Advertisement
JBC

HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Originally published In Press as doi:10.1074/jbc.R700020200 on June 18, 2007

J. Biol. Chem., Vol. 282, Issue 32, 23005-23009, August 10, 2007
This Article
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
282/32/23005    most recent
R700020200v1
Right arrow Submit a Letter to Editor
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowRequest Permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Carlier, M.-F.
Right arrow Articles by Pantaloni, D.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Carlier, M.-F.
Right arrow Articles by Pantaloni, D.
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati  
What's this?

Minireview

Control of Actin Assembly Dynamics in Cell Motility*

Marie-France Carlier1 and Dominique Pantaloni

From the Cytoskeleton Dynamics and Motility Group, Laboratoire d'Enzymologie et Biochimie Structurale, CNRS, Gif-sur-Yvette 91198, France


   INTRODUCTION
TOP
 INTRODUCTION
Control of Filament Barbed...
 Control of the G-actin/F-actin...
 Insight into the Mechanism...
 Attachments between the Membrane...
 Concluding Remarks
 REFERENCES
 
Motile processes at the origin of cell migration, cell division, synaptic plasticity, and endocytosis, but also morphogenetic processes that define anterior-posterior and ventral-dorsal polarity of the embryo, or left-right asymmetry, are driven by spatially and temporally controlled assembly of actin filaments (1–4). Cell biological studies and reconstituted motility assays indicate that polarized filament barbed end growth, at specific sites on the membrane, generates the forces responsible for lamellipodia and filopodia extension, as well as tensile forces that strengthen focal adhesions. Fluorescence speckle microscopy of actin and regulatory proteins in motile cells show that morphologically and dynamically distinct networks of actin filaments initiated at the plasma membrane coexist in the cell and define cellular compartments (5, 6). How are these different turnover rates coordinated to achieve directional movement in response to extracellular cues? How can regulatory proteins recognize distinct actin networks? What are the relationships between the force produced by filament barbed end growth that deforms the membrane and the molecular mechanism of the protein machineries that link barbed ends to the membrane? New insights into these issues have emerged from recent cellular, physical, and biochemical approaches.


   Control of Filament Barbed End Growth
TOP
 INTRODUCTION
 Control of Filament Barbed...
Control of the G-actin/F-actin...
 Insight into the Mechanism...
 Attachments between the Membrane...
 Concluding Remarks
 REFERENCES
 
In living cells, actin filaments (F-actin) are assembled at a steady state and turn over via pointed end depolymerization balanced by barbed end polymerization, a process called treadmilling. The treadmilling of pure muscle actin is very slow (on the order of 0.1 subunit/s, meaning that a 3-µm-long filament is renewed in 2 h). Treadmilling is accelerated by 2 orders of magnitude in motile processes like lamellipodia or filopodia, due to the activity of ADF2/cofilins (7). In other structures like microvilli, treadmilling is slowed down by spatially regulated barbed end capping of, for example, actin bundles in the stereocilia of the inner ear (8). Treadmilling thus appears as a universal mechanism that drives actin dynamics in eukaryotes. The stationary concentration of polymerizable ATP-G-actin is determined by the overall flux of pointed end depolymerization and by the availability and reactivity of barbed ends. Both are finely regulated.

Polymerizable monomeric ATP-actin consists of free ATP-G-actin and complexes of ATP-G-actin with profilin or with functional homologs of profilin like WH2-domain proteins of the actobindin family (9–12). These proteins make a complex with G-actin that participates in barbed end assembly specifically. Profilin and its functional homologs thus play a crucial role in barbed end growth and motility. Most often, ATP-G-actin is in rapid equilibrium with these proteins (called collectively Wi), whereas filament assembly is an actual process. Each G-actin-Wi complex associates with free barbed ends with its own rate constant, k+iB, and displays its own intrinsic barbed end critical concentration, CCiB.

The steady-state concentrations of ATP-G-actin, [T]SS, and of the assembly-competent complexes, [TWi]SS, depend on the flux of pointed end depolymerization. Proteins of the ADF/cofilin family, acting in synergy with Aip1, enhance pointed end depolymerization in a signal-responsive fashion (13). By increasing the steady-state concentration of ATP-G-actin, they contribute to an increase in the rates of barbed end nucleation and growth. The specific localization of ADF in the lamellipodium has been explained recently by the fact that the ADF-activating Slingshot phosphatase (14, 15) becomes active by binding the filaments that are initiated upon lamellipodium formation (16).

The thermodynamic (CCiB) and kinetic (k+iB, k–iB) parameters are affected by proteins that associate with barbed ends and may block barbed end assembly and depolymerization (like capping proteins), slow down assembly and/or disassembly, or enhance barbed end growth like formins. Hence barbed ends are distributed in a variety of dynamically distinct classes. The values of [T]SS and [TWi]SS that are established at a given time in the cell depend on the number of filament pointed ends and on the number of barbed ends in each class (Fig. 1).

