Abstract:
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.