Similarities between actin polymerization at the leading edges of motile ma
mmalian cells and the motile actin tail of the bacterium Listeria monocytog
enes are centred on the Arp2/3 complex. Eukaryotic cells use multiple pathw
ays to modulate actin polymerization, while Listeria short-circuits these p
athways to produce constitutive actin polymerization.