title: An EGF-like protein forms a complex with PfRh5 and is required for invasion of human erythrocytes by Plasmodium falciparum.
abstract: Invasion of erythrocytes by Plasmodium falciparum involves a complex cascade of protein-protein interactions between parasite ligands and host receptors. The reticulocyte binding-like homologue (PfRh) protein family is involved in binding to and initiating entry of the invasive merozoite into erythrocytes. An important member of this family is PfRh5. Using ion-exchange chromatography, immunoprecipitation and mass spectroscopy, we have identified a novel cysteine-rich protein we have called P. falciparumRh5 interacting protein (PfRipr) (PFC1045c), which forms a complex with PfRh5 in merozoites. Mature PfRipr has a molecular weight of 123 kDa with 10 epidermal growth factor-like domains and 87 cysteine residues distributed along the protein. In mature schizont stages this protein is processed into two polypeptides that associate and form a complex with PfRh5. The PfRipr protein localises to the apical end of the merozoites in micronemes whilst PfRh5 is contained within rhoptries and both are released during invasion when they form a complex that is shed into the culture supernatant. Antibodies to PfRipr1 potently inhibit merozoite attachment and invasion into human red blood cells consistent with this complex playing an essential role in this process.
authors: The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.
authors: Lin
authors: L
authors: Chen
authors: Sash
authors: S
authors: Lopaticki
authors: David T
authors: DT
authors: Riglar
authors: Chaitali
authors: C
authors: Dekiwadia
authors: Alex D
authors: AD
authors: Uboldi
authors: Wai-Hong
authors: WH
authors: Tham
authors: Matthew T
authors: MT
authors: O'Neill
authors: Dave
authors: D
authors: Richard
authors: Jake
authors: J
authors: Baum
authors: Stuart A
authors: SA
authors: Ralph
authors: Alan F
authors: AF
authors: Cowman
mesh_terms: D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism*; D004815:Epidermal Growth Factor / Q000378:metabolism*; D004912:Erythrocytes / Q000469:parasitology*; D006801:Humans; D052940:Merozoites / Q000502:physiology; D010963:Plasmodium falciparum / Q000502:physiology*; D015800:Protozoan Proteins / Q000378:metabolism*
chemical_list: D002352:Carrier Proteins; D015800:Protozoan Proteins; C531020:RH5 protein, Plasmodium falciparum; C000622046:Ripr protein, Plasmodium falciparum; D004815:Epidermal Growth Factor