Modulation of FAK and Src adhesion signaling occurs independently of adhesion complex composition

ER Horton, JD Humphries, B Stutchbury… - Journal of Cell …, 2016 - rupress.org
ER Horton, JD Humphries, B Stutchbury, G Jacquemet, C Ballestrem, ST Barry…
Journal of Cell Biology, 2016rupress.org
Integrin adhesion complexes (IACs) form mechanochemical connections between the
extracellular matrix and actin cytoskeleton and mediate phenotypic responses via
posttranslational modifications. Here, we investigate the modularity and robustness of the
IAC network to pharmacological perturbation of the key IAC signaling components focal
adhesion kinase (FAK) and Src. FAK inhibition using AZ13256675 blocked FAKY397
phosphorylation but did not alter IAC composition, as reported by mass spectrometry. IAC …
Integrin adhesion complexes (IACs) form mechanochemical connections between the extracellular matrix and actin cytoskeleton and mediate phenotypic responses via posttranslational modifications. Here, we investigate the modularity and robustness of the IAC network to pharmacological perturbation of the key IAC signaling components focal adhesion kinase (FAK) and Src. FAK inhibition using AZ13256675 blocked FAKY397 phosphorylation but did not alter IAC composition, as reported by mass spectrometry. IAC composition was also insensitive to Src inhibition using AZD0530 alone or in combination with FAK inhibition. In contrast, kinase inhibition substantially reduced phosphorylation within IACs, cell migration and proliferation. Furthermore using fluorescence recovery after photobleaching, we found that FAK inhibition increased the exchange rate of a phosphotyrosine (pY) reporter (dSH2) at IACs. These data demonstrate that kinase-dependent signal propagation through IACs is independent of gross changes in IAC composition. Together, these findings demonstrate a general separation between the composition of IACs and their ability to relay pY-dependent signals.
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