title: Are rhoptries in Apicomplexan parasites secretory granules or secretory lysosomal granules?
abstract: The club-shaped rhoptries in Apicomplexan parasites are one of the most unusual secretory organelles among the eukaryotes, containing unusual lipid and protein cargo that is specialized for intracellular parasitism. Rhoptries have traditionally been viewed strictly as regulated secretory granules. We discuss in this article recent data on the cargo, function and biogenesis of rhoptries in two parasitic model systems, Toxoplasma and Plasmodium. Current findings suggest that rhoptries receive products from both biosynthetic and endocytic pathways and, therefore, they are most analogous to secretory lysosomal granules found in mammalian cells.
authors.affiliation: Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06520-8022, USA.
authors.forename: Huân M
authors.initials: HM
authors.lastname: Ngô
authors.forename: Mei
authors.initials: M
authors.lastname: Yang
authors.forename: Keith A
authors.initials: KA
authors.lastname: Joiner
mesh_terms: D000818:Animals; D016782:Apicomplexa / Q000378:metabolism* / Q000648:ultrastructure*; D008247:Lysosomes / Q000737:chemistry / Q000000981:diagnostic imaging / Q000378:metabolism*; D010961:Plasmodium / Q000378:metabolism / Q000648:ultrastructure; D022142:Secretory Vesicles / Q000737:chemistry / Q000378:metabolism* / Q000648:ultrastructure; D014122:Toxoplasma / Q000378:metabolism / Q000648:ultrastructure; D014463:Ultrasonography