Essential for the invasion of host erythrocytes by blood stage merozoites (PubMed:21909261, PubMed:25583518, PubMed:27374406, PubMed:27692771). As part of the PfRH5 adhesion complex, facilitates the interaction of RH5 and human BSG required for the Ca(2+) release into the erythrocyte (PubMed:27374406). Component of the PfRH5 adhesion complex composed of 1 copy of CyRPA, RH5 and RIPR; the complex is formed during merozoite invasion of host erythrocytes specifically at the interface between the parasite and host membranes (PubMed:21909261, PubMed:25583518, PubMed:27374406, PubMed:28186186, PubMed:30542156). Within the complex, interacts with CyRPA (PubMed:28186186, PubMed:30542156). CyRPA recruitment of RIPR to RH5-P113-BSG leads to the formation of the PfRH5 adhesion complex which probably in turn releases RH5 from P113 while maintaining the interaction of the PfRH5 adhesion complex with BSG (PubMed:28186186). In late schizonts, colocalizes with CyRPA in the microneme lumen (PubMed:21909261, PubMed:25583518, PubMed:27374406, PubMed:27692771). During merozoite invasion of host erythrocytes, secreted at the merozoite apical surface where it colocalizes with CyPRA and RH5 at the interface between the merozoite and the erythrocyte (PubMed:27374406, PubMed:21909261, PubMed:25583518). Expressed in late throphozoide to schizonts and in merozoites (at protein level). Proteolytically cleaved into two chains of 125kDa and 65kDa which remain associated. The cleavage occurs at the schizont stage prior to the release of merozoites. Contains disulfide bonds. Conditional knockdown causes loss of cell growth and severely impairs merozoite invasion of erythrocytes. Attachment to and deformation of erythrocyte membrane is normal, however the subsequent step, which triggers an increase in Ca(2+) from the attached merozoite into the erythrocyte, is impaired. Potential candidate for the development of parasite blood stage vaccines. In vitro and in vivo, induces neutralizing antibodies capable of inhibiting merozoite invasion of host erythrocytes.