Figure 3. LEF1/TCF cis-elements enhance the expression of PME-1. (A) Schematic diagram of the sequential deletions of the human PME-1 promoter cloned into pGL4.10. Two LEF1/TCF elements are named as LEF1/TCF-1, located at -349 to -333 and labeled in blue color, and LEF1/TCF-2, located at +19 to +35 and labeled in purple color. The deletions shown as panel A left were co-transfected with pRL-TK into HEK-293T cells. The luciferase activity was measured. (B) LEF1/TCF cis-elements 1 and 2 were mutated and the mutated nucleotides are labelled in red color. pGL4/PME-1-1000 with different mutations were co-transfected with pRL-TK into SH-SY5Y cells. The luciferase activity was analyzed. Data are presented as mean ± SD (n=3), *P < 0.05, ***P < 0.001, ****P < 0.0001.