Fig. 8. Activation of Cdc42 and its association with downstream targets during EC tube morphogenesis in 3D collagen matrices. ECs were treated with S-GFP-Cdc42 or control GFP-Cdc42 recombinant adenovirus (Ad) before suspension in 3D collagen matrices. Extracts at the indicated time-points were prepared. Equal amounts of extracts were incubated with S-protein agarose beads and probed with antibodies to phospho-Pak2, phospho-Pak4 and Par3 to detect binding interactions.