The Arp2/3 complex: a multifunctional actin organizer.

The actin-related proteins (Arps) constitute a recently characterized family of proteins, many of which function as members of multiprotein complexes. The discovery that two family members, Arp2 and Arp3, act as multifunctional organizers of actin filaments in all eukaryotes has generated much excitement. Over the past two years, newly discovered properties of the Arp2/3 complex have suggested a central role in the control of actin polymerization. First, it promotes actin assembly on the surface of the motile intracellular pathogen Listeria monocytogenes. Second, it can nucleate and cross-link actin filaments in vitro. Third, it localizes with dynamic actin-rich spots of mammalian cells suggesting a role in protrusion; it is found in cortical actin patches in the budding and fission yeasts where it may control patch movement and cortical actin function. Clearly, the complex has a central role in actin cytoskeletal function and will be the subject of much research in the coming years.

[1]  T D Pollard,et al.  The interaction of Arp2/3 complex with actin: nucleation, high affinity pointed end capping, and formation of branching networks of filaments. , 1998, Proceedings of the National Academy of Sciences of the United States of America.

[2]  K. Gould,et al.  The Schizosaccharomyces pombe cdc3+ gene encodes a profilin essential for cytokinesis , 1994, The Journal of cell biology.

[3]  T. Pollard,et al.  Purification of a cortical complex containing two unconventional actins from Acanthamoeba by affinity chromatography on profilin-agarose , 1994, The Journal of cell biology.

[4]  D. Drubin,et al.  The yeast actin cytoskeleton. , 1994, Current opinion in cell biology.

[5]  D. Helfman,et al.  Identification of act2, an essential gene in the fission yeast Schizosaccharomyces pombe that encodes a protein related to actin. , 1992, Proceedings of the National Academy of Sciences of the United States of America.

[6]  J. Cooper,et al.  Movement of cortical actin patches in yeast , 1996, The Journal of cell biology.

[7]  V. Moreau,et al.  The yeast actin-related protein Arp2p is required for the internalization step of endocytosis. , 1997, Molecular biology of the cell.

[8]  Gary G. Borisy,et al.  Analysis of the Actin–Myosin II System in Fish Epidermal Keratocytes: Mechanism of Cell Body Translocation , 1997, The Journal of cell biology.

[9]  M. Rothkegel,et al.  Profilins as regulators of actin dynamics. , 1997, Biochimica et biophysica acta.

[10]  Laura M. Machesky,et al.  Scar1 and the related Wiskott–Aldrich syndrome protein, WASP, regulate the actin cytoskeleton through the Arp2/3 complex , 1998, Current Biology.

[11]  Timothy J. Mitchison,et al.  Actin polymerization is induced by Arp 2/3 protein complex at the surface of Listeria monocytogenes , 1997, Nature.

[12]  T D Pollard,et al.  Sequences, structural models, and cellular localization of the actin- related proteins Arp2 and Arp3 from Acanthamoeba , 1995, The Journal of cell biology.

[13]  A. Burlingame,et al.  Mammalian actin-related protein 2/3 complex localizes to regions of lamellipodial protrusion and is composed of evolutionarily conserved proteins. , 1997, The Biochemical journal.

[14]  B. Dujon,et al.  The Saccharomyces cerevisiae actin-related protein Arp2 is involved in the actin cytoskeleton , 1996, The Journal of cell biology.

[15]  Walter F. Stafford,et al.  Structure, Subunit Topology, and Actin-binding Activity of the Arp2/3 Complex from Acanthamoeba , 1997, The Journal of cell biology.

[16]  K. Gould,et al.  Fission yeast Sop2p: a novel and evolutionarily conserved protein that interacts with Arp3p and modulates profilin function. , 1996, The EMBO journal.

[17]  T. Mitchison,et al.  Interaction of human Arp2/3 complex and the Listeria monocytogenes ActA protein in actin filament nucleation. , 1998, Science.

[18]  T. Mélèse,et al.  A role for the divergent actin gene, ACT2, in nuclear pore structure and function , 1997, The EMBO journal.

[19]  E. Schwob,et al.  New yeast actin-like gene required late in the cell cycle , 1992, Nature.

[20]  K. Gould,et al.  The Schizosaccharomyces pombe actin‐related protein, Arp3, is a component of the cortical actin cytoskeleton and interacts with profilin. , 1996, The EMBO journal.

[21]  A. DePace,et al.  The Human Arp2/3 Complex Is Composed of Evolutionarily Conserved Subunits and Is Localized to Cellular Regions of Dynamic Actin Filament Assembly , 1997, The Journal of cell biology.

[22]  P. Morandini,et al.  An actin‐related protein from Dictyostelium discoideum is developmentallyregulated and associated with mitochondria , 1995, FEBS letters.

[23]  T. Pollard,et al.  Arp2/3 complex from Acanthamoeba binds profilin and cross-links actin filaments. , 1998, Molecular biology of the cell.