ACTIN-BASED BACTERIAL MOTILITY - TOWARDS A DEFINITION OF THE MINIMAL REQUIREMENTS

At the border line between microbiology and cell biology, the spectacu lar capacity of some intracellular bacterial pathogens, including List eria monocytogenes, Shigella flexneri and several Rickettsias, to use actin polymerization as a driving force for intracellular movement, ce ll-to-cell spreading and dissemination within the infected tissue is b eing increasingly studied. Now that it is possible to manipulate the b acterial surface proteins involved in this process - Act4 of L. monocy togenes and IcsA of S. flexneri - these bacterial systems are providin g experimental models in which to investigate the role of actin filame nt dynamics in cell motility.