G protein-coupled receptor for diapause hormone, an inducer of Bombyx embryonic diapause.
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.
Homma
Takashi
T
Sericulture and Entomoresources, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya 464-8601, Japan.
Watanabe
Ken
K
Tsurumaru
Shuichiro
S
Kataoka
Hiroshi
H
Imai
Kunio
K
Kamba
Mari
M
Niimi
Teruyuki
T
Yamashita
Okitsugu
O
Yaginuma
Toshinobu
T
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
D018076:DNA, Complementary; D009479:Neuropeptides; D012333:RNA, Messenger; D043562:Receptors, G-Protein-Coupled; C075027:diapause hormone