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This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Rights and Permissions Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Hu, C.-j. Articles by Walsh, P. N. Search for Related Content PubMed PubMed Citation Articles by Hu, C.-j. Articles by Walsh, P. N. Related Collections Hemostasis, Thrombosis, and Vascular Biology Social Bookmarking                   What's this?  Previous Article  |  Table of Contents  |  Next Article  Tissue-Specific Expression of Functional Platelet Factor XI Is Independent of Plasma Factor XI Expression Chang-jun Hu, Frank A. Baglia, David C.B. Mills, Barbara A. Konkle, and Peter N. Walsh From the Departments of Biochemistry and Medicine, The Sol Sherry Thrombosis Research Center, Temple University School of Medicine, Philadelphia, PA; and the Cardeza Foundation, Thomas Jefferson University, Philadelphia, PA. Platelet factor XI is an alternatively spliced product of the factor XI gene expressed specifically within megakaryocytes and platelets as an approximately 1.9-kb mRNA transcript (compared with ~2.1 kb in liver cells) lacking exon V. Flow cytometry with an affinity-purified factor XI antibody, with PAC1 antibody (to the GPIIb/IIIa complex on activated platelets), and with S12 antibody (to P-selectin, an -granule membrane protein expressed on the platelet surface during secretion) on platelets activated with ADP, thrombin, thrombin receptor peptide (SFLLRN amide), or collagen at various concentrations exposed platelet factor XI and PAC1 antibody binding in parallel. Unactivated platelets expressed approximately 40% of total platelet factor XI but no PAC1 binding sites. Enhanced membrane exposure of platelet factor XI is independent of -granule secretion, because ADP and collagen exposed platelet factor XI but no S12 binding sites. Platelets from four patients with plasma factor XI deficiency (<0.04 U/mL) had normal constitutive and activation-dependent expression of platelet factor XI. Well-washed platelets from normal and from factor XI-deficient donors incubated with low concentrations of thrombin (0.05 to 0.1 U/mL) corrected the clotting defect observed with factor XI-deficient plasma. Thus, functionally active platelet factor XI is differentially expressed on platelet membranes in a tissue-specific manner both constitutively and in a concentration-dependent fashion by various agonists in the absence of detectable plasma factor XI. Blood, Vol. 91 No. 10 (May 15), 1998: pp. 3800-3807 © 1998 by The American Society of Hematology. CiteULike    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this? This article has been cited by other articles: K. G. Mann, S. Butenas, and K. Brummel The Dynamics of Thrombin Formation Arterioscler Thromb Vasc Biol, January 1, 2003; 23(1): 17 - 25. [Abstract] [Full Text] [PDF] T. Renne, D. Gailani, J. C. M. Meijers, and W. Muller-Esterl Characterization of the H-kininogen-binding Site on Factor XI. A COMPARISON OF FACTOR XI AND PLASMA PREKALLIKREIN J. Biol. Chem., February 8, 2002; 277(7): 4892 - 4899. [Abstract] [Full Text] [PDF] D. Martincic, V. Kravtsov, and D. Gailani Factor XI Messenger RNA in Human Platelets Blood, November 15, 1999; 94(10): 3397 - 3404. [Abstract] [Full Text] [PDF] J. A. Oliver, D. M. Monroe, H. R. Roberts, and M. Hoffman Thrombin Activates Factor XI on Activated Platelets in the Absence of Factor XII Arterioscler Thromb Vasc Biol, January 1, 1999; 19(1): 170 - 177. [Abstract] [Full Text] [PDF]

	Copyright © 1998 by American Society of Hematology         Online ISSN: 1528-0020