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Internetwork competition for monomers governs actin cytoskeleton organization

Nature Reviews Molecular Cell Biology volume 17, pages 799–810 (2016)Cite this article

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Abstract

Cells precisely control the formation of dynamic actin cytoskeleton networks to coordinate fundamental processes, including motility, division, endocytosis and polarization. To support these functions, actin filament networks must be assembled, maintained and disassembled at the correct time and place, and with proper filament organization and dynamics. Regulation of the extent of filament network assembly and of filament network organization has been largely attributed to the coordinated activation of actin assembly factors through signalling cascades. Here, we discuss an intriguing model in which actin monomer availability is limiting and competition between homeostatic actin cytoskeletal networks for actin monomers is an additional crucial regulatory mechanism that influences the density and size of different actin networks, thereby contributing to the organization of the cellular actin cytoskeleton.

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Figure 1: Functionally diverse F-actin networks in mammalian and fission yeast cells.
Figure 2: Classic model of F-actin network regulation.
Figure 3: Disassembly of F-actin networks releases G-actin that accumulates in remaining networks.
Figure 4: Updated model of F-actin homeostasis including internetwork competitive crosstalk.

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Acknowledgements

The authors thank P. McCall (University of Chicago, Illinois, USA) and members of the Kovar laboratory, including J. Winkelman, J. Christensen and T. Burke for discussions and comments. Work on actin cytoskeleton regulation in the Kovar laboratory is supported by US National Institutes of Health grant R01 GM079265. C.S. has also been supported in part by the US Department of Defence and the US Army Research Laboratory's Army Research Office through a multidisciplinary university research initiative (MURI) grant, number W911NF1410403.

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  1. Cristian Suarez and David R. Kovar are at the Department of Molecular Genetics and Cell Biology, The University of Chicago.,

    Cristian Suarez & David R. Kovar

  2. David R. Kovar is also at the Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, Illinois 60637, USA.,

    David R. Kovar

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Suarez, C., Kovar, D. Internetwork competition for monomers governs actin cytoskeleton organization. Nat Rev Mol Cell Biol 17, 799–810 (2016). https://doi.org/10.1038/nrm.2016.106

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