TY - JOUR
T1 - Mutagenic potential of DNA-peptide crosslinks mediated by acrolein-derived DNA adducts
AU - Minko, Irina G.
AU - Kozekov, Ivan D.
AU - Kozekova, Albena
AU - Harris, Thomas M.
AU - Rizzo, Carmelo J.
AU - Lloyd, R. Stephen
N1 - Funding Information:
This work was supported by NIH grants CA 106858 (R.S.L.) and ES 05355 (R.S.L and C.J.R.), and Center Grant ES 000267 (C.J.R.).
PY - 2008/1/1
Y1 - 2008/1/1
N2 - Current data suggest that DNA-peptide crosslinks are formed in cellular DNA as likely intermediates in the repair of DNA-protein crosslinks. In addition, a number of naturally occurring peptides are known to efficiently conjugate with DNA, particularly through the formation of Schiff-base complexes at aldehydic DNA adducts and abasic DNA sites. Since the potential role of DNA-peptide crosslinks in promoting mutagenesis is not well elucidated, here we report on the mutagenic properties of Schiff-base-mediated DNA-peptide crosslinks in mammalian cells. Site-specific DNA-peptide crosslinks were generated by covalently trapping a lysine-tryptophan-lysine-lysine peptide to the N6 position of deoxyadenosine (dA) or the N2 position of deoxyguanosine (dG) via the aldehydic forms of acrolein-derived DNA adducts (γ-hydroxypropano-dA or γ-hydroxypropano-dG, respectively). In order to evaluate the potential of DNA-peptide crosslinks to promote mutagenesis, we inserted the modified oligodeoxynucleotides into a single-stranded pMS2 shuttle vector, replicated these vectors in simian kidney (COS-7) cells and tested the progeny DNAs for mutations. Mutagenic analyses revealed that at the site of modification, the γ-hydroxypropano-dA-mediated crosslink induced mutations at only ∼0.4%. In contrast, replication bypass of the γ-hydroxypropano-dG-mediated crosslink resulted in mutations at the site of modification at an overall frequency of ∼8.4%. Among the types of mutations observed, single base substitutions were most common, with a prevalence of G to T transversions. Interestingly, while covalent attachment of lysine-tryptophan-lysine-lysine at γ-hydroxypropano-dG caused an increase in mutation frequencies relative to γ-hydroxypropano-dG, similar modification of γ-hydroxypropano-dA resulted in decreased levels of mutations. Thus, certain DNA-peptide crosslinks can be mutagenic, and their potential to cause mutations depends on the site of peptide attachment. We propose that in order to avoid error-prone replication, proteolytic degradation of proteins covalently attached to DNA and subsequent steps of DNA repair should be tightly coordinated.
AB - Current data suggest that DNA-peptide crosslinks are formed in cellular DNA as likely intermediates in the repair of DNA-protein crosslinks. In addition, a number of naturally occurring peptides are known to efficiently conjugate with DNA, particularly through the formation of Schiff-base complexes at aldehydic DNA adducts and abasic DNA sites. Since the potential role of DNA-peptide crosslinks in promoting mutagenesis is not well elucidated, here we report on the mutagenic properties of Schiff-base-mediated DNA-peptide crosslinks in mammalian cells. Site-specific DNA-peptide crosslinks were generated by covalently trapping a lysine-tryptophan-lysine-lysine peptide to the N6 position of deoxyadenosine (dA) or the N2 position of deoxyguanosine (dG) via the aldehydic forms of acrolein-derived DNA adducts (γ-hydroxypropano-dA or γ-hydroxypropano-dG, respectively). In order to evaluate the potential of DNA-peptide crosslinks to promote mutagenesis, we inserted the modified oligodeoxynucleotides into a single-stranded pMS2 shuttle vector, replicated these vectors in simian kidney (COS-7) cells and tested the progeny DNAs for mutations. Mutagenic analyses revealed that at the site of modification, the γ-hydroxypropano-dA-mediated crosslink induced mutations at only ∼0.4%. In contrast, replication bypass of the γ-hydroxypropano-dG-mediated crosslink resulted in mutations at the site of modification at an overall frequency of ∼8.4%. Among the types of mutations observed, single base substitutions were most common, with a prevalence of G to T transversions. Interestingly, while covalent attachment of lysine-tryptophan-lysine-lysine at γ-hydroxypropano-dG caused an increase in mutation frequencies relative to γ-hydroxypropano-dG, similar modification of γ-hydroxypropano-dA resulted in decreased levels of mutations. Thus, certain DNA-peptide crosslinks can be mutagenic, and their potential to cause mutations depends on the site of peptide attachment. We propose that in order to avoid error-prone replication, proteolytic degradation of proteins covalently attached to DNA and subsequent steps of DNA repair should be tightly coordinated.
KW - Acrolein
KW - DNA-peptide crosslinks
KW - DNA-protein crosslinks
KW - Hydroxypropano DNA adducts
KW - Mutagenesis
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U2 - 10.1016/j.mrfmmm.2007.08.001
DO - 10.1016/j.mrfmmm.2007.08.001
M3 - Article
C2 - 17868748
AN - SCOPUS:37249015575
SN - 0027-5107
VL - 637
SP - 161
EP - 172
JO - Mutation Research - Fundamental and Molecular Mechanisms of Mutagenesis
JF - Mutation Research - Fundamental and Molecular Mechanisms of Mutagenesis
IS - 1-2
ER -