The kinetic parameters of capping protein interaction with barbed ends vary greatly from one protein to the other. Capping protein {alpha}beta dissociates so slowly from barbed ends that this process could be limiting in motility. The uncapping activity of CARMIL (17, 18) may therefore be important in the regulation of barbed end growth. The capping activity may also be integrated in a modular protein such as Eps8, which spatially and temporally restricts its function in response to local signals (19). Finally, a protein known to sequester ADP-actin, twinfilin, has also been identified as a capping protein. One of the consequences of the combined activities of twinfilin is revealed in an integrated motility assay in which formin and twinfilin operate simultaneously. The sequestration of ADP-actin has a buffering effect on the level of barbed end capping by twinfilin. In turn this buffering effect maintains a low activity of formin (20). These results should foster experiments aimed at testing the potential genetic interaction between twinfilin and formin. Conversely, the discovery of genetic interactions between two actin regulatory proteins should foster the design of reconstituted assays combining both proteins and leading toward the discovery of promising new properties.

Most capping proteins are soluble; however, proteins that nucleate barbed ends or that regulate barbed end growth rate often operate at the plasma membrane in a signal-responsive fashion. The best example is provided by formins. The autoinhibited fold of formins is relieved in two consecutive steps by the binding of RhoGTPase (21), thus targeting activated formin at the membrane. The function of formins in actin filament dynamics is tightly regulated by profilin, a cofactor that is required for the activity of formins in vivo. In the absence of profilin, formins nucleate filaments and cap barbed ends more or less tightly. Cdc12 is a strong capper (22), whereas mDia1 and Bni1 are "leaky" cappers (23). Formins use the property of profilin to couple ATP hydrolysis to filament assembly in order to catalyze rapid, processive, barbed end assembly, thus enhancing the rate constant for barbed end growth by 1 order of magnitude (28). Thus, rapid formin-based motile processes may occur concomitantly with other slower actin-based motile processes mediated by free barbed end growth, at a given steady-state concentration of ATP-G-actin. As a result, agents that lower the steady-state concentration of G-actin by stabilizing filaments (e.g. tropomyosin) are expected to further depress the formation of the branched filament array while still allowing formin-based motile processes.


Figure 1
View larger version (37K):
[in this window]
[in a new window]

  		FIGURE 1.
Coordinated treadmilling of distinct arrays of actin filaments in cell motility. This scheme emphasizes that an overall steady state of actin assembly allows different populations of filaments to coexist with distinct dynamics and barbed end growth rates. All filaments depolymerize from their pointed ends. ADF/cofilin binding to a fraction of actin filaments enhances pointed end depolymerization and feeds a pool of ADF-ADP-G-actin that feeds the pool of ATP-G-actin. ATP-G-actin is in rapid equilibrium with thymosin beta4 and with profilin (the "profilin-actin" pool actually encompasses the pool of all complexes of actin with proteins that are functional homologs of profilin). Barbed end growth is fed by ATP-G-actin and profilin-actin in various arrays: branched filaments initiated by immobilized N-WASP-Arp2/3 and nonbranched filaments processively assembled by formins. Note that a gradient of ADP-Pi-F-actin (red) to ADP-F-actin (blue) exists on filaments that assemble from G-actin and profilin-actin, whereas ATP hydrolysis is coupled to formin-catalyzed processive assembly of filaments from profilin-actin. Transient (N-WASP-Arp2/3-mediated) or permanent (formin-mediated) attachments of barbed ends occur at the membrane during barbed end growth. The rate of barbed end growth is controlled by proteins (weak or strong cappers, formin, etc.) bound to the barbed end in rapid equilibrium.

 
In conclusion, what we know from the biochemistry of actin and its regulators lets us anticipate that the assembly dynamics at individual barbed ends can vary to large extents in different regions of the cell. A more complex situation may occur if the diffusion of ATP-G-actin is low enough for significant gradients of G-actin to build up in regions of the cytoplasm.


   Control of the G-actin/F-actin Ratio: Sequestering Proteins
TOP
 INTRODUCTION
 Control of Filament Barbed...
 Control of the G-actin/F-actin...
Insight into the Mechanism...
 Attachments between the Membrane...
 Concluding Remarks
 REFERENCES
 
In addition to polymerizable G-actin, cells contain a pool of nonpolymerizable G-actin, which consists of ATP-G-actin (T) in complex with sequestering proteins (S) such as beta-thymosins (24). beta-Thymosin-actin complexes (TS) do not participate in filament assembly at either end and are in rapid equilibrium with free ATP-G-actin. Hence the amount of sequestered actin at steady state is determined at any time by the concentration of free ATP-G-actin, [T]SS,

Formula 1(Eq. 1)
where [S0] is the total concentration of sequestering agent, and KS ist he equilibrium dissociation constant for the TS complex. KS is higher than [T]SS, hence according to Equation 1, changes in [T]SS generate large changes in the pool of sequestered actin, reflected by changes in the amount of F-actin. G-actin sequesterers do not affect the velocity of motile processes, because the TS complex does not feed barbed end growth. However, they do affect the force produced, because they determine the amount of F-actin that builds up when the creation of new filaments in response to signals causes the relaxation of the steady state of actin assembly to a lower value of [T]SS. Note that this relaxation process takes place without any massive production of free ATP-G-actin. Measuring the concentrations of polymerizable and nonpolymerizable G-actin in vivo upon stimulus-induced changes in the motile state of the cell is a challenging task that will require refined imaging procedures that have not been developed yet.


