TY - JOUR TI - Dlg1 activates beta-catenin signaling to regulate retinal angiogenesis and the blood-retina and blood-brain barriers AU - Cho, Chris AU - Wang, Yanshu AU - Smallwood, Philip M AU - Williams, John AU - Nathans, Jeremy A2 - Gleeson, Joseph G A2 - Stainier, Didier Y VL - 8 PY - 2019 DA - 2019/05/08 SP - e45542 C1 - eLife 2019;8:e45542 DO - 10.7554/eLife.45542 UR - https://doi.org/10.7554/eLife.45542 AB - Beta-catenin (i.e., canonical Wnt) signaling controls CNS angiogenesis and the blood-brain and blood-retina barriers. To explore the role of the Discs large/membrane-associated guanylate kinase (Dlg/MAGUK) family of scaffolding proteins in beta-catenin signaling, we studied vascular endothelial cell (EC)-specific knockout of Dlg1/SAP97. EC-specific loss of Dlg1 produces a retinal vascular phenotype that closely matches the phenotype associated with reduced beta-catenin signaling, synergizes with genetically-directed reductions in beta-catenin signaling components, and can be rescued by stabilizing beta-catenin in ECs. In reporter cells with CRISPR/Cas9-mediated inactivation of Dlg1, transfection of Dlg1 enhances beta-catenin signaling ~4 fold. Surprisingly, Frizzled4, which contains a C-terminal PDZ-binding motif that can bind to Dlg1 PDZ domains, appears to function independently of Dlg1 in vivo. These data expand the repertoire of Dlg/MAGUK family functions to include a role in beta-catenin signaling, and they suggest that proteins other than Frizzled receptors interact with Dlg1 to enhance beta-catenin signaling. KW - vascular endothelial cells KW - canonical Wnt signaling KW - mouse genetics KW - retinal angiogenesis KW - blood-brain barrier KW - blood-retina barrier JF - eLife SN - 2050-084X PB - eLife Sciences Publications, Ltd ER -