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Polarization and Movement of Keratocytes: A Multiscale Modelling Approach

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Abstract

Eukariotic cell motility is a complex phenomenon, in which the cytoskeleton and its major constituent, actin, play an essential role. Actin forms polymers of long, stiff filaments that are cross-linked into an anisotropic network inside a thin sheet-like cellular protrusion, the lamellipod. At the leading edge of this structure, polymerization of actin filaments creates the force that pushes out the membrane and leads to translocation of a motile cell. Dynamics of the actin network account for changes in cell shape, crawling motion and turning of the cell in response to external cues. Regulating the dynamics of the cytoskeleton, and playing a central role in signal transduction in the cell, are Cdc42, Rac and Rho (GTPases of the rho family, collectively known as the small G-proteins) and the actin nucleating complex, Arp2/3.

In this paper, we use a multiscale modelling approach in a 2D model of a motile cell. We describe the mutual interactions of the small G-proteins, and their effects on capping and side-branching of actin filaments. We incorporate the pushing exerted by oriented actin filament ends on the cell edge, and a Rho-dependent contraction force. Combining these biochemical and mechanical aspects, we investigate the dynamics of a model epidermal fish keratocyte through in silico experiments. Our model gives insight into how, in response to some cue, a cell can polarize, form a leading edge, and move; concomitantly it explains how a keratocyte cell can maintain its shape and polarity, even after removal of the initial stimulus, and how it can change direction quickly in response to changes in its environment. We show that establishment of polarity stems from interactions of Cdc42, Rac and Rho, while maintenance and robustness of polarity is due to the rapid cytosolic diffusion of the inactive (GDI-bound) forms of the small G-proteins. Our model produces a cell shape that closely resembles the keratocytes and correct speeds for biologically reasonable parameter values. Movies of the simulations can be obtained from http://theory.bio.uu.nl/stan/keratocyte.

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References

  • Abercrombie, M., 1980. The Croonian Lecture, 1978: The crawling movement of metazoan cells. Proc. R. Soc. Lond. Ser. B 207, 129–147.

    Article  Google Scholar 

  • Abraham, V.C., Krishnamurthi, V., Taylor, D.L., Lanni, F., 1999. The actin-based nanomachine at the leading edge of migrating cells. Biophys. J. 77(3), 1721–1732.

    Google Scholar 

  • Allen, W.E., Zicha, D., Ridley, A.J., Jones, G.E., 1998. A role for Cdc42 in macrophage chemotaxis. J. Cell Biol. 141(5), 1147–1157.

    Google Scholar 

  • Amann, K.J., Pollard, T.D., 2001. Direct real-time observation of actin filament branching mediated by Arp2/3 complex using total internal reflection fluorescence microscopy. Proc. Natl. Acad. Sci. U.S.A. 98(26), 15009–15013.

    Google Scholar 

  • Asano, Y., Mizuno, T., Kon, T., Nagasaki, A., Sutoh, K., Uyeda, T.Q.P., 2004. Keratocyte-like locomotion in amiB-null Dictyostelium cells. Cell Motil. Cytoskeleton 59(1), 17–27.

    Google Scholar 

  • Baird, D., Feng, Q., Cerione, R.A., 2005. The Cool-2/α-Pix protein mediates a Cdc42-Rac signaling cascade. Curr. Biol. 15(1), 1–10.

    Google Scholar 

  • Benard, V., Bohl, B.P., Bokoch, G.M., 1999. Characterization of Rac and Cdc42 activation in chemoattractant-stimulated human neutrophils using a novel assay for active GTPases. J. Biol. Chem. 274(19), 13198–13204.

    Google Scholar 

  • Borghans, J.A.M., De Boer, R.J., Segel, L.A., 1996. Extending the quasi-steady state approximation by changing variables. Bull. Math. Biol. 58(1), 43–63.

    MATH  Google Scholar 

  • Bottino, D., Mogilner, A., Roberts, T., Stewart, M., Oster, G., 2002. How nematode sperm crawl. J. Cell Sci. 115(Pt 2), 367–384.

