A proteomic analysis of changes in prothrombin and plasma proteins associated with the G20210A mutation

The G-->A mutation at position 20210 of the prothrombin gene, localized in the 3'-polyadenylation untranslated region of the mRNA, is a recognized genetic risk factor for venous thromboembolism. The mechanism by which this base change confers an increased risk of thrombosis compared to noncarriers is undefined. Studies on the mRNA suggest enhanced cleavage site recognition and a change in the location of the 3'-cleavage/polyadenylation reaction, but no defined model has been proposed. The present study, based on proteomic investigation by two-dimensional gel electrophoresis and electrospray ionization (ESI) tandem mass spectrometry (MS/MS) protein identification, suggests that the G20210A mutation is associated with increased glycosylation of prothrombin, which confers greater stability to the protein. Additionally, proteomic investigation of pooled plasma showed that expression levels of six spots, three of them identified by ESI MS/MS, were altered in subjects carrying the mutation, suggesting a possible cooperative effect in the thrombotic risk increment induced by the mutation.