Characterization of the complementary deoxyribonucleic acid and gene coding for human prothrombin

Abstract

The DNA sequences of a complementary deoxyribonucleic acid (cDNA) and a portion of the gene coding for human prothrombin have been determined. The cDNA was 2005 base pairs in length and was found to code for part of a leader sequence of 36 amino acids, 579 amino acids present in the mature protein, a stop codon, a noncoding region of 97 base pairs, and a poly(A) tail of 27 base pairs. It is proposed that the leader sequence consists of a signal sequence and a pro sequence for the mature protein that circulates in plasma. The 10 glutamic acid residues that are present in the amino-terminal region of prothrombin and are converted to gamma-carboxyglutamic acid in the mature protein are coded by only the GAG codon. The cDNA for prothrombin was also employed as a probe for screening a human fetal liver genomic DNA library. One of the strongly positive phage containing a human DNA insert of 5 kilobases was mapped with restriction endonucleases and sequenced. This DNA contained approximately half of the gene for human prothrombin and included six introns and five exons coding for amino acid residues 144-448. The two largest intervening sequences in the genomic DNA contained two copies each of AluI repetitive DNA.

Limulus factor D, a 43‐kDa protein isolated from horseshoe crab hemocytes, is a serine protease homologue with antimicrobial activity

“…3A). This pseudo-serine protease domain of factor D was more closely related to the catalytic domains of human tissue plasminogen activator [22] (31.7% identity) and also human plasmin [23] (29.4%) than to those of human Cls [24] (27.9%) and human thrombin [25] (23.3%). Among four serine proteases involved in the horseshoe crab coagulation cascade, the sequence of factor D showed the highest similarity with that of the clotting enzyme [26] (31.7%).…”

The G20210A mutation does not affect the stability of prothrombin mRNA in vivo

“…2 This mutation is a G3A transversion at position 20210, the accepted prothrombin messenger RNA (mRNA) polyadenylation site. 3 Heterozygotes for the 20210A gene variant express prothrombin at levels that are about 25% higher than average. 1,4,5 The physiological importance of the 20210A mutation is evidenced by the significant risk of venous 1,6 and arterial thromboembolism 5,7,8 displayed by 20210G/A heterozygotes, which can be particularly severe in specific subpopulations and target organs.…”

Gene Therapy for Coagulation Disorders

“…[8][9][10][11] These discoveries confirmed that the coagulation proteins were derived from genes which encoded modular domains that were shared between related families of coagulation factors (eg, the vitamin K-dependent factors and factors V and VIII). Soon after the cloning of the FVIII and FIX genes, translational application of this knowledge was initiated through the introduction of molecular diagnostics, 12 the development of recombinant clotting factors for replacement therapy, 13 and the initial preclinical trials of gene therapy.…”