Plasmodium falciparum exported protein, PTP7, co-immunoprecipitation LC-MSMS

The malaria parasite, Plasmodium falciparum, traffics the virulence protein erythrocyte membrane protein 1 (EMP1) to the surface of infected red blood cells (RBCs) via membranous organelles known as the Maurer’s clefts. How EMP1 is trafficked from the clefts to its site of action at the RBC surface is poorly understood. Here we build upon previous studies (DOI: 10.1128/mBio.03320-19) which had identified the exported Plasmodium protein PF3D7_0301700, or PTP7, as a protein of interest in post-cleft EMP1 trafficking. Transfectants expressing PTP7-GFP confirmed PTP7’s localization to the cleft and association with vesicles and soluble chaperoned complexes also implicated in EMP1 trafficking. Co-immunoprecipitation and mass spectrometry of PTP7-GFP confirmed associations with Maurer’s cleft, vesicle, and chaperone complex proteins as observed by light and electron microscopy. This experiment also expands the network map of exported protein-protein associations characterized to date.