Figure 2

Paxillin S273 phosphorylation, PAK1 kinase activity, βPIX GEF activity, βPIX binding to PAK1 and phosphatase activity regulate adhesion dynamics. (A) Adhesion assembly rates (left) and disassembly rates (right) for cells expressing paxillin-WT, -S273A, -S273D (blue), co-expression of paxillin-WT and PAK1-WT, -KD, -CA (red), co-expression of paxillin-WT and βPIX-WT, -ΔSH3, -LL variants (green), and cells with paxillin-WT treated with 10 μM IPA-3 or 50 nM okadaic acid (grey). (B) Average adhesion size (left) and average adhesion stability time (right) for cells expressing paxillin variants (blue), co-expressing paxillin and PAK1 variants (red), and co-expressing paxillin-WT and βPIX variants (green). (C) Time series of cells expressing paxillin-S273D (left panel) and -S273A (right panel). Cyan arrowhead indicates protrusive edges, orange arrowhead indicates retractive edges. Scale bars are 5 μm. (D) Adhesion assembly rates at protrusive (cyan bars) or retractive (orange bars) edges of the cell. Error bars represent SEM. Two stars (**) corresponds to p < 0.001, three stars ***p < 0.0001. n = 45–60 adhesions. n = 15–20 adhesions, N = 3–5 cells per experiment and 3 independent experiments.