   Insight into the Mechanism of Actin-based Motility from Reconstitution Assays
TOP
 INTRODUCTION
 Control of Filament Barbed...
 Control of the G-actin/F-actin...
 Insight into the Mechanism...
Attachments between the Membrane...
 Concluding Remarks
 REFERENCES
 
Forces produced by the growth of actin filaments against a membrane in response to signaling (25) generate lamellipodial and filopodial protrusions, internalization of endocytic vesicles, or propulsion of endosomes. Actin polymerization against the surface of intracellular pathogens Listeria and Shigella causes their propulsion, which makes these bacteria the first natural functionalized particles mimicking the leading edge of migrating cells. The reconstitution of actin-based propulsion of a particle functionalized with N-WASP (26, 27) or formin (28) in a solution of F-actin maintained at steady state with ATP as an energy source validated the principle of treadmilling as the fuel of movement in cells and delineated the minimum number of required proteins (ADF and profilin for formin and additionally Arp2/3 and capping proteins for N-WASP). The same proteins were found essential for lamellipodium extension in vivo (29). Reconstituted motility assays also enabled controlled measurements of the force produced by actin polymerization (30). WASP family proteins use Arp2/3 complex to branch filaments at the leading edge, whereas formins may contribute to lamellipodium or filopodium or nerve growth cone extension or even supplement the absence of Arp2/3 (31, 32).

How does a lamellipodium start extending? Arp2/3 generates new filaments only by branching. When an N-WASP-coated bead or vesicle is placed in a reconstituted motility solution of barbed end-capped filaments, Arp2/3, ADF, and profilin, the filaments are never seen to adsorb onto N-WASP-Arp2/3 bound to the surface. The unpolarized actin meshwork that forms at the bead surface actually starts from G-actin. The treadmilling model accounts for this fact as follows. The motility medium maintains a steady-state concentration of ATP-G-actin well above the critical concentration of barbed ends, favoring nucleation. Nuclei that have free barbed ends either abort by binding a barbed end capper or branch at the bead surface upon transient interaction with the N-WASP-actin-Arp2/3 complex. Branching thus transiently protects from barbed end capping. It is likely that the same mechanism accounts for the initiation of the branched lamellipodial array. Similarly, formins use the dimer pre-nuclei present at steady state to initiate processive barbed end growth of new filaments at the leading edge. This process is more likely than the capture of barbed ends of existing filaments, which cannot diffuse rapidly in this confined cellular environment.

How is actin assembly coordinated in the dendritic array and formin-induced bundles? How are the two arrays recognized by their specific regulators or bundling proteins? Reconstituted motility assays show that optimized actin-based movement is not obtained with the exact same medium composition for the WASP-Arp2/3 and formin systems. Propulsion of a WASP-functionalized particle by formation of a branched filament array relies on the balance between the sustained generation of new filaments at the particle surface by WASP-Arp2/3-induced filament branching and the disappearance of growing filaments by barbed end capping. This balance maintains a stationary number of growing filaments. The branched filament array thus contains an equal number of incorporated molecules of Arp2/3 and capping protein. Increasing the concentration of capping protein in the medium leads to an increase in the branching density of the meshwork (27).

In contrast, capping proteins, which compete with formin for barbed end binding, are negative regulators of the propulsion of formin-coated beads (28). In conclusion, in vitro capping proteins favor the formation of a highly densely branched array but inhibit formin-based processes. Remarkably, the same phenotype is observed in vivo (33): depletion of capping protein abolishes lamellipodia and favors formin-induced filopodia (34). In conclusion, the same physical-chemical principles govern the dynamics of individual machineries and organize the cross-talk between them.

The fact that two populations of filaments with different dynamics may be regulated by different proteins is amazing. The possibility cannot be discarded that the machineries that control barbed end growth also control the structure of the filament over some distance (35, 36). The actin filament has a versatile structure, and subtle structural changes induced by barbed end-binding regulators may favor the binding of, for example, distinctive bundling proteins, thus further differentiating the function of actin arrays. This might explain why bundling proteins like fascin (37) or espin (38) are found associated with bundles of filaments initiated by different machineries.


