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Review
. 2003 Jun;4(6):571-4.
doi: 10.1038/sj.embor.embor867.

IQGAP proteins are integral components of cytoskeletal regulation

Michael W Briggs  1 , David B Sacks
Affiliations
Review

IQGAP proteins are integral components of cytoskeletal regulation

Michael W Briggs et al. EMBO Rep. 2003 Jun.

Abstract

IQGAP1 is a scaffolding protein that binds to a diverse array of signalling and structural molecules. By interacting with its target proteins, human IQGAP1 participates in multiple cellular functions, including Ca(2+)/calmodulin signalling, cytoskeletal architecture, CDC42 and Rac signalling, E-cadherin-mediated cell-cell adhesion and beta-catenin-mediated transcription. Yeast IQGAP homologues are important regulators of cellular morphogenesis because they are required for budding and cytokinesis. Here we discuss the structure and function of IQGAP1 as a member of the family of IQGAP proteins and summarize the current knowledge about IQGAP1 and IQGAP2. Collectively, these data reveal that IQGAP1 is a fundamental regulator of cytoskeletal function.

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Figures

Figure 1
Figure 1
The IQGAP protein family. Diagram of selected IQGAP proteins (adapted from the SMART and Pfam databases). Horizontal red lines denote potential coiled coils and green lines denote stretches of low structural complexity. CHD, calponin homology domain; WW, poly-proline-binding domain; IQ, calmodulin-binding motif; GRD, Ras GTPase-activating protein (GAP)-related domain; RasGAP_C,carboxy-terminal sequence found in members of the IQGAP family.
Figure 2
Figure 2
Schematic diagram depicting the domain structures of human IQGAP1 and IQGAP2. Amino-acid identity and similarity (obtained by a pairwise BLAST comparison) and domain boundaries are indicated. The poly-proline-binding (WW) domains contain residues 679–712 and 594–627 for IQGAP1 and IQGAP2, respectively. Identified binding proteins are listed below their primary binding domains. Proteins in bold have been shown to bind directly to both IQGAP1 and IQGAP2, whereas those in italics are known to interact only with IQGAP1. CaM, calmodulin; ELC, myosin essential light chain; CLIP170, cytoplasmic linker protein 170. Other abbreviations are defined in Fig. 1.
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References

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