FIG. 4.

Motility of SFK-null fibroblasts expressing variants of cSrc. (A, B, D, and E) Directed cell migration of SYF cells (A) and cells reexpressing full-length Src (D), as well as mutants with an Arg→Leu mutation at residue 175 in the SH2 domain (R175L) (B), and the R175L construct targeted to FAs (R175L-FAT) (D). A confluent monolayer was wounded, and cells were fixed at 0, 6, and 10 h after injury and imaged by phase-contrast microscopy. (C and F) Random motility of R175L cells (C) and R175L-FAT cells (F) on fibronectin over 4.5 h. Cells were sparsely plated onto fibronectin-coated dishes and allowed to spread for 1 h, and nuclear positions were tracked from images captured every 10 min. Both the x and y axes show distances in micrometers. The motility of SYF cells remained defective after reexpression of a Src construct with an R175L mutation in the SH2 domain, but migration was restored after targeting the construct to FAs.