Regulation of insulin and adipokinetic hormone/glucagon production in flies

Abstract

Metabolic homeostasis is under strict regulation of humoral factors across various taxa. In particular, insulin and glucagon, referred to in Drosophila as Drosophila insulin-like peptides (DILPs) and adipokinetic hormone (AKH), respectively, are key hormones that regulate metabolism in most metazoa. While much is known about the regulation of DILPs, the mechanisms regulating AKH/glucagon production is still poorly understood. In this review, we describe the various factors that regulate the production of DILPs and AKH and emphasize the need for future studies to decipher how energy homeostasis is governed in Drosophila. This article is categorized under: Invertebrate Organogenesis > Flies Signaling Pathways > Global Signaling Mechanisms.

Keywords: AKH; Drosophila; hormone; insulin.

FIGURE 1

(a) Amino acid sequence alignment of DILP1, 2, 3 and 5 with human insulin. Conserved characteristic of cystine residues have been highlighted. (b) Amino acid sequence alignment of fly AKH with human glucagon

FIGURE 2

Conserved mechanism of glucose sensing in Drosophila and mammals. Mammals express ATP-sensitive potassium channels on pancreatic β-cells, enabling them to sense dietary sugars and produce insulin. Similarly, Drosophila expresses these orthologous channels on insulin-producing cells, which subsequently produce DILPs. Metabolic signaling converges on insulin-mediated TOR signaling