An F2A sequence permits correct localization of a secreted and a nuclear localized reporter in C. elegans.

Multicistronic expression systems enable production of multiple proteins from a single transcript, with internal ribosome entry sites (IRES), SL2 trans-splicing, and 2A peptides as common tools. Because 2A peptides rely on a single translation event, we tested whether nuclear-localized mStayGold (mSG::H2B) and secreted mScarlet (ssmScarlet) reporters separated by F2A in C. elegans produced the expected localization pattern. mSG::H2B::F2A::ssmScarlet and ssmScarlet::F2A::mSG::H2B expressed in body wall muscle produced nuclear mSG in muscle and ssmScarlet in coelomocytes, indicating that downstream secreted proteins could be correctly directed to the secretory pathway. These data provide a configuration for driving nuclear and secreted proteins from a single-copy transgene.