41
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: not found

      Sequential protein secretion from three distinct organelles of Toxoplasma gondii accompanies invasion of human fibroblasts.

      European Journal of Cell Biology

      Acid Anhydride Hydrolases, ultrastructure, metabolism, Vacuoles, physiology, pathogenicity, Toxoplasma, Solubility, secretion, Protozoan Proteins, Organelles, Nucleoside-Triphosphatase, Models, Biological, Microscopy, Immunoelectron, Microscopy, Fluorescence, Kinetics, In Vitro Techniques, Humans, parasitology, Fibroblasts, Cytoplasmic Granules, Cells, Cultured, Animals

      Read this article at

      ScienceOpenPubMed
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Invasion of vertebrate cells by the protozoan Toxoplasma gondii is accompanied by regulated protein secretion from three distinct parasite organelles called micronemes, rhoptries, and dense granules. We have compared the kinetics of secretion from these different compartments during host cell invasion using immunofluorescence, immunoelectron microscopy, and quantitative immunoassays. Binding to the host cell triggered apical release of the micronemal protein MIC2 at the tight attachment zone that forms between the parasite and the host cell. In a second step, invagination of the host cell plasma membrane was initiated by discharge of the rhoptry protein ROP1 to form a nascent parasitophorous vacuole (PV). ROP1 was fully discharged into the vacuole by the time invasion was complete. In contrast to these very rapid early events, release of the dense granule markers GRA1 and NTPase was delayed until after the parasite was fully within the PV, eventually peaking at 20 min post-invasion. The sequential triggering of secretion from different organelles implies that their release is governed by separate signals and that their contents mediate distinct phases of intracellular parasitism.

          Related collections

          Author and article information

          Journal
          9208224

          Comments

          Comment on this article