Fibronectin-binding surface proteins are found in many bacterial species. Most strains of Streptococcus pyogenes, a major human pathogen, express the fibronectin-binding protein F1, which promotes bacterial adherence to and entry into human cells. In this study, the role of fibronectin in S. pyogenes virulence was investigated by introducing the protein F1 gene in an S. pyogenes strain lacking ...

Cell adhesion to the extracellular matrix is important in many biological processes. Various ligands and cell surface receptors have been defined. In vitro cell adhesion to matrix proteins and to other 'adhesion' proteins is generally measured on plastic culture substrates. We have found that the presence of low levels of adhesion proteins, e.g. fibronectin, together with high concentrations of...

Communication between cells and the extracellular matrix (ECM) is critical for regulation of cell growth, survival, migration, and differentiation. Remodeling of the ECM can occur under normal physiological conditions, as a result of tissue injury, and in certain pathological conditions. ECM remodeling leads to alterations in ECM composition and organization that can alter many aspects of cell ...

An enterotoxigenic strain of Escherichia coli, B34289c, has been shown to bind the N-terminal region of fibronectin with high affinity (G. Fröman, L. M. Switalski, A. Faris, T. Wadström, and M. Höök, J. Biol. Chem. 259:14899-14905, 1984). We now report that this strain also binds collagen. The binding of 125I-labeled type II collagen to bacteria was time dependent and reversible. Bacteria expre...

In previous studies, Staphylococcus aureus has been shown to bind fibronectin (P. Kuusela, Nature (London) 276:718-720, 1978), an interaction that may be important in bacterial attachment and opsonization. Recently some strains of streptococci of serological groups A, C, and G were also found to bind fibronectin. The binding to one selected strain of Streptococcus pyogenes has been characterize...

Using a novel coverslip-transfer culture technique, we recently demonstrated that primitive erythroid burst-forming units (BFU-E) can migrate, proliferate, and differentiate in intimate association with stromal fibroblastoid cells in the presence of serum proteins and erythropoietin. No other exogenous hemopoietic growth factors are required. Most of the colonies that develop in this system are...

An expression system for studying epitopes of adhesion proteins based on fusion of gene fragments into fliC(H7) of Escherichia coli is described. We constructed the system by an in-frame insertion of DNA fragments encoding one, two or three of the fibronectin-binding D repeats present in the fibronectin-binding protein A (FnBPA) of Staphylococcus aureus, into the fliC(H7) gene region encoding t...

The vitronectin receptor (alpha v beta 3) is a member of the integrin superfamily of adhesive protein receptors that mediate a wide spectrum of adhesive cellular interactions, including attachment to vitronectin, von Willebrand factor, fibrinogen, and thrombospondin. We have studied the binding of fibronectin to the purified vitronectin receptor, and the role of this receptor in the attachment ...

Mn2+ at low (microM) concentrations fulfils the divalent cation requirement for spreading of BHK21 cells on fibronectin. At much higher concentrations, Mn2+ (and to a small extent also Mg2+) induces spreading on haemoglobin, not normally an adhesive protein. Since high Mn2+ also induces spreading of BHK variants unresponsive to exogenous fibronectin, it is unlikely to be acting as a cofactor fo...

Human pulmonary alveolar macrophages synthesized and secreted several characteristic high molecular weight proteins for at least 7 d in vitro. Immunoprecipitates of medium and cell lysates from metabolically labeled cultures with specific anti-human plasma fibronectin IgG contained one major labeled polypeptide of molecular weight 440,000 (unreduced) or 220,000 (reduced). An identical polypepti...