Characterization of the 5'-flanking region of the rat TIS11 gene.

To understand the mechanism underlying the transcriptional regulation of the immediate early gene TIS11, we characterized the 5'-flanking region of the rat TIS11 gene. When fused to the luciferase reporter gene, the 5.3-kb 5'-flanking region of the rat TIS11 gene exhibited functional promoter activity in pheochromocytoma PC12 and hepatoma H4IIE cells. 5'-Deletion analyses indicated that multiple negative and positive regulatory regions were present in the 5'-flanking region, and that some of these regions functioned in a cell type-specific manner. Promoter activity of the rat TIS 11 gene was enhanced by phorbol 12-myristate 13-acetate (PMA) in both cell lines, and the PMA-responsiveness resided within the 5'-flanking region. The induction of promoter activity by PMA was completely blocked by GF109203X or PD98059, inhibitors of protein kinase C and mitogen-activated protein (MAP) kinase kinase, respectively. These results suggested that induction of the rat TIS 11 promoter by PMA is mediated by activation of the protein kinase C/MAP kinase cascade.