Amoeboid Locomotion: Evolution of Ideas

• 1950’s-1980’s: Actin-myosin contraction dominates
• 1987: Dicty Myosin II Heavy chain Knock outs; MII not essential
• 1980’s-1990’s: Work on various cells shows that actin polymerization at the leading edge is required; Theriot and Mitchison show that rate of assembly equals the rate of actin polymerization.
• Early 1990’s: Discovery of actin-based movement of Listeria
• 1990’s: ActA in Listeria, actin assembly at bacterial surface pushes bacterium forward
• 1998-1999: Carlier identifies minimum required components for Listeria movements in vitro; list includes Arp 2/3.
• Late 1990’s: Discovery of properties of Arp 2/3
• Late 1990’s: Dendritic nucleation model proposed
• 1999-2000: Borisy and Svitkine- dendritic nucleation in vivo in fish keratocytes (also fibroblasts and Listeria.)