FIGURE 3.

Tethered dUNR represses translation. (A) Schematic diagram of the RNA constructs used in translation assays. BLEF mRNA (see Fig. 1 legend) and derivatives are depicted. Wild-type and mutated SXL-binding sites are shown as black and gray ovals, respectively. Hairpins denote the substitution of the 3′UTR by nine MS2 binding sites. (B) Tethered dUNR represses translation. BLEF, BLMS2, and BmutLMS2 mRNAs were translated in Drosophila embryo extracts in the presence of increasing amounts of either MS2-dUNR (blue lines) or dRBD4 (red lines). MBP-MS2 was used as a negative control (solid black lines). As reference, the translational repression of BL(EF)mut and BmutLEF mRNAs by SXL was tested (dashed black lines). The translation rate was measured as indicated in the legend of Figure 1 and was plotted against the molar ratio of recombinant protein/RNA.