Integrin functions are controlled by regulating their affinity for ligand, and 
by the efficient recycling of intact integrins through endosomes. Here we 
demonstrate that the Kindlin-binding site in the β1-integrin cytoplasmic domain 
serves as a molecular switch enabling the sequential binding of two 
FERM-domain-containing proteins in different cellular compartments. When β1 
integrins are at the plasma membrane, Kindlins control ligand-binding affinity. 
However, when they are internalized, Kindlins dissociate from integrins and 
sorting nexin 17 (SNX17) is recruited to free β1-integrin tails in early 
endosomes to prevent β1-integrin degradation, leading to their recycling back to 
the cell surface. Our results identify SNX17 as a β1-integrin-tail-binding 
protein that interacts with the free Kindlin-binding site in endosomes to 
stabilize β1 integrins, resulting in their recycling to the cell surface where 
they can be reused.