    Google Scholar 

  • Boukharov, A.A., Cohen, C.M., 1998. Guanine nucleotide-dependent translocation of RhoA from cytosol to high affinity membrane binding sites in human erythrocytes. Biochem. J. 330, 1391–1398.

    Google Scholar 

  • Burridge, K., Wennerberg, K., 2004. Rho and Rac take center stage. Cell 116(2), 167–179.

    Google Scholar 

  • Cameron, L.A., Svitkina, T.M., Vignjevic, D., Theriot, J.A., Borisy, G.G., 2001. Dendritic organization of actin comet tails. Curr. Biol. 11(2), 130–135.

    Google Scholar 

  • Carlsson, A.E., 2001. Growth of branched actin networks against obstacles. Biophys. J. 81(4), 1907–1923.

    MathSciNet  Google Scholar 

  • Carlsson, A.E., 2003. Growth velocities of branched actin networks. Biophys. J. 84(5), 2907–2918.

    Article  Google Scholar 

  • Caron, E., 2003. Rac signalling: A radical view. Nat. Cell Biol. 5(3), 185–187.

    Google Scholar 

  • Cramer, L.P., Mitchison, T.J., Theriot, J.A., 1994. Actin-dependent motile forces and cell motility. Curr. Opin. Cell Biol. 6(1), 82–86.

    Google Scholar 

  • Dawes, A.T., Edelstein-Keshet, L., 2006. Phosphoinositides and Rho proteins spatially regulate actin polymerization to initiate and maintain directed movement in a 1D model of a motile cell. submitted.

  • DiMilla, P.A., Barbee, K., Lauffenburger, D.A., 1991. Mathematical model for the effects of adhesion and mechanics on cell migration speed. Biophys. J. 60(1), 15–37.

    Google Scholar 

  • Ehrengruber, M.U., Deranleau, D.A., Coates, T.D., 1996. Shape oscillations of human neutrophil leukocytes: Characterization and relationship to cell motility. J. Exp. Biol. 199(Pt 4), 741–747.

    Google Scholar 

  • Etienne-Manneville, S., 2004. Cdc42–-the centre of polarity. J. Cell Sci. 117(Pt 8), 1291–1300.

    Google Scholar 

  • Falet, H., Hoffmeister, K.M., Neujahr, R., Italiano, J.E. Jr, Stossel, T.P., Southwick, F.S., Hartwig, J.H., 2002. Importance of free actin filament barbed ends for Arp2/3 complex function in platelets and fibroblasts. Proc. Natl. Acad. Sci. U.S.A. 99(26), 16782–16787.

    Google Scholar 

  • Fashena, S.J., Einarson, M.B., O'Neill, G.M., Patriotis, C., Golemis, E.A., 2002. Dissection of HEF1-dependent functions in motility and transcriptional regulation. J. Cell Sci. 115(Pt 1), 99–111.

    Google Scholar 

  • Firtel, R.A., Chung, C.Y., 2000. The molecular genetics of chemotaxis: Sensing and responding to chemoattractant gradients. BioEssays 22(7), 603–615.

    Google Scholar 

  • Fischer, R.S., Fritz-Six, K.L., Fowler, V.M., 2003. Pointed-end capping by tropomodulin3 negatively regulates endothelial cell motility. J. Cell Biol. 161(2), 371–380.

    Google Scholar 

  • Fleming, I.N., Elliott, C.M., Exton, J.H., 1996. Differential translocation of Rho family GTPases by lysophosphatidic acid, endothelin-1, and platelet-derived growth factor. J. Biol. Chem. 271(51), 33067–33073.

    Google Scholar 

  • Funamoto, S., Meili, R., Lee, S., Parry, L., Firtel, R.A., 2002. Spatial and temporal regulation of 3-phosphoinositides by PI 3-kinase and PTEN mediates chemotaxis. Cell 109(5), 611–623.

    Google Scholar 

  • Galbraith, C.G., Sheetz, M.P., 1999. Keratocytes pull with similar forces on their dorsal and ventral surfaces. J. Cell Biol. 147(6), 1313–1324.

