Abstract

The primary focus of this renewal proposal is on how repair enzymes process specific exocyclic DNA adducts, which are formed by diverse environmental mutagens/carcinogens including vinyl compounds, glycidyl ethers, chlorohydroxyfuranones, benzene and therapeutic nitrosoureas such as BCNU or formed by endogenous processes. Unrepaired adducts can block replication or cause mutation since many of these exocyclic adducts are miscoding lesions. The exocyclic adducts to be studied are structurally related but with differing features. Our central hypothesis is that such ring structural features, formed by different carcinogens, will determine specific enzymatic recognition and the type of repair. On this basis, we hope to identify and characterize new repair activities or novel repair enzymes. The proposed approaches from biochemistry and structural studies attempt to define specific structural features or rules that are essential for enzymatic recognition or repair efficiency. In addition, protein-protein interactions in glycosylase excision of exocyclic adducts will be investigated. By using in vitro biochemical approaches and specific oligonucleotides containing a single site-directed adduct, we wish to carry out the following specific aims: (1) To identify DNA glycosylases/endonucleases acting on newly synthesized exocyclic adducts; (2) To examine the initial recognition by mismatch repair (MMR) pathway of the available exocyclic adducts as these lesions form similar structures to mismatches; (3) To explore the potential pathway for p-benzoquinone adduct repair using an in vitro substitution methodology; (4) To study how and to what extent the DNA glycosylases excising exocyclic adducts interact with other cellular proteins such as 5'AP endonucleases, XPG protein and the MMR binding proteins; and (5) Structural studies, such as molecular modeling of damaged DNA/glycosylase complexes, will be performed to aid in understanding how repair enzymes interact with such adducted DNA.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA072079-09
Application #
6861777
Study Section
Chemical Pathology Study Section (CPA)
Program Officer
Okano, Paul
Project Start
1996-09-05
Project End
2008-03-31
Budget Start
2005-04-01
Budget End
2008-03-31
Support Year
9
Fiscal Year
2005
Total Cost
$406,808
Indirect Cost

  Institution

Name
Lawrence Berkeley National Laboratory
Department
Biochemistry
Type
Organized Research Units
DUNS #
078576738
City
Berkeley
State
CA
Country
United States
Zip Code
94720

  Publications

Rodriguez, Ben; Yang, Yanu; Guliaev, Anton B et al. (2010) Benzene-derived N2-(4-hydroxyphenyl)-deoxyguanosine adduct: UvrABC incision and its conformation in DNA. Toxicol Lett 193:26-32
Chenna, Ahmed; Gupta, Ramesh C; Bonala, Radha R et al. (2008) Synthesis of the fully protected phosphoramidite of the benzene-DNA adduct, N2-(4-Hydroxyphenyl)-2'-deoxyguanosine and incorporation of the later into DNA oligomers. Nucleosides Nucleotides Nucleic Acids 27:979-91
Hang, Bo; Guliaev, Anton B (2007) Substrate specificity of human thymine-DNA glycosylase on exocyclic cytosine adducts. Chem Biol Interact 165:230-8
Wang, Ping; Guliaev, Anton B; Elder, Rhoderick H et al. (2006) Alkylpurine-DNA-N-glycosylase excision of 7-(hydroxymethyl)-1,N6-ethenoadenine, a glycidaldehyde-derived DNA adduct. DNA Repair (Amst) 5:23-31
Wang, Ping; Guliaev, Anton B; Hang, Bo (2006) Metal inhibition of human N-methylpurine-DNA glycosylase activity in base excision repair. Toxicol Lett 166:237-47
Xie, Zhongwen; Zhang, Yangbin; Guliaev, Anton B et al. (2005) The p-benzoquinone DNA adducts derived from benzene are highly mutagenic. DNA Repair (Amst) 4:1399-409
Guliaev, Anton B; Singer, B; Hang, Bo (2004) Chloroethylnitrosourea-derived ethano cytosine and adenine adducts are substrates for Escherichia coli glycosylases excising analogous etheno adducts. DNA Repair (Amst) 3:1311-21
Guliaev, Anton B; Hang, Bo; Singer, B (2004) Structural insights by molecular dynamics simulations into specificity of the major human AP endonuclease toward the benzene-derived DNA adduct, pBQ-C. Nucleic Acids Res 32:2844-52
Hang, Bo (2004) Repair of exocyclic DNA adducts: rings of complexity. Bioessays 26:1195-208
Hang, Bo; Singer, B (2003) Protein-protein interactions involving DNA glycosylases. Chem Res Toxicol 16:1181-95

Showing the most recent 10 out of 26 publications