Final answer:
In the active state, integrin dimerization occurs when two receptors bind to form a dimer, leading to activation of their intracellular domains and initiating a cellular response.
Step-by-step explanation:
In the active state of the integrin dimer, conformational changes of the extracellular domain upon ligand binding can propagate through the membrane region of the receptor, leading to activation of the intracellular domain or its associated proteins. Dimerization, the process where two receptors bind to each other to form a dimer, causes the respective intracellular domains to come into close proximity, initiating a downstream cellular response. Within focal adhesions, integrins engage in inside-out signaling, where the contractile forces of the cytoskeleton can activate integrins for matrix binding. This process involves proteins like talin, which connects integrins to the actin cytoskeleton, along with vinculin and paxillin that strengthen the adhesion complex.