Filopodia protrusion is aided by actin filament cross-linking, which gives the structure the strength required to push against the compressive force of the plasma membrane . Bundle stiffness increases with the number of bundled filaments and so contributes to the overall length of the filopodium . Filament bundling results from crosslinking proteins, many of which co-localize at the base of filopodia and work in concert to produce crosslinked filaments … Read more…