Reference - Detail
|Author||Hirano M, Hirano K.|
|Title||Myosin di-phosphorylation and peripheral actin bundle formation as initial events during endothelial barrier disruption.|
The phosphorylation of the 20-kD myosin light chain (MLC) and actin filament formation play a key role in endothelial barrier disruption. MLC is either mono- or di-phosphorylated (pMLC and ppMLC) at T18 or S19. The present study investigated whether there are any distinct roles of pMLC and ppMLC in barrier disruption induced by thrombin. Thrombin induced a modest bi-phasic increase in pMLC and a robust mono-phasic increase in ppMLC. pMLC localized in the perinuclear cytoplasm during the initial phase, while ppMLC localized in the cell periphery, where actin bundles were formed. Later, the actin bundles were rearranged into stress fibers, where pMLC co-localized. Rho-kinase inhibitors inhibited thrombin-induced barrier disruption and peripheral localization of ppMLC and actin bundles. The double, but not single, mutation of phosphorylation sites abolished the formation of peripheral actin bundles and the barrier disruption, indicating that mono-phosphorylation of MLC at either T18 or S19 is functionally sufficient for barrier disruption. Namely, the peripheral localization, but not the degree of phosphorylation, is suggested to be essential for the functional effect of ppMLC. These results suggest that MLC phosphorylation and actin bundle formation in cell periphery are initial events during barrier disruption.
|MeSH||Actins / genetics Actins / metabolism Animals Aorta / cytology Aorta / drug effects Aorta / metabolism Calcium / metabolism Capillary Permeability / drug effects* Electric Impedance Endothelial Cells / cytology Endothelial Cells / drug effects* Endothelial Cells / metabolism Endothelium, Vascular / cytology Endothelium, Vascular / drug effects Endothelium, Vascular / metabolism Gene Expression Regulation Heterocyclic Compounds, 4 or More Rings / pharmacology Mutation Myosin Light Chains / genetics Myosin Light Chains / metabolism* Myosins / antagonists & inhibitors Myosins / genetics Myosins / metabolism Phosphorylation / drug effects* Primary Cell Culture Protein Kinase Inhibitors / pharmacology Receptor, PAR-1 / genetics Receptor, PAR-1 / metabolism Serine / metabolism Swine Threonine / metabolism Thrombin / pharmacology* rho-Associated Kinases / antagonists & inhibitors rho-Associated Kinases / genetics rho-Associated Kinases / metabolism|
|WOS Category||BIOCHEMISTRY & MOLECULAR BIOLOGY|
|DNA material||human MLC20 WT (RDB14158) human MLC20 T18A (RDB14159) human MLC20 S19A (RDB14160) human MLC20 T18A+S19A (RDB14161).|