Figure 8.

Schematic diagram for the recruitment of I-BAR domain proteins and actin filaments by GM1 aggregates. The positive and negative curvatures at the outer and inner leaflets are induced by a GM1 aggregate. Consequently, I-BAR domain proteins are attracted to the negative curvature at the inner leaflet of a cell membrane. The I-BAR domain proteins would further bend the membrane, while activating the actin nucleation machinery. The nucleation of actin filaments would drive a membrane protrusive growth, elongating the membrane protrusion.