Conservation of a gliding motility and cell invasion machinery in Apicomplexan parasites

Most Apicomplexan parasites, including the human pathogens Plasmodium, Toxo plasma, and Cryptosporidium, actively invade host cells and display gliding motility, both actions powered by parasite microfilaments. In Plasmodium s porozoites, thrombospondin-related anonymous protein (TRAP), a member of a group of Apicomplexan transmembrane proteins that have common adhesion doma ins, is necessary for gliding motility and infection of the vertebrate host . Here, we provide genetic evidence that TRAP is directly involved in a cap ping process that drives both sporozoite gliding and cell invasion. We also demonstrate that TRAP-related proteins in other Apicomplexa fulfill the sa me function and that their cytoplasmic tails interact with homologous partn ers in the respective parasite. Therefore, a mechanism of surface redistrib ution of TRAP-related proteins driving gliding locomotion and cell invasion is conserved among Apicomplexan parasites.