    Google Scholar 

  • Gamba, A., De Candia, A., Di Talia, S., Coniglio, A., Bussolino, F., Serini, G., 2005. Diffusion-limited phase separation in eukaryotic chemotaxis. Proc. Natl. Acad. Sci. U.S.A. 102(47), 16927–16932.

    Google Scholar 

  • Gardner, T.S., Cantor, C.R., Collins, J.J., 2000. Construction of a genetic toggle switch in Escherichia. Coli. Nature 403(6767), 339–342.

    Google Scholar 

  • Giniger, E., 2002. How do Rho family GTPases direct axon growth and guidance? A proposal relating signaling pathways to growth cone mechanics. Differentiation 70(8), 385–396.

    Google Scholar 

  • Glazier, J.A., Graner, F., 1993. Simulation of the differential adhesion driven rearrangement of biological cells. Phys. Rev. E 47(3), 2128–2154.

    Google Scholar 

  • Goodwin, J.S., Drake, K.R., Remmert, C.L., Kenworthy, A.K., 2005. Ras diffusion is sensitive to plasma membrane viscosity. Biophys. J. 89(2), 1398–1410.

    Google Scholar 

  • Gracheva, M.E., Othmer, H.G., 2004. A continuum model of motility in ameboid cells. Bull. Math. Biol. 66(1), 167–193.

    MathSciNet  Google Scholar 

  • Graner, F., 1993. Can surface adhesion drive cell-rearrangement? Part I: Biological cell-sorting. J. Theor. Biol. 164, 455–476.

    Google Scholar 

  • Grimm, H.P., Verkhovsky, A.B., Mogilner, A., Meister, J.-J., 2003. Analysis of actin dynamics at the leading edge of crawling cells: Implications for the shape of keratocyte lamellipodia. Eur. Biophys. J. 32(6), 563–577.

    Google Scholar 

  • Hall, A., 1998. Rho GTPases and the actin cytoskeleton. Science 279(5350), 509–514.

    Google Scholar 

  • Haugh, J.M., Codazzi, F., Teruel, M., Meyer, T., 2000. Spatial sensing in fibroblasts mediated by 3' phosphoinositides. J. Cell Biol. 151(6), 1269–1280.

    Google Scholar 

  • Higgs, H.N., Pollard, T.D., 1999. Regulation of actin polymerization by Arp2/3 complex and WASp/Scar proteins. J. Biol. Chem. 274(46), 32531–32534.

    Google Scholar 

  • Higgs, H.N., Pollard, T.D., 2000. Activation by Cdc42 and PIP2 of Wiskott-Aldrich syndrome protein (WASp) stimulates actin nucleation by Arp2/3 complex. J. Cell Biol. 150(6), 1311–1320.

    Google Scholar 

  • Huang, M., Yang, C., Schafer, D.A., Cooper, J.A., Higgs, H.N., Zigmond, S.H., 1999. Cdc42-induced actin filaments are protected from capping protein. Curr. Biol. 9(17), 979–982.

    Google Scholar 

  • Jilkine, A., 2005. Modelling the interactions of small GTPases. Master's thesis, University of British Columbia, Canada.

    Google Scholar 

  • Jilkine, A., Marée, A.F.M., Edelstein-Keshet, L., 2006. Mathematical model for spatial segregation of the Rho-family GTPases based on inhibitory crosstalk. submitted.

  • Jim9nez, C., Portela, R.A., Mellado, M., Rodríguez-Frade, J.M., Collard, J., Serrano, A., Martínez-A, C., Avila, J., Carrera, A.C., 2000. Role of the PI3K regulatory subunit in the control of actin organization and cell migration. J. Cell Biol. 151(2), 249–262.

    Google Scholar 

  • Kaibuchi, K., Kuroda, S., Amano, M., 1999. Regulation of the cytoskeleton and cell adhesion by the Rho family GTPases in mammalian cells. Annu. Rev. Biochem. 68, 459–486.

