Extracellular adhesion glycoprotein

J. A. McDonald, B. J. Baum, D, M. Roseubeg, J. A. Kdman,S. C. Brin, and R. G. Crystal. Destruction of a imJor extracellular adhesive glycoprotein (fibronccrin) of human fibroblasts by neutral proteases from polymorphonuclear leukocyte granules. Lab. Invest. 40350 (1979). 

Fibronectin. Fibronectin is expressed in and around neoplastic blood vessels during tumor growth and angiogenesis. Fibronectin is an extracellular adhesion glycoprotein that binds to integrin receptors and mediates interactions between cells and extracellular matrix components. Antibodies against fibronectin have been studied for targeting. " ... 

Fibronectin (FN), an extracellular adhesive glycoprotein mediating cell-matrix adhesion. FN is a dimer consisting of two similar (but not identical) subunits, each with almost 2500 residues. The subunits are joined together by a pair of disulfide bonds located near their C-termini. Each polypeptide chain is folded into a series of globular domains connected by flexible... 

The activities of the purple fluid of the sea hare Aplysia dactylomela, such as toxic, antimicrobial and hemagglutinating properties, have been attributed to a substance of protein nature [332], Proteoglycans and adhesive glycoproteins present in the extracellular matrix of vertebrates, have also been reported in sponges. These molecules are probably involved in the cell adhesion systems of sponges [333], Recently, novel marine proteins have been reported, such as silicatein from sponge biosilica [334], and a metallothionein protein from the marine alga Fuats vesiculosus [335], Metallothioneins have also been isolated from Arctic... 

The evidence is increasing that glycosylation of integrins plays important modulatory roles in the function of these molecules. In other studies it appears that the glycosylation of at least one extracellular matrix glycoprotein, namely laminin, is important in cellular adhesion mediated by integrins. So far most information on the role of carbohydrates in integrin-mediated adhesive interactions has been obtained for the fibronectin receptors... 

The extracellular matrix is connected to cells by adhesive glycoproteins, fibronectin, and laminin, which bind to integrins in the plasma membrane. 

Fibronectin A family of closely related adhesion glycoproteins, Mj 200,000-250,000, which arise by the alternative splicing of the precursor mRNA. F. is found both as a cell surface protein of the extracellular matrix (also known as Cell Surface Protein, Galac-toprotein A, Large External Transformation Sensitive Protein, Surface Fibroblast Antigen, and Zeta or Z Protein), and in plasma. Plasma fibronectin is incorporated into fibrin clots and is cross-linked to the fibrin, probably via a Gln-Lys transamidation reaction. 

The role of fibronectin, an adhesion glycoprotein present on the surface of cells in connective tissue matrices and in extracellular fluids, has been reviewed with reference to malignant transformation, embryonic diflerentiation, and the function of the reticuloendothelial system. Chemical and physical characteristics of fibronectin and the role of fibronectin and other matrix components in malignant transformation have been surveyed. ... 

Many transmembrane proteins that mediate intracellular signaling form complexes with both intra- and extracellular proteins. For example, neural cell adhesion molecules (NCAMs) are cell-surface glycoproteins (Ch. 7). The extracellular domains of NCAMs can activate fibroblast growth factor receptors when clustered by reaction with NCAM antibodies [4] or by homotypic binding to domains of adjacent cells (see Fig. 7-2). Activation was found to sequester a complex of NCAM, (31 spectrin and PKC(32 into rafts, as defined by the operational criteria discussed on p. 28. 

FIGURE 7-1 The immunoglobulin (Ig) gene family of molecules. Several varieties of Ig domain-containing molecules are contained within the Ig gene superfamily. Most are type I membrane proteins some have only Ig domains or other moieties that may convey function (see text). V, variable Ig domain C, constant Ig domain MAG, myelin-associated glycoprotein NCAM, neural cell adhesion molecule GPI, glycosylphosphatidyl-inositol EC, extracellular domain FN, fibronectin. 

Cadherins are calcium-dependent cell-cell adhesion molecules. Most cadherins are transmembrane glycoproteins consisting of five repeated extracellular... 

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