Figure 5.

Autolytic fragment of calpain is present in the integrin-containing clusters, which form upstream of Rac activation. BAE cells were transiently transfected with cDNA encoding myc-tagged dominant-negative N17Rac. Cells were detached and replated on fibronectin-coated coverslips for 1 h, fixed, and permeabilized. Transfected cells were detected with anti–myc antibody and autolysed calpain with an antibody that only recognizes the autolysed fragment. Three different transfected cells are shown. Bar, 20 μm.