Cell adhesion or integrin clustering increases phosphorylation of a focal adhesion-associated tyrosine kinase

• Published in: The Journal of biological chemistry 1992-11, Vol.267 (33), p.23439-23442
• Main Authors: KORNBERG, L, SHELTON EARP, H, THOMAS PARSONS, J, SCHALLER, M, JULIANO, R. L
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Blotting, Western; Cell Adhesion; Cell Adhesion Molecules - isolation & purification; Cell Adhesion Molecules - metabolism; Cell physiology; Cells, Cultured; Chick Embryo; chickens; Electrophoresis, Polyacrylamide Gel; fibroblasts; Fibroblasts - physiology; fibronectin; Fibronectins - metabolism; Focal Adhesion Kinase 1; Focal Adhesion Protein-Tyrosine Kinases; focal adhesion-associated tyrosine kinase; Fundamental and applied biological sciences. Psychology; Humans; integrin; Integrins - metabolism; KB Cells; Kinetics; mediation; Molecular and cellular biology; Molecular Weight; Phosphorylation; Protein-Tyrosine Kinases - isolation & purification; Protein-Tyrosine Kinases - metabolism; receptors; Signal Transduction; tyrosine
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1016/s0021-9258(18)35853-8

We have recently shown that changes in tyrosine phosphorylation of a 130-kDa protein(s) (pp130) may be involved in integrin signaling (Kornberg, L., Earp, H.S., Turner, C., Prokop, and Juliano, R. L. (1991) Proc. Natl. Acad. Sci. U.S.A. 88, 8392-8396). One component of the pp130 protein complex reacts with an antibody generated against p125fak, which is a focal contact-associated tyrosine kinase (Schaller, M.D., Borgman, C. A., Cobb, B. S., Vines, R. R., Reynolds, A. B., and Parsons, J. T. (1992) Proc. Natl. Acad. Sci. U.S.A. 89, 5192-5196). Both antibody-mediated integrin clustering and adhesion of KB cells to fibronectin leads to increased tyrosine phosphorylation of p125fak. The phosphorylation of p125fak is coincident with adhesion of cells to fibronectin and is maximal prior to cell spreading. Tyrosine phosphorylation of p125fak is induced when KB cells are allowed to adhere to fibronectin, collagen type IV, or laminin, but is not induced on polylysine. When KB cells are subjected to indirect immunofluorescence microscopy, p125fak colocalizes with talin in focal contacts. These data provide additional evidence that tyrosine kinases are involved in integrin signaling.