Tissue Factor Pathway Inhibitor 2 (TFPI2)

TFPI is an important regulator of the extrinsic pathway of blood coagulation through its ability to inhibit factor Xa and factor VIIa-tissue factor activity. Sprecher et al. described the molecular cloning and expression of a full-length cDNA that encodes a molecule, designated TFPI2, that has a similar overall domain organization and considerable primary amino acid sequence homology to TFPI. After a 22-residue signal peptide, the mature TFPI2 protein contains 213 amino acids with 18 cysteines and 2 canonical N-linked glycosylation sites. The deduced sequence of mature TFPI2 revealed a short acidic N-terminal region, 3 tandem Kunitz-type domains, and a C-terminal tail highly enriched in basic amino acids. Northern analysis demonstrated that the TFPI2 gene is transcribed in umbilical vein endothelial cells, liver, and placenta.