Proximity interactome of lymphatic VE-cadherin reveals mechanisms of junctional remodeling and reelin secretion.

In this study, we are the first to use the MiniTurboID generation of the proximity-dependent biotin identification (BioID) technology to illuminate how the lymphatic endothelial cell (LEC) VE-cadherin interactome changes during junctional remodeling in response to the lymphangiocrine factor adrenomedullin. Here, we created a UBC-driven lentiviral expression vector containing the coding sequence for a Ve-Cadehrin-V5-MiniTurboID fusion-protein. After transduction of LECs with Ve-Cadehrin-MiniTurboID lentivirus, we treated these cells with 100 nM adrenomedullin (AM) or vehicle and labeled proximal proteins with 50 µM for 2 hours to capture dynamic changes in the Ve-Cadehrin interactome during AM-induced junctional rearrangement. Biotin-labeled proximity interactors were isolated via streptavidin-affinity purification (AP) and identified using LC-MS/MS mass spectrometry. Our dataset consists of distinct biological replicates consisting of AP enriched proteins from whole cell lysates (WCL, n = 2) or plasma membrane (PM, n = 3) fractions. WCL fractions allow us to capture proximity networks involved in Ve-Cadehrin trafficking and recycling to the PM, while PM fractions allows us to examine membrane-specific changes in AM-induced adherens junctions assembly.