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Structural basis for activation of trimeric Gi proteins by multiple growth factor receptors via GIV/Girdin

A long-standing issue in the field of signal transduction is to understand the cross-talk between receptor tyrosine kinases (RTKs) and heterotrimeric G proteins, two major and distinct signaling hubs that control eukaryotic cell behavior. Although stimulation of many RTKs leads to activation of trim...

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Autores principales: Lin, Changsheng, Ear, Jason, Midde, Krishna, Lopez-Sanchez, Inmaculada, Aznar, Nicolas, Garcia-Marcos, Mikel, Kufareva, Irina, Abagyan, Ruben, Ghosh, Pradipta
Formato: Online Artículo Texto
Lenguaje:English
Publicado: The American Society for Cell Biology 2014
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4230624/
https://www.ncbi.nlm.nih.gov/pubmed/25187647
http://dx.doi.org/10.1091/mbc.E14-05-0978
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author Lin, Changsheng
Ear, Jason
Midde, Krishna
Lopez-Sanchez, Inmaculada
Aznar, Nicolas
Garcia-Marcos, Mikel
Kufareva, Irina
Abagyan, Ruben
Ghosh, Pradipta
author_facet Lin, Changsheng
Ear, Jason
Midde, Krishna
Lopez-Sanchez, Inmaculada
Aznar, Nicolas
Garcia-Marcos, Mikel
Kufareva, Irina
Abagyan, Ruben
Ghosh, Pradipta
author_sort Lin, Changsheng
collection PubMed
description A long-standing issue in the field of signal transduction is to understand the cross-talk between receptor tyrosine kinases (RTKs) and heterotrimeric G proteins, two major and distinct signaling hubs that control eukaryotic cell behavior. Although stimulation of many RTKs leads to activation of trimeric G proteins, the molecular mechanisms behind this phenomenon remain elusive. We discovered a unifying mechanism that allows GIV/Girdin, a bona fide metastasis-related protein and a guanine-nucleotide exchange factor (GEF) for Gαi, to serve as a direct platform for multiple RTKs to activate Gαi proteins. Using a combination of homology modeling, protein–protein interaction, and kinase assays, we demonstrate that a stretch of ∼110 amino acids within GIV C-terminus displays structural plasticity that allows folding into a SH2-like domain in the presence of phosphotyrosine ligands. Using protein–protein interaction assays, we demonstrated that both SH2 and GEF domains of GIV are required for the formation of a ligand-activated ternary complex between GIV, Gαi, and growth factor receptors and for activation of Gαi after growth factor stimulation. Expression of a SH2-deficient GIV mutant (Arg 1745→Leu) that cannot bind RTKs impaired all previously demonstrated functions of GIV—Akt enhancement, actin remodeling, and cell migration. The mechanistic and structural insights gained here shed light on the long-standing questions surrounding RTK/G protein cross-talk, set a novel paradigm, and characterize a unique pharmacological target for uncoupling GIV-dependent signaling downstream of multiple oncogenic RTKs.
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spelling pubmed-42306242015-01-20 Structural basis for activation of trimeric Gi proteins by multiple growth factor receptors via GIV/Girdin Lin, Changsheng Ear, Jason Midde, Krishna Lopez-Sanchez, Inmaculada Aznar, Nicolas Garcia-Marcos, Mikel Kufareva, Irina Abagyan, Ruben Ghosh, Pradipta Mol Biol Cell Articles A long-standing issue in the field of signal transduction is to understand the cross-talk between receptor tyrosine kinases (RTKs) and heterotrimeric G proteins, two major and distinct signaling hubs that control eukaryotic cell behavior. Although stimulation of many RTKs leads to activation of trimeric G proteins, the molecular mechanisms behind this phenomenon remain elusive. We discovered a unifying mechanism that allows GIV/Girdin, a bona fide metastasis-related protein and a guanine-nucleotide exchange factor (GEF) for Gαi, to serve as a direct platform for multiple RTKs to activate Gαi proteins. Using a combination of homology modeling, protein–protein interaction, and kinase assays, we demonstrate that a stretch of ∼110 amino acids within GIV C-terminus displays structural plasticity that allows folding into a SH2-like domain in the presence of phosphotyrosine ligands. Using protein–protein interaction assays, we demonstrated that both SH2 and GEF domains of GIV are required for the formation of a ligand-activated ternary complex between GIV, Gαi, and growth factor receptors and for activation of Gαi after growth factor stimulation. Expression of a SH2-deficient GIV mutant (Arg 1745→Leu) that cannot bind RTKs impaired all previously demonstrated functions of GIV—Akt enhancement, actin remodeling, and cell migration. The mechanistic and structural insights gained here shed light on the long-standing questions surrounding RTK/G protein cross-talk, set a novel paradigm, and characterize a unique pharmacological target for uncoupling GIV-dependent signaling downstream of multiple oncogenic RTKs. The American Society for Cell Biology 2014-11-05 /pmc/articles/PMC4230624/ /pubmed/25187647 http://dx.doi.org/10.1091/mbc.E14-05-0978 Text en © 2014 Lin, Ear, et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0). “ASCB®,” “The American Society for Cell Biology®,” and “Molecular Biology of the Cell®” are registered trademarks of The American Society for Cell Biology.
spellingShingle Articles
Lin, Changsheng
Ear, Jason
Midde, Krishna
Lopez-Sanchez, Inmaculada
Aznar, Nicolas
Garcia-Marcos, Mikel
Kufareva, Irina
Abagyan, Ruben
Ghosh, Pradipta
Structural basis for activation of trimeric Gi proteins by multiple growth factor receptors via GIV/Girdin
title Structural basis for activation of trimeric Gi proteins by multiple growth factor receptors via GIV/Girdin
title_full Structural basis for activation of trimeric Gi proteins by multiple growth factor receptors via GIV/Girdin
title_fullStr Structural basis for activation of trimeric Gi proteins by multiple growth factor receptors via GIV/Girdin
title_full_unstemmed Structural basis for activation of trimeric Gi proteins by multiple growth factor receptors via GIV/Girdin
title_short Structural basis for activation of trimeric Gi proteins by multiple growth factor receptors via GIV/Girdin
title_sort structural basis for activation of trimeric gi proteins by multiple growth factor receptors via giv/girdin
topic Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4230624/
https://www.ncbi.nlm.nih.gov/pubmed/25187647
http://dx.doi.org/10.1091/mbc.E14-05-0978
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