Motilin receptor is a G protein-coupled receptor (previously GPCR38)[3][4][5] that binds motilin.[6][7] It was first cloned in 1999 by Merck Laboratories.[8] and scientists have since been searching for compounds to modify its behavior.[9]
The primary structure of the motilin receptor consists of 412 amino acids,[8] while its tertiary structure resembles a golf club.[10] The protein C-terminal protein protects from enzymatic degradation, while the N-terminal is essential for binding.[10]
Function
The primary function of the motilin receptor is to contract gastric smooth muscle during phase III of the migrating motor complex (MMC).[8] In this final phase of the MMC, N-type motilin receptors in the distal antral pump of the stomach are activated.[11] This causes contraction of the gastric smooth muscle, sieving food into the small intestine, and priming the stomach for the next meal.[12]
Motilin
Motilin is an intestinal
gastric motility in patients with gastroparesis e.g., constipation-predominant irritable bowel syndrome.[15] However, none of the candidate drugs that have been tested so far have made it to market.[4][16]
Smith RG, Leonard R, Bailey AR, Palyha O, Feighner S, Tan C, et al. (February 2001). "Growth hormone secretagogue receptor family members and ligands". Endocrine. 14 (1): 9–14.
McKee KK, Tan CP, Palyha OC, Liu J, Feighner SD, Hreniuk DL, et al. (December 1997). "Cloning and characterization of two human G protein-coupled receptor genes (GPR38 and GPR39) related to the growth hormone secretagogue and neurotensin receptors". Genomics. 46 (3): 426–434.
Feighner SD, Tan CP, McKee KK, Palyha OC, Hreniuk DL, Pong SS, et al. (June 1999). "Receptor for motilin identified in the human gastrointestinal system". Science. 284 (5423): 2184–2188.
Miller P, Roy A, St-Pierre S, Dagenais M, Lapointe R, Poitras P (January 2000). "Motilin receptors in the human antrum". American Journal of Physiology. Gastrointestinal and Liver Physiology. 278 (1): G18–G23.
Thielemans L, Depoortere I, Van Assche G, Bender E, Peeters TL (March 2001). "Demonstration of a functional motilin receptor in TE671 cells from human cerebellum". Brain Research. 895 (1–2): 119–128.
Thielemans L, Depoortere I, Vanden Broeck J, Peeters TL (May 2002). "The motilin pharmacophore in CHO cells expressing the human motilin receptor". Biochemical and Biophysical Research Communications. 293 (4): 1223–1227.
Depoortere I, Thijs T, Thielemans L, Robberecht P, Peeters TL (May 2003). "Interaction of the growth hormone-releasing peptides ghrelin and growth hormone-releasing peptide-6 with the motilin receptor in the rabbit gastric antrum". The Journal of Pharmacology and Experimental Therapeutics. 305 (2): 660–667.
"Motilin Receptors: Motilin". IUPHAR Database of Receptors and Ion Channels. International Union of Basic and Clinical Pharmacology. Archived from the original on 2011-05-16. Retrieved 2007-10-25.
