Orphan receptor. Ligands are likely small molecules, either sharing some similarities with trace amine as, e.g. derivatives of indolamines (such as 5-methoxytryptamine) or of phenylethylamines (such as phenylethanolamine) or being any kind of metabolite of amino acids or biogenic amine neurotransmitters.
Expressed almost exclusively in skeletal muscle and selected areas of the brain, such amygdala, hippocampus, caudate nucleus, thalamus and hypothalamus. Weak expression is also find in substantia nigra.
Belongs to the G-protein coupled receptor 1 family.