SNP Map of the Protein C Gene
A. Pavlova, C. Geisen, M. Lim-Eimer, M. Watzka, E. Seifried and J. Oldenburg
Introduction
Protein C is a vitamin K dependent anticoagulant protein that plays an important role in the regulation of the hemostatic system. Activated protein C exerts its antico- agulant effect by inactivating factor Va and VIIIa and thereby reducing thrombin generation. Deficiency of protein C is associated with an increased risk for venous thrombosis. The human protein C gene maps to chromosome 2q13-14 and compri- ses a coding region (exons 2 to 9) and a 5’ untranslated region encompassing exon 1 (Fig. 1a) [2, 4]. Protein C is a member of the vitamin K-dependent family and con- tains a phospholipid-binding Gla domain, 2 epidermal growth factor (EGF) domains (the light chain) and a serine protease (SP) domain (the heavy chain) (Fig. 1b) [1, 5].
The aim of the present study was to investigate the genetic variability of the protein C gene in the normal population.
Signal Pro GLA EGF Serinprotease peptide
- 42 -25 -24 -1 1 38 46 91 92 136 170 419 Promoto Exon 2 Exon 3
Exon 4 Exon 5
Exon 6 Exon 7 Exon 8 Exon 9
a)
b)
Fig. 1a, b. Structure of human Protein C gene and protein. a) Humen Protein C gene 쏋 -Exons
쏋-Intros 쏋-Promotor. b) Human Protein C protein 쏋-presentation of the domain struc-ture of the protein
I. Scharrer/W. Schramm (Ed.)
34
thHemophilia Symposium Hamburg 2003
” Springer Medizin Verlag Heidelberg 2005
Materials and Methods
200 healthy blood donors (100 males and 100 females), representing 400 alleles, were screened for the presence of polymorphisms in the Protein C gene. Denaturing High Performance Liquid Chromatography (DHPLC) was applied as a screening strategy followed by direct sequencing of the fragments with abnormal patterns.
Results and Discussion
In total, 12 different polymorphisms were identified in examination of 400 alleles – 2 in Promotor (untranslated region) , 5 in the intronic parts of the gene and 5 in the protein coding exons 2 to 9 (translated region). Eight of them, with relatively rare frequency were described for the first time – #2,3,4,5,6,10,11,12 (Table 1). From the other four polymorphisms, three (655A>T, 5472 T>G, 9385 T>C) were common with a frequency of 0.42, 0.37 and 0.28, respectively [3]. Two of them were in the exon 6 (5472 T>G) and 8 (9385 T>C) and 1 was in Promotor (655A>T). Only one rare polymorphism (10830 A>G) in exon 9 exhibited an amino acid substitution (N329D).
Conclusion
In conclusion, only a single polymorphic allele with an amino acid exchange could be found in Protein C in 400 alleles, suggesting that this protein is highly conserved in the normal population. Thus no polymorphic candidates for the modulation of protein C activity could be identified so far.
356 A. Pavlova et al.
Exon 2 Promotor
Exon 3 Exon 4 Exon 5 Exon 6 Exon 7 Exon 8 Exon 9
Fig 2. Schematic presentation of the polymorphisms in human Protein C.
쏋-Exons 쏋-Introns 쏋Promotor 쏋-Polymorphisms
