PT  - JOURNAL ARTICLE
AU  - Amelia M Webb
AU  - Caitlin R Francis
AU  - Jayson M Webb
AU  - Hayle Kincross
AU  - Keanna M Lundy
AU  - Rachael Judson
AU  - Dawn Westhoff
AU  - Stryder M Meadows
AU  - Erich J Kushner
TI  - EHBP1 and EHD2 regulate Dll4 caveolin-mediated endocytosis during blood vessel development
AID  - 10.1101/2020.05.19.104547
DP  - 2020 Jan 01
TA  - bioRxiv
PG  - 2020.05.19.104547
4099  - http://biorxiv.org/content/early/2020/05/20/2020.05.19.104547.short
4100  - http://biorxiv.org/content/early/2020/05/20/2020.05.19.104547.full
AB  - 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 in vitro and in vivo. 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.Competing Interest StatementThe authors have declared no competing interest.