Peer-Reviewed Journal Details
Mandatory Fields
Dwane, S,Durack, E,O'Connor, R,Kiely, PA
2014
January
Cellular Signalling
RACK1 promotes neurite outgrowth by scaffolding AGAP2 to FAK
Validated
WOS: 24 ()
Optional Fields
RACK1 FAK IGF-IR AGAP2 Cell migration FOCAL ADHESION KINASE INTEGRIN-MEDIATED ADHESION GTPASE-ACTIVATING PROTEIN CELL-MIGRATION TYROSINE KINASE NERVOUS-SYSTEM GROWTH CONE PKC-DELTA BETA-1-INTEGRIN LOCALIZATION
26
9
18
RACK1 binds proteins in a constitutive or transient manner and supports signal transmission by engaging in diverse and distinct signalling pathways. The emerging theme is that RACK1 functions as a signalling switch, recruiting proteins to form distinct molecular complexes. In focal adhesions, RACK1 is required for the regulation of FAK activity and for integrating a wide array of cellular signalling events including the integration of growth factor and adhesion signalling pathways. FAK is required for cell adhesion and migration and has a well-established role in neurite outgrowth and in the developing nervous system. However, the mechanism by which FAK activity is regulated in neurons remains unknown. Using neuronal cell lines, we determined that differentiation of these cells promotes an interaction between the scaffolding protein RACK1 and FAK. Disruption of the RACK1/FAK interaction leads to decreased neurite outgrowth suggesting a role for the interaction in neurite extension. We hypothesised that RACK1 recruits proteins to FAK, to regulate FAK activity in neuronal cells. To address this, we immunoprecipitated RACK1 from rat hippocampus and searched for interacting proteins by mass spectrometry. We identified AGAP2 as a novel RACK1-interacting protein. Having confirmed the RACK1-AGAP2 interaction biochemically, we show RACK1-AGAP2 to localise together in the growth cone of differentiated cells, and confirm that these proteins are in complex with FAK. This complex is disrupted when RACK1 expression is suppressed using siRNA or when mutants of RACK1 that do not interact with FAK are expressed in cells. Similarly, suppression of AGAP2 using siRNA leads to increased phosphorylation of FAK and increased cell adhesion resulting in decreased neurite outgrowth. Our results suggest that RACK1 scaffolds AGAP2 to FAK to regulate FAK activity and cell adhesion during the differentiation process. (C) 2013 Elsevier Inc. All rights reserved.
10.1016/j.cellsig.2013.08.036
Grant Details