Fig. 7: The P-Rex1/Rac1 axis plays essential roles in cellular functions regulated by NRBP1.

A Western blotting validation of NRBP1 knockdown, NRBP1 rescue and P-Rex1 knockdown. MDA-MB-231 cells with shRNA-mediated NRBP1 knockdown were complemented with expression of shRNA-resistant NRBP1 in the presence or absence of P-Rex1 knockdown. Parental cells+/− P-Rex1 knockdown were also included as controls. Total cell lysates or P-Rex1 IPs were Western blotted as indicated. B Rescue of cell migration by NRBP1 is P-Rex1 dependent. Cells validated in (A) were subjected to transwell assays. C Expression of Rac1_G12V. MDA-MB-231 cells with shRNA-mediated NRBP1 knockdown were programmed to express GFP-Rac1_G12V. Cell lysates were Western blotted as indicated. D Effect of active Rac1 on monolayer proliferation of NRBP1-depleted cells. Cells validated in (C) were subjected to MTS assays. Data were obtained at Day 4. E Effect of active Rac1 on invasion of NRBP1-depleted cells. Cells validated in (C) were subjected to transwell assays. For B, D and E, error bars represent the standard error of the mean from n = 3 independent experiments. NS indicates p > 0.05, *p < 0.05, **p < 0.01, ***p < 0.001 by two-way ANOVA with Tukey’s multiple comparisons test.