126.5A). The presence, source, and function of a soluble form of alternatively spliced TF in blood have also been subjects of controversy [124–127]. In addition, tissue factor and coagulation proteases contribute to the many cellular responses via activation of protease activated receptors. Tissue factor (TF) is the main physiological initiator of blood coagulation and its activity is regulated by a specific inhibitor known as Tissue factor pathway inhibitor (TFPI). Tissue factor pathway inhibitor-2 (TFPI-2) is a 32 kDa matrix-associated Kunitz-type serine proteinase inhibitor consisting of a short amino-terminal region,three tandem Kunitz-type domains and a positively charged carboxy-terminal tail. Similarly, calcium is also an essential component for efficient complex formation [21]. The linkage of carbohydrates to the TF backbone was presumed to be via asparagine. 3. The wide spectrum of activities of these molecules in signaling and binding explains their interaction with various ligands including collagen, DNA, heparin, actins, fibrin, and cytokine receptors on cell surfaces [42, 50]. Several, often contradictory mechanisms have been hypothesized in attempts to explain “encryption-decryption” of TF activity. TFPI contributes significantly to the inhibition of Xa in vivo, despite being present at concentrations of only 2.5 nM. A. Auwerda, Y. Yuana, S. Osanto et al., “Microparticle-associated tissue factor activity and venous thrombosis in multiple myeloma,”, K. Haubold, M. Rink, B. Spath et al., “Tissue factor procoagulant activity of plasma microparticles is increased in patients with early-stage prostate cancer,”, P. L. Gross and N. Vaezzadeh, “Tissue factor microparticles and haemophilia,”, V. Y. Bogdanov, V. Balasubramanian, J. Hathcock, O. Vele, M. Lieb, and Y. Nemerson, “Alternatively spliced human tissue factor: a circulating, soluble, thrombogenic protein,”, P. Censarek, A. Bobbe, M. Grandoch, K. Schrör, and A. Miles, T. S. Edgington, and P. E. Wright, “Recombinant soluble human tissue factor secreted by, F. A. Pitlick, “Concanavalin A inhibits tissue factor coagulant activity,”, J. W. Shands Jr., “Macrophage factor X activator formation: metabolic requirements for synthesis of components,”, R. Bona, E. Lee, and F. Rickles, “Tissue factor apoprotein: intracellular transport and expression in shed membrane vesicles,”, P. Cohen, “The role of protein phosphorylation in neural and hormonal control of cellular activity,”, T. F. Zioncheck, S. Roy, and G. A. Vehar, “The cytoplasmic domain of tissue factor is phosphorylated by a protein kinase C-dependent mechanism,”, R. S. Mody and S. D. Carson, “Tissue factor cytoplasmic domain peptide is multiply phosphorylated in vitro,”, A. Dorfleutner and W. Ruf, “Regulation of tissue factor cytoplasmic domain phosphorylation by palmitoylation,”, B. D. Car, D. O. Slauson, M. Dore, and M. M. Suyemoto, “Endotoxin-mediated bovine alveolar macrophage procoagulant induction is dependent on protein kinase C activation,”, Y. Nishizuka, “Studies and perspectives of protein kinase C,”, H. H. Versteeg, I. Hoedemaeker, S. H. Diks et al., “Factor VIIa/tissue factor-induced signaling via activation of src-like kinases, phosphatidylinositol 3-kinase, and Rac,”, L. K. Poulsen, N. Jacobsen, B. Saulius Butenas, "Tissue Factor Structure and Function", Scientifica, vol. After vessel injury, the TF:FVIIa complex activates the coagulation protease cascade, which leads to fibrin deposition and activation of platelets. Another mechanism for TF activity regulation by S-palmitoylation is based upon its effect on the phosphorylation of the intracellular domain of the protein. The structural biology of expression and function of tissue factor. This neglection was related primarily to the scarce availability of the natural TF protein, and, as a consequence, most of the experiments were done using recombinant TF proteins, despite the known differences in structure and activity of these proteins compared to the natural TF. transient TF expression was not detected upon platelet stimulation for a short (15 min) time [100, 101]. Several groups of investigators reported the presence of TF antigen circulating in blood at the concentrations as high as 5–10 nM [72] and those of active protein reaching (sub)nanomolar concentrations [73]. Other publications, however, show that mercuric chloride oxidizes only a single thiol group [192, 193] and that a similar effect could be achieved by treating TF-bearing cells with other metal compounds [175]. of the C-terminal domain. However, due to the controversy related to the presence of TF on some cell types and platelets, the presence of TF on microparticles shed by those cells remains a subject of the discussion. Some cells release TF in response to blood vessel damage (see next paragraph) and some do only in response to inflammatory mediators (endothelial cells/macrophages). Abstract. The motif is also linked to the immunoglobulin superfamily with the analogous antiparallel Already in 1944, Chargaff et al. Nevertheless, some residues are specific for TF. Another cell type that expresses TF on the cell surface in inflammatory conditions is the monocyte (a white blood cell). Lock, C. Van't Veer, D. P. Gaffney, and K. G. Mann, “Blood clotting in minimally altered whole blood,”, K. M. Cawthern, C. Van't Veer, J. A. Oldstone, D. J. Loskutoff, T. S. Edgington, and N. Mackman, “Astrocytes are the primary source of tissue factor in the murine central nervous system. The main function of the tissue factor pathway is to form a thrombin burst, a … Tissue Factor is the principal cellular initiator of normal blood coagulation. -strands. As a consequence, there is plenty of controversy in published studies related to the structure/activity of natural TF. Cytokines are small proteins that can influence the behavior of white blood cells. Tissue factor (TF) is an integral membrane protein that is essential to life. Additionally, it leads to a scarcity of data