Virulence determinant, PTP7, controls vesicle budding from the Maurers clefts, adhesin protein trafficking and host cell remodeling in Plasmodium falciparum

Presentation of the variant antigen, Plasmodium falciparum erythrocyte membrane protein 1 (EMP1), at knob-like protrusions on the surface of infected red blood cells, underpins P. falciparum malaria pathogenicity. Here we describe a protein PF3D7_0301700 (PTP7), that functions at the nexus between the intermediate trafficking organelle, the Maurers cleft, and the infected red blood cell surface. Genetic disruption of PTP7 leads to accumulation of vesicles at the Maurers clefts, grossly aberrant knob morphology, and failure to deliver EMP1 to the red blood cell surface. We show that an expanded low complexity sequence in the C-terminal region of PTP7, found only in the Laverania clade of Plasmodium, is critical for efficient virulence protein trafficking. Author SummaryWe describe a malaria parasite protein involved in virulence factor trafficking (PTP7) that moves between different compartments in the host red blood cell cytoplasm in a stage-dependent manner. Upon disruption of the PTP7 locus, the Maurers cleft trafficking compartments become decorated with vesicles; the knobby protrusions on the host red blood cell surface are depleted and distorted; and trafficking of the virulence protein, EMP1, to the host red blood cell surface is ablated. We provide evidence that a region of PTP7 with low sequence complexity plays an important role in driving fission of vesicles from the Maurers clefts.