Figure 6.

The 5′ 50 nt of the APP 5′-leader are sufficient to internally initiate translation. The APP 5′-leader was divided into three nonoverlapping regions (see schematic) consisting of the 5′ 50 nt (APPa), the internal 44 nt containing the IRE (APPb) and the 3′ 53 nt (APPc). The three APP segments along with the full-length APP 5′-leader and β-globin 5′-leader were inserted into the intercistronic region of the dicistronic luciferase mRNA and transfected into C6 cells. The P:R ratio is normalized to the activity obtained from the mRNA containing the β-globin 5′-leader.