Identification of Transcriptional Regulatory Elements within Ezrin Gene Basal Promoter in HeLa Cells

Objective To identify of the regulatory elements for human ezrin gene basal promoter activity in human cervical carcinoma cell line HeLa, and to elucidate the transcriptional regulatory mechanism of the ezrin gene in HeLa cells. Methods Effect of Sp1 binding site (-75/-69, relative to transcription start site) and AP-1 binding site (-64/-58) on the human ezrin gene basal promoter activity in HeLa cells was performed using site-directed mutagenesis and dual-luciferase reporter assay system. Specific binding activity of nuclear extracts from HeLa cells to the human ezrin gene basal promoter region was detected by electrophoretic mobility shift assay. Results Deletion and replacement either the Sp1 site or the AP-1 site remained approximately 50% ezrin basal promoter activity in HeLa cells, while replacement both the Sp1 and AP-1 sites nearly abolished this activity. Nuclear extracts from HeLa cells could bind to the basal promoter region of human ezrin gene. Conclusion The Sp1 and AP-1 sites are two important cis-elements for the human ezrin basal promoter activity, and some transcription factors possibly bind to the two elements to transactivate ezrin gene in HeLa cells.