Figure 5.

The APP 5′-leader can initiate cap-independent translation in vitro. (A) Monocistronic luciferase RNAs containing the 5′-leader from the β-globin and APP mRNAs inserted upstream of the Photinus luciferase ORF were individually translated in micrococcal nuclease-treated RRL in the presence of increasing concentrations of cap analog. The initial level of Photinus luciferase activity from each RNA was normalized to 100. (B) Northern blot analysis was performed on monocistronic RNA isolated from the RRL in vitro translation assays in presence of increasing amounts of cap analog to demonstrate transcript integrity. RNA was probed with DIG-labeled in vitro transcribed probe against Photinus luciferase.