Transcriptional upregulation of DNA polymerase β by TEIF

• Published in: Biochemical and biophysical research communications Vol. 333; no. 3; pp. 908 - 916
• Main Authors: Zhao, Yuanjun, Zheng, Jie, Ling, Yun, Hou, Lin, Zhang, Bo
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 05.08.2005
• Subjects: DNA Polymerase beta - genetics; DNA Polymerase beta - physiology; DNA polymerase β; DNA-Binding Proteins - physiology; HeLa Cells; hTERT; Humans; Immunoprecipitation; Oxidative Stress; Promoter Regions, Genetic; Telomerase; Transcription Factors - physiology; Transcription regulation; Transcription, Genetic - physiology; Up-Regulation - physiology; DNA polymerase β; hTERT; Telomerase; Transcription regulation
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2005.05.172

The overexpression of DNA polymerase β (β-pol) has been identified in lots of human cancers, but the mechanism has seldom been investigated. Telomerase transcriptional element-interacting factor (TEIF) can bind to hTERT promoter, stimulating its transcription and telomerase activities. Here, we report that TEIF could also enhance the expression of β-pol at transcription level. TEIF could specifically activate transcription of β-pol promoter, but not that of DNA polymerase α or δ promoter. The responsible sequences for binding of TEIF were revealed as GC-rich elements dispersing from +19 to −29 nt of β-pol promoter, which due to mutations caused decreasing in binding of TEIF and apparent losing of transactivation activity. The in vivo interaction between TEIF and β-pol promoter was identified by chromatin immunoprecipitation assay. Besides, ectopic expression of TEIF in HeLa cells could upregulate both levels of endogenous β-pol mRNA and protein, and consequently increases resistance to the oxidative stress of H 2O 2. The data may provide new clue to the elucidation of β-pol overexpression in cancers and also a functional link between β-pol and telomerase.