Fig. 4.

Membrane protrusion coalescence. a In the case of a single protrusion, membrane tension functions to keep the plasma membrane closely associated with the underlying actin bundle. b If a second protrusion forms too close to the first, tension will force the actin bundles to coalesce into a single protrusion. c Two adjacent protrusions are stabilized by the presence of high levels of membrane-cytoskeleton adhesion (provided by red linker molecules), which serves to counter coalescence