title: Cytoskeletal components of an invasion machine--the apical complex of Toxoplasma gondii.
abstract: The apical complex of Toxoplasma gondii is widely believed to serve essential functions in both invasion of its host cells (including human cells), and in replication of the parasite. The understanding of apical complex function, the basis for its novel structure, and the mechanism for its motility are greatly impeded by lack of knowledge of its molecular composition. We have partially purified the conoid/apical complex, identified approximately 200 proteins that represent 70% of its cytoskeletal protein components, characterized seven novel proteins, and determined the sequence of recruitment of five of these proteins into the cytoskeleton during cell division. Our results provide new markers for the different subcompartments within the apical complex, and revealed previously unknown cellular compartments, which facilitate our understanding of how the invasion machinery is built. Surprisingly, the extreme apical and extreme basal structures of this highly polarized cell originate in the same location and at the same time very early during parasite replication.
authors.affiliation: Department of Cell Biology, Scripps Research Institute, La Jolla, California, United States of America.
authors.forename: Ke
authors.initials: K
authors.lastname: Hu
authors.forename: Jeff
authors.initials: J
authors.lastname: Johnson
authors.forename: Laurence
authors.initials: L
authors.lastname: Florens
authors.forename: Martin
authors.initials: M
authors.lastname: Fraunholz
authors.forename: Sapna
authors.initials: S
authors.lastname: Suravajjala
authors.forename: Camille
authors.initials: C
authors.lastname: DiLullo
authors.forename: John
authors.initials: J
authors.lastname: Yates
authors.forename: David S
authors.initials: DS
authors.lastname: Roos
authors.forename: John M
authors.initials: JM
authors.lastname: Murray
mesh_terms: D000818:Animals; D003599:Cytoskeleton / Q000737:chemistry / Q000502:physiology*; D005347:Fibroblasts / Q000469:parasitology; D052816:Foreskin / Q000166:cytology; D006790:Host-Parasite Interactions; D006801:Humans; D008297:Male; D015388:Organelles / Q000502:physiology*; D015800:Protozoan Proteins / Q000032:analysis / Q000235:genetics / Q000502:physiology; D053719:Tandem Mass Spectrometry; D014122:Toxoplasma / Q000737:chemistry / Q000472:pathogenicity* / Q000502:physiology / Q000648:ultrastructure; D014123:Toxoplasmosis / Q000469:parasitology*
chemical_list: D015800:Protozoan Proteins