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Involvement of myosin light-chain kinase in endothelial cell retraction

Journal Article · · Proceedings of the National Academy of Sciences of the United States of America; (USA)
DOI:https://doi.org/10.1073/pnas.87.1.16· OSTI ID:6968819
;  [1]
  1. Saint Louis Univ. School of Medicine, MO (USA)
Permeabilized bovine pulmonary artery endothelial cell monolayers were used to investigate the mechanism of endothelial cell retraction. Postconfluent endothelial cells permeabilized with saponin retracted upon exposure to ATP and Ca{sup 2+}. Retraction was accompanied by thiophosphorylation of 19,000-Da myosin light chains when adenosine 5'-(gamma-({sup 35}S)thio)triphosphate was included in the medium. Both retraction and thiophosphorylation of myosin light chains exhibited a graded quantitative dependence on Ca{sup 2+}. When permeabilized monolayers were extracted in buffer D containing 100 mM KCl and 30 mM MgCl2 for 30 min, the cells failed to retract upon exposure to ATP and Ca{sup 2+}, and no thiophosphorylation of myosin light chains occurred. The ability both to retract and to thiophosphorylate myosin light chains was restored by the addition to the permeabilized, extracted cells of myosin light-chain kinase and calmodulin together but not by either alone. These studies indicate that endothelial cell retraction, as does smooth muscle contraction, depends on myosin light-chain kinase phosphorylation of myosin light chains.
OSTI ID:
6968819
Journal Information:
Proceedings of the National Academy of Sciences of the United States of America; (USA), Journal Name: Proceedings of the National Academy of Sciences of the United States of America; (USA) Vol. 87:1; ISSN PNASA; ISSN 0027-8424
Country of Publication:
United States
Language:
English