This Program Project, under the direction of Robert W. Coleman, Molecular Basis for Platelet Function in Hemostasis, will exist within the Sol Sherry Thrombosis Research Center of Temple University School of Medicine. The Center is a formally established research institute within the School of Medicine dedicated to advancing our understanding of the etiology/pathogenesis, diagnosis and treatment of arterial and venous thrombosis and hemorrhagic diseases. To fulfill this goal, investigators in this project will examine the mechanisms of activation of platelets in hemostasis and thrombogenesis. Each project in the present proposal has the potential to indicate or provide the foundation for development of an appropriate inhibitory drug or therapeutic approach to prevent platelet activation, aggregation, and coagulant activity. and second messengers in particular, cyclic nucleotides and platelet coagulant activities. Project 1, Active Site Amino Acids of cAMP Phosphodiesterase 3A (R.W. Colman), concentrates on the delineation on the critical amino acids in active sites of the major cAMP phosphodiesterase in platelet. The amino acids critical for catalysis and metal binding of type 3A PDE will be identified by affinity labeling and site-directed mutagenesis. Project 2, Platelet Factor XI (P.N. Walsh), will structurally characterize platelet factor XI and study the mechanism of agonist exposure of actor XI in platelets. The mode of activation, cellular localization, and functional characteristics of platelet factor XI will be investigated. Project 3, Signal Transduction Defects in Human Platelets (A.K. Rao), will seek new insights into platelet signal transduction mechanisms by the biochemical and molecular biological dissection of the defects of a selected group of patients with qualitative defects focusing on abnormalities in PLC-b1a and Gaq. Project 4, Platelet ADP Receptors (S.P. Kunapuli), will elucidate the role of 3 ADP receptor subtypes in platelet fibrinogen receptor activation. Core A, Administration (R.W. Colman), will provide fiscal oversight and clerical support for all projects. Core B, Cell Culture (S.P. Kunapuli), will facilitate and support all of the projects and thus efficiently expedite the research. Core C, Flow Cytometry (J.K. deRiel), will provide fluorescent-activated cell analysis and confocal services to all projects. All of these investigators have a history of collaborative research with more than one of the other project leaders and will consult and share intellectual and physical resources with the other project leaders. The knowledge gained from these studies will provide therapeutic approaches to enhancing hemostasis and preventing thrombosis.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Program Projects (P01)
Project #
5P01HL064943-04
Application #
6638661
Study Section
Heart, Lung, and Blood Initial Review Group (HLBP)
Program Officer
Hasan, Ahmed AK
Project Start
2000-05-01
Project End
2005-04-30
Budget Start
2003-05-01
Budget End
2004-04-30
Support Year
4
Fiscal Year
2003
Total Cost
$1,323,696
Indirect Cost
Name
Temple University
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
057123192
City
Philadelphia
State
PA
Country
United States
Zip Code
19122
Hung, Su H; Liu, Andy H; Pixley, Robin A et al. (2008) A new nonhydrolyzable reactive cGMP analogue, (Rp)-guanosine-3',5'-cyclic-S-(4-bromo-2,3-dioxobutyl)monophosphorothioate, which targets the cGMP binding site of human platelet PDE3A. Bioorg Chem 36:141-7
Murugappa, Swaminathan; Kunapuli, Satya P (2006) The role of ADP receptors in platelet function. Front Biosci 11:1977-86
Hung, Su-Hwi; Zhang, Wei; Pixley, Robin A et al. (2006) New insights from the structure-function analysis of the catalytic region of human platelet phosphodiesterase 3A: a role for the unique 44-amino acid insert. J Biol Chem 281:29236-44
Quinton, T M; Kim, S; Jin, J et al. (2005) Lipid rafts are required in Galpha(i) signaling downstream of the P2Y12 receptor during ADP-mediated platelet activation. J Thromb Haemost 3:1036-41
Wakabayashi, Hironao; Su, Ya-Chi; Ahmad, Syed S et al. (2005) A Glu113Ala mutation within a factor VIII Ca2+-binding site enhances cofactor interactions in factor Xase. Biochemistry 44:10298-304
Ahmad, Syed S; Walsh, Peter N (2005) Role of the C2 domain of factor VIIIa in the assembly of factor-X activating complex on the platelet membrane. Biochemistry 44:13858-65
Navaneetham, Duraiswamy; Jin, Lei; Pandey, Pramod et al. (2005) Structural and mutational analyses of the molecular interactions between the catalytic domain of factor XIa and the Kunitz protease inhibitor domain of protease nexin 2. J Biol Chem 280:36165-75
Ding, Zhongren; Tuluc, Florin; Bandivadekar, Kavita R et al. (2005) Arg333 and Arg334 in the COOH terminus of the human P2Y1 receptor are crucial for Gq coupling. Am J Physiol Cell Physiol 288:C559-67
Yang, Xia; Walsh, Peter N (2005) An ordered sequential mechanism for Factor IX and Factor IXa binding to platelet receptors in the assembly of the Factor X-activating complex. Biochem J 390:157-67
Sinha, Dipali; Marcinkiewicz, Mariola; Lear, James D et al. (2005) Factor XIa dimer in the activation of factor IX. Biochemistry 44:10416-22

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