title: Cellular motility driven by assembly and disassembly of actin filaments.
abstract: Motile cells extend a leading edge by assembling a branched network of actin filaments that produces physical force as the polymers grow beneath the plasma membrane. A core set of proteins including actin, Arp2/3 complex, profilin, capping protein, and ADF/cofilin can reconstitute the process in vitro, and mathematical models of the constituent reactions predict the rate of motion. Signaling pathways converging on WASp/Scar proteins regulate the activity of Arp2/3 complex, which mediates the initiation of new filaments as branches on preexisting filaments. After a brief spurt of growth, capping protein terminates the elongation of the filaments. After filaments have aged by hydrolysis of their bound ATP and dissociation of the gamma phosphate, ADF/cofilin proteins promote debranching and depolymerization. Profilin catalyzes the exchange of ADP for ATP, refilling the pool of ATP-actin monomers bound to profilin, ready for elongation.
authors.affiliation: Department of Cellular, Molecular, and Developmental Biology, Yale University, New Haven, CT 06520, USA. thomas.pollard@yale.edu
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Pollard
authors.forename: Gary G
authors.initials: GG
authors.lastname: Borisy
mesh_terms: D051339:Actin Depolymerizing Factors; D000199:Actins / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D000244:Adenosine Diphosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D002417:Cattle; D002455:Cell Division; D002462:Cell Membrane / Q000378:metabolism; D002465:Cell Movement; D002467:Cell Nucleus / Q000378:metabolism; D018360:Crystallography, X-Ray; D003712:Dendrites / Q000378:metabolism; D015603:Keratinocytes / Q000648:ultrastructure; D008840:Microfilament Proteins / Q000378:metabolism; D008954:Models, Biological; D008958:Models, Molecular; D010710:Phosphates / Q000378:metabolism; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D015398:Signal Transduction
chemical_list: D051339:Actin Depolymerizing Factors; D000199:Actins; D008840:Microfilament Proteins; D010710:Phosphates; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate