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Paxillin mediates stretch‐induced Rho signaling and endothelial permeability via assembly of paxillin‐p42/44MAPK‐GEF‐H1 complex
Author(s) -
Gawlak Grzegorz,
Tian Yufeng,
O'Donnell James J.,
Tian Xinyong,
Birukova Anna A.,
Birukov Konstantin G.
Publication year - 2014
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fj.13-245142
Subject(s) - paxillin , microbiology and biotechnology , mapk/erk pathway , phosphorylation , guanine nucleotide exchange factor , focal adhesion , mechanotransduction , chemistry , gtpase , biology
Suboptimal ventilator support or regional ventilation heterogeneity in inflamed lungs causes excessive tissue distension, which triggers stretch‐induced pathological signaling and may lead to vascular leak and lung dysfunction. Focal adhesions (FAs) are cell‐substrate adhesive complexes participating in cellular mechanotransduction and regulation of the Rho GTPase pathway. Stretch‐induced Rho regulation remains poorly understood. We used human lung endothelial cells (ECs) exposed to pathological cyclic stretch (CS) at 18% distension to test the hypothesis that FA protein paxillin participates in CS‐induced Rho activation by recruiting the Rho‐specific guanine nucleotide exchange factor GEF‐H1. CS induced phosphorylation of paxillin and activated p42/44‐MAP kinase, Rho GTPase, and paxillin/GEF‐H1/p42/44‐MAPK association. CS caused nearly 2‐fold increase in EC permeability, which was attenuated by paxillin knockdown. Expression of the paxillin‐Y31/118F phosphorylation mutant decreased the CS‐induced paxillin/GEF‐H1 association (16.3±4.1%), GEF‐H1 activation (28.9±9.2%), and EC permeability (28.7±8.1%) but not CS‐induced p42/44‐MAPK activation. Inhibition of p42/44‐MAPK suppressed CS‐induced paxillin/GEF‐H1 interactions (15.9±7.9%), GEF‐H1 activation (11.7±4.3%), and disruption of EC monolayer. Expression of GEF‐H1T678A lacking p42/44‐MAPK phosphorylation site attenuated Rho activation (31.2±11.6%). We conclude that MAPK‐dependent targeting of GEF‐H1 to paxillin is involved in the regulation of CS‐induced Rho signaling and EC permeability. This study proposes a novel concept of paxillin‐GEF‐H1‐p42/44‐MAPK module as a regulator of pathological mechanotransduction.—Gawlak, G., Tian, Y., O'Donnell, J. J., III, Tian, X., Birukova, A. A., Birukov, K. G. Paxillin mediates stretch‐induced Rho signaling and endothelial permeability via assembly of paxillin‐p42/44MAPK‐GEF‐H1 complex. FASEB J . 28, 3249–3260 (2014). www.fasebj.org