    Google Scholar 

  • Kiosses, W.B., Daniels, R.H., Otey, C., Bokoch, G.M., Schwartz. M.A., 1999. A role for p21-activated kinase in endothelial cell migration. J. Cell Biol. 147(4), 831–844.

    Google Scholar 

  • Kole, T.P., Tseng, Y., Jiang, I., Katz, J.L., Wirtz, D., 2005. Intracellular mechanics of migrating fibroblasts. Mol. Biol. Cell 16(1), 328–338.

    Google Scholar 

  • Kraynov, V.S., Chamberlain, C., Bokoch, G.M., Schwartz, M.A., Slabaugh, S., Hahn, K.M., 2000. Localized Rac activation dynamics visualized in living cells. Science 290(5490), 333–337.

    Google Scholar 

  • Krewson, C.E., Chung, S.W., Dai, W.G., Saltzman, W.M., 1994. Cell-aggregation and neurite growth in gels of extracellular-matrix molecules. Biotechnol. Bioeng. 43(7), 555–562.

    Google Scholar 

  • Kurokawa, K., Itoh, R.E., Yoshizaki, H., Nakamura, Y.O.T., Matsuda, M., 2004. Coactivation of Rac1 and Cdc42 at lamellipodia and membrane ruffles induced by epidermal growth factor. Mol. Biol. Cell 15(3), 1003–1010.

    Google Scholar 

  • Landau, L.D., Lifshitz, E.M., 1976. Mechanics, Volume 1 of Course of Theoretical Physics, 3rd edition. Butterworth-Heinemann, Oxford.

    Google Scholar 

  • Lauffenburger, D.A., 1989. A simple model for the effects of receptor-mediated cell–substratum adhesion on cell migration. Chem. Eng. Sci. 44(9), 1903–1914.

    Google Scholar 

  • Laurent, V.M., Kasas, S., Yersin, A., Schäffer, T.E., Catsicas, S., Dietler, G., Verkhovsky, A.B., Meister, J.-J., 2005. Gradient of rigidity in the lamellipodia of migrating cells revealed by atomic force microscopy. Biophys. J. 89(1), 667–675.

    Google Scholar 

  • Lee, J., Jacobson, K., 1997. The composition and dynamics of cell–substratum adhesions in locomoting fish keratocytes. J. Cell Sci. 110, 2833–2844.

    Google Scholar 

  • Levchenko, A., Iglesias, P.A., 2002. Models of eukaryotic gradient sensing: Application to chemotaxis of amoebae and neutrophils. Biophys. J. 82(1 Pt 1), 50–63.

    Google Scholar 

  • Maly, I.V., Borisy, G.G., 2001. Self-organization of a propulsive actin network as an evolutionary process. Proc. Natl. Acad. Sci. U.S.A. 98(20), 11324–11329.

    Google Scholar 

  • Mar9e, A.F.M., Hogeweg, P., 2001. How amoeboids self-organize into a fruiting body: Multicellular coordination in Dictyostelium discoideum. Proc. Natl. Acad. Sci. U.S.A. 98(7), 3879–3883.

    Google Scholar 

  • Marion, J.B., Thornton, S.T., 1995. Classical Dynamics of Particles and Systems, chapter 7, 4th edition. Harcourt Brace, Fort Worth.

    Google Scholar 

  • Matozaki, T., Nakanishi, H., Takai, Y., 2000. Small G-protein networks: Their crosstalk and signal cascades. Cell. Signal. 12(8), 515–524.

    Google Scholar 

  • Meili, R., Firtel, R.A., 2003. Two poles and a compass. Cell 114(2), 153–156.

    Google Scholar 

  • Meinhardt, H., 2003. Complex pattern formation by a self-destabilization of established patterns: Chemotactic orientation and phyllotaxis as examples. C. R. Biol. 326(2), 223–237.

    Google Scholar 

  • Metropolis, N., Rosenbluth, A.E., Rosenbluth, M.N., Teller, A.H., Teller, E., 1953. Equation of state calculations by fast computing machines. J. Chem. Phys. 21, 1087–1092.

