Linked Life Data

19955329

Source:http://linkedlifedata.com/resource/pubmed/id/19955329

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2010-2-22
pubmed:abstractText
Selenium (Se) belongs to nutrients that are essential for human health. Biological activity of this compound, however, mainly depends on its dose, with a potential of Se to induce detrimental effects at high doses. Although mechanisms lying behind detrimental effects of Se are poorly understood yet, they involve DNA damage induction. Consequently, DNA damage response and repair pathways may play a crucial role in cellular response to Se. Using Saccharomyces cerevisiae we showed that sodium selenite (SeL), an inorganic form of Se, can be toxic and mutagenic in this organism due to its ability to induce DNA double-strand breaks (DSBs). Moreover, we reported that a spectrum of mutations induced by this compound in the stationary phase of growth is mainly represented by 1-4 bp deletions. Consequently, we proposed that SeL acts as an oxidizing agent in yeast producing oxidative damage to DNA. As short deletions could be anticipated to arise as a result of action of non-homologous end-joining (NHEJ) and oxidative damage to DNA is primarily coped with base excision repair (BER), a contribution of these two pathways towards survival, DSB induction, mutation frequency and types of mutations following SeL exposure was examined in present study. First, we show that while NHEJ plays no role in repairing toxic DNA lesions induced by SeL, cells with impairment in BER are sensitized towards this compound. Of BER activities examined, those responsible for processing of 3'-blocking DNA termini seem to be the most crucial for manifestation of the toxic effects of SeL in yeast. Second, an impact of NHEJ and BER on DSB induction after SeL exposure turned to be inappreciable, as no increase in DNA double-strand breakage in NHEJ and BER single or NHEJ BER double mutant upon SeL exposure was observed. Finally, we demonstrate that impairment in both these pathways does not importantly change mutation frequency after SeL exposure and that NHEJ is not responsible for generation of short deletions after SeL treatment, as these were comparably induced in the wild-type and NHEJ-defective cells.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1464-3804
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
25
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
155-62
pubmed:meshHeading
pubmed:year
2010
pubmed:articleTitle
Investigations on the role of base excision repair and non-homologous end-joining pathways in sodium selenite-induced toxicity and mutagenicity in Saccharomyces cerevisiae.
pubmed:affiliation
Laboratory of Molecular Genetics, Cancer Research Institute, Vlárska 7, 833 91 Bratislava, Slovak Republic.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't