Figure 4.

Role of tyrosine phosphorylation and myosin in the modulation of adhesion structures on flexible substrates. Cells were treated with PAO (A–D) or 2,3-butanedione monoxime (E–H) and processed for vinculin (A, B, E, F) or phosphotyrosine (C, D, G, H) immunofluorescence. Treatment of cells with PAO resulted in the formation of large focal adhesions in cells on both soft (0.03% bis-acrylamide; B, D) and rigid (0.26% bis-acrylamide; A, C) substrates. Treatment with 2,3-butanedione monoxime disrupted adhesion structures of cells cultured on substrates with either 0.26% bis-acrylamide (E, G), or 0.03% bis-acrylamide (F, H), and caused vinculin (E, F) and phosphotyrosine (G, H) to localize at small punctate structures regardless of the substrate flexibility. Bar = 10 μm.