title: Neural Wiskott-Aldrich syndrome protein (N-WASP)-mediated p120-catenin interaction with Arp2-Actin complex stabilizes endothelial adherens junctions.
abstract: Stable adherens junctions (AJs) are required for formation of restrictive endothelial barrier. Vascular endothelial cadherin from contiguous endothelial cells forms AJs, which are stabilized intracellularly by binding of p120-catenin and cortical actin. Mechanisms inducing cortical actin formation and enabling its linkage with p120-catenin remain enigmatic. We altered the function of neural Wiskott-Aldrich syndrome protein (N-WASP), which induces actin polymerization through actin-related protein 2/3 complex (Arp2/3), to address the role of N-WASP in regulating AJ stability and thereby endothelial permeability. We show that depletion of N-WASP in endothelial cells impaired AJ adhesion and favored the organization of actin from cortical actin to stress fibers, resulting thereby in formation of leaky endothelial barrier. Exposure of the N-WASP-depleted endothelial cell monolayer to the permeability-increasing mediator, thrombin, exaggerated AJ disruption and stress fiber formation, leading to an irreversible increase in endothelial permeability. We show that N-WASP binds p120-catenin through its verprolin cofilin acid (VCA) domain, induces cortical actin formation through Arp2, and links p120-catenin with cortical actin. The interaction of N-WASP with p120-catenin, actin, and Arp2 requires phosphorylation of N-WASP at the Tyr-256 residue by focal adhesion kinase. Expression of the VCA domain of N-WASP or phosphomimicking (Y256D)-N-WASP mutant in endothelial cells stabilizes AJs and facilitates barrier recovery after thrombin stimulation. Our study demonstrates that N-WASP, by mediating p120-catenin interaction with actin-polymerizing machinery, maintains AJs and mitigates disruption of endothelial barrier function by edemagenic agents, therefore representing a novel target for preventing leaky endothelial barrier syndrome.
authors.affiliation: Department of Pharmacology and Center for Lung and Vascular Biology, College of Medicine, University of Illinois, Chicago, Illinois 60612, USA.
authors.forename: Charu
authors.initials: C
authors.lastname: Rajput
authors.forename: Vidisha
authors.initials: V
authors.lastname: Kini
authors.forename: Monica
authors.initials: M
authors.lastname: Smith
authors.forename: Pascal
authors.initials: P
authors.lastname: Yazbeck
authors.forename: Alejandra
authors.initials: A
authors.lastname: Chavez
authors.forename: Tracy
authors.initials: T
authors.lastname: Schmidt
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Nebojsa
authors.initials: N
authors.lastname: Knezevic
authors.forename: Yulia
authors.initials: Y
authors.lastname: Komarova
authors.forename: Dolly
authors.initials: D
authors.lastname: Mehta
mesh_terms: D051377:Actin-Related Protein 2 / Q000235:genetics / Q000378:metabolism*; D051376:Actin-Related Protein 2-3 Complex / Q000235:genetics / Q000378:metabolism; D022005:Adherens Junctions / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D019556:COS Cells; D051177:Catenins / Q000235:genetics / Q000378:metabolism*; D002522:Chlorocebus aethiops; D042783:Endothelial Cells / Q000378:metabolism*; D006801:Humans; D010766:Phosphorylation / Q000235:genetics; D011485:Protein Binding / Q000235:genetics; D017434:Protein Structure, Tertiary; D022502:Stress Fibers / Q000235:genetics / Q000378:metabolism*; D051317:Wiskott-Aldrich Syndrome Protein, Neuronal / Q000235:genetics / Q000378:metabolism*; D000095002:Delta Catenin
chemical_list: C495926:ACTR2 protein, human; D051377:Actin-Related Protein 2; D051376:Actin-Related Protein 2-3 Complex; D051177:Catenins; C495771:WASL protein, human; D051317:Wiskott-Aldrich Syndrome Protein, Neuronal; D000095002:Delta Catenin