Supplementary Figure 6: Schematic representation of N-peptide–triggered Env140-nutR-H6–mediated SEAP expression control in mammalian cells.

In the absence of N-peptide self-cleavage of the designer ribozyme Env140/nutR/H6 embedded in the 3’ untranslated region of a SEAP-encoding mRNA (pPST67[H6]) removes the poly(A) tail which leads to nuclease (red pacman) –mediated destruction and shut down of SEAP expression. However, binding of N-peptide (pSA776) to stem loop II of Env140/nutR/H6 prevents formation of the tertiary inter-loop structures which inactivates the designer ribozyme and SEAP is translated from an intact mRNA exported to the cytosol and efficiently secreted by the host cell.