    Google Scholar 

  • Michaelson, D., Silletti, J., Murphy, G., D'Eustachio, P., Rush, M., Philips, M.R., 2001. Differential localization of Rho GTPases in live cells: Regulation by hypervariable regions and RhoGDI binding. J. Cell Biol. 152(1), 111–126.

    Google Scholar 

  • Mogilner, A., Edelstein-Keshet, L., 2002. Regulation of actin dynamics in rapidly moving cells: A quantitative analysis. Biophys. J. 83(3), 1237–1258.

    Google Scholar 

  • Mogilner, A., Oster, G., 1996a. Cell motility driven by actin polymerization. Biophys. J. 71(6), 3030–3045.

    Google Scholar 

  • Mogilner, A., Oster, G., 1996b. The physics of lamellipodial protrusion. Eur. Biophys. J. 25(1), 47–53.

    Google Scholar 

  • Mogilner, A., Oster, G., 2003. Force generation by actin polymerization II: The elastic ratchet and tethered filaments. Biophys. J. 84(3), 1591–1605.

    Google Scholar 

  • Mombach, J.C.M., Glazier, J.A., Raphael, R.C., Zajac, M., 1995. Quantitative comparison between differential adhesion models and cell sorting in the presence and absence of fluctuations. Phys. Rev. Lett. 75(11), 2244–2247.

    Google Scholar 

  • Mullins, R.D., Heuser, J.A., Pollard, T.D., 1998. The interaction of Arp2/3 complex with actin: Nucleation, high affinity pointed end capping, and formation of branching networks of filaments. Proc. Natl. Acad. Sci. U.S.A. 95(11), 6181–6186.

    Google Scholar 

  • Mullins, R.D., Stafford, W.F., Pollard, T.D., 1997. Structure, subunit topology, and actin-binding activity of the Arp2/3 complex from Acanthamoeba. J. Cell Biol. 136(2), 331–343.

    Google Scholar 

  • Nalbant, P., Hodgson, L., Kraynov, V., Toutchkine, A., Hahn, K.M., 2004. Activation of endogenous Cdc42 visualized in living cells. Science 305(5690), 1615–1619.

    Google Scholar 

  • Narang, A., 2006. Spontaneous polarization in eukaryotic gradient sensing: A mathematical model based on mutual inhibition of frontness and backness pathways. J. Theor. Biol., 240(4), 538–553.

    Google Scholar 

  • Neely, M.D., Nicholls, J.G., 1995. Electrical activity, growth cone motility and the cytoskeleton. J. Exp. Biol. 198(Pt 7), 1433–1446.

    Google Scholar 

  • Nishiura, Y., 1991. Singular limit approach to stability and bifurcation for bistable reaction diffusion-systems. Rocky Mt. J. Math. 21(2), 727–767.

    Article  MATH  MathSciNet  Google Scholar 

  • Nobes, C.D., Hall, A., 1995. Rho, Rac, and Cdc42 GTPases regulate the assembly of multimolecular focal complexes associated with actin stress fibers, lamellipodia, and filopodia. Cell 81(1), 53–62.

    Google Scholar 

  • Nobes, C.D., Hall, A., 1999. Rho GTPases control polarity, protrusion, and adhesion during cell movement. J. Cell Biol. 144(6), 1235–1244.

    Google Scholar 

  • Parent, C.A., Devreotes, P.N., 1999. A cell's sense of direction. Science 284(5415), 765–770.

    Google Scholar 

  • Pollard, T.D., Blanchoin, L., Mullins, R.D., 2000. Molecular mechanisms controlling actin filament dynamics in nonmuscle cells. Annu. Rev. Biophys. Biomol. Struct. 29, 545–576.

    Google Scholar 

  • Pollard, T.D., Borisy, G.G., 2003. Cellular motility driven by assembly and disassembly of actin filaments. Cell 112(4), 453–465.

    Google Scholar 

  • Postma, M., Bosgraaf, L., Loovers, H.M., Van Haastert, P.J.M., 2004. Chemotaxis: Signalling modules join hands at front and tail. EMBO Rep. 5(1), 35–40.

