Key Points
-
The plasma membrane of many motile cells undergoes highly regulated protrusions and invaginations that support the formation of podosomes, invadopodia and circular dorsal ruffles/waves. Although similar in appearance and in their formation — which is mediated by a highly conserved actin–membrane apparatus — these transient surface membrane distortions are distinct. Their function is to help the cell as it migrates through, attaches to, and invades the extracellular matrix.
-
Invadopodia are convolutions and extensions of the ventral plasma membrane that contacts the substratum. These structures represent specific sites where degradation of the underlying matrix occurs, and might also be secretory sites to which nascent protease-containing carriers are targeted for release. Invadopodia are prominent in cells that actively migrate and invade surrounding tissues, such as metastatic tumour cells.
-
Podosomes, which are less well defined than invadopodia, are also formed along the cell base. These structures share many components and features with invadopodia and might represent a modification of invadopodia in cells that are cultured on an artificial substrate such as glass.
-
Circular dorsal ruffles/waves are formed on the dorsal surface of cells after stimulation of receptor tyrosine kinases including the epidermal growth factor receptor or the platelet-derived growth factor receptor. Circular dorsal ruffles/waves use many of the same components as invadopodia and podosomes, but are transient, appear to reorganize the surrounding actin cytoskeleton, and might have an endocytic function as opposed to a secretory one.
Abstract
The plasma membrane of many motile cells undergoes highly regulated protrusions and invaginations that support the formation of podosomes, invadopodia and circular dorsal ruffles. Although they are similar in appearance and in their formation — which is mediated by a highly conserved actin–membrane apparatus — these transient surface membrane distortions are distinct. Their function is to help the cell as it migrates, attaches and invades.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 12 print issues and online access
206,07 € per year
only 17,17 € per issue
Buy this article
- Purchase on SpringerLink
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout





Similar content being viewed by others
References
Linder, S. & Aepfelbacher, M. Podosomes: adhesion hot-spots of invasive cells. Trends Cell Biol. 13, 376–385 (2003).
McNiven, M. A., Baldassarre, M. & Buccione, R. The role of dynamin in the assembly and function of podosomes and invadopodia. Front. Biosci. 9, 1944–1953 (2004).
Tarone, G., Cirillo, D., Giancotti, F. G., Comoglio, P. M. & Marchisio, P. C. Rous sarcoma virus-transformed fibroblasts adhere primarily at discrete protrusions of the ventral membrane called podosomes. Exp. Cell Res. 159, 141–157 (1985).
David-Pfeuty, T. & Singer, S. J. Altered distributions of the cytoskeletal proteins vinculin and α-actinin in cultured fibroblasts transformed by Rous sarcoma virus. Proc. Natl Acad. Sci. USA 77, 6687–6691 (1980).
Marchisio, P. C. et al. Cell–substratum interaction of cultured avian osteoclasts is mediated by specific adhesion structures. J. Cell Biol. 99, 1696–1705 (1984). Provides one of the first detailed descriptions of podosomal structures in a non-transformed cell line, namely osteoclasts.
Marchisio, P. C., Cirillo, D., Teti, A., Zambonin-Zallone, A. & Tarone, G. Rous sarcoma virus-transformed fibroblasts and cells of monocytic origin display a peculiar dot-like organization of cytoskeletal proteins involved in microfilament-membrane interactions. Exp. Cell Res. 169, 202–214 (1987).
Spinardi, L. et al. A dynamic podosome-like structure of epithelial cells. Exp. Cell Res. 295, 360–374 (2004).
Marchisio, P. C. et al. Vinculin, talin, and integrins are localized at specific adhesion sites of malignant B lymphocytes. Blood 72, 830–833 (1988).
Stickel, S. K. & Wang, Y. L. α-actinin-containing aggregates in transformed cells are highly dynamic structures. J. Cell Biol. 104, 1521–1526 (1987).
