Simplified schematic representation of heterologously expressed PGIPs and PGs.
A, mature, soluble PGIP expressed in the yeast Kluyveromyces lactis. B, immature, pre-processed PGIP_GPI expressed in Sf9 insect cells. C, mature, membrane-anchored PGIP_GPI expressed on the extracellular surface of Sf9 insect cells. D, soluble PGIP_GPI after release from the membrane by PI-PLC treatment. E, mature, soluble PG expressed in the yeast Pichia pastoris. For detailed sequences see supporting information 2. SP, signal peptide for extracellular localization; myc, His6 and V5, protein tags for immunoblot detection or purification; GPI SP, GPI attachment signal peptide; S, 15-amino-acid spacer; omega site, GPI attachment site.