    Google Scholar 

  • Postma, M., Van Haastert, P.J.M., 2001. A diffusion-translocation model for gradient sensing by chemotactic cells. Biophys. J. 81(3), 1314–1323.

    Google Scholar 

  • Raftopoulou, M., Hall, A., 2004. Cell migration: Rho GTPases lead the way. Dev. Biol. 265(1), 23–32.

    Google Scholar 

  • Ream, R.A., Theriot, J.A., Somero, G.N., 2003. Influences of thermal acclimation and acute temperature change on the motility of epithelial wound-healing cells (keratocytes) of tropical, temperate and Antarctic fish. J. Exp. Biol. 206(Pt 24), 4539–4551.

    Google Scholar 

  • Redmond, T., Zigmond, S.H., 1993. Distribution of F-actin elongation sites in lysed polymorphonuclear leukocytes parallels the distribution of endogenous F-actin. Cell Motil. Cytoskeleton 26(1), 7–18.

    Google Scholar 

  • Ridley, A.J., 2001a. Rho family proteins: Coordinating cell responses. Trends Cell Biol. 11(12), 471–477.

    Google Scholar 

  • Ridley, A.J., 2001b. Rho GTPases and cell migration. J. Cell Sci. 114(Pt 15), 2713–2722.

    Google Scholar 

  • Ridley, A.J., Paterson, H.F., Johnston, C.L., Diekmann, D., Hall, A., 1992. The small GTP-binding protein Rac regulates growth factor-induced membrane ruffling. Cell 70(3), 401–410.

    Google Scholar 

  • Rubinstein, B., Jacobson, K., Mogilner, A., 2005. Multiscale two-dimensional modeling of a motile simple-shaped cell. SIAM Multiscale Model. Simul. 3(2), 413–439.

    MATH  MathSciNet  Google Scholar 

  • Sako, Y., Hibino, K., Miyauchi, T., Miyamoto, Y., Ueda, M., Yanagida, T., 2000. Single-molecule imaging of signaling molecules in living cells. Single Mol. 1(2), 159–163.

    Google Scholar 

  • Sakumura, Y., Tsukada, Y., Yamamoto, N., Ishii, S., 2005. A molecular model for axon guidance based on cross talk between rho GTPases. Biophys. J. 89(2), 812–822.

    Google Scholar 

  • Sander, E.E., Ten Klooster, J.-P., Van Delft, S., Van Der Kammen, R.A., Collard, J.G., 1999. Rac downregulates Rho activity: Reciprocal balance between both GTPases determines cellular morphology and migratory behavior. J. Cell Biol. 147(5), 1009–1022.

    Google Scholar 

  • Segel, L.A., 2001. Computing an organism. Proc. Natl. Acad. Sci. U.S.A. 98(7), 3639–3640.

    Google Scholar 

  • Steinmetz, M.O., Stoffler, D., Hoenger, A., Bremer, A., Aebi, U., 1997. Actin: From cell biology to atomic detail. J. Struct. Biol. 119(3), 295–320.

    Google Scholar 

  • Suetsugu, S., Miki, H., Takenawa, T., 2002. Spatial and temporal regulation of actin polymerization for cytoskeleton formation through Arp2/3 complex and WASP/WAVE proteins. Cell Motil. Cytoskeleton 51(3), 113–122.

    Google Scholar 

  • Svitkina, T.M., Borisy, G.G., 1999. Arp2/3 complex and actin depolymerizing factor/cofilin in dendritic organization and treadmilling of actin filament array in lamellipodia. J. Cell Biol. 145(5), 1009–1026.

    Google Scholar 

  • Svitkina, T.M., Verkhovsky, A.B., McQuade, K.M., Borisy, G.G., 1997. Analysis of the actin–myosin II system in fish epidermal keratocytes: Mechanism of cell body translocation. J. Cell Biol. 139(2), 397–415.

    Google Scholar 

  • Takai, Y., Sasaki, T., Matozaki, T., 2001. Small GTP-binding proteins. Physiol. Rev. 81(1), 153–208.

