Endocytic Activity by Apicomplexa Parasites

Macromolecules are incorporated by eukaryotic cells through a process known as endocytosis, intensely analyzed in mammalian and yeast cells, but still lacking deep studies in pathogenic protists. Here we present what is presently known on endocytic activity carried out in some members of the Apicomplexa group (mainly concentrated in Plasmodium and Toxoplasma, but with references to Eimeria, Babesia, and Theileria). In most cells, endocytic activity takes place throughout the cell's surface. In apicomplexans, it is restricted to a special surface structure known as a micropore (also called cytostome). Recent studies indicate that several proteins are in the micropore, playing a role in macromolecule uptake from the medium via budding vesicles.