Important in the maintenance of hemostasis, it promotes adhesion of platelets to the sites of vascular injury by forming a molecular bridge between sub-endothelial collagen matrix and platelet-surface receptor complex GPIb-IX-V. Also acts as a chaperone for coagulation factor VIII, delivering it to the site of injury, stabilizing its heterodimeric structure and protecting it from premature clearance from plasma. Defects in VWF are the cause of von Willebrand disease type 1 (VWD1). A common hemorrhagic disorder due to defects in von Willebrand factor protein and resulting in impaired platelet aggregation. Von Willebrand disease type 1 is characterized by partial quantitative deficiency of circulating von Willebrand factor, that is otherwise structurally and functionally normal. Clinical manifestations are mucocutaneous bleeding, such as epistaxis and menorrhagia, and prolonged bleeding after surgery or trauma. Defects in VWF are the cause of von Willebrand disease type 2 (VWD2). A hemorrhagic disorder due to defects in von Willebrand factor protein and resulting in impaired platelet aggregation. Von Willebrand disease type 2 is characterized by qualitative deficiency and functional anomalies of von Willebrand factor. It is divided in different subtypes including 2A, 2B, 2M and 2N (Normandy variant). The mutant VWF protein in types 2A, 2B and 2M are defective in their platelet- dependent function, whereas the mutant protein in type 2N is defective in its ability to bind factor VIII. Clinical manifestations are mucocutaneous bleeding, such as epistaxis and menorrhagia, and prolonged bleeding after surgery or trauma. Defects in VWF are the cause of von Willebrand disease type 3 (VWD3). A severe hemorrhagic disorder due to a total or near total absence of von Willebrand factor in the plasma and cellular compartments, also leading to a profound deficiency of plasmatic factor VIII. Bleeding usually starts in infancy and can include epistaxis, recurrent mucocutaneous bleeding, excessive bleeding after minor trauma, and hemarthroses. Note: This description may include information from UniProtKB.
Protein type: Secreted; Cell adhesion; Motility/polarity/chemotaxis; Secreted, signal peptide; Extracellular matrix
Cellular Component: extracellular matrix; proteinaceous extracellular matrix; endoplasmic reticulum; extracellular region; external side of plasma membrane
Molecular Function: integrin binding; collagen binding; identical protein binding; protein binding; protein homodimerization activity; protease binding; chaperone binding; immunoglobulin binding; protein N-terminus binding; glycoprotein binding
Biological Process: platelet activation; extracellular matrix organization and biogenesis; platelet degranulation; hemostasis; response to wounding; liver development; cell adhesion; blood coagulation; blood coagulation, intrinsic pathway; protein homooligomerization; cell-substrate adhesion; placenta development
SS: The number of records in which this modification site was determined using site-specific methods. SS methods include amino acid sequencing, site-directed mutagenesis, modification site-specific antibodies, specific MS strategies, etc.