Ochoa, G. -C. et al. A functional link between dynamin and the actin cytoskeleton at podosomes. J. Cell Biol. 150, 377–389 (2000). Pietro de Camilli and colleagues provide a new location and putative function for dynamin-2 at podosomes in v-Src-transformed cells and osteoclasts.
Gaidano, G. et al. Integrin distribution and cytoskeleton organization in normal and malignant monocytes. Leukemia 4, 682–687 (1990).
Shaw, L. M., Messier, J. M. & Mercurio, A. M. The activation dependent adhesion of macrophages to laminin involves cytoskeletal anchoring and phosphorylation of the α6β1 integrin. J. Cell Biol. 110, 2167–2174 (1990).
Gimona, M., Kaverina, I., Resch, G. P., Vignal, E. & Burgstaller, G. Calponin repeats regulate actin filament stability and formation of podosomes in smooth muscle cells. Mol. Biol. Cell 14, 2482–2491 (2003).
Linder, S., Nelson, D., Weiss, M. & Aepfelbacher, M. Wiskott–Aldrich syndrome protein regulates podosomes in primary human macrophages. Proc. Natl Acad. Sci. USA 96, 9648–9653 (1999). In this study WASP was, for the first time, directly implicated in podosome assembly. Further, macrophages from Wiskott–Aldrich syndrome patients (expressing defective WASP forms) were shown to completely lack the ability to form podosomes.
Zicha, D. et al. Chemotaxis of macrophages is abolished in the Wiskott–Aldrich syndrome. Br. J. Haematol. 101, 659–665 (1998).
McNiven, M. A. et al. Regulated interactions between dynamin and the actin-binding protein cortactin modulate cell shape. J. Cell Biol. 151, 187–198 (2000).
Orth, J. D. & McNiven, M. A. Dynamin at the actin–membrane interface. Curr. Opin. Cell Biol. 15, 1–9 (2003).
Lee, E. & De Camilli, P. Dynamin at actin tails. Proc. Natl Acad. Sci. USA 99, 161–166 (2002).
Chen, W. T. Proteolytic activity of specialized surface protrusions formed at rosette contact sites of transformed cells. J. Exp. Zool. 251, 167–185 (1989). The first study to describe (and term as invadopodia) the membrane protrusions of the ventral surface of Rous sarcoma virus (RSV)-transformed cells as specialized structural entities directly involved in the local degradation of the ECM.
Mueller, S. C. & Chen, W. T. Cellular invasion into matrix beads: localization of β1 integrins and fibronectin to the invadopodia. J. Cell Sci. 99, 213–225 (1991).
Bowden, E. T., Barth, M., Thomas, D., Glazer, R. I. & Mueller, S. C. An invasion-related complex of cortactin, paxillin and PKCμ associates with invadopodia at sites of extracellular matrix degradation. Oncogene 18, 4440–4449 (1999). A new function for cortactin was found at invadopodia in a breast cancer cell line. In addition, cortactin was found in a complex with paxillin and protein kinase Cμ in an invadopodia-enriched membrane preparation.
Polishchuk, R. S. et al. Correlative light-electron microscopy reveals the tubular-saccular ultrastructure of carriers operating between Golgi apparatus and plasma membrane. J. Cell Biol. 148, 45–58 (2000).
Baldassarre, M. et al. Dynamin participates in focal extracellular matrix degradation by invasive cells. Mol. Biol. Cell 14, 1074–1084 (2003). Reports a new function and location for dynamin-2 at invadopodia where it is required for ECM degradation. Also provides a detailed ultrastructural analysis of individual invadopodial complexes and immuno-electron localization of dynamin-2 to invadopodial tips that extend into the ECM.
Basbaum, C. B. & Werb, Z. Focalized proteolysis: spatial and temporal regulation of extracellular matrix degradation at the cell surface. Curr. Opin. Cell Biol. 8, 731–738 (1996).
