Filopodia rotation and twisting

Active surface protrusions emanating all from cells

In our TCB review we have discussed the many different functions of filopodia and their mechanistic function. Filopodia operate in most cells and facilitate communication, organisation, sensing, probing, and motility.

Filopodia rotate and twist during retraction. By tracking tracer beads linked to the side of the filopodium through vitronectin we discovered that the internal actin bundle twists or rotates which also led to buckling. See Nat. Commun. 2022.

Buckling of a filopodium during retraction. Image shows four time points. See PNAS 2015.

Active Matter Dynamics & Filopodia Mechanics: Rotation Twisting and Force Generation

We investigate how actin-driven filopodia generate forces and explore the cellular environment. These slender membrane protrusions connect cytoskeletal dynamics inside the cell with mechanical interactions at its surface.

Our work combines optical tweezers, three-dimensional confocal microscopy and theoretical modeling to relate filopodial motion to actin-bundle organization. We study rotation, twisting, helical buckling and retraction, and examine how these processes contribute to force generation.

Our studies have shown that filopodia can rotate and coil as an active matter through active twisting of their actin shaft, and that helical buckling of actin can generate traction. These findings motivate a view of filopodia as dynamic mechanical structures rather than passive cellular antennae.

We are interested in how this mechanical activity contributes to environmental exploration and cell–environment interactions.

 

Confocal 3D images showing how individual filopodia from pancreatic cancer cells rotate, twist and perform beautiful buckles.