Journal ArticleDOI
Two distinct actin networks drive the protrusion of migrating cells
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TLDR
Computational analysis of fluorescent speckle microscopy movies of migrating epithelial cells revealed this process is mediated by two spatially colocalized but kinematically, kinetically, molecularly, and functionally distinct actin networks.Abstract:
Cell migration initiates by extension of the actin cytoskeleton at the leading edge. Computational analysis of fluorescent speckle microscopy movies of migrating epithelial cells revealed this process is mediated by two spatially colocalized but kinematically, kinetically, molecularly, and functionally distinct actin networks. A lamellipodium network assembled at the leading edge but completely disassembled within 1 to 3 micrometers. It was weakly coupled to the rest of the cytoskeleton and promoted the random protrusion and retraction of the leading edge. Productive cell advance was a function of the second colocalized network, the lamella, where actomyosin contraction was integrated with substrate adhesion.read more
Citations
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Journal ArticleDOI
Actin Dynamics: Growth from Dendritic Branches
TL;DR: The dendritic nucleation model was devised to explain the cycle of actin dynamics resulting in actin filament network assembly and disassembly in two contexts--at the leading edge of motile cells and in the actin comet tails of intracellular pathogenic bacteria and viruses.
Journal ArticleDOI
Adhesion-dependent and Contractile Ring-independent Equatorial Furrowing during Cytokinesis in Mammalian Cells
TL;DR: Direct evidence is provided for adhesion-dependent, contractile ring-independent equatorial furrowing in mammalian cells and the importance of substrate adhesion for cytokinesis is demonstrated.
Journal ArticleDOI
Coupling of β 2 integrins to actin by a mechanosensitive molecular clutch drives complement receptor-mediated phagocytosis
TL;DR: Macrophages use tyrosine kinase signalling to build a mechanosensitive, talin- and vinculin-mediated, focal adhesion-like molecular clutch, which couples integrins to cytoskeletal forces to drive particle engulfment.
Journal ArticleDOI
Rac1-null Mouse Embryonic Fibroblasts Are Motile and Respond to Platelet-derived Growth Factor
TL;DR: It is indicated that lamellipodia formation is not required for cell motility, and PDGF-induced chemotaxis can occur in the absence of both lamellIPodia and Rac1, to refine the understanding of the functions of Rac1.
Journal ArticleDOI
Filopodial actin bundles are not necessary for microtubule advance into the peripheral domain of Aplysia neuronal growth cones.
TL;DR: Filopodial actin bundles guide microtubule assembly in the growth cone peripheral (P) domain and retrograde actin-network flow simultaneously transports microtubules rearward; however, their presence ensures radial distribution of micro Tubule-end position in the P domain and facilitates micro tubule transport by retrograde flow.
References
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Journal ArticleDOI
Cell Migration: A Physically Integrated Molecular Process
TL;DR: The authors are grateful for financial support from the National Institutes of Health (grants GM23244 and GM53905), and to very helpful comments on the manuscript from Elliot Elson, Vlodya Gelfand, Paul Matsudaira, Julie Theriot, and Sally Zigmond.
Journal ArticleDOI
Cellular Motility Driven by Assembly and Disassembly of Actin Filaments
Thomas D. Pollard,Gary G. Borisy +1 more
TL;DR: A core set of proteins including actin, Arp2/3 complex, profilin, capping protein, and ADF/cofilin can reconstitute the process in vitro, and mathematical models of the constituent reactions predict the rate of motion.
Journal ArticleDOI
The interaction of Arp2/3 complex with actin: Nucleation, high affinity pointed end capping, and formation of branching networks of filaments
TL;DR: It is shown that Arp2/3 complex purified from Acanthamoeba caps the pointed ends of actin filaments with high affinity and increases the critical concentration for polymerization at the pointed end from 0.6 to 1.0 microM.
Journal ArticleDOI
Dissecting Temporal and Spatial Control of Cytokinesis with a Myosin II Inhibitor
Aaron F. Straight,Amy Cheung,John Limouze,Irene A. Chen,Nicholas J. Westwood,James R. Sellers,Timothy J. Mitchison +6 more
TL;DR: It is shown that exit from the cytokinetic phase of the cell cycle depends on ubiquitin-mediated proteolysis and continuous signals from microtubules are required to maintain the position of the cleavage furrow, and these signals control the localization of myosin II independently of other furrow components.
Journal ArticleDOI
Actions of cytochalasins on the organization of actin filaments and microtubules in a neuronal growth cone.
Paul Forscher,Stephen J. Smith +1 more
TL;DR: Results suggest that actin normally polymerizes at the leading edge and then flows rearward at a rate between 3-6 microns/min, which is consistent with their being secondary to effects of CB on lamellar F-actin.
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