Nakahara, H. et al. Activation of β1 integrin signaling stimulates tyrosine phosphorylation of p190RhoGAP and membrane-protrusive activities at invadopodia. J. Biol. Chem. 273, 9–12 (1998).
Mizutani, K., Miki, H., He, H., Maruta, H. & Takenawa, T. Essential role of neural Wiskott–Aldrich syndrome protein in podosome formation and degradation of extracellular matrix in src-transformed fibroblasts. Cancer Res. 62, 669–674 (2002).
Egeblad, M. & Werb, Z. New functions for the matrix metalloproteinases in cancer progression. Nature Rev. Cancer 2, 161–174 (2002).
Seiki, M. Membrane-type 1 matrix metalloproteinase: a key enzyme for tumor invasion. Cancer Lett. 194, 1–11 (2003).
Holmbeck, K. et al. MT1-MMP-deficient mice develop dwarfism, osteopenia, arthritis, and connective tissue disease due to inadequate collagen turnover. Cell 99, 81–92 (1999).
Hotary, K., Allen, E., Punturieri, A., Yana, I. & Weiss, S. J. Regulation of cell invasion and morphogenesis in a three-dimensional type I collagen matrix by membrane-type matrix metalloproteinases 1, 2, and 3. J. Cell Biol. 149, 1309–1323 (2000).
Sweitzer, S. M. & Hinshaw, J. E. Dynamin undergoes a GTP-dependent conformational change causing vesiculation. Cell 93, 1021–1029 (1998).
Takei, K. et al. Coated intermediates of clathrin-mediated endocytosis generated by brain cytosol on protein-free liposomes. Cell 94, 131–141 (1998).
Zhang, P. & Hinshaw, J. E. Three-dimensional reconstruction of dynamin in the constricted state. Nature Cell Biol. 3, 922–926 (2001).
Marks, B. et al. GTPase activity of dynamin and resulting conformation change are essential for endocytosis. Nature 410, 231–235 (2001).
Takei, K., Slepnev, V. I., Haucke, V. & De Camilli, P. Functional partnership between amphiphysin and dynamin in clathrin-mediated endocytosis. Nature Cell Biol. 1, 33–39 (1999).
Merrifield, C. J., Feldman, M. E., Wan, L. & Almers, W. Imaging actin and dynamin recruitment during invagination of single clathrin-coated pits. Nature Cell Biol. 4, 691–698 (2002).
Cao, H. et al. Cortactin is a component of clathrin-coated pits and participates in receptor-mediated endocytosis. Mol. Cell Biol. 23, 2162–2170 (2003).
Kreitzer, G., Marmorstein, A., Okamoto, P., Vallee, R. & Rodriguez-Boulin, E. Kinesin and dynamin are required for post-Golgi transport of a plasma membrane protein. Nature Cell Biol. 2, 125–127 (2000).
Cao, H., Thompson, H. M., Krueger, E. W. & McNiven, M. A. Disruption of Golgi structure and function in mammalian cells expressing a mutant dynamin. J. Cell Sci. 113, 1993–2002 (2000).
Krueger, E. W., Orth, J. D., Cao, H. & McNiven, M. A. A dynamin–cortactin–Arp2/3 complex mediates actin reorganization in growth factor-stimulated cells. Mol. Biol. Cell 14, 1085–1096 (2003). The first identification of dynamin-2, cortactin, N-WASP and the Arp2/3 complex at circular dorsal ruffles/waves. This study was also the first to quantify actin remodelling at these structures.
Orth, J. D., Krueger, E. W., Cao, H. & McNiven, M. A. The large GTPase dynamin regulates actin comet formation and movement in living cells. Proc. Natl Acad. Sci. USA 99, 167–172 (2002).
Zambonin-Zallone, A., Teti, A., Carano, A. & Marchisio, P. C. The distribution of podosomes in osteoclasts cultured on bone laminae: effect of retinol. J. Bone Miner. Res. 3, 517–523 (1988).
