The review article by Timo D. Müller et al. explores the multifaceted nature of the gastrointestinal peptide hormone ghrelin. Since its discovery less than 20 years ago research has broadened and elucidated our understanding of ghrelin as more than a hunger hormone. This article discusses the diverse biological functions of ghrelin, the regulation of its secretion, and addresses questions that still remain 15 years after its discovery.
The cover image illustrates the post-translational processing and acylation of ghrelin. The hormone is encoded by the preproghrelin gene, which, in addition to ghrelin, also encodes for a small signal peptide and the 23 amino acid peptide obestatin. To activate its only known receptor, ghrelin requires the attachment of a fatty acid side-chain (preferably C8 or C10) to its serine 3 residue, a rare post-translational modification (acylation) that is achieved by the ghrelin O-acyl-transferase (GOAT). This modification is required for ghrelin’s effects on systemic metabolism.Full Text