Figure 6.

Induction of active Cdc42, Rac1, Rho and Ras GTPases by IQGAP3. (A) The relative amount of active small GTPases in 293T-IQGAP3 cells (gray bars) compared to 293T-mock cells (black bars). Total and active forms of GTPases in the cells were quantitated by densitometry after immunoblot analyses. The relative fold changes in this bar graph represent the densitometry values from the representative blots shown in Figure 6B–E. (B) Induction of active Cdc42 by IQGAP3, and association of active Cdc42 with myc-tagged IQGAP3. The total amount of Cdc42 (active + inactive) in the input and active Cdc42 precipitated with GST-Pak1 was analyzed by immunoblot analysis using anti-Cdc42 antibody (upper panel). Interaction between active Cdc42 and myc-tagged IQGAP3 was analyzed by immunoblotting with anti-myc antibody (middle panel). The expression of β-actin served as a quantitative control (lower panel). (C) Induction of active Rac1 by IQGAP3, and association of active Rac1 with myc-tagged IQGAP3. The total amount of Rac1 and active form of Rac1 were analyzed by immunoblotting with anti-Rac1 antibody. (D) Induction of active Rho by IQGAP3, and association of active Rho with myc-tagged IQGAP3. The total amount of Rho and active form of Rho were analyzed by immunoblotting with anti-Rho antibody. (E) Induction of active Ras by IQGAP3, and association of active Ras with myc-tagged IQGAP3. The total amount of Ras and active form of Ras was analyzed by immunoblotting with anti-Ras antibody.