Lakkakorpi, P., Tuukkanen, J., Hentunen, T., Jarvelin, K. & Vaananen, K. Organization of osteoclast microfilaments during the attachment to bone surface in vitro. J. Bone Miner. Res. 4, 817–825 (1989).
Kanehisa, J. et al. A band of F-actin containing podosomes is involved in bone resorption by osteoclasts. Bone 11, 287–293 (1990).
Destaing, O., Saltel, F., Geminard, J. C., Jurdic, P. & Bard, F. Podosomes display actin turnover and dynamic self-organization in osteoclasts expressing actin–green fluorescent protein. Mol. Biol. Cell 14, 407–416 (2003).
Teti, A., Colucci, S., Grano, M., Argentino, L. & Zambonin-Zallone, A. Protein kinase C affects microfilaments, bone resorption, and [Ca2+]o sensing in cultured osteoclasts. Am. J. Physiol. 263, C130–C139 (1992).
Duong, L. T. et al. PYK2 in osteoclasts is an adhesion kinase, localized in the sealing zone, activated by ligation of αvβ3 integrin, and phosphorylated by src kinase. J. Clin. Invest. 102, 881–892 (1998).
Sato, T. et al. Identification of the membrane-type matrix metalloproteinase MT1-MMP in osteoclasts. J. Cell Sci. 110, 589–596 (1997).
Coopman, P. J., Thomas, D. M., Gehlsen, K. R. & Mueller, S. C. Integrin α3β1 participates in the phagocytosis of extracellular matrix molecules by human breast cancer cells. Mol. Biol. Cell 7, 1789–1804 (1996).
Mellstrom, K. et al. The effect of platelet-derived growth factor on morphology and motility of human glial cells. J. Muscle Res. Cell Motil. 4, 589–609 (1983).
Dowrick, P., Kenworthy, P., McCann, B. & Warn, R. Circular ruffle formation and closure lead to macropinocytosis in hepatocyte growth factor/scatter factor-treated cells. Eur. J. Cell Biol. 61, 44–53 (1993).
Chinkers, M., McKanna, J. A. & Cohen, S. Rapid induction of morphological changes in human carcinoma cells A-431 by epidermal growth factors. J. Cell Biol. 83, 260–265 (1979).
Mellstrom, K., Heldin, C. H. & Westermark, B. Induction of circular membrane ruffling on human fibroblasts by platelet-derived growth factor. Exp. Cell Res. 177, 347–359 (1988).
Schliwa, M., Nakamura, T., Porter, K. R. & Euteneuer, U. A tumor promoter induces rapid and coordinated reorganization of actin and vinculin in cultured cells. J. Cell Biol. 99, 1045–1059 (1984).
Kitano, Y., Okada, N. & Adachi, J. TPA-induced alteration of actin organization in cultured human keratinocytes. Exp. Cell Res. 167, 369–375 (1986).
Hedberg, K. M., Bengtsson, T., Safiejko-Mroczka, B., Bell, P. B. & Lindroth, M. PDGF and neomycin induce similar changes in the actin cytoskeleton in human fibroblasts. Cell Motil. Cytoskeleton 24, 139–149 (1993).
Safiejko-Mroczka, B. & Bell, P. B. Jr. Distribution of cytoskeletal proteins in neomycin-induced protrusions of human fibroblasts. Exp. Cell Res. 242, 495–514 (1998).
Bereiter-Hahn, J., Strohmeier, R., Kunzenbacher, I., Beck, K. & Voth, M. Locomotion of Xenopus epidermis cells in primary culture. J. Cell Sci. 52, 289–311 (1981).
Soranno, T. & Bell, E. Cytostructural dynamics of spreading and translocating cells. J. Cell Biol. 95, 127–136 (1982).
