Tissue factor pathway inhibitor

Tissue factor pathway inhibitor (lipoprotein-associated coagulation inhibitor)
250px PDB rendering based on 1adz.
Available structures PDB Ortholog search: PDBe, RCSB List of PDB id codes 1ADZ, 1IRH, 1TFX, 4BQD, 4DTG
Identifiers
Symbols	TFPI ; EPI; LACI; TFI; TFPI1
External IDs	OMIM: 152310 MGI: 1095418 HomoloGene: 4579 GeneCards: TFPI Gene
Gene ontology Molecular function • endopeptidase inhibitor activity • serine-type endopeptidase inhibitor activity Cellular component • extracellular region • extracellular space • endoplasmic reticulum • plasma membrane • cell surface • organelle membrane • anchored component of membrane Biological process • blood coagulation • blood coagulation, extrinsic pathway • negative regulation of endopeptidase activity Sources: Amigo / QuickGO
RNA expression pattern
File:PBB GE TFPI 209676 at tn.png
File:PBB GE TFPI 210664 s at tn.png
File:PBB GE TFPI 210665 at tn.png
More reference expression data
Orthologs
Species	Human	Mouse
Entrez	7035	21788
Ensembl	ENSG00000003436	ENSMUSG00000027082
UniProt	P10646	O54819
RefSeq (mRNA)	NM_001032281	NM_001177319
RefSeq (protein)	NP_001027452	NP_001170790
Location (UCSC)	Chr 2: 187.46 – 187.57 Mb	Chr 2: 84.43 – 84.48 Mb
PubMed search	[1]	[2]

Tissue factor pathway inhibitor (or TFPI) is a single-chain polypeptide which can reversibly inhibit Factor Xa (Xa). While Xa is inhibited, the Xa-TFPI complex can subsequently also inhibit the FVIIa-tissue factor complex. TFPI contributes significantly to the inhibition of Xa in vivo, despite being present at concentrations of only 2.5 nM.

Genetics

The gene for TFPI is located on chromosome 2q31-q32.1, and has nine exons which span 70 kb. The gene has not been completely sequenced yet. A similar gene, termed TFPI2, has been identified on chromosome 7q22; in addition to TFPI activity, its product also has retinal pigment epithelial cell growth-promoting properties.

Protein structure

TFPI has a relative molecular mass of 34,000 to 40,000 depending on the degree of proteolysis of the C-terminal region.

TFPI consists of a highly negatively charged amino-terminus, three tandemly linked Kunitz domains, and a highly positively charged carboxy-terminus. With its Kunitz domains, TFPI exhibits significant homology with human inter-alpha-trypsin inhibitor and bovine basic pancreatic trypsin inhibitor.

Interactions

Tissue factor pathway inhibitor has been shown to interact with Factor X.

See also

• Hemostasis

External links

• Online 'Mendelian Inheritance in Man' (OMIM) 152310 (TFPI1), Online 'Mendelian Inheritance in Man' (OMIM) 600033 (TFPI2)