IQ Motif Containing GTPase Activating Protein 1 (IQGAP1)

Ras GTPase-activating-like protein IQGAP1 is a member of the IQGAP family. The protein contains four IQ domains, one calponin homology domain, one Ras-GAP domain and one WW domain. It interacts with components of the cytoskeleton, with cell adhesion molecules, and with several signaling molecules to regulate cell morphology and motility. Expression of the protein is upregulated by gene amplification in two gastric cancer cell lines.The IQGAP1 cDNA encodes a 1,657-amino acid polypeptide with significant similarity to the Ras-related GTPase-activating (RasGAP) family of proteins. The N-terminal domain contains 6 copies of a unique motif and 4 IQ motifs (named for the presence of tandem isoleucine and glutamine residues), which are known to modulate binding with calmodulin .