Homozygous loss of mouse tetraspanin CD82 enhances integrin αIIbβ3 expression and clot retraction in platelets.

Integrin αIIbβ3 is critical for platelet-mediated blood clotting. Tetraspanins are well-established regulators of integrins and genetic loss of tetraspanin CD151 or TSSC6 in mice leads to increased bleeding due to inadequate integrin αIIbβ3 outside-in signaling. Conversely, mild but enhanced integrin αIIbβ3 activation and hyperaggregation is observed in CD9 and CD63 null mice respectively.