Figure 5.

Membrane receptor signalling activates the IQGAP1-mediated pathway. (a,b) Immunoblotting after replating on fibronectin (FN) or COL for 30 min in MDA-MB-231 cells transfected with siRNAs against the indicated proteins (a), mean ± s.d. of n = 3 independent experiments (b). P = 0.82, 0.011, 0.95 (FN), 0.0036, 0.0001, 0.88 (COL). (c–e) Immunoblotting after treating with the indicated agonists (10 ng ml⁻¹ EGF, 30 ng ml⁻¹ PDGF, 20 ng ml⁻¹ IGF-1, 15 µM LPA, or 30 ng ml⁻¹SDF-1α) for 15 min in MDA-MB-231 cells transfected with siRNAs against control, IQGAP1 or PIPKIα (c,d), mean ± s.d. of n = 3 independent experiments (e). P = 0.011, 0.001 (S. free), 0.012, 0.001 (EGF), 0.0069, 0.001 (PDGF), 0.021, 0.001 (IGF-1), 0.0042, 0.009 (LPA), 0.001, 0.001 (SDF-1α). (f,g) Interactions of the p110α subunit of PI(3)K with IQGAP1 and PIPKIα were analysed by immunoprecipitation in Hs578T cells expressing shRNAs against the indicated proteins (f), mean ± s.d. of n = 3 independent experiments (g). P = 0.001, 0.001, 0.011, 0.001, 0.042, 0.020, 0.026, 0.020, 0.016, 0.001, 0.001, 0.012. Paired Student’s t-tests were used for statistical analysis (*, P < 0.05; **, P < 0.01; NS, not significant). Source data for b,e,g can be found in Supplementary Table 1. Unprocessed original scans of blots are shown in Supplementary Fig. 7.