1E88, 1E8B, 1FBR, 1FNA, 1FNF, 1FNH, 1J8K, 1O9A, 1OWW, 1Q38, 1QGB, 1QO6, 1TTF, 1TTG, 2CG6, 2CG7, 2CK2, 2CKU, 2EC3, 2FN2, 2FNB, 2GEE, 2H41, 2H45, 2HA1, 2OCF, 2RKY, 2RKZ, 2RL0, 3CAL, 3EJH, 3GXE, 3M7P, 3MQL, 3R8Q, 3ZRZ, 4GH7, 4JE4, 4JEG, 4LXO, 4MMX, 4MMY, 4MMZ, 4PZ5, 2N1K, 5DC4, 5DC0, 5DC9, 3T1W233514268ENSG00000115414ENSMUSG00000026193P02751P11276NM_054034NM_212474NM_212475NM_212476NM_212478NM_212482NM_001365517NM_001365518NM_001365519NM_001365520NM_001365521NM_001365522NM_001365523NM_001365524NM_001276413NM_010233NP_473375NP_997639NP_997641NP_997643NP_997647NP_001352446NP_001352447NP_001352448NP_001352449NP_001352450NP_001352451NP_001352452NP_001352453NP_001293058.1NP_001293059.1NP_001293061.1NP_001263342NP_034363Fibronectin is a high-molecular weight (~500-~600 kDa)[5] glycoprotein of the extracellular matrix that binds to membrane-spanning receptor proteins called integrins.

[6] Fibronectin also binds to other extracellular matrix proteins such as collagen, fibrin, and heparan sulfate proteoglycans (e.g. syndecans).

Fibronectin exists as a protein dimer, consisting of two nearly identical monomers linked by a pair of disulfide bonds.

[6] The fibronectin protein is produced from a single gene, but alternative splicing of its pre-mRNA leads to the creation of several isoforms.

[6] Altered fibronectin expression, degradation, and organization has been associated with a number of pathologies, including cancer, arthritis, and fibrosis.

[7][8] Fibronectin exists as a protein dimer, consisting of two nearly identical polypeptide chains linked by a pair of C-terminal disulfide bonds.

The absence of disulfide bonds in type III modules allows them to partially unfold under applied force.

[13][14] Along with fibrin, plasma fibronectin is deposited at the site of injury, forming a blood clot that stops bleeding and protects the underlying tissue.

These fragments of fibronectin are believed to enhance the binding of α4β1 integrin-expressing cells, allowing them to adhere to and forcefully contract the surrounding matrix.

Similarly, the absence of a normal fibronectin matrix in developing amphibians causes defects in mesodermal patterning and inhibits gastrulation.

[16] Fibronectin is also found in normal human saliva, which helps prevent colonization of the oral cavity and pharynx by pathogenic bacteria.

This fibronectin-fibronectin interaction enables the soluble, cell-associated fibrils to branch and stabilize into an insoluble fibronectin matrix.

A transmembrane protein, CD93, has been shown to be essential for fibronectin matrix assembly (fibrillogenesis) in human dermal blood endothelial cells.

The adhesion of lung carcinoma cells to fibronectin enhances tumorigenicity and confers resistance to apoptosis-inducing chemotherapeutic agents.

These observations suggest that fibronectin may promote lung tumor growth/survival and resistance to therapy, and it could represent a novel target for the development of new anticancer drugs.

[26] Plasma fibronectin levels are decreased in acute inflammation or following surgical trauma and in patients with disseminated intravascular coagulation.

Based on the size and histological staining characteristics of the fibrils, it is likely that at least in part they are composed of type III collagen (reticulin).

Disulfide-bonded multimerization of fibronectin in the cell layer occurs by disulfide bond exchange in the disulfide-rich amino-terminal one-third of the molecule.