Plays a role in cell-cell adhesion and neuron guidance via its interactions with FLRT2 and FLRT3 that are expressed at the surface of adjacent cells. Plays a role in the development of glutamatergic synapses in the cortex. Important in determining the connectivity rates between the principal neurons in the cortex. Interacts (via olfactomedin-like domain) with FLRT3 (via extracellular domain); the interaction is direct. Identified in a complex with FLRT3 and UNC5B; does not interact with UNC5B by itself. Identified in a complex with FLRT3 and UNC5D; does not interact with UNC5D by itself (By similarity). Interacts (via olfactomedin-like domain) with FLRT1 (via extracellular domain). Interacts (via olfactomedin-like domain) with FLRT2 (via extracellular domain). Interacts (via extracellular domain) with TENM1. Interacts (via extracellular domain) with TENM3 (By similarity). Brain-specific distribution but low levels are also detected in lung and spleen. The Olfactomedin-like domain is required for the synapse-promoting function and the interaction with FLRT3. The Olfactomedin-like and the SUEL-type lectin domains are required for the interaction with TENM1 (By similarity). Proteolytically cleaved into 2 subunits, an extracellular subunit and a seven-transmembrane subunit. O-glycosylated (major) and N-glycosylated. Belongs to the G-protein coupled receptor 2 family. LN-TM7 subfamily.