Mutagenicity of C8-Adenine DNA Adduct from the Environmental Carcinogen 6-Nitrochrysene in Escherichia coli and the Role of SOS Response in Mutagenesis

Mutagenicity of C8-Adenine DNA Adduct from the Environmental Carcinogen 6-Nitrochrysene in Escherichia coli and the Role of SOS Response in Mutagenesis

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Document Type

Abstract

Publication Date

10-2-2019

Abstract

DNA is subjected to damage by a variety of exogenous and endogenous chemicals. If these damages are not repaired by DNA repair pathways before DNA replication occurs, these damages can cause mutations. These mutations have the potential to alter a cells life and function, which in some instances, is the initiation phase to the onset of cancer. 6-nitrochrysene (6-NC) is a known carcinogen found in gasoline and exhaust that can be metabolically activated in human cells to cause DNA damage. Cells are equipped with repair pathways that aid in bypassing or repairing damages of the DNA; E. coli responds to DNA damage by inducing the SOS response. The SOS response activates SOS genes that are involved in multiple DNA metabolism processes. The production of translesion synthesis (TLS) polymerases increases with the induction of the SOS Response which aid in bypassing DNA lesions in E. coli. This research studies the importance of the SOS Response in E. coli when the environmental carcinogen 6-NC forms a C8-adenine lesion site in the p53 tumor suppressor gene. Research found that when the SOS response was induced in E. coli, there was an increase in both survivability and number of mutations compared to the wild type cells studied. These results can be attributed to the increased production of low fidelity TLS polymerases with the induction of the SOS Response. Further work will include studying the role of specific TLS polymerases in bypassing the C8-Adenine adduct derived from 6-NC.

Project Mentor

Ashis K. Basu

Funding and Acknowledgements

Funding: REU Program of the National Science Foundation

Mutagenicity of C8-Adenine DNA Adduct from the Environmental Carcinogen 6-Nitrochrysene in Escherichia coli and the Role of SOS Response in Mutagenesis

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