COMPLEX PROTEIN-COMPOSITION OF ISOLATED FOCAL ADHESIONS - A 2-DIMENSIONAL GEL AND DATABASE ANALYSIS

Current ideas about the composition of the focal adhesion complexes in cultured cells are based mainly on indirect immunocytochemical data. We here report a two-dimensional (2-D) gel electrophoresis analysis of the focal adhesion associated-structures that remain in the growth su bstrate after removal of cells by mechanical shearing. Many proteins a dditional to the known adhesion proteins, and in higher abundance, cou ld be identified. Using selective extraction procedures, employing det ergent or gelsolin, these could be classified as either membrane-assoc iated, actin-associated or both. Cross correlation of these polypeptod e patterns with a 2-D gel database allowed identification of some prot eins, not previously considered as resident of focal adhesions. The da ta point to a more complex make up of focal adhesions than formerly su pposed.