Fibronectin (FN) assembly into a fibrillar extracellular matrix is a stepwise process requiring participation from multiple FN domains. Fibril formation is regulated in part by segments within the first seven type III repeats (III1-7). To define the specific function(s) of this region, recombinant FNs (recFNs) containing an overlapping set of deletions were tested for the ability to assemble in...

Mov13 fibroblasts, which do not express endogenous alpha 1(I) collagen chains due to a retroviral insertion, were used to study the role of type I collagen in the process of fibronectin fibrillogenesis. While Mov13 cells produced a sparse matrix containing short fibronectin fibrils, transfection with a wild type pro alpha 1(I) collagen gene resulted in the production of an extensive matrix cont...

Monoclonal antibodies against fibronectin were used to locate the gelatin-binding and cell-attachment regions of plasma fibronectin at an ultrastructural level. A total of 23 hybridomas were generated using mice immunized with either intact fibronectin or a 40 000 Mr gelatin-binding fibronectin fragment. One of these antibodies (D9b) strongly inhibited the interaction of radio-labelled fibronec...

Recent studies suggested that trafficking of hematopoietic progenitor cells is related to cell cycle status. We studied whether adhesion of progenitor cells to extracellular matrix proteins was modulated by cell cycle transit. Mobilized peripheral blood CD34+ cells were stimulated ex vivo for 48 hours with stem cell factor, flt-3 ligand, and thrombopoietin and fractionated by adhesion to fibron...

Background. Matrix Gla protein (MGP) is a vitamin K-dependent, extracellular matrix protein. MGP is a calcification inhibitor of arteries and cartilage. However MGP is synthesized in many tissues and is especially enriched in embryonic tissues and in cancer cells. The presence of MGP in those instances does not correlate well with the calcification inhibitory role. This study explores a potenti...

We investigated the impacts of sarA and agr on fnbA expression and fibronectin-binding capacity in Staphylococcus aureus in vitro and in experimental endocarditis. Although sarA up-regulated and agr down-regulated both fnbA expression and fibronectin binding in vitro and in vivo, fnbA expression was positively regulated in the absence of both global regulators. Thus, additional regulatory loci ...

Of ten different cell lines examined, three showed distinct attachment and spreading on collagen IV substrates, and neither attachment nor spreading was enhanced by adding soluble laminin or fibronectin. This reaction was not inhibited by cycloheximide or antibodies to laminin, indicating a direct attachment to collagen IV without the need of mediator proteins. Cell-binding sites were localized...

The possibility that fibronectin on the surface of oropharyngeal cells may serve as a receptor for the binding of group A streptococci (Streptococcus pyogenes) was investigated. Purified human plasma fibronectin inhibited the adherence of group A streptococci to oral epithelial cells in a dose-dependent manner. The relative amounts of fibronectin available on oral epithelial cells correlated cl...