title: A conserved region in the EBL proteins is implicated in microneme targeting of the malaria parasite Plasmodium falciparum.
abstract: The proliferation of the malaria parasite Plasmodium falciparum within the human host is dependent upon invasion of erythrocytes. This process is accomplished by the merozoite, a highly specialized form of the parasite. Secretory organelles including micronemes and rhoptries play a pivotal role in the invasion process by storing and releasing parasite proteins. The mechanism of protein sorting to these compartments is unclear. Using a transgenic approach we show that trafficking of the most abundant micronemal proteins (members of the EBL-family: EBA-175, EBA-140/BAEBL, and EBA-181/JSEBL) is independent of their cytoplasmic and transmembrane domains, respectively. To identify the minimal sequence requirements for microneme trafficking, we generated parasites expressing EBA-GFP chimeric proteins and analyzed their distribution within the infected erythrocyte. This revealed that: (i) a conserved cysteine-rich region in the ectodomain is necessary for protein trafficking to the micronemes and (ii) correct sorting is dependent on accurate timing of expression.
authors.affiliation: Bernhard Nocht Institute for Tropical Medicine, Malaria II, 20359 Hamburg, Germany.
authors.forename: Moritz
authors.initials: M
authors.lastname: Treeck
authors.forename: Nicole S
authors.initials: NS
authors.lastname: Struck
authors.forename: Silvia
authors.initials: S
authors.lastname: Haase
authors.forename: Christine
authors.initials: C
authors.lastname: Langer
authors.forename: Susann
authors.initials: S
authors.lastname: Herrmann
authors.forename: Julie
authors.initials: J
authors.lastname: Healer
authors.forename: Alan F
authors.initials: AF
authors.lastname: Cowman
authors.forename: Tim W
authors.initials: TW
authors.lastname: Gilberger
mesh_terms: D000818:Animals; D000953:Antigens, Protozoan / Q000378:metabolism*; D001692:Biological Transport; D002352:Carrier Proteins / Q000378:metabolism*; D017124:Conserved Sequence; D003593:Cytoplasm / Q000378:metabolism; D006056:Golgi Apparatus / Q000378:metabolism; D006801:Humans; D008565:Membrane Proteins; D008856:Microscopy, Fluorescence; D010963:Plasmodium falciparum / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D015800:Protozoan Proteins / Q000737:chemistry / Q000378:metabolism*; D014162:Transfection
chemical_list: D000953:Antigens, Protozoan; D002352:Carrier Proteins; C474029:EBA-181 protein, Plasmodium falciparum; C438380:EBA140 protein, Plasmodium falciparum; D008565:Membrane Proteins; D015800:Protozoan Proteins; C065668:erythrocyte-binding antigen 175, Plasmodium