Fibronectin-cell surface interactions.

Fibronectins are a group of closely related proteins that are found in body fluids and tissue extracellular matrices. Fibronectins play important roles in the maintenance of hemostasis and in the organization of developing tissues. The interaction of cells with fibronectin probably involves specific cell-surface molecules. Two distinct receptors for fibronectin have been postulated. One receptor, a 140-kilodalton complex, has been identified in a variety of cell types and is believed to mediate the attachment of cells to fibronectin-coated substrata. The existence of a second receptor has been proposed but it has not been identified. This receptor may function in the assembly of soluble fibronectin into the extracellular matrix. In this paper some of the recent developments in the identification and characterization of fibronectin-binding molecules on the surfaces of eukaryotic cells are outlined.