Fibronectin

Fibronectin is a high-molecular weight (~440kDa) glycoprotein found in the extracellular matrix and in blood plasma. It is made up of two subunits that vary in size between 235-270 kDa, due to alternate splicing, (Figure 1). The secreted fibronectin dimer is a soluble protein which polymerizes to higher order fibrils in the ECM. Fibronectin plays a major role in cell adhesion, growth, migration, actin dynamics and differentiation, and it is important for processes such as wound healing and embryonic development (2).   Many of these functions are mediated through fibronectin binding to integrin receptor proteins (2). Altered fibronectin expression, degradation, and organization has been associated with a number of pathologies, including cancer and fibrosis (3).

In addition to integrins, fibronectin also binds extracellular matrix components such as collagen, fibrin and heparan sulfate proteoglycans (e.g. syndecans).

Read more about assays used to study Fibronectin (Click here).

References

1. Pankov R, Yamada KM . 2002. "Fibronectin at a glance". Journal of Cell Sci. 20 115: 3861-3863.
2. Williams CM, Engler AJ, Slone RD, Galante LL, Schwarzbauer JE. 2008. “Fibronectin expression modulates mammary epithelial cell proliferation during acinar differentiation. Cancer Research.  9  68: 3185-8192.
3. Artym VV. Et al. 2009. ECM degradation assay for analyzing local cell invasion.  Methods in molecular biology, Extracellular matrix protocols, vol. 522: 211-219.Humana Press.