Fig. 1.
Expression by synthetic promoters. a CMV and EF1α promoters mapped relative to their transcription start sites (+1). CAAT and TATA, transcription factor binding sites. b Plasmid vector integrated into recombination (FRT) site in HEK-293 Flp-In genome. PSV40, SV40 promoter; PSYN, synthetic promoter derived from either CMV or EF1α; GFP, green fluorescent protein gene; attB, recombination sites for cloning; HygroR, hygromycin resistance gene (translated at upstream ATG); circle, E. coli plasmid elements (c) GFP fluorescence intensity of HEK-293 cells. d mRNA level versus fluorescence intensity; dashed line represents linear regression (y = 0.932x). Expression was normalized to the wild-type CMV promoter (CMVwt). Values are arithmetic means ± s.d. (n = 3) calculated from geometric means of each sample population