Official Full Name
coagulation factor V (proaccelerin, labile factor)
Factor V (pronounced factor five) is a protein of the coagulation system, rarely referred to as proaccelerin or labile factor. In contrast to most other coagulation factors, it is not enzymatically active but functions as a cofactor. Deficiency leads to predisposition for hemorrhage, while some mutations (most notably factor V Leiden) predispose for thrombosis. Coagulation factor V is a cofactor that participates with factor Xa to activate prothrombin to thrombin. Factor Va is composed of a heavy chain and a light chain, noncovalently bound. The interaction between the two chains is calcium-dependent. Thrombin activates factor V proteolytically to the active cofactor, factor Va (formation of a heavy chain at the N-terminus and a light chain at the C-terminus). Sulfation is required for efficient thrombin cleavage and activation and for full procoagulant activity. Defects in F5 are the cause of Owren parahemophilia which is an hemorrhagic diastesis. Defects in F5 are the cause of resistance to activated protein C (APCR). APCR is a form of thrombophilia. The APCR mutation is found in about 5% of the population which suggest that a slight thrombotic tendency may confer some advantage in fetal implantation.
F5; FVL; PCCF; coagulation factor V; factor V Leiden; OTTHUMP00000032547; OTTHUMP00000032548; proaccelerin, labile factor; activated protein c cofactor; coagulation factor V jinjiang A2 domain; coagulation factor V (proaccelerin, labile factor); wu:fd21h06; si:bz20i5.3; factor V