title: Receptor guanylyl cyclases in Inka cells targeted by eclosion hormone.
abstract: A signature of eclosion hormone (EH) action in insect ecdysis is elevation of cGMP in Inka cells, leading to massive release of ecdysis triggering hormone (ETH) and ecdysis initiation. Although this aspect of EH-induced signal transduction is well known, the receptor mediating this process has not been identified. Here, we describe a receptor guanylyl cyclase BdmGC-1 and its isoform BdmGC-1B in the Oriental fruit fly Bactrocera dorsalis that are activated by EH. The B form exhibits the conserved domains and putative N-glycosylation sites found in BdmGC-1, but possesses an additional 46-amino acid insertion in the extracellular domain and lacks the C-terminal tail of BdmGC-1. Combined immunolabeling and in situ hybridization reveal that BdmGC-1 is expressed in Inka cells. Heterologous expression of BdmGC-1 in HEK cells leads to robust increases in cGMP following exposure to low picomolar concentrations of EH. The B-isoform responds only to higher EH concentrations, suggesting different physiological roles of these cyclases. We propose that BdmGC-1 and BdmGC-1B are high- and low-affinity EH receptors, respectively.
authors: Department of Entomology, National Chung Hsing University, Taichung, Taiwan 40227, Republic of China.
authors: Jer-Cherng
authors: JC
authors: Chang
authors: Ruey-Bing
authors: RB
authors: Yang
authors: Michael E
authors: ME
authors: Adams
authors: Kuang-Hui
authors: KH
authors: Lu
mesh_terms: D000818:Animals; D002460:Cell Line; D006152:Cyclic GMP / Q000378:metabolism; D006031:Glycosylation / Q000187:drug effects; D006801:Humans; D007301:Insect Hormones / Q000494:pharmacology*; D008954:Models, Biological; D008969:Molecular Sequence Data; D020033:Protein Isoforms / Q000378:metabolism; D021381:Protein Transport / Q000187:drug effects; D050705:Receptors, Guanylate Cyclase-Coupled / Q000378:metabolism*; D040681:Structural Homology, Protein; D033621:Tephritidae / Q000187:drug effects / Q000378:metabolism*; D014132:Trachea / Q000166:cytology / Q000187:drug effects / Q000378:metabolism
chemical_list: D007301:Insect Hormones; D020033:Protein Isoforms; C042645:eclosion hormone; D050705:Receptors, Guanylate Cyclase-Coupled; D006152:Cyclic GMP