Interaction of Human Arp2/3 Complex and the Listeria monocytogenes ActA Protein in Actin Filament Nucleation

• DOI: 10.1126/science.281.5373.105
• Publication Date: 2002-07-27T09:43:20Z
• Authors: Matthew D. Welch; Jody Rosenblatt; Justin Skoble; Daniel A. Portnoy; Timothy J. Mitchison
• Keywords: 0301 basic medicine; Cytochalasin D; Cell Membrane; Membrane Proteins; Listeria monocytogenes; Actins; Cytoskeletal Proteins; Kinetics; Microscopy, Electron; 03 medical and health sciences; Biopolymers; Bacterial Proteins; Actin-Related Protein 3; Actin-Related Protein 2; Humans

Actin filament assembly at the cell surface of the pathogenic bacterium Listeria monocytogenes requires the bacterial ActA surface protein and the host cell Arp2/3 complex. Purified Arp2/3 complex accelerated the nucleation of actin polymerization in vitro, but pure ActA had no effect. However, when combined, the Arp2/3 complex and ActA synergistically stimulated the nucleation of actin filaments. This mechanism of activating the host Arp2/3 complex at the L. monocytogenes surface may be similar to the strategy used by cells to control Arp2/3 complex activity and hence the spatial and temporal distribution of actin polymerization.