Elimination of a bacterial pore-forming toxin by sequential endocytosis and exocytosis

FEBS Lett. 2009 Jan 22;583(2):337-44. doi: 10.1016/j.febslet.2008.12.028. Epub 2008 Dec 25.

Abstract

Staphylococcus aureus alpha-toxin is the archetype of bacterial pore forming toxins and a key virulence factor secreted by the majority of clinical isolates of S. aureus. Toxin monomers bind to target cells and oligomerize to form small beta-barrel pores in the plasma membrane. Many nucleated cells are able to repair a limited number of lesions by unknown, calcium-independent mechanisms. Here we show that cells can internalize alpha-toxin, that uptake is essential for cellular survival, and that pore-complexes are not proteolytically degraded, but returned to the extracellular milieu in the context of exosome-like structures, which we term toxosomes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bacterial Toxins / genetics
  • Bacterial Toxins / metabolism*
  • COS Cells
  • Cell Line
  • Cell Nucleus / metabolism
  • Chlorocebus aethiops
  • Endocytosis* / drug effects
  • Endosomes / metabolism
  • Exocytosis* / drug effects
  • Hemolysin Proteins / genetics
  • Hemolysin Proteins / metabolism*
  • Humans
  • Macrolides / pharmacology
  • Mutation

Substances

  • Bacterial Toxins
  • Hemolysin Proteins
  • Macrolides
  • staphylococcal alpha-toxin
  • bafilomycin A