Role of the enhancer and GATA elements in the human and murine promoter activities.

Transcriptional activities were analyzed in HEL, K562, and LIN-175 cell lines as described in Figure 2. (A) The murine −538 and −396 GPIIb promoter constructs, extending from −538 and −396 to +32 respectively, were first analyzed. The human −598/−406 enhancer fragment generated by PCR and sequenced was inserted in direct or reverse orientation upstream from the murine −396 GPIIb promoter fragment. A disrupting mutation was introduced into the murine −456 GATA site of the murine −899 GPIIb promoter construct. Activity of this mutated promoter (−899 mG*) was compared with that of the wild-type (−899 WT) murine promoter. (B) The murine chimeric (−899* hGATA) construct with hGATA region (open box) and the human 813 chimeric (−813* mGATA) construct with mGATA region (gray-filled box) were transfected in HEL, K562, and LIN-175 cells. CAT activities are compared with that of the wild-type murine and human GPIIb promoter constructs as described in Figure 2.