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ERM phosphorylation is involved in 2‐methoxyestradiol‐induced endothelial hyperpermeability
Author(s) -
Bogatcheva Natalia V,
Zemskova Marina A,
Gorshkov Boris A,
Poirier Christophe,
Kim Kiung Mi,
Verin Alexander D
Publication year - 2011
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/fasebj.25.1_supplement.1101.7
Subject(s) - moesin , phosphorylation , microbiology and biotechnology , ezrin , protein kinase c , radixin , cytoskeleton , p38 mitogen activated protein kinases , kinase , chemistry , stress fiber , biology , protein kinase a , biochemistry , cell , focal adhesion
We have shown earlier that microtubule disruptor 2‐methoxyestradiol (2ME) induces endothelial barrier dysfunction via an activation of p38 and Rho kinases and the rearrangement of actin cytoskeleton. Using protein kinase C (PKC) inhibitors Ro‐31‐7549 and Ro‐32‐0432, we show here that 2ME‐induced barrier dysfunction is also PKC‐dependent. This study tests the hypotheses that known PKC substrates ezrin, radixin, and moesin (ERM) are phosphorylated in response to 2ME, and this phosphorylation is important for barrier dysfunction. We show that ERM are phosphorylated in both PKC‐ and p38‐dependent manner, and phosphorylation changes intracellular localization of ERM. Using siRNA approach, we next show that ERM play role in 2ME‐induced hyperpermeability and actin rearrangement. Cells over‐expressing phosphorylation‐deficient form of the major endothelial ERM, moesin, manifest impaired stress fiber formation in response to 2ME. Cells depleted for ERM proteins and cells over‐expressing phosphorylation‐deficient ERM mutants exhibit lesser attenuation of 2ME‐induced barrier disruption in the presence of PKC inhibitor Ro‐31‐7549. These results suggest a critical role of PKC activation in response to microtubule‐disrupting agents and implicate ERM phosphorylation in the barrier dysfunction induced by 2ME. This work was supported by AHA SDG 0930038N and NHLBI grants HL‐80675, HL‐083327, HL‐067307.