Protein: Cysteine-rich protective antigen (Inactive sialidase CyRPA) (Q8IFM8)
Organism: Plasmodium falciparum (isolate 3D7)
Function: Essential for the invasion of host erythrocytes by blood stage merozoites. Required for the assembly of the PfRH5 adhesion complex (or invasion complex) composed of CyRPA, RH5 and RIPR at the interface between the merozoite and the host erythrocyte membranes. This facilitates the binding of RH5 to host receptor BSG/basigin, which leads to the establishment of a tight junction between the merozoite and host erythrocyte membranes and allows Ca(2+) release into the erythrocyte.
Subcellular location: Secreted {ECO:0000269|PubMed:25583518}. Cytoplasmic vesicle, secretory vesicle, microneme lumen {ECO:0000269|PubMed:25583518}. Cell membrane {ECO:0000269|PubMed:22593616, ECO:0000269|PubMed:25583518}; Peripheral membrane protein {ECO:0000269|PubMed:22593616, ECO:0000269|PubMed:25583518}; Extracellular side {ECO:0000269|PubMed:22593616, ECO:0000269|PubMed:25583518}. Host cell membrane {ECO:0000269|PubMed:25583518, ECO:0000269|PubMed:27374406, ECO:0000269|PubMed:30542156}. Note=In late schizonts, colocalizes with RIPR in the microneme lumen (PubMed:22593616, PubMed:25583518, PubMed:27374406). During merozoite invasion of host erythrocytes, secreted at the merozoite apical surface where it colocalizes with RIPR and RH5 at the interface between the merozoite and the erythrocyte (PubMed:25583518, PubMed:27374406). {ECO:0000269|PubMed:22593616, ECO:0000269|PubMed:25583518, ECO:0000269|PubMed:27374406}.
Sequence: MIIPFHKKFISFFQIVLVVLLLCRSINCDSRHVFIRTELSFIKNNVPCIRDMFFIYKRELYNICLDDLKGEEDETHIYVQKKVKDSWITLNDLFKETDLTGRPHIFAYVDVEEIIILLCEDEEFSNRKKDMTCHRFYSNDGKEYNNSEITISDYILKDKLLSSYVSLPLKIENREYFLICGVSPYKFKDDNKKDDILCMASHDKGETWGTKIVIKYDNYKLGVQYFFLRPYISKNDLSFHFYVGDNINNVKNVNFIECTHEKDLEFVCSNRDFLKDNKVLQDVSTLNDEYIVSYGNDNNFAECYIFFNNENSILIKPEKYGNTTAGCYGGTFVKIDENRTLFIYSSSQGIYNIHTIYYANYE
InterPro domains: - IPR041396: Cysteine-rich protective antigen 6 bladed domain (domain) [39-353]
Interaction partners: - Reticulocyte-binding protein homolog 5
- Rh5-interacting protein
Gene Ontology annotations:
Molecular Function (MF): GO:0003674 (molecular function), GO:0005488 (binding), GO:0005515 (protein binding)
Biological Process (BP): GO:0008150 (biological process), GO:0008152 (metabolic process), GO:0009987 (cellular process), GO:0044237 (cellular metabolic process), GO:0044238 (primary metabolic process), GO:0071704 (organic substance metabolic process), GO:0006807 (nitrogen compound metabolic process), GO:0005975 (carbohydrate metabolic process), GO:1901564 (organonitrogen compound metabolic process), GO:0019538 (protein metabolic process), GO:0044260 (cellular macromolecule metabolic process), GO:0043170 (macromolecule metabolic process), GO:1901135 (carbohydrate derivative metabolic process), GO:0036211 (protein modification process), GO:0043412 (macromolecule modification), GO:0009100 (glycoprotein metabolic process), GO:0006517 (protein deglycosylation)
Cellular Component (CC): GO:0005575 (cellular component), GO:0110165 (cellular anatomical entity), GO:0005622 (intracellular anatomical structure), GO:0043226 (organelle), GO:0005737 (cytoplasm), GO:0005773 (vacuole), GO:0043229 (intracellular organelle), GO:0043227 (membrane-bounded organelle), GO:0000323 (lytic vacuole), GO:0043231 (intracellular membrane-bounded organelle), GO:0005764 (lysosome)