Encyclopedia of Signaling Molecules

2018 Edition
| Editors: Sangdun Choi


  • Andrew C. Hedman
  • David B. SacksEmail author
Reference work entry
DOI: https://doi.org/10.1007/978-3-319-67199-4_101675


 IQGAP1: IQ motif-containing GTPase-activating protein 1; HUMORFA01; SAR1; p195

 IQGAP2: IQ motif-containing GTPase-activating protein 2

 IQGAP3: IQ motif-containing GTPase-activating protein 3

Iqg1/Cyk1 in S. cerevisiae and Rng2 in S. pombe

Historical Background

In 1994, IQGAP1 was identified from a liver cDNA library, and it was named based both on the presence of IQ motifs and a region with sequence similarity to the catalytic domain of Ras GTPase-activating proteins (GAPs) (Weissbach et al. 1994). Early studies revealed that IQGAP1 did not promote GTPase activity but instead stabilizes the GTP bound forms of Cdc42 and Rac1 (Hart et al. 1996). Subsequent investigation has identified an extensive array of proteins, including components of the cytoskeleton, cell surface receptors, and signaling components, that interact with IQGAP1 (Hedman et al. 2015).


The IQGAP family of proteins is found in eukaryotes, including fungi, protists, and vertebrates (Hedman et al. 2015...
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Work in the authors’ laboratory is funded by the Intramural Research Program of the National Institutes of Health.


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Copyright information

© Springer International Publishing AG 2018

Authors and Affiliations

  1. 1.Department of Laboratory MedicineNational Institutes of HealthBethesdaUSA