    Google Scholar 

  • Takubo, T., Tatsumi, N., 1997. Distribution of myosin and actin in moving human neutrophils detected by double-fluorescence staining. Anal. Quant. Cytol. Histol. 19(3), 233–238.

    Google Scholar 

  • Tsuji, T., Ishizaki, T., Okamoto, M., Higashida, C., Kimura, K., Furuyashiki, T., Arakawa, Y., Birge, R.B., Nakamoto, T., Hirai, H., Narumiya, S., 2002. ROCK and mDia1 antagonize in Rho-dependent Rac activation in Swiss 3T3 fibroblasts. J. Cell Biol. 157(5), 819–830.

    Google Scholar 

  • Vallotton, P., Gupton, S.L., Waterman-Storer, C.M., Danuser, G., 2004. Simultaneous mapping of filamentous actin flow and turnover in migrating cells by quantitative fluorescent speckle microscopy. Proc. Natl. Acad. Sci. U.S.A. 101(26), 9660–9665.

    Google Scholar 

  • Van Leeuwen, F.N., Kain, H.E.T., Van Der Kammen, R.A., Michiels, F., Kranenburg, O.W., Collard, J.G., 1997. The guanine nucleotide exchange factor Tiam1 affects neuronal morphology: Opposing roles for the small GTPases Rac and Rho. J. Cell Biol. 139(3), 797–807.

    Google Scholar 

  • Verkhovsky, A.B., Chaga, O.Y., Schaub, S., Svitkina, T.M., Meister, J.-J., Borisy, G.G., 2003. Orientational order of the lamellipodial actin network as demonstrated in living motile cells. Mol. Biol. Cell 14(11), 4667–4675.

    Google Scholar 

  • Verkhovsky, A.B., Svitkina, T.M., Borisy, G.G., 1999. Self-polarization and directional motility of cytoplasm. Curr. Biol. 9(1), 11–20.

    Google Scholar 

  • Wells, A., Gupta, K., Chang, P., Swindle, S., Glading, A., Shiraha, H., 1998. Epidermal growth factor receptor-mediated motility in fibroblasts. Microsc. Res. Tech. 43(5), 395–411.

    Google Scholar 

  • Wittmann, T., Waterman-Storer, C.M., 2001. Cell motility: Can Rho GTPases and microtubules point the way? J. Cell Sci. 114(Pt 21), 3795–3803.

    Google Scholar 

  • Xu, J., Wang, F., Van Keymeulen, A., Herzmark, P., Straight, A., Kelly, K., Takuwa, Y., Sugimoto, N., Mitchison, T., Bourne, H.R., 2003. Divergent signals and cytoskeletal assemblies regulate self-organizing polarity in neutrophils. Cell 114(2), 201–214.

    Google Scholar 

  • Zebda, N., Bernard, O., Bailly, M., Welti, S., Lawrence, D.S., Condeelis, J.S., 2000. Phosphorylation of ADF/cofilin abolishes EGF-induced actin nucleation at the leading edge and subsequent lamellipod extension. J. Cell Biol. 151(5), 1119–1128.

    Google Scholar 

  • Zhang, B., Zheng, Y., 1998. Regulation of RhoA GTP hydrolysis by the GTPase-activating proteins p190, p50RhoGAP, Bcr, and 3BP-1. Biochemistry 37(15), 5249–5257.

    Google Scholar 

  • Zondag, G.C.M., Evers, E.E., Ten Klooster, J.-P., Janssen, L., Van Der Kammen, R.A., Collard, J.G., 2000. Oncogenic Ras downregulates Rac activity, which leads to increased Rho activity and epithelial-mesenchymal transition. J. Cell Biol. 149(4), 775–782.

    Google Scholar 

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Marée, A.F.M., Jilkine, A., Dawes, A. et al. Polarization and Movement of Keratocytes: A Multiscale Modelling Approach. Bull. Math. Biol. 68, 1169–1211 (2006). https://doi.org/10.1007/s11538-006-9131-7

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