Marchisio, P. C., Capasso, O., Nitsch, L., Cancedda, R. & Gionti, E. Cytoskeleton and adhesion patterns of cultured chick embryo chondrocytes during cell spreading and Rous sarcoma virus transformation. Exp. Cell Res. 151, 332–343 (1984).
Dharmawardhane, S., Sanders, L. C., Martin, S. S., Daniels, R. H. & Bokoch, G. M. Localization of p21-activated kinase 1 (PAK1) to pinocytic vesicles and cortical actin structures in stimulated cells. J. Cell Biol. 138, 1265–1278 (1997).
Borisy, G. G. & Svitkina, T. M. Actin machinery: pushing the envelope. Curr. Opin. Cell Biol. 12, 104–112 (2000).
Nister, M. et al. A glioma-derived PDGF A chain homodimer has different functional activities from a PDGF AB heterodimer purified from human platelets. Cell 52, 791–799 (1988).
Hammacher, A., Mellstrom, K., Heldin, C. H. & Westermark, B. Isoform-specific induction of actin reorganization by platelet-derived growth factor suggests that the functionally active receptor is a dimer. EMBO J. 8, 2489–2495 (1989).
Eriksson, A., Siegbahn, A., Westermark, B., Heldin, C. H. & Claesson-Welsh, L. PDGF α- and β-receptors activate unique and common signal transduction pathways. EMBO J. 11, 543–550 (1992).
Arvidsson, A. K., Heldin, C. H. & Claesson-Welsh, L. Transduction of circular membrane ruffling by the platelet-derived growth factor β-receptor is dependent on its kinase insert. Cell Growth Differ. 3, 881–887 (1992).
Westphal, R. S., Soderling, S. H., Alto, N. M., Langeberg, L. K. & Scott, J. D. Scar/WAVE-1, a Wiskott–Aldrich syndrome protein, assembles an actin-associated multi-kinase scaffold. EMBO J. 19, 4589–4600 (2000).
Lanzetti, L., Palamidessi, A., Areces, L., Scita, G. & Di Fiore, P. P. Rab5 is a signalling GTPase involved in actin remodeling by receptor tyrosine kinases. Nature 429, 309–314 (2004). Provided the first link between Rab5 and remodelling of the actin cytoskeleton in cells at the site of circular dorsal ruffles/waves. Also found that the Rab5 GAP RN-tre binds directly to F-actin and associates with actinin-4.
Orth, J. D., Krueger, E. W. & McNiven, M. A. A dynamin–cortactin–N-WASp complex mediates the sequestration and macropinocytic internalization of the EGF-receptor via dorsal ruffles/waves. Mol. Biol. Cell 14 (Suppl. 1), A465 (2003).
Ballestrem, C., Wehrle-Haller, B. & Imhof, B. A. Actin dynamics in living mammalian cells. J. Cell Sci. 111, 1649–1658 (1998).
Suetsugu, S., Yamazaki, D., Kurisu, S. & Takenawa, T. Differential roles of WAVE1 and WAVE2 in dorsal and peripheral ruffle formation for fibroblast cell migration. Dev. Cell 5, 595–609 (2003). Suetsugu et al . were the first to show, using knockout-mouse technology, new functions for the two WAVE forms. WAVE1 is required for formation of circular dorsal ruffles/waves whereas WAVE2 is required for conventional macropinocytosis. Therefore, it was concluded that circular dorsal ruffles/waves probably do not function in macropinocytosis.
Warn, R., Brown, D., Dowrick, P., Prescott, A. & Warn, A. Cytoskeletal changes associated with cell motility. Symp. Soc. Exp. Biol. 47, 325–338 (1993).
Orth, J. D., Gray, N. W., Thompson, H. M. & McNiven, M. A. in Cell Motility: From Molecules to Organisms (eds Ridley, A. J., Clark, P. & Peckham, M.) 189–201 (John Wiley & Sons, Ltd., Hoboeken, USA, 2003).
