FXPRL-amide peptides induce ecdysteroidogenesis through a G-protein coupled receptor expressed in the prothoracic gland of Bombyx mori.
The FXPRL-amide peptide family (pyrokinin/PBAN family) consists of insect peptides that function broadly in insect life processes and are characterized by a conserved C-terminal motif. In the silkworm, Bombyx mori, sex pheromone biosynthesis and induction of embryonic diapause are regulated by peptides from this family. To elucidate other functions of Bombyx FXPRL-amide peptides, we analyzed the tissue expression patterns of two known Bombyx G-protein coupled receptors for these peptides. We found that the Bombyx diapause hormone receptor (BmDHR), is expressed in the prothoracic gland (PG), the organ which synthesizes and releases the insect molting hormones, ecdysteroids. Furthermore, diapause hormone (DH), a member of the Bombyx FXPRL-amide peptides, increases both intracellular Ca(2+) and cAMP concentrations and induces ecdysteroidogenesis in late fifth instar PGs coincident with BmDHR expression in the PGs. DH also has the highest prothoracicotropic activity among the FXPRL-amide peptides, which corresponds well to the ligand specificity of heterologously expressed BmDHR. These results demonstrate that FXPRL-amide peptides can function as prothoracicotropic factors through the activation of BmDHR and may play an important role in controlling molting and metamorphosis.
Watanabe
Ken
K
Department of Integrated Biosciences, Room 201, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan.
Hull
J Joe
JJ
Niimi
Teruyuki
T
Imai
Kunio
K
Matsumoto
Shogo
S
Yaginuma
Toshinobu
T
Kataoka
Hiroshi
H
D000595:Amino Acid Sequence; D000818:Animals; D012831:Bombyx / Q000187:drug effects* / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism; D026461:Ecdysteroids / Q000096:biosynthesis*; D004789:Enzyme Activation / Q000187:drug effects; D005786:Gene Expression Regulation / Q000187:drug effects; D007814:Larva / Q000187:drug effects; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000494:pharmacology; D009865:Oocytes; D010455:Peptides / Q000737:chemistry / Q000494:pharmacology*; D043562:Receptors, G-Protein-Coupled / Q000235:genetics / Q000378:metabolism*; D013909:Thorax / Q000187:drug effects* / Q000378:metabolism*; D010738:Type C Phospholipases / Q000378:metabolism; D014981:Xenopus
D026461:Ecdysteroids; D009479:Neuropeptides; D010455:Peptides; D043562:Receptors, G-Protein-Coupled; C075027:diapause hormone; D000242:Cyclic AMP; D010738:Type C Phospholipases; D002118:Calcium