title: A novel dynamin-related protein has been recruited for apicoplast fission in Toxoplasma gondii.
abstract: BACKGROUND
  Apicomplexan parasites cause numerous important human diseases, including malaria and toxoplasmosis. Apicomplexa belong to the Alveolata, a group that also includes ciliates and dinoflagellates. Apicomplexa retain a plastid organelle (the apicoplast) that was derived from an endosymbiotic relationship between the alveolate ancestor and a red alga. Apicoplasts are essential for parasite growth and must correctly divide and segregate into daughter cells upon cytokinesis. Apicoplast division depends on association with the mitotic spindle, although little is known about the molecular machinery involved in this process. Apicoplasts lack the conserved machinery that divides chloroplasts in plants and red algae, suggesting that these mechanisms are unique.
  
  
  RESULTS
  Here, we demonstrate that a dynamin-related protein in Toxoplasma gondii (TgDrpA) localizes to punctate regions on the apicoplast surface. We generate a conditional dominant-negative TgDrpA cell line to disrupt TgDrpA functions and demonstrate that TgDrpA is essential for parasite growth and apicoplast biogenesis. Fluorescence recovery after photobleaching and time-lapse imaging studies provide evidence for a direct role for TgDrpA in apicoplast fission.
  
  
  CONCLUSIONS
  Our data suggest that DrpA was likely recruited from the alveolate ancestor to function in fission of the symbiont and ultimately replaced the conserved division machinery of that symbiont.
authors.affiliation: Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, 30602, USA.
authors.forename: Giel G
authors.initials: GG
authors.lastname: van Dooren
authors.forename: Sarah B
authors.initials: SB
authors.lastname: Reiff
authors.forename: Cveta
authors.initials: C
authors.lastname: Tomova
authors.forename: Markus
authors.initials: M
authors.lastname: Meissner
authors.forename: Bruno M
authors.initials: BM
authors.lastname: Humbel
authors.forename: Boris
authors.initials: B
authors.lastname: Striepen
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D034281:Dynamins / Q000235:genetics / Q000378:metabolism*; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D006801:Humans; D008869:Microtubule-Associated Proteins / Q000145:classification / Q000235:genetics / Q000378:metabolism; D015388:Organelles / Q000378:metabolism* / Q000648:ultrastructure; D010802:Phylogeny; D015800:Protozoan Proteins / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D014122:Toxoplasma / Q000166:cytology / Q000378:metabolism
chemical_list: D008869:Microtubule-Associated Proteins; D015800:Protozoan Proteins; D011993:Recombinant Fusion Proteins; D034281:Dynamins