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Identification of an IQGAP1/AKAP79 complex in β‐cells
Author(s) -
Nauert J. Brian,
Rigas Johanna D.,
Lester Linda B.
Publication year - 2003
Publication title -
journal of cellular biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.028
H-Index - 165
eISSN - 1097-4644
pISSN - 0730-2312
DOI - 10.1002/jcb.10604
Subject(s) - iqgap1 , scaffold protein , microbiology and biotechnology , protein kinase a , calmodulin , chemistry , immunoprecipitation , gtp' , guanine nucleotide exchange factor , biochemistry , gtpase , biology , kinase , signal transduction , enzyme , gene
Abstract IQGAP1, is a recently discovered scaffold protein proposed to regulate membrane cytoskeleton events through protein–protein interactions with F‐actin, E‐cadherin, β‐catenin, and CLIP170. The binding of IQGAP1 to its partners is regulated by calcium/calmodulin (Ca ++ /CaM) and the small molecular weight guanine nucleotide triphosphatases (GTPases), Cdc42, and Rac1. Here we identify a novel IQGAP1 scaffolding function by isolating the cyclic AMP dependent kinase (PKA) with IQGAP1. IQGAP1 was co‐purified with PKA using 5′‐cyclic AMP (cAMP) affinity chromatography and PKA activity was co‐immunoprecipitated with IQGAP1 using an anti‐IQGAP1 antibody. The association of IQGAP1 with PKA was shown to occur through a direct interaction between A kinase anchoring protein 79 (AKAP79) and the carboxyl‐terminal domain of IQGAP1. This suggests that cAMP/PKA may be coupled with Ca ++ /CaM and GTPases through an IQGAP1/AKAP79 complex. J. Cell. Biochem. 90: 97–108, 2003. © 2003 Wiley‐Liss, Inc.