Actin Dynamics and Myosin Function in Cellular Motility

Cellular motility is orchestrated by the dynamic assembly and disassembly of actin filaments coupled to the force-generating activity of myosin motors. Globular actin (G-actin) polymerises into filamentous actin (F-actin), forming branched networks and linear bundles that underpin protrusive and contractile structures. Nucleation factors such as the Arp2/3 complex and formin proteins govern filament architecture, while crosslinking proteins confer mechanical integrity. Myosin II motors assemble into bipolar filaments that slide F-actin arrays to generate contractile forces essential for rear retraction, cytokinesis and tissue morphogenesis. The interplay between actin polymerisation at the leading edge and myosin-driven contraction at the rear establishes polarity and directional movement. Regulation by phosphorylation, small GTPases and phosphoinositide signals ensures rapid reorganisation in response to extracellular cues. This concerted actomyosin machinery underlies processes from immune cell chemotaxis to cancer cell invasion, highlighting its fundamental and translational importance.

Research from Nature Portfolio

Recent studies have revealed how microtubule arrays and actin-binding factors are spatially coordinated during cell division. In mitotic cells, formin proteins and the Arp2/3 complex are selectively localised to regions surrounding spindle poles, generating actin domains that exclude myosin II and direct cleavage furrow ingression. This sorting mechanism ensures precise cytokinetic furrow placement and successful abscission. In parallel, a distinct formin-derived actin meshwork has been identified at the rear cortex of migrating cells. This resilient network, reinforced by crosslinkers and scaffolding proteins, resists contractile stresses and prevents unproductive blebbing. It thereby sustains efficient rear retraction in confined two-dimensional environments and maintains directional persistence. Together, these findings illuminate how specialised actin assemblies and their myosin interactions adapt to diverse mechanical demands in both division and migration.

Actin Dynamics and Myosin Function in Cellular Motility publication trend

The graph below shows the total number of articles in actin dynamics and myosin function in cellular motility across all publications each year (not limited to Nature Index journals).

Technical terms

G-actin: Monomeric form of actin that polymerises into filaments.

F-actin: Filamentous polymer of actin subunits forming cytoskeletal structures.

Arp2/3 complex: Seven-protein assembly that nucleates branched actin networks.

Formin: Family of proteins that nucleate and elongate linear actin filaments.

Myosin II: Motor protein that forms bipolar filaments and generates contractile force on F-actin.

Actomyosin: Contractile system comprising F-actin and myosin motors.

Cortical actin meshwork: Dense network of actin beneath the plasma membrane providing mechanical support.

Myosin heavy chain kinase: Enzyme that phosphorylates myosin tails, regulating filament assembly.

References

1. Microtubule dependent sorting of actin-binding proteins in mitosis. Scientific Reports (2024).
2. A resilient formin-derived cortical actin meshwork in the rear drives actomyosin-based motility in 2D confinement. Nature Communications (2015).
3. Suggesting Dictyostelium as a Model for Disease-Related Protein Studies through Myosin II Polymerization Pathway. Cells (2024).
4. Differential Roles of Actin Crosslinking Proteins Filamin and α-Actinin in Shear Flow-Induced Migration of Dictyostelium discoideum. Frontiers in Cell and Developmental Biology (2021).
5. Myosin Heavy Chain Kinase from Developed Dictyostelium cells Purification and Characterization. Journal of Biological Chemistry (1989).