title: Sexual stage adhesion proteins form multi-protein complexes in the malaria parasite Plasmodium falciparum.
abstract: The sexual phase of the malaria parasite Plasmodium falciparum is accompanied by the coordinated expression of stage-specific adhesive proteins. Among these are six secreted proteins with multiple adhesion domains, termed P. falciparum LCCL domain-containing protein (PfCCp) proteins, which are expressed in the parasitophorous vacuole of the differentiating gametocytes and which are later associated with macrogametes. Although the majority of the PfCCp proteins are implicated in parasite development in the mosquito vector, their functions remain unknown. In the present study we investigated the molecular interactions between the PfCCp proteins during gametocyte development and emergence. Using five different gene-disruptant parasite lines, we show that the lack of one PfCCp protein leads to the loss of other PfCCp family members. Co-immunoprecipitation assays on gametocyte lysates revealed formation of complexes involving all PfCCp proteins, and affinity chromatography co-elution binding assays with recombinant PfCCp domains further indicated direct binding between distinct adhesion domains. PfCCp-coated latex beads bind to newly formed macrogametes but not to gametocytes or older macrogametes 6 or 24 h post-activation. In view of these data, we propose that the PfCCp proteins form multi-protein complexes that are exposed during gametogenesis, thereby mediating cell contacts of macrogametes.
authors.affiliation: Research Center for Infectious Diseases, University of Würzburg, Röntgenring 11, 97070 Würzburg, Germany.
authors.forename: Nina
authors.initials: N
authors.lastname: Simon
authors.forename: Sabrina M
authors.initials: SM
authors.lastname: Scholz
authors.forename: Cristina K
authors.initials: CK
authors.lastname: Moreira
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Templeton
authors.forename: Andrea
authors.initials: A
authors.lastname: Kuehn
authors.forename: Marie-Adrienne
authors.initials: MA
authors.lastname: Dude
authors.forename: Gabriele
authors.initials: G
authors.lastname: Pradel
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002448:Cell Adhesion; D002457:Cell Extracts; D017353:Gene Deletion; D016778:Malaria, Falciparum / Q000469:parasitology*; D008954:Models, Biological; D046912:Multiprotein Complexes / Q000378:metabolism*; D010271:Parasites / Q000166:cytology / Q000378:metabolism*; D010963:Plasmodium falciparum / Q000166:cytology / Q000378:metabolism*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D015800:Protozoan Proteins / Q000737:chemistry / Q000378:metabolism*
chemical_list: D002457:Cell Extracts; D046912:Multiprotein Complexes; D015800:Protozoan Proteins; C064783:sexual stage specific protein, Plasmodium