Cell biology - Mechanism of actin-based motility

Spatially controlled polymerization of actin is that the origin of cell mot ility and is responsible for the formation of cellular protrusions Like lam ellipodia. The pathogens Listeria monocytogenes and Shigella flexneri, whic h undergo actin-based propulsion, are acknowledged models of the Leading ed ge of lamellipodia. Actin-based motility of the bacteria or of functionaliz ed microspheres can be reconstituted in vitro from only five pure proteins. Movement results from the regulated site-directed treadmilling of actin fi laments, consistent with observations of actin dynamics in living motile ce lls and with the biochemical properties of the components of the synthetic motility medium.