Involvement of profilin in the actin-based motility of L. monocytogenes in cells and in cell-free extracts

Cell. 1994 Feb 11;76(3):505-17. doi: 10.1016/0092-8674(94)90114-7.


Within hours of Listeria monocytogenes infection, host cell actin filaments form a dense cloud around the intracytoplasmic bacteria and then rearrange to form a polarized comet tail that is associated with moving bacteria. We have devised a cell-free extract system capable of faithfully reconstituting L. monocytogenes motility, and we have used this system to demonstrate that profilin, a host actin monomer-binding protein, is necessary for bacterial actin-based motility. We find that extracts from which profilin has been depleted do not support comet tail formation or bacterial motility. In extracts and host cells, profilin is localized to the back half of the surface of motile L. monocytogenes, the site of actin filament assembly in the tail. This association is not observed with L. monocytogenes mutants that do not express the ActA protein, a bacterial gene product necessary for motility and virulence. Profilin also fails to bind L. monocytogenes grown outside of host cytoplasm, suggesting that at least one other host cell factor is required for this association.

Publication types

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

MeSH terms

  • Actins / physiology*
  • Animals
  • Bacterial Proteins / biosynthesis
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism
  • Blotting, Western
  • Cell Movement*
  • Cell-Free System
  • Contractile Proteins / physiology
  • Female
  • HeLa Cells
  • Humans
  • Listeria monocytogenes / genetics
  • Listeria monocytogenes / physiology*
  • Membrane Proteins / biosynthesis
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism
  • Microfilament Proteins / isolation & purification
  • Microfilament Proteins / physiology*
  • Models, Biological
  • Oocytes / microbiology
  • Oocytes / physiology*
  • Profilins
  • Xenopus laevis


  • Actins
  • Bacterial Proteins
  • Contractile Proteins
  • Membrane Proteins
  • Microfilament Proteins
  • Profilins
  • actA protein, Listeria monocytogenes