Physiological role of ghrelin as revealed by the ghrelin and GOAT knockout mice

• Published in: Peptides (New York, N.Y. : 1980) Vol. 32; no. 11; pp. 2236 - 2241
• Main Authors: Kang, Kihwa, Zmuda, Erik, Sleeman, Mark W.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.11.2011
• Subjects: acyltransferases; Acyltransferases - deficiency; Acyltransferases - genetics; Animals; Diet, High-Fat - adverse effects; Eating - drug effects; Eating - genetics; energy intake; energy metabolism; Energy Metabolism - drug effects; Energy Metabolism - genetics; Fasting - adverse effects; fatty acids; Gastric Mucosa - metabolism; Gene Deletion; Gene Expression; Genetic Association Studies; Genotype; Ghrelin; Ghrelin - deficiency; Ghrelin - genetics; Ghrelin O-acyltransferase; GHS-R; Glucose - metabolism; Glycemia; Homeostasis - drug effects; Homeostasis - genetics; Humans; knockout mutants; Mice; Mice, Knockout; Null phenotype; Organ Specificity - physiology; Phenotype; proteins; Receptors, Ghrelin - metabolism; serine; Signal Transduction; transcription (genetics); Ghrelin O-acyltransferase; Ghrelin; GHS-R; Glycemia; Null phenotype
• ISSN: 0196-9781; 1873-5169
• DOI: 10.1016/j.peptides.2011.04.028

► Similarities and difference in the phenotypes of genetic deletion ghrelin and GOAT knockout mouse lines are reported. ► Overlapping expression patterns are discussed. ► Expression pattern of ghrelin and GOAT suggests that additional peptides may be acylated by GOAT. Ghrelin is a gastric hormone that has been shown to regulate food intake and energy metabolism. One unique feature of ghrelin is that its activity is regulated post transcriptionally by ghrelin O-acyltransferase (GOAT) through the addition of fatty acid to the serine residue in the N terminal region. Despite much biochemical characterization, to date no other proteins have been shown to be specifically octonylated by GOAT, suggesting a unique matching of the acyl transferase for a single ligand, ghrelin. If this is indeed correct, then genetic deletion of ghrelin or GOAT should produce near identical phenotypes and there should be extensive overlap in expression patterns. This review summarizes the similarities and differences in the phenotypes with the genetic deletion of ghrelin and GOAT in the various knockout mouse lines reported to date. While there is considerable overlap in expression pattern between ghrelin and GOAT, the latter does exhibit some unique tissue expression that could suggest that additional peptides may be acylated and await discovery and characterization.