title: Evidence for filamentous actin in ookinetes of a malarial parasite.
abstract: Extracellular stages of apicomplexan parasites utilize their own actin myosin motor machinery for gliding locomotion, penetration of cell barriers, and host cell invasion. Thus far, filamentous actin could not be visualized by standard microscopic techniques in vivo. Here, we describe the generation of a novel peptide antibody against the divergent amino-terminal portion of the major Plasmodium isoform, actin I. We show that our antiserum, termed Ab-actinI-I, is conformation-specific. In motile ookinetes it recognizes actin in rod-like structures, which are sensitive to inhibitors interfering with actin polymerization. The average size of the rods is 600 nm, which is considerably longer than what has been detected in in vitro studies of actin filaments.
authors.affiliation: Institute of Molecular Biology and Biotechnology, FORTH, N. Plastira 100, Vassilika Vouton, Heraklion 700 13, Crete, Greece. inga@imbb.forth.gr
authors.forename: Inga
authors.initials: I
authors.lastname: Siden-Kiamos
authors.forename: Christos
authors.initials: C
authors.lastname: Louis
authors.forename: Kai
authors.initials: K
authors.lastname: Matuschewski
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism*; D000199:Actins / Q000378:metabolism; D000595:Amino Acid Sequence; D000913:Antibodies, Protozoan / Q000378:metabolism; D007106:Immune Sera / Q000378:metabolism; D010961:Plasmodium / Q000378:metabolism*; D015800:Protozoan Proteins / Q000378:metabolism*; D016415:Sequence Alignment; D013194:Staining and Labeling
chemical_list: D000199:Actins; D000913:Antibodies, Protozoan; D007106:Immune Sera; D015800:Protozoan Proteins