Receptor that plays a role in the regulation of synaptogenesis and dendritic spine formation at least partly via interaction with ELMO1 and RAC1 activity (By similarity). Promotes myoblast fusion through ELMO/DOCK1 (PubMed:24567399). Forms a heterodimer, consisting of a large extracellular region non-covalently linked to a seven-transmembrane moiety. Interacts (via TSP N-terminal domains) with C1QL1, C1QL2, C1QL3 and C1QL4 (PubMed:21262840). Interacts with ELMO1, ELMO2 AND ELMO3 (PubMed:24567399). Strongly expressed in brain. Also detected in heart. Reduced expression in some glioblastoma cell lines. The endogenous protein is proteolytically cleaved into 2 subunits, an extracellular subunit and a seven-transmembrane subunit. Autoproteolysis appears to be cell specific, does not readily undergo proteolytic cleavage in HEK293T cells. Belongs to the G-protein coupled receptor 2 family. Adhesion G-protein coupled receptor (ADGR) subfamily. Extended N-terminus.