title: Discovery of a novel insect neuropeptide signaling system closely related to the insect adipokinetic hormone and corazonin hormonal systems.
abstract: Neuropeptides and their G protein-coupled receptors (GPCRs) play a central role in the physiology of insects. One large family of insect neuropeptides are the adipokinetic hormones (AKHs), which mobilize lipids and carbohydrates from the insect fat body. Other peptides are the corazonins that are structurally related to the AKHs but represent a different neuropeptide signaling system. We have previously cloned an orphan GPCR from the malaria mosquito Anopheles gambiae that was structurally intermediate between the A. gambiae AKH and corazonin GPCRs. Using functional expression of the receptor in cells in cell culture, we have now identified the ligand for this orphan receptor as being pQVTFSRDWNAamide, a neuropeptide that is structurally intermediate between AKH and corazonin and that we therefore named ACP (AKH/corazonin-related peptide). ACP does not activate the A. gambiae AKH and corazonin receptors and, vice versa, AKH and corazonin do not activate the ACP receptor, showing that the ACP/receptor couple is an independent and so far unknown peptidergic signaling system. Because ACP is structurally intermediate between AKH and corazonin and the ACP receptor between the AKH and corazonin receptors, this is a prominent example of receptor/ligand co-evolution, probably originating from receptor and ligand gene duplications followed by mutations and evolutionary selection, thereby yielding three independent hormonal systems. The ACP signaling system occurs in the mosquitoes A. gambiae, Aedes aegypti, and Culex pipiens (Diptera), the silkworm Bombyx mori (Lepidoptera), the red flour beetle Tribolium castaneum (Coleoptera), the parasitic wasp Nasonia vitripennis (Hymenoptera), and the bug Rhodnius prolixus (Hemiptera). However, the ACP system is not present in 12 Drosophila species (Diptera), the honeybee Apis mellifera (Hymenoptera), the pea aphid Acyrthosiphon pisum (Hemiptera), the body louse Pediculus humanus (Phthiraptera), and the crustacean Daphnia pulex, indicating that it has been lost several times during arthropod evolution. In particular, this frequent loss of hormonal systems is unique for arthropods compared with vertebrates.
authors.affiliation: Center for Functional and Comparative Insect Genomics, Department of Biology, University of Copenhagen, DK-2100 Copenhagen, Denmark.
authors.forename: Karina K
authors.initials: KK
authors.lastname: Hansen
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Stafflinger
authors.forename: Martina
authors.initials: M
authors.lastname: Schneider
authors.forename: Frank
authors.initials: F
authors.lastname: Hauser
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Cazzamali
authors.forename: Michael
authors.initials: M
authors.lastname: Williamson
authors.forename: Martin
authors.initials: M
authors.lastname: Kollmann
authors.forename: Joachim
authors.initials: J
authors.lastname: Schachtner
authors.forename: Cornelis J P
authors.initials: CJ
authors.lastname: Grimmelikhuijzen
mesh_terms: D000330:Aedes / Q000235:genetics / Q000378:metabolism; D000818:Animals; D000852:Anopheles / Q000235:genetics / Q000378:metabolism; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D004330:Drosophila / Q000235:genetics / Q000378:metabolism; D019143:Evolution, Molecular; D017344:Genes, Insect; D007124:Immunoenzyme Techniques; D007301:Insect Hormones / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D007313:Insecta / Q000235:genetics / Q000378:metabolism*; D009479:Neuropeptides / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D009842:Oligopeptides / Q000378:metabolism*; D010802:Phylogeny; D011761:Pyrrolidonecarboxylic Acid / Q000031:analogs & derivatives* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D043562:Receptors, G-Protein-Coupled / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D018013:Receptors, Neuropeptide / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D014231:Tribolium / Q000235:genetics / Q000378:metabolism
chemical_list: D007301:Insect Hormones; D019476:Insect Proteins; D009479:Neuropeptides; D009842:Oligopeptides; D012333:RNA, Messenger; D043562:Receptors, G-Protein-Coupled; D018013:Receptors, Neuropeptide; C044833:adipokinetic hormone; C060602:corazonin protein, insect; D011761:Pyrrolidonecarboxylic Acid