Linked Life Data

12016206

Source:http://linkedlifedata.com/resource/pubmed/id/12016206

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
30
pubmed:dateCreated
2002-7-22
pubmed:abstractText
The promutagenic and genotoxic exocyclic DNA adduct 1,N(2)-ethenoguanine (1,N(2)-epsilonG) is a major product formed in DNA exposed to lipid peroxidation-derived aldehydes in vitro. Here, we report that two structurally unrelated proteins, the Escherichia coli mismatch-specific uracil-DNA glycosylase (MUG) and the human alkylpurine-DNA-N-glycosylase (ANPG), can release 1,N(2)-epsilonG from defined oligonucleotides containing a single modified base. A comparison of the kinetic constants of the reaction indicates that the MUG protein removes the 1,N(2)-epsilonG lesion more efficiently (k(cat)/K(m) = 0.95 x 10(-3) min(-1) nm(-1)) than the ANPG protein (k(cat)/K(m) = 0.1 x 10(-3) min(-1) nm(-1)). Additionally, while the nonconserved, N-terminal 73 amino acids of the ANPG protein are not required for activity on 1,N(6)-ethenoadenine, hypoxanthine, or N-methylpurines, we show that they are essential for 1,N(2)-epsilonG-DNA glycosylase activity. Both the MUG and ANPG proteins preferentially excise 1,N(2)-epsilonG when it is opposite dC; however, unlike MUG, ANPG is unable to excise 1,N(2)-epsilonG when it is opposite dG. Using cell-free extracts from genetically modified E. coli and murine embryonic fibroblasts lacking MUG and mANPG activity, respectively, we show that the incision of the 1,N(2)-epsilonG-containing duplex oligonucleotide has an absolute requirement for MUG or ANPG. Taken together these observations suggest a possible role for these proteins in counteracting the genotoxic effects of 1,N(2)-epsilonG residues in vivo.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
26
pubmed:volume
277
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
26987-93
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
1,N(2)-ethenoguanine, a mutagenic DNA adduct, is a primary substrate of Escherichia coli mismatch-specific uracil-DNA glycosylase and human alkylpurine-DNA-N-glycosylase.
pubmed:affiliation
Groupe Réparation de l'ADN, Unité Mixte de Recherche 8532 CNRS, Laboratoire de Biotechnologies et Pharmacologie Génétique Appliquée-Ecole Normale Supérieure Cachan, Institut Gustave Roussy, 94805 Villejuif Cedex, France. smurat@igr.fr
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't