Myosin-X is an unconventional myosin that undergoes intrafilopodial motility

  title={Myosin-X is an unconventional myosin that undergoes intrafilopodial motility},
  author={Jonathan S. Berg and Richard E. Cheney},
  journal={Nature Cell Biology},
Filopodia are thin cellular protrusions that are important in cell motility and neuronal growth cone guidance. The actin filaments that make up the core of a filopodium undergo continuous retrograde flow towards the cell body. Surface receptors or particles can couple to this retrograde flow and can also move forward to the tips of filopodia, although the molecular basis of forward transport is unknown. We report here that myosin-X (Myo10 or M10), the founding member of a novel class of myosins… 

Activated full-length myosin-X moves processively on filopodia with large steps toward diverse two-dimensional directions

Results suggest that the lever-arm of full-length myosin-X is flexible enough to processively steps on different actin filaments within the actin bundles of filopodia.

Imaging Myosin-X at the Single-Molecule Level Reveals a Novel Form of Motility in Filopodia

A novel form of motility at or near the single-molecule level in living cells wherein extremely faint particles of Myo10 move in a rapid and directed fashion towards the filopodial tip is revealed.

Myosin-X: a MyTH-FERM myosin at the tips of filopodia

Exciting new studies have begun to reveal the structure and single-molecule properties of this intriguing myosin, as well as its mechanisms of regulation and induction of filopodia.

A Combination of Diffusion and Active Translocation Localizes Myosin 10 to the Filopodial Tip*

A model by which myosin 10 rapidly targets to the filopodial tip via a sequential reduction in dimensionality is proposed by which molecules first undergo rapid diffusion within the three-dimensional volume of the cell body, then exhibit periods of slower two-dimensional diffusion in the plane of the plasma membrane.

Myosin-X is a molecular motor that functions in filopodia formation

It is shown that siRNA-mediated knockdown of Myo10 in HeLa cells leads to a dramatic loss of dorsal filopodia, and additional experiments indicate that it acts downstream of Cdc42 and can promote filopadia in the absence of VASP proteins.

Myosin-X Induces Filopodia by Multiple Elongation Mechanism*

A model of myosin-X-induced filopodia protrusion is proposed and the majority of the fluorescence spots showed two-step photobleaching, suggesting that the moving myosIn-X is a dimer.

Myosin X transports Mena/VASP to the tip of filopodia.

  • H. TokuoM. Ikebe
  • Biology
    Biochemical and biophysical research communications
  • 2004

Myosin-X recruits lamellipodin to filopodia tips

Using GFP-Trap and BioID approaches combined with mass spectrometry, this work identifies lamellipodin (RAPH1) as a novel MyO10 cargo and reports that the FERM domain of MYO10 is required for RAPH1 localization and accumulation at filopodia tips.

Filopodia act as phagocytic tentacles and pull with discrete steps and a load-dependent velocity

This study used an optical trap and interferometric particle tracking with nanometer precision to measure the three-dimensional dynamics of macrophage filopodia, which were not attached to flat surfaces and found that they act as cellular tentacles: a few seconds after binding to a particle, filophodia retract and pull the bound particle toward the cell.



Actin based motility on retraction fibers in mitotic PtK2 cells.

Surprisingly, movement after cytochalasin withdrawal was often outward, indicating a local reversal of cortical polarity, and the implications for the mechanism and polarity of actin dependent motility is discussed.

Myosin dynamics in live Dictyostelium cells.

GFP-myosin is concentrated in the cleavage furrow during cytokinesis and in the posterior cortex of migrating cells, and Surprisingly, GFP-Myosin concentration increases transiently in the tips of retracting pseudopods, suggesting that conventional myosin may play an important role in the dynamics of pseudopod as well as filopodias, lamellipodia, and other cellular protrusions.

Extension of filopodia by motor-dependent actin assembly.

A motor protein powers both the extension and retraction of filopodia in advancing cells and axonal growth cones, including actin polymerization and osmotic swelling.

Regulated tyrosine phosphorylation at the tips of growth cone filopodia

It is demonstrated that tyrosine-phosphorylated protein can be concentrated at the barbed ends of actin filaments in a context other than an adherens junction, an association between changes in phosphorylation and filament dynamics is indicated, and evidence for tyrosines phosphorylated as a signaling mechanism in the filopodium that can respond to environmental cues controlling growth cone dynamics is provided.

Regulated Actin Cytoskeleton Assembly at Filopodium Tips Controls Their Extension and Retraction

Observing the movement of fiduciary marks on actin filaments in growth cones of a neuroblastoma cell line found that filopodium extension and retraction are governed by a balance between the rate of actin cytoskeleton assembly at the tip and retrograde flow.