Figure 8.

The RSE may act as an NMD insulator. Either through a direct interaction with the RNA, or mediated through a protein, the RSE may act as an NMD insulator. A. The RSE may act as a decoy to conceal the gag stop codon from association with some NMD factors or to interact with Smg8/9 to keep Smg1 inactive. B. The RSE may interact with the translation termination machinery at a site that overlaps with that of Upf1, such that the NMD machinery can no longer associate with eRF3. C. The RSE may interact with eRF3 to promote translation termination. D. The RSE may interact directly with one of the ribosomal subunits to induce a conformational change that favors translation termination.