Miki, H., Miura, K. & Takenawa, T. N-WASP, a novel actin-depolymerizing protein, regulates the cortical cytoskeletal rearrangement in a PIP2-dependent manner downstream of tyrosine kinases. EMBO J. 15, 5326–5335 (1996).
Mullins, R. D. How WASP-family proteins and the Arp2/3 complex convert intracellular signals into cytoskeletal structures. Curr. Opin. Cell Biol. 12, 91–96 (2000).
Anton, I. M. et al. WIP participates in actin reorganization and ruffle formation induced by PDGF. J. Cell Sci. 116, 2443–2451 (2003).
Uruno, T. et al. Activation of Arp2/3 complex-mediated actin polymerization by cortactin. Nature Cell Biol. 3, 259–265 (2001).
Weaver, A. M. et al. Cortactin promotes and stabilizes Arp2/3-induced actin filament network formation. Curr. Biol. 11, 370–374 (2001).
Wu, H. & Parsons, J. T. Cortactin, an 80/85-kilodalton pp60src substrate, is a filamentous actin-binding protein enriched in the cell cortex. J. Cell Biol. 120, 1417–1426 (1993).
Weed, S. A. & Parsons, J. T. Cortactin: coupling membrane dynamics to cortical actin assembly. Oncogene 20, 6418–6434 (2001).
Schafer, D. A. et al. Dynamin2 and cortactin regulate actin assembly and filament organization. Curr. Biol. 12, 1852–1857 (2002).
Dharmawardhane, S. et al. Regulation of macropinocytosis by p21-activated kinase-1. Mol. Biol. Cell 11, 3341–3352 (2000).
Vadlamudi, R. K., Li, F., Barnes, C. J., Bagheri-Yarmand, R. & Kumar, R. p41Arc subunit of human Arp2/3 complex is a p21-activated kinase-1-interacting substrate. EMBO Rep. 5, 154–160 (2004).
Papakonstanti, E. A. & Stournaras, C. Association of PI-3 kinase with PAK1 leads to actin phosphorylation and cytoskeletal reorganization. Mol. Biol. Cell 13, 2946–2962 (2002).
Plattner, R., Kadlec, L., DeMali, K. A., Kazlauskas, A. & Pendergast, A. M. c-Abl is activated by growth factors and Src family kinases and has a role in the cellular response to PDGF. Genes Dev. 13, 2400–2411 (1999). Plattner et al . used mouse-embryo fibroblasts from an Abl -knockout mouse and showed for the first time that Abl is activated downstream of PDGF and is required for maximal formation of PDGF-induced circular dorsal ruffles/waves.
Diviani, D. & Scott, J. D. AKAP signaling complexes at the cytoskeleton. J. Cell Sci. 114, 1431–1437 (2001).
Van Etten, R. A. et al. The COOH terminus of the c-Abl tyrosine kinase contains distinct F- and G-actin binding domains with bundling activity. J. Cell Biol. 124, 325–340 (1994).
Van Etten, R. A., Jackson, P. & Baltimore, D. The mouse type IV c-abl gene product is a nuclear protein, and activation of transforming ability is associated with cytoplasmic localization. Cell 58, 669–678 (1989).
McWhirter, J. R. & Wang, J. Y. Activation of tyrosinase kinase and microfilament-binding functions of c-abl by bcr sequences in bcr/abl fusion proteins. Mol. Cell Biol. 11, 1553–1565 (1991).
Woodring, P. J., Hunter, T. & Wang, J. Y. Regulation of F-actin-dependent processes by the Abl family of tyrosine kinases. J. Cell Sci. 116, 2613–2626 (2003).
Sini, P., Cannas, A., Koleske, A. J., Di Fiore, P. P. & Scita, G. Abl-dependent tyrosine phosphorylation of Sos-1 mediates growth-factor-induced Rac activation. Nature Cell Biol. 6, 268–274 (2004).
