title: Capping protein regulators fine-tune actin assembly dynamics.
abstract: Capping protein (CP) binds the fast growing barbed end of the actin filament and regulates actin assembly by blocking the addition and loss of actin subunits. Recent studies provide new insights into how CP and barbed-end capping are regulated. Filament elongation factors, such as formins and ENA/VASP (enabled/vasodilator-stimulated phosphoprotein), indirectly regulate CP by competing with CP for binding to the barbed end, whereas other molecules, including V-1 and phospholipids, directly bind to CP and sterically block its interaction with the filament. In addition, a diverse and unrelated group of proteins interact with CP through a conserved 'capping protein interaction' (CPI) motif. These proteins, including CARMIL (capping protein, ARP2/3 and myosin I linker), CD2AP (CD2-associated protein) and the WASH (WASP and SCAR homologue) complex subunit FAM21, recruit CP to specific subcellular locations and modulate its actin-capping activity via allosteric effects.
authors.affiliation: Department of Cell Biology and Physiology, Washington University, St. Louis, Missouri 63110, USA.
authors.forename: Marc
authors.initials: M
authors.lastname: Edwards
authors.affiliation: Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
authors.forename: Adam
authors.initials: A
authors.lastname: Zwolak
authors.affiliation: Departments of Biology and Cell Biology, University of Virginia, Charlottesville, Virginia 22904, USA.
authors.forename: Dorothy A
authors.initials: DA
authors.lastname: Schafer
authors.affiliation: Department of Biomedical Engineering and Center for Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, Michigan 48109, USA.
authors.forename: David
authors.initials: D
authors.lastname: Sept
authors.affiliation: Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
authors.forename: Roberto
authors.initials: R
authors.lastname: Dominguez
authors.affiliation: Department of Cell Biology and Physiology, Washington University, St. Louis, Missouri 63110, USA.
authors.forename: John A
authors.initials: JA
authors.lastname: Cooper
mesh_terms: D051344:Actin Capping Proteins / Q000378:metabolism* / Q000502:physiology; D008841:Actin Cytoskeleton / Q000502:physiology*; D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism / Q000502:physiology; D000595:Amino Acid Sequence; D002352:Carrier Proteins / Q000378:metabolism / Q000502:physiology; D003598:Cytoskeletal Proteins / Q000378:metabolism / Q000502:physiology; D004268:DNA-Binding Proteins / Q000378:metabolism* / Q000502:physiology; D006801:Humans; D008840:Microfilament Proteins / Q000378:metabolism / Q000502:physiology; D008958:Models, Molecular; D018129:Phosphatidylinositol Phosphates / Q000737:chemistry; D011485:Protein Binding; D011487:Protein Conformation
chemical_list: D051344:Actin Capping Proteins; D048868:Adaptor Proteins, Signal Transducing; C547525:CARMIL1 protein, human; C114545:CD2-associated protein; D002352:Carrier Proteins; D003598:Cytoskeletal Proteins; D004268:DNA-Binding Proteins; C092744:ENA-VASP proteins; D008840:Microfilament Proteins; D018129:Phosphatidylinositol Phosphates; C549919:WASH protein, human