FIGURE 7:

Model. Coalescence of VASP into leading edge clusters arises from small preexisting lamellipodin clusters. The interaction between VASP and Lpd at clusters is mediated through multivalent interactions between EVH1 domains (VASP) and short FPPPP proline motifs (Lpd) that require membrane tethering and dimerization of Lpd. The assembly of VASP clusters involve Lpd and free barbed ends of actin filaments at the leading edge, which can protrude into long filopodia or disassemble through size-dependent splitting of VASP into the cytoplasm.