Platelet Factor XIII Becomes Active without the Release of Activation Peptide during Platelet Activation

Summary

The potentially active A subunit of factor XIII of blood coagulation has also been detected in platelets and monocytes/macrophages though the exact function of this cellular protransglutaminase has not yet been elucidated. In physiological conditions the first step in the activation of plasma factor XIII is the removal of an activation peptide from the N-terminal end of subunit A by thrombin. The A subunit then, in the presence of Ca²⁺, dissociates from the inhibitory B subunit and assumes an active conformation. Cellular factor XIII, which lacks B subunit, can be proteolytically activated in vitro by thrombin and the intracellular Ca²⁺ sensitive protease, calpain, in the same way as plasma factor XIII subunit A, and calpain has been suggested as the intracellular protease involved in the activation of cellular factor XIII in platelets. In the present experiments it was shown by SDS PAGE that during long-term stimulation of platelets with thrombin nondisulfide-crosslinked high M _r protein polymers not penetrating the concentrating gel were formed. The lack of these polymers in thrombin-stimulated factor XIII deficient platelets clearly indicated that their formation in normal platelets was due to factor XIII that became active during platelet activation. However, no release of the activation peptide could be detected by Western blotting during this process. Similarly, no proteolytic cleavage of factor XIII was detectable when platelets were stimulated by Ca²⁺ ionophore through this stimulus activated calpain as it was clearly demonstrated by the breakdown of major intracellular calpain substrates. The results indicate: 1) during thrombin induced platelet activation factor XIII becomes active and crosslinks platelet protein, 2) platelet factor XIII is not an intracellular substrate of calpain, 3) cellular factor XIII could be activated without the proteolytic removal of activation peptide. It is presumed that the nonproteolytic pathway for the activation of cellular factor XIII, we reported most recently, might have physiological implications under such conditions.

• References

• 1 Muszbek L, Laki K. Interaction of thrombin with proteins other than fibrinogen (thrombin susceptible bonds). Activation of factor XIII. In: Thrombin. Machovich R. (ed). CRC Press; Boca Raton, CA: 1984: 83-102
• 2 McDonagh J. Structure and function of factor XIII. In: Hemostasis and Thrombosis. 2.. Colman RW, Hirsh J, Marder WJ, Salzman EW. (eds). Lippincott; Philadelphia, PA: 1987: 289-300
• 3 Buluk K. An unknown function of blood platelets. Pol Tyg Lek 1955; 10: 191
• 4 Lüscher EF. Ein fibrinstabilisierender Faktor aus Thrombozyten. Schweiz Med Wochensch 1957; 87: 1220-1221
• 5 Muszbek L, Ádány R, Szegedi G, Polgár J, Kavai M. FXIII of blood coagulation in human monocytes. Thromb Res 1985; 37: 401-410
• 6 Ádány R, Belkin A, Vasilevskaya T, Muszbek L. Identification of blood coagulation factor XIII in human peritoneal macrophages. Eur J Cell Biol 1985; 38: 171-173
• 7 Henriksson P, Becker S, Lynch G, McDonagh J. Identification of intracellular factor XIII in human monocytes and macrophages. J Clin Invest 1985; 76: 528-534
• 8 Áány R, Glukhova MA, Kabakov AY, Muszbek L. Characterization of human connective tissue cells containing factor XIII subunit a. J Clin Pathol 1987; 41: 49-56
• 9 Cohen I, Glaser T, Veis A, Brunner-Lorand J. Ca²⁺ dependent crosslinking processes in human platelets. Biochim Biophys Acta 1981; 676: 137-147
• 10 Cohen I, Lim CT, Kahn DR, Glaser T, Gerrard JM, White JG. Disulfide-linked and transglutaminase-catalyzed protein assemblies in platelets. Blood 1985; 66: 143-151
• 11 Ando Y, Imamura S, Yamagata Y, Kitahara A, Saji H, Murachi T, Kannagi R. Platelet factor XIII is activated by calpain. Biochem Biophys Res Commun 1987; 144: 484-490
• 12 Massini P, Käser-Glanzmann R, Lüscher EF. Movement of calcium ions and their role in the activation of platelets. Thromb Haemostas 1978; 40: 212-218
• 13 Gerard JM. Calcium translocations. In: Platelet Responses and Metabolism. Vol III Holmsen H. (ed). CRC Press; Boca Raton, CA: 1986: 5-29
• 14 Hawiger J, Steer ML, Salzman EW. Intracellular regulatory processes in platelets. In: Hemostasis and Thrombosis. 2. Colman RW, Hirsh J, Marder VJ, Salzman EW. (eds). Lippincott; Philadelphia: 1987: 710-725
• 15 Bohn H, Schwick HG. Isolierung und Charakterisierung eines fibrin-stabilisierenden Faktors aus menschlichen Plazenten. Arzneim Forsch 1971; 21: 1432-1439
• 16 Polgár J, Hidasi V, Muszbek L. Non-proteolytic activation of cellular protransglutaminase (placental macrophage factor XIII). Biochem J 1990; 267: 557-560
• 17 McDonagh J, Waggoner WG, Hamilton EG, Hindenach B, McDonagh RP. Affinity chromatography of human plasma and platelet factor XIII on organomercurial agarose. Biochim Biophys Acta 1976; 446: 345-357
• 18 Muszbek L, Laposata M. Covalent modification of platelet proteins by palmitate. Blood 1989; 74: 1339-1347
• 19 Boda Z, Pfliegler G, Muszbek L, Tóth A, Ádány R, Hársfalvi J, Papp Z, Tornai I, Rák K. Congenital factor XIII deficiency with multiple benign breast tumours and successful pregnancy with substitutive therapy. Haemostasis 1989; 19: 348-352
• 20 Laemmli UK. Cleavage of structural proteins during the assembly of the head of bacteriophage T₄ . Nature 1970; 227: 680-682
• 21 Hársfalvi J, Fésüs L, Tarcsa E, Laczkó J, Loewy AG. The presence of a covalently cross-linked matrix in human platelets. Biochim Biophys Acta 1991; 1073: 268-274
• 22 Muszbek L, Ádány R, Kávai M, Boda Z, Lopaciuk S. Monocytes of patients congenitally deficient in plasma factor XIII lack factor XIII subunit A antigen and transglutaminase activity. Thromb Haemostas 1988; 59: 231-235
• 23 Philips DR, Jakabova M. Ca²⁺-dependent protease in human platelets. Specific cleavage of platelet polypeptides in the presence of added Ca²⁺ . J Biol Chem 1977; 252: 5602-5605
• 24 White GC. Calcium dependent proteins in platelets. Response of calcium-activated protease in normal and thrombasthenic platelets to aggregating agents. Biochim Biophys Acta 1980; 631: 130-138
• 25 Fox JEB, Reynolds CC, Philips DR. Calcium-dependent proteolysis occurs during platelet aggregation. J Biol Chem 1983; 258: 9973-9981
• 26 Credo RB, Curtis CG, Lorand L. Ca²⁺-related regulatory function of fibrinogen. Proc Natl Acad Sci USA 1978; 75: 4234-4237
• 27 Lorand L. Activation of blood coagulation factor XIII. Ann NY Acad Sci 1986; 485: 144-158