Galanin receptor
The galanin receptor is a G protein-coupled receptor, or metabotropic receptor which binds galanin. Galanin receptors can be found throughout the peripheral and central nervous systems and the endocrine system. So far three subtypes are known to exist: GAL-R1, GAL-R2, and GAL-R3. The specific function of each subtype remains to be fully elucidated, although as of 2009 great progress is currently being made in this respect with the generation of receptor subtype-specific knockout mice, and the first selective ligands for galanin receptor subtypes. Selective galanin agonists are anticonvulsant, while antagonists produce antidepressant and anxiolytic effects in animals, so either agonist or antagonist ligands for the galanin receptors may be potentially therapeutic compounds in humans. Ligands Agonists Non-selective Galanin Galanin 1-15 fragment Galanin-like peptide - agonist at GAL1 and GAL2 but not GAL3 Galmic Galnon NAX 5055 D-Gal(7-Ahp)-B2 GAL1 selective M617 GAL1/2 selective M1154 - has no GalR3 interaction GAL2 selective Galanin 2-11 amide - also called AR-M 1896, anticonvulsant in mice, CAS# 367518-31-8 M1145 - selective compared to both GalR1 and GalR3 M1153 - selective compared to both GalR1 and GalR3 CYM 2503 (positive allosteric modulator) Antagonists Non-selective M35 peptide GAL1 selective SCH-202,596 GAL2 selective M871 peptide GAL3 selective SNAP-37889