PfPI3K, a phosphatidylinositol-3 kinase from Plasmodium falciparum, is exported to the host erythrocyte and is involved in hemoglobin trafficking.

Polyphosphorylated phosphoinositides (PIPs) are potent second messengers, which trigger a wide variety of signaling and trafficking events in most eukaryotic cells. However, the role and metabolism of PIPs in malaria parasite Plasmodium have remained largely unexplored. Our present studies suggest that PfPI3K, a novel phosphatidylinositol-3-kinase (PI3K) in Plasmodium falciparum, is exported to the host erythrocyte by the parasite in an active form.

Actin is required for endocytic trafficking in the malaria parasite Plasmodium falciparum.

The intra-erythrocytic stages of the malaria parasite endocytose large quantities of the surrounding erythrocyte cytoplasm and deliver it to a digestive food vacuole via endocytic vesicles. Digestion provides amino acids for parasite protein synthesis and is required to maintain the osmotic integrity of the host cell. The parasite endocytic pathway has been described morphologically by electron microscopy, but the molecular mechanisms that mediate and regulate it remain elusive.