Disease relevance of F2

• A recombinant murine meizothrombin precursor, prothrombin R157A/R268A, inhibits thrombosis in a model of acute carotid artery injury [1].
• This PB1-F2 protein will enhance the mortality rate of the virus by increasing the likelihood of a secondary bacterial infection, which is the primary cause of death to a patient infected with Influenza A [2].
• The PB1-F2 protein of Influenza A virus: increasing pathogenicity by disrupting alveolar macrophages [2].
• Incomplete embryonic lethality and fatal neonatal hemorrhage caused by prothrombin deficiency in mice [3].
• Prothrombin has proven to be a harmful contaminant in factor IX cocktails that have been administered to humans in the treatment of hemophilia B [4].

High impact information on F2

• There were higher levels of F2 mRNA (encoding prothrombin) as well as prothrombin and thrombin protein in liver of C3-/- mice compared to C3+/+ mice [5].
• Coagulation factor V is a critical cofactor for the activation of prothrombin to thrombin, the penultimate step in the generation of a fibrin blood clot [6].
• Hematological analysis of TAFI-deficient mice did not show any major differences including plasma fibrinogen level, prothrombin time, and activated partial thromboplastin time [7].
• One site apparently recognizes both Factors IX and IXa, but not Factor X, Factor Xa, prothrombin, or thrombin [8].
• A Ca++ activated serine protease (LOPAP) could be responsible for the haemorrhagic syndrome caused by the caterpillar Lonomia obliqua. L obliqua Prothrombin Activator Protease [9].

Chemical compound and disease context of F2

• Warfarin treatment did not affect bone growth, overall weight gain, or serum calcium and phosphorus levels, and, because of the concurrent administration of vitamin K, prothrombin times and hematocrits were normal [10].
• In endotoxin-induced experimental disseminated intravascular coagulation in rats, norathyriol (50-100 mg kg-1, i.p.) prevented the decrease in platelet counts and fibrinogen, and the prolongation of plasma prothrombin time [11].

Biological context of F2

• Characterization of the cDNA coding for mouse prothrombin and localization of the gene on mouse chromosome 2 [12].
• The complete prothrombin cDNA is 1,987 bp in length [excluding the poly(A) tail] and codes for 18 bp of 5' untranslated sequence, an open reading frame coding for 618 amino acids, a stop codon, and a 3' untranslated region of 112 bp followed by a poly(A) tail [12].
• A series of overlapping cDNAs coding for mouse prothrombin (coagulation factor II) have been isolated and the composite DNA sequence has been determined [12].
• The conversion of prothrombin (FII) to the serine protease, thrombin (FIIa), is a key step in the coagulation cascade because FIIa triggers platelet activation, converts fibrinogen to fibrin, and activates regulatory pathways that both promote and ultimately suppress coagulation [13].
• The predicted posttranslational modifications, including disulfide bonds, N-glycosylation, phosphorylation, and sulfation, in pseutarin C are significantly different compared with bovine factor V. Thus, our data demonstrate that the nonenzymatic subunit of group C prothrombin activators is structurally similar to mammalian FV [14].

Anatomical context of F2

• Purified coagulation factors VII, X, and V and prothrombin were perfused at a wall shear rate of 100 s-1 through a flow chamber containing a coverslip covered with matrix of cultured human umbilical vein endothelial cells [15].
• Quantitative reverse transcription polymerase chain reaction demonstrated the expression of prothrombin mRNA in myotubes, but not in myoblasts, of primary, C2, and G8 muscle cells [16].
• Prothrombin significantly inhibited endothelial cell tube formation in vitro at 10 microg/ml [17].
• Protein C can be obtained from human blood plasma; however, there are other coagulant proteins in blood, including prothrombin (factor II), which is present in relatively large amounts and is one of the most active components [4].
• We have developed and applied such procedures to the determination of prothrombin messages in skeletal muscle cells during development [18].

