How apicomplexan parasites move in and out of cells.

Apicomplexan parasites utilize a unique form of 'gliding motility' to traverse across substrates, migrate through tissues, and invade into and finally egress from their vertebrate host cells. Parasite gliding relies on the treadmilling of surface adhesins linked to short actin filaments that are translocated rearward by stationary small myosin motors. New details reveal mechanistic insight into the coordinated release and processing of adhesins, the complexity of adhesin-substrate interactions, the regulation of the actin-myosin motor complex, and the formation of a novel junction at the host-parasite interface. These activities are carefully orchestrated to provide an efficient process for motility that is essential for parasite survival. The parasite-specific nature of many of these steps reveals several essential points that may be targeted for intervention.