The basis objective of this program is to understand in detail mutational processes, including the mechanisms by which mutagens induce mutations and also the pathways that result in spontaneous mutations. Towards this end we have developed and are continuing to develop systems in E. coli which allow the determination of mutagenic specificity at a high degree of resolution. Because of the presence of carcinogens in the environment, it is of practical importance to understand the manner in which carcinogenic agents cause mutations that can lead to cancer. We are investigating the specificity of mutations induced by ultraviolet light, benzo(a)pyrene, N-acetoxy-2-fluorenylacetamide, aflatoxin B1, 4-nitroquinoline-1-oxide, in addition to other environmental carcinogens. The research plan combines genetics and biochemistry, in that mutations are analyzed with a variety of genetic systems prior to selecting representative mutations to analyze by DNA sequencing. In addition to analyzing lacI nonsense mutations, we are employing selection systems in lacI that are specific for +1 and -1 frameshifts and for deletions. By understanding the specificity of mutagenesis, we hope to be able to pinpoint specific premutational lesions resulting from carcinogens binding to DNA and to elucidate the pathways that lead to mutations. Analysis of repair deficient and mutator strains should help identify pathways involved in generating spontaneous mutations.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM032184-03
Application #
3280786
Study Section
Microbial Physiology and Genetics Subcommittee 2 (MBC)
Project Start
1983-07-01
Project End
1986-06-30
Budget Start
1985-07-01
Budget End
1986-06-30
Support Year
3
Fiscal Year
1985
Total Cost
Indirect Cost
Name
University of California Los Angeles
Department
Type
Schools of Arts and Sciences
DUNS #
119132785
City
Los Angeles
State
CA
Country
United States
Zip Code
90095
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Yang, H; Slupska, M M; Wei, Y F et al. (2000) Cloning and characterization of a new member of the Nudix hydrolases from human and mouse. J Biol Chem 275:8844-53
Miller, J H; Yeung, A; Funchain, P et al. (2000) Temporary and permanent mutators lacking the mismatch repair system: the enhancement of mutators in cell populations. Cold Spring Harb Symp Quant Biol 65:241-52
Miller, J H; Suthar, A; Tai, J et al. (1999) Direct selection for mutators in Escherichia coli. J Bacteriol 181:1576-84
Slupska, M M; Luther, W M; Chiang, J H et al. (1999) Functional expression of hMYH, a human homolog of the Escherichia coli MutY protein. J Bacteriol 181:6210-3
Miller, J H (1998) Mutators in Escherichia coli. Mutat Res 409:99-106
Slupska, M M; King, A G; Lu, L I et al. (1998) Examination of the role of DNA polymerase proofreading in the mutator effect of miscoding tRNAs. J Bacteriol 180:5712-7

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