Fibroblast Activation Protein
Fibroblast Activation Protein (FAP) is a cell surface glycoprotein serine protease that contributes to extracellular matrix degradation and tissue remodelling. Also known as prolyl endopeptidase FAP, with the alias DPPIV, it belongs to the DASH family. Browse Assay Genie's current range of Fibroblast Activation Protein research reagents below, or read on for the biology behind the target.
Fibroblast Activation Protein is a serine protease that takes part in extracellular matrix degradation and is involved in tissue remodelling, fibrosis, wound healing, inflammation and tumour growth. Both the plasma membrane and soluble forms show post-proline cleaving endopeptidase activity, with a marked preference for Ala/Ser-Gly-Pro-Ser/Asn/Ala sequences. Reported substrates include alpha-2-antiplasmin (SERPINF2) and SPRY2. It also degrades gelatin and heat-denatured type I collagen, but not native type I or IV collagen, fibronectin, laminin, vitronectin, tenascin, fibrin or casein.
FAP also has dipeptidyl peptidase activity, hydrolysing the prolyl bond two residues from the N-terminus of synthetic dipeptide substrates when the penultimate residue is proline. Natural neuropeptide substrates for this activity include neuropeptide Y (NPY), peptide YY (PYY), substance P (TAC1) and brain natriuretic peptide 32 (NPPB). At the plasma membrane, FAP associates with DPP4, PLAUR or integrins and contributes to pericellular proteolysis of the matrix, promoting cell adhesion, migration and invasion. It is found at the cell surface, in lamellipodia, invadopodia and ruffles, and as a secreted form. The FAP gene encodes a homodimeric integral membrane gelatinase of the peptidase S9B family, and alternatively spliced transcript variants encoding different isoforms have been described.
Expression is selective: FAP is found in reactive stromal fibroblasts of epithelial cancers, granulation tissue of healing wounds, and malignant cells of bone and soft tissue sarcomas. It is thought to help control fibroblast growth and epithelial-mesenchymal interactions during development, tissue repair and epithelial carcinogenesis. Its disease roles are context dependent. It promotes tumour progression by increasing angiogenesis and collagen fibre degradation and by reducing antitumour immune response, and it drives glioma invasion by degrading brevican. In melanocytic cells it acts as a tumour suppressor independently of its protease activity.
FAP is expressed in reactive stromal fibroblasts of epithelial cancers and enhances tumour growth by promoting angiogenesis and reducing antitumour immune response.
Its post-proline endopeptidase activity degrades gelatin and denatured collagen, supporting pericellular proteolysis, cell adhesion, migration and invasion.
FAP is found in granulation tissue of healing wounds and is implicated in tissue remodelling, fibrosis and inflammation.
FAP is present in malignant cells of bone and soft tissue sarcomas and promotes invasion in melanoma and glioma through matrix degradation.
FAP is a cell surface serine protease with post-proline endopeptidase and dipeptidyl peptidase activity. It degrades gelatin and denatured collagen, contributes to pericellular proteolysis, and is involved in tissue remodelling, wound healing, fibrosis, inflammation and tumour growth.
The approved name is fibroblast activation protein alpha, previously fibroblast activation protein, alpha. UniProt lists it as prolyl endopeptidase FAP, and DPPIV appears as an alias. NCBI reports alternatively spliced transcript variants that encode different isoforms.
A mouse ortholog, Fap, is recorded for this gene. FAP belongs to the peptidase S9B family and the DASH family. Check the datasheet of any product for its validated reactivity before planning cross-species work.
Binding partners, substrates and peptide hormones linked to fibroblast activation protein function in matrix remodelling and cancer.
Gene and protein annotations from HGNC, NCBI Gene and UniProt Q12884; product specifications from Assay Genie datasheets.