FIGURE 4.

Integrin signaling pathways

A: integrin inside-out signaling. A key final step of inside-out signaling is the binding of cytosolic adapter protein talin and kindlins. Question marks indicate that the mechanisms remain unclear and require further investigation. B: early phase integrin outside-in signaling, which requires the interaction between Gα₁₃ and Src with the β₃ cytoplasmic domain. Talin dissociation occurs during the early phase outside-in signaling. C: late-phase integrin outside-in signaling, which requires talin reassociation and calpain cleavage of Src binding site in the β₃ tail.