Plasmodium falciparum: genetic and immunogenic characterisation of the rhoptry neck protein PfRON4.

The Apicomplexan parasites Toxoplasma and Plasmodium, respectively, cause toxoplasmosis and malaria in humans and although they invade different host cells they share largely conserved invasion mechanisms. Plasmodium falciparum merozoite invasion of red blood cells results from a series of co-ordinated events that comprise attachment of the merozoite, its re-orientation, release of the contents of the invasion-related apical organelles (the rhoptries and micronemes) followed by active propulsion of the merozoite into the cell via an actin-myosin motor. During this process, a tight junction between the parasite and red blood cell plasma membranes is formed and recent studies have identified rhoptry neck proteins, including PfRON4, that are specifically associated with the tight junction during invasion.

Ten families of variant genes encoded in subtelomeric regions of multiple chromosomes of Plasmodium chabaudi, a malaria species that undergoes antigenic variation in the laboratory mouse.

The chromosome ends of human malaria parasites harbour many genes encoding proteins that are exported to the surface of infected red cells, often being involved in host-parasite interactions and immune evasion. Unlike other murine malaria parasites Plasmodium chabaudi undergoes antigenic variation during passage in the laboratory mouse and hence is a model suitable for investigation of switching mechanisms. However, little is known about the subtelomeric regions of P.

PlasmoDB: the Plasmodium genome resource. An integrated database providing tools for accessing, analyzing and mapping expression and sequence data (both finished and unfinished).

PlasmoDB (http://PlasmoDB.org) is the official database of the Plasmodium falciparum genome sequencing consortium. This resource incorporates finished and draft genome sequence data and annotation emerging from Plasmodium sequencing projects.