   Attachments between the Membrane and Actin Filaments during Protrusion: From Molecular Processes to Macroscopic Behavior
TOP
 INTRODUCTION
 Control of Filament Barbed...
 Control of the G-actin/F-actin...
 Insight into the Mechanism...
 Attachments between the Membrane...
Concluding Remarks
 REFERENCES
 
The directionality of cell protrusions is determined and maintained by dynamic links between the membrane and the actin filaments. Different mechanisms were proposed to link the membrane to growing filaments. The force-velocity relationships predicted by the models derived from these different mechanisms are different. Protrusive force produced by the growth of a branched filament array has been most extensively studied. Activated Arp2/3 complex is proposed to associate with the sides of actin filaments in the lamellipodium to initiate lateral branches. Insertional polymerization would occur in the small interval made available by the fluctuations of the membrane between the barbed ends and the lipid bilayer, and filaments would never attach to the membrane (39). This model is unable to reasonably account for directional protrusion. The perpetuation of the polarized dendritic pattern during sustained lamellipodium extension requires some kind of cyclic connection (either transient or permanent) between the membrane and the filaments as they grow (40). Biomimetic assays of propulsion of N-WASP-functionalized microspheres or vesicles have demonstrated that the actin tail is attached to the particle surface (30, 41, 42), suggesting that similar bonds exist between the filaments and the membrane during protrusion. Lateral mobility of lipids appears strongly hampered at the leading edge by association of filament barbed ends with membrane components (43). What kind of link then could generate filament attachment, yet allow barbed end growth? Are the attachments permanent during filament growth or transient? Are the attachments linked to the filament branching activity of N-WASP, or are they independent of branching? These issues, which are central to physical models of protrusion, are no doubt to be solved only by a thorough analysis of the biochemical steps in the reactions of filament branching and elongation by using solution polymerization kinetics, structural analysis of the complexes involved, and microscopy assays of individual filaments initiated at a surface. Progress is still anticipated from all methods.

Polymerization assays in bulk solution so far have provided conflicting results regarding the molecular mechanism of filament branching. Some data have favored side branching of filaments by Arp2/3 complex "activated" by N-WASP (44). Other data show that branching occurs at and requires free barbed ends (45–47). In the branching-activated Arp2/3 complex, the WH2 domain of N-WASP binds one molecule of G-actin, and the CA domain binds one molecule of Arp2/3. The WH2-actin subcomplex, like profilin-actin, can associate productively with barbed ends (48). Therefore N-WASP is an immobilized enzyme, either at the membrane or at the surface of Shigella or of beads. Arp2/3 complex, G-actin, and the filament are its substrates (49). It has been proposed that N-WASP-actin-Arp2/3 complex associates with a filament via productive association of WH2-actin to the barbed end with CA-Arp2/3 initiating a lateral branch. The rate of detachment of the branch junction from N-WASP plays a determining role in propulsion. In motility assays, a pulse of fluorescent Arp2/3 led to initial labeling of N-WASP at the bead surface followed by diffusional penetration of fluorescent Arp2/3 from the bead surface into the actin tail at a rate identical to filament growth (27). A model of "tethered ratchet" for actin-based motility was derived in which filaments are transiently attached to the bead surface (50, 51). Recent data show that the complex of the isolated WH2 domain with ATP-G-actin binds barbed ends and mediates the attachment of filaments at the bead-tail interface (52). The attachments appear dynamic when N-WASP, containing both WH2 and CA moieties, is able to branch filaments, whereas they remain quasi-permanent when only the WH2-actin moiety associates with barbed ends. It is possible that ATP hydrolysis causes dissociation of WH2 from the barbed end (53). The Arp2/3 complex may also play a role in the transient attachment. In support of this view, the segregation of N-WASP at the rear of propelling giant liposomes appears to depend on Arp2/3 complex.3

Structural organization of the subunits of Arp2/3 complex at the branch junction is expected to provide mechanistic insight into the branching process. Conflicting orientations of the complex axis have been proposed (54–56), and no information exists on the position of the WH2-bound actin incorporated in the branch. Biases may occur when computing differences in projection maps of branched filaments containing Arp2/3 associated or not with tags. In summary, the complete kinetic analysis of the elementary reactions involved in filament branching and the characterization of transient complexes in the cycle of filament attachment-branching are important future trends of research.

Formins do maintain a permanent attachment to the filament barbed ends during processive growth and truly behave as end-tracking stepping motors (57). The molecular mechanism of the processivity of formins and the role of ATP hydrolysis associated with profilin-actin processive assembly are not fully understood. Noninvasive methods have not always been used to show evidence for processivity, and forces that maintain growing filament ends in the vicinity of the immobilized formin may bias the conclusions. Some data indicate that filaments can be assembled processively from ADP-actin as well as from ATP-actin and that profilin is not required (58–60). Other data (28) indicate that formin uses a major property of profilin, which is to couple ATP hydrolysis to filament growth. The crystal structure of the formin-actin complex (61) shows that formin caps barbed ends and a structural change implying the weakening of a formin-actin contact is required to allow processive assembly. Recent data support the structural model. As long as ATP is not hydrolyzed following association of profilinactin to barbed ends, formin-bound profilin actually caps barbed ends (62). If ATP hydrolysis is involved in the processivity of formin, the forces developed by processive filament assembly may be much greater than the force of the order of a piconewton, which is produced by a freely fluctuating filament end (63). This measurement has not been performed yet. Biochemical and structural analysis of the transient complexes that are formed at the formin-bound barbed end is needed to understand how molecular reactions control macroscopic behavior.

