IQGAP1 mediates the second phase of ERK1/2 and AKT phosphorylation in response to pressure overload. (A) Western blot analysis of phosphorylated and total MEK1/2, ERK1/2, and AKT from WT mice subjected to AB for the indicated time. (B) Western blot analysis of phosphorylated and total MEK1/2, ERK1/2, and AKT from WT and IQGAP1-null mice subjected to 10 min of AB. (C) Quantification of western blot bands, expressed as phospho/total protein ratio (n = 6 hearts/group). (D) Western blot analysis of phosphorylated and total MEK1/2, ERK1/2, and AKT in WT and IQGAP1−/− hearts subjected to AB for the indicated time. Vinculin was used as a loading control. (E) Quantification of western blot bands expressed as phospho/total protein ratio (n = 4 hearts/group). *P < 0.05 vs. sham; °P < 0.05 vs. WT.