FIGURE 8.
FGD2 activates Cdc42. A, the “specificity patch” within the DH domains of RhoGEFs specific for Cdc42 (ASEF, PEM2, intersectin, and FGD1,3,4) are aligned with the corresponding FGD2 sequence. The conserved leucine mediating effective binding to Cdc42 is shaded in gray. B, lysates from COS-7 cells transfected with Myc-Cdc42 and EGFP, EGFP-tagged FGD2, FGD2-DHPH domain (DHPH), or FGD2FYVEKT mutant (FYVEKT) were immunoprecipitated with ACK1-crib-GST beads. Immunoprecipitated beads (IP; Ack, upper panels) or whole cell lysates (WCL; lower panels) were electrophoresed and immunoblotted with anti-Myc (right panels) or anti-EGFP (left panels). Lysates from transfected COS-7 cells expressing dominant active (Cdc42DA+) and negative (Cdc42DN–) EGFP-tagged Cdc42 mutants were used as controls (left panels). This experiment was performed three times with reproducible results.