Thus far formins and WASP/WAVE-Arp2/3 are the only known machineries that control barbed end nucleation and growth in motile processes. Other actin-binding proteins involved in morphogenetic or developmental processes are emerging. The WH2 domain protein Spire/Eg6 (64–66) plays a role in the definition of the anterior-posterior and dorso-ventral axes in early embryogenesis. Spire nucleates actin filaments in vitro (65). The phenotypes of mutants of Spire and of the formin Cappuccino are similar and are mimicked by profilin depletion, suggesting that some functional interplay links these three proteins to optimize barbed end growth in processes directing oocyte polarity.


   Concluding Remarks
TOP
 INTRODUCTION
 Control of Filament Barbed...
 Control of the G-actin/F-actin...
 Insight into the Mechanism...
 Attachments between the Membrane...
 Concluding Remarks
REFERENCES
 
Self-assembly of actin filaments is at the heart of morphogenesis and movement in eukaryotic cells. The in vivo analysis of the dynamics of distinct actin arrays, the discovery of protein machineries that couple actin filaments to membrane dynamics and signaling, the development of reconstituted motility assays, and the use of nanophysics methods to measure forces developed by actin have largely contributed to the expansion of the actin field to boundary disciplines. It may not be a dream to imagine that, using reconstituted systems of increasing complexity, the coordinated motility of an artificial cell will eventually be mimicked. The intrinsic properties of actin itself and their potential use by regulators are constantly being unveiled in the light of cellular phenomena. However, in many instances the analysis of molecular events using classical biochemical and structural approaches remains the limiting factor in future progress.


   FOOTNOTES
 
* This minireview will be reprinted in the 2007 Minireview Compendium, which will be available in January, 2008. This work was supported by HFSPO Grant RGP00722003-C, the ANR (Physique et Chimie du Vivant), the Ligue Nationale contre le Cancer (équipe labellisée), and the European STREP (BIOMICS). Back

1 To whom correspondence should be addressed. E-mail: carlier{at}lebs.cnrs-gif.fr.

2 The abbreviations used are: ADF, actin-depolymerizing factor; N-WASP, neural Wiscott-Aldrich syndrome protein. Back

3 V. Delatour, G. Romet-Lemonne, D. Didry, D. Pantaloni, E. Helfer, and M.-F. Carlier, submitted. Back



   REFERENCES
TOP
 INTRODUCTION
 Control of Filament Barbed...
 Control of the G-actin/F-actin...
 Insight into the Mechanism...
 Attachments between the Membrane...
 Concluding Remarks
 REFERENCES
 

