galactose/rhamnose binding lectin domain found in latrophilins
Latrophilins, also called lectomedins or latrotoxin receptors, belong to Group I adhesion GPCRs, which also include ETL (EGF-TM7-latrophilin-related protein). These receptors are a member of the adhesion family (subclass B2) that belongs to the class B GPCRs. Three subtypes of latrophilins have been identified: latrophilin-1 (LPHN1), Latrophilin-2 (LPHN2), and Latrophilin-3 (LPHN3). The LPHN1 is a brain-specific calcium-independent receptor of alpha-latrotoxin, a potent presynaptic neurotoxin from the venom of the black widow spider that induces massive neurotransmitter release from sensory and motor neurons as well as endocrine cells, leading to nerve-terminal degeneration. LPHN2 and LPHN3, although sharing strong sequence homology to LPHN1, do not bind alpha-latrotoxin. While LPHN3 is also brain specific, LPHN2, is ubiquitously distributed. The endogenous ligands for these two receptors are unknown. All members in this family contain a galactose/rhamnose-binding lectin domain at N-terminus.
Jiyao W et al.(2023). "The conserved domain database in 2023.",