Final Answer:
Lamellipodia adhere to a new surface by touching down and sticking with the assistance of integrins, which act as molecular links between the cell and the extracellular matrix, creating a stable anchor through the capture of actin filaments in the cell cortex.
Step-by-step explanation:
During cell movement and adhesion to a new surface, lamellipodia, which are dynamic extensions of the cell membrane, play a crucial role. Lamellipodia are rich in actin filaments and are responsible for the protrusion of the cell's leading edge. As the cell moves, lamellipodia make contact with the new surface, initiating adhesion. This process is facilitated by integrins, transmembrane proteins that act as receptors connecting the extracellular matrix to the cell's cytoskeleton.
Integrins play a vital role in cell adhesion and migration. In the context of protrusion adhering to a new surface, integrins act as the molecular link between the cell and the extracellular matrix of the target surface. Integrins bind to specific ligands in the extracellular matrix, promoting the attachment of the cell to the surface. This attachment is crucial for various cellular processes, including tissue development, wound healing, and immune response.
Additionally, the capture of actin filaments by integrins in the cell cortex creates a stable anchor, reinforcing the adhesion of the lamellipodia to the new surface. This dynamic interplay between lamellipodia, integrins, and the cytoskeleton is essential for cell migration, tissue organization, and overall cellular function.