Fig. 4: Analysis of integrin β5 interaction with PAK4.

a Cartoon diagram of PAK4-integrin β5 structures superposed on the kinase C-lobes. b Details of integrin β5-PAK4 interaction. Salt bridges indicated by dashed red lines. c Illustration of the pose of Glu767 in the D440N mutant structures (top, bottom) Glu767 coordinates N440, K442, and Ser331. d Surface electrostatics of PAK4 with bound integrin β5 in green. Glu767^β5 is located at the phosphoacceptor residue site. e Close up superposition of the integrin binding site. Residues mutated in panels f–h are indicated. f Pull down of overexpressed GFP-tagged PAK4 catalytic domain with recombinant purified wild-type and mutated integrin β5 tails immobilized on nickel beads. Bound protein was detected by immunoblotting with anti-GFP antibodies. 3% of input lysate is shown in input lane. Tail loading was assessed by Coomassie staining. A representative experiment is shown in the upper panel with the quantification of three independent replicates (normalized to the wild-type β5 tail) shown below. Mean ± s.d. Pull-down of wild-type and mutated PAK4 catalytic domain (g) and full-length PAK4 (h) with wild-type integrin β5 was assessed as in (f). Representative experiments are shown in upper panels and the quantification of multiple independent replicates normalized to the wild-type PAK construct are shown below. Mean ± s.d. (n ≥ 4). Significant difference from wild-type control calculated in one-way ANOVA with Dunnett’s multiple comparison test. Source data are provided as a Source Data file.