Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
2003-11-25
pubmed:abstractText
Etheno(epsilon)-adducts such as 1,N(6)-ethenoadenine (epsilon A), 3,N(4)-ethenocytosine (epsilon C), N(2),3-ethenoguanine (N(2),3-epsilon G), and 1,N(2)-ethenoguanine (1,N(2)-epsilon G) are produced in cellular DNA by two independent pathways: (i) by reaction with oxidised metabolites of vinyl chloride, 2-chloroacetaldehyde and 2-chloroethylene oxide; (ii) by endogenous processes through the interaction of lipid peroxidation (LPO)-derived aldehydes and hydroxyalkenals. They have been found in DNA isolated from human and rodent tissues. However, the levels of adducts were significantly increased by cancer risk factors contributing to lipid peroxidation and oxidative stress. The highly mutagenic and genotoxic properties of epsilon-adducts have been established in vitro by analysing steady-state kinetics of primer extension assays and in vivo by site-specific mutagenesis in mammalian cells. Therefore, the repair processes eliminating exocyclic adducts from DNA should play a crucial role in maintaining the stability of genetic information. The epsilon-adducts are eliminated by the base excision repair (BER) pathway, with DNA glycosylases being the key enzymes of this pathway. They remove epsilon-adducts from DNA by hydrolysing the N-glycosidic bond between the damaged base and deoxyribose, leaving an abasic site in DNA. The ethenobase-DNA glycosylases have been identified and their enzymatic properties described. They are specific for a given epsilon-base although they can also excise different types of modified bases, such as alkylated purines, hypoxanthine and uracil. The fact that ethenoadducts are recognised and excised with high efficiency by various DNA glycosylases in vitro suggests that these enzymes may be responsible for repair of these mutagenic lesions in vivo, and thus constitute important contributors to genetic stability.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0027-5107
pubmed:author
pubmed:issnType
Print
pubmed:day
29
pubmed:volume
531
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
219-29
pubmed:dateRevised
2009-11-3
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Enzymology of repair of etheno-adducts.
pubmed:affiliation
Groupe Réparation de l'ADN, UMR8113 CNRS, LBPA-ENS Cachan, Institut Gustave Roussy, 39 rue Camille Desmoulins, 94805 Villejuif Cedex, France.
pubmed:publicationType
Journal Article, Review, Research Support, Non-U.S. Gov't