This gene product belongs to the G-protein coupled receptor 1 family. Even though this protein shares similarity with the melatonin receptors, it does not bind melatonin, however, it inhibits melatonin receptor 1A function through heterodimerization. Polymorphic variants of this gene have been associated with bipolar affective disorder in women. [provided by RefSeq, Jan 2010] see less This gene product belongs to the G-protein coupled receptor 1 family. Even though this protein shares similarity with the melatonin receptors, it does not bind melatonin, however, it inhibits melatonin receptor 1A function through heterodimerization. Polymorphic variants of this gene have been associated with bipolar affective disorder in women. [provided by RefSeq, Jan 2010]