EHBP1 and EHD2 regulate Dll4 caveolin-mediated endocytosis during blood vessel development

Despite the centrality of Delta/Notch signaling to activate lateral inhibition and define tip/stalk cell specification during angiogenesis, many mechanisms are still incompletely understood. Here, we report that the proteins Epsin homology domain protein 2 (EHD2) and EHD2 binding partner 1 (EHBP1) are required for proper angiogenic signaling in endothelial cells (ECs). EHBP1 and EHD2 localize to Delta-like ligand 4 (Dll4) and actin at adherens junctions. Importantly, we demonstrate that Dll4 is internalized via caveolin-dependent endocytosis, which is reliant on both EHBP1 and EHD2. In the absence of EHBP1 and EHD2, Dll4 endocytosis is significantly impaired, leading to blood vessel defects both and . We propose a model wherein EHBP1 and EHD2 regulate Dll4 endocytosis by anchoring its caveolar endocytic pit to the actin cytoskeleton. Overall, this provides mechanistic detail of how Dll4 is endocytosed during Notch activation.