Vinculin promotes cell spreading by mechanically coupling integrins to the cytoskeleton

摘要: Mouse F9 embryonic carcinoma 5.51 cells that lack the cytoskeletal protein vinculin spread poorly on extracellular matrix compared with wild-type or two vinculin-transfected clones (5.51Vin3 and Vin4; Samuels et al., 1993, J. Cell Biol. 121, 909-921). In present study, we used this model system to determine how presence of promotes alterations associated changes in cell shape. Microscopic analysis spreading at early times, revealed retained ability form filopodia; however, they could not lamellipodia, assemble stress fibers, efficiently over culture substrate. Detergent (Triton X-100) studies these major differences morphology organization did result from levels total polymerized cross-linked actin. Biochemical showed cells, addition lacking vinculin, exhibited slightly reduced alpha-actinin paxillin their detergent-insoluble cytoskeleton. The absence correlated a decrease mechanical stiffness integrin-cytoskeleton linkage, as measured using magnetometry. Furthermore, when was replaced by transfection 5.51Vin3 5.51Vin4 cytoskeletal-associated paxillin, efficiency transmembrane coupling, formation actin fibers were all restored near levels. These findings suggest may promote stabilizing focal adhesions transferring stresses drive remodeling, rather than altering level polymerization cross-linking.