PfRh5interacting

PfRh5 interacting refers to the network of molecular interactions involving the Plasmodium falciparum RH5 ligand and its partners during merozoite invasion of human red blood cells. PfRh5 is a secreted protein essential for invasion and binds the erythrocyte receptor basigin (CD147), a key step in triggering entry.

PfRh5 does not act alone. It forms a trimeric complex with two parasite proteins, Ripr (RH5 interacting protein) and CyRPA (cyclic rhoptry protein A). This RH5-Ripr-CyRPA complex stabilizes PfRh5 and is required for efficient engagement of basigin. The interactions within the complex are coordinated to present a functional binding surface for the receptor on the erythrocyte.

The interaction with basigin is central to the invasion process. Binding of the PfRh5-containing complex to basigin facilitates signaling and reorganization of the merozoite surface and invasion machinery, enabling entry into the red blood cell. Disruption of any component of the complex, or interference with the PfRh5-basigin interaction, typically blocks invasion in vitro and reduces parasite fitness.

Immunological and translational relevance is high. PfRh5 is one of the most conserved and essential invasion ligands, with limited polymorphism across isolates, making it an attractive vaccine target. Antibodies or inhibitors that block PfRh5, Ripr, or CyRPA functions can prevent basigin engagement and merozoite invasion, informing ongoing vaccine and therapeutic development.

Ongoing research continues to define the precise interfaces and structural basis of PfRh5 interactions, with the aim of refining intervention strategies against blood-stage malaria.