Characterization of the adipokinetic hormone receptor of the anautogenous flesh fly, Sarcophaga crassipalpis. (June 2016)

• Record Type: Journal Article
• Authors: Bil, Magdalena; Timmermans, Iris; Verlinden, Heleen; Huybrechts, Roger
• Is Part Of: Journal of insect physiology. Volume 89(2016:Jun.)
• Page Start: 52
• Page End: 59
• Publication Date: 2016-06
• Subjects: Adipokinetic hormone -- Adipokinetic hormone receptor -- G protein-coupled receptor -- Differential expression -- Flesh fly -- Anautogeny; Insects -- Physiology -- Periodicals; Insectes -- Physiologie -- Périodiques; Insects -- Physiology; Periodicals; 571.157
• DOI: 10.1016/j.jinsphys.2016.04.001
• Languages: English
• ISSNs: 0022-1910

Abstract

Graphical abstract: Highlights: Sarcophaga crassipalpis adipokinetic hormone receptor ( Sarcr AKHR), GPCR, was cloned and pharmacologically characterized. Tissue distribution of AKH and its receptor were analyzed in S. crassipalpis. AKHR transcript levels decrease in protein fed female flies. Abstract: Adipokinetic hormone (AKH) is an insect neuropeptide mainly involved in fat body energy mobilization. In flies ( Phormia regina, Sarcophaga crassipalpis ), bugs ( Pyrrhocoris apterus ) and cockroaches ( Periplaneta americana ) AKH was also demonstrated to be involved in the regulation of digestion. This makes AKH an important peptide for anautogenous female flies that need to feed on a supplementary protein meal to initiate vitellogenesis, the large scale synthesis of yolk proteins and their uptake by the developing oocytes. Flesh fly AKH, originally identified as Phormia terraenovae hypertrehalosemic hormone ( Phote HrTH), functions through activation of the AKH receptor (AKHR). This is a G protein-coupled receptor that is the orthologue of the human gonadotropin-releasing hormone receptor. Pharmacological characterization indicated that the receptor can be activated by two related dipteran AKH ligands with an EC50 value in the low nanomolar range, whereas micromolar concentrations of the Tribolium castaneum AKH were needed. Consistent with the energy mobilizing function of AKH, the receptor transcript levels were most abundant in the fat body tissue. Nonetheless, Sarcophaga crassipalpis AKHR transcript levels were also high in the brain, the foregut and the hindgut. Interestingly, the receptor transcript numbers were reduced in almost all measured tissues after protein feeding. These changes may enforce the use of ingested energy carrying molecules prior to stored energy mobilization.