The structure of fibronectin and its role in cellular adhesion

Abstract

Fibronectin is a large, adhesive glycoprotein which is found in a number of locations, most notably on cell surfaces, in extracellular matrixes, and in blood. Fibronectin had been detected in all vertebrates tested and in many invertebrates. Its presence in sponges is significant because this suggests that fibronectin may have appeared very early in evolution, possibly with the most primitive multicellular organisms. Cellular and plasma fibronectins have many striking similarities. However, the locations of the polypeptide chain differences between these two proteins indicate that plasma fibronectin cannot be derived from cellular fibronectin by means of simple post-translational proteolysis. Instead, these different types of fibronectin may be products of different genes or of differentially spliced messenger RNA molecules. Amniotic fluid fibronectin is possibly a third form of the protein. Cellular and plasma fibronectins are composed of at least six protease-resistant domains which contain specific binding sites for actin, gelatin, heparin, Staphylococcus aureus, transglutaminase, fibrin, DNA, and a cell surface receptor. The relative locations of these domains have been mapped in the primary structure of fibronectin. The cell surface receptor for fibronectin has not been positively identified, but may be a glycoprotein, a glycolipid, or a complex of the two. Although cell-substratum adhesion is mediated by fibronectin, the locations of the areas of closest approach of the cell to the substratum (the adhesion plaques) and fibronectin are not coincident under conditions of active cell growth. Under conditions of cell growth arrest in low serum concentrations, some fibronectin may become localized at the adhesion plaques. Models describing the domain structure of fibronectin and the molecular organization of the adhesion plaque area are presented.

Influence of plasma and ultraviolet treatment of zirconia on initial attachment of human oral keratinocytes: Expressions of laminin γ2 and integrin β4

“…A possible explanation for the differences between the results of these reports and the present study can be linked to the differences in the extracellular matrix binding the cells. In the osteoblasts, fibronectin is primarily responsible for the adhesion between the substrate and cells 19,20) . In contrast, laminin is primarily related to the adhesion between the substrate and keratinocytes in addition to the fibronectin 21) .…”

The Role of Fibronectin in Pulmonary Gene Transfer Following Intravenous Administration of Lipoplex in Mice

“…However, it was reported that fibronectin has DNAbinding domains and their structures have been identified. 20,21) Therefore, the binding of fibronectin to pDNA is likely to be an important mechanism for the interaction between lipoplex and fibronectin. Fetuin is known as an α2-HS glycoprotein and shows opsonin activity.…”

Behavior of osteoblast-like cells on fibronectin or BMP-2 immobilized surface

“…It has been reported that precoating titanium with fi bronectin enhanced the adhesion of cells to the titanium (1,19). The biological function of fi bronectin was evaluated by counting initially attached cells (7,9).…”

“…Fibronectin is known to play an important role in governing the interactions of biomaterials with their surrounding matrices (1,19). It was also reported that precoating materials with fi bronectin enhanced cell adhesion to the substrate (4,5).…”