  1. Pollard, T. D., and Borisy, G. G. (2003) Cell 112, 453–465[CrossRef][Medline] [Order article via Infotrieve]
  2. Rafelski, S. M., and Theriot, J. A. (2004) Annu. Rev. Biochem. 73, 209–239[CrossRef][Medline] [Order article via Infotrieve]
  3. Dormann, D., and Weijer, C. J. (2006) Curr. Opin. Genet. Dev. 16, 367–373[CrossRef][Medline] [Order article via Infotrieve]
  4. Kaksonen, M., Toret, C. P., and Drubin, D. G. (2006) Nat. Rev. Mol. Cell. Biol. 7, 404–414[CrossRef][Medline] [Order article via Infotrieve]
  5. Ponti, A., Machacek, M., Gupton, S. L., Waterman-Storer, C. M., and Danuser, G. (2004) Science 305, 1782–1786[Abstract/Free Full Text]
  6. Iwasa, J. H., and Mullins, R. D. (2007) Curr. Biol. 17, 395–406[CrossRef][Medline] [Order article via Infotrieve]
  7. Carlier, M. F., Ressad, F., and Pantaloni, D. (1999) J. Biol. Chem. 274, 33827–33830[Free Full Text]
  8. Lin, H. W., Schneider, M. E., and Kachar, B. (2005) Curr. Opin. Cell Biol. 17, 55–61[CrossRef][Medline] [Order article via Infotrieve]
  9. Paunola, E., Mattila, P. K., and Lappalainen, P. (2002) FEBS Lett. 513, 92–97[CrossRef][Medline] [Order article via Infotrieve]
  10. Boquet, I., Boujemaa, R., Carlier, M. F., and Preat, T. (2000) Cell 102, 797–808[CrossRef][Medline] [Order article via Infotrieve]
  11. Hertzog, M., Yarmola, E. G., Didry, D., Bubb, M. R., and Carlier, M. F. (2002) J. Biol. Chem. 277, 14786–14792[Abstract/Free Full Text]
  12. Hertzog, M., van Heijenoort, C., Didry, D., Gaudier, M., Coutant, J., Gigant, B., Didelot, G., Preat, T., Knossow, M., Guittet, E., and Carlier, M. F. (2004) Cell 117, 611–623[CrossRef][Medline] [Order article via Infotrieve]
  13. Ono, S., Mohri, K., and Ono, K. (2004) J. Biol. Chem. 279, 14207–14212[Abstract/Free Full Text]
  14. Niwa, R., Nagata-Ohashi, K., Takeichi, M., Mizuno, K., and Uemura, T. (2002) Cell 108, 233–246[CrossRef][Medline] [Order article via Infotrieve]
  15. Sarmiere, P. D., and Bamburg, J. R. (2004) J. Neurobiol. 58, 103–117[CrossRef][Medline] [Order article via Infotrieve]
  16. Nagata-Ohashi, K., Ohta, Y., Goto, K., Chiba, S., Mori, R., Nishita, M., Ohashi, K., Kousaka, K., Iwamatsu, A., Niwa, R., Uemura, T., and Mizuno, K. (2004) J. Cell Biol. 165, 465–471[Abstract/Free Full Text]
  17. Yang, C., Pring, M., Wear, M. A., Huang, M., Cooper, J. A., Svitkina, T. M., and Zigmond, S. H. (2005) Cell 119, 209–221[CrossRef]
  18. Uruno, T., Remmert, K., and Hammer, J. A., III (2006) J. Biol. Chem. 281, 10635–10650[Abstract/Free Full Text]
  19. Disanza, A., Carlier, M. F., Stradal, T. E., Didry, D., Frittoli, E., Confalonieri, S., Croce, A., Wehland, J., Di Fiore, P. P., and Scita, G. (2004) Nat. Cell Biol. 6, 1180–1188[CrossRef][Medline] [Order article via Infotrieve]
  20. Helfer, E., Nevalainen, E. M., Naumanen, P., Romero, S., Didry, D., Pantaloni, D., Lappalainen, P., and Carlier, M. F. (2006) EMBO J. 25, 1184–1195[CrossRef][Medline] [Order article via Infotrieve]
  21. Rose, R., Weyand, M., Lammers, M., Ishizaki, T., Ahmadian, M. R., and Wittinghofer, A. (2005) Nature 435, 513–518[CrossRef][Medline] [Order article via Infotrieve]
  22. Kovar, D. R., Kuhn, J. R., Tichy, A. L., and Pollard, T. D. (2003) J. Cell Biol. 161, 875–887[Abstract/Free Full Text]
  23. Li, F., and Higgs, H. N. (2003) Curr. Biol. 13, 1335–1340[CrossRef][Medline] [Order article via Infotrieve]
  24. Safer, D., and Nachmias, V. T. (1994) BioEssays 16, 473–479[CrossRef][Medline] [Order article via Infotrieve]
  25. Ridley, A. J. (2006) Trends Cell Biol. 16, 522–529[CrossRef][Medline] [Order article via Infotrieve]
  26. Loisel, T. P, Boujemaa, R., Pantaloni, D., and Carlier, M. F. (1999) Nature 401, 613–616[CrossRef][Medline] [Order article via Infotrieve]
  27. Wiesner, S., Helfer, E., Didry, D., Ducouret, G., Lafuma, F., Carlier, M. F., and Pantaloni, D. (2003) J. Cell Biol. 160, 387–398[Abstract/Free Full Text]
  28. Romero, S., Le Clainche, C., Didry, D., Egile, C., Pantaloni, D., and Carlier, M. F. (2004) Cell 119, 419–429[CrossRef][Medline] [Order article via Infotrieve]
  29. Rogers, S. L, Wiedemann, U., Stuurman, N., and Vale, R. D. (2003) J. Cell Biol. 162, 1079–1088[Abstract/Free Full Text]
  30. Marcy, Y., Prost, J., Carlier, M. F., and Sykes, C. (2004) Proc. Natl. Acad. Sci. U. S. A. 101, 5992–5997[Abstract/Free Full Text]
  31. Gupton, S. L., Anderson, K. L., Kole, T. P., Fischer, R. S., Ponti, A., Hitchcock-DeGregori, S. E., Danuser, G., Fowler, V. M., Wirtz, D., Hanein, D., and Waterman-Storer, C. M. (2005) J. Cell Biol. 168, 619–631[Abstract/Free Full Text]
  32. Nardo, A., Cicchetti, G., Falet, H., Hartwig, J. H., Stossel, T. P., and Kwiatkowski, D. J. (2005) Proc. Natl. Acad. Sci. U. S. A. 102, 16263–16268[Abstract/Free Full Text]
  33. Mejillano, M. R., Kojima, S., Applewhite, D. A., Gertler, F. B., Svitkina, T. M., and Borisy, G. G. (2004) Cell 118, 363–373[CrossRef][Medline] [Order article via Infotrieve]
