The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.

wikigene or wiki gene protein drug chemical gene disease author authorship tracking collaborative publishing evolutionary knowledge reputation system wiki2.0 global collaboration genes proteins drugs chemicals diseases compound
Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)



Gene Review

ACTR3  -  ARP3 actin-related protein 3 homolog (yeast)

Homo sapiens

Synonyms: ARP3, Actin-like protein 3, Actin-related protein 3
Welcome! If you are familiar with the subject of this article, you can contribute to this open access knowledge base by deleting incorrect information, restructuring or completely rewriting any text. Read more.

Disease relevance of ACTR3


High impact information on ACTR3

  • We predict that WASp/Scar proteins activate Arp2/3 complex by bringing Arp2 into proximity with Arp3 for nucleation of a branch on the side of a preexisting actin filament [3].
  • ATP hydrolysis by Arp2, and possibly Arp3, is essential for efficient y-branch dissociation in vitro [4].
  • Our data suggest a bivalent attachment of WASp to Arp3 (within peptides 162-191 and 318-329) and Arp2 (within peptides 66-80 and 87-97) [5].
  • The Arp2/3 complex, a seven-subunit protein complex containing two actin-related proteins, Arp2 and Arp3, initiates formation of actin filament networks in response to intracellular signals [6].
  • Binding of N-WASP WA increases the affinity of both Arp2 and Arp3 for ATP but does not alter the stoichiometry of nucleotides bound in the presence of saturating concentrations of ATP [6].

Biological context of ACTR3

  • A tccP mutant did not affect Tir translocation and focusing but failed to recruit alpha-actinin, Arp3, N-WASP and actin to the site of bacterial adhesion [7].
  • Sequence analysis revealed that this novel gene has an open reading frame of 210 amino acid residues showing 89% amino acid identity with human Arp3, which is one of the actin-related proteins [8].
  • Partial amino acid sequences of the peptides derived from the 45K and 40K proteins showed that these proteins are homologous to Arp3 and Arp2 subfamilies of actin-related proteins, respectively [9].
  • Consistent with a common binding site on Arp3, a saturating concentration of VCA abolished binding of cortactin to Arp2/3 complex [10].
  • Surprisingly, Arp3 organized into similar adhesion contacts in cells expressing wild-type beta(3) but not in those expressing a nonphosphorylatable mutant of beta(3), suggesting that beta(3) phosphorylation is required for sequestration of Arp3 to adhesion complexes [11].

Anatomical context of ACTR3

  • The Arp2/3 complex, a stable assembly of two actin-related proteins (Arp2 and Arp3) with five other subunits, caps the pointed end of actin filaments and nucleates actin polymerization with low efficiency [12].
  • BACKGROUND: The actin-related proteins Arp2 and Arp3 are part of a seven-protein complex which is localized in the lamellipodia of a variety of cell types, and in actin-rich spots of unknown function [13].
  • Arp2 and Arp3 showed identical expression patterns, and both were expressed in the stromal cells around neoplastic tubules or glands and in the tumor cells themselves [2].
  • Suppression of actin stress fiber formation by an inhibitor to Rho kinase disrupted Arp3 organization while prolonging beta(3) phosphorylation throughout the adhesion time course [11].
  • Beta 3 integrin phosphorylation is essential for Arp3 organization into leukocyte alpha V beta 3-vitronectin adhesion contacts [11].

Associations of ACTR3 with chemical compounds

  • We show here that adenosine nucleotides bind with micromolar affinity to both Arp2 and Arp3 and that hydrolyzable ATP is required for actin nucleation activity [6].

Physical interactions of ACTR3

  • We propose that ActA and endogenous WASP family proteins promote Arp2/3-dependent nucleation by similar mechanisms and require simultaneous binding of Arp2 and Arp3 [14].

Other interactions of ACTR3


Analytical, diagnostic and therapeutic context of ACTR3

  • MATERIALS AND METHODS: Western blot analysis was used to determine levels of Arp2 and Arp3, two components of the Arp2/3 complex in osteoclast-like cells [16].
  • In addition, ectopically expressed full-length GFP-N-WASP was recruited by S. flexneri but not R. rickettsii, and Arp3 was detected by indirect immunofluorescence in S. flexneri actin tails but not within R. rickettsii actin tails [17].
  • Most Arp3 protein is found in a multi-protein complex; we purified this complex and determined the sequences of each of the protein subunits using a high-accuracy mass peptide-mapping technique [18].
  • Confocal microscopy showed Arp3 accumulation in AGS cells infected with wild-type H. pylori, but not in response to infection with the cagE mutant [19].


