title: The Plasmodium falciparum Vps4 homolog mediates multivesicular body formation.
abstract: Members of the apicomplexan family of parasites contain morphologically unique secretory organelles termed rhoptries that are essential for host cell invasion. Rhoptries contain internal membranes, and thus resemble multivesicular bodies. To determine whether multivesicular body endosomal intermediates are formed in Apicomplexa, we used the Plasmodium falciparum homolog of the class E gene, Vps4, as a probe. Endogenous P. falciparum Vps4 (PfVps4) localized to the cytoplasm of P. falciparum trophozoites, and transgenic PfVps4 localized to the cytosol in P. falciparum, in the related parasite Toxoplasma gondii and in COS cells. When mutated to block ATP hydrolysis, transiently expressed PfVps4 localized instead to large vesicular structures in P. falciparum. The same construct, and another mutant blocked in ATP binding, generated large cholesterol-enriched multivesicular bodies in both COS cells and T. gondii. Mutant PfVps4 structures in T. gondii co-localized with markers for early endosomes. These results demonstrate a conservation of Vps4 function across wide phylogenetic boundaries, and indicate that endosomal multivesicular bodies form in both P. falciparum and T. gondii.
authors.affiliation: Yale University School of Medicine, Department of Medicine, Section of Infectious Disease, 333 Cedar Street, PO Box 208022, New Haven, CT 06520-8022, USA.
authors.forename: Mei
authors.initials: M
authors.lastname: Yang
authors.forename: Isabelle
authors.initials: I
authors.lastname: Coppens
authors.forename: Steve
authors.initials: S
authors.lastname: Wormsley
authors.forename: Pavlina
authors.initials: P
authors.lastname: Baevova
authors.forename: Heinrich C
authors.initials: HC
authors.lastname: Hoppe
authors.forename: Keith A
authors.initials: KA
authors.lastname: Joiner
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism* / Q000502:physiology*; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D019556:COS Cells; D049109:Cell Proliferation; D002784:Cholesterol / Q000378:metabolism; D003001:Cloning, Molecular; D003593:Cytoplasm / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D018274:Electroporation; D056827:Endosomal Sorting Complexes Required for Transport; D011992:Endosomes / Q000378:metabolism; D005347:Fibroblasts / Q000469:parasitology; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006801:Humans; D006868:Hydrolysis; D015151:Immunoblotting; D008077:Lipoproteins, LDL / Q000378:metabolism; D008854:Microscopy, Electron; D009154:Mutation; D010802:Phylogeny; D010963:Plasmodium falciparum / Q000378:metabolism / Q000502:physiology*; D017434:Protein Structure, Tertiary; D015800:Protozoan Proteins; D013347:Subcellular Fractions; D014122:Toxoplasma; D014162:Transfection; D019076:Transgenes
chemical_list: D056827:Endosomal Sorting Complexes Required for Transport; D008077:Lipoproteins, LDL; D015800:Protozoan Proteins; D049452:Green Fluorescent Proteins; D000255:Adenosine Triphosphate; D004247:DNA; D002784:Cholesterol; D000251:Adenosine Triphosphatases; C498348:Vps4 protein, Plasmodium falciparum