, The SMB domain (yellow) in complex with PAI-1
Ortholog search: PDBe, RCSB
List of PDB id codes
1OC0, 1S4G, 1SSU, 2JQ8, 3BT1, 3BT2
VTN; V75; VN; VNT
OMIM: 193190 MGI: 98940 HomoloGene: 532 ChEMBL: 1075314 GeneCards: VTN Gene
• scavenger receptor activity, • integrin binding, • protein binding, • heparin binding, • polysaccharide binding,
• extracellular region, • extracellular space, • extracellular matrix, • alphav-beta3 integrin-vitronectin complex,
• immune response, • cell adhesion, • cell-matrix adhesion, • negative regulation of endopeptidase activity, • positive regulation of smooth muscle cell migration, • negative regulation of blood coagulation, • extracellular matrix organization, • positive regulation of vascular endothelial growth factor receptor signaling pathway, • positive regulation of protein binding, • cell adhesion mediated by integrin, • positive regulation of receptor-mediated endocytosis, • positive regulation of peptidyl-tyrosine phosphorylation, • smooth muscle cell-matrix adhesion, • positive regulation of wound healing,
Sources: Amigo / QuickGO
RNA expression pattern
More reference expression data
26.69 - 26.7 Mb
78.5 - 78.5 Mb
Vitronectin also known as VTN is a protein that in humans is encoded by the VTN gene.
The protein encoded by this gene is a member of the pexin family. Vitronectin is an abundant glycoprotein found in serum and the extracellular matrix and promotes cell adhesion and spreading, inhibits the membrane-damaging effect of the terminal cytolytic complement pathway, and binds to several serpins (serine protease inhibitors). It is a secreted protein and exists in either a single chain form or a clipped, two chain form held together by a disulfide bond. Vitronectin has been speculated to be involved in hemostasis and tumor malignancy.
4 External links,
Vitronectin is a 75 kDa glycoprotein, consisting of 459 amino acid residues. About one-third of the protein's molecular mass is composed of carbohydrates. On occasion, the protein is cleaved after arginine 379, to produce two-chain vitronectin, where the two parts are linked by a disulfide bond. No high resolution structure has been determined experimentally yet, except for the N-terminal domain.
The protein consists of three domains:
The N-terminal Somatomedin B domain (1-39),
A central domains with hemopexin homology (131-342),
A C-terminal domain (residues 347-459) also with hemopexin homology.,
Several structures has been reported for the Somatomedin B domain. The protein was initially crystallized in complex with one of its physiological binding partners: the Plasminogen activator inhibitor-1 (PAI-1) and the structure solved for this complex. Subsequently two groups reported NMR structures of the domain.
The Somatomedin B domain is a close-knit disulfide knot, with 4 disulfide bonds within 35 residues. Different disulfide configurations had been reported for this domain but this ambiguity has been resolved by the crystal structure.
Homology models have been built for the central and C-terminal domains.
The somatomedin B domain of vitronectin binds to plasminogen activator inhibitor-1 (PAI-1), and stabilizes it. Thus vitronectin serves to regulate proteolysis initiated by plasminogen activation. In addition, vitronectin is a component of platelets and is, thus, involved in hemostasis. Vitronectin contains an RGD (45-47) sequence, which is a binding site for membrane-bound integrins, e.g., the vitronectin receptor, which serve to anchor cells to the extracellular matrix. The Somatomedin B domain interacts with the urokinase receptor, and this interaction has been implicated in cell migration and signal transduction. High plasma levels of both PAI-1 and the urokinase receptor have been shown to correlate with a negative prognosis for cancer patients. Cell adhesion and migration are directly involved in cancer metastasis, which provides a probable mechanistic explanation for this observation.