Figure 2.

Cell specificity of the miR-375 promoter. (a) Representation of the location of conserved sequence blocks in the miR-375 gene and derived reporter gene constructs. (b) Promoter region of miR-375 (construct 375b) was ligated upstream to the firefly luciferase reporter gene in the promoter-less vector pGL3-basic. The plasmid was compared with luciferase reporter gene plasmids containing the cell-specific insulin gene promoter and the constitutive TK promoter. Promoter activity of each construct was determined following transfection into the alpha cell line αTC1, beta cell line MIN6, and non-pancreatic cell line NIH-3T3. Firefly luciferase activity was measured and normalized for transfection efficiency according to the activity of a cotransfected Renilla luciferase plasmid. Values are expressed relative to the activity of promoter-less vector pGL3-basic. Each data point represents mean ± SEM (n ≥ 3).