Reactome: A Curated Pathway Database

Activated protein C cleaves factor Va to factor Vi intermediate form (R-HSA-141026) [Homo sapiens]


Activated protein C cleaves peptide bonds in activated factor V (factor Va), converting it to an inactive form (factor Vi). APC proteolysis involves cleavage of the factor Va heavy chain at Arg-334 (306 if signal peptide is not included) and Arg-534 (506 with no signal peptide) (Nicolaes et al. 1985). Most factor Va molecules are initially cleaved at Arg-534, yielding a partially active intermediate, followed by complete inactivation through cleavage at Arg-334 (Kalafatis et al. 1994). Factor Xa inhibits Arg-534 cleavage but this effect is mitigated by Protein S (Norstrom et al. 2006). A mutation of the APC cleavage sites in Fv at Arg-534Gln a.k.a. FVLeiden is the most common identifiable hereditary risk factor for venous thrombosis among Caucasians (Camire 2011).

Additional Information
Compartment extracellular region , plasma membrane
Literature References
pubMedId Title Journal Year
2538457 The roles of protein C and thrombomodulin in the regulation of blood coagulation J Biol Chem 1989