TY - JOUR TI - Heart of glass anchors Rasip1 at endothelial cell-cell junctions to support vascular integrity AU - de Kreuk, Bart-Jan AU - Gingras, Alexandre R AU - Knight, James DR AU - Liu, Jian J AU - Gingras, Anne-Claude AU - Ginsberg, Mark H A2 - Alitalo, Kari VL - 5 PY - 2016 DA - 2016/01/19 SP - e11394 C1 - eLife 2016;5:e11394 DO - 10.7554/eLife.11394 UR - https://doi.org/10.7554/eLife.11394 AB - Heart of Glass (HEG1), a transmembrane receptor, and Rasip1, an endothelial-specific Rap1-binding protein, are both essential for cardiovascular development. Here we performed a proteomic screen for novel HEG1 interactors and report that HEG1 binds directly to Rasip1. Rasip1 localizes to forming endothelial cell (EC) cell-cell junctions and silencing HEG1 prevents this localization. Conversely, mitochondria-targeted HEG1 relocalizes Rasip1 to mitochondria in cells. The Rasip1-binding site in HEG1 contains a 9 residue sequence, deletion of which abrogates HEG1’s ability to recruit Rasip1. HEG1 binds to a central region of Rasip1 and deletion of this domain eliminates Rasip1’s ability to bind HEG1, to translocate to EC junctions, to inhibit ROCK activity, and to maintain EC junctional integrity. These studies establish that the binding of HEG1 to Rasip1 mediates Rap1-dependent recruitment of Rasip1 to and stabilization of EC cell-cell junctions. KW - Rasip1 KW - Heart of Glass KW - endothelial cells KW - Rho Kinase KW - Rap1 JF - eLife SN - 2050-084X PB - eLife Sciences Publications, Ltd ER -