Characterization of human DNA polymerase κ promoter in response to benzo[a]pyrene diol epoxide

DNA polymerase κ (Pol κ), a member of Y-family DNA polymerases, can synthesize DNA with moderate fidelity on undamaged DNAs and replicate accurately in vitro thymine glycol, 8-oxo-G and aromatic adducts such as benzo[a]pyrene diol epoxide (BPDE). However, few studies have been done on the transcriptional regulation of Pol κ. In this study, we predicted and cloned the promoter region of the human POLK gene. Through the analysis of deletion constructs of the POLK promoter, we demonstrated that the region −336/−141 contained repressing elements and the region −141/+226 contained positive regulatory elements for transcription of human Pol κ. Furthermore, quantitative RT-PCR showed that human POLK mRNA expression was dysregulated in FL cells treated by BPDE. The transcriptional activities of the POLK promoter regions −336/+437 and +20/+437 were significantly reduced by BPDE treatment, indicating that transcription factors in this two regions, such as HSF1, may regulate the transcription of human POLK gene in response to BPDE.

► Predicted and cloned the 5′ flanking region of human POLK gene. ► The region −336/−141 contains repressing elements and the region −141/+226 contain positive regulatory elements for transcription of human Pol κ. ► Human POLK mRNA expression can be dysregulated in cells exposed to BPDE. ► The transcription factors located in regions −336/+437 and +20/+437 may regulate the transcription of human POLK in response to BPDE.