Figure 3.

Activation of PAR1 and PAR2 by the TF pathway. In the transient TF-VIIa-Xa complex, Xa is an efficient activator of PAR1 and PAR2. Downstream TF-dependent coagulation occurs after dissociation of Xa from this ternary complex. This essential procoagulant event results in less efficient PAR signaling because either TF-VIIa or free Xa is less capable of PAR activation than the TF-VIIa-Xa complex. Adapted with permission from Ruf and Riewald [5]. PAR, protease activated receptor; TF, tissue factor; VIIa, activated factor VII; Xa, activated factor X.