Profilin promotes lamellipodium protrusion by tuning the antagonistic activities of capping protein and VASP.

Profilin enhances lamellipodium protrusion by regulating the balance between capping protein and VASP, crucial for actin network formation in cell migration.

• Why it matters: Understanding how actin filament networks are assembled is vital for insights into cell movement and related processes, yet the molecular regulation remains incomplete.
• What they did: Using genome editing, the study examined interactions among profilin, Arp2/3 complex, capping protein, and VASP in Dictyostelium discoideum, revealing profilin’s role in promoting Arp2/3 activity and modulating VASP and CP antagonism.
• The result: Profilin acts as a master regulator, differentially controlling VASP and CP, and mathematical models suggest competition for recruitment at lamellipodial edges, advancing understanding of actin-driven protrusions.