An EMMPRIN/γ-catenin/Nm23 complex drives ATP production and actomyosin contractility at endothelial junctions

Abstract

Cell-cell adhesions are important sites through which cells experience and resist forces. In endothelial cells, these forces regulate junction dynamics and determine endothelial barrier fitness. We identify the Ig superfamily member EMMPRIN as a coordinator of forces at endothelial junctions. EMMPRIN location at junctions correlates with endothelial junction strength at different mouse vascular beds. Accordingly, EMMPRIN-deficient mice show altered junctions and increased permeability. Lack of EMMPRIN alters VE-cadherin pattern and function by decreasing actomyosin contractility and tugging forces at endothelial cell junctions. EMMPRIN ensures proper actomyosin-driven maturation of competent endothelial junctions by forming a molecular complex with γ-catenin and Nm23, a nucleoside diphosphate kinase, thereby locally fueling ATP to the actomyosin machinery. These results provide a novel mechanism for regulation of actomyosin contractility at endothelial junctions and might have broader implications in biological contexts such as angiogenesis, collective migration and tissue morphogenesis by coupling compartmentalized energy production to junction assembly.