Suetsugu, S. et al. Sustained activation of N-WASP through phosphorylation is essential for neurite extension. Dev. Cell 3, 645–658 (2002).
Cory, G. O., Garg, R., Cramer, R. & Ridley, A. J. Phosphorylation of tyrosine 291 enhances the ability of WASp to stimulate actin polymerization and filopodium formation. Wiskott–Aldrich syndrome protein. J. Biol. Chem 277, 45115–45121 (2002).
Cory, G. O., Cramer, R., Blanchoin, L. & Ridley, A. J. Phosphorylation of the WASP-VCA domain increases its affinity for the Arp2/3 complex and enhances actin polymerization by WASP. Mol. Cell 11, 1229–1239 (2003).
Martinez-Quiles, N., Ho, H. H., Kirschner, M. W., Ramesh, N. & Geha, R. S. Erk/Src phosphorylation of cortactin acts as a switch on-switch off mechanism that controls its ability to activate N-WASp. Mol. Cell. Biol. 24, 5269–5280 (2004).
Wymann, M. & Arcaro, A. Platelet-derived growth factor-induced phosphatidylinositol 3-kinase activation mediates actin rearrangements in fibroblasts. Biochem J. 298, 517–520 (1994).
Hooshmand-Rad, R. et al. Involvement of phosphatidylinositide 3′-kinase and Rac in platelet-derived growth factor-induced actin reorganization and chemotaxis. Exp. Cell Res. 234, 434–441 (1997).
Provenzano, C. et al. Eps8, a tyrosine kinase substrate, is recruited to the cell cortex and dynamic F-actin upon cytoskeleton remodeling. Exp. Cell Res. 186–200 (1998).
Innocenti, M. et al. Phosphoinositide 3-kinase activates Rac by entering in a complex with Eps8, Abi1, and Sos-1. J. Cell Biol. 160, 17–23 (2003).
Offenhauser, N. et al. The eps8 family of proteins links growth factor stimulation to actin reorganization generating functional redundancy in the Ras/Rac pathway. Mol. Biol. Cell 15, 91–98 (2004).
Shinohara, M. et al. SWAP-70 is a guanine-nucleotide-exchange factor that mediates signalling of membrane ruffling. Nature 416, 759–763 (2002).
Jackson, T. R. et al. ACAPs are Arf6 GTPase-activating proteins that function in the cell periphery. J. Cell Biol. 151, 627–638 (2000).
Randazzo, P. A. et al. The Arf GTPase-activating protein ASAP1 regulates the actin cytoskeleton. Proc. Natl Acad. Sci. USA 97, 4011–4016 (2000).
Acknowledgements
Work in the R.B. laboratory is supported by the Italian Association for Cancer Research (AIRC, Milano, Italy). Work in the M.A.M. laboratory is supported by funding from the National Institutes of Health and Mayo Foundation. We thank A. Teti and M. Baldassarre for insightful discussions and K. Simmons for help and editorial advice during the preparation of this review.
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Competing interests
The authors declare no competing financial interests.
Supplementary information
Glossary
- LAMELLIPODIA
-
Broad, flat protrusions at the leading edge of a moving cell that are enriched with a branched network of actin filaments.
- FILOPODIA
-
Thin cellular processes containing long, unbranched, parallel bundles of actin filaments.
- PHAGOCYTIC CUP
-
A cup-like extension of peripheral membrane and cytoplasm that partially encircles foreign particles or bacteria during the early stages of the phagocytic process.
- LEADING EDGE
-
The thin margin of a lamellipodium spanning the area of the cell from the plasma membrane to about 1 μm back into the lamellipodium.
- Arp2/3 COMPLEX
-
A complex that consists of two actin-related proteins, Arp2 and Arp3, along with five smaller proteins. When activated, the Arp2/3 complex binds to the side of an existing actin filament and nucleates the assembly of a new actin filament. The resulting branch structure is Y-shaped.
