title: Functional phylogenetics reveals contributions of pleiotropic peptide action to ligand-receptor coevolution.
abstract: The evolution of peptidergic signaling has been accompanied by a significant degree of ligand-receptor coevolution. Closely related clusters of peptide signaling molecules are observed to activate related groups of receptors, implying that genes encoding these ligands may orchestrate an array of functions, a phenomenon known as pleiotropy. Here we examine whether pleiotropic actions of peptide genes might influence ligand-receptor coevolution. Four test groups of neuropeptides characterized by conserved C-terminal amino acid sequence motifs and their cognate receptors were examined in the red flour beetle (Tribolium castaneum): 1) cardioacceleratory peptide 2b (CAPA); CAPAr, 2) pyrokinin/diapause hormone (PK1/DH); PKr-A, -B, 3) pyrokinin/pheromone biosynthesis activating hormone (PK2/PBAN); PKr-C, and 4) ecdysis triggering hormone (ETH); ETHr-b. Ligand-receptor specificities were established through heterologous expression of receptors in cell-based assays for 9 endogenous ligands. Based on ligand-receptor specificity analysis, we found positive pleiotropism exhibited by ETH on ETHR-b and CAPAr, whereas PK1/DH and CAPA are more highly selective for their respective authentic receptors than would be predicted by phylogenetic analysis. Disparities between evolutionary trees deduced from receptor sequences vs. functional ligand-receptor specificities lead to the conclusion that pleiotropy exhibited by peptide genes influences ligand-receptor coevolution.
authors.affiliation: 1] Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing 400715, P. R. China [2] Department of Entomology, Kansas State University, Manhattan, Kansas 66506, United States.
authors.forename: Hongbo
authors.initials: H
authors.lastname: Jiang
authors.affiliation: Department of Entomology, Kansas State University, Manhattan, Kansas 66506, United States.
authors.forename: Zhaojun
authors.initials: Z
authors.lastname: Wei
authors.affiliation: Insect Control and Cotton Disease Research Unit, Southern Plains Agricultural Research Center, USDA, 2881 F/B Road, College Station, TX 77845, USA.
authors.forename: Ronald J
authors.initials: RJ
authors.lastname: Nachman
authors.affiliation: Departments of Entomology and Cell Biology &Neuroscience, 2103 Biological Sciences Building, University of California, Riverside, CA 92521, USA.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Adams
authors.affiliation: Department of Entomology, Kansas State University, Manhattan, Kansas 66506, United States.
authors.forename: Yoonseong
authors.initials: Y
authors.lastname: Park
mesh_terms: D000818:Animals; D019143:Evolution, Molecular; D008024:Ligands; D009479:Neuropeptides / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D009842:Oligopeptides / Q000096:biosynthesis / Q000235:genetics*; D010802:Phylogeny; D011761:Pyrrolidonecarboxylic Acid / Q000031:analogs & derivatives*; D015398:Signal Transduction; D014231:Tribolium / Q000235:genetics / Q000378:metabolism
chemical_list: D008024:Ligands; D009479:Neuropeptides; D009842:Oligopeptides; C095817:cardioacceleratory peptide 2b; C079709:pheromone biosynthesis activating neuropeptide, Helicoverpa zea; C079229:pyrokinin; D011761:Pyrrolidonecarboxylic Acid