Fibronectin, the extracellular glue

Fibronectin is an extracellular matrix protein that is present during periods of change within tissues. It is upregulated and necessary in a number of developmental contexts, and it is also present during pathological progression of tissues and during wound healing. Thus, it has been studied in a broad number of contexts from basic science to pathology. One of the unique features of fibronectin is its ability to specifically bind a large number of molecules including other components of the extracellular matrix, signaling molecules, and cell adhesion molecules. Cellular interactions with fibronectin lead to bidirectional crosstalk that directs cell function and also leads to cell-dependent changes in the extracellular matrix. Interestingly, fibronectin exists in a functional form composed of fibers that are nm to μm in diameter that is highly interwoven, and fibronectin molecules that constitute this material have a labile molecular conformation that can be altered through binding of allosteric partners and strain resulting from application of cell contractile forces. This review focuses on summarizing the many binding partners for fibronectin such as ECM proteins, growth factors, and synthetic binding partners with a particular interest in binding partners whose adhesiveness is impacted by the molecular conformation of the fibronectin fibers.