Analysis of fibronectin receptor function with monoclonal antibodies: roles in cell adhesion, migration, matrix assembly, and cytoskeletal organization.
Open Access
- 1 August 1989
- journal article
- research article
- Published by Rockefeller University Press in The Journal of cell biology
- Vol. 109 (2), 863-875
- https://doi.org/10.1083/jcb.109.2.863
Abstract
We have developed two rat mAbs that recognize different subunits of the human fibroblast fibronectin receptor complex and have used them to probe the function of this cell surface heterodimer. mAb 13 recognizes the integrin class 1 beta polypeptide and mAb 16 recognizes the fibronectin receptor alpha polypeptide. We tested these mAbs for their inhibitory activities in cell adhesion, spreading, migration, and matrix assembly assays using WI38 human lung fibroblasts. mAb 13 inhibited the initial attachment as well as the spreading of WI38 cells on fibronectin and laminin substrates but not on vitronectin. Laminin-mediated adhesion was particularly sensitive to mAb 13. In contrast, mAb 16 inhibited initial cell attachment to fibronectin substrates but had no effect on attachment to either laminin or vitronectin substrates. When coated on plastic, both mAbs promoted WI38 cell spreading. However, mAb 13 (but not mAb 16) inhibited the radial outgrowth of cells from an explant on fibronectin substrates. mAb 16 also did not inhibit the motility of individual fibroblasts on fibronectin in low density culture and, in fact, substantially accelerated migration rates. In assays of the assembly of an extracellular fibronectin matrix by WI38 fibroblasts, both mAbs produced substantial inhibition in a concentration-dependent manner. The inhibition of matrix assembly resulted from impaired retention of fibronectin on the cell surface. Treatment of cells with mAb 16 also resulted in a striking redistribution of cell surface fibronectin receptors from a streak-like pattern to a relatively diffuse distribution. Concomitant morphological changes included decreases in thick microfilament bundle formation and reduced adhesive contacts of the streak-like and focal contact type. Our results indicate that the fibroblast fibronectin receptor (a) functions in initial fibroblast attachment and in certain types of adhesive contact, but not in the later steps of cell spreading; (b) is not required for fibroblast motility but instead retards migration; and (c) is critically involved in fibronectin retention and matrix assembly. These findings suggest a central role for the fibronectin receptor in regulating cell adhesion and migration.This publication has 61 references indexed in Scilit:
- Monoclonal antibodies to distinctive epitopes on the α and β subunits of the fibronectin receptorExperimental Cell Research, 1988
- Extracellular matrix receptors, ECMRII and ECMRI, for collagen and fibronectin correspond to VLA‐2 and VLA‐3 in the VLA family of heterodimersJournal of Cellular Biochemistry, 1988
- Comparison of cDNA-derived protein sequences of the human fibronectin and vitronectin receptor .alpha.-subunits and platelet glycoprotein IIbBiochemistry, 1987
- Regulation of fibronectin receptor distribution by transformation, exogenous fibronectin, and synthetic peptides.The Journal of cell biology, 1986
- Characterization of a 140-kD avian cell surface antigen as a fibronectin-binding molecule.The Journal of cell biology, 1986
- Selective Inhibition of Fibronectin-Mediated Cell Adhesion by Monoclonal Antibodies to a Cell-Surface GlycoproteinScience, 1985
- Binding of plasma fibronectin to cell layers of human skin fibroblasts.The Journal of cell biology, 1983
- “Western Blotting”: Electrophoretic transfer of proteins from sodium dodecyl sulfate-polyacrylamide gels to unmodified nitrocellulose and radiographic detection with antibody and radioiodinated protein AAnalytical Biochemistry, 1981
- Immunological characterization of a major transformation-sensitive fibroblast cell surface glycoprotein. Localization, redistribution, and role in cell shape.The Journal of cell biology, 1978
- Cleavage of Structural Proteins during the Assembly of the Head of Bacteriophage T4Nature, 1970