title: Colocalization of ghrelin O-acyltransferase and ghrelin in gastric mucosal cells.
abstract: Ghrelin is a peptide hormone with many known functions, including orexigenic, blood glucose-regulatory, and antidepressant actions, among others. Mature ghrelin is unique in that it is the only known naturally occurring peptide to be posttranslationally modified by O-acylation with octanoate. This acylation is required for many of ghrelin's actions, including its effects on promoting increases in food intake and body weight. GOAT (ghrelin O-acyltransferase), one of 16 members of the MBOAT family of membrane-bound O-acyltransferases, has recently been identified as the enzyme responsible for catalyzing the addition of the octanoyl group to ghrelin. Although the initial reports of GOAT have localized its encoding mRNA to tissues known to contain ghrelin, it is as yet unclear whether the octanoylation occurs within ghrelin-producing cells or in neighboring cells. Here, we have performed dual-label histochemical analysis on mouse stomach sections and quantitative PCR on mRNAs from highly enriched pools of mouse gastric ghrelin cells to demonstrate a high degree of GOAT mRNA expression within ghrelin-producing cells of the gastric oxyntic mucosa. We also demonstrate that GOAT is the only member of the MBOAT family whose expression is highly enriched within gastric ghrelin cells and whose whole body distribution mirrors that of ghrelin.
authors.affiliation: Department of Internal Medicine, The University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9077, USA.
authors.forename: Ichiro
authors.initials: I
authors.lastname: Sakata
authors.forename: Jing
authors.initials: J
authors.lastname: Yang
authors.forename: Charlotte E
authors.initials: CE
authors.lastname: Lee
authors.forename: Sherri
authors.initials: S
authors.lastname: Osborne-Lawrence
authors.forename: Sherry A
authors.initials: SA
authors.lastname: Rovinsky
authors.forename: Joel K
authors.initials: JK
authors.lastname: Elmquist
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Zigman
mesh_terms: D000123:Acetyltransferases / Q000235:genetics / Q000378:metabolism; D000217:Acyltransferases / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D002478:Cells, Cultured; D004386:Duodenum / Q000378:metabolism; D005753:Gastric Mucosa / Q000378:metabolism*; D054439:Ghrelin / Q000235:genetics / Q000378:metabolism*; D008297:Male; D008565:Membrane Proteins; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D014018:Tissue Distribution
chemical_list: D054439:Ghrelin; D008565:Membrane Proteins; D000217:Acyltransferases; D000123:Acetyltransferases; C526983:Mboat4 protein, mouse