TFPI
TFPI (tissue factor pathway inhibitor, also known as EPI, TFI, TFPI1 and LACI) is a Kunitz-type serine protease inhibitor that regulates the tissue factor-dependent pathway of blood coagulation. It inhibits factor Xa directly and restrains factor VIIa/tissue factor activity. Browse Assay Genie's current range of TFPI research reagents below, or read on for the biology behind the target.
TFPI acts as a brake on the extrinsic pathway of blood coagulation. Coagulation begins when factor VIIa forms a complex with tissue factor (TF), which proteolytically activates further proteases, including factors IX and X, and ultimately leads to the formation of a fibrin clot. TFPI inhibits activated factor X (Xa) directly and, in a Xa-dependent manner, inhibits VIIa/TF activity, presumably by forming a quaternary Xa/LACI/VIIa/TF complex. Together these actions create an autoregulatory loop and give the protein its antithrombotic action.
The TFPI gene encodes a Kunitz-type serine protease inhibitor. UniProt records the protein as secreted and also associated with microsome membranes, and notes that it can associate with lipoproteins in plasma. This lipoprotein association explains the older name, lipoprotein-associated coagulation inhibitor (LACI), which survives as an alias alongside EPI, TFI and TFPI1. The gene encodes multiple protein isoforms that differ in their inhibitory activity, specificity and cellular localisation, so the choice of isoform matters when interpreting experimental results.
TFPI is of particular interest in haemostasis research. Inhibition of the encoded protein restores haemostasis in animal models of haemophilia, which has made it a focus for work on how the TF pathway is controlled. Mouse and rat both carry a Tfpi ortholog, allowing comparative and in vivo studies of the pathway. A related gene, TFPI2, encodes a second member of the tissue factor pathway inhibitor naming group and is often considered alongside TFPI.
TFPI regulates the factor VIIa-TF pathway and inhibits factor Xa, making it central to studies of how clot formation is initiated and limited.
Inhibition of TFPI restores haemostasis in animal models of haemophilia, so the protein is studied in work on bleeding disorders.
TFPI has an antithrombotic action through its Xa-dependent inhibition of VIIa/TF, relevant to research on thrombosis and anticoagulant control.
TFPI can associate with lipoproteins in plasma, which links coagulation control with lipoprotein-related studies of the protein's distribution and function.
TFPI is a Kunitz-type serine protease inhibitor that regulates the tissue factor-dependent coagulation pathway. It inhibits factor Xa directly and, in a Xa-dependent way, inhibits factor VIIa/tissue factor activity, giving it an antithrombotic action.
TFPI is also known as EPI, TFI, TFPI1 and LACI (lipoprotein-associated coagulation inhibitor). The gene encodes multiple protein isoforms that differ in their inhibitory activity, specificity and cellular localisation, so check the datasheet of any product for its validated reactivity and isoform coverage.
Mouse and rat both have an orthologous Tfpi gene. TFPI is studied in haemostasis because inhibiting the protein restores haemostasis in animal models of haemophilia. Check the datasheet of any product for its validated reactivity.
TFPI2 and other coagulation-pathway targets with products at Assay Genie.
Gene and protein annotations from HGNC, NCBI Gene and UniProt P10646; product specifications from Assay Genie datasheets.