Filopodia Dynamics in Cell Motility and Adhesion

Filopodia are slender, finger-like membrane protrusions composed of parallel bundles of actin filaments that extend from the cell surface to probe the extracellular environment, guide directional migration and mediate early adhesion events. Dynamic regulation of filopodial assembly involves the coordinated action of actin polymerisation factors, such as formins and Ena/VASP proteins, membrane-curvature sensors including I-BAR domain proteins and motor proteins like myosin X. Mechanical forces generated at the filopodial base by non-muscle myosin IIA and transmitted along the actin core control both protrusion stability and engagement with extracellular matrix ligands via integrins. Assembly and retraction cycles of filopodia not only steer cell motility in developmental, immune and pathological contexts but also nucleate nascent adhesion sites that mature into focal adhesions, thereby linking environmental sensing with traction generation. Recent advances in live-cell imaging, reconstitution assays and in vivo genetic models highlight the multifaceted roles of filopodia in processes ranging from tissue morphogenesis and angiogenesis to cancer invasion and neuronal pathfinding. Understanding these dynamics reveals fundamental principles of cell–matrix interactions and offers avenues for therapeutic modulation of cell migration.

Research from Nature Portfolio

Recent studies have elucidated the role of centripetal tension in filopodia adhesion, demonstrating that myosin IIA at the filopodial base generates pulling forces transmitted through formin-decorated actin to the tip, essential for stable extracellular matrix engagement. Linked investigations in genetic mouse models deficient in myosin X reveal a profound reduction in endothelial filopodia during developmental angiogenesis, underscoring Myo10’s indispensability for filopodial assembly in vivo and its broader impact on tissue morphogenesis. High-resolution structural and biophysical analyses further characterise the unique mechanochemical properties of myosin X dimers, which exhibit enhanced processivity and larger step sizes on bundled actin tracks, optimising filopodia extension under varying cytoskeletal geometries.

Filopodia Dynamics in Cell Motility and Adhesion publication trend

The graph below shows the total number of articles in filopodia dynamics in cell motility and adhesion across all publications each year (not limited to Nature Index journals).

Technical terms

Actin polymerisation: Process by which actin monomers assemble into filaments that generate protrusive force.

Formins: Actin-nucleating proteins that facilitate elongation of unbranched filaments within filopodia cores.

Myosin IIA: Non-muscle motor protein generating contractile forces at the base of filopodia to support adhesion.

Myo10 (myosin X): Unconventional motor that targets filopodial tips and regulates protrusion dynamics through processive movement on actin bundles.

I-BAR domain: Membrane-binding module that senses and induces curvature to initiate filopodial protrusions.

Phosphoinositides: Phosphorylated lipids localising to filopodial tips, modulating recruitment of signalling and adhesion proteins.

References

1. Filopodia In Vitro and In Vivo. Annual Review of Cell and Developmental Biology (2023).
2. Myosin IIA and formin dependent mechanosensitivity of filopodia adhesion. Nature Communications (2019).
3. The myosin X motor is optimized for movement on actin bundles. Nature Communications (2016).
4. Myosin-X knockout is semi-lethal and demonstrates that myosin-X functions in neural tube closure, pigmentation, hyaloid vasculature regression, and filopodia formation. Scientific Reports (2017).
5. Tunnelling nanotube formation is driven by Eps8/IRSp53‐dependent linear actin polymerization. The EMBO Journal (2023).
6. Filopodome Mapping Identifies p130Cas as a Mechanosensitive Regulator of Filopodia Stability. Current Biology (2019).