Protein S is a key component for the regulation of hemostasis. Protein S serves as a cofactor for activated protein C, an enzyme responsible for the degradation of two protein elements of the blood coagulation pathway. Consequently, protein S through the action of protein C down-regulates the blood clotting process. Individuals deficient in functional protein S, either because of genetic or environmentally-acquired reasons, are at a higher risk of experiencing thrombotic disorders. Symptoms commonly associated with Protein S deficiency include thrombophlebitis, deep vein thrombosis, and pulmonary emboli. At the present time the genetic basis of protein S deficiency and its relationship to thrombosis are unknown. The long-term objective of the proposed research is to understand the genetic basis of protein S deficiency and thrombosis. This will be accomplished, in part, through the proposed studies, designed to provide a better understanding of the normal and abnormal protein S genes and the functional properties of the protein S products. Specific methods for achieving these goals include: a) cloning and characterization (by restriction endonuclease and DNA sequencing) of the normal human protein S gene and comparison to that from genetically protein S deficient individuals, b) chromosomal localization of the protein S gene by specific hybridization of protein S cDNA to mouse-human cell hybrids lacking different human chromosomes, c) quantitation of protein S messenger RNA levels in cells believed or suspected of participating in hemostasis and under the influence of hemostatic regulatory factors, and d) site-directed mutagenesis of protein S to address structure/function relationships, including the role of beta-hydroxyaspartic and gamma-carboxyglutamic acids, thrombin cleavage, and epidermal growth factor, propeptide and """"""""Gla"""""""" domains in proteins S. The results may eventually lead to improved methods of diagnosis and therapy for patients having protein S deficiency and/or suffering from thrombotic disorders.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
1R01HL038899-01
Application #
3355352
Study Section
Biochemistry Study Section (BIO)
Project Start
1987-07-01
Project End
1992-06-30
Budget Start
1987-07-01
Budget End
1988-06-30
Support Year
1
Fiscal Year
1987
Total Cost
Indirect Cost
Name
University of Vermont & St Agric College
Department
Type
Schools of Medicine
DUNS #
066811191
City
Burlington
State
VT
Country
United States
Zip Code
05405
Lu, D; Xie, R L; Rydzewski, A et al. (1997) The effect of N-linked glycosylation on molecular weight, thrombin cleavage, and functional activity of human protein S. Thromb Haemost 77:1156-63
Li, M; Long, G L (1996) Identification of two novel point mutations in the human protein S gene associated with familial protein S deficiency and thrombosis. Arterioscler Thromb Vasc Biol 16:1407-15
Rydzewski, A; Myyyliwiec, M; Long, G L (1996) Construction, expression and preliminary characterization of glycosylation mutants of human protein S. Pol J Pharmacol 48:197-201
Lu, D; Schmidel, D K; Long, G L (1994) Structure of mouse protein S as determined by PCR amplification and DNA sequencing of cDNA. Thromb Res 74:135-42
Long, G L; Tomczak, J A; Rainville, I R et al. (1994) Homozygous type I protein C deficiency in two unrelated families exhibiting thrombophilia related to Ala136-->Pro or Arg286-->His mutations. Thromb Haemost 72:526-33
Nelson, R M; Long, G L (1992) Binding of protein S to C4b-binding protein. Mutagenesis of protein S. J Biol Chem 267:8140-5
Nelson, R M; Long, G L (1991) Solution-phase equilibrium binding interaction of human protein S with C4b-binding protein. Biochemistry 30:2384-90
Messier, T L; Pittman, D D; Long, G L et al. (1991) Cloning and expression in COS-1 cells of a full-length cDNA encoding human coagulation factor X. Gene 99:291-4
Villarreal, X C; Malaval, L; Mann, K G et al. (1991) Epitope mapping of two monoclonal antibodies to the central portion of human osteonectin. Calcif Tissue Int 48:138-41
Schmidel, D K; Nelson, R M; Broxson Jr, E H et al. (1991) A 5.3-kb deletion including exon XIII of the protein S alpha gene occurs in two protein S-deficient families. Blood 77:551-9

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