- RHO-FAMILY GTPases
-
Ras-related small GTPases involved in controlling the polymerization of actin.
- EXTRACELLULAR MATRIX
-
(ECM). The complex, multi-molecular material that surrounds cells. The ECM comprises a scaffold on which tissues are organized, it provides cellular microenvironments and it regulates a variety of cellular functions.
- MACROPINOCYTOSIS
-
An actin-dependent process by which cells engulf large volumes of fluids.
- FOCAL ADHESION
-
A cell-to-substrate adhesion structure that anchors the ends of actin microfilaments (stress fibres) and mediates strong attachment to substrates.
- STRESS FIBRES
-
Also termed 'actin-microfilament bundles', these are bundles of parallel filaments that contain F-actin and other contractile molecules, and often stretch between cell attachments as if under stress.
- MONOCYTE
-
Large leukocytes with a horseshoe-shaped nucleus. They derive from pluripotent stem cells and become phagocytic macrophages when they enter tissues.
- OSTEOCLAST
-
A mesenchymal cell that can differentiate into a bone-degrading cell.
- MACROPHAGE
-
Any cell of the mononuclear-phagocyte system that is characterized by its ability to phagocytose foreign particulate and colloidal material.
- DOMINANT-NEGATIVE
-
A defective protein that retains interaction capabilities and so distorts or competes with normal proteins.
- SH3 DOMAIN
-
(Src-homology-3). A protein sequence of ∼50 amino acids that recognizes and binds sequences that are rich in proline.
- CLATHRIN
-
The main component of the coat that is associated with clathrin-coated vesicles, which are involved in membrane transport both in the endocytic and biosynthetic pathways.
- ADAPTOR PROTEINS
-
Proteins that augment cellular responses by recruiting other proteins to a complex. They usually contain several protein–protein interaction domains.
- METALLOPROTEINASE
-
A proteinase that has a metal ion at its active site.
- ACTIN COMET TAIL
-
An actin tail at one end of an endosome that propels the organelle inwards. First described for the intracellular movement of Listeria sp.
- RESORPTION LACUNA
-
The contained, low-pH subosteoclastic environment that is delimited by a dense circumferential ring of actin that forms a tight adhesive contact, or sealing zone. Lytic enzymes and H+ that promote bone erosion are secreted into this sealed environment.
- TPA
-
(12,13-tetradecanoyl phorbol acetate). Also known as phorbol myristoyl acetate, this is the most common phorbol ester. Phorbol esters are polycyclic esters that are isolated from croton oil. They are potent co-carcinogens or tumour promoters because they mimic diacylglycerol, and thereby irreversibly activate protein kinase C.
- GUANINE NUCLEOTIDE-EXCHANGE FACTOR
-
(GEF). A protein that facilitates the exchange of GDP (guanine diphosphate) for GTP (guanine triphosphate) in the nucleotide-binding pocket of a GTP-binding protein.
- PLECKSTRIN-HOMOLOGY (PH) DOMAIN
-
A sequence of 100 amino acids that is present in many signalling molecules and binds to lipid products of phosphatidyl-inositol 3-kinase. Pleckstrin is a protein of unknown function that was originally identified in platelets. It is a principal substrate of protein kinase C.
- GTPase-ACTIVATING PROTEINS
-
(GAPs). Proteins that inactivate small GTP-binding proteins, such as Ras-family members, by increasing their rate of GTP hydrolysis.
- MOTOGENS
-
Compounds that induce cell motility.
Rights and permissions
About this article
Cite this article
Buccione, R., Orth, J. & McNiven, M. Foot and mouth: podosomes, invadopodia and circular dorsal ruffles. Nat Rev Mol Cell Biol 5, 647–657 (2004). https://doi.org/10.1038/nrm1436
Issue Date:
DOI: https://doi.org/10.1038/nrm1436