Thrombomodulin functions as a
cofactor in the
thrombin-induced activation of
protein C in the
anticoagulant pathway by forming a 1:1 stoichiometric complex with thrombin. This raises the speed of protein C activation thousandfold. Thrombomodulin-bound thrombin has procoagulant effect at the same time by inhibiting fibrinolysis by cleaving
thrombin-activatable fibrinolysis inhibitor (TAFI, aka carboxypeptidase B2) into its active form. Thrombomodulin is a
glycoprotein on the surface of endothelial cells that, in addition to binding thrombin, regulates
C3b inactivation by factor I. Mutations in the thrombomodulin gene (THBD) have also been reported to be associated with
atypical hemolytic-uremic syndrome (aHUS). The
antigen described as BDCA-3 has turned out to be identical to thrombomodulin. Thus, it was revealed that this molecule also occurs on a very rare (0.02%) subset of human
dendritic cells called MDC2. Its function on these cells is unknown. == Interactions ==