Figure 1.

Upstream regulators of IQGAP proteins. Various plasma membrane receptors such as G-protein-coupled receptors (GPCRs), receptor tyrosine kinases (RTKs) and integrins signal towards IQGAP (green) proteins through direct interaction or the activation of small GTPases and protein kinase C (PKC). IQGAP becomes activated through phosphorylation and conformational changes at its carboxyl terminus. CHD, calponin homology domain; CR3, complement receptor 3; DBR, diaphanous binding region; EGF, epidermal growth factor; FGF, fibroblast growth factor; GRD, Gap related domain; IQGAPs, proteins containing calmodulin-binding IQ motifs and with homology to GTPase activating proteins (GAPs); NGF, nerve growth factor; VEGF, vascular endothelial growth factor; WW, domain with two conserved Trp (W) residues.