The exocyst is required for trypanosome invasion and the repair of mechanical plasma membrane wounds.
The process of host cell invasion by Trypanosoma cruzi shares mechanistic elements with plasma membrane injury and repair. Both processes require Ca(2+)-triggered exocytosis of lysosomes, exocytosis of acid sphingomyelinase and formation of ceramide-enriched endocytic compartments. T. cruzi invades at peripheral sites, suggesting a need for spatial regulation of membrane traffic. Here, we show that Exo70 and Sec8 (also known as EXOC7 and EXOC4, respectively), components of the exocyst complex, accumulate in nascent T. cruzi vacuoles and at sites of mechanical wounding. Exo70 or Sec8 depletion inhibits T. cruzi invasion and Ca(2+)-dependent resealing of mechanical wounds, but does not affect the repair of smaller lesions caused by pore-forming toxins. Thus, T. cruzi invasion and mechanical lesion repair share a unique requirement for the exocyst, consistent with a dependence on targeted membrane delivery.
Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742-5815, USA.
Maria Cecilia
MC
Fernandes
Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742-5815, USA.
Matthias
M
Corrotte
Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742-5815, USA.
Danilo C
DC
Miguel
Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742-5815, USA.
Christina
C
Tam
Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742-5815, USA andrewsn@umd.edu.
Norma W
NW
Andrews
D002118:Calcium / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism* / Q000473:pathology; D014355:Chagas Disease / Q000378:metabolism* / Q000473:pathology; D004705:Endocytosis; D006367:HeLa Cells; D006801:Humans; D014349:Trypanosoma cruzi / Q000378:metabolism*; D033921:Vesicular Transport Proteins / Q000378:metabolism*
C489607:EXOC4 protein, human; C547754:EXOC7 protein, human; D033921:Vesicular Transport Proteins; D002118:Calcium
Infection; Resealing; Trypanosome