Motilin Receptor (MLNR)

Motilin receptor is a G protein-coupled receptor that binds motilin. Motilin in turn is an intestinal peptide that stimulates contraction of gut smooth muscle. The growth hormone secretagogue receptor (GHSR) is a G protein-coupled receptor found in the pituitary gland and brain that is involved in the control of growth hormone release. McKee et al.  identified 2 human genes related to GHSR: GPR38 and GPR39. The predicted 438-amino acid GPR38 protein contains the 7 transmembrane domains characteristic of G protein-coupled receptors. The amino acid sequences of GPR38 and GSHR are 52% identical. RNase protection studies revealed that GPR38 is expressed only in thyroid, stomach, and bone marrow.