Reporter assay. A. The reporter constructs are illustrated. pGL3-SOD3 contains the wild type SOD3 enhancer sequence while pGL3-SOD3-mut is identical except for the mutations in the core SOX binding element. These are derived from pGL3-basic shown at the top. B. Normalized relative levels of luciferase activity are shown with the value from pGL3-SOD3 in the absence of wild type siRNA as 100%. The combined amount of wild type and mutant siRNAs was equal in all cases. Data are the average of three independent experiments, and error bars represent standard deviations.