Type III secretion: more systems than you think

Physiology (Bethesda). 2005 Oct;20:326-39. doi: 10.1152/physiol.00011.2005.


The type III secretion (T3S) pathway allows bacteria to inject effector proteins into the cytosol of target animal or plant cells. T3S systems evolved into seven families that were distributed among Gram-negative bacteria by horizontal gene transfer. There are probably a few hundred effectors interfering with control and signaling in eukaryotic cells and offering a wealth of new tools to cell biologists.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Evolution, Molecular
  • Gram-Negative Bacteria / metabolism*
  • Humans
  • Multigene Family
  • Plants / microbiology


  • Bacterial Proteins