A continuum model of actin waves in Dictyostelium discoideum.
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TLDR
A model of actin waves in PTEN-deficient Dictyostelium discoideum is developed by deriving an approximation of the dynamics of discrete actin filaments and combining it with a signaling pathway that controls filament branching.Abstract:
Actin waves are complex dynamical patterns of the dendritic network of filamentous actin in eukaryotes. We developed a model of actin waves in PTEN-deficient Dictyostelium discoideum by deriving an approximation of the dynamics of discrete actin filaments and combining it with a signaling pathway that controls filament branching. This signaling pathway, together with the actin network, contains a positive feedback loop that drives the actin waves. Our model predicts the structure, composition, and dynamics of waves that are consistent with existing experimental evidence, as well as the biochemical dependence on various protein partners. Simulation suggests that actin waves are initiated when local actin network activity, caused by an independent process, exceeds a certain threshold. Moreover, diffusion of proteins that form a positive feedback loop with the actin network alone is sufficient for propagation of actin waves at the observed speed of . Decay of the wave back can be caused by scarcity of network components, and the shape of actin waves is highly dependent on the filament disassembly rate. The model allows retraction of actin waves and captures formation of new wave fronts in broken waves. Our results demonstrate that a delicate balance between a positive feedback, filament disassembly, and local availability of network components is essential for the complex dynamics of actin waves.read more
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References
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Journal ArticleDOI
Molecular Mechanisms Controlling Actin Filament Dynamics in Nonmuscle Cells
TL;DR: How motile cells regulate actin filament assembly at their leading edge is reviewed, including how Arp2/3 complex is incorporated into the network, and new filaments are capped rapidly, so that activated Arp1/2 complex must be supplied continuously to keep the network growing.
Journal ArticleDOI
Rac Activation and Inactivation Control Plasticity of Tumor Cell Movement
Victoria Sanz-Moreno,Gilles Gadea,Jessica Ahn,Hugh Paterson,Pierfrancesco Marra,Sophie Pinner,Erik Sahai,Christopher J. Marshall +7 more
TL;DR: It is shown that mesenchymal-type movement in melanoma cells is driven by activation of the GTPase Rac through a complex containing NEDD9, a recently identified melanoma metastasis gene, and DOCK3, a Rac guanine nucleotide exchange factor.
Journal ArticleDOI
A nucleator arms race: cellular control of actin assembly
TL;DR: The Spire, cordon-bleu and leiomodin nucleators have revealed new ways of overcoming the kinetic barriers to actin polymerization.
Journal ArticleDOI
Cdc42 - the centre of polarity
TL;DR: It is now clear that many features of the molecular mechanisms controlling polarization are conserved in all eukaryotic cells, including Cdc42, a small GTPase of the Rho family.
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Tumor suppressor PTEN mediates sensing of chemoattractant gradients.
Miho Iijima,Peter N. Devreotes +1 more
TL;DR: Results suggest that specific phosphoinositides direct actin polymerization to the cell's leading edge and regulation of PTEN through a feedback loop plays a critical role in gradient sensing and directional migration.