The exocyclic pyrimidopurinone DNA adduct, M1dG, is the major product of the reaction of DNA with malondialdehyde or base propenals, which are endogenously generated during the oxidation of polyunsaturated fatty acids or the deoxyribose moieties of DNA, respectively. M1dG gives rise to base substitution and frameshift mutations, and its levels in human and rodent DNA correlate with exposure to oxidative stress in some model systems. We have discovered that M1dG in genomic DNA is oxidized by an as yet unknown nuclear enzyme to the stable and distinct DNA adduct, 6-oxo-M1dG. In cells studied to date, oxidation to 6-oxo-M1dG occurs more rapidly than M1dG repair. Unlike M1dG, which can ring-open to the less mutagenic N2-oxopropenyl-dG when placed opposite dC in duplex DNA, 6-oxo-M1dG is predicted to retain its exocyclic ring rendering it more locally disruptive to the DNA double helix and therefore more mutagenic than M1dG. We will test this hypothesis by (1) using NMR spectroscopy to elucidate the structure of duplex oligonucleotides containing 6-oxo-M1dG, (2) determining the mutagenicity of 6-oxo-M1dG during in vitro replication by translesion polymerases and in vivo replication in E. coli, and (3) identifying, purifying, expressing, and characterizing the enzyme responsible for the oxidation of M1dG. Support of the hypothesis that 6-oxo- M1dG is more mutagenic than M1dG will provide the first demonstration of the metabolic activation of an adduct in genomic DNA. This entirely new concept regarding the disposition of DNA damage lays the foundation for important future studies of how the metabolic products of specific DNA adducts lead to mutations and the resulting genomic dysfunction that is the hallmark of cancer.

Public Health Relevance

The DNA adduct, M1dG, is the most common form of damage resulting from the reaction of the endogenous mutagen malondialdehyde with DNA. We have discovered that M1dG in genomic DNA is oxidized to a new stable adduct 6-oxo-M1dG more quickly than it is repaired. We propose to test the hypothesis that formation of 6-oxo-M1dG represents metabolic activation of a DNA adduct to a more mutagenic adduct, a process that may have important implications for understanding how DNA damage contributes to carcinogenesis.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA087819-18
Application #
9388914
Study Section
Special Emphasis Panel (ZRG1)
Program Officer
Okano, Paul
Project Start
2000-06-01
Project End
2020-12-31
Budget Start
2018-01-01
Budget End
2018-12-31
Support Year
18
Fiscal Year
2018
Total Cost
Indirect Cost
Name
Vanderbilt University Medical Center
Department
Biochemistry
Type
Schools of Medicine
DUNS #
965717143
City
Nashville
State
TN
Country
United States
Zip Code
37240
Galligan, James J; Marnett, Lawrence J (2017) Histone Adduction and Its Functional Impact on Epigenetics. Chem Res Toxicol 30:376-387
Camarillo, Jeannie M; Ullery, Jody C; Rose, Kristie L et al. (2017) Electrophilic Modification of PKM2 by 4-Hydroxynonenal and 4-Oxononenal Results in Protein Cross-Linking and Kinase Inhibition. Chem Res Toxicol 30:635-641
Camarillo, Jeannie M; Rose, Kristie L; Galligan, James J et al. (2016) Covalent Modification of CDK2 by 4-Hydroxynonenal as a Mechanism of Inhibition of Cell Cycle Progression. Chem Res Toxicol 29:323-32
Shuck, Sarah C; Rose, Kristie L; Marnett, Lawrence J (2014) Mass spectrometric methods for the analysis of nucleoside-protein cross-links: application to oxopropenyl-deoxyadenosine. Chem Res Toxicol 27:136-46
Singh, Vipender; Fedeles, Bogdan I; Li, Deyu et al. (2014) Mechanism of repair of acrolein- and malondialdehyde-derived exocyclic guanine adducts by the ?-ketoglutarate/Fe(II) dioxygenase AlkB. Chem Res Toxicol 27:1619-31
Maddukuri, Leena; Shuck, Sarah C; Eoff, Robert L et al. (2013) Replication, repair, and translesion polymerase bypass of N?-oxopropenyl-2'-deoxyadenosine. Biochemistry 52:8766-76
Uddin, Md Jashim; Schulte, Michael I; Maddukuri, Leena et al. (2010) Semisynthesis of 6-chloropurine-2'-deoxyriboside 5'-dimethoxytrityl 3'-(2-cyanoethyl-N,N-diisopropylamino)phosphoramidite and its use in the synthesis of fluorescently labeled oligonucleotides. Nucleosides Nucleotides Nucleic Acids 29:831-40
Cline, Susan D; Lodeiro, M Fernanda; Marnett, Lawrence J et al. (2010) Arrest of human mitochondrial RNA polymerase transcription by the biological aldehyde adduct of DNA, M1dG. Nucleic Acids Res 38:7546-57
Knutson, Charles G; Rubinson, Emily H; Akingbade, Dapo et al. (2009) Oxidation and glycolytic cleavage of etheno and propano DNA base adducts. Biochemistry 48:800-9
Wang, Yazhen; Musser, Sarah K; Saleh, Sam et al. (2008) Insertion of dNTPs opposite the 1,N2-propanodeoxyguanosine adduct by Sulfolobus solfataricus P2 DNA polymerase IV. Biochemistry 47:7322-34

Showing the most recent 10 out of 41 publications