Figure 6.

Phosphoinositide binding regulates IQGAP1 function in actin polymerization. (A) Control or PIPKIγ knockdown MDA-MB-231 cells were grown on cover glass for 24 h. Cells were fixed and endogenous IQGAP1 and F-actin were stained. Cells were photographed at × 600 magnification. (B) A total of 0.05 μM of His–C2 WT or AA3 mutant was incubated with 1 μM of GST–C1 immobilized on glutathione beads in the absence or presence of the indicated phosphoinositide liposomes (2 μM) for 10 min. Liposome-bound proteins were detected by immunoblotting with an anti-His antibody. Immunoblots were quantified and the graph is shown as mean±s.d. of three independent experiments. (C) Actin polymerization in the presence of the indicated combinations of GST–IQGAP1-C (50 nM) or 5% PI4,5P₂ liposomes (2 μM). The experiments described above were performed independently at least four times.

Source data for this figure is available on the online supplementary information page.

Source Data for Figure 6 ^{(246KB, pdf)}