  1. Differential roles for actin polymerization and a myosin II motor in assembly of the epithelial apical junctional complex. Ivanov, A.I., Hunt, D., Utech, M., Nusrat, A., Parkos, C.A. Mol. Biol. Cell (2005) [Pubmed]
  2. Involvement of Arp2/3 complex in the process of colorectal carcinogenesis. Otsubo, T., Iwaya, K., Mukai, Y., Mizokami, Y., Serizawa, H., Matsuoka, T., Mukai, K. Mod. Pathol. (2004) [Pubmed]
  3. Crystal structure of Arp2/3 complex. Robinson, R.C., Turbedsky, K., Kaiser, D.A., Marchand, J.B., Higgs, H.N., Choe, S., Pollard, T.D. Science (2001) [Pubmed]
  4. Arp2/3 ATP hydrolysis-catalysed branch dissociation is critical for endocytic force generation. Martin, A.C., Welch, M.D., Drubin, D.G. Nat. Cell Biol. (2006) [Pubmed]
  5. Visualizing Arp2/3 complex activation mediated by binding of ATP and WASp using structural mass spectrometry. Kiselar, J.G., Mahaffy, R., Pollard, T.D., Almo, S.C., Chance, M.R. Proc. Natl. Acad. Sci. U.S.A. (2007) [Pubmed]
  6. Arp2/3 complex requires hydrolyzable ATP for nucleation of new actin filaments. Dayel, M.J., Holleran, E.A., Mullins, R.D. Proc. Natl. Acad. Sci. U.S.A. (2001) [Pubmed]
  7. TccP is an enterohaemorrhagic Escherichia coli O157:H7 type III effector protein that couples Tir to the actin-cytoskeleton. Garmendia, J., Phillips, A.D., Carlier, M.F., Chong, Y., Schüller, S., Marches, O., Dahan, S., Oswald, E., Shaw, R.K., Knutton, S., Frankel, G. Cell. Microbiol. (2004) [Pubmed]
  8. Isolation of a novel actin-related gene expressed in low-metastatic PC-14 human lung adenocarcinoma. Shindo-Okada, N., Shimizu, K. Biochem. Biophys. Res. Commun. (2001) [Pubmed]
  9. Identification of actin-binding proteins from sea urchin eggs by F-actin affinity column chromatography. Terasaki, A.G., Ohnuma, M., Mabuchi, I. J. Biochem. (1997) [Pubmed]
  10. Interaction of cortactin and N-WASp with Arp2/3 complex. Weaver, A.M., Heuser, J.E., Karginov, A.V., Lee, W.L., Parsons, J.T., Cooper, J.A. Curr. Biol. (2002) [Pubmed]
  11. Beta 3 integrin phosphorylation is essential for Arp3 organization into leukocyte alpha V beta 3-vitronectin adhesion contacts. Chandhoke, S.K., Williams, M., Schaefer, E., Zorn, L., Blystone, S.D. J. Cell. Sci. (2004) [Pubmed]
  12. Scar, a WASp-related protein, activates nucleation of actin filaments by the Arp2/3 complex. Machesky, L.M., Mullins, R.D., Higgs, H.N., Kaiser, D.A., Blanchoin, L., May, R.C., Hall, M.E., Pollard, T.D. Proc. Natl. Acad. Sci. U.S.A. (1999) [Pubmed]
  13. Scar1 and the related Wiskott-Aldrich syndrome protein, WASP, regulate the actin cytoskeleton through the Arp2/3 complex. Machesky, L.M., Insall, R.H. Curr. Biol. (1998) [Pubmed]
  14. Activation of the Arp2/3 complex by the Listeria acta protein. Acta binds two actin monomers and three subunits of the Arp2/3 complex. Zalevsky, J., Grigorova, I., Mullins, R.D. J. Biol. Chem. (2001) [Pubmed]
  15. {beta}1 and {beta}3 Integrins Cooperate to Induce Syndecan-4-Containing Cross-linked Actin Networks in Human Trabecular Meshwork Cells. Filla, M.S., Woods, A., Kaufman, P.L., Peters, D.M. Invest. Ophthalmol. Vis. Sci. (2006) [Pubmed]
  16. Actin-related protein 2/3 complex is required for actin ring formation. Hurst, I.R., Zuo, J., Jiang, J., Holliday, L.S. J. Bone Miner. Res. (2004) [Pubmed]
  17. Rickettsial actin-based motility: behavior and involvement of cytoskeletal regulators. Heinzen, R.A. Ann. N. Y. Acad. Sci. (2003) [Pubmed]
  18. The complex containing actin-related proteins Arp2 and Arp3 is required for the motility and integrity of yeast actin patches. Winter, D., Podtelejnikov, A.V., Mann, M., Li, R. Curr. Biol. (1997) [Pubmed]
  19. Cytoskeletal rearrangements in gastric epithelial cells in response to Helicobacter pylori infection. Su, B., Ceponis, P.J., Sherman, P.M. J. Med. Microbiol. (2003) [Pubmed]
WikiGenes - Universities