Fibronectins

Fibronectin is a high-molecular-weight glycoprotein that is found in the extracellular matrix of animal tissues. It was first discovered in 1979 by Piers C. Lawrence, who named it after its fibrous appearance under the electron microscope. Fibronectin is a versatile protein that plays a crucial role in various biological processes, including cell adhesion, migration, proliferation, and differentiation. It is composed of three distinct domains: the cell-binding domain, the heparin-binding domain, and the gelatin-binding domain. The cell-binding domain is responsible for the interaction between fibronectin and integrins, a family of cell surface receptors. This interaction is essential for cell adhesion to the extracellular matrix and for the transmission of signals from the extracellular environment to the cell interior. The heparin-binding domain mediates the interaction between fibronectin and heparin sulfate proteoglycans, which are components of the extracellular matrix. This interaction is important for the organization and stability of the extracellular matrix. The gelatin-binding domain binds to gelatin, a denatured form of collagen, and is involved in the assembly and organization of the extracellular matrix. Fibronectin is also involved in wound healing, angiogenesis, and tumor metastasis. It can promote the migration and invasion of tumor cells, which is why it is often targeted in cancer therapy. In addition, fibronectin is a useful tool in biomedical research, as it can be used to coat surfaces for cell culture and to study cell-matrix interactions. Overall, fibronectin is a multifunctional protein that plays a vital role in the structure and function of the extracellular matrix and in various biological processes.