FIGURE 9.

40S and 60S ribosomal subunits enhance translation in upf1Δ extracts. Cell-free translation extracts were prepared from WT or upf1Δ cells. (A) Extracts were supplemented with 100 ng of CAN1/LUC mRNA and then incubated with BSA (white boxes), purified 40S subunits (black boxes), or purified 60S subunits (gray boxes) for 60 min at 18°C. Luciferase activity is depicted relative to the value obtained with the BSA control for each extract. The graph depicts the average of two experiments. (B) Western blot of increasing amounts of purified 40S (5, 10, and 15 μg) and 60S (5, 10, and 15 μg) subunit preparations probed with polyclonal anti-Upf1 antibody. WT and upf1Δ extracts (5 μg each) were run as controls.