Fig. 2. Antagonism between Ena/VASP proteins and capping protein regulates lamellipodial protrusion and whole cell motility. Elevated Ena/VASP activity at the leading edge antagonizes capping protein activity, resulting in longer less branched filaments. This leads to higher lamellipodial protrusion velocity but decreased persistence. Conversely, reduced Ena/VASP activity at the leading edge results in shorter, more highly branched networks of actin filaments. This results in higher lamellipodial persistence and leads to faster whole cell migration speeds despite decreased lamellipodial protrusion velocity.