Agonist-induced inside-out integrin signaling system reconstituted in CHO cells. (A) CHO cells normally do not respond to PMA. CHO cells overexpressing integrin-αIIbβ3, PKC-α, and talin responded to PMA, resulting in αIIbβ3 activation. (B) CHO cells do not respond to thrombin or related peptide agonists, CHO cells overexpressing αIIbβ3, PAR, and talin responded to thrombin receptor peptide agonist, leading to activation of Rap1, formation of a Rap1-RIAM-talin ternary complex, and αIIbβ3 activation.