PfRH1

PfRH1, or Plasmodium falciparum reticulocyte-binding protein homolog 1, is a member of the PfRh protein family that functions as a merozoite surface invasion ligand in the malaria parasite. PfRh proteins are secreted during invasion and contribute to the recognition and entry of merozoites into human erythrocytes. PfRH1 is expressed in the merozoite stage and is trafficked to the parasite surface during the invasion process, where it is thought to participate in engagement with host cell receptors and to facilitate entry.

Genetic and functional studies indicate that pfRh1 exhibits variation among parasite isolates, with such diversity correlating with differences in invasion pathways and erythrocyte preferences. PfRH1 can operate in pathways that function alongside or as alternatives to other invasion ligands, including members of the EBA and PfRh families, thereby providing flexibility in host cell entry. Disruption of pfRh1 or antibody-mediated inhibition has been shown to reduce invasion efficiency in certain parasite strains, supporting a role in host cell recognition and entry.

The precise erythrocyte receptor(s) for PfRH1 remain an area of ongoing research. PfRH1 is often studied in the broader context of parasite invasion biology and in relation to other invasion ligands, as understanding its function helps explain the parasite’s adaptability to diverse host cells and informs efforts toward vaccine development targeting invasion mechanisms. Research on PfRH1 typically involves expression and localization studies, as well as functional assays assessing its contribution to merozoite invasion.