addressing the influence of some structural components of natural TF on its activity. Tissue factor-induced blood coagulation was studied in 20 individuals, for varying periods of time during 54 months, in contact pathway-inhibited whole blood at 37 degrees C and evaluated in terms of the activation of various substrates. and A. Bouchard, K. G. Mann, and S. Butenas, “No evidence for tissue factor on platelets,”, B. Osterud and E. Bjorklid, “Sources of tissue factor,”, B. Osterud and E. Bjorklid, “Tissue factor in blood cells and endothelial cells,”, M. Camera, M. Brambilla, V. Toschi, and E. Tremoli, “Tissue factor expression on platelets is a dynamic event,”, B. In contrast to Camera et al. Tissue factor (TF) is the main initiator of coagulation in both physiologic and pathologic conditions, functioning as the receptor and allosteric cofactor for plasma protease factor VIIa (FVIIa). Each module is composed of two overlapping beta sheets with the top sheet containing three antiparallel beta strands and the bottom sheet containing four beta strands [42, 49–52]. Copyright © 2012 Saulius Butenas. At all three glycosylation sites, recombinant TF 1–263 predominantly contains high mannose sugars, whereas natural placental protein contains either hybrid or complex carbohydrates with high mannose sugars absent. The ultimate aim is for these clotting factors to eventually convert the necessary components that will form a blood clot. Objective: The aim of the present study is to investigate the importance of TF glycosylation in transport to the cell surface and its coagulant and signaling functions. Many cells, both healthy, and tumor cells, produce detectable amounts of TF, especially when they are stimulated by vari… It is a component of the factor VIIa-TF complex enzyme and plays a primary role in both normal hemostasis and thrombosis. The strands are connected by β-loops between strand The F3 gene locates on chromosome 1p22-p21 and contains 6 exons that produce a precursor protein with 294 amino acids. This test is called the aPTT, or activated partial thromboplastin time. TF classical role in initiating the extrinsic blood coagulation and its direct thrombotic action in close relation to cardiovascular risks have long been established. It is frequently encrypted in the plasma membrane of cells in contact with blood, but under certain pathological conditions endothelial cells, monocytes or macrophages may express tissue factor; and hence trigger coagulation activation. Generation and Application of Active Recombinant Mouse Tissue Factor and Its Function-blocking Monoclonal Antibody*. A. Bouchard, K. E. Brummel-Ziedins, B. Parhami-Seren, and K. G. Mann, “Tissue factor activity in whole blood,”, J. Krudysz-Amblo, M. E. Jennings, K. G. Mann, and S. Butenas, “Carbohydrates and activity of natural and recombinant tissue factor,”, W. H. Seegers, “Activation of purified prothrombin,”, K. G. Mann, M. E. Nesheim, K. R. Church, P. Haley, and S. Krishnaswamy, “Surface-dependent reactions of the vitamin K-dependent enzyme complexes,”, Y. Komiyama, A. H. Pedersen, and W. Kisiel, “Proteolytic activation of human factors IX and X by recombinant human factor VIIa: effects of calcium, phospholipids, and tissue factor,”, V. J. J. Bom and R. M. Bertina, “The contributions of Ca, K. G. Mann, S. Krishnaswamy, and J. H. Lawson, “Surface-dependent hemostasis,”, M. E. Nesheim, J. Binding of VIIa to TF has also been found to start signaling processes inside the cell. The signaling function of TF/VIIa plays a role in angiogenesis and apoptosis. After deglycosylation, the catalytic efficiency of factor Xa generation became comparable for the placental, recombinant 1–263 and native recombinant TF 1–243 (Figure 6). It possesses an antithrombotic action and also the ability to associate with lipoproteins in plasma. Using validated assays for the quantitation of TF antigen [135] and activity [138] developed in our laboratory, we found that the TF antigen concentrations in plasmas from patients with a similar diagnosis are at low picomolar levels, with an average functional concentration less than 0.4 pM [138]. Increasing experimental data suggest a role for these rafts in modification of tissue factor expression [165, 166] and activity [167–170], although the latter subject remains controversial [171]. Emerging evidence shows a broad spectrum of biological functions of tissue factor (TF). Based on a similar activity of carbohydrate-free recombinant TF from E. coli and glycosylated protein expressed by kidney cells, it was concluded that carbohydrates play no role in TF function. B. Hansen, “Evidence for direct transfer of tissue factor from monocytes to platelets in whole blood,”, M. Hayashi, K. Takeshita, Y. Inden et al., “Platelet activation and induction of tissue factor in acute and chronic atrial fibrillation: involvement of mononuclear cell-platelet interaction,”, A. Zillmann, T. Luther, I. Müller et al., “Platelet-associated tissue factor contributes to the collagen-triggered activation of blood coagulation,”, I. Müller, A. Klocke, M. Alex et al., “Intravascular tissue factor initiates coagulation via circulating microvesicles and platelets,”, O. Panes, V. Matus, C. G. Sáez, T. Quiroga, J. Pereira, and D. Mezzano, “Human platelets synthesize and express functional tissue factor,”, H. Schwertz, N. D. Tolley, J. M. Foulks et al., “Signal-dependent splicing of tissue factor pre-mRNA modulates the thrombogenecity of human platelets,”, M. Camera, M. Frigerio, V. Toschi et al., “Platelet activation induces cell-surface immunoreactive tissue factor expression, which is modulated differently by antiplatelet drugs,”, M. Camera, M. Brambilla, L. Facchinetti et al., “Tissue factor and atherosclerosis: not only vessel wall-derived TF, but also platelet-associated TF,”, M. Brambilla, M. Camera, D. Colnago et al., “Tissue factor in patients with acute coronary syndromes: expression in platelets, leukocytes, and platelet-leukocyte aggregates,”, B.