The Apicomplexan CDC/MACPF-like pore-forming proteins

Pore-forming proteins (PFPs) encompass a broad family of proteins that are used for virulence or immune defense. Members of the cholesterol-dependent cytolysins (CDCs) and membrane attack complex/perforin (MACPF) family of PFPs form large β-barrel pores in the membrane. The CDC/MACPF proteins contain a characteristic four-stranded β-sheet that is flanked by two α-helical bundles, which unfold to form two transmembrane β-hairpins. Apicomplexan eukaryotic parasites express CDC/MACPFs termed perforin-like proteins (PLPs). Here we review recent studies that provide key insights into the assembly and regulation of the Apicomplexan PLP (ApiMACPF) molecular pore-forming mechanisms, which are necessary for the osmotically driven rupture of the parasitophorous vacuole and host cell membrane, and cell traversal by these parasites.