What Molecular Mechanisms Regulate Lamellipodia and Filopodia?
The formation and function of lamellipodia and filopodia are regulated by various signaling pathways and molecular players. Some key regulators include:
Rho GTPases: These are small GTP-binding proteins, including Rac1 and Cdc42, that coordinate actin dynamics. Rac1 primarily regulates lamellipodia formation, while Cdc42 is essential for filopodia formation. Actin-Binding Proteins: Proteins like Arp2/3 complex and formins nucleate and elongate actin filaments, respectively, driving the formation of these protrusions. Integrins: These transmembrane receptors mediate cell-ECM interactions, providing traction for cell movement. They are crucial for the attachment and signaling required for lamellipodia and filopodia dynamics. Ena/VASP Proteins: These proteins regulate actin filament elongation and are involved in the formation of filopodia by promoting the bundling of actin filaments.
