Role of CaM kinase II and ERK activation in thrombin-induced endothelial cell barrier dysfunction

Talaibek Borbiev, Alexander Dmitriyevich Verin, Anna Birukova, Feng Liu, Michael T. Crow, Joe G.N. Garcia

Research output: Contribution to journalArticlepeer-review

81 Scopus citations


We have previously shown that thrombin-induced endothelial cell barrier dysfunction involves cytoskeletal rearrangement and contraction, and we have elucidated the important role of endothelial cell myosin light chain kinase and the actin- and myosin-binding protein caldesmon. We evaluated the contribution of calmodulin (CaM) kinase II and extracellular signal-regulated kinase (ERK) activation in thrombin-mediated bovine pulmonary artery endothelial cell contraction and barrier dysfunction. Similar to thrombin, infection with a constitutively active adenoviral a-CaM kinase II construct induced significant ERK activation, indicating that CaM kinase II activation lies upstream of ERK. Thrombin-induced ERK-dependent caldesmon phosphorylation (Ser789) was inhibited by either KN-93, a specific CaM kinase II inhibitor, or U0126, an inhibitor of MEK activation. Immunofluorescence microscopy studies revealed phosphocaldesmon colocalization within thrombin-induced actin stress fibers. Pretreatment with either U0126 or KN-93 attenuated thrombin-mediated cytoskeletal rearrangement and evoked declines in transendothelial electrical resistance while reversing thrombin-induced dissociation of myosin from nondenaturing caldesmon immunoprecipitates. These results strongly suggest the involvement of CaM kinase II and ERK activities in thrombin-mediated caldesmon phosphorylation and both contractile and barrier regulation.

Original languageEnglish (US)
Pages (from-to)L43-L54
JournalAmerican Journal of Physiology - Lung Cellular and Molecular Physiology
Issue number1 29-1
StatePublished - Jul 1 2003
Externally publishedYes


  • Caldesmon
  • Extracellular signal-regulated kinase
  • Thrombin
  • Transendothelial electrical resistance

ASJC Scopus subject areas

  • Physiology
  • Pulmonary and Respiratory Medicine
  • Physiology (medical)
  • Cell Biology


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