title: G protein-coupled receptor for diapause hormone, an inducer of Bombyx embryonic diapause.
abstract: Bombyx diapause hormone was the first chemical substance identified as a maternal control factor that arrests offspring development. However, the molecular mechanisms by which the hormone transduces the signal to the oocyte that induces embryonic diapause immediately after mesoderm segmentation are not fully understood. Here, we describe a cDNA for a G protein-coupled diapause hormone receptor with seven transmembrane domains. Its amino-acid sequence shows a high level of similarity to the receptors of mammalian neuromedin U and insect regulatory peptide, an FXPRL-amide C-terminus. When expressed in a Xenopus oocyte system, the receptor exhibited the highest affinity (EC(50), approximately 70nM) for diapause hormone, when compared with other Bombyx FXPR/KL-amide peptides. Diapause hormone without amidation at the C-terminus, which never induces embryonic diapause in vivo, had no effect in this heterologous expression system. The mRNA is expressed in the ovaries during Bombyx pupal-adult development. These results strongly indicate that the cDNA encodes the diapause hormone receptor.
authors.affiliation: Sericulture and Entomoresources, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya 464-8601, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Homma
authors.forename: Ken
authors.initials: K
authors.lastname: Watanabe
authors.forename: Shuichiro
authors.initials: S
authors.lastname: Tsurumaru
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kataoka
authors.forename: Kunio
authors.initials: K
authors.lastname: Imai
authors.forename: Mari
authors.initials: M
authors.lastname: Kamba
authors.forename: Teruyuki
authors.initials: T
authors.lastname: Niimi
authors.forename: Okitsugu
authors.initials: O
authors.lastname: Yamashita
authors.forename: Toshinobu
authors.initials: T
authors.lastname: Yaginuma
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D012831:Bombyx / Q000196:embryology* / Q000235:genetics / Q000378:metabolism; D018076:DNA, Complementary / Q000235:genetics; D005260:Female; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000378:metabolism*; D010053:Ovary / Q000378:metabolism; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism; D043562:Receptors, G-Protein-Coupled / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D014981:Xenopus
chemical_list: D018076:DNA, Complementary; D009479:Neuropeptides; D012333:RNA, Messenger; D043562:Receptors, G-Protein-Coupled; C075027:diapause hormone