Fibronectin is not present in the focal adhesions formed between normal cultured fibroblasts and their substrata.
AUTOR(ES)
Chen, W T
RESUMO
Fibronectin is an extracellular matrix protein that has been implicated in the spreading and adhesion of cultured fibroblasts to their substrata. In this paper, double immunoelectron microscopic labeling experiments for fibronectin and for concanavalin A-binding proteins on the cell surface were carried out on ultrathin frozen sections of cultures of embryonic chicken heart fibroblasts. On cross sections though the focal adhesions of the cell to the substratum there was substantial labeling for concanavalin A-binding proteins but no detectable labeling for fibronectin, whereas both the binding proteins and fibronectin were extensively labeled elsewhere on the cell surface and substratum. These results demonstrate that fibronectin is not present within the sites of focal adhesions. Therefore, the functions of fibronectin in cell spreading and adhesion are not directly mediated through its binding at focal adhesion sites. An alternative model is presented which can account for such fibronectin functions.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=350494Documentos Relacionados
- Interference reflection microscopic study of sites of association between gliding bacteria and glass substrata.
- Adherence of Pseudomonas aeruginosa to hydrophilic contact lenses and other substrata.
- Phosphotyrosine-containing proteins are concentrated in focal adhesions and intercellular junctions in normal cells.
- Regulation of insulin mRNA abundance and adenylation: dependence on hormones and matrix substrata.
- Corrugated attachment membrane in WI-38 fibroblasts: alternating fibronectin fibers and actin-containing focal contacts.