Characterization of GluR6 promoter 2. A. Five constructs of promoter 2 with different extents of deletions at the 5′ end were made in pGL3 by amplifying human normal fibroblast DNA using sense primers F16, F17, F18, F19, F20 in combination with R11. Construct #6, an empty vector, was used as a control. B. Transcriptional activity of different constructs of promoter 2 cloned in pGL3 and designated as 1–6 was determined by cotransfecting each construct with pRL-CMV (pCMV-derived renilla luciferase with enhancer elements) as an internal control. Relative luciferase activity (RLA) is presented as mean of percent of ratio of firefly to renilla luciferase activity obtained in three independent experiments. Fold increase in RLA over the empty vector was calculated for each construct.