Final answer:
The presence of β-actin proteins at growth cones is closely associated with actin filament polymerization and cell motility processes such as lamellipodium and filopodia protrusion, and the maturation of focal adhesions.
Step-by-step explanation:
The presence of β-actin proteins at growth cones is accompanied by complex cellular processes that involve the actin cytoskeleton. β-actin plays a crucial role in the polymerization of actin filaments which support cellular movements such as protrusion of the lamellipodium and filopodia. These actin filaments exhibit dynamic behavior, characterized by a non-equilibrium competition between growth and shrinkage, a phenomenon known as treadmilling. Focal adhesions begin as small nascent adhesions at the periphery of the cell and migrate towards the center, maturing as they associate with the retrograde actin flow. These processes are vital for cell motility and the formation of stable cellular structures.