  34. Shirenbeck, A., Bretschneider, T., Arasada, R., Schleicher, M., and Faix, J. (2005) Nat. Cell Biol. 7, 619–625[CrossRef][Medline] [Order article via Infotrieve]
  35. Orlova, A., Prochniewicz, E., and Egelman, E. H. (1995) J. Mol. Biol. 245, 598–607[CrossRef][Medline] [Order article via Infotrieve]
  36. Papp, G., Bugyi, B., Ujfalusi, Z., Barko, S., Hild, G., Somogyi, B., and Nyitrai, M. (2006) Biophys. J. 91, 2564–2572[CrossRef][Medline] [Order article via Infotrieve]
  37. Vignjevic, D., Kojima, S., Aratyn, Y., Danciu, O., Svitkina, T., and Borisy, G. G. (2006) J. Cell Biol. 174, 863–875[Abstract/Free Full Text]
  38. Sekerkova, G., Zheng, L., Loomis, P. A., Mugnaini, E., and Bartles, J. R. (2006) Cell. Mol. Life Sci. 63, 2329–2341[CrossRef][Medline] [Order article via Infotrieve]
  39. Pollard, T. D. (2007) Annu. Rev. Biophys. Biomol. Struct. 36, 461–477
  40. Takenawa, T., and Suetsugu, S. (2007) Nat. Rev. Mol. Cell. Biol. 8, 37–48[CrossRef][Medline] [Order article via Infotrieve]
  41. Gerbal, F., Laurent, V., Ott, A., Carlier, M. F., Chaikin, P., and Prost, J. (2000) Eur. Biophys. J. 29, 134–140[CrossRef][Medline] [Order article via Infotrieve]
  42. Trichet, L., Campas, O., Sykes, C., and Plastino, J. (2007) Biophys. J. 92, 1081–1089[CrossRef][Medline] [Order article via Infotrieve]
  43. Weisswange, I., Bretschneider, T., and Anderson, K. I. (2005) J. Cell Sci. 118, 4375–4380[Abstract/Free Full Text]
  44. Amann, K. J., and Pollard, T. D. (2001) Nat. Cell Biol. 3, 306–310[CrossRef][Medline] [Order article via Infotrieve]
  45. Pantaloni, D., Boujemaa, R., Didry, D., Gounon, P., and Carlier, M. F. (2000) Nat. Cell Biol. 2, 385–391[CrossRef][Medline] [Order article via Infotrieve]
  46. Boujemaa-Paterski, R., Gouin, E., Hansen, G., Samarin, S., Le Clainche, C., Didry, D., Dehoux, P., Cossart, P., Kocks, C., Carlier, M. F., and Pantaloni, D. (2001) Biochemistry 40, 11390–11404[CrossRef][Medline] [Order article via Infotrieve]
  47. Falet, H., Hoffmeister, K. M., Neujahr, R., Italiano, J. E., Jr., Stossel, T. P., Southwick, F. S., and Hartwig, J. H. (2002) Proc. Natl. Acad. Sci. U. S. A. 99, 16782–16787[Abstract/Free Full Text]
  48. Egile, C., Loisel, T. P., Laurent, V., Li, R., Pantaloni, D., Sansonetti, P. J., and Carlier, M. F. (1999) J. Cell Biol. 146, 1319–1332[Abstract/Free Full Text]
  49. Pantaloni, D., Le Clainche, C., and Carlier, M. F. (2001) Science 292, 1502–1506[Abstract/Free Full Text]
  50. Mogilner, A., and Oster, G. (2003) Biophys. J. 84, 1591–1605[Medline] [Order article via Infotrieve]
  51. Mogilner, A. (2006) Curr. Opin. Cell Biol. 18, 32–39[CrossRef][Medline] [Order article via Infotrieve]
  52. Co, C., Wong, D. T., Gierke, S., Chang, V., and Taunton, J. (2007) Cell 128, 901–913[CrossRef][Medline] [Order article via Infotrieve]
  53. Le Clainche, C., Pantaloni, D., and Carlier, M. F. (2003) Proc. Natl. Acad. Sci. U. S. A. 100, 6337–6342[Abstract/Free Full Text]
  54. Beltzner, C. C., and Pollard, T. D. (2004) J. Mol. Biol. 336, 551–565[CrossRef][Medline] [Order article via Infotrieve]
  55. Aguda, A. H., Burtnick, L. D., and Robinson, R. C. (2005) EMBO Rep. 6, 220–226[CrossRef][Medline] [Order article via Infotrieve]
  56. Egile, C., Rouiller, I., Xu, X. P., Volkmann, N., Li, R., and Hanein, D. (2005) PLoS Biol. 3, 30383
  57. Dickinson, R. B., Caro, L., and Purich, D. L. (2004) Biophys. J. 87, 2838–2854[CrossRef][Medline] [Order article via Infotrieve]
  58. Kovar, D. R., and Pollard, T. D. (2004) Proc. Natl. Acad. Sci. U. S. A. 101, 14725–14730[Abstract/Free Full Text]
  59. Kovar, D. R., Harris, E. S., Mahaffy, R., Higgs, H. N., and Pollard, T. D. (2006) Cell 124, 423–435[CrossRef][Medline] [Order article via Infotrieve]
  60. Vavylonis, D., Kovar, D. R., O'Shaughnessy, B., and Pollard, T. D. (2006) Mol. Cell 21, 455–466[CrossRef][Medline] [Order article via Infotrieve]
  61. Otomo, T., Tomchick, D. R., Otomo, C., Panchal, S. C., Machius, M., and Rosen, M. K. (2005) Nature 433, 488–494[CrossRef][Medline] [Order article via Infotrieve]
  62. Romero, S., Didry, D., Larquet, E., Boisset, N., Pantaloni, D., and Carlier, M. F. (2007) J. Biol. Chem. 282, 8435–8445[Abstract/Free Full Text]
  63. Footer, M. J., Kerssemakers, J. W., Theriot, J. A., and Dogterom, M. (2007) Proc. Natl. Acad. Sci. U. S. A. 104, 2181–2186[Abstract/Free Full Text]
  64. Wellington, A., Emmons, S., James, B., Calley, J., Grover, M., Tolias, P., and Manseau, L. (1999) Development (Camb.) 126, 5267–5274[Abstract]
  65. Quinlan, M. E., Heuser, J. E., Kerkhoff, E., and Mullins, R. D. (2005) Nature 433, 382–388[CrossRef][Medline] [Order article via Infotrieve]
  66. Le Goff, C., Laurent, V., Le Bon, K., Tanguy, G., Couturier, A., Le Goff, X., and Le Guellec, R. (2006) Biol. Cell 98, 697–708[CrossRef][Medline] [Order article via Infotrieve]

Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati    What's this?


This article has been cited by other articles:


Home page
 JCBHome page
P. Hotulainen, O. Llano, S. Smirnov, K. Tanhuanpaa, J. Faix, C. Rivera, and P. Lappalainen
Defining mechanisms of actin polymerization and depolymerization during dendritic spine morphogenesis
J. Cell Biol., April 20, 2009; 185(2): 323 - 339.
[Abstract] [Full Text] [PDF]

Home page
 J. Biol. Chem.Home page
R. Zhao, L. Du, Y. Huang, Y. Wu, and S. J. Gunst
Actin Depolymerization Factor/Cofilin Activation Regulates Actin Polymerization and Tension Development in Canine Tracheal Smooth Muscle
J. Biol. Chem., December 26, 2008; 283(52): 36522 - 36531.
[Abstract] [Full Text] [PDF]

Home page
 J. Biol. Chem.Home page
E. Stokasimov, M. McKane, and P. A. Rubenstein
Role of Intermonomer Ionic Bridges in the Stabilization of the Actin Filament
J. Biol. Chem., December 12, 2008; 283(50): 34844 - 34854.
[Abstract] [Full Text] [PDF]

Home page
 Mol. Biol. CellHome page
T. W. Anderson, A. N. Vaughan, and L. P. Cramer
Retrograde Flow and Myosin II Activity within the Leading Cell Edge Deliver F-Actin to the Lamella to Seed the Formation of Graded Polarity Actomyosin II Filament Bundles in Migrating Fibroblasts
Mol. Biol. Cell, November 1, 2008; 19(11): 5006 - 5018.
[Abstract] [Full Text] [PDF]

Home page
 J. Biol. Chem.Home page
M. Iwasa, K. Maeda, A. Narita, Y. Maeda, and T. Oda
Dual Roles of Gln137 of Actin Revealed by Recombinant Human Cardiac Muscle {alpha}-Actin Mutants
J. Biol. Chem., July 25, 2008; 283(30): 21045 - 21053.
[Abstract] [Full Text] [PDF]

Home page
 Proc. Natl. Acad. Sci. USAHome page
M. A. Cejas, W. A. Kinney, C. Chen, J. G. Vinter, H. R. Almond Jr., K. M. Balss, C. A. Maryanoff, U. Schmidt, M. Breslav, A. Mahan, et al.
Thrombogenic collagen-mimetic peptides: Self-assembly of triple helix-based fibrils driven by hydrophobic interactions
PNAS, June 24, 2008; 105(25): 8513 - 8518.
[Abstract] [Full Text] [PDF]

Home page
 Mol. Cell. Biol.Home page
N. S. Tan, G. Icre, A. Montagner, B. B.-t. Heggeler, W. Wahli, and L. Michalik
The Nuclear Hormone Receptor Peroxisome Proliferator-Activated Receptor {beta}/{delta} Potentiates Cell Chemotactism, Polarization, and Migration
Mol. Cell. Biol., October 15, 2007; 27(20): 7161 - 7175.
[Abstract] [Full Text] [PDF]

This Article
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
282/32/23005    most recent
R700020200v1
Right arrow Submit a Letter to Editor
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowRequest Permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Carlier, M.-F.
Right arrow Articles by Pantaloni, D.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Carlier, M.-F.
Right arrow Articles by Pantaloni, D.
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati  
What's this?

HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
 All ASBMB Journals   Molecular and Cellular Proteomics 
 Journal of Lipid Research   ASBMB Today 
Copyright © 2007 by the American Society for Biochemistry and Molecular Biology.
Advertisement
spacer
Advertisement
Advertisement