S-Nitrosation of β-Catenin and p120 Catenin

Rationale:Endothelial adherens junction proteins constitute an important element in the control of microvascular permeability. Platelet-activating factor (PAF) increases permeability to macromolecules via translocation of endothelial nitric oxide synthase (eNOS) to cytosol and stimulation of eNOS-derived nitric oxide signaling cascade. The mechanisms by which nitric oxide signaling regulates permeability at adherens junctions are still incompletely understood. Objective:We explored the hypothesis that PAF stimulates hyperpermeability via S-nitrosation (SNO) of adherens junction proteins. Methods and Results:We measured PAF-stimulated SNO of β-catenin and p120-catenin (p120) in 3 cell lines: ECV-eNOSGFP, EAhy926 (derived from human umbilical vein), and postcapillary venular endothelial cells (derived from bovine heart endothelium) and in the mouse cremaster muscle in vivo. SNO correlated with diminished abundance of β-catenin and p120 at the adherens junction and with hyperpermeability. Tumor necrosis fact...