... conformationalchange in the extracellular domain, leading to anincrease in affinity, thereby promoting integrin–ligandinteractions [2]. In turn, clustering of integrins gene-rates a series of intracellular ... critical role for aIIbb3 in promoting platelet lamellipodia formationon CRP, thrombin and on fibrinogen, but that out-side -in signalling by the integrin is not required for lamellipodia formation ... buffered saline and blocking withdenatured BSA (5 mgÆmL)1) for 1 h. Platelets were exposedto coverslips for 45 min, before fixing, staining where neces-sary, and mounting as described in McCarty...