Associations of F2 with chemical compounds

• Chymotrypsin digestion of prothrombin and isolation on QAE-Sephadex of the peptide representing amino-terminal residues 1-44 of prothrombin further localized the antigenic site recognized by the monoclonal antibody to the highly conserved gamma-carboxyglutamic acid-containing domain [19].
• We monitored neuromuscular behavior, correlated with acetylcholinesterase and silver nitrate histochemistry at endplates, for changes in the timecourse of in vivo synapse elimination and assayed both thrombin activity and prothrombin expression in developing muscle [20].
• Processing was facilitated by CaCl2 but prevented by a thrombin inhibitor and did not occur in prothrombin-depleted plasma [21].
• Recent experiments showing that thrombin is released from myotubes in culture under the influence of acetylcholine suggest that locally-synthesized prothrombin may be the source of this Hebbian synaptic interaction [18].
• Following protein adsorption to the column, prothrombin was washed out using a sodium phosphate buffer containing 2 mM imidazole and protein C was recovered with 15 mM imidazole in the buffer [4].

Physical interactions of F2

• All three antibodies bound to the light chain of protein C on immunoblots and also bound to the homologous proteins factor X and prothrombin in solid-phase radioimmunoassays [22].
• Differently from platelets, B16F10-assembled prothrombinase complex was inhibited by prothrombin fragment 1 but not by fragment 2 [23].
• The three-dimensional structure of prothrombin predicted by homology modeling also revealed that the prothrombin fragment 1 and the catalytic domain structures are well conserved except for the insertion of an extra 7-amino-acid loop in the connecting region (CR) between the Gla and kringle I domain of fragment 1 [24].

Enzymatic interactions of F2

• The PCA was shown to have direct prothrombin cleaving activity (prothrombinase) by ELISA and immunofluorescence staining using the mAb 3D4 [25].

Regulatory relationships of F2

• The finding of robust thrombin receptor expression before prothrombin mRNA was detected raises the question of whether other proteases or peptide ligands can activate the thrombin receptor [26].
• In addition, naringin markedly suppressed TNF-alpha and normalized the activated states of blood coagulation factors such as prothrombin time, fibrinogen concentration and platelet numbers caused by infection [27].

Other interactions of F2

• In contrast to the thrombin receptor, prothrombin mRNA was limited to the embryonic liver and was not detected until E12.5, well after the onset of receptor expression. mRNA for tissue factor, one important trigger for thrombin generation in the adult, was detected in embryonic epithelia from E9.5-12 [26].
• The prothrombin locus lies on mouse chromosome 2, 1.8 +/- 1.3 map units proximal to the catalase locus [12].
• Anti-TF or anti-FVII/VIIa (but not inhibited factor IXa) delayed the burst in thrombin production by gel-filtered platelets suspended in prothrombin and CVX by 14 min and 40 min, respectively [28].
• As compared with WT mice, MT (-/-) mice revealed significant prolongation of prothrombin and activated partial thromboplastin time, a significant increase in the levels of fibrinogen and fibrinogen/fibrin degradation products, and a significant decrease in activated protein C, after LPS treatment [29].
• Factor IX is proposed to have branched off early on, followed by protein C and prothrombin and finally factors VII and X [30].

Analytical, diagnostic and therapeutic context of F2

• We examined the expression of thrombin receptor, prothrombin, and tissue factor by in situ hybridization in mouse development [26].
• Partial characterization of vertebrate prothrombin cDNAs: amplification and sequence analysis of the B chain of thrombin from nine different species [31].
• Reverse transcription-polymerase chain reaction (PCR) showed that neonatal muscle was a source of local prothrombin, with peak expression during the first week after birth [20].
• The changes in mRNA levels of the three genes after denervation indicated that these genes were regulated in a innervation-dependent manner and that nerve activity may play an important regulatory role in the expression of prothrombin, ThR, and PN-1 [32].
• Homologous human blood protein separation using immobilized metal affinity chromatography: protein C separation from prothrombin with application to the separation of factor IX and prothrombin [4].

References