTrust, please visit http://www.hathitrust.org ... Read more

Product Description
This digital document is a journal article from Mut.Res.-Genetic Toxicology and Environmental Mutagenesis, published by Elsevier in . The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

Description:
In order to get an insight into the possible genotoxicity of essential oils (EOs) used in traditional pharmacological applications we tested five different oils extracted from the medicinal plants Origanum compactum, Coriandrum sativum, Artemisia herba alba, Cinnamomum camphora (Ravintsara aromatica) and Helichrysum italicum (Calendula officinalis) for genotoxic effects using the yeast Saccharomyces cerevisiae. Clear cytotoxic effects were observed in the diploid yeast strain D7, with the cells being more sensitive to EOs in exponential than in stationary growth phase. The cytotoxicity decreased in the following order: Origanum compactum>Coriandrum sativum>Artemisia herba alba>Cinnamomum camphora>Helichrysum italicum. In the same order, all EOs, except that derived from Helichrysum italicum, clearly induced cytoplasmic petite mutations indicating damage to mitochondrial DNA. However, no nuclear genetic events such as point mutations or mitotic intragenic or intergenic recombination were induced. The capacity of EOs to induce nuclear DNA damage-responsive genes was tested using suitable Lac-Z fusion strains for RNR3 and RAD51, which are genes involved in DNA metabolism and DNA repair, respectively. At equitoxic doses, all EOs demonstrated significant gene induction, approximately the same as that caused by hydrogen peroxide, but much lower than that caused by methyl methanesulfonate (MMS). EOs affect mitochondrial structure and function and can stimulate the transcriptional expression of DNA damage-responsive genes. The induction of mitochondrial damage by EOs appears to be closely linked to overall cellular cytotoxicity and appears to mask the occurrence of nuclear genetic events. EO-induced cytotoxicity involves oxidative stress, as is evident from the protection observed in the presence of ROS inhibitors such as glutathione, catalase or the iron-chelating agent deferoxamine. ... Read more

Product Description
This digital document is a journal article from DNA Repair, published by Elsevier in 2007. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.

Description:
Various proteins have been found to play roles in both the repair of UV damaged DNA and heterochromatin-mediated silencing in the yeast Saccharomyces cerevisiae. In particular, factors that are involved in the methylation of lysine-79 of histone H3 by Dot1p have been implicated in both processes, suggesting a bipartite function for this modification. We find that a dot1 null mutation and a histone H3 point mutation at lysine-79 cause increased sensitivity to UV radiation, suggesting that lysine-79 methylation is important for efficient repair of UV damage. Epistasis analysis between dot1 and various UV repair genes indicates that lysine-79 methylation plays overlapping roles within the nucleotide excision, post-replication and recombination repair pathways, as well as RAD9-mediated checkpoint function. In contrast, epistasis analysis with the H3 lysine-79 point mutation indicates that the lysine-to-glutamic acid substitution exerts specific effects within the nucleotide excision repair and post-replication repair pathways, suggesting that this allele only disrupts a subset of the functions of lysine-79 methylation. The overall results indicate the existence of distinct and separable roles of histone H3 lysine-79 methylation in the response to UV damage, potentially serving to coordinate the various repair processes. ... Read more

Product Description
Oxidative and nitrosative stress has been linked to cell survival, eukaryotic aging and many disease conditions. In this process, highly reactive thiol groups of cysteines undergo reversible oxidative thiol modifications in response to reactive oxygen and nitrogen species. This makes cysteine-containing proteins the ideal tools to analyze the role of oxidative stress on survival and aging of pro- and eukaryotic cells. Here, recent developments in in vivo thiol trapping technology combined with mass spectrometry are used to identify redox-regulated cysteine-containing proteins in Escherichia coli and Saccharomyces cerevisiae in response to reactive oxygen and nitrogen species. The physiological importance of the identified proteins is then discussed in detail for both organisms. Finally, the redox status of oxidation-sensitive proteins in chronological aging yeast is used as in vivo read-out to evaluate the role of oxidative stress during the eukaryotic aging process. These studies presented here not only deepened our understanding of redox regulation but also showed the importance of oxidative thiol modifications as key posttranslational modification in pro- and eukaryotic cells. ... Read more

Product Description
Webster's bibliographic and event-based timelines are comprehensive in scope, covering virtually all topics, geographic locations and people. They do so from a linguistic point of view, and in the case of this book, the focus is on "Saccharomyces," including when used in literature (e.g. all authors that might have Saccharomyces in their name). As such, this book represents the largest compilation of timeline events associated with Saccharomyces when it is used in proper noun form. Webster's timelines cover bibliographic citations, patented inventions, as well as non-conventional and alternative meanings which capture ambiguities in usage. These furthermore cover all parts of speech (possessive, institutional usage, geographic usage) and contexts, including pop culture, the arts, social sciences (linguistics, history, geography, economics, sociology, political science), business, computer science, literature, law, medicine, psychology, mathematics, chemistry, physics, biology and other physical sciences. This "data dump" results in a comprehensive set of entries for a bibliographic and/or event-based timeline on the proper name Saccharomyces, since editorial decisions to include or exclude events is purely a linguistic process. The resulting entries are used under license or with permission, used under "fair use" conditions, used in agreement with the original authors, or are in the public domain. ... Read more