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.

2.50
Hdl Handle:
http://hdl.handle.net/10541/84320
Title:
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.
Authors:
Saparbaev, Murat K; Langouët, Sophie; Privezentzev, Cyril V; Guengerich, F Peter; Cai, Hongliang; Elder, Rhoderick H; Laval, Jacques
Abstract:
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.
Affiliation:
Cancer Research United Kingdom Carcinogenesis Group, Paterson Institute for Cancer Research, Christie Hospital, Manchester, UK. M20 4BX
Citation:
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. 2002, 277 (30):26987-93 J. Biol. Chem.
Journal:
The Journal of Biological Chemistry
Issue Date:
26-Jul-2002
URI:
http://hdl.handle.net/10541/84320
DOI:
10.1074/jbc.M111100200
PubMed ID:
12016206
Type:
Article
Language:
en
ISSN:
0021-9258
Appears in Collections:
All Paterson Institute for Cancer Research

Full metadata record

DC FieldValue Language
dc.contributor.authorSaparbaev, Murat Ken
dc.contributor.authorLangouët, Sophieen
dc.contributor.authorPrivezentzev, Cyril Ven
dc.contributor.authorGuengerich, F Peteren
dc.contributor.authorCai, Hongliangen
dc.contributor.authorElder, Rhoderick Hen
dc.contributor.authorLaval, Jacquesen
dc.date.accessioned2009-10-16T11:12:29Z-
dc.date.available2009-10-16T11:12:29Z-
dc.date.issued2002-07-26-
dc.identifier.citation1,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. 2002, 277 (30):26987-93 J. Biol. Chem.en
dc.identifier.issn0021-9258-
dc.identifier.pmid12016206-
dc.identifier.doi10.1074/jbc.M111100200-
dc.identifier.urihttp://hdl.handle.net/10541/84320-
dc.description.abstractThe 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.en
dc.language.isoenen
dc.subject.meshAnimals-
dc.subject.meshCell-Free System-
dc.subject.meshDNA Adducts-
dc.subject.meshDNA Glycosylases-
dc.subject.meshDNA Repair-
dc.subject.meshEscherichia coli-
dc.subject.meshGuanine-
dc.subject.meshHumans-
dc.subject.meshKinetics-
dc.subject.meshMice-
dc.subject.meshModels, Chemical-
dc.subject.meshN-Glycosyl Hydrolases-
dc.subject.meshOligonucleotides-
dc.subject.meshProtein Binding-
dc.subject.meshSubstrate Specificity-
dc.subject.meshUracil-DNA Glycosidase-
dc.title1,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.en
dc.typeArticleen
dc.contributor.departmentCancer Research United Kingdom Carcinogenesis Group, Paterson Institute for Cancer Research, Christie Hospital, Manchester, UK. M20 4BXen
dc.identifier.journalThe Journal of Biological Chemistryen
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