Two identified transcript variants are expressed in several tissues and are evolutionary conserved in fish and swine. One transcript, 1a, excises an intron and encodes the functional protein; this protein is the receptor for the ghrelin ligand and defines a neuroendocrine pathway for<unk><unk>  release. The second transcript (1b) retains the intron and does not function as a receptor for ghrelin; however, it may function to attenuate activity of isoform 1a.<unk> 1a falls into G-protein-coupled receptor (GPCR) family. Previous studies have shown that GPCRs can form heterodimers, or functional receptor pairs with other types of G-protein coupled receptors (GPCRs). Various studies suggest that<unk> 1a specifically forms dimers with the following<unk>  and neurotransmitter receptors: somatostatin receptor 5, dopamine receptor type 2 (DRD2), melanocortin-3 receptor (MC3R), and serotonin receptor type 2C (5-HT2c receptor). See "Function" section below for details on the purported functions of these heterodimers.
Growth hormone secretagogue receptor
Prolactin-releasing peptide receptor
Cystic fibrosis transmembrane conductance regulator
Vitamin D receptor
Hydroxycarboxylic acid receptor 2
Heart-type fatty acid binding protein
Xenobiotic-sensing receptor
G protein-coupled receptor kinase 3