Linked Life Data

16221681

Source:http://linkedlifedata.com/resource/pubmed/id/16221681

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
49
pubmed:dateCreated
2005-12-5
pubmed:abstractText
The oxidatively induced DNA lesions 2,6-diamino-4-hydroxy-5-formamidopyrimidine (FapyG) and 4,6-diamino-5-formamidopyrimidine (FapyA) are formed abundantly in DNA of cultured cells or tissues exposed to ionizing radiation or to other free radical-generating systems. In vitro studies indicate that these lesions are miscoding, can block the progression of DNA polymerases, and are substrates for base excision repair. However, no study has yet addressed how these lesions are metabolized in cellular extracts. The synthesis of oligonucleotides containing FapyG and FapyA at defined positions was recently reported. These constructs allowed us to investigate the repair of Fapy lesions in nuclear and mitochondrial extracts from wild type and knock-out mice lacking the two major DNA glycosylases for repair of oxidative DNA damage, OGG1 and NTH1. The background level of FapyG/FapyA in DNA from these mice was also determined. Endogenous FapyG levels in liver DNA from wild type mice were significantly higher than 8-hydroxyguanine levels. FapyG and FapyA were efficiently repaired in nuclear and mitochondrial extracts from wild type animals but not in the glycosylase-deficient mice. Our results indicated that OGG1 and NTH1 are the major DNA glycosylases for the removal of FapyG and FapyA, respectively. Tissue-specific analysis suggested that other DNA glycosylases may contribute to FapyA repair when NTH1 is poorly expressed. We identified NEIL1 in liver mitochondria, which could account for the residual incision activity in the absence of OGG1 and NTH1. FapyG and FapyA levels were significantly elevated in DNA from the knock-out mice, underscoring the biological role of OGG1 and NTH1 in the repair of these lesions.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
9
pubmed:volume
280
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
40544-51
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Repair of formamidopyrimidines in DNA involves different glycosylases: role of the OGG1, NTH1, and NEIL1 enzymes.
pubmed:affiliation
Laboratory of Molecular Gerontology, NIA, National Institutes of Health, Baltimore, Maryland 21224, USA.
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural