title: Plasmodium berghei ookinetes bind to Anopheles gambiae and Drosophila melanogaster annexins.
abstract: Using a proteomic approach we identified polypeptides from Anopheles gambiae and Drosophila melanogaster protein extracts that selectively bind purified Plasmodium berghei ookinetes in vitro; these were two and three distinct polypeptides, respectively, with an apparent molecular weight of about 36 kDa. Combining two-dimensional electrophoresis and MALDI-TOF (matrix-associated laser desorption ionization time of flight) mass spectrometry we determined that the polypeptides correspond to isomorphs of the annexin B11 protein of the fruit fly. When protein extracts derived from A. gambiae and D. melanogaster tissue culture cells were further fractionated, the binding activity matching the annexin protein could be localized in the fraction derived from cell membranes in both diptera. Antibody staining showed that annexin also binds to ookinetes during the invasion of the mosquito midgut. Finally, inclusion of antiannexin antisera in a mosquito blood meal impaired parasite development, suggesting a facilitating role for annexins in the infection of the mosquito by Plasmodium.
authors.affiliation: Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology - Hellas, Vassilika Vouton, PO Box 1527, 71110 Heraklion, Crete, Greece.
authors.forename: Michalis
authors.initials: M
authors.lastname: Kotsyfakis
authors.forename: Laurence
authors.initials: L
authors.lastname: Ehret-Sabatier
authors.forename: Inga
authors.initials: I
authors.lastname: Siden-Kiamos
authors.forename: Jaqueline
authors.initials: J
authors.lastname: Mendoza
authors.forename: Robert E
authors.initials: RE
authors.lastname: Sinden
authors.forename: Christos
authors.initials: C
authors.lastname: Louis
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017302:Annexins / Q000276:immunology / Q000378:metabolism*; D000852:Anopheles / Q000469:parasitology*; D001769:Blood / Q000469:parasitology; D002478:Cells, Cultured; D004331:Drosophila melanogaster / Q000469:parasitology*; D041981:Gastrointestinal Tract / Q000166:cytology / Q000469:parasitology; D007106:Immune Sera / Q000494:pharmacology; D019476:Insect Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D007303:Insect Vectors / Q000187:drug effects / Q000378:metabolism*; D008288:Malaria / Q000469:parasitology / Q000635:transmission; D051379:Mice; D008969:Molecular Sequence Data; D010962:Plasmodium berghei / Q000302:isolation & purification / Q000472:pathogenicity* / Q000502:physiology; D040901:Proteomics / Q000379:methods; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods
chemical_list: D017302:Annexins; D007106:Immune Sera; D019476:Insect Proteins