Identification of a new export signal in Plasmodium yoelii: identification of a new exportome.

Development of the erythrocytic malaria parasite requires targeting of parasite proteins into multiple compartments located within and beyond the parasite confine. Beyond the PEXEL/VTS pathway and its characterized players, increasing amount of evidence has highlighted the existence of proteins exported using alternative export-signal(s)/pathway(s); hence, the exportomes currently predicted are incomplete. The nature of these exported proteins which could have a prominent role in most of the Plasmodium species remains elusive. Using P.  yoelii variant proteins, we identified a signal associated to lipophilic region that mediates export of P.  yoelii proteins. This non-PEXEL signal termed PLASMED is defined by semi-conserved residues and possibly a secondary structure. In vivo characterization of exported-proteins indicated that PLASMED is a bona fide export-signal that allowed us to identify an unseen P.  yoelii exportome. The repertoire of the newly predicted exported proteins opens up perspectives for unravelling the remodelling of the host-cell by the parasite, against which new therapies could be elaborated.